Tropical Medicine publications 2016

Tuan Anh N, Nga TVT, Tuan HM, Tuan NS, Y DM, Chau NVV, Baker S, Duong HHT. 2016. The molecular epidemiology and antimicrobial resistance phenotypes of Acinetobacter baumannii isolated from patients in three hospitals in southern Vietnam. J Med Microbiol, 66 (1), pp. 46-53. | Citations: 1 (Web of Science Lite) | Show Abstract | Read more

Multidrug resistance (MDR) in the nosocomial pathogen Acinetobacter baumannii limits therapeutic options and impacts on clinical care. Resistance against carbapenems, a group of last-resort antimicrobials for treating MDR A. baumannii infections, is associated with the expression (and over-expression) of carbapenemases encoded by the blaOXA genes. The aim of this study was to determine the prevalence of antimicrobial resistant A. baumannii associated with infection in three hospitals in southern Vietnam and to characterise the genetic determinants associated with resistance against carbapenems. We recovered a total of 160 A. baumannii isolates from clinical samples collected in three hospitals in southern Vietnam from 2012 to 2014. Antimicrobial resistance was common; 119/160 (74%) of isolates were both MDR and extensively drug resistant (XDR). High-level imipenem resistance (>32µg/ml) was determined for 109/117 (91.6%) of the XDR imipenem non-susceptible organisms, of which the majority (86.7%) harboured the blaOXA-51 and blaOXA-23 genes associated with an ISAba1 element. Multiple-locus variable number tandem repeat analysis (MLVA) segregated the 160 A. baumannii into 107 different MLVA types, which described five major clusters. The biggest cluster was a clonal complex comprised mainly of imipenem resistant organisms that were isolated from all three of the study hospitals. Our study indicates a very high prevalence of MDR/XDR A. baumannii causing clinically significant infections in hospitals in southern Vietnam. These organisms commonly harboured the blaOXA-23 gene with ISAba1 and were carbapenem resistant; this resistance phenotype may explain their continued selection and on-going transmission within the Vietnamese healthcare system.

Murphy GAV, Gathara D, Aluvaala J, Mwachiro J, Abuya N, Ouma P, Snow RW, English M. 2016. Nairobi Newborn Study: a protocol for an observational study to estimate the gaps in provision and quality of inpatient newborn care in Nairobi City County, Kenya. BMJ Open, 6 (12), pp. e012448. | Show Abstract | Read more

INTRODUCTION: Progress has been made in Kenya towards reducing child mortality as part of efforts aligned with the fourth Millennium Development Goal. However, little advancement has been made in reducing mortality among newborns, which now accounts for 45% of all child deaths. The frequently unanticipated nature of neonatal illness, its severity and the high dependency of sick newborns on skilled care make the provision of inpatient hospital services one key component of strategies to improve newborn survival. METHODS AND ANALYSES: This project aims to assess the availability and quality of inpatient newborn care in hospitals in Nairobi City County across the public, private and not-for-profit sectors and align this to the estimated need for such services, providing a description of the quantity and quality gaps between capacity and demand. The population level burden of disease will be estimated using morbidity incidence estimates from a literature review applied to subcounty estimates of population-adjusted births, providing a spatially disaggregated estimate of need within the county. This will be followed by a survey of neonatal services across all health facilities providing 24/7 inpatient newborn care in the county. The survey will include: a retrospective audit of admission registers to estimate the usage of facilities and case-mix of patients; a structural assessment of facilities to gain insight into capacity; a questionnaire to nursing staff focusing on the process of delivering key obstetric and neonatal interventions; and a retrospective case audit to assess adherence to guidelines by clinicians. ETHICS AND DISSEMINATION: This study has been approved by the Kenya Medical Research Institute Scientific and Ethics Review Unit (SSC protocol No.2999). Results will be disseminated: to participating facilities through individualised reports and a joint workshop; to local and national stakeholders through meetings and a summary report; and to the international community through peer-review publication and international meetings.

Leang R, Khu NH, Mukaka M, Debackere M, Tripura R, Kheang ST, Chy S, Kak N, Buchy P, Tarantola A et al. 2016. Erratum to: An optimised age-based dosing regimen for single low-dose primaquine for blocking malaria transmission in Cambodia. BMC Med, 14 (1), pp. 213. | Show Abstract | Read more

© 2016 The Author(s). After publication of the original article [1], it came to the authors' attention that there was an error in the PQ pharmacokinetics sub-section of the Background section. The following sentence is affected: "There is no PK interaction between PQ and either artesunate-pyronaridine [76] or mefloquine [69, 77]; no PK interaction data exist for PQ and artemetherlumefantrine (AL)." This sentence should have read as follows: "AS pyronaridine increased PQ exposure by 15% without affecting significantly cPQ exposure [76] . There is no PK interaction between PQ and mefloquine [69, 77]; no PK interaction data exist for PQ and artemetherlumefantrine (AL).".

Rojek AM, Horby PW. 2016. Modernising epidemic science: enabling patient-centred research during epidemics. BMC Med, 14 (1), pp. 212. | Citations: 3 (Scopus) | Show Abstract | Read more

BACKGROUND: Emerging and epidemic infectious disease outbreaks are a significant public health problem and global health security threat. As an outbreak begins, epidemiological investigations and traditional public health responses are generally mounted very quickly. However, patient-centred research is usually not prioritised when planning and enacting the response. Instead, the clinical research response occurs subsequent to and separate from the public health response, and is inadequate for evidence-based decision-making at the bedside or in the offices of public health policymakers. DISCUSSION: The deficiencies of the clinical research response to severe acute respiratory syndrome, pandemic influenza, Middle East respiratory syndrome coronavirus and Ebola virus demonstrate that current research models do not adequately inform and improve the quality of clinical care or public health response. Three suggestions for improvements are made. First, integrate the data and sample collection needs for clinical and public health decision-making within a unified framework, combined with a risk-based, rather than a discipline-based, approach to ethical review and consent. Second, develop clinical study methods and tools that are specifically designed to meet the epidemiological and contextual challenges of emerging and epidemic infectious diseases. Third, invest in investigator-led clinical research networks that are primed and incentivised to respond to outbreak infections, and which can call on the support and resources of a central centre of excellence. CONCLUSIONS: It is crucial that the field of epidemic science matures to place patients at the heart of the response. This can only be achieved when patient-centred research is integrated in the outbreak response from day one and practical steps are taken to reduce the barriers to the generation of reliable and useful evidence.

Wuthiekanun V, White NJ, Amornchai P, Day NP, Limmathurotsakul D. 2016. Quality controls for antimicrobial disk diffusion testing on Leptospira Vanaporn Wuthiekanun agar. Trans R Soc Trop Med Hyg, 110 (11), pp. 673-675. | Show Abstract | Read more

BACKGROUND: Disk diffusion susceptibility testing for Leptospira spp. on Leptospira Vanaporn Wuthiekanun (LVW) solid agar was reported recently. However, it was unclear whether the zone sizes obtained on LVW agar were comparable with those of other bacteria on Mueller-Hinton agar. METHODS: Here, we evaluate the disk diffusion assay on LVW agar using the standard quality control (QC) bacterial strains for 22 antimicrobials. RESULTS: All antimicrobials provided zone sizes within the standard range for each QC bacterial strain, except for fosfomycin. CONCLUSIONS: In conclusion, the simple disk diffusion assay can be used to assess antimicrobial activity against Leptospira on LVW agar using standard bacterial strains for QC with the standard breakpoints (except for fosfomycin).

Newton PN, Timmermann B. 2016. Fake penicillin, The Third Man, and Operation Claptrap. BMJ, 355 pp. i6494. | Read more

Thanh NT, Vinh LD, Liem NT, Shikuma C, Day JN, Thwaites G, Le T. 2016. Clinical features of three patients with paradoxical immune reconstitution inflammatory syndrome associated with Talaromyces marneffei infection Medical Mycology Case Reports, | Read more

Githinji S, Noor AM, Malinga J, Macharia PM, Kiptui R, Omar A, Njagi K, Waqo E, Snow RW. 2016. A national health facility survey of malaria infection among febrile patients in Kenya, 2014. Malar J, 15 (1), pp. 591. | Citations: 4 (Scopus) | Show Abstract | Read more

BACKGROUND: The use of malaria infection prevalence among febrile patients at clinics has a potential to be a valuable epidemiological surveillance tool. However, routine data are incomplete and not all fevers are tested. This study was designed to screen all fevers for malaria infection in Kenya to explore the epidemiology of fever test positivity rates. METHODS: Random sampling was used within five malaria epidemiological zones of Kenya (i.e., high lake endemic, moderate coast endemic, highland epidemic, seasonal low transmission and low risk zones). The selected sample was representative of the number of hospitals, health centres and dispensaries within each zone. Fifty patients with fever presenting to each sampled health facility during the short rainy season were screened for malaria infection using a rapid diagnostic test (RDT). Details of age, pregnancy status and basic demographics were recorded for each patient screened. RESULTS: 10,557 febrile patients presenting to out-patient clinics at 234 health facilities were screened for malaria infection. 1633 (15.5%) of the patients surveyed were RDT positive for malaria at 124 (53.0%) facilities. Infection prevalence among non-pregnant patients varied between malaria risk zones, ranging from 0.6% in the low risk zone to 41.6% in the high lake endemic zone. Test positivity rates (TPR) by age group reflected the differences in the intensity of transmission between epidemiological zones. In the lake endemic zone, 6% of all infections were among children aged less than 1 year, compared to 3% in the coast endemic, 1% in the highland epidemic zone, less than 1% in the seasonal low transmission zone and 0% in the low risk zone. Test positivity rate was 31% among febrile pregnant women in the high lake endemic zone compared to 9% in the coast endemic and highland epidemic zones, 3.2% in the seasonal low transmission zone and zero in the low risk zone. CONCLUSION: Malaria infection rates among febrile patients, with supporting data on age and pregnancy status presenting to clinics in Kenya can provide invaluable epidemiological data on spatial heterogeneity of malaria and serve as replacements to more expensive community-based infection rates to plan and monitor malaria control.

Dance D. 2016. Melioidosis parotitis in children. J Venom Anim Toxins Incl Trop Dis, 22 (1), pp. 33. | Citations: 1 (Web of Science Lite) | Show Abstract | Read more

A recent paper published in JVATiTD reporting a child in Hainan with parotitis caused by Burkholderia pseudomallei misleadingly described parotitis as a rare manifestation of melioidosis. In fact, it is one of the commonest forms of paediatric melioidosis seen in other parts of Southeast Asia, although interestingly not in Australia.

Otter JA, Dyakova E, Bisnauthsing KN, Querol-Rubiera A, Patel A, Ahanonu C, Tosas Auguet O, Edgeworth JD, Goldenberg SD. 2016. Universal hospital admission screening for carbapenemase-producing organisms in a low-prevalence setting. J Antimicrob Chemother, 71 (12), pp. 3556-3561. | Citations: 5 (Scopus) | Show Abstract | Read more

BACKGROUND: Carbapenemase-producing Enterobacteriaceae (CPE) are an emerging threat for healthcare providers worldwide. OBJECTIVES: To determine CPE carriage rates and risk factors in an unselected hospital cohort at the time of admission. METHODS: We approached 4567 patients within 72 h of admission to provide a rectal swab and answer a questionnaire on risk factors for carriage. Rectal swabs were cultured for carbapenem-resistant organisms on chromogenic and non-chromogenic agar, and tested for carbapenemase production by PCR (Check-Direct CPE). The study was approved by the NHS Research Ethics Committee. RESULTS: Only 6 CPE were cultured from 5 (0.1%) of 4006 patients who provided a rectal swab; only 1 was cultured using non-chromogenic media. An additional 76 culture-negative rectal swabs were initially PCR positive, but none grew a carbapenem-resistant organism despite enrichment culture and only two were positive when retested several months later by Check-Direct and a second PCR assay (Cepheid GeneXpert® Carba-R). A modified Ct cut-off of <35 would have resolved these apparent false-positives. 40% of patients had a risk factor that should prompt screening and pre-emptive isolation as defined by UK CPE guidelines but only 8.1% and 20.2% of these patients had been screened and pre-emptively isolated by clinical teams, respectively. Overseas hospitalization was the only significant risk factor for CPE carriage (P < 0.001, OR 64.3, 95% CI 7.3-488.5). CONCLUSIONS: This study highlights a very low carriage rate of CPE. Hospitalization abroad is the most important risk factor to guide admission screening in this low-prevalence setting.

Phyo AP, Ashley EA, Anderson TJC, Carrara VI, Woodrow CJ, White NJ, Nosten F. 2016. Reply to Meshnick and Hastings et al. Clin Infect Dis, 63 (11), pp. 1528-1529. | Citations: 4 (Web of Science Lite) | Read more

Brown A, Halliday JS, Swadling L, Madden RG, Bendall R, Hunter JG, Maggs J, Simmonds P, Smith DB, Vine L et al. 2016. Characterization of the Specificity, Functionality, and Durability of Host T-Cell Responses Against the Full-Length Hepatitis E Virus. Hepatology, 64 (6), pp. 1934-1950. | Citations: 6 (Web of Science Lite) | Show Abstract | Read more

The interplay between host antiviral immunity and immunopathology during hepatitis E virus (HEV) infection determines important clinical outcomes. We characterized the specificity, functionality, and durability of host T-cell responses against the full-length HEV virus and assessed a novel "Quantiferon" assay for the rapid diagnosis of HEV infection. Eighty-nine volunteers were recruited from Oxford, Truro (UK), and Toulouse (France), including 44 immune-competent patients with acute HEV infection, 18 HEV-exposed immunosuppressed organ-transplant recipients (8 with chronic HEV), and 27 healthy volunteers. A genotype 3a peptide library (616 overlapping peptides spanning open reading frames [ORFs] 1-3) was used in interferon-gamma (IFN-γ) T-cell ELISpot assays. CD4+ /CD8+ T-cell subsets and polyfunctionality were defined using ICCS and SPICE analysis. Quantification of IFN-γ used whole-blood stimulation with recombinant HEV-capsid protein in the QuantiFERON kit. HEV-specific T-cell responses were detected in 41/44 immune-competent HEV exposed volunteers (median magnitude: 397 spot-forming units/106 peripheral blood mononuclear cells), most frequently targeting ORF2. High-magnitude, polyfunctional CD4 and CD8+ T cells were detected during acute disease and maintained to 12 years, but these declined over time, with CD8+ responses becoming more monofunctional. Low-level responses were detectable in immunosuppressed patients. Twenty-three novel HEV CD4+ and CD8+ T-cell targets were mapped predominantly to conserved genomic regions. QuantiFERON testing demonstrated an inverse correlation between IFN-γ production and the time from clinical presentation, providing 100% specificity, and 71% sensitivity (area under the receiver operator characteristic curve of 0.86) for HEV exposure at 0.3 IU/mL. CONCLUSION: Robust HEV-specific T-cell responses generated during acute disease predominantly target ORF2, but decline in magnitude and polyfunctionality over time. Defining HEV T-cell targets will be important for the investigation of HEV-associated autoimmune disease. (Hepatology 2016;64:1934-1950).

White NJ. 2016. Why Do Some Primate Malarias Relapse? Trends Parasitol, 32 (12), pp. 918-920. | Citations: 2 (Web of Science Lite) | Show Abstract | Read more

Relapse may have evolved in malaria as a mechanism to avoid suppression by more virulent species in mixed infections, thereby increasing transmission opportunities. Later evolution of long latency in Plasmodium vivax was a necessary adaptation as early hominins moved to colder areas with shorter mosquito breeding seasons. Genetic diversity was maintained through heterologous hypnozoite activation.

Phillips MA, White KL, Kokkonda S, Deng X, White J, El Mazouni F, Marsh K, Tomchick DR, Manjalanagara K, Rudra KR et al. 2016. A Triazolopyrimidine-Based Dihydroorotate Dehydrogenase Inhibitor with Improved Drug-like Properties for Treatment and Prevention of Malaria. ACS Infect Dis, 2 (12), pp. 945-957. | Citations: 7 (Web of Science Lite) | Show Abstract | Read more

The emergence of drug-resistant malaria parasites continues to hamper efforts to control this lethal disease. Dihydroorotate dehydrogenase has recently been validated as a new target for the treatment of malaria, and a selective inhibitor (DSM265) of the Plasmodium enzyme is currently in clinical development. With the goal of identifying a backup compound to DSM265, we explored replacement of the SF5-aniline moiety of DSM265 with a series of CF3-pyridinyls while maintaining the core triazolopyrimidine scaffold. This effort led to the identification of DSM421, which has improved solubility, lower intrinsic clearance, and increased plasma exposure after oral dosing compared to DSM265, while maintaining a long predicted human half-life. Its improved physical and chemical properties will allow it to be formulated more readily than DSM265. DSM421 showed excellent efficacy in the SCID mouse model of P. falciparum malaria that supports the prediction of a low human dose (<200 mg). Importantly DSM421 showed equal activity against both P. falciparum and P. vivax field isolates, while DSM265 was more active on P. falciparum. DSM421 has the potential to be developed as a single-dose cure or once-weekly chemopreventative for both P. falciparum and P. vivax malaria, leading to its advancement as a preclinical development candidate.

Ravinetto R, De Weggheleire A, Dorlo TPC, Francque S, Sokkab A, Pouget C, Meessen B, Tabernero P, Newton PN, Lynen L. 2016. Predictable threats to public health through delaying universal access to innovative medicines for hepatitis C: a pharmaceutical standpoint. Trop Med Int Health, 21 (12), pp. 1490-1495. | Citations: 2 (Web of Science Lite) | Read more

Hantrakun V, Rongkard P, Oyuchua M, Amornchai P, Lim C, Wuthiekanun V, Day NPJ, Peacock SJ, Limmathurotsakul D. 2016. Soil Nutrient Depletion Is Associated with the Presence of Burkholderia pseudomallei. Appl Environ Microbiol, 82 (24), pp. 7086-7092. | Citations: 5 (Scopus) | Show Abstract | Read more

Burkholderia pseudomallei is a soil-dwelling bacterium and the cause of melioidosis, which kills an estimated 89,000 people per year worldwide. Agricultural workers are at high risk of infection due to repeated exposure to the bacterium. Little is known about the soil physicochemical properties associated with the presence or absence of the organism. Here, we evaluated the soil physicochemical properties and presence of B. pseudomallei in 6,100 soil samples collected from 61 rice fields in Thailand. The presence of B. pseudomallei was negatively associated with the proportion of clay, proportion of moisture, level of salinity, percentage of organic matter, presence of cadmium, and nutrient levels (phosphorus, potassium, calcium, magnesium, and iron). The presence of B. pseudomallei was not associated with the level of soil acidity (P = 0.54). In a multivariable logistic regression model, the presence of B. pseudomallei was negatively associated with the percentage of organic matter (odds ratio [OR], 0.06; 95% confidence interval [CI], 0.01 to 0.47; P = 0.007), level of salinity (OR, 0.06; 95% CI, 0.01 to 0.74; P = 0.03), and percentage of soil moisture (OR, 0.81; 95% CI, 0.66 to 1.00; P = 0.05). Our study suggests that B. pseudomallei thrives in rice fields that are nutrient depleted. Some agricultural practices result in a decline in soil nutrients, which may impact the presence and amount of B. pseudomallei bacteria in affected areas. IMPORTANCE: Burkholderia pseudomallei is an environmental Gram-negative bacillus and the cause of melioidosis. Humans acquire the disease following skin inoculation, inhalation, or ingestion of the bacterium in the environment. The presence of B. pseudomallei in soil defines geographic regions where humans and livestock are at risk of melioidosis, yet little is known about the soil properties associated with the presence of the organism. We evaluated the soil properties and presence of B. pseudomallei in 61 rice fields in East, Central, and Northeast Thailand. We demonstrated that the organism was more commonly found in soils with lower levels of organic matter and nutrients, including phosphorus, potassium, calcium, magnesium, and iron. We also demonstrated that crop residue burning after harvest, which can reduce soil nutrients, was not uncommon. Some agricultural practices result in a decline in soil nutrients, which may impact the presence and amount of B. pseudomallei bacteria in affected areas.

Thwaites CL, Lundeg G, Dondorp AM, sepsis in resource-limited settings–expert consensus recommendations group* of the European Society of Intensive Care Medicine (ESICM) and the Mahidol-Oxford Research Unit (MORU) in Bangkok, Thailand. 2016. Infection management in patients with sepsis and septic shock in resource-limited settings. Intensive Care Med, 42 (12), pp. 2117-2118. | Citations: 1 (Web of Science Lite) | Read more

Thuong NTT, Tram TTB, Dinh TD, Thai PVK, Heemskerk D, Bang ND, Chau TTH, Russell DG, Thwaites GE, Hawn TR et al. 2016. MARCO variants are associated with phagocytosis, pulmonary tuberculosis susceptibility and Beijing lineage. Genes Immun, 17 (7), pp. 419-425. | Citations: 3 (Scopus) | Show Abstract | Read more

Macrophage receptor with collagenous structure (MARCO) has an important role in the phagocytosis of Mycobacterium tuberculosis (M. tuberculosis). We hypothesized that MARCO polymorphisms are associated with phagocytosis, tuberculosis (TB) disease susceptibility and presentation, and infecting lineage. We used a human cellular model to examine how MARCO genotype mediates the immune response; a case-control study to investigate tuberculosis host genetic susceptibility; and a host-pathogen genetic analysis to study host-pathogen interactions. Two MARCO heterozygous (AG) genotypes (single-nucleotide polymorphisms rs2278589 and rs6751745) were associated with impaired phagocytosis of M. tuberculosis trehalose 6,6'-dimycolate-cord factor and β-glucan-coated beads in macrophages. The heterozygous genotypes of rs2278589 and rs6751745 were also associated with increased risk of pulmonary TB (PTB; rs2278589, P=0.001, odds ratio (OR)=1.6; rs6751745, P=0.009, OR=1.4), and with severe chest X-ray abnormalities (P=0.007, OR=1.6). These two genotypes were also associated with the Beijing lineage (rs2278589, P=0.001, OR=1.7; rs6751745, P=0.01, OR=1.5). Together, these results suggest that MARCO polymorphisms may regulate phagocytosis of M. tuberculosis and susceptibility and severity of PTB. They also suggest MARCO genotype and Beijing strains may interact to increase the risk of PTB.

Rongkard P, Hantrakun V, Dittrich S, Srilohasin P, Amornchai P, Langla S, Lim C, Day NPJ, AuCoin D, Wuthiekanun V, Limmathurotsakul D. 2016. Utility of a Lateral Flow Immunoassay (LFI) to Detect Burkholderia pseudomallei in Soil Samples. PLoS Negl Trop Dis, 10 (12), pp. e0005204. | Show Abstract | Read more

BACKGROUND: Culture is the gold standard for the detection of environmental B. pseudomallei. In general, soil specimens are cultured in enrichment broth for 2 days, and then the culture broth is streaked on an agar plate and incubated further for 7 days. However, identifying B. pseudomallei on the agar plates among other soil microbes requires expertise and experience. Here, we evaluate a lateral flow immunoassay (LFI) developed to detect B. pseudomallei capsular polysaccharide (CPS) in clinical samples as a tool to detect B. pseudomallei in environmental samples. METHODOLOGY/PRINCIPAL FINDINGS: First, we determined the limit of detection (LOD) of LFI for enrichment broth of the soil specimens. Soil specimens (10 grams/specimen) culture negative for B. pseudomallei were spiked with B. pseudomallei ranging from 10 to 105 CFU, and incubated in 10 ml of enrichment broth in air at 40°C. Then, on day 2, 4 and 7 of incubation, 50 μL of the upper layer of the broth were tested on the LFI, and colony counts to determine quantity of B. pseudomallei in the broth were performed. We found that all five soil specimens inoculated at 10 CFU were negative by LFI on day 2, but four of those five specimens were LFI positive on day 7. The LOD of the LFI was estimated to be roughly 3.8x106 CFU/ml, and culture broth on day 7 was selected as the optimal sample for LFI testing. Second, we evaluated the utility of the LFI by testing 105 soil samples from Northeast Thailand. All samples were also tested by standard culture and quantitative PCR (qPCR) targeting orf2. Of 105 soil samples, 35 (33%) were LFI positive, 25 (24%) were culture positive for B. pseudomallei, and 79 (75%) were qPCR positive. Of 11 LFI positive but standard culture negative specimens, six were confirmed by having the enrichment broth on day 7 culture positive for B. pseudomallei, and an additional three by qPCR. The LFI had 97% (30/31) sensitivity to detect soil specimens culture positive for B. pseudomallei. CONCLUSIONS/SIGNIFICANCE: The LFI can be used to detect B. pseudomallei in soil samples, and to select which samples should be sent to reference laboratories or proceed further for bacterial isolation and confirmation. This could considerably decrease laboratory workload and assist the development of a risk map for melioidosis in resource-limited settings.

Ngoi CN, Siqueira J, Li L, Deng X, Mugo P, Graham SM, Price MA, Sanders EJ, Delwart E. 2016. The plasma virome of febrile adult Kenyans shows frequent parvovirus B19 infections and a novel arbovirus (Kadipiro virus). J Gen Virol, 97 (12), pp. 3359-3367. | Citations: 2 (Web of Science Lite) | Show Abstract | Read more

Viral nucleic acids present in the plasma of 498 Kenyan adults with unexplained fever were characterized by metagenomics analysis of 51 sample pools. The highest to lowest fraction of plasma pools was positive for parvovirus B19 (75 %), pegivirus C (GBV-C) (67 %), alpha anellovirus (59 %), gamma anellovirus (55 %), beta anellovirus (41 %), dengue virus genotype 2 (DENV-2) (16 %), human immunodeficiency virus type 1 (6 %), human herpesvirus 6 (6 %), HBV (4 %), rotavirus (4 %), hepatitis B virus (4 %), rhinovirus C (2 %), Merkel cell polyomavirus (MCPyV; 2 %) and Kadipiro virus (2 %). Ranking by overall percentage of viral reads yielded similar results. Characterization of viral nucleic acids in the plasma of a febrile East African population showed a high frequency of parvovirus B19 and DENV infections and detected a reovirus (Kadipiro virus) previously reported only in Asian Culex mosquitoes, providing a baseline to compare with future virome studies to detect emerging viruses in this region.

Lim R, Peto TJ, Tripura R, Cheah PY. 2016. Village Drama Against Malaria. Lancet, 388 (10063), pp. 2990. | Citations: 3 (Scopus) | Read more

Hoang Quoc C, Henrik S, Isabel R-B, In-Kyu Y, Chau NVV, Hung NT, Tuan HM, Lan PT, Willis B, Nisalak A et al. 2016. Synchrony of Dengue Incidence in Ho Chi Minh City and Bangkok. PLoS Negl Trop Dis, 10 (12), pp. e0005188. | Citations: 1 (Scopus) | Show Abstract | Read more

BACKGROUND: Ho Chi Minh City and Bangkok are highly dengue endemic. The extent to which disease patterns are attributable to local versus regional dynamics remains unclear. To address this gap we compared key transmission parameters across the locations. METHODS AND PRINCIPAL FINDINGS: We used 2003-2009 age-stratified case data to inform catalytic transmission models. Further, we compared the spatial clustering of serotypes within each city. We found that annual case numbers were highly consistent across the two cities (correlation of 0.77, 95% CI: 0.74-0.79) as was the annual force of infection (correlation of 0.57, 95% CI: 0.46-0.68). Serotypes were less similar with serotype-specific correlations ranging from 0.65 for DENV1 to -0.14 for DENV4. Significant spatial clustering of serotypes was observed in HCMC at distances <500m, similar to previous observations from Bangkok. DISCUSSIONS: Dengue dynamics are comparable across these two hubs. Low correlation in serotype distribution suggests that similar built environments, vector populations and climate, rather than viral flow drives these observations.

de Vries EMG, Wang J, Leeflang MMG, Boonstra K, Weersma RK, Beuers UH, Geskus RB, Ponsioen CY. 2016. Alkaline phosphatase at diagnosis of primary sclerosing cholangitis and 1 year later: evaluation of prognostic value. Liver Int, 36 (12), pp. 1867-1875. | Citations: 8 (Scopus) | Show Abstract | Read more

BACKGROUND: Primary sclerosing cholangitis (PSC) is a slowly progressive liver disease. Reliable biomarkers to predict outcome are urgently needed to serve as surrogate endpoints and/or stratifiers in clinical trials. Reduction in serum alkaline phosphatase (ALP) has been proposed as prognostic surrogate marker in PSC. The aim of this study was to asses if ALP at diagnosis (T0), 1 year later (T1), and percentage change between both time points hold prognostic value, and to determine the optimal threshold. METHODS: We retrospectively collected ALP levels at T0 and T1 for patients included in a large PSC cohort. The association of ALP at T0, T1, and percentage change with the combined endpoint (PSC-related death, liver transplantation) was analysed. Predictive value was determined using C-statistics. RESULTS: A total of 366 patients were included, of whom 66 (18%) reached an endpoint: 26 (7%) PSC-related death, 40 (11%) liver transplantation. At T0 and T1, 84% used ursodeoxycholic acid. A positive association was observed between level of ALP at T0 and T1 and the hazard of reaching an endpoint, up to values around 2.5 times upper limit of normal (xULN). A larger decrease in ALP between T0 and T1 decreased the event rate. A range of thresholds (0.5-3×ULN) with about similar C-statistics was found. In this cohort, the optimal threshold was 1.3×ULN at T1. CONCLUSION: ALP can be used to discriminate between PSC patients with a good and a poor prognosis. These findings indicate that ALP can serve as stratifier, and potentially as surrogate endpoint for clinical trials in PSC.

Barger-Kamate B, Deloria Knoll M, Kagucia EW, Prosperi C, Baggett HC, Brooks WA, Feikin DR, Hammitt LL, Howie SRC, Levine OS et al. 2016. Pertussis-Associated Pneumonia in Infants and Children From Low- and Middle-Income Countries Participating in the PERCH Study. Clin Infect Dis, 63 (suppl 4), pp. S187-S196. | Citations: 5 (Scopus) | Show Abstract | Read more

BACKGROUND:  Few data exist describing pertussis epidemiology among infants and children in low- and middle-income countries to guide preventive strategies. METHODS:  Children 1-59 months of age hospitalized with World Health Organization-defined severe or very severe pneumonia in 7 African and Asian countries and similarly aged community controls were enrolled in the Pneumonia Etiology Research for Child Health study. They underwent a standardized clinical evaluation and provided nasopharyngeal and oropharyngeal swabs and induced sputum (cases only) for Bordetella pertussis polymerase chain reaction. Risk factors and pertussis-associated clinical findings were identified. RESULTS:  Bordetella pertussis was detected in 53 of 4200 (1.3%) cases and 11 of 5196 (0.2%) controls. In the age stratum 1-5 months, 40 (2.3% of 1721) cases were positive, all from African sites, as were 8 (0.5% of 1617) controls. Pertussis-positive African cases 1-5 months old, compared to controls, were more often human immunodeficiency virus (HIV) uninfected-exposed (adjusted odds ratio [aOR], 2.2), unvaccinated (aOR, 3.7), underweight (aOR, 6.3), and too young to be immunized (aOR, 16.1) (all P ≤ .05). Compared with pertussis-negative African cases in this age group, pertussis-positive cases were younger, more likely to vomit (aOR, 2.6), to cough ≥14 days (aOR, 6.3), to have leukocyte counts >20 000 cells/µL (aOR, 4.6), and to have lymphocyte counts >10 000 cells/µL (aOR, 7.2) (all P ≤ .05). The case fatality ratio of pertussis-infected pneumonia cases 1-5 months of age was 12.5% (95% confidence interval, 4.2%-26.8%; 5/40); pertussis was identified in 3.7% of 137 in-hospital deaths among African cases in this age group. CONCLUSIONS:  In the postneonatal period, pertussis causes a small fraction of hospitalized pneumonia cases and deaths; however, case fatality is substantial. The propensity to infect unvaccinated infants and those at risk for insufficient immunity (too young to be vaccinated, premature, HIV-infected/exposed) suggests that the role for maternal vaccination should be considered along with efforts to reduce exposure to risk factors and to optimize childhood pertussis vaccination coverage.

Hamers RL, Paredes R. 2016. Next-generation sequencing and HIV drug resistance surveillance The Lancet HIV, 3 (12), pp. e553-e554. | Read more

Hanboonkunupakarn B, White NJ. 2016. The threat of artemisinin resistant malaria in Southeast Asia. Travel Med Infect Dis, 14 (6), pp. 548-550. | Citations: 1 (Scopus) | Read more

Parker DM, Landier J, von Seidlein L, Dondorp A, White L, Hanboonkunupakarn B, Maude RJ, Nosten FH. 2016. Limitations of malaria reactive case detection in an area of low and unstable transmission on the Myanmar-Thailand border. Malar J, 15 (1), pp. 571. | Citations: 4 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Reactive case detection is an approach that has been proposed as a tool for malaria elimination in low-transmission settings. It is an intuitively justified approach based on the concept of space-time clustering of malaria cases. When an index malaria clinical case is detected, it triggers reactive screening and treatment in the index house and neighbouring houses. However, the efficacy of this approach at varying screening radii and malaria prevalence remains ill defined. METHODS: Data were obtained from a detailed demographic and geographic surveillance study in four villages on the Myanmar-Thailand border. Clinical cases were recorded at village malaria clinics and were linked back to patients' residencies. These data were used to simulate the efficacy of reactive case detection for clinical cases using rapid diagnostic tests (RDT). Simulations took clinical cases in a given month and tabulated the number of cases that would have been detected in the following month at varying screening radii around the index houses. Simulations were run independently for both falciparum and vivax malaria. Each simulation of a reactive case detection effort was run in comparison with a strategy using random selection of houses for screening. RESULTS: In approximately half of the screenings for falciparum and 10% for vivax it would have been impossible to detect any malaria cases regardless of the screening strategy because the screening would have occurred during times when there were no cases. When geographically linked cases were present in the simulation, reactive case detection would have only been successful at detecting most malaria cases using larger screening radii (150-m radius and above). At this screening radius and above, reactive case detection does not perform better than random screening of an equal number of houses in the village. Screening within very small radii detects only a very small proportion of cases, but despite this low performance is better than random screening with the same sample size. CONCLUSIONS: The results of these simulations indicate that reactive case detection for clinical cases using RDTs has limited ability in halting transmission in regions of low and unstable transmission. This is linked to high spatial heterogeneity of cases, acquisition of malaria infections outside the village, as well missing asymptomatic infections. When cases are few and sporadic, reactive case detection would result in major time and budgetary losses.

Wuthiekanun V, White NJ, Amornchai P, Day NPJ, Limmathurotsakul D. 2016. Quality controls for antimicrobial disk diffusion testing on Leptospira Vanaporn Wuthiekanun agar. Trans R Soc Trop Med Hyg, 110 (11), pp. 673-675. | Read more

Turner P, Kloprogge S, Miliya T, Soeng S, Tan P, Sar P, Yos P, Moore CE, Wuthiekanun V, Limmathurotsakul D et al. 2016. A retrospective analysis of melioidosis in Cambodian children, 2009-2013. BMC Infect Dis, 16 (1), pp. 688. | Citations: 2 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Melioidiosis, infection by Burkholderia pseudomallei, is an important but frequently under-recognised cause of morbidity and mortality in Southeast Asia and elsewhere in the tropics. Data on the epidemiology of paediatric melioidosis in Cambodia are extremely limited. METHODS: Culture-positive melioidosis cases presenting to Angkor Hospital for Children, a non-governmental paediatric hospital located in Siem Reap, Northern Cambodia, between 1st January 2009 and 31st December 2013 were identified by searches of hospital and laboratory databases and logbooks. RESULTS: One hundred seventy-three evaluable cases were identified, presenting from eight provinces. For Siem Reap province, the median commune level incidence was estimated to be 28-35 cases per 100,000 children <15 years per year. Most cases presented during the wet season, May to October. The median age at presentation was 5.7 years (range 8 days-15.9 years). Apart from undernutrition, co-morbidities were rare. Three quarters (131/173) of the children had localised infection, most commonly skin/soft tissue infection (60 cases) or suppurative parotitis (51 cases). There were 39 children with B. pseudomallei bacteraemia: 29 (74.4%) of these had clinical and/or radiological evidence of pneumonia. Overall mortality was 16.8% (29/173) with mortality in bacteraemic cases of 71.8% (28/39). At least seven children did not receive an antimicrobial with activity against B. pseudomallei prior to death. CONCLUSIONS: This retrospective study demonstrated a considerable burden of melioidosis in Cambodian children. Given the high mortality associated with bacteraemic infection, there is an urgent need for greater awareness amongst healthcare professionals in Cambodia and other countries where melioidosis is known or suspected to be endemic. Empiric treatment guidelines should ensure suspected cases are treated early with appropriate antimicrobials.

Hendrickx S, Guerin PJ, Caljon G, Croft SL, Maes L. 2016. Evaluating drug resistance in visceral leishmaniasis: the challenges. Parasitology, pp. 1-11. | Show Abstract | Read more

For decades antimonials were the drugs of choice for the treatment of visceral leishmaniasis (VL), but the recent emergence of resistance has made them redundant as first-line therapy in the endemic VL region in the Indian subcontinent. The application of other drugs has been limited due to adverse effects, perceived high cost, need for parenteral administration and increasing rate of treatment failures. Liposomal amphotericin B (AmB) and miltefosine (MIL) have been positioned as the effective first-line treatments; however, the number of monotherapy MIL-failures has increased after a decade of use. Since no validated molecular resistance markers are yet available, monitoring and surveillance of changes in drug sensitivity and resistance still depends on standard phenotypic in vitro promastigote or amastigote susceptibility assays. Clinical isolates displaying defined MIL- or AmB-resistance are still fairly scarce and fundamental and applied research on resistance mechanisms and dynamics remains largely dependent on laboratory-generated drug resistant strains. This review addresses the various challenges associated with drug susceptibility and -resistance monitoring in VL, with particular emphasis on the choice of strains, susceptibility model selection and standardization of procedures with specific read-out parameters and well-defined threshold criteria. The latter are essential to support surveillance systems and safeguard the limited number of currently available antileishmanial drugs.

Mbevi G, Ayieko P, Irimu G, Akech S, English M, Clinical Information Network authors. 2016. Prevalence, aetiology, treatment and outcomes of shock in children admitted to Kenyan hospitals. BMC Med, 14 (1), pp. 184. | Citations: 1 (Scopus) | Show Abstract | Read more

BACKGROUND: Shock may complicate several acute childhood illnesses in hospitals within low-income countries and has a high case fatality. Hypovolemic shock secondary to diarrhoea/dehydration and septic shock are thought to be common, but there are few reliable data on prevalence or treatment that differ for the two major forms of shock. Examining prevalence and treatment practices has become important since reports suggest high risks from liberal use of fluid boluses in African children. The present study aims to estimate the prevalence, fluid management practices and outcomes of shock among hospitalised children. METHODS: We analysed paediatric in-patient data collected using discharge case record review between October 2013 and February 2016 from 14 hospitals in Kenya which are part of a network (referred to as the Clinical Information Network) using similar tools for standardised clinical records with care directed by the local clinical team leaders. Data are from a period after dissemination of national guidance seeking to limit use of bolus fluids. RESULTS: A total of 74,402 children were admitted between October 2013 and February 2016. Children aged < 30 days or > 5 years, with severe acute malnutrition, surgical/burns, or cases with pre-defined minimum data sets were excluded from analysis. This resulted in 42,937 patients meeting the inclusion criteria. Prevalence of clinically diagnosed shock was 1.5 % (n = 622) and overall bolus use was 0.9 % (n = 366); 41 % (256/622) of children with clinically diagnosed shock did not receive a fluid bolus (but had a fluid plan for management of dehydration). Identified cases appeared mostly to be hypovolaemic shock secondary to dehydration/diarrhoea (94 %, 582/622), with a high case fatality (34 %, 211/622). Overall mortality for all admitted children was 5 % (2115/42,937) and was 7.9 % (798/10,096) in children with dehydration/diarrhoea. The diagnosis of hypovolaemic shock was nearly always accompanied by additional clinical diagnosis (99 %), most often pneumonia or malaria. Where bolus fluids were used, they were prescribed in accordance with guidelines (isotonic fluid at correct volume) in 92 % of cases. Inappropriate use of bolus fluids to treat milder forms of impaired circulation appeared very rarely. CONCLUSION: A diagnosis of shock is uncommon at admission and use of fluid bolus is rare in admissions to Kenyan hospitals. A fluid bolus, when prescribed, is mostly used in children with hypovolemic shock secondary to dehydration and case fatality in these cases is high. We found little evidence of liberal use of fluid bolus that might cause harm in a period following dissemination of national guidelines suggesting very strict criteria for fluid bolus use.

Nyiro JU, Sande CJ, Mutunga M, Kiyuka PK, Munywoki PK, Scott JAG, Nokes DJ. 2016. Absence of Association between Cord Specific Antibody Levels and Severe Respiratory Syncytial Virus (RSV) Disease in Early Infants: A Case Control Study from Coastal Kenya. PLoS One, 11 (11), pp. e0166706. | Citations: 4 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: The target group for severe respiratory syncytial virus (RSV) disease prevention is infants under 6 months of age. Vaccine boosting of antibody titres in pregnant mothers could protect these young infants from severe respiratory syncytial virus (RSV) associated disease. Quantifying protective levels of RSV-specific maternal antibody at birth would inform vaccine development. METHODS: A case control study nested in a birth cohort (2002-07) was conducted in Kilifi, Kenya; where 30 hospitalised cases of RSV-associated severe disease were matched to 60 controls. Participants had a cord blood and 2 subsequent 3-monthly blood samples assayed for RSV-specific neutralising antibody by the plaque reduction neutralisation test (PRNT). Two sample paired t test and conditional logistic regression were used in analyses of log2PRNT titres. RESULTS: The mean RSV log2PRNT titre at birth for cases and controls were not significantly different (P = 0.4) and remained so on age-stratification. Cord blood PRNT titres showed considerable overlap between cases and controls. The odds of RSV disease decreased with increase in log2PRNT cord blood titre. There was a 30% reduction in RSV disease per unit increase in log2PRNT titre (<3months age group) but not significant (P = 0.3). CONCLUSIONS: From this study, there is no strong evidence of protection by maternal RSV specific antibodies from severe RSV disease. Cord antibody levels show wide variation with considerable overlap between cases and controls. It is likely that, there are additional factors to specific PRNT antibody levels which determine susceptibility to severe RSV disease. In addition, higher levels of neutralizing antibody beyond the normal range may be required for protection; which it is hoped can be achieved by a maternal RSV vaccine.

Thanh TT, Van HMT, Hong NTT, Nhu LNT, Anh NT, Tuan HM, Hien HV, Tuong NM, Kien TT, Khanh TH et al. 2016. The first genome sequences of human bocaviruses from Vietnam. Wellcome Open Res, 1 pp. 16. | Show Abstract | Read more

As part of an ongoing effort to generate complete genome sequences of hand, foot and mouth disease-causing enteroviruses directly from clinical specimens, two complete coding sequences and two partial genomic sequences of human bocavirus 1 (n=3) and 2 (n=1) were co-amplified and sequenced, representing the first genome sequences of human bocaviruses from Vietnam. The sequences may aid future study aiming at understanding the evolution of the pathogen.

Prentice HA, Lu H, Price MA, Kamali A, Karita E, Lakhi S, Sanders EJ, Anzala O, Allen S, Goepfert PA et al. 2016. Dynamics and Correlates of CD8 T-Cell Counts in Africans with Primary Human Immunodeficiency Virus Type 1 Infection. J Virol, 90 (22), pp. 10423-10430. | Show Abstract | Read more

In individuals with HIV-1 infection, depletion of CD4+ T cells is often accompanied by a malfunction of CD8+ T cells that are persistently activated and/or exhausted. While the dynamics and correlates of CD4 counts have been well documented, the same does not apply to CD8 counts. Here, we examined the CD8 counts in a cohort of 497 Africans with primary HIV-1 infection evaluated in monthly to quarterly follow-up visits for up to 3 years in the absence of antiretroviral therapy. Statistical models revealed that (i) CD8 counts were relatively steady in the 3- to 36-month period of infection and similar between men and women; (ii) neither geography nor heterogeneity in the HIV-1 set-point viral load could account for the roughly 10-fold range of CD8 counts in the cohort (P > 0.25 in all tests); and (iii) factors independently associated with relatively high CD8 counts included demographics (age ≤ 40 years, adjusted P = 0.010) and several human leukocyte antigen class I (HLA-I) alleles, including HLA-A*03:01 (P = 0.013), B*15:10 (P = 0.007), and B*58:02 (P < 0.001). Multiple sensitivity analyses provided supporting evidence for these novel relationships. Overall, these findings suggest that factors associated with the CD8 count have little overlap with those previously reported for other HIV-1-related outcome measures, including viral load, CD4 count, and CD4/CD8 ratio. IMPORTANCE: Longitudinal data from 497 HIV-1 seroconverters allowed us to systematically evaluate the dynamics and correlates of CD8+ T-cell counts during untreated primary HIV-1 infection in eastern and southern Africans. Our findings suggest that individuals with certain HLA-I alleles, including A*03 (exclusively A*03:01), persistently maintain relatively high CD8 counts following HIV-1 infection, a finding which may offer an intriguing explanation for the recently reported, negative association of A*03 with HIV-1-specific, broadly neutralizing antibody responses. In future studies, attention to HLA-I genotyping data may benefit in-depth understanding of both cellular and humoral immunity, as well as the intrinsic balances of these types of immunity, especially in settings where there is emerging evidence of antagonism between the two arms of adaptive immunity.

Auburn S, Böhme U, Steinbiss S, Trimarsanto H, Hostetler J, Sanders M, Gao Q, Nosten F, Newbold CI, Berriman M et al. 2016. A new Plasmodium vivax reference sequence with improved assembly of the subtelomeres reveals an abundance of pir genes. Wellcome Open Res, 1 pp. 4. | Citations: 6 (Scopus) | Show Abstract | Read more

Plasmodium vivax is now the predominant cause of malaria in the Asia-Pacific, South America and Horn of Africa. Laboratory studies of this species are constrained by the inability to maintain the parasite in continuous ex vivo culture, but genomic approaches provide an alternative and complementary avenue to investigate the parasite's biology and epidemiology. To date, molecular studies of P. vivax have relied on the Salvador-I reference genome sequence, derived from a monkey-adapted strain from South America. However, the Salvador-I reference remains highly fragmented with over 2500 unassembled scaffolds.  Using high-depth Illumina sequence data, we assembled and annotated a new reference sequence, PvP01, sourced directly from a patient from Papua Indonesia. Draft assemblies of isolates from China (PvC01) and Thailand (PvT01) were also prepared for comparative purposes. The quality of the PvP01 assembly is improved greatly over Salvador-I, with fragmentation reduced to 226 scaffolds. Detailed manual curation has ensured highly comprehensive annotation, with functions attributed to 58% core genes in PvP01 versus 38% in Salvador-I. The assemblies of PvP01, PvC01 and PvT01 are larger than that of Salvador-I (28-30 versus 27 Mb), owing to improved assembly of the subtelomeres.  An extensive repertoire of over 1200 Plasmodium interspersed repeat (pir) genes were identified in PvP01 compared to 346 in Salvador-I, suggesting a vital role in parasite survival or development. The manually curated PvP01 reference and PvC01 and PvT01 draft assemblies are important new resources to study vivax malaria. PvP01 is maintained at GeneDB and ongoing curation will ensure continual improvements in assembly and annotation quality.

Alshahrani AM, Abdelgader TM, Saeed I, Al-Akhshami A, Al-Ghamdi M, Al-Zahrani MH, El Hassan I, Kyalo D, Snow RW. 2016. The changing malaria landscape in Aseer region, Kingdom of Saudi Arabia: 2000-2015. Malar J, 15 (1), pp. 538. | Show Abstract | Read more

BACKGROUND: In 2004, a revised action plan was developed, supported by the World Health Organization, to eliminate malaria from Saudi Arabia by preventing re-introduction of malaria into regions since declared malaria free, eliminating foci of transmission in the Mecca and Medina areas and a concerted effort of foci surveillance and control, to eliminate malaria from the regions of Jazan and Aseer. This paper provides the context, activities, progress, and possible contributions toward malaria elimination in the Aseer region since 2000, with a more detailed analysis of the spatial location of locally acquired case incidence since 2012. METHODS: This is a descriptive study of all available Ministry of Health surveillance data and process reports since 2000, with higher spatial resolution analysis of data between 2012 and 2015. RESULTS: In 2000, there were 511 cases of Plasmodium falciparum locally acquired infection. The following 4 years witnessed a dramatic decline in cases to only 18 locally acquired infections reported in 2005. A resurgence in local infections was reported in 2006 (93) and 2007 (165), thereafter (2008-2014) local cases continued to decline to fewer than 40 per year across the region. However, in 2015, a small rise was noted (51). All locally acquired infections were P. falciparum. There has been a constant flow of imported infections into Aseer since 2000, mostly among immigrant labour from Pakistan, India, Sudan, and Yemen. Imported infections have included both Plasmodium vivax and P. falciparum. The spatial extent of malaria appears to be changing, but there remain two intractable areas Sarat Abeda and Dhran Aljanub, where risks per reporting centre have changed little since 2001, remaining above 0.5 per 10,000 population. Only seven villages contributed 55% of all locally acquired infection since 2012. DISCUSSION: Aseer has reached a state of very low incidence of locally acquired infections, despite a constant source of imported infections from outside the country. How many of the local infections are F2 generations from imported infections or how many are a result of residual active transmission between asymptomatic carriers of infections transmitted by pockets of existing Anopheles arabiensis populations remains unknown. A more detailed investigation of the spatial and temporal patterns of infected hosts, parasites and vectors would help define whether this region has managed to effectively prevent local transmission of new infections.

Chaguza C, Cornick JE, Harris SR, Andam CP, Bricio-Moreno L, Yang M, Yalcin F, Ousmane S, Govindpersad S, Senghore M et al. 2016. Understanding pneumococcal serotype 1 biology through population genomic analysis. BMC Infect Dis, 16 (1), pp. 649. | Citations: 1 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Pneumococcus kills over one million children annually and over 90 % of these deaths occur in low-income countries especially in Sub-Saharan Africa (SSA) where HIV exacerbates the disease burden. In SSA, serotype 1 pneumococci particularly the endemic ST217 clone, causes majority of the pneumococcal disease burden. To understand the evolution of the virulent ST217 clone, we analysed ST217 whole genomes from isolates sampled from African and Asian countries. METHODS: We analysed 226 whole genome sequences from the ST217 lineage sampled from 9 African and 4 Asian countries. We constructed a whole genome alignment and used it for phylogenetic and coalescent analyses. We also screened the genomes to determine presence of antibiotic resistance conferring genes. RESULTS: Population structure analysis grouped the ST217 isolates into five sequence clusters (SCs), which were highly associated with different geographical regions and showed limited intracontinental and intercontinental spread. The SCs showed lower than expected genomic sequence, which suggested strong purifying selection and small population sizes caused by bottlenecks. Recombination rates varied between the SCs but were lower than in other successful clones such as PMEN1. African isolates showed higher prevalence of antibiotic resistance genes than Asian isolates. Interestingly, certain West African isolates harbored a defective chloramphenicol and tetracycline resistance-conferring element (Tn5253) with a deletion in the loci encoding the chloramphenicol resistance gene (cat pC194), which caused lower chloramphenicol than tetracycline resistance. Furthermore, certain genes that promote colonisation were absent in the isolates, which may contribute to serotype 1's rarity in carriage and consequently its lower recombination rates. CONCLUSIONS: The high phylogeographic diversity of the ST217 clone shows that this clone has been in circulation globally for a long time, which allowed its diversification and adaptation in different geographical regions. Such geographic adaptation reflects local variations in selection pressures in different locales. Further studies will be required to fully understand the biological mechanisms which makes the ST217 clone highly invasive but unable to successfully colonise the human nasopharynx for long durations which results in lower recombination rates.

Karyana M, Devine A, Kenangalem E, Burdarm L, Poespoprodjo JR, Vemuri R, Anstey NM, Tjitra E, Price RN, Yeung S. 2016. Treatment-seeking behaviour and associated costs for malaria in Papua, Indonesia. Malar J, 15 (1), pp. 536. | Citations: 1 (Scopus) | Show Abstract | Read more

BACKGROUND: Malaria remains a significant public health issue in Eastern Indonesia, where multidrug resistant Plasmodium falciparum and Plasmodium vivax are highly prevalent. The objective of this study was to describe treatment-seeking behaviour and household costs prior to a change to a unified treatment policy of dihydroartemisinin-piperaquine in Mimika district, Papua province in 2006. METHODS: In 2005 a randomized cross-sectional household survey was conducted to collect data on demographics, socio-economic status (SES), treatment-seeking, case management, and household costs. Information on the cost of illness was also collected from patients exiting health facilities, in order to compare the cost of episodes diagnosed as P. vivax compared with those diagnosed as P. falciparum. RESULTS: 825 households were included in the survey. Of the 764 individuals who sought treatment for fever outside the home in the last month, 46% (349/764) went to a public health facility. Of the 894 reported visits to healthcare providers, 48% (433) resulted in a blood test, of which 78% (337) were reportedly positive. Only 10% (17/177) of individuals who reported testing positive for P. falciparum or mixed infection received the first-line treatment of chloroquine with SP, and 38% (61/159) of those with a diagnosis of P. vivax reportedly received the first-line treatment of chloroquine and primaquine. Overall, public facilities were more likely to prescribe the correct prevailing first-line drug combinations than private providers (OR = 3.77 [95% CI 2.31-6.14], p < 0.001). The mean cost to the household of an episode of P. vivax was similar to the cost of P. falciparum [US$44.50 (SD: 46.23) vs US$48.58 (SD: 64.65)]. CONCLUSIONS: Private providers were a popular source of treatment for malaria, but adherence to the national guidelines was low and the economic burden of malaria for both P. falciparum and P. vivax infections was substantial. Engagement with the private sector is needed to ensure that patients have access to affordable good quality, effective diagnostics and anti-malarials for both P. falciparum and P. vivax.

Srimuang K, Miotto O, Lim P, Fairhurst RM, Kwiatkowski DP, Woodrow CJ, Imwong M, Tracking Resistance to Artemisinin Collaboration. 2016. Analysis of anti-malarial resistance markers in pfmdr1 and pfcrt across Southeast Asia in the Tracking Resistance to Artemisinin Collaboration. Malar J, 15 (1), pp. 541. | Citations: 3 (Scopus) | Show Abstract | Read more

BACKGROUND: Declining anti-malarial efficacy of artemisinin-based combination therapy, and reduced Plasmodium falciparum susceptibility to individual anti-malarials are being documented across an expanding area of Southeast Asia (SEA). Genotypic markers complement phenotypic studies in assessing the efficacy of individual anti-malarials. METHODS: The markers pfmdr1 and pfcrt were genotyped in parasite samples obtained in 2011-2014 at 14 TRAC (Tracking Resistance to Artemisinin Collaboration) sites in mainland Southeast Asia using a combination of PCR and next-generation sequencing methods. RESULTS: Pfmdr1 amplification, a marker of mefloquine and lumefantrine resistance, was highly prevalent at Mae Sot on the Thailand-Myanmar border (59.8% of isolates) and common (more than 10%) at sites in central Myanmar, eastern Thailand and western Cambodia; however, its prevalence was lower than previously documented in Pailin, western Cambodia. The pfmdr1 Y184F mutation was common, particularly in and around Cambodia, and the F1226Y mutation was found in about half of samples in Mae Sot. The functional significance of these two mutations remains unclear. Other previously documented pfmdr1 mutations were absent or very rare in the region. The pfcrt mutation K76T associated with chloroquine resistance was found in 98.2% of isolates. The CVIET haplotype made up 95% or more of isolates in western SEA while the CVIDT haplotype was common (30-40% of isolates) in north and northeastern Cambodia, southern Laos, and southern Vietnam. CONCLUSIONS: These findings generate cause for concern regarding the mid-term efficacy of artemether-lumefantrine in Myanmar, while the absence of resistance-conferring pfmdr1 mutations and SVMNT pfcrt haplotypes suggests that amodiaquine could be an efficacious component of anti-malarial regimens in SEA.

Nhung NT, Cuong NV, Thwaites G, Carrique-Mas J. 2016. Antimicrobial Usage and Antimicrobial Resistance in Animal Production in Southeast Asia: A Review. Antibiotics (Basel), 5 (4), pp. 37-37. | Citations: 8 (Scopus) | Show Abstract | Read more

Southeast Asia is an area of great economic dynamism. In recent years, it has experienced a rapid rise in the levels of animal product production and consumption. The region is considered to be a hotspot for infectious diseases and antimicrobial resistance (AMR). We reviewed English-language peer-reviewed publications related to antimicrobial usage (AMU) and AMR in animal production, as well as antimicrobial residues in meat and fish from 2000 to 2016, in the region. There is a paucity of data from most countries and for most bacterial pathogens. Most of the published work relates to non-typhoidal Salmonella (NTS), Escherichia coli (E. coli), and Campylobacter spp. (mainly from Vietnam and Thailand), Enterococcus spp. (Malaysia), and methicillin-resistant Staphylococcus aureus (MRSA) (Thailand). However, most studies used the disk diffusion method for antimicrobial susceptibility testing; breakpoints were interpreted using Clinical Standard Laboratory Institute (CSLI) guidelines. Statistical models integrating data from publications on AMR in NTS and E. coli studies show a higher overall prevalence of AMR in pig isolates, and an increase in levels of AMR over the years. AMU studies (mostly from Vietnam) indicate very high usage levels of most types of antimicrobials, including beta-lactams, aminoglycosides, macrolides, and quinolones. This review summarizes information about genetic determinants of resistance, most of which are transferrable (mostly plasmids and integrons). The data in this review provide a benchmark to help focus research and policies on AMU and AMR in the region.

Adhikari B, James N, Newby G, von Seidlein L, White NJ, Day NPJ, Dondorp AM, Pell C, Cheah PY. 2016. Community engagement and population coverage in mass anti-malarial administrations: a systematic literature review. Malar J, 15 (1), pp. 523. | Citations: 7 (Scopus) | Show Abstract | Read more

BACKGROUND: Mass anti-malarial administration has been proposed as a key component of the malaria elimination strategy in South East Asia. The success of this approach depends on the local malaria epidemiology, nature of the anti-malarial regimen and population coverage. Community engagement is used to promote population coverage but little research has systematically analysed its impact. This systematic review examines population coverage and community engagement in programmes of mass anti-malarial drug administration. METHODS: This review builds on a previous review that identified 3049 articles describing mass anti-malarial administrations published between 1913 and 2011. Further search and application of a set of criteria conducted in the current review resulted in 51 articles that were retained for analysis. These 51 papers described the population coverage and/or community engagement in mass anti-malarial administrations. Population coverage was quantitatively assessed and a thematic analysis was conducted on the community engagement activities. RESULTS: The studies were conducted in 26 countries: in diverse healthcare and social contexts where various anti-malarial regimens under varied study designs were administered. Twenty-eight articles reported only population coverage; 12 described only community engagement activities; and 11 community engagement and population coverage. Average population coverage was 83% but methods of calculating coverage were frequently unclear or inconsistent. Community engagement activities included providing health education and incentives, using community structures (e.g. existing hierarchies or health infrastructure), mobilizing human resources, and collaborating with government at some level (e.g. ministries of health). Community engagement was often a process involving various activities throughout the duration of the intervention. CONCLUSION: The mean population coverage was over 80% but incomplete reporting of calculation methods limits conclusions and comparisons between studies. Various community engagement activities and approaches were described, but many articles contained limited or no details. Other factors relevant to population coverage, such as the social, cultural and study context were scarcely reported. Further research is needed to understand the factors that influence population coverage and adherence in mass anti-malarial administrations and the role community engagement activities and approaches play in satisfactory participation.

Atwal S, Giengkam S, VanNieuwenhze M, Salje J. 2016. Live imaging of the genetically intractable obligate intracellular bacteria Orientia tsutsugamushi using a panel of fluorescent dyes. J Microbiol Methods, 130 pp. 169-176. | Citations: 2 (Web of Science Lite) | Show Abstract | Read more

Our understanding of the molecular mechanisms of bacterial infection and pathogenesis are disproportionally derived from a small number of well-characterised species and strains. One reason for this is the enormous time and resources required to develop a new organism into experimental system that can be interrogated at the molecular level, in particular with regards to the development of genetic tools. Live cell imaging by fluorescence microscopy is a powerful technique to study biological processes such as bacterial motility, host cell invasion, and bacterial growth and division. In the absence of genetic tools that enable exogenous expression of fluorescent proteins, fluorescent chemical probes can be used to label and track living cells. A large number of fluorescent chemical probes are commercially available, but these have overwhelmingly been applied to the study of eukaryotic cell systems. Here, we present a methodical analysis of four different classes of probes, which can be used to delineate the cytoplasm, nucleic acids, cell membrane or peptidoglycan of living bacterial cells. We have tested these in the context of the important but neglected human pathogen Orientia tsutsugamushi but expect that the methodology would be broadly applicable to other bacterial species.

Li R, van Doorn HR, Wertheim HFL, Khue LN, Ha NTB, Dat VQ, Hanh CT, Nga DTT, Trang NNM, Nadjm B et al. 2016. Combating antimicrobial resistance: quality standards for prescribing for respiratory infections in Vietnam. Lancet Glob Health, 4 (11), pp. e789. | Read more

Van Kerkhove MD, Reveiz L, Souza JP, Jaenisch T, Carson G, Broutet N, Working Group on ZIKV Harmonized Research. 2016. Harmonisation of Zika virus research protocols to address key public health concerns. Lancet Glob Health, 4 (12), pp. e911-e912. | Citations: 1 (Web of Science Lite) | Read more

Snow RW. 2016. Seasonal Malaria Chemoprevention: An Evolving Research Paradigm. PLoS Med, 13 (11), pp. e1002176. | Citations: 1 (Web of Science Lite) | Show Abstract | Read more

Robert W. Snow discusses the importance of empirical evidence, such as that provided in the trial published this week by Milligan and colleagues, in guiding malaria control in Africa.

Inzaule SC, Hamers RL, Kityo C, Rinke de Wit TF, Roura M. 2016. Long-Term Antiretroviral Treatment Adherence in HIV-Infected Adolescents and Adults in Uganda: A Qualitative Study. PLoS One, 11 (11), pp. e0167492. | Citations: 3 (Scopus) | Show Abstract | Read more

BACKGROUND: Long-term success of HIV antiretroviral therapy requires near-perfect adherence, maintained throughout one's lifetime. However, perceptions towards ART and patterns of adherence may change during the life course. We assessed challenges to long-term adherence in adolescents and adults in three regional HIV treatment centers in Uganda. METHODS: We conducted 24 in-depth interviews and 2 focus group discussions with a total of 33 health-care providers and expert clients (HIV patients on long-term ART who assist with adherence support of fellow patients). Interview topics included experiences with patients on long-term treatment with either declining adherence or persistent poor adherence. Transcribed texts were coded and analyzed based on the social-ecological framework highlighting differences and commonalities between adolescents and adults. RESULTS: The overarching themes in adolescents were unstructured treatment holidays, delays in disclosure of HIV status by caretakers, stigma, which was mainly experienced in boarding schools, and diminishing or lack of clinical support. In particular, there was minimal support for early and gradual disclosure for caretakers to the infected children, diminishing clinical support for young adults during transition to adult-based care and declining peer-to-peer support group activities. The predominating theme in adults was challenges with treatment access among temporary economic migrants. Common themes to adults and adolescents were challenges with disclosure in intimate relationships, treatment related factors including side effects, supply of single tablets in place of fixed-dose combined drugs, supply of drug brands with unfavorable taste and missed opportunities for counseling due to shortage of staff. CONCLUSION: Adherence counseling and support should be adapted differently for adolescents and adults and to the emerging life course challenges in long-term treated patients. Programs should also address constraints experienced by temporary economic migrants to ensure continuity of treatment within the host country.

Inzaule SC, Ondoa P, Peter T, Mugyenyi PN, Stevens WS, de Wit TFR, Hamers RL. 2016. Affordable HIV drug-resistance testing for monitoring of antiretroviral therapy in sub-Saharan Africa. Lancet Infect Dis, 16 (11), pp. e267-e275. | Citations: 7 (Scopus) | Show Abstract | Read more

Increased provision of antiretroviral therapy in sub-Saharan Africa has led to a growing number of patients with therapy failure and acquired drug-resistant HIV, driving the demand for more costly further lines of antiretroviral therapy. In conjunction with accelerated access to viral load monitoring, feasible and affordable technologies to detect drug-resistant HIV could help maximise the durability and rational use of available drug regimens. Potential low-cost technologies include in-house Sanger and next-generation sequencing in centralised laboratories, and point mutation assays and genotype-free systems that predict response to antiretroviral therapy at point-of-care. Strengthening of centralised high-throughput laboratories, including efficient systems for sample referral and results delivery, will increase economies-of-scale while reducing costs. Access barriers can be mitigated by standardisation of in-house assays into commercial kits, use of polyvalent instruments, and adopting price-reducing strategies. A stepwise rollout approach should improve feasibility, prioritising WHO-recommended population-based surveillance and management of complex patient categories, such as patients failing protease inhibitor-based antiretroviral therapy. Implementation research, adaptations of existing WHO guidance, and political commitment, will be key to support the appropriate investments and policy changes. In this Personal View, we discuss the potential role of HIV drug resistance testing for population-based surveillance and individual patient management in sub-Saharan Africa. We review the strengths and challenges of promising low-cost technologies and how they can be implemented.

Leang R, Khu NH, Mukaka M, Debackere M, Tripura R, Kheang ST, Chy S, Kak N, Buchy P, Tarantola A et al. 2016. An optimised age-based dosing regimen for single low-dose primaquine for blocking malaria transmission in Cambodia. BMC Med, 14 (1), pp. 171. | Citations: 2 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: In 2012, the World Health Organization recommended the addition of single low-dose primaquine (SLDPQ, 0.25 mg base/kg body weight) to artemisinin combination therapies to block the transmission of Plasmodium falciparum without testing for glucose-6-phosphate dehydrogenase deficiency. The targeted group was non-pregnant patients aged ≥ 1 year (later changed to ≥ 6 months) with acute uncomplicated falciparum malaria, primarily in countries with artemisinin-resistant P. falciparum (ARPf). No dosing regimen was suggested, leaving malaria control programmes and clinicians in limbo. Therefore, we designed a user-friendly, age-based SLDPQ regimen for Cambodia, the country most affected by ARPf. METHODS: By reviewing primaquine's pharmacology, we defined a therapeutic dose range of 0.15-0.38 mg base/kg (9-22.5 mg in a 60-kg adult) for a therapeutic index of 2.5. Primaquine doses (1-20 mg) were tested using a modelled, anthropometric database of 28,138 Cambodian individuals (22,772 healthy, 4119 with malaria and 1247 with other infections); age distributions were: 0.5-4 years (20.0 %, n = 5640), 5-12 years (9.1 %, n = 2559), 13-17 years (9.1 %, n = 2550), and ≥ 18 years (61.8 %, n = 17,389). Optimal age-dosing groups were selected according to calculated mg base/kg doses and proportions of individuals receiving a therapeutic dose. RESULTS: Four age-dosing bands were defined: (1) 0.5-4 years, (2) 5-9 years, (3) 10-14 years, and (4) ≥15 years to receive 2.5, 5, 7.5, and 15 mg of primaquine base, resulting in therapeutic doses in 97.4 % (5494/5640), 90.5 % (1511/1669), 97.7 % (1473/1508), and 95.7 % (18,489/19,321) of individuals, respectively. Corresponding median (1st-99th centiles) mg base/kg doses of primaquine were (1) 0.23 (0.15-0.38), (2) 0.29 (0.18-0.45), (3) 0.27 (0.15-0.39), and (4) 0.29 (0.20-0.42). CONCLUSIONS: This age-based SLDPQ regimen could contribute substantially to malaria elimination and requires urgent evaluation in Cambodia and other countries with similar anthropometric characteristics. It guides primaquine manufacturers on suitable tablet strengths and doses for paediatric-friendly formulations. Development of similar age-based dosing recommendations for Africa is needed.

Puckett EE, Park J, Combs M, Blum MJ, Bryant JE, Caccone A, Costa F, Deinum EE, Esther A, Himsworth CG et al. 2016. Global population divergence and admixture of the brown rat (Rattus norvegicus). Proc Biol Sci, 283 (1841), pp. 20161762-20161762. | Citations: 3 (Web of Science Lite) | Show Abstract | Read more

Native to China and Mongolia, the brown rat (Rattus norvegicus) now enjoys a worldwide distribution. While black rats and the house mouse tracked the regional development of human agricultural settlements, brown rats did not appear in Europe until the 1500s, suggesting their range expansion was a response to relatively recent increases in global trade. We inferred the global phylogeography of brown rats using 32 k SNPs, and detected 13 evolutionary clusters within five expansion routes. One cluster arose following a southward expansion into Southeast Asia. Three additional clusters arose from two independent eastward expansions: one expansion from Russia to the Aleutian Archipelago, and a second to western North America. Westward expansion resulted in the colonization of Europe from which subsequent rapid colonization of Africa, the Americas and Australasia occurred, and multiple evolutionary clusters were detected. An astonishing degree of fine-grained clustering between and within sampling sites underscored the extent to which urban heterogeneity shaped genetic structure of commensal rodents. Surprisingly, few individuals were recent migrants, suggesting that recruitment into established populations is limited. Understanding the global population structure of R. norvegicus offers novel perspectives on the forces driving the spread of zoonotic disease, and aids in development of rat eradication programmes.

Karki M, Pandit S, Baker S, Basnyat B. 2016. Cotrimoxazole treats fluoroquinolone-resistant Salmonella typhi H58 infection. BMJ Case Rep, 2016 pp. bcr2016217223-bcr2016217223. | Citations: 3 (Scopus) | Show Abstract | Read more

A woman aged 20 years presented with fever and no localising signs. She was treated with cotrimoxazole and the subsequent blood culture was positive for Salmonella typhi (S. typhi), which was resistant to fluoroquinolones but susceptible to cotrimoxazole. Genotyping identified an FQ-R subclade of H58 S. typhi Fever clearance time was 4 days after starting the antibiotics, and no relapses were noted on 2 months of follow-up. This inexpensive, well-known and easily available antimicrobial could be suitably redeployed for fluoroquinolone-resistant enteric fever in South Asia.

Williamson AE, Ylioja PM, Robertson MN, Antonova-Koch Y, Avery V, Baell JB, Batchu H, Batra S, Burrows JN, Bhattacharyya S et al. 2016. Open Source Drug Discovery: Highly Potent Antimalarial Compounds Derived from the Tres Cantos Arylpyrroles. ACS Cent Sci, 2 (10), pp. 687-701. | Citations: 8 (Scopus) | Show Abstract | Read more

The development of new antimalarial compounds remains a pivotal part of the strategy for malaria elimination. Recent large-scale phenotypic screens have provided a wealth of potential starting points for hit-to-lead campaigns. One such public set is explored, employing an open source research mechanism in which all data and ideas were shared in real time, anyone was able to participate, and patents were not sought. One chemical subseries was found to exhibit oral activity but contained a labile ester that could not be replaced without loss of activity, and the original hit exhibited remarkable sensitivity to minor structural change. A second subseries displayed high potency, including activity within gametocyte and liver stage assays, but at the cost of low solubility. As an open source research project, unexplored avenues are clearly identified and may be explored further by the community; new findings may be cumulatively added to the present work.

Grist EPM, Flegg JA, Humphreys G, Mas IS, Anderson TJC, Ashley EA, Day NPJ, Dhorda M, Dondorp AM, Faiz MA et al. 2016. Optimal health and disease management using spatial uncertainty: a geographic characterization of emergent artemisinin-resistant Plasmodium falciparum distributions in Southeast Asia. Int J Health Geogr, 15 (1), pp. 37. | Citations: 3 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Artemisinin-resistant Plasmodium falciparum malaria parasites are now present across much of mainland Southeast Asia, where ongoing surveys are measuring and mapping their spatial distribution. These efforts require substantial resources. Here we propose a generic 'smart surveillance' methodology to identify optimal candidate sites for future sampling and thus map the distribution of artemisinin resistance most efficiently. METHODS: The approach uses the 'uncertainty' map generated iteratively by a geostatistical model to determine optimal locations for subsequent sampling. RESULTS: The methodology is illustrated using recent data on the prevalence of the K13-propeller polymorphism (a genetic marker of artemisinin resistance) in the Greater Mekong Subregion. CONCLUSION: This methodology, which has broader application to geostatistical mapping in general, could improve the quality and efficiency of drug resistance mapping and thereby guide practical operations to eliminate malaria in affected areas.

Denoeud-Ndam L, Dicko A, Baudin E, Guindo O, Grandesso F, Diawara H, Sissoko S, Sanogo K, Traoré S, Keita S et al. 2016. Efficacy of artemether-lumefantrine in relation to drug exposure in children with and without severe acute malnutrition: an open comparative intervention study in Mali and Niger. BMC Med, 14 (1), pp. 167. | Show Abstract | Read more

BACKGROUND: Severe acute malnutrition (SAM) affects almost all organs and has been associated with reduced intestinal absorption of medicines. However, very limited information is available on the pharmacokinetic properties of antimalarial drugs in this vulnerable population. We assessed artemether-lumefantrine (AL) clinical efficacy in children with SAM compared to those without. METHODS: Children under 5 years of age with uncomplicated P. falciparum malaria were enrolled between November 2013 and January 2015 in Mali and Niger, one third with uncomplicated SAM and two thirds without. AL was administered under direct observation with a fat intake consisting of ready-to-use therapeutic food (RUTF - Plumpy'Nut®) in SAM children, twice daily during 3 days. Children were followed for 42 days, with PCR-corrected adequate clinical and parasitological response (ACPR) at day 28 as the primary outcome. Lumefantrine concentrations were assessed in a subset of participants at different time points, including systematic measurements on day 7. RESULTS: A total of 399 children (360 in Mali and 39 in Niger) were enrolled. Children with SAM were younger than their non-SAM counterparts (mean 17 vs. 28 months, P < 0.0001). PCR-corrected ACPR was 100 % (95 % CI, 96.8-100 %) in SAM at both day 28 and 42, versus 98.8 % (96.4-99.7 %) at day 28 and 98.3 % (95.6-99.4 %) at day 42 in non-SAM (P = 0.236 and 0.168, respectively). Compared to younger children, children older than 21 months experienced more reinfections and SAM was associated with a greater risk of reinfection until day 28 (adjusted hazard ratio = 2.10 (1.04-4.22), P = 0.038). Day 7 lumefantrine concentrations were significantly lower in SAM than non-SAM (median 251 vs. 365 ng/mL, P = 0.049). CONCLUSIONS: This study shows comparable therapeutic efficacy of AL in children without SAM and in those with SAM when given in combination with RUTF, but a higher risk of reinfection in older children suffering from SAM. This could be associated with poorer exposure to the antimalarials as documented by a lower lumefantrine concentration on day 7. TRIAL REGISTRATION: NCT01958905 , registration date: October 7, 2013.

Cowman AF, Healer J, Marapana D, Marsh K. 2016. Malaria: Biology and Disease. Cell, 167 (3), pp. 610-624. | Citations: 25 (Scopus) | Show Abstract | Read more

Malaria has been a major global health problem of humans through history and is a leading cause of death and disease across many tropical and subtropical countries. Over the last fifteen years renewed efforts at control have reduced the prevalence of malaria by over half, raising the prospect that elimination and perhaps eradication may be a long-term possibility. Achievement of this goal requires the development of new tools including novel antimalarial drugs and more efficacious vaccines as well as an increased understanding of the disease and biology of the parasite. This has catalyzed a major effort resulting in development and regulatory approval of the first vaccine against malaria (RTS,S/AS01) as well as identification of novel drug targets and antimalarial compounds, some of which are in human clinical trials.

Bang ND, Caws M, Truc TT, Duong TN, Dung NH, Ha DTM, Thwaites GE, Heemskerk D, Tarning J, Merson L et al. 2016. Clinical presentations, diagnosis, mortality and prognostic markers of tuberculous meningitis in Vietnamese children: a prospective descriptive study. BMC Infect Dis, 16 (1), pp. 573. | Citations: 4 (Scopus) | Show Abstract | Read more

BACKGROUND: Tuberculous meningitis in adults is well characterized in Vietnam, but there are no data on the disease in children. We present a prospective descriptive study of Vietnamese children with TBM to define the presentation, course and characteristics associated with poor outcome. METHODS: A prospective descriptive study of 100 consecutively admitted children with TBM at Pham Ngoc Thach Hospital, Ho Chi Minh City. Cox and logistic regression were used to identify factors associated with risk of death and a combined endpoint of death or disability at treatment completion. RESULTS: The study enrolled from October 2009 to March 2011. Median age was 32.5 months; sex distribution was equal. Median duration of symptoms was 18.5 days and time from admission to treatment initiation was 11 days. Fifteen of 100 children died, 4 were lost to follow-up, and 27/81 (33 %) of survivors had intermediate or severe disability upon treatment completion. Microbiological confirmation of disease was made in 6 %. Baseline characteristics associated with death included convulsions (HR 3.46, 95CI 1.19-10.13, p = 0.02), decreased consciousness (HR 22.9, 95CI 3.01-174.3, p < 0.001), focal neurological deficits (HR 15.7, 95CI 1.67-2075, p = 0.01), Blantyre Coma Score (HR 3.75, 95CI 0.99-14.2, p < 0.001) and CSF protein, lactate and glucose levels. Neck stiffness, MRC grade (children aged >5 years) and hydrocephalus were also associated with the combined endpoint of death or disability. CONCLUSIONS: Tuberculous meningitis in Vietnamese children has significant mortality and morbidity. There is significant delay in diagnosis; interventions that increase the speed of diagnosis and treatment initiation are likely to improve outcomes.

Amboko BI, Ayieko P, Ogero M, Julius T, Irimu G, English M, Clinical Information Network authors. 2016. Malaria investigation and treatment of children admitted to county hospitals in western Kenya. Malar J, 15 (1), pp. 506. | Show Abstract | Read more

BACKGROUND: Up to 90 % of the global burden of malaria morbidity and mortality occurs in sub-Saharan Africa and children under-five bear a disproportionately high malaria burden. Effective inpatient case management can reduce severe malaria mortality and morbidity, but there are few reports of how successfully international and national recommendations are adopted in management of inpatient childhood malaria. METHODS: A descriptive cross-sectional study of inpatient malaria case management practices was conducted using data collected over 24 months in five hospitals from high malaria risk areas participating in the Clinical Information Network (CIN) in Kenya. This study describes documented clinical features, laboratory investigations and treatment of malaria in children (2-59 months) and adherence to national guidelines. RESULTS: A total of 13,014 children had a malaria diagnosis on admission to the five hospitals between March, 2014 and February, 2016. Their median age was 24 months (IQR 12-36 months). The proportion with a diagnostic test for malaria requested was 11,981 (92.1 %). Of 10,388 patients with malaria test results documented, 8050 (77.5 %) were positive and anti-malarials were prescribed in 6745 (83.8 %). Malaria treatment was prescribed in 1613/2338 (69.0 %) children with a negative malaria result out of which only 52 (3.2 %) had a repeat malaria test done as recommended in national guidelines. Documentation of clinical features was good across all hospitals, but quinine remained the most prescribed malaria drug (47.2 % of positive cases) although a transition to artesunate (46.1 %) was observed. Although documented clinical features suggested approximately half of positive malaria patients were not severe cases artemether-lumefantrine was prescribed on admission in only 3.7 % cases. CONCLUSIONS: Despite improvements in inpatient malaria care, high rates of presumptive treatment for test negative children and likely over-use of injectable anti-malarial drugs were observed. Three years after national policy change, there is a gradual transition to artesunate. Continued efforts to support improved routine inpatient malaria care through dissemination and implementation of guidelines, and access to recommended drugs are needed together with improved capacity of hospitals to investigate other causes of severe illness in children. Efforts to improve clinical information could help track progress.

Hodgson SH, Llewellyn D, Silk SE, Milne KH, Elias SC, Miura K, Kamuyu G, Juma EA, Magiri C, Muia A et al. 2016. Changes in Serological Immunology Measures in UK and Kenyan Adults Post-controlled Human Malaria Infection. Front Microbiol, 7 (OCT), pp. 1604. | Citations: 4 (Scopus) | Show Abstract | Read more

Background: The timing of infection is closely determined in controlled human malaria infection (CHMI) studies, and as such they provide a unique opportunity to dissect changes in immunological responses before and after a single infection. The first Kenyan Challenge Study (KCS) (Pan African Clinical Trial Registry: PACTR20121100033272) was performed in 2013 with the aim of establishing the CHMI model in Kenya. This study used aseptic, cryopreserved, attenuated Plasmodium falciparum sporozoites administered by needle and syringe (PfSPZ Challenge) and was the first to evaluate parasite dynamics post-CHMI in individuals with varying degrees of prior exposure to malaria. Methods: We describe detailed serological and functional immunological responses pre- and post-CHMI for participants in the KCS and compare these with those from malaria-naïve UK volunteers who also underwent CHMI (VAC049) ( NCT01465048) using PfSPZ Challenge. We assessed antibody responses to three key blood-stage merozoite antigens [merozoite surface protein 1 (MSP1), apical membrane protein 1 (AMA1), and reticulocyte-binding protein homolog 5 (RH5)] and functional activity using two candidate measures of anti-merozoite immunity; the growth inhibition activity (GIA) assay and the antibody-dependent respiratory burst activity (ADRB) assay. Results:Clear serological differences were observed pre- and post-CHMI by ELISA between malaria-naïve UK volunteers in VAC049, and Kenyan volunteers who had prior malaria exposure. Antibodies to AMA1 and schizont extract correlated with parasite multiplication rate (PMR) post-CHMI in KCS. Serum from volunteer 110 in KCS, who demonstrated a dramatically reduced PMR in vivo, had no in vitro GIA prior to CHMI but the highest level of ADRB activity. A significant difference in ADRB activity was seen between KCS volunteers with minimal and definite prior exposure to malaria and significant increases were seen in ADRB activity post-CHMI in Kenyan volunteers. Quinine and atovaquone/proguanil, previously assumed to be removed by IgG purification, were identified as likely giving rise to aberrantly high in vitro GIA results. Conclusions: The ADRB activity assay is a promising functional assay that warrants further investigation as a measure of prior exposure to malaria and predictor of control of parasite growth. The CHMI model can be used to evaluate potential measures of naturally-acquired immunity to malaria.

Maude RR, Ghose A, Samad R, de Jong HK, Fukushima M, Wijedoru L, Hassan MU, Hossain MA, Karim MR, Sayeed AA et al. 2016. A prospective study of the importance of enteric fever as a cause of non-malarial febrile illness in patients admitted to Chittagong Medical College Hospital, Bangladesh. BMC Infect Dis, 16 (1), pp. 567. | Show Abstract | Read more

BACKGROUND: Fever is a common cause of hospital admission in Bangladesh but causative agents, other than malaria, are not routinely investigated. Enteric fever is thought to be common. METHODS: Adults and children admitted to Chittagong Medical College Hospital with a temperature of ≥38.0 °C were investigated using a blood smear for malaria, a blood culture, real-time PCR to detect Salmonella Typhi, S. Paratyphi A and other pathogens in blood and CSF and an NS1 antigen dengue ELISA. RESULTS: We enrolled 300 febrile patients with a negative malaria smear between January and June 2012: 156 children (aged ≤15 years) and 144 adults with a median (interquartile range) age of 13 (5-31) years and median (IQR) illness duration before admission of five (2-8) days. Clinical enteric fever was diagnosed in 52 patients (17.3 %), lower respiratory tract infection in 48 (16.0 %), non-specific febrile illness in 48 (16.0 %), a CNS infection in 37 patients (12.3 %), urinary sepsis in 23 patients (7.7 %), an upper respiratory tract infection in 21 patients (7.0 %), and diarrhea or dysentery in 21 patients (7.0 %). Malaria was still suspected in seven patients despite a negative microscopy test. S. Typhi was detected in blood by culture or PCR in 34 (11.3 %) of patients. Of note Rickettsia typhi and Orientia tsutsugamushi were detected by PCR in two and one patient respectively. Twenty-nine (9 %) patients died during their hospital admission (15/160 (9.4 %) of children and 14/144 (9.7 %) adults). Two of 52 (3.8 %) patients with enteric fever, 5/48 (10.4 %) patients with lower respiratory tract infections, and 12/37 (32.4 %) patients with CNS infection died. CONCLUSION: Enteric fever was confirmed in 11.3 % of patients admitted to this hospital in Bangladesh with non-malaria fever. Lower respiratory tract and CNS infections were also common. CNS infections in this location merit more detailed study due to the high mortality.

Basnyat B. 2016. Typhoid versus typhus fever in post-earthquake Nepal. Lancet Glob Health, 4 (8), pp. e516-e517. | Citations: 6 (Scopus) | Read more

Grue L, Siddiqui S, Limmathurotsakul D, Kamaludi A, Karyana M, Lau C-Y. 2016. Commentary: data sharing in South East Asia. BMJ, 355 pp. i5363. | Read more

Pisani E, Aaby P, Breugelmans JG, Carr D, Groves T, Helinski M, Kamuya D, Kern S, Littler K, Marsh V et al. 2016. Beyond open data: realising the health benefits of sharing data. BMJ, 355 pp. i5295. | Citations: 2 (Web of Science Lite) | Read more

GBD 2015 Child Mortality Collaborators. 2016. Global, regional, national, and selected subnational levels of stillbirths, neonatal, infant, and under-5 mortality, 1980-2015: a systematic analysis for the Global Burden of Disease Study 2015. Lancet, 388 (10053), pp. 1725-1774. | Citations: 58 (Scopus) | Show Abstract | Read more

BACKGROUND: Established in 2000, Millennium Development Goal 4 (MDG4) catalysed extraordinary political, financial, and social commitments to reduce under-5 mortality by two-thirds between 1990 and 2015. At the country level, the pace of progress in improving child survival has varied markedly, highlighting a crucial need to further examine potential drivers of accelerated or slowed decreases in child mortality. The Global Burden of Disease 2015 Study (GBD 2015) provides an analytical framework to comprehensively assess these trends for under-5 mortality, age-specific and cause-specific mortality among children under 5 years, and stillbirths by geography over time. METHODS: Drawing from analytical approaches developed and refined in previous iterations of the GBD study, we generated updated estimates of child mortality by age group (neonatal, post-neonatal, ages 1-4 years, and under 5) for 195 countries and territories and selected subnational geographies, from 1980-2015. We also estimated numbers and rates of stillbirths for these geographies and years. Gaussian process regression with data source adjustments for sampling and non-sampling bias was applied to synthesise input data for under-5 mortality for each geography. Age-specific mortality estimates were generated through a two-stage age-sex splitting process, and stillbirth estimates were produced with a mixed-effects model, which accounted for variable stillbirth definitions and data source-specific biases. For GBD 2015, we did a series of novel analyses to systematically quantify the drivers of trends in child mortality across geographies. First, we assessed observed and expected levels and annualised rates of decrease for under-5 mortality and stillbirths as they related to the Soci-demographic Index (SDI). Second, we examined the ratio of recorded and expected levels of child mortality, on the basis of SDI, across geographies, as well as differences in recorded and expected annualised rates of change for under-5 mortality. Third, we analysed levels and cause compositions of under-5 mortality, across time and geographies, as they related to rising SDI. Finally, we decomposed the changes in under-5 mortality to changes in SDI at the global level, as well as changes in leading causes of under-5 deaths for countries and territories. We documented each step of the GBD 2015 child mortality estimation process, as well as data sources, in accordance with the Guidelines for Accurate and Transparent Health Estimates Reporting (GATHER). FINDINGS: Globally, 5·8 million (95% uncertainty interval [UI] 5·7-6·0) children younger than 5 years died in 2015, representing a 52·0% (95% UI 50·7-53·3) decrease in the number of under-5 deaths since 1990. Neonatal deaths and stillbirths fell at a slower pace since 1990, decreasing by 42·4% (41·3-43·6) to 2·6 million (2·6-2·7) neonatal deaths and 47·0% (35·1-57·0) to 2·1 million (1·8-2·5) stillbirths in 2015. Between 1990 and 2015, global under-5 mortality decreased at an annualised rate of decrease of 3·0% (2·6-3·3), falling short of the 4·4% annualised rate of decrease required to achieve MDG4. During this time, 58 countries met or exceeded the pace of progress required to meet MDG4. Between 2000, the year MDG4 was formally enacted, and 2015, 28 additional countries that did not achieve the 4·4% rate of decrease from 1990 met the MDG4 pace of decrease. However, absolute levels of under-5 mortality remained high in many countries, with 11 countries still recording rates exceeding 100 per 1000 livebirths in 2015. Marked decreases in under-5 deaths due to a number of communicable diseases, including lower respiratory infections, diarrhoeal diseases, measles, and malaria, accounted for much of the progress in lowering overall under-5 mortality in low-income countries. Compared with gains achieved for infectious diseases and nutritional deficiencies, the persisting toll of neonatal conditions and congenital anomalies on child survival became evident, especially in low-income and low-middle-income countries. We found sizeable heterogeneities in comparing observed and expected rates of under-5 mortality, as well as differences in observed and expected rates of change for under-5 mortality. At the global level, we recorded a divergence in observed and expected levels of under-5 mortality starting in 2000, with the observed trend falling much faster than what was expected based on SDI through 2015. Between 2000 and 2015, the world recorded 10·3 million fewer under-5 deaths than expected on the basis of improving SDI alone. INTERPRETATION: Gains in child survival have been large, widespread, and in many places in the world, faster than what was anticipated based on improving levels of development. Yet some countries, particularly in sub-Saharan Africa, still had high rates of under-5 mortality in 2015. Unless these countries are able to accelerate reductions in child deaths at an extraordinary pace, their achievement of proposed SDG targets is unlikely. Improving the evidence base on drivers that might hasten the pace of progress for child survival, ranging from cost-effective intervention packages to innovative financing mechanisms, is vital to charting the pathways for ultimately ending preventable child deaths by 2030. FUNDING: Bill & Melinda Gates Foundation.

White AL, Min TH, Gross MM, Kajeechiwa L, Thwin MM, Hanboonkunupakarn B, Than HH, Zin TW, Rijken MJ, Hoogenboom G, McGready R. 2016. Accelerated Training of Skilled Birth Attendants in a Marginalized Population on the Thai-Myanmar Border: A Multiple Methods Program Evaluation. PLoS One, 11 (10), pp. e0164363. | Citations: 2 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: To evaluate a skilled birth attendant (SBA) training program in a neglected population on the Thai-Myanmar border, we used multiple methods to show that refugee and migrant health workers can be given effective training in their own environment to become SBAs and teachers of SBAs. The loss of SBAs through resettlement to third countries necessitated urgent training of available workers to meet local needs. METHODS AND FINDINGS: All results were obtained from student records of theory grades and clinical log books. Qualitative evaluation of both the SBA and teacher programs was obtained using semi-structured interviews with supervisors and teachers. We also reviewed perinatal indicators over an eight-year period, starting prior to the first training program until after the graduation of the fourth cohort of SBAs. RESULTS: Four SBA training programs scheduled between 2009 and 2015 resulted in 79/88 (90%) of students successfully completing a training program of 250 theory hours and 625 supervised clinical hours. All 79 students were able to: achieve pass grades on theory examination (median 80%, range [70-89]); obtain the required clinical experience within twelve months; achieve clinical competence to provide safe care during childbirth. In 2010-2011, five experienced SBAs completed a train-the-trainer (TOT) program and went on to facilitate further training programs. Perinatal indicators within Shoklo Malaria Research Unit (SMRU), such as place of birth, maternal and newborn outcomes, showed no significant differences before and after introduction of training or following graduate deployment in the local maternity units. Confidence, competence and teamwork emerged from qualitative evaluation by senior SBAs working with and supervising students in the clinics. CONCLUSIONS: We demonstrate that in resource-limited settings or in marginalized populations, it is possible to accelerate training of skilled birth attendants to provide safe maternity care. Education needs to be tailored to local needs to ensure evidence-based care of women and their families.

McGuinness SL, Whiting SE, Baird R, Currie BJ, Ralph AP, Anstey NM, Price RN, Davis JS, Tong SYC. 2016. Nocardiosis in the tropical northern territory of Australia, 1997-2014 Open Forum Infectious Diseases, 3 (4), pp. 1-25. | Citations: 2 (Scopus) | Show Abstract

© 2016 The Author. Background: Nocardia is an opportunistic pathogen that can cause life-threatening disease. We aimed to characterise the epidemiological, microbiological and clinical features of nocardiosis in the tropical north of Australia. Methods: We conducted a retrospective cohort study of nocardiosis diagnosed between 1997 and 2014. Population-based incidences were calculated using district population data. Results: Clinically significant nocardiosis was identified in sixty-one patients. The unadjusted population-based annual incidence of nocardiosis was 2.02 (95% confidence interval [CI] 1.55-2.60) per 100,000 people and was 1.7 (95% CI 0.96-2.90) fold higher in Indigenous compared with non-Indigenous persons (p=0.027). Of 61 patients, 47 (77%) had chronic lung disease, diabetes and/or hazardous alcohol consumption; 22 (36%) were immunocompromised; and 8 (13%) had no identified comorbidities. Disease presentations included pulmonary (69%; 42/61), cutaneous (13%, 8/61) and disseminated nocardiosis (15%, 9/61). The most commonly identified species were N. asteroides and N. cyriacigeorgica (each 11%). Linezolid was the only antimicrobial to which isolates were universally susceptible; 89% (48/54), 60% (32/53) and 48% (26/54) of isolates were susceptible to trimethoprim-sulfamethoxazole, ceftriaxone and imipenem, respectively. 18 patients (30%) required intensive care unit (ICU) admission and one-year mortality was 31%. Conclusions: The incidence of nocardiosis in tropical Australia is amongst the highest reported globally. Nocardiosis occurs in both immunocompromised and immunocompetent hosts, and is associated with high rates of ICU-admission, 1-year mortality and resistance to commonly-recommended antimicrobials. Diagnosis should be considered in patients with consistent clinical features, particularly if they are Indigenous or have chronic lung disease.

Baird JK, Valecha N, Duparc S, White NJ, Price RN. 2016. Diagnosis and Treatment of Plasmodium vivax Malaria. Am J Trop Med Hyg, 95 (6 Suppl), pp. 35-51. | Citations: 4 (Web of Science Lite) | Show Abstract | Read more

The diagnosis and treatment of Plasmodium vivax malaria differs from that of Plasmodium falciparum malaria in fundamentally important ways. This article reviews the guiding principles, practices, and evidence underpinning the diagnosis and treatment of P. vivax malaria.

Surjadjaja C, Surya A, Baird JK. 2016. Epidemiology of Plasmodium vivax in Indonesia. Am J Trop Med Hyg, 95 (6 Suppl), pp. 121-132. | Citations: 1 (Web of Science Lite) | Show Abstract | Read more

Endemic malaria occurs across much of the vast Indonesian archipelago. All five species of Plasmodium known to naturally infect humans occur here, along with 20 species of Anopheles mosquitoes confirmed as carriers of malaria. Two species of plasmodia cause the overwhelming majority and virtually equal shares of malaria infections in Indonesia: Plasmodium falciparum and Plasmodium vivax The challenge posed by P. vivax is especially steep in Indonesia because chloroquine-resistant strains predominate, along with Chesson-like strains that relapse quickly and multiple times at short intervals in almost all patients. Indonesia's hugely diverse human population carries many variants of glucose-6-phosphate dehydrogenase (G6PD) deficiency, most of them exhibiting severely impaired enzyme activity. Therefore, the patients most likely to benefit from primaquine therapy by preventing aggressive relapse, may also be most likely to suffer harm without G6PD deficiency screening. Indonesia faces the challenge of controlling and eventually eliminating malaria across > 13,500 islands stretching > 5,000 km and an enormous diversity of ecological, ethnographic, and socioeconomic settings, and extensive human migrations. This article describes the occurrence of P. vivax in Indonesia and the obstacles faced in eliminating its transmission.

Baird JK. 2016. Attacking Plasmodium vivax. Am J Trop Med Hyg, 95 (6 Suppl), pp. 1-3. | Citations: 1 (Scopus) | Show Abstract | Read more

Discussions beginning in 2012 ultimately led to a landmark document from the World Health Organization (WHO) titled, Control and Elimination of Plasmodium vivax: A Technical Brief, published in July 2015. That body of work represents multiple expert consultations coordinated by the WHO Global Malaria Program, along with technical consensus gathering from national malaria control programs via the WHO regional offices around the globe. That document thus represents thoroughly vetted state-of-the-art recommendations for dealing specifically with P. vivax, the first assembly of such by the WHO. This supplement to the journal was commissioned by the WHO and compiles the very substantial body of evidence and analysis informing those recommendations. This introductory narrative to the supplement provides the historical and technological context of global strategy for combatting P. vivax and reducing the burdens of morbidity and mortality it imposes.

Wong VK, Baker S, Connor TR, Pickard D, Page AJ, Dave J, Murphy N, Holliman R, Sefton A, Millar M et al. 2016. An extended genotyping framework for Salmonella enterica serovar Typhi, the cause of human typhoid. Nat Commun, 7 pp. 12827. | Citations: 9 (Web of Science Lite) | Show Abstract | Read more

The population of Salmonella enterica serovar Typhi (S. Typhi), the causative agent of typhoid fever, exhibits limited DNA sequence variation, which complicates efforts to rationally discriminate individual isolates. Here we utilize data from whole-genome sequences (WGS) of nearly 2,000 isolates sourced from over 60 countries to generate a robust genotyping scheme that is phylogenetically informative and compatible with a range of assays. These data show that, with the exception of the rapidly disseminating H58 subclade (now designated genotype 4.3.1), the global S. Typhi population is highly structured and includes dozens of subclades that display geographical restriction. The genotyping approach presented here can be used to interrogate local S. Typhi populations and help identify recent introductions of S. Typhi into new or previously endemic locations, providing information on their likely geographical source. This approach can be used to classify clinical isolates and provides a universal framework for further experimental investigations.

McGuinness SL, Whiting SE, Baird R, Currie BJ, Ralph AP, Anstey NM, Price RN, Davis JS, Tong SYC. 2016. Nocardiosis in the Tropical Northern Territory of Australia, 1997-2014. Open Forum Infect Dis, 3 (4), pp. ofw208. | Show Abstract | Read more

BACKGROUND: Nocardia is an opportunistic pathogen that can cause life-threatening disease. We aimed to characterize the epidemiological, microbiological, and clinical features of nocardiosis in the tropical north of Australia. METHODS: We conducted a retrospective cohort study of nocardiosis diagnosed between 1997 and 2014. Population-based incidences were calculated using district population data. RESULTS: Clinically significant nocardiosis was identified in 61 patients. The unadjusted population-based annual incidence of nocardiosis was 2.02 (95% confidence interval [CI], 1.55-2.60) per 100000 people and was 1.7 (95% CI, .96-2.90) fold higher in Indigenous compared with non-Indigenous persons (P = .027). Of 61 patients, 47 (77%) had chronic lung disease, diabetes, and/or hazardous alcohol consumption; 22 (36%) were immunocompromised; and 8 (13%) had no identified comorbidities. Disease presentations included pulmonary (69%; 42 of 61), cutaneous (13%; 8 of 61), and disseminated nocardiosis (15%; 9 of 61). The most commonly identified species were Nocardia asteroides and Nocardia cyriacigeorgica (each 11%). Linezolid was the only antimicrobial to which isolates were universally susceptible; 89% (48 of 54), 60% (32 of 53), and 48% (26 of 54) of isolates were susceptible to trimethoprim-sulfamethoxazole, ceftriaxone, and imipenem, respectively. Eighteen patients (30%) required intensive care unit (ICU) admission, and 1-year mortality was 31%. CONCLUSIONS: The incidence of nocardiosis in tropical Australia is amongst the highest reported globally. Nocardiosis occurs in both immunocompromised and immunocompetent hosts, and it is associated with high rates of ICU admission, 1-year mortality, and resistance to commonly recommended antimicrobials. Diagnosis should be considered in patients with consistent clinical features, particularly if they are Indigenous or have chronic lung disease.

Le Bihan A, de Kanter R, Angulo-Barturen I, Binkert C, Boss C, Brun R, Brunner R, Buchmann S, Burrows J, Dechering KJ et al. 2016. Characterization of Novel Antimalarial Compound ACT-451840: Preclinical Assessment of Activity and Dose-Efficacy Modeling. PLoS Med, 13 (10), pp. e1002138. | Citations: 5 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Artemisinin resistance observed in Southeast Asia threatens the continued use of artemisinin-based combination therapy in endemic countries. Additionally, the diversity of chemical mode of action in the global portfolio of marketed antimalarials is extremely limited. Addressing the urgent need for the development of new antimalarials, a chemical class of potent antimalarial compounds with a novel mode of action was recently identified. Herein, the preclinical characterization of one of these compounds, ACT-451840, conducted in partnership with academic and industrial groups is presented. METHOD AND FINDINGS: The properties of ACT-451840 are described, including its spectrum of activities against multiple life cycle stages of the human malaria parasite Plasmodium falciparum (asexual and sexual) and Plasmodium vivax (asexual) as well as oral in vivo efficacies in two murine malaria models that permit infection with the human and the rodent parasites P. falciparum and Plasmodium berghei, respectively. In vitro, ACT-451840 showed a 50% inhibition concentration of 0.4 nM (standard deviation [SD]: ± 0.0 nM) against the drug-sensitive P. falciparum NF54 strain. The 90% effective doses in the in vivo efficacy models were 3.7 mg/kg against P. falciparum (95% confidence interval: 3.3-4.9 mg/kg) and 13 mg/kg against P. berghei (95% confidence interval: 11-16 mg/kg). ACT-451840 potently prevented male gamete formation from the gametocyte stage with a 50% inhibition concentration of 5.89 nM (SD: ± 1.80 nM) and dose-dependently blocked oocyst development in the mosquito with a 50% inhibitory concentration of 30 nM (range: 23-39). The compound's preclinical safety profile is presented and is in line with the published results of the first-in-man study in healthy male participants, in whom ACT-451840 was well tolerated. Pharmacokinetic/pharmacodynamic (PK/PD) modeling was applied using efficacy in the murine models (defined either as antimalarial activity or as survival) in relation to area under the concentration versus time curve (AUC), maximum observed plasma concentration (Cmax), and time above a threshold concentration. The determination of the dose-efficacy relationship of ACT-451840 under curative conditions in rodent malaria models allowed prediction of the human efficacious exposure. CONCLUSION: The dual activity of ACT-451840 against asexual and sexual stages of P. falciparum and the activity on P. vivax have the potential to meet the specific profile of a target compound that could replace the fast-acting artemisinin component and harbor additional gametocytocidal activity and, thereby, transmission-blocking properties. The fast parasite reduction ratio (PRR) and gametocytocidal effect of ACT-451840 were recently also confirmed in a clinical proof-of-concept (POC) study.

Molyneux S, Tsofa B, Barasa E, Nyikuri MM, Waweru EW, Goodman C, Gilson L. 2016. Research Involving Health Providers and Managers: Ethical Issues Faced by Researchers Conducting Diverse Health Policy and Systems Research in Kenya. Dev World Bioeth, 16 (3), pp. 168-177. | Citations: 1 (Scopus) | Show Abstract | Read more

There is a growing interest in the ethics of Health Policy and Systems Research (HPSR), and especially in areas that have particular ethical salience across HPSR. Hyder et al (2014) provide an initial framework to consider this, and call for more conceptual and empirical work. In this paper, we respond by examining the ethical issues that arose for researchers over the course of conducting three HPSR studies in Kenya in which health managers and providers were key participants. All three studies involved qualitative work including observations and individual and group interviews. Many of the ethical dilemmas researchers faced only emerged over the course of the fieldwork, or on completion, and were related to interactions and relationships between individuals operating at different levels or positions in health/research systems. The dilemmas reveal significant ethical challenges for these forms of HPSR, and show that potential 'solutions' to dilemmas often lead to new issues and complications. Our experiences support the value of research ethics frameworks, and suggest that these can be enriched by incorporating careful consideration of context embedded social relations into research planning and conduct. Many of these essential relational elements of ethical practice, and of producing quality data, are given stronger emphasis in social science research ethics than in epidemiological, clinical or biomedical research ethics, and are particularly relevant where health systems are understood as social and political constructs. We conclude with practical and research implications.

Phan MVT, Anh PH, Cuong NV, Munnink BBO, van der Hoek L, My PT, Tri TN, Bryant JE, Baker S, Thwaites G et al. 2016. Unbiased whole-genome deep sequencing of human and porcine stool samples reveals circulation of multiple groups of rotaviruses and a putative zoonotic infection. Virus Evol, 2 (2), pp. vew027. | Show Abstract | Read more

Coordinated and synchronous surveillance for zoonotic viruses in both human clinical cases and animal reservoirs provides an opportunity to identify interspecies virus movement. Rotavirus (RV) is an important cause of viral gastroenteritis in humans and animals. In this study, we document the RV diversity within co-located humans and animals sampled from the Mekong delta region of Vietnam using a primer-independent, agnostic, deep sequencing approach. A total of 296 stool samples (146 from diarrhoeal human patients and 150 from pigs living in the same geographical region) were directly sequenced, generating the genomic sequences of sixty human rotaviruses (all group A) and thirty-one porcine rotaviruses (thirteen group A, seven group B, six group C, and five group H). Phylogenetic analyses showed the co-circulation of multiple distinct RV group A (RVA) genotypes/strains, many of which were divergent from the strain components of licensed RVA vaccines, as well as considerable virus diversity in pigs including full genomes of rotaviruses in groups B, C, and H, none of which have been previously reported in Vietnam. Furthermore, the detection of an atypical RVA genotype constellation (G4-P[6]-I1-R1-C1-M1-A8-N1-T7-E1-H1) in a human patient and a pig from the same region provides some evidence for a zoonotic event.

Kumar P, Paton C, Kirigia D. 2016. I've got 99 problems but a phone ain't one: Electronic and mobile health in low and middle income countries. Arch Dis Child, 101 (10), pp. 974-979. | Show Abstract | Read more

Mobile technology is very prevalent in Kenya-mobile phone penetration is at 88% and mobile data subscriptions form 99% of all internet subscriptions. While there is great potential for such ubiquitous technology to revolutionise access and quality of healthcare in low-resource settings, there have been few successes at scale. Implementations of electronic health (e-Health) and mobile health (m-Health) technologies in countries like Kenya are yet to tackle human resource constraints or the political, ethical and financial considerations of such technologies. We outline recent innovations that could improve access and quality while considering the costs of healthcare. One is an attempt to create a scalable clinical decision support system by engaging a global network of specialist doctors and reversing some of the damaging effects of medical brain drain. The other efficiently extracts digital information from paper-based records using low-cost and locally produced tools such as rubber stamps to improve adherence to clinical practice guidelines. By bringing down the costs of remote consultations and clinical audit, respectively, these projects offer the potential for clinics in resource-limited settings to deliver high-quality care. This paper makes a case for continued and increased investment in social enterprises that bridge academia, public and private sectors to deliver sustainable and scalable e-Health and m-Health solutions.

Koh WM, Bogich T, Siegel K, Jin J, Chong EY, Tan CY, Chen MI, Horby P, Cook AR. 2016. The Epidemiology of Hand, Foot and Mouth Disease in Asia: A Systematic Review and Analysis. Pediatr Infect Dis J, 35 (10), pp. e285-e300. | Citations: 15 (Scopus) | Show Abstract | Read more

CONTEXT: Hand, foot and mouth disease (HFMD) is a widespread pediatric disease caused primarily by human enterovirus 71 (EV-A71) and Coxsackievirus A16 (CV-A16). OBJECTIVE: This study reports a systematic review of the epidemiology of HFMD in Asia. DATA SOURCES: PubMed, Web of Science and Google Scholar were searched up to December 2014. STUDY SELECTION: Two reviewers independently assessed studies for epidemiologic and serologic information about prevalence and incidence of HFMD against predetermined inclusion/exclusion criteria. DATA EXTRACTION: Two reviewers extracted answers for 8 specific research questions on HFMD epidemiology. The results are checked by 3 others. RESULTS: HFMD is found to be seasonal in temperate Asia with a summer peak and in subtropical Asia with spring and fall peaks, but not in tropical Asia; evidence of a climatic role was identified for temperate Japan. Risk factors for HFMD include hygiene, age, gender and social contacts, but most studies were underpowered to adjust rigorously for confounding variables. Both community-level and school-level transmission have been implicated, but their relative importance for HFMD is inconclusive. Epidemiologic indices are poorly understood: No supporting quantitative evidence was found for the incubation period of EV-A71; the symptomatic rate of EV-A71/Coxsackievirus A16 infection was from 10% to 71% in 4 studies; while the basic reproduction number was between 1.1 and 5.5 in 3 studies. The uncertainty in these estimates inhibits their use for further analysis. LIMITATIONS: Diversity of study designs complicates attempts to identify features of HFMD epidemiology. CONCLUSIONS: Knowledge on HFMD remains insufficient to guide interventions such as the incorporation of an EV-A71 vaccine in pediatric vaccination schedules. Research is urgently needed to fill these gaps.

Thuy DM, Peacock TP, Bich VTN, Fabrizio T, Hoang DN, Tho ND, Diep NT, Nguyen M, Hoa LNM, Trang HTT et al. 2016. Prevalence and diversity of H9N2 avian influenza in chickens of Northern Vietnam, 2014. Infect Genet Evol, 44 pp. 530-540. | Citations: 3 (Web of Science Lite) | Show Abstract | Read more

Despite their classification as low pathogenicity avian influenza viruses (LPAIV), A/H9N2 viruses cause significant losses in poultry in many countries throughout Asia, the Middle East and North Africa. To date, poultry surveillance in Vietnam has focused on detection of influenza H5 viruses, and there is limited understanding of influenza H9 epidemiology and transmission dynamics. We determined prevalence and diversity of influenza A viruses in chickens from live bird markets (LBM) of 7 northern Vietnamese provinces, using pooled oropharyngeal swabs collected from October to December 2014. Screening by real time RT-PCR revealed 1207/4900 (24.6%) of pooled swabs to be influenza A virus positive; overall prevalence estimates after accounting for pooling (5 swabs/pools) were 5.8% (CI 5.4-6.0). Subtyping was performed on 468 pooled swabs with M gene Ct<26. No influenza H7 was detected; 422 (90.1%) were H9 positive; and 22 (4.7%) were H5 positive. There was no evidence was of interaction between H9 and H5 virus detection rates. We sequenced 17 whole genomes of A/H9N2, 2 of A/H5N6, and 11 partial genomes. All H9N2 viruses had internal genes that clustered with genotype 57 and were closely related to Chinese human isolates of A/H7N9 and A/H10N8. Using a nucleotide divergence cutoff of 98%, we identified 9 distinct H9 genotypes. Phylogenetic analysis suggested multiple introductions of H9 viruses to northern Vietnam rather than in-situ transmission. Further investigations of H9 prevalence and diversity in other regions of Vietnam are warranted to assess H9 endemicity elsewhere in the country.

Paris DH, Dumler JS. 2016. State of the art of diagnosis of rickettsial diseases: the use of blood specimens for diagnosis of scrub typhus, spotted fever group rickettsiosis, and murine typhus. Curr Opin Infect Dis, 29 (5), pp. 433-439. | Citations: 5 (Scopus) | Show Abstract | Read more

PURPOSE OF REVIEW: With improved malaria control, acute undifferentiated febrile illness studies in tropical regions reveal a startling proportion of rickettsial illnesses, especially scrub typhus, murine typhus, and spotted fever group rickettsioses. Laboratory diagnosis of these infections evolved little over the past 40 years, but combinations of technologies like PCR and loop-mediated isothermal amplification, with refined rapid diagnostic tests and/or ELISA, are promising for guidance for early antirickettsial treatment. RECENT FINDINGS: The long-term reliance on serological tests - useful only late in rickettsial infections - has led to underdiagnosis, inappropriate therapies, and undocumented morbidity and mortality. Recent approaches integrate nucleic acid amplification and recombinant protein-based serological tests for diagnosing scrub typhus. Optimized using Bayesian latent class analyses, this strategy increases diagnostic confidence and enables early accurate diagnosis and treatment - a model to follow for lagging progress in murine typhus and spotted fever. SUMMARY: A laboratory diagnostic paradigm shift in rickettsial infections is evolving, with replacement of indirect immunofluorescence assay by the more objective ELISA coupled with nucleic acid amplification assays to expand the diagnostic window toward early infection intervals. This approach supports targeted antirickettsial therapy, reduces morbidity and mortality, and provides a robust evidence base for further development of diagnostics and vaccines.

Vanobberghen F, Penny MA, Duthaler U, Odermatt P, Sayasone S, Keiser J, Tarning J. 2016. Population Pharmacokinetic Modeling of Tribendimidine Metabolites in Opisthorchis viverrini-Infected Adults. Antimicrob Agents Chemother, 60 (10), pp. 5695-5704. | Citations: 1 (Web of Science Lite) | Show Abstract | Read more

There is a pressing need for alternative treatments against the liver fluke Opisthorchis viverrini Oral tribendimidine is a promising candidate, but its population pharmacokinetic properties are unknown. Two phase IIa trials were conducted in Laos in O. viverrini-infected adults receiving single oral doses of 25 to 600 mg tribendimidine administered as different formulations in each study (study 1 used 200-mg tablets, and study 2 used 50-mg tablets). Venous whole blood, plasma, and capillary dried blood spots were sampled frequently from 68 adults, and concentrations of the tribendimidine metabolites dADT (deacetylated amidantel) and adADT (acetylated dADT) were measured. Population pharmacokinetics were assessed by using nonlinear mixed-effects modeling. The relationship between drug exposure and cure (assessed at 21 days posttreatment) was evaluated by using univariable logistic regression. A six-transit compartment absorption model with a one-disposition compartment for each metabolite described the data well. Compared to the 50-mg formulation (study 2), the 200-mg formulation (study 1) had a 40.1% higher mean transit absorption time, a 113% higher dADT volume of distribution, and a 364% higher adADT volume of distribution. Each 10-year increase in age was associated with a 12.7% lower dADT clearance and a 21.2% lower adADT clearance. The highest cure rates (≥55%) were observed with doses of ≥100 mg. Higher dADT, but not adADT, peak concentrations and exposures were associated with cure (P = 0.004 and 0.003, respectively). For the first time, population pharmacokinetics of tribendimidine have been described. Known differences in the 200-mg versus 50-mg formulations were captured by covariate modeling. Further studies are needed to validate the structural model and confirm covariate relationships. (This study has been registered with the ISRCTN Registry under no. ISRCTN96948551.).

Chu CS, White NJ. 2016. Management of relapsing Plasmodium vivax malaria. Expert Rev Anti Infect Ther, 14 (10), pp. 885-900. | Citations: 7 (Scopus) | Show Abstract | Read more

INTRODUCTION: Relapses are important contributors to illness and morbidity in Plasmodium vivax and P. ovale infections. Relapse prevention (radical cure) with primaquine is required for optimal management, control and ultimately elimination of Plasmodium vivax malaria. A review was conducted with publications in English, French, Portuguese and Spanish using the search terms 'P. vivax' and 'relapse'. AREAS COVERED: Hypnozoites causing relapses may be activated weeks or months after initial infection. Incidence and temporal patterns of relapse varies geographically. Relapses derive from parasites either genetically similar or different from the primary infection indicating that some derive from previous infections. Malaria illness itself may activate relapse. Primaquine is the only widely available treatment for radical cure. However, it is often not given because of uncertainty over the risks of primaquine induced haemolysis when G6PD deficiency testing is unavailable. Recommended dosing of primaquine for radical cure in East Asia and Oceania is 0.5 mg base/kg/day and elsewhere is 0.25 mg base/kg/day. Alternative treatments are under investigation. Expert commentary: Geographic heterogeneity in relapse patterns and chloroquine susceptibility of P. vivax, and G6PD deficiency epidemiology mean that radical treatment should be given much more than it is today. G6PD testing should be made widely available so primaquine can be given more safely.

Basnyat B. 2016. Aftershocks of scrub typhus in Nepal - Author's reply. Lancet Glob Health, 4 (10), pp. e688. | Read more

Veringa A, van der Elst KCM, Day JN, Thwaites GE, Alffenaar J-WC. 2016. Sertraline for HIV-associated cryptococcal meningitis. Lancet Infect Dis, 16 (10), pp. 1111. | Read more

Montes de Oca M, Kumar R, Rivera FDL, Amante FH, Sheel M, Faleiro RJ, Bunn PT, Best SE, Beattie L, Ng SS et al. 2016. Type I Interferons Regulate Immune Responses in Humans with Blood-Stage Plasmodium falciparum Infection. Cell Rep, 17 (2), pp. 399-412. | Citations: 9 (Scopus) | Show Abstract | Read more

The development of immunoregulatory networks is important to prevent disease. However, these same networks allow pathogens to persist and reduce vaccine efficacy. Here, we identify type I interferons (IFNs) as important regulators in developing anti-parasitic immunity in healthy volunteers infected for the first time with Plasmodium falciparum. Type I IFNs suppressed innate immune cell function and parasitic-specific CD4+ T cell IFNγ production, and they promoted the development of parasitic-specific IL-10-producing Th1 (Tr1) cells. Type I IFN-dependent, parasite-specific IL-10 production was also observed in P. falciparum malaria patients in the field following chemoprophylaxis. Parasite-induced IL-10 suppressed inflammatory cytokine production, and IL-10 levels after drug treatment were positively associated with parasite burdens before anti-parasitic drug administration. These findings have important implications for understanding the development of host immune responses following blood-stage P. falciparum infection, and they identify type I IFNs and related signaling pathways as potential targets for therapies or vaccine efficacy improvement.

Cheah PY, Newton PN, Mayxay M. 2016. The first Science Café in Laos. Lancet, 388 (10052), pp. 1376. | Citations: 3 (Scopus) | Read more

Revell AD, Wang D, Wood R, Morrow C, Tempelman H, Hamers RL, Reiss P, van Sighem AI, Nelson M, Montaner JSG et al. 2016. An update to the HIV-TRePS system: the development and evaluation of new global and local computational models to predict HIV treatment outcomes, with or without a genotype. J Antimicrob Chemother, 71 (10), pp. 2928-2937. | Citations: 1 (Scopus) | Show Abstract | Read more

OBJECTIVES: Optimizing antiretroviral drug combination on an individual basis in resource-limited settings is challenging because of the limited availability of drugs and genotypic resistance testing. Here, we describe our latest computational models to predict treatment responses, with or without a genotype, and compare the potential utility of global and local models as a treatment tool for South Africa. METHODS: Global random forest models were trained to predict the probability of virological response to therapy following virological failure using 29 574 treatment change episodes (TCEs) without a genotype, 3179 of which were from South Africa and were used to develop local models. In addition, 15 130 TCEs including genotypes were used to develop another set of models. The 'no-genotype' models were tested with an independent global test set (n = 1700) plus a subset from South Africa (n = 222). The genotype models were tested with 750 independent cases. RESULTS: The global no-genotype models achieved area under the receiver-operating characteristic curve (AUC) values of 0.82 and 0.79 with the global and South African tests sets, respectively, and the South African models achieved AUCs of 0.70 and 0.79. The genotype models achieved an AUC of 0.84. The global no-genotype models identified more alternative, locally available regimens that were predicted to be effective for cases that failed their new regimen in the South African clinics than the local models. Both sets of models were significantly more accurate predictors of outcomes than genotyping with rules-based interpretation. CONCLUSIONS: These latest global models predict treatment responses accurately even without a genotype, out-performed the local South African models and have the potential to help optimize therapy, particularly in resource-limited settings.

Boender TS, Kityo CM, Boerma RS, Hamers RL, Ondoa P, Wellington M, Siwale M, Nankya I, Kaudha E, Akanmu AS et al. 2016. Accumulation of HIV-1 drug resistance after continued virological failure on first-line ART in adults and children in sub-Saharan Africa. J Antimicrob Chemother, 71 (10), pp. 2918-2927. | Citations: 7 (Scopus) | Show Abstract | Read more

OBJECTIVES: Limited availability of viral load (VL) monitoring in HIV treatment programmes in sub-Saharan Africa can delay switching to second-line ART, leading to the accumulation of drug resistance mutations (DRMs). The objective of this study was to evaluate the accumulation of resistance to reverse transcriptase inhibitors after continued virological failure on first-line ART, among adults and children in sub-Saharan Africa. METHODS: HIV-1-positive adults and children on an NNRTI-based first-line ART were included. Retrospective VL and, if VL ≥1000 copies/mL, pol genotypic testing was performed. Among participants with continued virological failure (≥2 VL ≥1000 copies/mL), drug resistance was evaluated. RESULTS: At first virological failure, DRM(s) were detected in 87% of participants: K103N (38.7%), G190A (21.8%), Y181C (20.2%), V106M (8.4%), K101E (8.4%), any E138 (7.6%) and V108I (7.6%) associated with NNRTIs, and M184V (69.7%), any thymidine analogue mutation (9.2%), K65R (5.9%) and K70R (5.0%) associated with NRTIs. New DRMs accumulated with an average rate of 1.45 (SD 2.07) DRM per year; 0.62 (SD 1.11) NNRTI DRMs and 0.84 (SD 1.38) NRTI DRMs per year, respectively. The predicted susceptibility declined significantly after continued virological failure for all reverse transcriptase inhibitors (all P < 0.001). Acquired drug resistance patterns were similar in adults and children. CONCLUSIONS: Patterns of drug resistance after virological failure on first-line ART are similar in adults and children in sub-Saharan Africa. Improved VL monitoring to prevent accumulation of mutations, and new drug classes to construct fully active regimens, are required.

Mcgready R, Turner C, Rijken M, Wong N, Salisbury P, Chandra A, Nosten F, Bendell B, Moore K, Sneddon A. 2016. Impact of ALSO (R) Australasia on PPH-Related Maternal Mortality on the Thailand-Myanmar Border in a Population Based Cohort Study AUSTRALIAN & NEW ZEALAND JOURNAL OF OBSTETRICS & GYNAECOLOGY, 56 pp. 24-25.

Cheah PY, Newton PN, Mayxay M. 2016. The first Science Cafe in Laos LANCET, 388 (10052), pp. 1376-1376. | Citations: 2 (Web of Science Lite) | Read more

Grijsen ML, Kaderbhai HS, Hamers RL, Masenga JE. 2016. Under fire in Tanzania Nederlands Tijdschrift voor Dermatologie en Venereologie, 26 (9), pp. 538-541.

Barasa EW, Cleary S, English M, Molyneux S. 2016. The influence of power and actor relations on priority setting and resource allocation practices at the hospital level in Kenya: a case study. BMC Health Serv Res, 16 (1), pp. 536. | Citations: 2 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Priority setting and resource allocation in healthcare organizations often involves the balancing of competing interests and values in the context of hierarchical and politically complex settings with multiple interacting actor relationships. Despite this, few studies have examined the influence of actor and power dynamics on priority setting practices in healthcare organizations. This paper examines the influence of power relations among different actors on the implementation of priority setting and resource allocation processes in public hospitals in Kenya. METHODS: We used a qualitative case study approach to examine priority setting and resource allocation practices in two public hospitals in coastal Kenya. We collected data by a combination of in-depth interviews of national level policy makers, hospital managers, and frontline practitioners in the case study hospitals (n = 72), review of documents such as hospital plans and budgets, minutes of meetings and accounting records, and non-participant observations in case study hospitals over a period of 7 months. We applied a combination of two frameworks, Norman Long's actor interface analysis and VeneKlasen and Miller's expressions of power framework to examine and interpret our findings RESULTS: The interactions of actors in the case study hospitals resulted in socially constructed interfaces between: 1) senior managers and middle level managers 2) non-clinical managers and clinicians, and 3) hospital managers and the community. Power imbalances resulted in the exclusion of middle level managers (in one of the hospitals) and clinicians and the community (in both hospitals) from decision making processes. This resulted in, amongst others, perceptions of unfairness, and reduced motivation in hospital staff. It also puts to question the legitimacy of priority setting processes in these hospitals. CONCLUSIONS: Designing hospital decision making structures to strengthen participation and inclusion of relevant stakeholders could improve priority setting practices. This should however, be accompanied by measures to empower stakeholders to contribute to decision making. Strengthening soft leadership skills of hospital managers could also contribute to managing the power dynamics among actors in hospital priority setting processes.

Barasa EW, Cleary S, English M, Molyneux S. 2016. The influence of power and actor relations on priority setting and resource allocation practices at the hospital level in Kenya: a case study BMC health services research, 16 (1), pp. 536. | Show Abstract

BACKGROUND: Priority setting and resource allocation in healthcare organizations often involves the balancing of competing interests and values in the context of hierarchical and politically complex settings with multiple interacting actor relationships. Despite this, few studies have examined the influence of actor and power dynamics on priority setting practices in healthcare organizations. This paper examines the influence of power relations among different actors on the implementation of priority setting and resource allocation processes in public hospitals in Kenya. METHODS: We used a qualitative case study approach to examine priority setting and resource allocation practices in two public hospitals in coastal Kenya. We collected data by a combination of in-depth interviews of national level policy makers, hospital managers, and frontline practitioners in the case study hospitals (n = 72), review of documents such as hospital plans and budgets, minutes of meetings and accounting records, and non-participant observations in case study hospitals over a period of 7 months. We applied a combination of two frameworks, Norman Long's actor interface analysis and VeneKlasen and Miller's expressions of power framework to examine and interpret our findings RESULTS: The interactions of actors in the case study hospitals resulted in socially constructed interfaces between: 1) senior managers and middle level managers 2) non-clinical managers and clinicians, and 3) hospital managers and the community. Power imbalances resulted in the exclusion of middle level managers (in one of the hospitals) and clinicians and the community (in both hospitals) from decision making processes. This resulted in, amongst others, perceptions of unfairness, and reduced motivation in hospital staff. It also puts to question the legitimacy of priority setting processes in these hospitals. CONCLUSIONS: Designing hospital decision making structures to strengthen participation and inclusion of relevant stakeholders could improve priority setting practices. This should however, be accompanied by measures to empower stakeholders to contribute to decision making. Strengthening soft leadership skills of hospital managers could also contribute to managing the power dynamics among actors in hospital priority setting processes.

Bard E, Knight M, Plugge E. 2016. Perinatal health care services for imprisoned pregnant women and associated outcomes: a systematic review. BMC Pregnancy Childbirth, 16 (1), pp. 285. | Citations: 3 (Scopus) | Show Abstract | Read more

BACKGROUND: Women are an increasing minority of prisoners worldwide, and most are of childbearing age. Prisons offer unique opportunities for improving the pregnancy outcomes of these high-risk women, and no systematic review to date has looked at their care. This systematic review identified studies describing models of perinatal health care for imprisoned women which report maternal and child health and care outcomes. METHODS: We systematically searched for literature published between 1980 and April 2014. Studies were eligible if they included a group of imprisoned pregnant women, a description of perinatal health care and any maternal or infant health or care outcomes. Two authors independently extracted data. We described relevant outcomes in prisons (including jails) under models of care we termed PRISON, PRISON+ and PRISON++, depending on the care provided. Where outcomes were available on a comparison group of women, we calculated odds ratios with 95 % confidence intervals. RESULTS: Eighteen studies were reported, comprising 2001 imprisoned pregnant women. Fifteen were in the US, two in the UK and one in Germany. Nine contained a comparison group of women comprising 849 pregnant women. Study quality was variable and outcome reporting was inconsistent. There was some evidence that women in prisons receiving enhanced prison care, PRISON+, were less likely to have inadequate prenatal care (15.4 % vs 30.7 %, p < 0 · 001), preterm delivery (6.4 % vs 19.0 %, p = 0 · 001) or caesarean delivery (12.9 % vs 26.5 %, p = 0 · 005) compared to women in prisons receiving usual care (PRISON). Women participating in two PRISON++ interventions, that is, interventions which included not only enhanced care in prisons but also coordination of community care on release, demonstrated reductions in long term recidivism rates (summary OR 0 · 37, 95 % CI 0 · 19-0 · 70) compared to pregnant women in the same prisons who did not participate in the intervention. CONCLUSIONS: Enhanced perinatal care can improve both short and long-term outcomes but there is a lack of data. Properly designed programmes with rigorous evaluation are needed to address the needs of this vulnerable population. The cost to mothers, children and to society of failing to address these important public health issues are likely to be substantial. TRIAL REGISTRATION: PROSPERO registration: CRD42012002384 .

Bernier MC, Li F, Musselman B, Newton PN, Fernandez FM. 2016. Fingerprinting of falsified artemisinin combination therapies via direct analysis in real time coupled to a compact single quadrupole mass spectrometer ANALYTICAL METHODS, 8 (36), pp. 6616-6624. | Citations: 2 (Web of Science Lite) | Show Abstract | Read more

© The Royal Society of Chemistry 2016. Falsified anti-malarial treatments continue to constitute a major health crisis, especially in malarious Africa. Even after detection of poor quality pharmaceuticals, it is critical that they be fully analyzed to determine their components, in order to assess their health effects and ultimately allow forensic tracing of their sources of production and distribution. Timely assessment requires robust and complete field-testing, or at the very least timely analysis after seizure or purchase. Ideally, low-cost and simple analytical equipment such as portable mass spectrometry (MS) is the best approach for achieving this quick and informative analysis. To date, Direct Analysis in Real Time (DART) MS has been successfully implemented to rapidly analyze falsified artemisinin-based combination therapies (ACTs) in laboratory settings, but this approach typically translates into high-cost and the need for high-resolution instrumentation. Here, we examine the use of DART ionization coupled with a portable low-resolution single-quadrupole instrument, and compare its success in fingerprinting anti-malarial tablets with higher resolution instrumentation. Using single quadrupole DART-MS, the same sample components were detected as with the high-resolution instrument, while needing significantly less consumables and power, and the additional advantages of increased portability and ease of use. Using Principal Component Analysis (PCA) of DART data, specific classes of falsified ACTs were identified, providing a more straightforward method for sourcing counterfeits and assessing their similarities.

Kajeechiwa L, Thwin MM, Shee PW, Yee NL, Elvina E, Peapah P, Kyawt K, Oo PT, PoWah W, Min JR et al. 2016. The acceptability of mass administrations of anti-malarial drugs as part of targeted malaria elimination in villages along the Thai-Myanmar border. Malar J, 15 (1), pp. 494. | Citations: 10 (Scopus) | Show Abstract | Read more

BACKGROUND: A targeted malaria elimination project, including mass drug administrations (MDA) of dihydroartemisinin/piperaquine plus a single low dose primaquine is underway in villages along the Thailand Myanmar border. The intervention has multiple components but the success of the project will depend on the participation of the entire communities. Quantitative surveys were conducted to study reasons for participation or non-participation in the campaign with the aim to identify factors associated with the acceptance and participation in the mass drug administrations. METHODS: The household heads in four study villages in which MDAs had taken place previously were interviewed between January 2014 and July 2015. RESULTS: 174/378 respondents (46 %) completed three rounds of three drug doses each, 313/378 (83 %) took at least three consecutive doses and 56/378 (15 %) did not participate at all in the MDA. The respondents from the two villages (KNH and TPN) were much more likely to participate in the MDA than respondents from the other two villages (HKT and TOT). The more compliant villages KNH and TPN had both an appearance of cohesive communities with similar demographic and ethnic backgrounds. By contrast the villages with low participation were unique. One village was fragmented following years of armed conflict and many respondents gave little inclination to cooperate with outsiders. The other village with low MDA coverage was characterised by a high percentage of short-term residents with little interest in community interventions. A universal reason for non-participation in the MDA applicable to all villages was an inadequate understanding of the intervention. CONCLUSIONS: It is unlikely that community engagement can unite fragmented communities in participating in an intervention, which benefits the community. Understanding the purpose and the reasons underlying the intervention is an important pre-condition for participation. In the absence of direct benefits and a complete understanding of the indirect benefits trust in the investigators is critical for participation.

Edgcombe H, Paton C, English M. 2016. Enhancing emergency care in low-income countries using mobile technology-based training tools. Arch Dis Child, 101 (12), pp. 1149-1152. | Citations: 2 (Web of Science Lite) | Show Abstract | Read more

In this paper, we discuss the role of mobile technology in developing training tools for health workers, with particular reference to low-income countries (LICs). The global and technological context is outlined, followed by a summary of approaches to using and evaluating mobile technology for learning in healthcare. Finally, recommendations are made for those developing and using such tools, based on current literature and the authors' involvement in the field.

International Typhoid Consortium, Wong VK, Holt KE, Okoro C, Baker S, Pickard DJ, Marks F, Page AJ, Olanipekun G, Munir H et al. 2016. Molecular Surveillance Identifies Multiple Transmissions of Typhoid in West Africa. PLoS Negl Trop Dis, 10 (9), pp. e0004781. | Citations: 1 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: The burden of typhoid in sub-Saharan African (SSA) countries has been difficult to estimate, in part, due to suboptimal laboratory diagnostics. However, surveillance blood cultures at two sites in Nigeria have identified typhoid associated with Salmonella enterica serovar Typhi (S. Typhi) as an important cause of bacteremia in children. METHODS: A total of 128 S. Typhi isolates from these studies in Nigeria were whole-genome sequenced, and the resulting data was used to place these Nigerian isolates into a worldwide context based on their phylogeny and carriage of molecular determinants of antibiotic resistance. RESULTS: Several distinct S. Typhi genotypes were identified in Nigeria that were related to other clusters of S. Typhi isolates from north, west and central regions of Africa. The rapidly expanding S. Typhi clade 4.3.1 (H58) previously associated with multiple antimicrobial resistances in Asia and in east, central and southern Africa, was not detected in this study. However, antimicrobial resistance was common amongst the Nigerian isolates and was associated with several plasmids, including the IncHI1 plasmid commonly associated with S. Typhi. CONCLUSIONS: These data indicate that typhoid in Nigeria was established through multiple independent introductions into the country, with evidence of regional spread. MDR typhoid appears to be evolving independently of the haplotype H58 found in other typhoid endemic countries. This study highlights an urgent need for routine surveillance to monitor the epidemiology of typhoid and evolution of antimicrobial resistance within the bacterial population as a means to facilitate public health interventions to reduce the substantial morbidity and mortality of typhoid.

Bediako Y, Ngoi JM, Nyangweso G, Wambua J, Opiyo M, Nduati EW, Bejon P, Marsh K, Ndungu FM. 2016. The effect of declining exposure on T cell-mediated immunity to Plasmodium falciparum - an epidemiological "natural experiment". BMC Med, 14 (1), pp. 143. | Citations: 2 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Naturally acquired immunity to malaria may be lost with lack of exposure. Recent heterogeneous reductions in transmission in parts of Africa mean that large populations of previously protected people may lose their immunity while remaining at risk of infection. METHODS: Using two ethnically similar long-term cohorts of children with historically similar levels of exposure to Plasmodium falciparum who now experience very different levels of exposure, we assessed the effect of decreased parasite exposure on antimalarial immunity. Peripheral blood mononuclear cells (PBMCs) from children in each cohort were stimulated with P. falciparum and their P. falciparum-specific proliferative and cytokine responses were compared. RESULTS: We demonstrate that, while P. falciparum-specific CD4+ T cells are maintained in the absence of exposure, the proliferative capacity of these cells is altered considerably. P. falciparum-specific CD4+ T cells isolated from children previously exposed, but now living in an area of minimal exposure ("historically exposed") proliferate significantly more upon stimulation than cells isolated from children continually exposed to the parasite. Similarly, PBMCs from historically exposed children expressed higher levels of pro-inflammatory cytokines and lower levels of anti-inflammatory cytokines after stimulation with P. falciparum. Notably, we found a significant positive association between duration since last febrile episode and P. falciparum-specific CD4+ T cell proliferation, with more recent febrile episodes associated with lower proliferation. CONCLUSION: Considered in the context of existing knowledge, these data suggest a model explaining how immunity is lost in absence of continuing exposure to P. falciparum.

Sahl JW, Vazquez AJ, Hall CM, Busch JD, Tuanyok A, Mayo M, Schupp JM, Lummis M, Pearson T, Shippy K et al. 2016. The Effects of Signal Erosion and Core Genome Reduction on the Identification of Diagnostic Markers. MBio, 7 (5), pp. e00846-16-e00846-16. | Citations: 3 (Scopus) | Show Abstract | Read more

UNLABELLED: Whole-genome sequence (WGS) data are commonly used to design diagnostic targets for the identification of bacterial pathogens. To do this effectively, genomics databases must be comprehensive to identify the strict core genome that is specific to the target pathogen. As additional genomes are analyzed, the core genome size is reduced and there is erosion of the target-specific regions due to commonality with related species, potentially resulting in the identification of false positives and/or false negatives. IMPORTANCE: A comparative analysis of 1,130 Burkholderia genomes identified unique markers for many named species, including the human pathogens B. pseudomallei and B. mallei Due to core genome reduction and signature erosion, only 38 targets specific to B. pseudomallei/mallei were identified. By using only public genomes, a larger number of markers were identified, due to undersampling, and this larger number represents the potential for false positives. This analysis has implications for the design of diagnostics for other species where the genomic space of the target and/or closely related species is not well defined.

Poovorawan K, Pan-Ngum W, White LJ, Soonthornworasiri N, Wilairatana P, Wasitthankasem R, Tangkijvanich P, Poovorawan Y. 2016. Estimating the Impact of Expanding Treatment Coverage and Allocation Strategies for Chronic Hepatitis C in a Direct Antiviral Agent Era. PLoS One, 11 (9), pp. e0163095. | Citations: 2 (Scopus) | Show Abstract | Read more

Hepatitis C virus (HCV) infection is an important worldwide public health problem, and most of the global HCV burden is in low- to middle-income countries. This study aimed to estimate the future burden of chronic hepatitis C (CHC) and the impact of public health policies using novel antiviral agents in Thailand. A mathematical model of CHC transmission dynamics was constructed to examine the disease burden over the next 20 years using different treatment strategies. We compared and evaluated the current treatment (PEGylated interferon and ribavirin) with new treatments using novel direct-acting antiviral agents among various treatment policies. Thailand's CHC prevalence was estimated to decrease 1.09%-0.19% in 2015-2035. Expanding treatment coverage (i.e., a five-fold increment in treatment accessibility) was estimated to decrease cumulative deaths (33,007 deaths avoided, 25.5% reduction) from CHC-related decompensated cirrhosis and hepatocellular carcinoma (HCC). The yearly incidence of HCC-associated HCV was estimated to decrease from 2,305 to 1,877 cases yearly with expanding treatment coverage. A generalized treatment scenario (i.e., an equal proportional distribution of available treatment to individuals at all disease stages according to the number of cases at each stage) was predicted to further reduce death from HCC (9,170 deaths avoided, 11.3% reduction) and the annual incidence of HCC (i.e., a further decrease from 1,877 to 1,168 cases yearly, 37.7% reduction), but cumulative deaths were predicted to increase (by 3,626 deaths, 3.7% increase). Based on the extensive coverage scenario and the generalized treatment scenario, we estimated near-zero death from decompensated cirrhosis in 2031. In conclusion, CHC-related morbidity and mortality in Thailand are estimated to decrease dramatically over the next 20 years. Treatment coverage and allocation strategies are important factors that affect the future burden of CHC in resource-limited countries like Thailand.

Fellmeth G, Oo MM, Lay B, McGready R. 2016. Paired suicide in a young refugee couple on the Thai-Myanmar border. BMJ Case Rep, 2016 pp. bcr2016215527-bcr2016215527. | Show Abstract | Read more

A young refugee woman attended antenatal clinic on the Thai-Myanmar border at 9 weeks' gestation. As part of an ongoing study of perinatal mental health, she underwent a structured psychiatric interview during which she described occasional depressed mood, anhedonia and passive suicidal ideation. Her husband was a young refugee known to use alcohol and drugs. 2 days later, the couple committed suicide together by herbicide ingestion. Refugee populations are at risk of developing mental disorders as a result of their marginalised status, socioeconomic disadvantage and exposures to trauma. Pregnancy may have exacerbated feelings of hopelessness in this couple. The prevalence of mental disorders such as depression is increased in the perinatal period and suicide is the second leading cause of death in young women globally. Prevention programmes and early recognition of mental disorders may improve detection and lead to better support for vulnerable individuals.

Boender TS, Hamers RL, Ondoa P, Wellington M, Chimbetete C, Siwale M, Labib Maksimos EEF, Balinda SN, Kityo CM, Adeyemo TA et al. 2016. Protease Inhibitor Resistance in the First 3 Years of Second-Line Antiretroviral Therapy for HIV-1 in Sub-Saharan Africa. J Infect Dis, 214 (6), pp. 873-883. | Citations: 7 (Scopus) | Show Abstract | Read more

BACKGROUND: As antiretroviral therapy (ART) programs in sub-Saharan Africa mature, increasing numbers of persons with human immunodeficiency virus (HIV) infection will experience treatment failure, and require second- or third-line ART. Data on second-line failure and development of protease inhibitor (PI) resistance in sub-Saharan Africa are scarce. METHODS: HIV-1-infected adults were included if they received >180 days of PI-based second-line ART. We assessed risk factors for having a detectable viral load (VL, ≥400 cps/mL) using Cox models. If VL was ≥1000 cps/mL, genotyping was performed. RESULTS: Of 227 included participants, 14.6%, 15.2% and 11.1% had VLs ≥400 cps/mL at 12, 24, and 36 months, respectively. Risk factors for a detectable VL were as follows: exposure to nonstandard nonnucleoside reverse-transcriptase inhibitor (NNRTI)-based (hazard ratio, 7.10; 95% confidence interval, 3.40-14.83; P < .001) or PI-based (7.59; 3.02-19.07; P = .001) first-line regimen compared with zidovudine/lamivudine/NNRTI, PI resistance at switch (6.69; 2.49-17.98; P < .001), and suboptimal adherence (3.05; 1.71-5.42; P = .025). Among participants with VLs ≥1000 cps/mL, 22 of 32 (69%) harbored drug resistance mutation(s), and 7 of 32 (22%) harbored PI resistance. CONCLUSIONS: Although VL suppression rates were high, PI resistance was detected in 22% of participants with VLs ≥1000 cps/mL. To ensure long-term ART success, intensified support for adherence, VL and drug resistance testing, and third-line drugs will be necessary.

Cheah PY, Parker M, Dondorp AM. 2016. Development of drugs for severe malaria in children. Int Health, 8 (5), pp. 313-316. | Citations: 2 (Web of Science Lite) | Show Abstract | Read more

Over 90% of deaths attributable to malaria are in African children under 5 years old. Yet, new treatments are often tested primarily in adult patients and extrapolations have proven to be sometimes invalid, especially in dosing regimens. For studies in severe malaria an additional complication is that the decline in severe malaria in adult patients precludes sufficiently powered trials in adults, before the intervention can be tested in the ultimate target group, paediatric severe malaria. In this paper we propose an alternative pathway to the development of drugs for use in paediatric severe malaria. We argue that following the classical phase I and II studies, small safety and efficacy studies using well-chosen surrogate endpoints in adult severe malaria be conducted, instead of larger mortality endpoint trials. If the drug appears safe and promising small pilot studies in paediatric severe malaria using the same endpoints can follow. Finally, with carefully observed safeguards in place to ensure high ethical standards, promising candidate interventions can be taken forward into mortality endpoint, well-powered, large paediatric studies in African children with severe malaria. Given the available research capacity, limited numbers of prudently selected interventions can be studied in phase III trials, and adaptive designs should be considered.

Trung NV, Nhung HN, Carrique-Mas JJ, Mai HH, Tuyen HT, Campbell J, Nhung NT, Van Minh P, Wagenaar JA, Mai NTN et al. 2016. Colonization of Enteroaggregative Escherichia coli and Shiga toxin-producing Escherichia coli in chickens and humans in southern Vietnam. BMC Microbiol, 16 (1), pp. 208. | Show Abstract | Read more

BACKGROUND: Enteroaggregative (EAEC) and Shiga-toxin producing Escherichia coli (STEC) are a major cause of diarrhea worldwide. E. coli carrying both virulence factors characteristic for EAEC and STEC and producing extended-spectrum beta-lactamase caused severe and protracted disease during an outbreak of E. coli O104:H4 in Europe in 2011. We assessed the opportunities for E. coli carrying the aggR and stx genes to emerge in 'backyard' farms in south-east Asia. RESULTS: Faecal samples collected from 204 chicken farms; 204 farmers and 306 age- and gender-matched individuals not exposed to poultry farming were plated on MacConkey agar plates with and without antimicrobials being supplemented. Sweep samples obtained from MacConkey agar plates without supplemented antimicrobials were screened by multiplex PCR for the detection of the stx1, stx2 and aggR genes. One chicken farm sample each (0.5 %) contained the stx1 and the aggR gene. Eleven (2.4 %) human faecal samples contained the stx1 gene, 2 samples (0.4 %) contained stx2 gene, and 31 (6.8 %) contained the aggR gene. From 46 PCR-positive samples, 205 E. coli isolates were tested for the presence of stx1, stx2, aggR, wzx O104 and fliC H4 genes. None of the isolates simultaneously contained the four genetic markers associated with E. coli O104:H4 epidemic strain (aggR, stx2, wzx O104 and fliC H4 ). Of 34 EAEC, 64.7 % were resistant to 3(rd)-generation cephalosporins. CONCLUSION: These results indicate that in southern Vietnam, the human population is a more likely reservoir of aggR and stx gene carrying E. coli than the chicken population. However, conditions for transmission of isolates and/or genes between human and animal reservoirs resulting in the emergence of highly virulent E. coli strains are still favorable, given the nature of'backyard' farms in Vietnam.

Attia S, Versloot CJ, Voskuijl W, van Vliet SJ, Di Giovanni V, Zhang L, Richardson S, Bourdon C, Netea MG, Berkley JA et al. 2016. Mortality in children with complicated severe acute malnutrition is related to intestinal and systemic inflammation: an observational cohort study. Am J Clin Nutr, 104 (5), pp. 1441-1449. | Citations: 8 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Diarrhea affects a large proportion of children with severe acute malnutrition (SAM). However, its etiology and clinical consequences remain unclear. OBJECTIVE: We investigated diarrhea, enteropathogens, and systemic and intestinal inflammation for their interrelation and their associations with mortality in children with SAM. DESIGN: Intestinal pathogens (n = 15), cytokines (n = 29), fecal calprotectin, and the short-chain fatty acids (SCFAs) butyrate and propionate were determined in children aged 6-59 mo (n = 79) hospitalized in Malawi for complicated SAM. The relation between variables, diarrhea, and death was assessed with partial least squares (PLS) path modeling. RESULTS: Fatal subjects (n = 14; 18%) were younger (mean ± SD age: 17 ± 11 compared with 25 ± 11 mo; P = 0.01) with higher prevalence of diarrhea (46% compared with 18%, P = 0.03). Intestinal pathogens Shigella (36%), Giardia (33%), and Campylobacter (30%) predominated, but their presence was not associated with death or diarrhea. Calprotectin was significantly higher in children who died [median (IQR): 1360 mg/kg feces (2443-535 mg/kg feces) compared with 698 mg/kg feces (1438-244 mg/kg feces), P = 0.03]. Butyrate [median (IQR): 31 ng/mL (112-22 ng/mL) compared with 2036 ng/mL (5800-149 ng/mL), P = 0.02] and propionate [median (IQR): 167 ng/mL (831-131 ng/mL) compared with 3174 ng/mL (5819-357 ng/mL), P = 0.04] were lower in those who died. Mortality was directly related to high systemic inflammation (path coefficient = 0.49), whereas diarrhea, high calprotectin, and low SCFA production related to death indirectly via their more direct association with systemic inflammation. CONCLUSIONS: Diarrhea, high intestinal inflammation, low concentrations of fecal SCFAs, and high systemic inflammation are significantly related to mortality in SAM. However, these relations were not mediated by the presence of intestinal pathogens. These findings offer an important understanding of inflammatory changes in SAM, which may lead to improved therapies. This trial was registered at as ISRCTN13916953.

Weitzel T, Dittrich S, López J, Phuklia W, Martinez-Valdebenito C, Velásquez K, Blacksell SD, Paris DH, Abarca K. 2016. Endemic Scrub Typhus in South America. N Engl J Med, 375 (10), pp. 954-961. | Citations: 13 (Web of Science Lite) | Show Abstract | Read more

Scrub typhus is a life-threatening zoonosis caused by Orientia tsutsugamushi organisms that are transmitted by the larvae of trombiculid mites. Endemic scrub typhus was originally thought to be confined to the so called "tsutsugamushi triangle" within the Asia-Pacific region. In 2006, however, two individual cases were detected in the Middle East and South America, which suggested that the pathogen was present farther afield. Here, we report three autochthonous cases of scrub typhus caused by O. tsutsugamushi acquired on Chiloé Island in southern Chile, which suggests the existence of an endemic focus in South America. (Funded by the Chilean Comisión Nacional de Investigación Científica y Tecnológica and the Wellcome Trust.).

Hassan KA, Cain AK, Huang T, Liu Q, Elbourne LDH, Boinett CJ, Brzoska AJ, Li L, Ostrowski M, Nhu NTK et al. 2016. Fluorescence-Based Flow Sorting in Parallel with Transposon Insertion Site Sequencing Identifies Multidrug Efflux Systems in Acinetobacter baumannii. MBio, 7 (5), pp. e01200-16-e01200-16. | Show Abstract | Read more

UNLABELLED: Multidrug efflux pumps provide clinically significant levels of drug resistance in a number of Gram-negative hospital-acquired pathogens. These pathogens frequently carry dozens of genes encoding putative multidrug efflux pumps. However, it can be difficult to determine how many of these pumps actually mediate antimicrobial efflux, and it can be even more challenging to identify the regulatory proteins that control expression of these pumps. In this study, we developed an innovative high-throughput screening method, combining transposon insertion sequencing and cell sorting methods (TraDISort), to identify the genes encoding major multidrug efflux pumps, regulators, and other factors that may affect the permeation of antimicrobials, using the nosocomial pathogen Acinetobacter baumannii A dense library of more than 100,000 unique transposon insertion mutants was treated with ethidium bromide, a common substrate of multidrug efflux pumps that is differentially fluorescent inside and outside the bacterial cytoplasm. Populations of cells displaying aberrant accumulations of ethidium were physically enriched using fluorescence-activated cell sorting, and the genomic locations of transposon insertions within these strains were determined using transposon-directed insertion sequencing. The relative abundance of mutants in the input pool compared to the selected mutant pools indicated that the AdeABC, AdeIJK, and AmvA efflux pumps are the major ethidium efflux systems in A. baumannii Furthermore, the method identified a new transcriptional regulator that controls expression of amvA In addition to the identification of efflux pumps and their regulators, TraDISort identified genes that are likely to control cell division, cell morphology, or aggregation in A. baumannii IMPORTANCE: Transposon-directed insertion sequencing (TraDIS) and related technologies have emerged as powerful methods to identify genes required for bacterial survival or competitive fitness under various selective conditions. We applied fluorescence-activated cell sorting (FACS) to physically enrich for phenotypes of interest within a mutant population prior to TraDIS. To our knowledge, this is the first time that a physical selection method has been applied in parallel with TraDIS rather than a fitness-induced selection. The results demonstrate the feasibility of this combined approach to generate significant results and highlight the major multidrug efflux pumps encoded in an important pathogen. This FACS-based approach, TraDISort, could have a range of future applications, including the characterization of efflux pump inhibitors, the identification of regulatory factors controlling gene or protein expression using fluorescent reporters, and the identification of genes involved in cell replication, morphology, and aggregation.

Lim C, Takahashi E, Hongsuwan M, Wuthiekanun V, Thamlikitkul V, Hinjoy S, Day NP, Peacock SJ, Limmathurotsakul D. 2016. Epidemiology and burden of multidrug-resistant bacterial infection in a developing country. Elife, 5 (September), | Citations: 7 (Web of Science Lite) | Show Abstract | Read more

Little is known about the excess mortality caused by multidrug-resistant (MDR) bacterial infection in low- and middle-income countries (LMICs). We retrospectively obtained microbiology laboratory and hospital databases of nine public hospitals in northeast Thailand from 2004 to 2010, and linked these with the national death registry to obtain the 30-day mortality outcome. The 30-day mortality in those with MDR community-acquired bacteraemia, healthcare-associated bacteraemia, and hospital-acquired bacteraemia were 35% (549/1555), 49% (247/500), and 53% (640/1198), respectively. We estimate that 19,122 of 45,209 (43%) deaths in patients with hospital-acquired infection due to MDR bacteria in Thailand in 2010 represented excess mortality caused by MDR. We demonstrate that national statistics on the epidemiology and burden of MDR in LMICs could be improved by integrating information from readily available databases. The prevalence and mortality attributable to MDR in Thailand are high. This is likely to reflect the situation in other LMICs.

Otienoburu SD, Maïga-Ascofaré O, Schramm B, Jullien V, Jones JJ, Zolia YM, Houzé P, Ashley EA, Kiechel J-R, Guérin PJ et al. 2016. Selection of Plasmodium falciparum pfcrt and pfmdr1 polymorphisms after treatment with artesunate-amodiaquine fixed dose combination or artemether-lumefantrine in Liberia. Malar J, 15 (1), pp. 452. | Citations: 1 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Plasmodium falciparum uncomplicated malaria can successfully be treated with an artemisinin-based combination therapy (ACT). However resistance is spreading to the different ACT compounds; the artemisinin derivative and the partner drug. Studies of P. falciparum polymorphisms associated with drug resistance can provide a useful tool to track resistance and guide treatment policy as well as an in-depth understanding of the development and spread of resistance. METHODS: The role of P. falciparum molecular markers in selection of reinfections was assessed in an efficacy trial comparing artesunate-amodiaquine fixed-dose combination with artemether-lumefantrine to treat malaria in Nimba County, Liberia 2008-2009. P. falciparum polymorphisms in pfcrt 76, pfmdr1 86, 184 and 1246, and pfmrp1 876 and 1466 were analysed by PCR-RFLP and pyrosequencing. RESULTS: High baseline prevalence of pfmdr1 1246Y was found in Nimba county (38 %). Pfmdr1 1246Y and pfmdr1 86+184+1246 haplotypes NYY and YYY were selected in reinfections in the artesunate-amodiaquine arm and pfcrt K76, pfmdr1 N86 and pfmdr1 haplotype NFD were selected in artemether-lumefantrine reinfections. Parasites harbouring pfmdr1 1246Y could reinfect earlier after treatment with artesunate-amodiaquine and parasites carrying pfmdr1 N86 could reinfect at higher lumefantrine concentrations in patients treated with artemether-lumefantrine. CONCLUSIONS: Although treatment is highly efficacious, selection of molecular markers in reinfections could indicate a decreased sensitivity or tolerance of parasites to the current treatments and the baseline prevalence of molecular markers should be closely monitored. Since individual drug levels and the day of reinfection were demonstrated to be key determinants for selection of reinfections, this data needs to be collected and taken into account for accurate evaluation of molecular markers for anti-malarial treatments. The protocols for the clinical trial was registered with Current Controlled Trials, under the Identifier Number ISRCTN51688713 on 9 October 2008.

Yacoub S, Lam PK, Vu LHM, Le TL, Ha NT, Toan TT, Van NT, Quyen NTH, Le Duyen HT, Van Kinh N et al. 2016. Association of Microvascular Function and Endothelial Biomarkers With Clinical Outcome in Dengue: An Observational Study. J Infect Dis, 214 (5), pp. 697-706. | Citations: 8 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: The hallmark of severe dengue is increased microvascular permeability, but alterations in the microcirculation and their evolution over the course of dengue are unknown. METHODS: We conducted a prospective observational study to evaluate the sublingual microcirculation using side-stream dark-field imaging in patients presenting early (<72 hours after fever onset) and patients hospitalized with warning signs or severe dengue in Vietnam. Clinical findings, microvascular function, global hemodynamics assessed with echocardiography, and serological markers of endothelial activation were determined at 4 time points. RESULTS: A total of 165 patients were enrolled. No difference was found between the microcirculatory parameters comparing dengue with other febrile illnesses. The proportion of perfused vessels (PPV) and the mean flow index (MFI) were lower in patients with dengue with plasma than those without leakage (PPV, 88.1% vs 90.6% [P = .01]; MFI, 2.1 vs 2.4 [P = .007]), most markedly during the critical phase. PPV and MFI were correlated with the endothelial activation markers vascular cell adhesion molecule 1 (P < .001 for both) and angiopoietin 2 (P < .001 for both), negatively correlated. CONCLUSIONS: Modest microcirculatory alterations occur in dengue, are associated with plasma leakage, and are correlate with molecules of endothelial activation, angiopoietin 2 and vascular cell adhesion molecule 1.

Phyo AP, Ashley EA, Anderson TJC, Bozdech Z, Carrara VI, Sriprawat K, Nair S, White MM, Dziekan J, Ling C et al. 2016. Declining Efficacy of Artemisinin Combination Therapy Against P. Falciparum Malaria on the Thai-Myanmar Border (2003-2013): The Role of Parasite Genetic Factors. Clin Infect Dis, 63 (6), pp. 784-791. | Citations: 33 (Scopus) | Show Abstract | Read more

BACKGROUND: Deployment of mefloquine-artesunate (MAS3) on the Thailand-Myanmar border has led to a sustained reduction in falciparum malaria, although antimalarial efficacy has declined substantially in recent years. The role of Plasmodium falciparum K13 mutations (a marker of artemisinin resistance) in reducing treatment efficacy remains controversial. METHODS: Between 2003 and 2013, we studied the efficacy of MAS3 in 1005 patients with uncomplicated P. falciparum malaria in relation to molecular markers of resistance. RESULTS: Polymerase chain reaction (PCR)-adjusted cure rates declined from 100% in 2003 to 81.1% in 2013 as the proportions of isolates with multiple Pfmdr1 copies doubled from 32.4% to 64.7% and those with K13 mutations increased from 6.7% to 83.4%. K13 mutations conferring moderate artemisinin resistance (notably E252Q) predominated initially but were later overtaken by propeller mutations associated with slower parasite clearance (notably C580Y). Those infected with both multiple Pfmdr1 copy number and a K13 propeller mutation were 14 times more likely to fail treatment. The PCR-adjusted cure rate was 57.8% (95% confidence interval [CI], 45.4, 68.3) compared with 97.8% (95% CI, 93.3, 99.3) in patients with K13 wild type and Pfmdr1 single copy. K13 propeller mutation alone was a strong risk factor for recrudescence (P = .009). The combined population attributable fraction of recrudescence associated with K13 mutation and Pfmdr1 amplification was 82%. CONCLUSIONS: The increasing prevalence of K13 mutations was the decisive factor for the recent and rapid decline in efficacy of artemisinin-based combination (MAS3) on the Thailand-Myanmar border.

White NJ, Duong TT, Uthaisin C, Nosten F, Phyo AP, Hanboonkunupakarn B, Pukrittayakamee S, Jittamala P, Chuthasmit K, Cheung MS et al. 2016. Antimalarial Activity of KAF156 in Falciparum and Vivax Malaria. N Engl J Med, 375 (12), pp. 1152-1160. | Citations: 9 (Scopus) | Show Abstract | Read more

BACKGROUND: KAF156 belongs to a new class of antimalarial agents (imidazolopiperazines), with activity against asexual and sexual blood stages and the preerythrocytic liver stages of malarial parasites. METHODS: We conducted a phase 2, open-label, two-part study at five centers in Thailand and Vietnam to assess the antimalarial efficacy, safety, and pharmacokinetic profile of KAF156 in adults with acute Plasmodium vivax or P. falciparum malaria. Assessment of parasite clearance rates in cohorts of patients with vivax or falciparum malaria who were treated with multiple doses (400 mg once daily for 3 days) was followed by assessment of the cure rate at 28 days in a separate cohort of patients with falciparum malaria who received a single dose (800 mg). RESULTS: Median parasite clearance times were 45 hours (interquartile range, 42 to 48) in 10 patients with falciparum malaria and 24 hours (interquartile range, 20 to 30) in 10 patients with vivax malaria after treatment with the multiple-dose regimen and 49 hours (interquartile range, 42 to 54) in 21 patients with falciparum malaria after treatment with the single dose. Among the 21 patients who received the single dose and were followed for 28 days, 1 had reinfection and 7 had recrudescent infections (cure rate, 67%; 95% credible interval, 46 to 84). The mean (±SD) KAF156 terminal elimination half-life was 44.1±8.9 hours. There were no serious adverse events in this small study. The most common adverse events included sinus bradycardia, thrombocytopenia, hypokalemia, anemia, and hyperbilirubinemia. Vomiting of grade 2 or higher occurred in 2 patients, 1 of whom discontinued treatment because of repeated vomiting after receiving the single 800-mg dose. More adverse events were reported in the single-dose cohort, which had longer follow-up, than in the multiple-dose cohorts. CONCLUSIONS: KAF156 showed antimalarial activity without evident safety concerns in a small number of adults with uncomplicated P. vivax or P. falciparum malaria. (Funded by Novartis and others; number, NCT01753323 .).

Do NTT, Ta NTD, Tran NTH, Than HM, Vu BTN, Hoang LB, van Doorn HR, Vu DTV, Cals JWL, Chandna A et al. 2016. Point-of-care C-reactive protein testing to reduce inappropriate use of antibiotics for non-severe acute respiratory infections in Vietnamese primary health care: a randomised controlled trial. Lancet Glob Health, 4 (9), pp. e633-e641. | Citations: 12 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Inappropriate antibiotic use for acute respiratory tract infections is common in primary health care, but distinguishing serious from self-limiting infections is difficult, particularly in low-resource settings. We assessed whether C-reactive protein point-of-care testing can safely reduce antibiotic use in patients with non-severe acute respiratory tract infections in Vietnam. METHOD: We did a multicentre open-label randomised controlled trial in ten primary health-care centres in northern Vietnam. Patients aged 1-65 years with at least one focal and one systemic symptom of acute respiratory tract infection were assigned 1:1 to receive either C-reactive protein point-of-care testing or routine care, following which antibiotic prescribing decisions were made. Patients with severe acute respiratory tract infection were excluded. Enrolled patients were reassessed on day 3, 4, or 5, and on day 14 a structured telephone interview was done blind to the intervention. Randomised assignments were concealed from prescribers and patients but not masked as the test result was used to assist treatment decisions. The primary outcome was antibiotic use within 14 days of follow-up. All analyses were prespecified in the protocol and the statistical analysis plan. All analyses were done on the intention-to-treat population and the analysis of the primary endpoint was repeated in the per-protocol population. This trial is registered under number NCT01918579. FINDINGS: Between March 17, 2014, and July 3, 2015, 2037 patients (1028 children and 1009 adults) were enrolled and randomised. One adult patient withdrew immediately after randomisation. 1017 patients were assigned to receive C-reactive protein point-of-care testing, and 1019 patients were assigned to receive routine care. 115 patients in the C-reactive protein point-of-care group and 72 patients in the routine care group were excluded in the intention-to-treat analysis due to missing primary endpoint. The number of patients who used antibiotics within 14 days was 581 (64%) of 902 patients in the C-reactive protein group versus 738 (78%) of 947 patients in the control group (odds ratio [OR] 0·49, 95% CI 0·40-0·61; p<0·0001). Highly significant differences were seen in both children and adults, with substantial heterogeneity of the intervention effect across the 10 sites (I(2)=84%, 95% CI 66-96). 140 patients in the C-reactive protein group and 137 patients in the routine care group missed the urine test on day 3, 4, or 5. Antibiotic activity in urine on day 3, 4, or 5 was found in 267 (30%) of 877 patients in the C-reactive protein group versus 314 (36%) of 882 patients in the routine treatment group (OR 0·78, 95% CI 0·63-0·95; p=0·015). Time to resolution of symptoms was similar in both groups. Adverse events were rare, with no deaths and a total of 14 hospital admissions (six in the C-reactive protein group and eight in the control group). INTERPRETATION: C-reactive protein point-of-care testing reduced antibiotic use for non-severe acute respiratory tract infection without compromising patients' recovery in primary health care in Vietnam. Health-care providers might have become familiar with the clinical picture of low C-reactive protein, leading to reduction in antibiotic prescribing in both groups, but this would have led to a reduction in observed effect, rather than overestimation. Qualitative analysis is needed to address differences in context in order to implement this strategy to improve rational antibiotic use for patients with acute respiratory infection in low-income and middle-income countries. FUNDING: Wellcome Trust, UK, and Global Antibiotic Resistance Partnership, USA.

Levy Hara G, Kanj SS, Pagani L, Abbo L, Endimiani A, Wertheim HFL, Amábile-Cuevas C, Tattevin P, Mehtar S, Lopes Cardoso F et al. 2016. Ten key points for the appropriate use of antibiotics in hospitalised patients: a consensus from the Antimicrobial Stewardship and Resistance Working Groups of the International Society of Chemotherapy. Int J Antimicrob Agents, 48 (3), pp. 239-246. | Citations: 8 (Scopus) | Show Abstract | Read more

The Antibiotic Stewardship and Resistance Working Groups of the International Society for Chemotherapy propose ten key points for the appropriate use of antibiotics in hospital settings. (i) Get appropriate microbiological samples before antibiotic administration and carefully interpret the results: in the absence of clinical signs of infection, colonisation rarely requires antimicrobial treatment. (ii) Avoid the use of antibiotics to 'treat' fever: use them to treat infections, and investigate the root cause of fever prior to starting treatment. (iii) Start empirical antibiotic treatment after taking cultures, tailoring it to the site of infection, risk factors for multidrug-resistant bacteria, and the local microbiology and susceptibility patterns. (iv) Prescribe drugs at their optimal dosing and for an appropriate duration, adapted to each clinical situation and patient characteristics. (v) Use antibiotic combinations only where the current evidence suggests some benefit. (vi) When possible, avoid antibiotics with a higher likelihood of promoting drug resistance or hospital-acquired infections, or use them only as a last resort. (vii) Drain the infected foci quickly and remove all potentially or proven infected devices: control the infection source. (viii) Always try to de-escalate/streamline antibiotic treatment according to the clinical situation and the microbiological results. (ix) Stop unnecessarily prescribed antibiotics once the absence of infection is likely. And (x) Do not work alone: set up local teams with an infectious diseases specialist, clinical microbiologist, hospital pharmacist, infection control practitioner or hospital epidemiologist, and comply with hospital antibiotic policies and guidelines.

Delves MJ, Straschil U, Ruecker A, Miguel-Blanco C, Marques S, Dufour AC, Baum J, Sinden RE. 2016. Routine in vitro culture of P. falciparum gametocytes to evaluate novel transmission-blocking interventions. Nat Protoc, 11 (9), pp. 1668-1680. | Citations: 5 (Web of Science Lite) | Show Abstract | Read more

The prevention of parasite transmission from the human host to the mosquito has been recognized as a vital tool for malaria eradication campaigns. However, transmission-blocking antimalarial drug and/or vaccine discovery and development is currently hampered by the expense and difficulty of producing mature Plasmodium falciparum gametocytes in vitro-the parasite stage responsible for mosquito infection. Current protocols for P. falciparum gametocyte culture usually require complex parasite synchronization and addition of stimulating and/or inhibitory factors, and they may not have demonstrated the essential property of mosquito infectivity. This protocol details all the steps required for reliable P. falciparum gametocyte production and highlights common factors that influence culture success. The protocol can be completed in 15 d, and particular emphasis is placed upon operating a gametocyte culture facility on a continuous cycle. In addition, we show how functionally viable gametocytes can be used to evaluate transmission-blocking drugs both in a field setting and at high throughput (HTP) for drug discovery.

De Baetselier I, Mwambarangwe L, Cuylaerts V, Musengamana V, Agaba S, Kestelyn E, van de Wijgert J, Crucitti T. 2016. Evaluation of an enzymatic Chlamydia trachomatis point-of-care rapid assay in Rwanda: the BioChekSwab Rapid Test. Sex Transm Infect, 92 (6), pp. 430-432. | Citations: 2 (Scopus) | Show Abstract | Read more

OBJECTIVES: We evaluated the performance of an enzymatic point-of-care rapid test for Chlamydia trachomatis (CT) (the BioChekSwab CT Rapid Test, EnZtek Diagnostics, Rio Vista, California, USA), which detects CT's Peptidase 123CBV enzyme and provides a result 15 min after specimen collection. METHODS: Two endocervical swabs, including one BioChekSwab, per person were obtained from 137 women who participated in a reproductive health study in Rwanda. The BioChekSwab was processed according to the manufacturer's instructions. A substrate was squirted over the swab by the study physician immediately after collection, and another reagent was released over the swab tip at arrival in the laboratory. The test was considered positive if a blue colour developed within 2 min. The other regular flocked endocervical swab was processed at the Institute of Tropical Medicine (ITM), Belgium, using a testing algorithm: Abbott RealTime CT/Neisseria gonorrhoeae (NG) assay with the confirmation of positive results by an in-house real-time PCR assay. RESULTS: Of the 137 women, nine were CT positive by the testing algorithm. All nine positive results were missed by the BioChekSwab assay and four false-positive results were obtained. The sensitivity was therefore 0% (95% CI 0% to 33.6%) and the specificity was 96.9% (95% CI 92.2% to 99.1%). CONCLUSIONS: The BioChekSwab Rapid Test, although ISO13485 certified and Conformitée Européenne (CE) labelled, lacked any sensitivity in our setting.

Wolkewitz M, Cooper BS, Palomar-Martinez M, Alvarez-Lerma F, Olaechea-Astigarraga P, Barnett AG, Schumacher M. 2016. Multiple time scales in modeling the incidence of infections acquired in intensive care units. BMC Med Res Methodol, 16 (1), pp. 116. | Citations: 1 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: When patients are admitted to an intensive care unit (ICU) their risk of getting an infection will be highly depend on the length of stay at-risk in the ICU. In addition, risk of infection is likely to vary over calendar time as a result of fluctuations in the prevalence of the pathogen on the ward. Hence risk of infection is expected to depend on two time scales (time in ICU and calendar time) as well as competing events (discharge or death) and their spatial location. The purpose of this paper is to develop and apply appropriate statistical models for the risk of ICU-acquired infection accounting for multiple time scales, competing risks and the spatial clustering of the data. METHODS: A multi-center data base from a Spanish surveillance network was used to study the occurrence of an infection due to Methicillin-resistant Staphylococcus aureus (MRSA). The analysis included 84,843 patient admissions between January 2006 and December 2011 from 81 ICUs. Stratified Cox models were used to study multiple time scales while accounting for spatial clustering of the data (patients within ICUs) and for death or discharge as competing events for MRSA infection. RESULTS: Both time scales, time in ICU and calendar time, are highly associated with the MRSA hazard rate and cumulative risk. When using only one basic time scale, the interpretation and magnitude of several patient-individual risk factors differed. Risk factors concerning the severity of illness were more pronounced when using only calendar time. These differences disappeared when using both time scales simultaneously. CONCLUSIONS: The time-dependent dynamics of infections is complex and should be studied with models allowing for multiple time scales. For patient individual risk-factors we recommend stratified Cox regression models for competing events with ICU time as the basic time scale and calendar time as a covariate. The inclusion of calendar time and stratification by ICU allow to indirectly account for ICU-level effects such as local outbreaks or prevention interventions.

Falq G, Van Den Bergh R, De Smet M, Etienne W, Nguon C, Rekol H, Imwong M, Dondorp A, Kindermans J-M. 2016. Assessing the asymptomatic reservoir and dihydroartemisinin-piperaquine effectiveness in a low transmission setting threatened by artemisinin resistant Plasmodium falciparum. Malar J, 15 (1), pp. 446. | Citations: 2 (Scopus) | Show Abstract | Read more

BACKGROUND: In Cambodia, elimination of artemisinin resistance through direct elimination of the Plasmodium falciparum parasite may be the only strategy. Prevalence and incidence at district and village levels were assessed in Chey Saen district, Preah Vihear province, North of Cambodia. Molecular and clinical indicators for artemisinin resistance were documented. METHODS: A cross sectional prevalence survey was conducted at village level in the district of Chey Saen from September to October 2014. Plasmodium spp. was assessed with high volume quantitative real-time polymerase chain reaction (qPCR). Plasmodium falciparum-positive samples were screened for mutations in the k13-propeller domain gene. Treatment effectiveness was established after 28 days (D28) using the same qPCR technique. Data from the provincial surveillance system targeting symptomatic cases, supported by Médecins Sans Frontières (MSF), were used to assess incidence. RESULTS: District P. falciparum prevalence was of 0.74 % [0.41; 1.21]; village prevalence ranged from 0 to 4.6 % [1.4; 10.5]. The annual incidence of P. falciparum was 16.8 cases per 1000 inhabitants in the district; village incidence ranged from 1.3 to 54.9 for 1000 inhabitants. Two geographical clusters with high number of cases were identified by both approaches. The marker for artemisinin resistance was found in six samples out of the 11 tested (55 %). 34.9 % of qPCR blood analysis of symptomatic patients were still positive at D28. CONCLUSIONS: The overall low prevalence of P. falciparum was confirmed in Chey Saen district in Cambodia, while there were important variations between villages. Symptomatic cases had a different pattern and were likely acquired outside the villages. It illustrates the importance of prevalence surveys in targeting interventions for elimination. Mutations in the k13-propeller domain gene (C580Y), conferring artemisinin resistance, were highly prevalent in both symptomatic and asymptomatic cases (realizing the absolute figures remain low). Asymptomatic individuals could be an additional reservoir for artemisinin resistance. The low effectiveness of dihydroartemisinin-piperaquine (DHA-PPQ) for symptomatic cases indicates that PPQ is no longer able to complement the reduced potency of DHA to treat falciparum malaria and highlights the need for an alternative first-line treatment.

Donegani E, Paal P, Küpper T, Hefti U, Basnyat B, Carceller A, Bouzat P, van der Spek R, Hillebrandt D. 2016. Drug Use and Misuse in the Mountains: A UIAA MedCom Consensus Guide for Medical Professionals. High Alt Med Biol, 17 (3), pp. 157-184. | Citations: 3 (Web of Science Lite) | Show Abstract | Read more

Donegani, Enrico, Peter Paal, Thomas Küpper, Urs Hefti, Buddha Basnyat, Anna Carceller, Pierre Bouzat, Rianne van der Spek, and David Hillebrandt. Drug use and misuse in the mountains: a UIAA MedCom consensus guide for medical professionals. High Alt Med Biol. 17:157-184, 2016.-Aims: The aim of this review is to inform mountaineers about drugs commonly used in mountains. For many years, drugs have been used to enhance performance in mountaineering. It is the UIAA (International Climbing and Mountaineering Federation-Union International des Associations d'Alpinisme) Medcom's duty to protect mountaineers from possible harm caused by uninformed drug use. The UIAA Medcom assessed relevant articles in scientific literature and peer-reviewed studies, trials, observational studies, and case series to provide information for physicians on drugs commonly used in the mountain environment. Recommendations were graded according to criteria set by the American College of Chest Physicians. RESULTS: Prophylactic, therapeutic, and recreational uses of drugs relevant to mountaineering are presented with an assessment of their risks and benefits. CONCLUSIONS: If using drugs not regulated by the World Anti-Doping Agency (WADA), individuals have to determine their own personal standards for enjoyment, challenge, acceptable risk, and ethics. No system of drug testing could ever, or should ever, be policed for recreational climbers. Sponsored climbers or those who climb for status need to carefully consider both the medical and ethical implications if using drugs to aid performance. In some countries (e.g., Switzerland and Germany), administrative systems for mountaineering or medication control dictate a specific stance, but for most recreational mountaineers, any rules would be unenforceable and have to be a personal decision, but should take into account the current best evidence for risk, benefit, and sporting ethics.

Taylor AJ, Vongphayloth K, Vongsouvath M, Grandadam M, Brey PT, Newton PN, Sutherland IW, Dittrich S. 2016. Large-Scale Survey for Tickborne Bacteria, Khammouan Province, Laos. Emerg Infect Dis, 22 (9), pp. 1635-1639. | Show Abstract | Read more

We screened 768 tick pools containing 6,962 ticks from Khammouan Province, Laos, by using quantitative real-time PCR and identified Rickettsia spp., Ehrlichia spp., and Borrelia spp. Sequencing of Rickettsia spp.-positive and Borrelia spp.-positive pools provided evidence for distinct genotypes. Our results identified bacteria with human disease potential in ticks in Laos.

Arabi YM, Hajeer AH, Luke T, Raviprakash K, Balkhy H, Johani S, Al-Dawood A, Al-Qahtani S, Al-Omari A, Al-Hameed F et al. 2016. Feasibility of Using Convalescent Plasma Immunotherapy for MERS-CoV Infection, Saudi Arabia. Emerg Infect Dis, 22 (9), pp. 1554-1561. | Citations: 11 (Scopus) | Show Abstract | Read more

We explored the feasibility of collecting convalescent plasma for passive immunotherapy of Middle East respiratory syndrome coronavirus (MERS-CoV) infection by using ELISA to screen serum samples from 443 potential plasma donors: 196 patients with suspected or laboratory-confirmed MERS-CoV infection, 230 healthcare workers, and 17 household contacts exposed to MERS-CoV. ELISA-reactive samples were further tested by indirect fluorescent antibody and microneutralization assays. Of the 443 tested samples, 12 (2.7%) had a reactive ELISA result, and 9 of the 12 had reactive indirect fluorescent antibody and microneutralization assay titers. Undertaking clinical trials of convalescent plasma for passive immunotherapy of MERS-CoV infection may be feasible, but such trials would be challenging because of the small pool of potential donors with sufficiently high antibody titers. Alternative strategies to identify convalescent plasma donors with adequate antibody titers should be explored, including the sampling of serum from patients with more severe disease and sampling at earlier points during illness.

Whistler T, Kaewpan A, Blacksell SD. 2016. A Biological Safety Cabinet Certification Program: Experiences in Southeast Asia. Appl Biosaf, 21 (3), pp. 121-127. | Show Abstract | Read more

Biological safety cabinets (BSCs) are the primary means of containment used in laboratories worldwide for the safe handling of infectious microorganisms. They provide protection to the laboratory worker and the surrounding environment from pathogens. To ensure the correct functioning of BSCs, they need to be properly maintained beyond the daily care routines of the laboratory. This involves annual maintenance and certification by a qualified technician in accordance to the NSF/American National Standards Institute 49-2014 Biosafety Cabinetry: Design, Construction, Performance, and Field Certification. Service programs can be direct from the manufacturer or through third-party service companies, but in many instances, technicians are not accredited by international bodies, and these services are expensive. This means that a large number of BSCs may not be operating in a safe manner. In this article, we discuss our approach to addressing the lack of trained and qualified personnel in Thailand who can install, maintain, and certify BSCs in a cost-effective and practical manner. We initiated a program to create both local and regional capacity for repair, maintenance, and certification of BSCs and share our experiences with the reader.

Briand V, Le Hesran J-Y, Mayxay M, Newton PN, Bertin G, Houzé S, Keomany S, Inthavong Y, Vannavong N, Chindavongsa K et al. 2016. Prevalence of malaria in pregnancy in southern Laos: a cross-sectional survey. Malar J, 15 (1), pp. 436. | Citations: 3 (Scopus) | Show Abstract | Read more

BACKGROUND: There are no data on the burden of malaria in pregnancy (MiP) in Laos, where malaria still remains prevalent in the south. METHODS: Two cross-sectional surveys were conducted in 2014 to assess the prevalence of MiP in Vapi District, Salavan Province, southern Laos: the first consisted of screening 204 pregnant women during pregnancies [mean (95 % CI) gestational age: 23 (22-25) weeks] living in 30 randomly selected villages in Vapi District; the second was conducted among 331 pregnant women, who delivered during the study period in Vapi and Toumlane District Hospitals and in Salavan Provincial Hospital. Peripheral and placental malaria was detected using rapid diagnostic tests (RDT), thick blood smears (TBS) and real-time quantitative polymerase chain reactions (RT-qPCR). Factors associated with low birth weight (LBW) and maternal anaemia were assessed. RESULTS: In the villages, 12/204 women (5.9 %; 95 % CI 3.1-10.0) were infected with malaria as determined by RT-qPCR: 11 were Plasmodium vivax infections and 1 was mixed Plasmodium vivax/Plasmodium falciparum infection, among which 9 were sub-microscopic (as not detected by TBS). History of malaria during current pregnancy tended to be associated with a higher risk of MiP (aIRR 3.05; 95 % CI 0.94-9.88). At delivery, two Plasmodium falciparum sub-microscopic infections (one peripheral and one placental) were detected (4.5 %; 0.6-15.5) in Vapi District. In both surveys, all infected women stated they had slept under a bed net the night before the survey, and 86 % went to the forest for food-finding 1 week before the survey in median. The majority of infections (94 %) were asymptomatic and half of them were associated with anaemia. Overall, 24 % of women had LBW newborns. Factors associated with a higher risk of LBW were tobacco use (aIRR 2.43; 95 % CI 1.64-3.60) and pre-term delivery (aIRR 3.17; 95 % CI 2.19-4.57). Factors associated with a higher risk of maternal anaemia were no iron supplementation during pregnancy, Lao Theung ethnicity and place of living. CONCLUSIONS: The prevalence of MiP in this population was noticeable. Most infections were asymptomatic and sub-microscopic vivax malaria, which raises the question of reliability of recommended national strategies for the screening and prevention of MiP in Laos.

Chanthavilay P, Reinharz D, Mayxay M, Phongsavan K, Marsden DE, Moore L, White LJ. 2016. The economic evaluation of human papillomavirus vaccination strategies against cervical cancer in women in Lao PDR: a mathematical modelling approach. BMC Health Serv Res, 16 (1), pp. 418. | Show Abstract | Read more

BACKGROUND: Cervical cancer, a preventable disease, is the third leading cause of cancer morbidity and mortality in the Lao People's Democratic Republic (Lao PDR). Since many cervical cancers are linked to human papilloma virus (HPV) infection, vaccination against this virus may lead to a reduction in these types of cancer. The study described here is the first to compare the cost-effectiveness of different HPV vaccination options in Lao PDR. METHODS: A dynamic compartment model was created. The model included routine screening activities already in place, as well as theoretical interventions that included a 10-year old girl-only vaccination programme combined with/without a 10-year old boy vaccination programme and/or a catch-up component. The simulation was run over 100 years. In base case analyses, we assumed 70 % vaccination coverage with lifelong protection and 100 % efficacy against HPV types 16/18. The outcomes of interest were the incremental cost per Disability-Adjusted Life Year (DALY) averted. RESULTS: In base case analyses, according to the WHO definition of cost-effectiveness thresholds, vaccinating 10-year-old girls was very cost-effective. Adding a catch-up vaccination element for females aged 11-25 years was also very cost-effective, costing 1559 international dollars (I$) per DALY averted. Increasing the age limit of the catch-up vaccination component to 75 years old showed that this remained a cost-effective option (I$ 5840 per DALY averted). Adding a vaccination programme for 10-year-old boys was not found to be cost-effective unless a short time simulation (30 years or less) was considered, along with a catch-up vaccination component for both males and females. CONCLUSIONS: Adding a catch-up female vaccination component is more attractive than adding a 10-year-old boy vaccination component.

Salisbury P, Hall L, Kulkus S, Paw MK, Tun NW, Min AM, Chotivanich K, Srikanok S, Ontuwong P, Sirinonthachai S et al. 2016. Family planning knowledge, attitudes and practices in refugee and migrant pregnant and post-partum women on the Thailand-Myanmar border - a mixed methods study. Reprod Health, 13 (1), pp. 94. | Citations: 1 (Scopus) | Show Abstract | Read more

BACKGROUND: Lack of data in marginalized populations on knowledge, attitudes and practices (KAP) hampers efforts to improve modern contraceptive practice. A mixed methods study to better understand family planning KAP amongst refugee and migrant women on the Thailand-Myanmar border was conducted as part of an ongoing effort to improve reproductive health, particularly maternal mortality, through Shoklo Malaria Research Unit (SMRU) antenatal and birthing services. METHODS: Cross-sectional surveys and focus group discussions (FGDs) in currently pregnant women; and in-depth interviews (IDIs) in selected post-partum women with three children or more; were conducted. Quantitative data were described with medians and proportions and compared using standard statistical tests. Risk factors associated with high parity (>3) were identified using logistic regression analysis. Qualitative data were coded and grouped and discussed using identified themes. RESULTS: In January-March 2015, 978 women participated in cross-sectional studies, 120 in FGD and 21 in IDI. Major positive findings were: > 90 % of women knew about contraceptives for birth spacing, >60 % of women in the FGD and IDI reported use of family planning (FP) in the past and nearly all women knew where they could obtain FP supplies. Major gaps identified included: low uptake of long acting contraception (LAC), lack of awareness of emergency contraception (>90 % of women), unreliable estimates of when child bearing years end, and misconceptions surrounding female sterilization. Three was identified as the ideal number of children in the cross-sectional survey but less than half of the women with this parity or higher in the IDI actually adopted LAC leaving them at risk for unintended pregnancy. Discussing basic female anatomy using a simple diagram was well received in FGD and IDIs. LAC uptake has increased particularly the IUD from 2013-2015. CONCLUSION: Definitive contextual issues were identified during this study and a significant range of action points have been implemented in FP services at SMRU as a result, particularly in regard to the IUD. The importance of the role and attitudes of husbands were acknowledged by women and studies to investigate male perspectives in future may enhance FP practice in this area.

Stewardson AJ, Allignol A, Beyersmann J, Graves N, Schumacher M, Meyer R, Tacconelli E, De Angelis G, Farina C, Pezzoli F et al. 2016. The health and economic burden of bloodstream infections caused by antimicrobial-susceptible and non-susceptible Enterobacteriaceae and Staphylococcus aureus in European hospitals, 2010 and 2011: a multicentre retrospective cohort study Eurosurveillance, 21 (33), | Read more

Darton TC, Jones C, Blohmke CJ, Waddington CS, Zhou L, Peters A, Haworth K, Sie R, Green CA, Jeppesen CA et al. 2016. Using a Human Challenge Model of Infection to Measure Vaccine Efficacy: A Randomised, Controlled Trial Comparing the Typhoid Vaccines M01ZH09 with Placebo and Ty21a. PLoS Negl Trop Dis, 10 (8), pp. e0004926. | Citations: 10 (Scopus) | Show Abstract | Read more

BACKGROUND: Typhoid persists as a major cause of global morbidity. While several licensed vaccines to prevent typhoid are available, they are of only moderate efficacy and unsuitable for use in children less than two years of age. Development of new efficacious vaccines is complicated by the human host-restriction of Salmonella enterica serovar Typhi (S. Typhi) and lack of clear correlates of protection. In this study, we aimed to evaluate the protective efficacy of a single dose of the oral vaccine candidate, M01ZH09, in susceptible volunteers by direct typhoid challenge. METHODS AND FINDINGS: We performed a randomised, double-blind, placebo-controlled trial in healthy adult participants at a single centre in Oxford (UK). Participants were allocated to receive one dose of double-blinded M01ZH09 or placebo or 3-doses of open-label Ty21a. Twenty-eight days after vaccination, participants were challenged with 104CFU S. Typhi Quailes strain. The efficacy of M01ZH09 compared with placebo (primary outcome) was assessed as the percentage of participants reaching pre-defined endpoints constituting typhoid diagnosis (fever and/or bacteraemia) during the 14 days after challenge. Ninety-nine participants were randomised to receive M01ZH09 (n = 33), placebo (n = 33) or 3-doses of Ty21a (n = 33). After challenge, typhoid was diagnosed in 18/31 (58.1% [95% CI 39.1 to 75.5]) M01ZH09, 20/30 (66.7% [47.2 to 87.2]) placebo, and 13/30 (43.3% [25.5 to 62.6]) Ty21a vaccine recipients. Vaccine efficacy (VE) for one dose of M01ZH09 was 13% [95% CI -29 to 41] and 35% [-5 to 60] for 3-doses of Ty21a. Retrospective multivariable analyses demonstrated that pre-existing anti-Vi antibody significantly reduced susceptibility to infection after challenge; a 1 log increase in anti-Vi IgG resulting in a 71% decrease in the hazard ratio of typhoid diagnosis ([95% CI 30 to 88%], p = 0.006) during the 14 day challenge period. Limitations to the study included the requirement to limit the challenge period prior to treatment to 2 weeks, the intensity of the study procedures and the high challenge dose used resulting in a stringent model. CONCLUSIONS: Despite successfully demonstrating the use of a human challenge study to directly evaluate vaccine efficacy, a single-dose M01ZH09 failed to demonstrate significant protection after challenge with virulent Salmonella Typhi in this model. Anti-Vi antibody detected prior to vaccination played a major role in outcome after challenge. TRIAL REGISTRATION: (NCT01405521) and EudraCT (number 2011-000381-35).

Phu Huong Lan N, Le Thi Phuong T, Nguyen Huu H, Thuy L, Mather AE, Park SE, Marks F, Thwaites GE, Van Vinh Chau N, Thompson CN, Baker S. 2016. Invasive Non-typhoidal Salmonella Infections in Asia: Clinical Observations, Disease Outcome and Dominant Serovars from an Infectious Disease Hospital in Vietnam. PLoS Negl Trop Dis, 10 (8), pp. e0004857. | Citations: 4 (Scopus) | Show Abstract | Read more

Invasive non-typhoidal Salmonella (iNTS) infections are now a well-described cause of morbidity and mortality in children and HIV-infected adults in sub-Saharan Africa. In contrast, the epidemiology and clinical manifestations of iNTS disease in Asia are not well documented. We retrospectively identified >100 cases of iNTS infections in an infectious disease hospital in Southern Vietnam between 2008 and 2013. Clinical records were accessed to evaluate demographic and clinical factors associated with iNTS infection and to identify risk factors associated with death. Multi-locus sequence typing and antimicrobial susceptibility testing was performed on all organisms. Of 102 iNTS patients, 71% were HIV-infected, >90% were adults, 71% were male and 33% reported intravenous drug use. Twenty-six/92 (28%) patients with a known outcome died; HIV infection was significantly associated with death (p = 0.039). S. Enteritidis (Sequence Types (ST)11) (48%, 43/89) and S. Typhimurium (ST19, 34 and 1544) (26%, 23/89) were the most commonly identified serovars; S. Typhimurium was significantly more common in HIV-infected individuals (p = 0.003). Isolates from HIV-infected patients were more likely to exhibit reduced susceptibility against trimethoprim-sulfamethoxazole than HIV-negative patients (p = 0.037). We conclude that iNTS disease is a severe infection in Vietnam with a high mortality rate. As in sub-Saharan Africa, HIV infection was a risk factor for death, with the majority of the burden in this population found in HIV-infected adult men.

Zhang R, Lee W-C, Lau Y-L, Albrecht L, Lopes SCP, Costa FTM, Suwanarusk R, Nosten F, Cooke BM, Rénia L, Russell B. 2016. Rheopathologic Consequence of Plasmodium vivax Rosette Formation. PLoS Negl Trop Dis, 10 (8), pp. e0004912. | Citations: 3 (Scopus) | Show Abstract | Read more

Malaria parasites dramatically alter the rheological properties of infected red blood cells. In the case of Plasmodium vivax, the parasite rapidly decreases the shear elastic modulus of the invaded RBC, enabling it to avoid splenic clearance. This study highlights correlation between rosette formation and altered membrane deformability of P. vivax-infected erythrocytes, where the rosette-forming infected erythrocytes are significantly more rigid than their non-rosetting counterparts. The adhesion of normocytes to the PvIRBC is strong (mean binding force of 440pN) resulting in stable rosette formation even under high physiological shear flow stress. Rosetting may contribute to the sequestration of PvIRBC schizonts in the host microvasculature or spleen.

Cauchemez S, Nouvellet P, Cori A, Jombart T, Garske T, Clapham H, Moore S, Mills HL, Salje H, Collins C et al. 2016. Unraveling the drivers of MERS-CoV transmission. Proc Natl Acad Sci U S A, 113 (32), pp. 9081-9086. | Citations: 6 (Scopus) | Show Abstract | Read more

With more than 1,700 laboratory-confirmed infections, Middle East respiratory syndrome coronavirus (MERS-CoV) remains a significant threat for public health. However, the lack of detailed data on modes of transmission from the animal reservoir and between humans means that the drivers of MERS-CoV epidemics remain poorly characterized. Here, we develop a statistical framework to provide a comprehensive analysis of the transmission patterns underlying the 681 MERS-CoV cases detected in the Kingdom of Saudi Arabia (KSA) between January 2013 and July 2014. We assess how infections from the animal reservoir, the different levels of mixing, and heterogeneities in transmission have contributed to the buildup of MERS-CoV epidemics in KSA. We estimate that 12% [95% credible interval (CI): 9%, 15%] of cases were infected from the reservoir, the rest via human-to-human transmission in clusters (60%; CI: 57%, 63%), within (23%; CI: 20%, 27%), or between (5%; CI: 2%, 8%) regions. The reproduction number at the start of a cluster was 0.45 (CI: 0.33, 0.58) on average, but with large SD (0.53; CI: 0.35, 0.78). It was >1 in 12% (CI: 6%, 18%) of clusters but fell by approximately one-half (47% CI: 34%, 63%) its original value after 10 cases on average. The ongoing exposure of humans to MERS-CoV from the reservoir is of major concern, given the continued risk of substantial outbreaks in health care systems. The approach we present allows the study of infectious disease transmission when data linking cases to each other remain limited and uncertain.

Keyes LE, Mather L, Duke C, Regmi N, Phelan B, Pant S, Starling J, McElwee M, Cole D, McConnell T et al. 2016. Older age, chronic medical conditions and polypharmacy in Himalayan trekkers in Nepal: an epidemiologic survey and case series. J Travel Med, 23 (6), pp. taw052-taw052. | Citations: 1 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: The number of tourists in Nepal doubled between 2003 and 2013 is nearly 800 000. With the increased popularity of trekking, the number of those with pre-existing medical conditions requiring access to healthcare is likely to increase. We therefore sought to characterize the demographics and health status of trekkers on the Everest Base Camp route in the Solukhumbu Valley. In addition, we report cases that illustrate the potential complications of an ageing and medicated population of trekkers with underlying diseases. METHODS: Trekkers over 18 years were enrolled in a larger observational cohort study on blood pressure at high altitude at 2860 m. They answered a questionnaire regarding demographics, medical history and current medications. Acute medical problems relating to medication use that were brought to the attention of investigators were documented and are presented as case reports. RESULTS: We enrolled 670 trekkers, 394 (59%) male, with a mean age of 48 years (range 18-76). Pre-existing medical conditions were reported by 223 participants (33%). The most frequent conditions included hypertension, hypercholesterolemia, migraines and thyroid dysfunction. A total of 276 participants (41%) reported taking one or more medications. The most common medications were acetazolamide (79, 12%), antihypertensives (50, 8%) and NSAIDs (47, 7%), with 30 classes of drugs represented. Excluding acetazolamide, older trekkers (age >50 years) were more likely than younger ones to take medications (OR = 2.17; 95% CI 1.57-3.00; P <0.05). Acetazolamide use was not related to age. CONCLUSIONS: Our findings illustrate a wide variety of medical conditions present in trekkers in Nepal with wide-ranging potential complications that could pose difficulties in areas where medical care is scarce and evacuation difficult. Our cases illustrate the potential problems polypharmacy poses in trekkers, and the need for local and expedition healthcare workers to be aware of, and prepared for the common medical conditions present.

Muraya KW, Jones C, Berkley JA, Molyneux S. 2016. Perceptions of childhood undernutrition among rural households on the Kenyan coast - a qualitative study. BMC Public Health, 16 (1), pp. 693. | Show Abstract | Read more

BACKGROUND: Nutrition plays an important role in child survival and development. Treatment action in the management of child health and nutrition is influenced by perceptions of illness, and gender plays an important role. However, little is known about if and how moderate undernutrition is recognised among lay populations, or how local social norms and intra-household dynamics affect decisions to seek biomedical assistance for nutritional concerns. In this paper we describe how childhood nutritional problems are recognised and understood within rural households. We demonstrate how context influences local constructs of 'normal', and suggest the centrality of gender in the management of child health and nutrition in our research context. METHODS: This qualitative study was undertaken in Kilifi County on the Kenyan Coast. A set of 15 households whose children were engaged in a community-based nutrition intervention were followed up over a period of twelve months. Over a total of 54 household visits, group and individual in-depth interviews were conducted with a range of respondents, supplemented by non-participant observations. Eight in-depth interviews with community representatives were also conducted. RESULTS: Local taxonomies of childhood undernutrition were found to overlap with, but differ from, biomedical categories. In particular, moderate undernutrition was generally not recognised as a health problem requiring treatment action, but rather as routine and manageable, typically seasonal, weight-loss. Where symptoms were considered more serious and requiring remedial action, household management strategies were typically based on perceived aetiology of the illness. Additionally, gender emerged as a potentially central theme in childhood nutrition problems and related management. Women reported that they have primary responsibility for ensuring children's good health and nutritional status, and that they are often held accountable when their children are of sub-optimal health. CONCLUSION: Perceptions of child nutrition and illness and gendered roles within households influence treatment action, and engagement with nutrition interventions. Community-based nutrition interventions must recognise these complex realities.

Chung The H, Rabaa MA, Pham Thanh D, De Lappe N, Cormican M, Valcanis M, Howden BP, Wangchuk S, Bodhidatta L, Mason CJ et al. 2016. South Asia as a Reservoir for the Global Spread of Ciprofloxacin-Resistant Shigella sonnei: A Cross-Sectional Study. PLoS Med, 13 (8), pp. e1002055. | Citations: 5 (Scopus) | Show Abstract | Read more

BACKGROUND: Antimicrobial resistance is a major issue in the Shigellae, particularly as a specific multidrug-resistant (MDR) lineage of Shigella sonnei (lineage III) is becoming globally dominant. Ciprofloxacin is a recommended treatment for Shigella infections. However, ciprofloxacin-resistant S. sonnei are being increasingly isolated in Asia and sporadically reported on other continents. We hypothesized that Asia is a primary hub for the recent international spread of ciprofloxacin-resistant S. sonnei. METHODS AND FINDINGS: We performed whole-genome sequencing on a collection of 60 contemporaneous ciprofloxacin-resistant S. sonnei isolated in four countries within Asia (Vietnam, n = 11; Bhutan, n = 12; Thailand, n = 1; Cambodia, n = 1) and two outside of Asia (Australia, n = 19; Ireland, n = 16). We reconstructed the recent evolutionary history of these organisms and combined these data with their geographical location of isolation. Placing these sequences into a global phylogeny, we found that all ciprofloxacin-resistant S. sonnei formed a single clade within a Central Asian expansion of lineage III. Furthermore, our data show that resistance to ciprofloxacin within S. sonnei may be globally attributed to a single clonal emergence event, encompassing sequential gyrA-S83L, parC-S80I, and gyrA-D87G mutations. Geographical data predict that South Asia is the likely primary source of these organisms, which are being regularly exported across Asia and intercontinentally into Australia, the United States and Europe. Our analysis was limited by the number of S. sonnei sequences available from diverse geographical areas and time periods, and we cannot discount the potential existence of other unsampled reservoir populations of antimicrobial-resistant S. sonnei. CONCLUSIONS: This study suggests that a single clone, which is widespread in South Asia, is likely driving the current intercontinental surge of ciprofloxacin-resistant S. sonnei and is capable of establishing endemic transmission in new locations. Despite being limited in geographical scope, our work has major implications for understanding the international transfer of antimicrobial-resistant pathogens, with S. sonnei acting as a tractable model for studying how antimicrobial-resistant Gram-negative bacteria spread globally.

Lo Vecchio A, Dias JA, Berkley JA, Boey C, Cohen MB, Cruchet S, Liguoro I, Salazar Lindo E, Sandhu B, Sherman P et al. 2016. Comparison of Recommendations in Clinical Practice Guidelines for Acute Gastroenteritis in Children. J Pediatr Gastroenterol Nutr, 63 (2), pp. 226-235. | Citations: 1 (Web of Science Lite) | Show Abstract | Read more

OBJECTIVE: Acute gastroenteritis (AGE) is a major cause of child mortality and morbidity. This study aimed at systematically reviewing clinical practice guidelines (CPGs) on AGE to compare recommendations and provide the basis for developing single universal guidelines. METHODS: CPGs were identified by searching MEDLINE, Cochrane-Library, National Guideline Clearinghouse and Web sites of relevant societies/organizations producing and/or endorsing CPGs. RESULTS: The definition of AGE varies among the 15 CPGs identified. The parameters most frequently recommended to assess dehydration are skin turgor and sunken eyes (11/15, 73.3%), general appearance (11/15, 66.6%), capillary refill time, and mucous membranes appearance (9/15, 60%). Oral rehydration solution is universally recognized as first-line treatment. The majority of CPGs recommend hypo-osmolar (Na 45-60 mmol/L, 11/15, 66.6 %) or low-osmolality (Na 75 mmol/L, 9/15, 60%) solutions. In children who fail oral rehydration, most CPGs suggest intravenous rehydration (66.6%). However, nasogastric tube insertion for fluid administration is preferred according by 5/15 CPGs (33.3%). Changes in diet and withdrawal of food are discouraged by all CPGs, and early refeeding is strongly recommended in 13 of 15 (86.7%). Zinc is recommended as an adjunct to ORS by 10 of 15 (66.6%) CPGs, most of them from low-income countries. Probiotics are considered by 9 of 15 (60%) CPGs, 5 from high-income countries. Antiemetics are not recommended in 9 of 15 (60%) CPGs. Routine use of antibiotics is discouraged. CONCLUSIONS: Key recommendations for the management of AGE in children are similar in CPGs. Together with accurate review of evidence-base this may represent a starting point for developing universal recommendations for the management of children with AGE worldwide.

Afolabi MO, Tiono AB, Adetifa UJ, Yaro JB, Drammeh A, Nébié I, Bliss C, Hodgson SH, Anagnostou NA, Sanou GS et al. 2016. Safety and Immunogenicity of ChAd63 and MVA ME-TRAP in West African Children and Infants. Mol Ther, 24 (8), pp. 1470-1477. | Citations: 12 (Web of Science Lite) | Show Abstract | Read more

Malaria remains a significant global health burden and a vaccine would make a substantial contribution to malaria control. Chimpanzee Adenovirus 63 Modified Vaccinia Ankara Multiple epitope thrombospondin adhesion protein (ME-TRAP) and vaccination has shown significant efficacy against malaria sporozoite challenge in malaria-naive European volunteers and against malaria infection in Kenyan adults. Infants are the target age group for malaria vaccination; however, no studies have yet assessed T-cell responses in children and infants. We enrolled 138 Gambian and Burkinabe children in four different age-groups: 2-6 years old in The Gambia; 5-17 months old in Burkina Faso; 5-12 months old, and also 10 weeks old, in The Gambia; and evaluated the safety and immunogenicity of Chimpanzee Adenovirus 63 Modified Vaccinia Ankara ME-TRAP heterologous prime-boost immunization. The vaccines were well tolerated in all age groups with no vaccine-related serious adverse events. T-cell responses to vaccination peaked 7 days after boosting with Modified Vaccinia Ankara, with T-cell responses highest in 10 week-old infants. Heterologous prime-boost immunization with Chimpanzee Adenovirus 63 and Modified Vaccinia Ankara ME-TRAP was well tolerated in infants and children, inducing strong T-cell responses. We identify an approach that induces potent T-cell responses in infants, which may be useful for preventing other infectious diseases requiring cellular immunity.

Turner P, Pol S, Soeng S, Sar P, Neou L, Chea P, Day NP, Cooper BS, Turner C. 2016. High Prevalence of Antimicrobial-resistant Gram-negative Colonization in Hospitalized Cambodian Infants. Pediatr Infect Dis J, 35 (8), pp. 856-861. | Citations: 2 (Scopus) | Show Abstract | Read more

BACKGROUND: Antimicrobial-resistant Gram-negative infections are a significant cause of mortality in young infants. We aimed to determine characteristics of, and risk factors for, colonization and invasive infection caused by 3rd generation cephalosporin (3GC) or carbapenem-resistant organisms in outborn infants admitted to a neonatal unit (NU) in Cambodia. METHODS: During the first year of operation, patients admitted to the Angkor Hospital for Children NU, Siem Reap, Cambodia, underwent rectal swabbing on admission and twice weekly until discharge. Swabs were taken also from 7 environmental sites. Swabs were cultured to identify 3GC or carbapenem-resistant Acinetobacter sp., Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa. RESULTS: The study included 333 infants with a median age at NU admission of 10 days (range, 0-43). Colonization by ≥1 3GC-resistant organism was detected in 85.9% (286/333). Admission swabs were collected in 289 infants: 61.9% were colonized by a 3GC-resistant organism at the time of admission, and a further 23.2% were colonized during hospitalization, at a median of 4 days [95% confidence interval: 3-5]. Probiotic treatment (hazard ratio: 0.58; 95% confidence interval: 0.35-0.98) was associated with delayed colonization. Colonization by a carbapenem-resistant organism occurred in 25 (7.5%) infants. Six infants had NU-associated K. pneumoniae bacteremia; phenotypically identical colonizing strains were found in 3 infants. Environmental colonization occurred early. CONCLUSIONS: Colonization by antimicrobial-resistant Gram-negative organisms occurred early in hospitalized Cambodian infants and was associated with subsequent invasive infection. Trials of potential interventions such as probiotics are needed.

Boudhar A, Ng XW, Loh CY, Chia WN, Tan ZM, Nosten F, Dymock BW, Tan KSW. 2016. Overcoming chloroquine resistance in malaria: Design, synthesis and structure-activity relationships of novel chemoreversal agents. Eur J Med Chem, 119 pp. 231-249. | Citations: 5 (Web of Science Lite) | Show Abstract | Read more

Malaria remains a significant infectious disease with even artemisinin-based therapies now facing resistance in the field. Development of new therapies is urgently needed, either by finding new compounds with unique modes of action, or by reversing resistance towards known drugs with 'chemosensitizers' or 'chemoreversal' agents (CRA). Concerning the latter, we have focused on the resistance mechanisms developed against chloroquine (CQ). We have synthesized a series of compounds related to previously identified CRAs, and found promising novel compounds. These compounds show encouraging results in a coumarin labeled chloroquine uptake assay, exhibiting a dose response in resensitising parasites to the antimalarial effects of chloroquine. Selected compounds show consistent potency across a panel of chloroquine and artemisinin sensitive and resistant parasites, and a wide therapeutic window. This data supports further study of CRAs in the treatment of malaria and, ultimately, their use in chloroquine-based combination therapies.

Pham Thanh D, Thanh Tuyen H, Nguyen Thi Nguyen T, Chung The H, Wick RR, Thwaites GE, Baker S, Holt KE. 2016. Inducible colistin resistance via a disrupted plasmid-borne mcr-1 gene in a 2008 Vietnamese Shigella sonnei isolate. J Antimicrob Chemother, 71 (8), pp. 2314-2317. | Citations: 18 (Scopus) | Show Abstract | Read more

OBJECTIVES: The objective of this study was to assess the presence of mcr-1 in Shigella sonnei isolated in Vietnam. METHODS: WGS data were analysed for the presence of the mcr-1 gene sequence. The association of mcr-1 with a plasmid was assessed by PCR and by conjugation. RESULTS: Through genome sequencing we identified a plasmid-associated inactive form of mcr-1 in a 2008 Vietnamese isolate of Shigella sonnei. The plasmid was conjugated into Escherichia coli and mcr-1 was activated upon exposure to colistin, resulting in highly colistin-resistant transconjugants. CONCLUSIONS: This is the first description of the mcr-1 gene in Shigella, which is atypical given that colistin is not ordinarily used to treat diarrhoea. Our data suggest the mcr-1 gene has been circulating in human-restricted pathogens for some time but likely carries a selective fitness cost.

Gouliouris T, Blane B, Brodrick HJ, Raven KE, Ambridge KE, Kidney AD, Hadjirin NF, Török ME, Limmathurotsakul D, Peacock SJ. 2016. Comparison of two chromogenic media for the detection of vancomycin-resistant enterococcal carriage by nursing home residents. Diagn Microbiol Infect Dis, 85 (4), pp. 409-412. | Citations: 2 (Web of Science Lite) | Show Abstract | Read more

We compared ChromID VRE and Brilliance VRE media for the detection of vancomycin-resistant enterococci (VRE). Using a panel of 28 enterococcal isolates, 10 vanA Enterococcus faecium and three vanA Enterococcus faecalis isolates grew as per manufacturers' instructions whilst growth of two vanC and eight vancomycin-susceptible enterococci was inhibited on both media. Important differences were noted in the selectivity and chromogenic properties of the two media for vanA Enterococcus raffinosus and vanB E. faecium. The two media were further evaluated using 295 stool samples from nursing home residents, 34 of which grew VRE (11.5%). ChromID and Brilliance had comparable sensitivity, which was increased markedly by prolonging incubation to 48 hours (from 29% to 82%, and from 41% to 85%, respectively) and by a pre-enrichment step (to 97% and 100%, respectively). Brilliance VRE agar had higher selectivity at 48 hours, and after pre-enrichment.

Mijovic H, McKnight J, English M. 2016. What does the literature tell us about health workers' experiences of task-shifting projects in sub-Saharan Africa? A systematic, qualitative review. J Clin Nurs, 25 (15-16), pp. 2083-2100. | Citations: 2 (Web of Science Lite) | Show Abstract | Read more

AIMS AND OBJECTIVES: To review systematically, qualitative literature covering the implementation of task shifting in sub-Saharan Africa to address the growing interest in interventions of this kind. This review aims to distil the key practical findings to both guide a specific project aiming to improve the quality of neonatal care in Kenya and to contribute to the broader literature. BACKGROUND: Task-shifting programmes aim to improve access to healthcare by delegating specific tasks from higher to lower skilled health workers. Evidence suggests that task-shifting programmes in sub-Saharan Africa may improve patient outcomes, but they have also been criticised for providing fragmented, unsustainable services. This systematic review of qualitative literature summarises factors affecting implementation of task shifting and how such interventions in sub-Saharan Africa may have affected health workers' feelings about their own positions and their ability to provide care. DESIGN: Following literature search, a modified Critical Appraisal Skills Program (CASP) framework was used to assess quality. Thereafter, analysis adopted a thematic synthesis approach. METHODS: A systematic literature search identified qualitative studies examining task -shifting interventions in sub-Saharan Africa. Thematic synthesis was used to identify overarching themes arising from across the studies and infer how task-shifting interventions may impact on the health workers from whom tasks are being shifted. RESULTS: From the 230 studies screened, 13 met the inclusion criteria. Overarching themes identified showed that task shifting has been associated with jurisdictional debates linked to new cadres working beyond their scope of practice, and tension around compensation and career development for those taking on tasks that were being delegated. CONCLUSIONS: Based on the qualitative data available, it appears that task shifting may negatively impact the sense of agency and the ability to perform of health workers' from whom tasks are shifted. The potential implications of task shifting on all health workers should be considered prior to implementing task-shifting solutions.

Stettler K, Beltramello M, Espinosa DA, Graham V, Cassotta A, Bianchi S, Vanzetta F, Minola A, Jaconi S, Mele F et al. 2016. Specificity, cross-reactivity, and function of antibodies elicited by Zika virus infection. Science, 353 (6301), pp. 823-826. | Citations: 120 (Web of Science Lite) | Show Abstract | Read more

Zika virus (ZIKV), a mosquito-borne flavivirus with homology to Dengue virus (DENV), has become a public health emergency. By characterizing memory lymphocytes from ZIKV-infected patients, we dissected ZIKV-specific and DENV-cross-reactive immune responses. Antibodies to nonstructural protein 1 (NS1) were largely ZIKV-specific and were used to develop a serological diagnostic tool. In contrast, antibodies against E protein domain I/II (EDI/II) were cross-reactive and, although poorly neutralizing, potently enhanced ZIKV and DENV infection in vitro and lethally enhanced DENV disease in mice. Memory T cells against NS1 or E proteins were poorly cross-reactive, even in donors preexposed to DENV. The most potent neutralizing antibodies were ZIKV-specific and targeted EDIII or quaternary epitopes on infectious virus. An EDIII-specific antibody protected mice from lethal ZIKV infection, illustrating the potential for antibody-based therapy.

Boullé M, Witkowski B, Duru V, Sriprawat K, Nair SK, McDew-White M, Anderson TJC, Phyo AP, Menard D, Nosten F. 2016. Artemisinin-Resistant Plasmodium falciparum K13 Mutant Alleles, Thailand-Myanmar Border. Emerg Infect Dis, 22 (8), pp. 1503-1505. | Citations: 3 (Web of Science Lite) | Read more

Dittrich S, Card E, Phuklia W, Rudgard WE, Silousok J, Phoumin P, Bouthasavong L, Azarian S, Davong V, Dance DAB et al. 2016. Survival and Growth of Orientia tsutsugamushi in Conventional Hemocultures. Emerg Infect Dis, 22 (8), pp. 1460-1463. | Show Abstract | Read more

Orientia tsutsugamushi, which requires specialized facilities for culture, is a substantial cause of disease in Asia. We demonstrate that O. tsutsugamushi numbers increased for up to 5 days in conventional hemocultures. Performing such a culture step before molecular testing could increase the sensitivity of O. tsutsugamushi molecular diagnosis.

Recker M, Vannice K, Hombach J, Jit M, Simmons CP. 2016. Assessing dengue vaccination impact: Model challenges and future directions. Vaccine, 34 (38), pp. 4461-4465. | Citations: 3 (Web of Science Lite) | Show Abstract | Read more

In response to the sharp rise in the global burden caused by dengue virus (DENV) over the last few decades, the WHO has set out three specific key objectives in its disease control strategy: (i) to estimate the true burden of dengue by 2015; (ii) a reduction in dengue mortality by at least 50% by 2020 (used as a baseline); and (iii) a reduction in dengue morbidity by at least 25% by 2020. Although various elements will all play crucial parts in achieving this goal, from diagnosis and case management to integrated surveillance and outbreak response, sustainable vector control, vaccine implementation and finally operational and implementation research, it seems clear that new tools (e.g. a safe and effective vaccine and/or effective vector control) are key to success. The first dengue vaccine was licensed in December 2015, Dengvaxia® (CYD-TDV) developed by Sanofi Pasteur. The WHO has provided guidance on the use of CYD-TDV in endemic countries, for which there are a variety of considerations beyond the risk-benefit evaluation done by regulatory authorities, including public health impact and cost-effectiveness. Population-level vaccine impact and economic and financial aspects are two issues that can potentially be considered by means of mathematical modelling, especially for new products for which empirical data are still lacking. In December 2014 a meeting was convened by the WHO in order to revisit the current status of dengue transmission models and their utility for public health decision-making. Here, we report on the main points of discussion and the conclusions of this meeting, as well as next steps for maximising the use of mathematical models for vaccine decision-making.

Churchill D, Waters L, Ahmed N, Angus B, Boffito M, Bower M, Dunn D, Edwards S, Emerson C, Fidler S et al. 2016. British HIV Association guidelines for the treatment of HIV-1-positive adults with antiretroviral therapy 2015. HIV Med, 17 Suppl 4 pp. s2-s104. | Citations: 18 (Scopus) | Read more

Font-Gonzalez A, Feijen EL, Sieswerda E, van Dulmen-den Broeder E, Grootenhuis M, Maurice-Stam H, Caron H, Essink-Bot M-L, van der Pal H, Geskus R, Kremer L. 2016. Social outcomes in adult survivors of childhood cancer compared to the general population: linkage of a cohort with population registers. Psychooncology, 25 (8), pp. 933-941. | Citations: 3 (Scopus) | Show Abstract | Read more

OBJECTIVE: Self-reported data show differences in social outcomes (not being married/having a registered partnership; not living independently; using social benefits) for childhood cancer survivors compared with their peers. We aimed to determine differences in these social outcomes between survivors and the general population using national register data and explored associated risk factors. METHODS: We performed medical record linkage between a single-centre cohort of 1768 ≥ 5-year survivors of childhood cancer (diagnosed 1966-2001) and two national registers (1999-2011) and obtained a random reference sample matched on gender and year of birth per survivor. We used multivariable logistic regression to calculate in adult survivors of childhood cancer (born before 1990) the odds of the specified social outcomes at the end of follow-up in both groups. Within the survivors, we analysed risk factors for the social outcomes. RESULTS: We retrieved data from 1283 adult childhood cancer survivors and 25 082 reference persons. Survivors had higher odds (odds ratio; 95% confidence interval) of not being married (1.2; 1.07-1.42), not living independently (1.7; 1.41-2.00) and using social benefits (2.3; 1.98-2.69) compared with reference persons. Radiotherapy to head and/or neck, and an original central nervous system tumour diagnosis negatively influenced all social outcomes examined in childhood cancer survivors. CONCLUSIONS: National register data show differences between social outcomes in childhood cancer survivors and the general population, especially for survivors treated with radiotherapy to head and/or neck and those originally diagnosed with central nervous system tumours. Development and implementation of effective targeted support strategies to improve social outcomes of childhood cancer survivors needs consideration. Copyright © 2015 John Wiley & Sons, Ltd.

Robinson TP, Bu DP, Carrique-Mas J, Fèvre EM, Gilbert M, Grace D, Hay SI, Jiwakanon J, Kakkar M, Kariuki S et al. 2016. Antibiotic resistance is the quintessential One Health issue. Trans R Soc Trop Med Hyg, 110 (7), pp. 377-380. | Citations: 18 (Web of Science Lite) | Read more

Suntornsut P, Wongsuwan N, Malasit M, Kitphati R, Michie S, Peacock SJ, Limmathurotsakul D. 2016. Barriers and Recommended Interventions to Prevent Melioidosis in Northeast Thailand: A Focus Group Study Using the Behaviour Change Wheel. PLoS Negl Trop Dis, 10 (7), pp. e0004823. | Citations: 2 (Scopus) | Show Abstract | Read more

BACKGROUND: Melioidosis, an often fatal infectious disease in Northeast Thailand, is caused by skin inoculation, inhalation or ingestion of the environmental bacterium, Burkholderia pseudomallei. The major underlying risk factor for melioidosis is diabetes mellitus. Recommendations for melioidosis prevention include using protective gear such as rubber boots and gloves when in direct contact with soil and environmental water, and consuming bottled or boiled water. Only a small proportion of people follow such recommendations. METHODS: Nine focus group discussions were conducted to evaluate barriers to adopting recommended preventive behaviours. A total of 76 diabetic patients from northeast Thailand participated in focus group sessions. Barriers to adopting the recommended preventive behaviours and future intervention strategies were identified using two frameworks: the Theoretical Domains Framework and the Behaviour Change Wheel. RESULTS: Barriers were identified in the following five domains: (i) knowledge, (ii) beliefs about consequences, (iii) intention and goals, (iv) environmental context and resources, and (v) social influence. Of 76 participants, 72 (95%) had never heard of melioidosis. Most participants saw no harm in not adopting recommended preventive behaviours, and perceived rubber boots and gloves to be hot and uncomfortable while working in muddy rice fields. Participants reported that they normally followed the behaviour of friends, family and their community, the majority of whom did not wear boots while working in rice fields and did not boil water before drinking. Eight intervention functions were identified as relevant for the intervention: (i) education, (ii) persuasion, (iii) incentivisation, (iv) coercion, (v) modeling, (vi) environmental restructuring, (vii) training, and (viii) enablement. Participants noted that input from role models in the form of physicians, diabetic clinics, friends and families, and from the government via mass media would be required for them to change their behaviours. CONCLUSION: There are numerous barriers to the adoption of behaviours recommended for melioidosis prevention. We recommend that a multifaceted intervention at community and government level is required to achieve the desired behaviour changes.

Van Voorhis WC, Adams JH, Adelfio R, Ahyong V, Akabas MH, Alano P, Alday A, Alemán Resto Y, Alsibaee A, Alzualde A et al. 2016. Open Source Drug Discovery with the Malaria Box Compound Collection for Neglected Diseases and Beyond. PLoS Pathog, 12 (7), pp. e1005763. | Citations: 29 (Scopus) | Show Abstract | Read more

A major cause of the paucity of new starting points for drug discovery is the lack of interaction between academia and industry. Much of the global resource in biology is present in universities, whereas the focus of medicinal chemistry is still largely within industry. Open source drug discovery, with sharing of information, is clearly a first step towards overcoming this gap. But the interface could especially be bridged through a scale-up of open sharing of physical compounds, which would accelerate the finding of new starting points for drug discovery. The Medicines for Malaria Venture Malaria Box is a collection of over 400 compounds representing families of structures identified in phenotypic screens of pharmaceutical and academic libraries against the Plasmodium falciparum malaria parasite. The set has now been distributed to almost 200 research groups globally in the last two years, with the only stipulation that information from the screens is deposited in the public domain. This paper reports for the first time on 236 screens that have been carried out against the Malaria Box and compares these results with 55 assays that were previously published, in a format that allows a meta-analysis of the combined dataset. The combined biochemical and cellular assays presented here suggest mechanisms of action for 135 (34%) of the compounds active in killing multiple life-cycle stages of the malaria parasite, including asexual blood, liver, gametocyte, gametes and insect ookinete stages. In addition, many compounds demonstrated activity against other pathogens, showing hits in assays with 16 protozoa, 7 helminths, 9 bacterial and mycobacterial species, the dengue fever mosquito vector, and the NCI60 human cancer cell line panel of 60 human tumor cell lines. Toxicological, pharmacokinetic and metabolic properties were collected on all the compounds, assisting in the selection of the most promising candidates for murine proof-of-concept experiments and medicinal chemistry programs. The data for all of these assays are presented and analyzed to show how outstanding leads for many indications can be selected. These results reveal the immense potential for translating the dispersed expertise in biological assays involving human pathogens into drug discovery starting points, by providing open access to new families of molecules, and emphasize how a small additional investment made to help acquire and distribute compounds, and sharing the data, can catalyze drug discovery for dozens of different indications. Another lesson is that when multiple screens from different groups are run on the same library, results can be integrated quickly to select the most valuable starting points for subsequent medicinal chemistry efforts.

Kinyoki DK, Berkley JA, Moloney GM, Odundo EO, Kandala N-B, Noor AM. 2016. Environmental predictors of stunting among children under-five in Somalia: cross-sectional studies from 2007 to 2010. BMC Public Health, 16 (1), pp. 654. | Show Abstract | Read more

BACKGROUND: Stunting among children under five years old is associated with long-term effects on cognitive development, school achievement, economic productivity in adulthood and maternal reproductive outcomes. Accurate estimation of stunting and tools to forecast risk are key to planning interventions. We estimated the prevalence and distribution of stunting among children under five years in Somalia from 2007 to 2010 and explored the role of environmental covariates in its forecasting. METHODS: Data from household nutritional surveys in Somalia from 2007 to 2010 with a total of 1,066 clusters covering 73,778 children were included. We developed a Bayesian hierarchical space-time model to forecast stunting by using the relationship between observed stunting and environmental covariates in the preceding years. We then applied the model coefficients to environmental covariates in subsequent years. To determine the accuracy of the forecasting, we compared this model with a model that used data from all the years with the corresponding environmental covariates. RESULTS: Rainfall (OR = 0.994, 95 % Credible interval (CrI): 0.993, 0.995) and vegetation cover (OR = 0.719, 95 % CrI: 0.603, 0.858) were significant in forecasting stunting. The difference in estimates of stunting using the two approaches was less than 3 % in all the regions for all forecast years. CONCLUSION: Stunting in Somalia is spatially and temporally heterogeneous. Rainfall and vegetation are major drivers of these variations. The use of environmental covariates for forecasting of stunting is a potentially useful and affordable tool for planning interventions to reduce the high burden of malnutrition in Somalia.

Nguyen DNT, Mai LQ, Bryant JE, Hang NLK, Hoa LNM, Nadjm B, Thai PQ, Duong TN, Anh DD, Horby P et al. 2016. Epidemiology and etiology of influenza-like-illness in households in Vietnam; it's not all about the kids! J Clin Virol, 82 pp. 126-132. | Citations: 3 (Scopus) | Show Abstract | Read more

BACKGROUND: Household studies provide opportunities to understand influenza-like-illness (ILI) transmission, but data from (sub)tropical developing countries are scarce. OBJECTIVE: To determine the viral etiology and epidemiology of ILI in households. STUDY DESIGN: ILI was detected by active case finding amongst a cohort of 263 northern Vietnam households between 2008 and 2013. Health workers collected nose and throat swabs for virus detection by multiplex real-time RT-PCR. RESULTS: ILI was detected at least once in 219 (23.7%) of 945 household members. 271 (62.3%) of 435 nose/throat swabs were positive for at least one of the 15 viruses tested. Six viruses predominated amongst positive swabs: Rhinovirus (28%), Influenza virus (17%), Coronavirus (8%), Enterovirus (5%), Respiratory syncytial virus (3%), Metapneumovirus virus (2.5%) and Parainfluenza virus 3 (1.8%). There was no clear seasonality, but 78% of episodes occurred in Winter/Spring for Influenza compared to 32% for Rhinovirus. Participants, on average, suffered 0.49 ILI, and 0.29 virus-positive ILI episodes, with no significant effects of gender, age, or household size. In contrast to US and Australian community studies, the frequency of ILI decreased as the number of household members aged below 5 years increased (p=0.006). CONCLUSION: The findings indicate the need for tailored ILI control strategies, and for better understanding of how local childcare practices and seasonality may influence transmission and the role of children.

Briend A, Berkley JA. 2016. Long term health status of children recovering from severe acute malnutrition. Lancet Glob Health, 4 (9), pp. e590-e591. | Citations: 1 (Scopus) | Read more

Hien HTA, Thanh TT, Thu NTM, Nguyen A, Thanh NT, Lan NPH, Simmons C, Shikuma C, Chau NVV, Thwaites G, Le T. 2016. Development and evaluation of a real-time polymerase chain reaction assay for the rapid detection of Talaromyces marneffei MP1 gene in human plasma. Mycoses, 59 (12), pp. 773-780. | Citations: 2 (Scopus) | Show Abstract | Read more

Penicilliosis caused by Talaromyces marneffei is a common AIDS-defining illness in South and Southeast Asia. Diagnosis is based on culture which can take up to 14 days for identification, leading to treatment delay and increased mortality. We developed a TaqMan real-time PCR assay targeting the MP1 gene encoding an abundant cell wall protein specific to T. marneffei. The assay's performance was evaluated in MP1-containing plasmids, clinical isolates, and plasma from HIV-infected patients with and without penicilliosis. The assay consistently detected 10 copies of MP1-containing plasmids per reaction and 100 T. marneffei yeast cells per millilitre plasma. There were no amplification with seven other Penicillium species and six other HIV-associated fungal pathogens tested. The assay was evaluated in 70 patients with AIDS: 50 patients with culture-confirmed penicilliosis and 20 patients with opportunistic infections other than penicilliosis. The diagnostic sensitivity was 70.4% (19/27, 95% CI: 51.5-84.1%) and 52.2% (12/23, 95% CI: 33.0-70.8%) in plasma samples collected prior to and within 48 h of antifungal therapy respectively. The diagnostic specificity was 100% (20/20, 95% CI: 83.9-100%). This assay provides a useful tool for the rapid diagnosis of T. marneffei infection and has the potential to improve the management of patients with penicilliosis.

Gimode D, Odeny DA, de Villiers EP, Wanyonyi S, Dida MM, Mneney EE, Muchugi A, Machuka J, de Villiers SM. 2016. Identification of SNP and SSR Markers in Finger Millet Using Next Generation Sequencing Technologies PLOS ONE, 11 (7), pp. e0159437-e0159437. | Read more

Auburn S, Serre D, Pearson RD, Amato R, Sriprawat K, To S, Handayuni I, Suwanarusk R, Russell B, Drury E et al. 2016. Genomic Analysis Reveals a Common Breakpoint in Amplifications of the Plasmodium vivax Multidrug Resistance 1 Locus in Thailand. J Infect Dis, 214 (8), pp. 1235-1242. | Citations: 5 (Web of Science Lite) | Show Abstract | Read more

In regions of coendemicity for Plasmodium falciparum and Plasmodium vivax where mefloquine is used to treat P. falciparum infection, drug pressure mediated by increased copy numbers of the multidrug resistance 1 gene (pvmdr1) may select for mefloquine-resistant P. vivax Surveillance is not undertaken routinely owing in part to methodological challenges in detection of gene amplification. Using genomic data on 88 P. vivax samples from western Thailand, we identified pvmdr1 amplification in 17 isolates, all exhibiting tandem copies of a 37.6-kilobase pair region with identical breakpoints. A novel breakpoint-specific polymerase chain reaction assay was designed to detect the amplification. The assay demonstrated high sensitivity, identifying amplifications in 13 additional, polyclonal infections. Application to 132 further samples identified the common breakpoint in all years tested (2003-2015), with a decline in prevalence after 2012 corresponding to local discontinuation of mefloquine regimens. Assessment of the structure of pvmdr1 amplification in other geographic regions will yield information about the population-specificity of the breakpoints and underlying amplification mechanisms.

Moore CE, Giess A, Soeng S, Sar P, Kumar V, Nhoung P, Bousfield R, Turner P, Stoesser N, Day NPJ, Parry CM. 2016. Characterisation of Invasive Streptococcus pneumoniae Isolated from Cambodian Children between 2007 - 2012. PLoS One, 11 (7), pp. e0159358. | Citations: 4 (Scopus) | Show Abstract | Read more

BACKGROUND: The 13-valent pneumococcal vaccine (PCV13) was introduced in Cambodia in January 2015. There are limited data concerning the common serotypes causing invasive pneumococcal disease (IPD). Knowledge of the circulating pneumococcal serotypes is important to monitor epidemiological changes before and after vaccine implementation. METHODS: All episodes of IPD defined by the isolation of Streptococcus pneumoniae from blood, cerebrospinal fluid or other sterile site in Cambodian children admitted to the Angkor Hospital for Children in Siem Reap, Northwestern Cambodia, between 1st January 2007 and 1st July 2012 were retrospectively studied. Streptococcus pneumoniae isolates that could be retrieved underwent phenotypic typing and whole genome sequencing. RESULTS: There were 90 Cambodian children hospitalized with IPD with a median (IQR) age of 2.3 years (0.9-6.2). The case fatality was 15.6% (95% CI 8-23). Of 50 Streptococcus pneumoniae isolates available for further testing, 46% were penicillin non-susceptible and 8% were ceftriaxone non-susceptible, 78% were cotrimoxazole resistant, 30% were erythromycin resistant and 30% chloramphenicol resistant. There were no significant changes in resistance levels over the five-year period. The most common serotypes were 1 (11/50; 22%), 23F (8/50; 16%), 14 (6/50; 12%), 5 (5/50; 10%) and 19A (3/50; 6%). Coverage by PCV7, PCV10 and PCV13 was 44%, 76% and 92% respectively. We identified novel multilocus sequence types and resistotypes using whole genome sequencing. CONCLUSIONS: This study suggests IPD is an important disease in Cambodian children and can have a significant mortality. PCV13 coverage of the serotypes determined in studied strains was high and consistent with another recent study. The phenotypic resistance patterns observed were similar to other regional studies. The use of whole genome sequencing in the present study provides additional typing and resistance information together with the description of novel sequence types and resistotypes.

Sieswerda E, Font-Gonzalez A, Reitsma JB, Dijkgraaf MGW, Heinen RC, Jaspers MW, van der Pal HJ, van Leeuwen FE, Caron HN, Geskus RB, Kremer LC. 2016. High Hospitalization Rates in Survivors of Childhood Cancer: A Longitudinal Follow-Up Study Using Medical Record Linkage. PLoS One, 11 (7), pp. e0159518. | Citations: 4 (Scopus) | Show Abstract | Read more

Hospitalization rates over time of childhood cancer survivors (CCS) provide insight into the burden of unfavorable health conditions on CCS and health care resources. The objective of our study was to examine trends in hospitalizations of CCS and risk factors in comparison with the general population. We performed a medical record linkage study of a cohort of 1564 ≥five-year CCS with national registers. We obtained a random sample of the general population matched on year of birth, gender and calendar year per CCS retrieved. We quantified and compared hospitalization rates of CCS and reference persons from 1995 until 2005, and we analyzed risk factors for hospitalization within the CCS cohort with multivariable Poisson models. We retrieved hospitalization information from 1382 CCS and 25583 reference persons. The overall relative hospitalization rate (RHR) was 2.2 (95%CI:1.9-2.5) for CCS compared to reference persons. CCS with central nervous system and solid tumors had highest RHRs. Hospitalization rates in CCS were increased compared to reference persons up to at least 30 years after primary diagnosis, with highest rates 5-10 and 20-30 years after primary cancer. RHRs were highest for hospitalizations due to neoplasms (10.7; 95%CI:7.1-16.3) and endocrine/nutritional/metabolic disorders (7.3; 95%CI:4.6-11.7). Female gender (P<0.001), radiotherapy to head and/or neck (P<0.001) or thorax and/or abdomen (P = 0.03) and surgery (P = 0.01) were associated with higher hospitalization rates in CCS. In conclusion, CCS have increased hospitalization rates compared to the general population, up to at least 30 years after primary cancer treatment. These findings imply a high and long-term burden of unfavorable health conditions after childhood cancer on survivors and health care resources.

Douangngeun B, Theppangna W, Soukvilay V, Senaphanh C, Phithacthep K, Phomhaksa S, Yingst S, Lombardini E, Hansson E, Selleck PW, Blacksell SD. 2016. Seroprevalence of Q Fever, Brucellosis, and Bluetongue in Selected Provinces in Lao People's Democratic Republic. Am J Trop Med Hyg, 95 (3), pp. 558-561. | Citations: 3 (Web of Science Lite) | Show Abstract | Read more

This study has determined the proportional seropositivity of two zoonotic diseases, Q fever and brucellosis, and bluetongue virus (BTV) which is nonzoonotic, in five provinces of Lao People's Democratic Republic (PDR) (Loungphabang, Luangnumtha, Xayaboury, Xiengkhouang, and Champasak, and Vientiane Province and Vientiane capital). A total of 1,089 samples from buffalo, cattle, pigs, and goats were tested, with seropositivity of BTV (96.7%), Q fever (1.2%), and brucellosis (0.3%). The results of this survey indicated that Q fever seropositivity is not widely distributed in Lao PDR; however, Xayaboury Province had a cluster of seropositive cattle in seven villages in four districts (Botan, Kenthao, Paklaiy, and Phiang) that share a border with Thailand. Further studies are required to determine if Xayaboury Province is indeed an epidemiological hot spot of Q fever activity. There is an urgent need to determine the levels of economic loss and human health-related issues caused by Q fever, brucellosis, and BTV in Lao PDR.

Bassat Q, Velarde M, Mueller I, Lin J, Leslie T, Wongsrichanalai C, Baird JK. 2016. Key Knowledge Gaps for Plasmodium vivax Control and Elimination. Am J Trop Med Hyg, 95 (6 Suppl), pp. 62-71. | Citations: 7 (Scopus) | Show Abstract | Read more

There is inadequate understanding of the biology, pathology, transmission, and control of Plasmodium vivax, the geographically most widespread cause of human malaria. During the last decades, study of this species was neglected, in part due to the erroneous belief that it is intrinsically benign. In addition, many technical challenges in culturing the parasite also hampered understanding its fundamental biology and molecular and cellular responses to chemotherapeutics. Research on vivax malaria needs to be substantially expanded over the next decade to accelerate its elimination and eradication. This article summarizes key knowledge gaps identified by researchers, national malaria control programs, and other stakeholders assembled by the World Health Organization to develop strategies for controlling and eliminating vivax malaria. The priorities presented in this article emerged in these technical discussions, and were adopted by expert consensus of the authors. All involved understood the priority placed upon pragmatism in this research agenda, that is, focus upon tools delivering better prevention, diagnosis, treatment, and surveillance of P. vivax.

Kohler C, Dunachie SJ, Müller E, Kohler A, Jenjaroen K, Teparrukkul P, Baier V, Ehricht R, Steinmetz I. 2016. Rapid and Sensitive Multiplex Detection of Burkholderia pseudomallei-Specific Antibodies in Melioidosis Patients Based on a Protein Microarray Approach. PLoS Negl Trop Dis, 10 (7), pp. e0004847. | Show Abstract | Read more

BACKGROUND: The environmental bacterium Burkholderia pseudomallei causes the infectious disease melioidosis with a high case-fatality rate in tropical and subtropical regions. Direct pathogen detection can be difficult, and therefore an indirect serological test which might aid early diagnosis is desirable. However, current tests for antibodies against B. pseudomallei, including the reference indirect haemagglutination assay (IHA), lack sensitivity, specificity and standardization. Consequently, serological tests currently do not play a role in the diagnosis of melioidosis in endemic areas. Recently, a number of promising diagnostic antigens have been identified, but a standardized, easy-to-perform clinical laboratory test for sensitive multiplex detection of antibodies against B. pseudomallei is still lacking. METHODS AND PRINCIPAL FINDINGS: In this study, we developed and validated a protein microarray which can be used in a standard 96-well format. Our array contains 20 recombinant and purified B. pseudomallei proteins, previously identified as serodiagnostic candidates in melioidosis. In total, we analyzed 196 sera and plasmas from melioidosis patients from northeast Thailand and 210 negative controls from melioidosis-endemic and non-endemic regions. Our protein array clearly discriminated between sera from melioidosis patients and controls with a specificity of 97%. Importantly, the array showed a higher sensitivity than did the IHA in melioidosis patients upon admission (cut-off IHA titer ≥1:160: IHA 57.3%, protein array: 86.7%; p = 0.0001). Testing of sera from single patients at 0, 12 and 52 weeks post-admission revealed that protein antigens induce either a short- or long-term antibody response. CONCLUSIONS: Our protein array provides a standardized, rapid, easy-to-perform test for the detection of B. pseudomallei-specific antibody patterns. Thus, this system has the potential to improve the serodiagnosis of melioidosis in clinical settings. Moreover, our high-throughput assay might be useful for the detection of anti-B. pseudomallei antibodies in epidemiological studies. Further studies are needed to elucidate the clinical and diagnostic significance of the different antibody kinetics observed during melioidosis.

Beardsley J, Wolbers M, Day JN, CryptoDex Investigators. 2016. Dexamethasone in Cryptococcal Meningitis. N Engl J Med, 375 (2), pp. 189-190. | Citations: 1 (Scopus) | Read more

Beardsley J, Wolbers M, Day JN. 2016. Dexamethasone in Cryptococcal Meningitis REPLY NEW ENGLAND JOURNAL OF MEDICINE, 375 (2), pp. 189-190.

Arabi YM, Al-Enezi F, Longuere K-S, Balkhy HH, Al-Sultan M, Al-Omari A, Al-Hameed FM, Carson G, Shindo N, Fowler R. 2016. Feasibility of a randomized controlled trial to assess treatment of Middle East Respiratory Syndrome Coronavirus (MERS-CoV) infection in Saudi Arabia: a survey of physicians. BMC Anesthesiol, 16 (1), pp. 36. | Citations: 2 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: The Middle East Respiratory Syndrome coronavirus (MERS-CoV) is an emerging respiratory pathogen with a high mortality rate and no specific treatments available to date. The purpose of this study was to determine the feasibility of conducting a randomized controlled trial (RCT) of convalescent plasma therapy for MERS-CoV-infected patients by using MERS-CoV-specific convalescent plasma obtained from previously recovered patients. METHODS: A survey was adapted from validated questionnaire originally aimed to measure network capacities and capabilities within the International Severe Acute Respiratory and emerging Infection Consortium (ISARIC). The questionnaire was modified for this study to include 26 items that were divided into three main domains of interest: (1) the ability to care for critically ill MERS-CoV patients; (2) laboratory capacity to diagnose MERS-CoV and blood bank ability to prepare convalescent plasma; and (3), research capacity to conduct randomized controlled trials. The questionnaire was emailed to physicians. RESULTS: Of 582 physicians who were invited to the survey, 327 responded (56.2 %). The professional focus of the majority of respondents was critical care (106/249 (43 %)), pediatrics (59/249, (24 %)) or internal medicine (52/249 (21 %)) but none was blood banking. Nearly all respondents (251/263 (95 %)) reported to have access to ICU facilities within their institutions. Most respondents (219/270 (81 %)) reported that intensivists were the most physician group responsible for treatment decisions about critically ill SARI patients. While 125/165 respondents (76 %) reported that they conduct research in ICUs, and 80/161 (49.7 %) had been involved in the conduct of RCTs, including using a placebo comparison (60/161 (37 %)), only 49/226 (21 %) of respondents regularly participated in research networks. CONCLUSIONS: Our survey indicated that in the Kingdom of Saudi Arabia (KSA), ICUs are the most likely clinical locations for conducting a clinical trial of convalescent plasma therapy for MERS-CoV, and that most ICUs have experience with such research designs.

Howes RE, Battle KE, Mendis KN, Smith DL, Cibulskis RE, Baird JK, Hay SI. 2016. Global Epidemiology of Plasmodium vivax. Am J Trop Med Hyg, 95 (6 Suppl), pp. 15-34. | Citations: 22 (Scopus) | Show Abstract | Read more

Plasmodium vivax is the most widespread human malaria, putting 2.5 billion people at risk of infection. Its unique biological and epidemiological characteristics pose challenges to control strategies that have been principally targeted against Plasmodium falciparum Unlike P. falciparum, P. vivax infections have typically low blood-stage parasitemia with gametocytes emerging before illness manifests, and dormant liver stages causing relapses. These traits affect both its geographic distribution and transmission patterns. Asymptomatic infections, high-risk groups, and resulting case burdens are described in this review. Despite relatively low prevalence measurements and parasitemia levels, along with high proportions of asymptomatic cases, this parasite is not benign. Plasmodium vivax can be associated with severe and even fatal illness. Spreading resistance to chloroquine against the acute attack, and the operational inadequacy of primaquine against the multiple attacks of relapse, exacerbates the risk of poor outcomes among the tens of millions suffering from infection each year. Without strategies accounting for these P. vivax-specific characteristics, progress toward elimination of endemic malaria transmission will be substantially impeded.

Opondo C, Allen E, Todd J, English M. 2016. The Paediatric Admission Quality of Care (PAQC) score: designing a tool to measure the quality of early inpatient paediatric care in a low-income setting. Trop Med Int Health, 21 (10), pp. 1334-1345. | Citations: 2 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Evaluating clinician compliance with recommended steps in clinical guidelines provides one measure of quality of process of care but can result in a multiplicity of indicators across illnesses, making it problematic to produce any summative picture of process quality, information that may be most useful to policy-makers and managers. OBJECTIVE: We set out to develop a clinically logical summative measure of the quality of care provided to children admitted to hospital in Kenya spanning the three diagnoses present in 60% or more of admissions that would provide a patient-level measure of quality of care in the face of comorbidity. METHODS: We developed a conceptual model of care based on three domains: assessment, diagnosis and treatment of illnesses. Individual items within domains correspond to recommended processes of care within national clinical practice guidelines. Summative scores were created to reduce redundancy and enable aggregation across illnesses while maintaining a clear link to clinical domains and our conceptual model. The potential application of the score was explored using data from more than 12 000 children from eight hospitals included in a prior intervention study in Kenya. RESULTS: Summative scores obtained from items representing discrete clinical decision points reduced redundancy, aided balance of score contribution across domains and enabled direct comparison of disease-specific scores and the calculation of scores for children with comorbidity. CONCLUSION: This work describes the development of a summative Paediatric Admission Quality of Care score measured at the patient level that spans three common diseases. The score may be an efficient tool for assessing quality with an ability to adjust for case mix or other patient-level factors if needed. The score principles may have applicability to multiple illnesses and settings. Future analysis will be needed to validate the score.

Winterberg M, Kirk K. 2016. A high-sensitivity HPLC assay for measuring intracellular Na(+) and K(+) and its application to Plasmodium falciparum infected erythrocytes. Sci Rep, 6 (1), pp. 29241. | Show Abstract | Read more

The measurement of intracellular ion concentrations, and the screening of chemical agents to identify molecules targeting ion transport, has traditionally involved low-throughput techniques. Here we present a novel HPLC method that allows the rapid, high-sensitivity measurement of cell Na(+) and K(+) content, demonstrating its utility by monitoring the ionic changes induced in the intracellular malaria parasite by the new spiroindolone antimalarial KAE609.

Moore CE, Elwin K, Phot N, Seng C, Mao S, Suy K, Kumar V, Nader J, Bousfield R, Perera S et al. 2016. Molecular Characterization of Cryptosporidium Species and Giardia duodenalis from Symptomatic Cambodian Children. PLoS Negl Trop Dis, 10 (7), pp. e0004822. | Citations: 5 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: In a prospective study, 498 single faecal samples from children aged under 16 years attending an outpatient clinic in the Angkor Hospital for Children, northwest Cambodia, were examined for Cryptosporidium oocysts and Giardia cysts using microscopy and molecular assays. METHODOLOGY/PRINCIPAL FINDINGS: Cryptosporidium oocysts were detected in 2.2% (11/498) of samples using microscopy and in 7.7% (38/498) with molecular tests. Giardia duodenalis cysts were detected in 18.9% (94/498) by microscopy and 27.7% (138/498) by molecular tests; 82% of the positive samples (by either method) were from children aged 1-10 years. Cryptosporidium hominis was the most common species of Cryptosporidium, detected in 13 (34.2%) samples, followed by Cryptosporidium meleagridis in 9 (23.7%), Cryptosporidium parvum in 8 (21.1%), Cryptosporidium canis in 5 (13.2%), and Cryptosporidium suis and Cryptosporidium ubiquitum in one sample each. Cryptosporidium hominis and C. parvum positive samples were subtyped by sequencing the GP60 gene: C. hominis IaA16R6 and C. parvum IIeA7G1 were the most abundant subtypes. Giardia duodenalis was typed using a multiplex real-time PCR targeting assemblages A and B. Assemblage B (106; 76.8% of all Giardia positive samples) was most common followed by A (12.3%) and mixed infections (5.1%). Risk factors associated with Cryptosporidium were malnutrition (AOR 9.63, 95% CI 1.67-55.46), chronic medical diagnoses (AOR 4.51, 95% CI 1.79-11.34) and the presence of birds in the household (AOR 2.99, 95% CI 1.16-7.73); specifically C. hominis (p = 0.03) and C. meleagridis (p<0.001) were associated with the presence of birds. The use of soap was protective against Giardia infection (OR 0.74, 95% CI 0.58-0.95). CONCLUSIONS/SIGNIFICANCE: This is the first report to describe the different Cryptosporidium species and subtypes and Giardia duodenalis assemblages in Cambodian children. The variety of Cryptosporidium species detected indicates both anthroponotic and zoonotic transmission in this population. Interventions to improve sanitation, increase hand washing after defecation and before preparing food and promote drinking boiled water may reduce the burden of these two parasites.

Nguyen AT, Tran TT, Hoang VMT, Nghiem NM, Le NNT, Le TTM, Phan QT, Truong KH, Le NNT, Ho VL et al. 2016. Development and evaluation of a non-ribosomal random PCR and next-generation sequencing based assay for detection and sequencing of hand, foot and mouth disease pathogens. Virol J, 13 (1), pp. 125. | Citations: 4 (Scopus) | Show Abstract | Read more

BACKGROUND: Hand, foot and mouth disease (HFMD) has become a major public health problem across the Asia-Pacific region, and is commonly caused by enterovirus A71 (EV-A71) and coxsackievirus A6 (CV-A6), CV-A10 and CV-A16. Generating pathogen whole-genome sequences is essential for understanding their evolutionary biology. The frequent replacements among EV serotypes and a limited numbers of available whole-genome sequences hinder the development of overlapping PCRs for whole-genome sequencing. We developed and evaluated a non-ribosomal random PCR (rPCR) and next-generation sequencing based assay for sequence-independent whole-genome amplification and sequencing of HFMD pathogens. A total of 16 EV-A71/CV-A6/CV-A10/CV-A16 PCR positive rectal/throat swabs (Cp values: 20.9-33.3) were used for assay evaluation. RESULTS: Our assay evidently outperformed the conventional rPCR in terms of the total number of EV-A71 reads and the percentage of EV-A71 reads: 2.6 % (1275/50,000 reads) vs. 0.1 % (31/50,000) and 6 % (3008/50,000) vs. 0.9 % (433/50,000) for two samples with Cp values of 30 and 26, respectively. Additionally the assay could generate genome sequences with the percentages of coverage of 94-100 % of 4 different enterovirus serotypes in 73 % of the tested samples, representing the first whole-genome sequences of CV-A6/10/16 from Vietnam, and could assign correctly serotyping results in 100 % of 24 tested specimens. In all but three the obtained consensuses of two replicates from the same sample were 100 % identical, suggesting that our assay is highly reproducible. CONCLUSIONS: In conclusion, we have successfully developed a non-ribosomal rPCR and next-generation sequencing based assay for sensitive detection and direct whole-genome sequencing of HFMD pathogens from clinical samples.

Nduati EW, Nkumama IN, Gambo FK, Muema DM, Knight MG, Hassan AS, Jahangir MN, Etyang TJ, Berkley JA, Urban BC. 2016. HIV-Exposed Uninfected Infants Show Robust Memory B-Cell Responses in Spite of a Delayed Accumulation of Memory B Cells: an Observational Study in the First 2 Years of Life. Clin Vaccine Immunol, 23 (7), pp. 576-585. | Citations: 2 (Web of Science Lite) | Show Abstract | Read more

Improved HIV care has led to an increase in the number of HIV-exposed uninfected (HEU) infants born to HIV-infected women. Although they are uninfected, these infants experience increased morbidity and mortality. One explanation may be that their developing immune system is altered by HIV exposure, predisposing them to increased postnatal infections. We explored the impact of HIV exposure on the B-cell compartment by determining the B-cell subset distribution, the frequency of common vaccine antigen-specific memory B cells (MBCs), and the levels of antibodies to the respective antigens in HEU and HIV-unexposed uninfected (HUU) infants born to uninfected mothers, using flow cytometry, a B-cell enzyme-linked immunosorbent spot assay, and an enzyme-linked immunosorbent assay, respectively, during the first 2 years of life. For the majority of the B-cell subsets, there were no differences between HEU and HUU infants. However, HIV exposure was associated with a lower proportion of B cells in general and MBCs in particular, largely due to a lower proportion of unswitched memory B cells. This reduction was maintained even after correcting for age. These phenotypic differences in the MBC compartment did not affect the ability of HEU infants to generate recall responses to previously encountered antigens or reduce the antigen-specific antibody levels at 18 months of life. Although HIV exposure was associated with a transient reduction in the proportion of MBCs, we found that the ability of HEU infants to mount robust MBC and serological responses was unaffected.

Van Pham T, Pham Nguyen P, Nguyen Duc Khanh T, Nguyen Thanh Thuy N, Nguyen Thuy Nha C, Pouplin T, Farrar J, Thwaites GE, Tran Tinh H. 2016. An HPLC method with diode array detector for the simultaneous quantification of chloroquine and desethylchloroquine in plasma and whole blood samples from Plasmodium vivax patients in Vietnam, using quinine as an internal standard. Biomed Chromatogr, 30 (7), pp. 1104-1111. | Show Abstract | Read more

A sensitive, simple method for quantification of chloroquine (CQ) and desethylchloroquine (MCQ) in whole blood and plasma from Plasmodium vivax patients has been developed using HPLC with diode array detection (DAD). Solid-phase extraction on Isolute-96-CBA was employed to process 100 μL of plasma/whole blood samples. CQ, MCQ and quinine were separated using a mobile phase of phosphate buffer 25 mm, pH 2.60-acetonitrile (88:12, v/v) with 2 mm sodium perchlorate on a Zorbax SB-CN 150 × 4.6 mm, 5 μm column at a flow rate of 1.2 mL/min, at ambient temperature in 10 min, with the DAD wavelength of 343 nm. The method was linear over the range of 10-5000 ng/mL for both CQ and MCQ in plasma and whole blood. The limit of detection was 4 ng/mL and limit of quantification was 10 ng/mL in both plasma and blood for CQ and MCQ. The intra-, inter- and total assay precision were <10% for CQ and MCQ in plasma and whole blood. In plasma, the accuracies varied between 101 and 103%, whereas in whole blood, the accuracies ranged from 97.0 to 102% for CQ and MCQ. The method is an ideal technique with simple facilities and instruments, bringing about good separation in comparison with previous methods. © 2016 The Authors Biomedical Chromatography Published by John Wiley & Sons Ltd.

Sigera PC, Tunpattu TMUS, Jayashantha TP, De Silva AP, Athapattu PL, Dondorp A, Haniffa R. 2016. National Profile of Physical Therapists in Critical Care Units of Sri Lanka: Lower Middle-Income Country. Phys Ther, 96 (7), pp. 933-939. | Citations: 2 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: The availability and role of physical therapists in critical care is variable in resource-poor settings, including lower middle-income countries. OBJECTIVE: The aim of this study was to determine: (1) the availability of critical care physical therapist services, (2) the equipment and techniques used and needed, and (3) the training and continuous professional development of physical therapists. METHODS: All physical therapists working in critical care units (CCUs) of state hospitals in Sri Lanka were contacted. The study tool used was an interviewer-administered telephone questionnaire. RESULTS: The response rate was 100% (N=213). Sixty-one percent of the physical therapists were men. Ninety-four percent of the respondents were at least diploma holders in physical therapy, and 6% had non-physical therapy degrees. Most (n=145, 68%) had engaged in some continuous professional development in the past year. The majority (n=119, 56%) attended to patients after referral from medical staff. Seventy-seven percent, 98%, and 96% worked at nights, on weekends, and on public holidays, respectively. Physical therapists commonly perform manual hyperinflation, breathing exercises, manual airway clearance techniques, limb exercises, mobilization, positioning, and postural drainage in the CCUs. Lack of specialist training, lack of adequate physical therapy staff numbers, a heavy workload, and perceived lack of infection control in CCUs were the main difficulties they identified. LIMITATIONS: Details on the proportions of time spent by the physical therapists in the CCUs, wards, or medical departments were not collected. CONCLUSIONS: The availability of physical therapist services in CCUs in Sri Lanka, a lower middle-income country, was comparable to that in high-income countries, as per available literature, in terms of service availability and staffing, although the density of physical therapists remained very low, critical care training was limited, and resource limitations to physical therapy practices were evident.

Nguyen NT, Nguyen HM, Nguyen CV, Nguyen TV, Nguyen MT, Thai HQ, Ho MH, Thwaites G, Ngo HT, Baker S, Carrique-Mas J. 2016. Use of Colistin and Other Critical Antimicrobials on Pig and Chicken Farms in Southern Vietnam and Its Association with Resistance in Commensal Escherichia coli Bacteria. Appl Environ Microbiol, 82 (13), pp. 3727-3735. | Citations: 21 (Scopus) | Show Abstract | Read more

UNLABELLED: Antimicrobial resistance (AMR) is a global health problem, and emerging semi-intensive farming systems in Southeast Asia are major contributors to the AMR burden. We accessed 12 pig and chicken farms at key stages of production in Tien Giang Province, Vietnam, to measure antimicrobial usage and to investigate the prevalence of AMR to five critical antimicrobials (β-lactams, third-generation cephalosporins, quinolones, aminoglycosides, and polymyxins) and their corresponding molecular mechanisms among 180 Escherichia coli isolates. Overall, 94.7 mg (interquartile range [IQR], 65.3 to 151.1) and 563.6 mg (IQR, 398.9 to 943.6) of antimicrobials was used to produce 1 kg (live weight) of chicken and pig, respectively. A median of 3 (out of 8) critical antimicrobials were used on pig farms. E. coli isolates exhibited a high prevalence of resistance to ampicillin (97.8% and 94.4% for chickens and pigs, respectively), ciprofloxacin (73.3% and 21.1%), gentamicin (42.2% and 35.6%), and colistin (22.2% and 24.4%). The prevalence of a recently discovered colistin resistance gene, mcr-1, was 19 to 22% and had strong agreement with phenotypic colistin resistance. We conducted plasmid conjugation experiments with 37 mcr-1 gene-positive E. coli isolates and successfully observed transfer of the gene in 54.0% of isolates through a plasmid of approximately 63 kb, consistent with one recently identified in China. We found no significant correlation between total use of antimicrobials at the farm level and AMR. These data provide additional insight into the role of mcr-1 in colistin resistance on farms and outline the dynamics of phenotypic and genotypic AMR in semi-intensive farming systems in Vietnam. IMPORTANCE: Our study provides accurate baseline information on levels of antimicrobial use, as well as on the dynamics of phenotypic and genotypic resistance for antimicrobials of critical importance among E. coli over the different stages of production in emerging pig and poultry production systems in Vietnam. E. coli isolates showed a high prevalence of resistance (>20%) to critically important antimicrobials, such as colistin, ciprofloxacin, and gentamicin. The underlying genetic mechanisms identified for colistin (the mcr-1 gene) and quinolone (gyrA gene mutations) are likely to play a major role in AMR to those compounds. Conjugation experiments led to the identification of a 63-kb plasmid, similar to one recently identified in China, as the potential carrier of the mcr-1 gene. These results should encourage greater restrictions of such antimicrobials in Southeast Asian farming systems.

Pholwat S, Sakai F, Turner P, Vidal JE, Houpt ER. 2016. Development of a TaqMan Array Card for Pneumococcal Serotyping on Isolates and Nasopharyngeal Samples. J Clin Microbiol, 54 (7), pp. 1842-1850. | Citations: 3 (Web of Science Lite) | Show Abstract | Read more

Streptococcus pneumoniae is both a commensal and a major pathogen that causes invasive disease in people of all ages. The introduction of serotype-specific pneumococcal vaccines has reduced the burden of disease but has also led to replacement with new strains; thus, serotyping remains important for vaccine-related disease surveillance. Conventional serotyping methods are laborious and expensive. We developed an easy-to-perform genotypic TaqMan array card (TAC) to identify S. pneumoniae strains, including lytA-based sequences, and 53 sequence-specific PCRs to identify 74 serotypes/serogroups covering all current vaccine types as well as prevalent nonvaccine types. The TAC method was evaluated on 146 clinical S. pneumoniae isolates and 13 nonpneumococcal species that naturally inhabit the upper respiratory tract and yielded 97% (142/146) sensitivity and 100% (13/13) specificity versus results of standard Quellung serotyping. The calculated limit of detection was 20 to 200 fg (∼8 to 84 genome equivalents) per reaction. On 23 blinded nasopharyngeal specimens that were pneumococcus culture positive, the TAC pan-pneumococcus lytA assay was positive in 21 (91% sensitivity versus culture). On TAC lytA-positive specimens, a serotype result was obtained on 86%, and the result was 95% accurate versus the subsequent culture's Quellung result. TAC also detected mixed serotypes in two specimens where Quellung detected only the predominant serotype. This TAC method yields fast and comprehensive serotyping compared to the standard method and may be useful on direct specimens.

Hoa LNM, Mai LQ, Bryant JE, Thai PQ, Hang NLK, Yen NTT, Duong TN, Thoang DD, Horby P, Werheim HFL, Fox A. 2016. Association between Hemagglutinin Stem-Reactive Antibodies and Influenza A/H1N1 Virus Infection during the 2009 Pandemic. J Virol, 90 (14), pp. 6549-6556. | Citations: 2 (Scopus) | Show Abstract | Read more

UNLABELLED: The discovery of influenza virus broadly neutralizing (BrN) antibodies prompted efforts to develop universal vaccines. Influenza virus stem-reactive (SR) broadly neutralizing antibodies have been detected by screening antibody phage display libraries. However, studies of SR BrN antibodies in human serum, and their association with natural infection, are limited. To address this, pre- and postpandemic sera from a prospective community cohort study in Vietnam were assessed for antibodies that inhibit SR BrN monoclonal antibody (MAb) (C179) binding to H1N1 pandemic 2009 virus (H1N1pdm09). Of 270 households, 33 with at least one confirmed H1N1pdm09 illness or at least two seroconverters were included. The included households comprised 71 infected and 41 noninfected participants. Sera were tested as 2-fold dilutions between 1:5 and 1:40. Fifty percent C179 inhibition (IC50) titers did not exceed 10, although both IC50 titers and percent C179 inhibition by sera diluted 1:5 or 1:10 correlated with hemagglutination inhibition (HI) and microneutralization (MN) titers (all P < 0.001). Thirteen (12%) participants had detectable prepandemic IC50 titers, but only one reached a titer of 10. This proportion increased to 44% after the pandemic, when 39 participants had a titer of 10, and 67% of infected compared to 44% of noninfected had detectable IC50 titers (P < 0.001). The low levels of SR antibodies in prepandemic sera were not associated with subsequent H1N1pdm09 infection (P = 0.241), and the higher levels induced by H1N1pdm09 infection returned to prepandemic levels within 2 years. The findings indicate that natural infection induces only low titers of SR antibodies that are not sustained. IMPORTANCE: Universal influenza vaccines could have substantial health and economic benefits. The focus of universal vaccine research has been to induce antibodies that prevent infection by diverse influenza virus strains. These so-called broadly neutralizing antibodies are readily detected in mice and ferrets after infection with a series of distinct influenza virus strains. The 2009 H1N1 pandemic provided an opportunity to investigate whether infection with a novel strain induced broadly neutralizing antibodies in humans. We found that broadly neutralizing antibodies were induced, but levels were low and poorly maintained. This could represent an obstacle for universal vaccine development and warrants further investigation.

White NJ. 2016. Can new treatment developments combat resistance in malaria? Expert Opin Pharmacother, 17 (10), pp. 1303-1307. | Citations: 11 (Web of Science Lite) | Read more

Cheah PY, White NJ. 2016. Antimalarial mass drug administration: ethical considerations. Int Health, 8 (4), pp. 235-238. | Citations: 5 (Web of Science Lite) | Show Abstract | Read more

Falciparum malaria is a major cause of death and illness in tropical countries, particularly in childhood. In endemic countries, a significant proportion of the community is infected with malaria asymptomatically. One promising way to eliminate malaria is to give the entire population malaria treatment. This is called mass drug administration (MDA) and it raises a number of ethical issues, as possible long-term benefits are uncertain. The effectiveness of MDA is critically dependent on level of participation, so the promised benefits to the community can be annulled by non-participation of a small number of individuals. These potential benefits range a wide spectrum, from the permanent elimination of malaria (success) to a transient reduction in the prevalence of infection and the incidence of illness (failure). The drawbacks of MDA are: inconvenience, potential toxicity, loss of confidence in the elimination campaign, possible drug resistance (though highly unlikely), and the potential for a rebound of malaria illness (if immunity is lost and malaria is reintroduced later). Other ethical issues are related to balancing individual and public health interests, and potentially limiting individual autonomy by making MDA compulsory.

Olotu A, Fegan G, Wambua J, Nyangweso G, Leach A, Lievens M, Kaslow DC, Njuguna P, Marsh K, Bejon P. 2016. Seven-Year Efficacy of RTS,S/AS01 Malaria Vaccine among Young African Children. N Engl J Med, 374 (26), pp. 2519-2529. | Citations: 35 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: The candidate malaria vaccine RTS,S/AS01 is being evaluated in order to inform a decision regarding its inclusion in routine vaccination schedules. METHODS: We conducted 7 years of follow-up in children who had been randomly assigned, at 5 to 17 months of age, to receive three doses of either the RTS,S/AS01 vaccine or a rabies (control) vaccine. The end point was clinical malaria (temperature of ≥37.5°C and infection with Plasmodium falciparum of >2500 parasites per cubic millimeter). In an analysis that was not prespecified, the malaria exposure of each child was estimated with the use of information on the prevalence of malaria among residents within a 1-km radius of the child's home. Vaccine efficacy was defined as 1 minus the hazard ratio or the incidence-rate ratio, multiplied by 100, in the RTS,S/AS01 group versus the control group. RESULTS: Over 7 years of follow-up, we identified 1002 episodes of clinical malaria among 223 children randomly assigned to the RTS,S/AS01 group and 992 episodes among 224 children randomly assigned to the control group. The vaccine efficacy, as assessed by negative binomial regression, was 4.4% (95% confidence interval [CI], -17.0 to 21.9; P=0.66) in the intention-to-treat analysis and 7.0% (95% CI, -14.5 to 24.6; P=0.52) in the per-protocol analysis. Vaccine efficacy waned over time (P=0.006 for the interaction between vaccination and time), including negative efficacy during the fifth year among children with higher-than-average exposure to malaria parasites (intention-to-treat analysis: -43.5%; 95% CI, -100.3 to -2.8 [P=0.03]; per-protocol analysis: -56.8%; 95% CI, -118.7 to -12.3 [P=0.008]). CONCLUSIONS: A three-dose vaccination with RTS,S/AS01 was initially protective against clinical malaria, but this result was offset by rebound in later years in areas with higher-than-average exposure to malaria parasites. (Funded by the PATH Malaria Vaccine Initiative and others; number, NCT00872963.).

Cerny D, Thi Le DH, The TD, Zuest R, Kg S, Velumani S, Khor CC, Mori L, Simmons CP, Poidinger M et al. 2016. Complete human CD1a deficiency on Langerhans cells due to a rare point mutation in the coding sequence. J Allergy Clin Immunol, 138 (6), pp. 1709-1712.e11. | Citations: 1 (Web of Science Lite) | Read more

Pitzer VE, Aguas R, Riley S, Loeffen WLA, Wood JLN, Grenfell BT. 2016. High turnover drives prolonged persistence of influenza in managed pig herds. J R Soc Interface, 13 (119), pp. 20160138-20160138. | Citations: 4 (Scopus) | Show Abstract | Read more

Pigs have long been hypothesized to play a central role in the emergence of novel human influenza A virus (IAV) strains, by serving as mixing vessels for mammalian and avian variants. However, the key issue of viral persistence in swine populations at different scales is ill understood. We address this gap using epidemiological models calibrated against seroprevalence data from Dutch finishing pigs to estimate the 'critical herd size' (CHS) for IAV persistence. We then examine the viral phylogenetic evidence for persistence by comparing human and swine IAV. Models suggest a CHS of approximately 3000 pigs above which influenza was likely to persist, i.e. orders of magnitude lower than persistence thresholds for IAV and other acute viruses in humans. At national and regional scales, we found much stronger empirical signatures of prolonged persistence of IAV in swine compared with human populations. These striking levels of persistence in small populations are driven by the high recruitment rate of susceptible piglets, and have significant implications for management of swine and for overall patterns of genetic diversity of IAV.

Mogeni P, Williams TN, Fegan G, Nyundo C, Bauni E, Mwai K, Omedo I, Njuguna P, Newton CR, Osier F et al. 2016. Age, Spatial, and Temporal Variations in Hospital Admissions with Malaria in Kilifi County, Kenya: A 25-Year Longitudinal Observational Study. PLoS Med, 13 (6), pp. e1002047. | Citations: 7 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Encouraging progress has been seen with reductions in Plasmodium falciparum malaria transmission in some parts of Africa. Reduced transmission might lead to increasing susceptibility to malaria among older children due to lower acquired immunity, and this has implications for ongoing control strategies. METHODS AND FINDINGS: We conducted a longitudinal observational study of children admitted to Kilifi County Hospital in Kenya and linked it to data on residence and insecticide-treated net (ITN) use. This included data from 69,104 children aged from 3 mo to 13 y admitted to Kilifi County Hospital between 1 January 1990 and 31 December 2014. The variation in malaria slide positivity among admissions was examined in logistic regression models using the following predictors: location of the residence, calendar time, the child's age, ITN use, and the enhanced vegetation index (a proxy for soil moisture). The proportion of malaria slide-positive admissions declined from 0.56 (95% confidence interval [CI] 0.54-0.58) in 1998 to 0.07 (95% CI 0.06-0.08) in 2009 but then increased again through to 0.24 (95% CI 0.22-0.25) in 2014. Older children accounted for most of the increase after 2009 (0.035 [95% CI 0.030-0.040] among young children compared to 0.22 [95% CI 0.21-0.23] in older children). There was a nonlinear relationship between malaria risk and prevalence of ITN use within a 2 km radius of an admitted child's residence such that the predicted malaria positive fraction varied from ~0.4 to <0.1 as the prevalence of ITN use varied from 20% to 80%. In this observational analysis, we were unable to determine the cause of the decline in malaria between 1998 and 2009, which pre-dated the dramatic scale-up in ITN distribution and use. CONCLUSION: Following a period of reduced transmission, a cohort of older children emerged who have increased susceptibility to malaria. Further reductions in malaria transmission are needed to mitigate the increasing burden among older children, and universal ITN coverage is a promising strategy to achieve this goal.

von Seidlein L, Knudsen J. 2016. Malaria Epidemiology in Kilifi, Kenya during the 21st Century: What Next? PLoS Med, 13 (6), pp. e1002048. | Citations: 1 (Web of Science Lite) | Show Abstract | Read more

Lorenz von Seidlein and Jakob Knudsen discuss the changes in malaria incidence recorded at a single site in Africa over 25 years, along with future implications for disease prevention.

Pearson RD, Amato R, Auburn S, Miotto O, Almagro-Garcia J, Amaratunga C, Suon S, Mao S, Noviyanti R, Trimarsanto H et al. 2016. Genomic analysis of local variation and recent evolution in Plasmodium vivax. Nat Genet, 48 (8), pp. 959-964. | Citations: 31 (Scopus) | Show Abstract | Read more

The widespread distribution and relapsing nature of Plasmodium vivax infection present major challenges for the elimination of malaria. To characterize the genetic diversity of this parasite in individual infections and across the population, we performed deep genome sequencing of >200 clinical samples collected across the Asia-Pacific region and analyzed data on >300,000 SNPs and nine regions of the genome with large copy number variations. Individual infections showed complex patterns of genetic structure, with variation not only in the number of dominant clones but also in their level of relatedness and inbreeding. At the population level, we observed strong signals of recent evolutionary selection both in known drug resistance genes and at new loci, and these varied markedly between geographical locations. These findings demonstrate a dynamic landscape of local evolutionary adaptation in the parasite population and provide a foundation for genomic surveillance to guide effective strategies for control and elimination of P. vivax.

Julé AM, Vaillant M, Lang TA, Guérin PJ, Olliaro PL. 2016. The Schistosomiasis Clinical Trials Landscape: A Systematic Review of Antischistosomal Treatment Efficacy Studies and a Case for Sharing Individual Participant-Level Data (IPD). PLoS Negl Trop Dis, 10 (6), pp. e0004784. | Citations: 2 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Schistosomiasis control mainly relies on preventive chemotherapy with praziquantel (PZQ) distributed through mass drug administration. With a target of 260 million treatments yearly, reliably assessing and monitoring efficacy is all-important. Recommendations for treatment and control of schistosomiasis are supported by systematic reviews and meta-analyses of aggregated data, which however also point to limitations due to heterogeneity in trial design, analyses and reporting. Some such limitations could be corrected through access to individual participant-level data (IPD), which facilitates standardised analyses. METHODOLOGY: A systematic literature review was conducted to identify antischistosomal drug efficacy studies performed since 2000; including electronic searches of the Cochrane Infectious Diseases Group specialised register and the Cochrane Library, PubMed, CENTRAL and Embase; complemented with a manual search for articles listed in past reviews. Antischistosomal treatment studies with assessment of outcome within 60 days post-treatment were eligible. Meta-data, i.e. study-level characteristics (Schistosoma species, number of patients, drug administered, country, etc.) and efficacy parameters were extracted from published documents to evaluate the scope of an individual-level data sharing platform. PRINCIPAL FINDINGS: Out of 914 documents screened, 90 studies from 26 countries were included, enrolling 20,517 participants infected with Schistosoma spp. and treated with different PZQ regimens or other drugs. Methodologies varied in terms of diagnostic approaches (number of samples and test repeats), time of outcome assessment, and outcome measure (cure rate or egg reduction rate, as an arithmetic or geometric mean), making direct comparison of published data difficult. CONCLUSIONS: This review describes the landscape of schistosomiasis clinical research. The volume of data and the methodological and reporting heterogeneity identified all indicate that there is scope for an individual participant-level database, to allow for standardised analyses.

Pham Thanh D, Thompson CN, Rabaa MA, Sona S, Sopheary S, Kumar V, Moore C, Tran Vu Thieu N, Wijedoru L, Holt KE et al. 2016. The Molecular and Spatial Epidemiology of Typhoid Fever in Rural Cambodia. PLoS Negl Trop Dis, 10 (6), pp. e0004785. | Citations: 3 (Scopus) | Show Abstract | Read more

Typhoid fever, caused by the bacterium Salmonella Typhi, is an endemic cause of febrile disease in Cambodia. The aim of this study was to better understand the epidemiology of pediatric typhoid fever in Cambodia. We accessed routine blood culture data from Angkor Hospital for Children (AHC) in Siem Reap province between 2007 and 2014, and performed whole genome sequencing (WGS) on the isolated bacteria to characterize the S. Typhi population. The resulting phylogenetic information was combined with conventional epidemiological approaches to investigate the spatiotemporal distribution of S. Typhi and population-level risk factors for reported disease. During the study period, there were 262 cases of typhoid within a 100 km radius of AHC, with a median patient age of 8.2 years (IQR: 5.1-11.5 years). The majority of infections occurred during the rainy season, and commune incidences as high as 11.36/1,000 in children aged <15 years were observed over the study period. A population-based risk factor analysis found that access to water within households and increasing distance from Tonle Sap Lake were protective. Spatial mapping and WGS provided additional resolution for these findings, and confirmed that proximity to the lake was associated with discrete spatiotemporal disease clusters. We confirmed the dominance of MDR H58 S. Typhi in this population, and found substantial evidence of diversification (at least seven sublineages) within this single lineage. We conclude that there is a substantial burden of pediatric typhoid fever in rural communes in Cambodia. Our data provide a platform for additional population-based typhoid fever studies in this location, and suggest that this would be a suitable setting in which to introduce a school-based vaccination programme with Vi conjugate vaccines.

Arias A, Watson SJ, Asogun D, Tobin EA, Lu J, Phan MVT, Jah U, Wadoum REG, Meredith L, Thorne L et al. 2016. Rapid outbreak sequencing of Ebola virus in Sierra Leone identifies transmission chains linked to sporadic cases. Virus Evol, 2 (1), pp. vew016. | Show Abstract | Read more

To end the largest known outbreak of Ebola virus disease (EVD) in West Africa and to prevent new transmissions, rapid epidemiological tracing of cases and contacts was required. The ability to quickly identify unknown sources and chains of transmission is key to ending the EVD epidemic and of even greater importance in the context of recent reports of Ebola virus (EBOV) persistence in survivors. Phylogenetic analysis of complete EBOV genomes can provide important information on the source of any new infection. A local deep sequencing facility was established at the Mateneh Ebola Treatment Centre in central Sierra Leone. The facility included all wetlab and computational resources to rapidly process EBOV diagnostic samples into full genome sequences. We produced 554 EBOV genomes from EVD cases across Sierra Leone. These genomes provided a detailed description of EBOV evolution and facilitated phylogenetic tracking of new EVD cases. Importantly, we show that linked genomic and epidemiological data can not only support contact tracing but also identify unconventional transmission chains involving body fluids, including semen. Rapid EBOV genome sequencing, when linked to epidemiological information and a comprehensive database of virus sequences across the outbreak, provided a powerful tool for public health epidemic control efforts.

Thwaites CL, Lundeg G, Dondorp AM, sepsis in resource-limited settings–expert consensus recommendations group of the European Society of Intensive Care Medicine (ESICM) and the Mahidol-Oxford Research Unit (MORU) in Bangkok, Thailand. 2016. Recommendations for infection management in patients with sepsis and septic shock in resource-limited settings. Intensive Care Med, 42 (12), pp. 2040-2042. | Citations: 6 (Scopus) | Read more

Kho S, Marfurt J, Handayuni I, Pava Z, Noviyanti R, Kusuma A, Piera KA, Burdam FH, Kenangalem E, Lampah DA et al. 2016. Characterization of blood dendritic and regulatory T cells in asymptomatic adults with sub-microscopic Plasmodium falciparum or Plasmodium vivax infection. Malar J, 15 (1), pp. 328. | Citations: 2 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Plasmodium falciparum and Plasmodium vivax infections compromise dendritic cell (DC) function and expand regulatory T (Treg) cells in both clinical disease (malaria) and experimental human sub-microscopic infection. Conversely, in asymptomatic microscopy-positive (patent) P. falciparum or P. vivax infection in endemic areas, blood DC increase or retain HLA-DR expression and Treg cells exhibit reduced activation, suggesting that DC and Treg cells contribute to the control of patent asymptomatic infection. The effect of sub-microscopic (sub-patent) asymptomatic Plasmodium infection on DC and Treg cells in malaria-endemic area residents remains unclear. METHODS: In a cross-sectional household survey conducted in Papua, Indonesia, 162 asymptomatic adults were prospectively evaluated for DC and Treg cells using field-based flow cytometry. Of these, 161 individuals (99 %) were assessed retrospectively by polymerase chain reaction (PCR), 19 of whom had sub-microscopic infection with P. falciparum and 15 with sub-microscopic P. vivax infection. Flow cytometric data were re-analysed after re-grouping asymptomatic individuals according to PCR results into negative controls, sub-microscopic and microscopic parasitaemia to examine DC and Treg cell phenotype in sub-microscopic infection. RESULTS: Asymptomatic adults with sub-microscopic P. falciparum or P. vivax infection had DC HLA-DR expression and Treg cell activation comparable to PCR-negative controls. Sub-microscopic P. falciparum infection was associated with lower peripheral CD4(+) T cells and lymphocytes, however sub-microscopic Plasmodium infection had no apparent effect on DC sub-set number or Treg cell frequency. CONCLUSIONS: In contrast to the impairment of DC maturation/function and the activation of Treg cells seen with sub-microscopic parasitaemia in primary experimental human Plasmodium infection, no phenotypic evidence of dysregulation of DC and Treg cells was observed in asymptomatic sub-microscopic Plasmodium infection in Indonesian adults. This is consistent with DC and Treg cells retaining their functional capacity in sub-microscopic asymptomatic infection with P. falciparum or P. vivax in malaria-endemic areas.

Kenangalem E, Karyana M, Burdarm L, Yeung S, Simpson JA, Tjitra E, Anstey NM, Poespoprodjo JR, Price RN, Douglas NM. 2016. Plasmodium vivax infection: a major determinant of severe anaemia in infancy. Malar J, 15 (1), pp. 321. | Show Abstract | Read more

BACKGROUND: Most malarious countries outside of Africa are co-endemic for Plasmodium falciparum and Plasmodium vivax. The comparative burden of anaemia in the community caused by these two species is incompletely characterized. METHODS: A three-stage, cross-sectional, community survey was used to determine the proportion of moderate or severe anaemia (haemoglobin <7 g/dL) attributable to patent P. vivax, P. falciparum and mixed parasitaemia in Papua, Indonesia. Adjusted population-attributable fractions were calculated from multivariable logistic regression models. Eight hundred and twenty-five households were surveyed with a total of 5255 occupants, 3890 (74 %) of whom were present and provided a blood sample. Plasmodium falciparum parasitaemia was present in 8.1 % (n = 315) of participants, P. vivax in 6.4 % (n = 250) and mixed infections in 1.9 % (n = 72). Overall, P. falciparum was associated with a mean reduction in haemoglobin of 1.16 g/dL compared to those without patent parasitaemia [95 % confidence interval (95 % CI) 0.91, 1.41 g/dL]. The corresponding values for P. vivax and mixed infections were 0.66 g/dL (95 % CI 0.35, 0.96) and 1.25 g/dL (0.71, 1.80), respectively. Overall, 16.7 % (95 % CI 8.52, 24.2 %) of haemoglobin concentrations <7 g/dL in the community were estimated to be attributable to patent parasitaemia. The fractions for infants and 1-5 years old were 34.4 % (95 % CI -3.30, 58.3 %) and 23.2 % (95 % CI 3.34, 39.0 %), respectively. Plasmodium vivax was associated with a greater than threefold higher attributable fraction of anaemia in infants compared with P. falciparum [27.6 % (95 % CI -3.20, 49.2 %) versus 7.94 % (-5.87, 20.0 %)]. CONCLUSION: Despite comparatively low-level endemicity, malaria is associated with a significant proportion of all cases of community anaemia in southern Papua. Contrary to its benign reputation, P. vivax is an important and preventable risk factor for anaemia during infancy-a probable consequence of relapsing disease prior to the development of immunity.

Reich NG, Lauer SA, Sakrejda K, Iamsirithaworn S, Hinjoy S, Suangtho P, Suthachana S, Clapham HE, Salje H, Cummings DAT, Lessler J. 2016. Challenges in Real-Time Prediction of Infectious Disease: A Case Study of Dengue in Thailand. PLoS Negl Trop Dis, 10 (6), pp. e0004761. | Citations: 3 (Scopus) | Show Abstract | Read more

Epidemics of communicable diseases place a huge burden on public health infrastructures across the world. Producing accurate and actionable forecasts of infectious disease incidence at short and long time scales will improve public health response to outbreaks. However, scientists and public health officials face many obstacles in trying to create such real-time forecasts of infectious disease incidence. Dengue is a mosquito-borne virus that annually infects over 400 million people worldwide. We developed a real-time forecasting model for dengue hemorrhagic fever in the 77 provinces of Thailand. We created a practical computational infrastructure that generated multi-step predictions of dengue incidence in Thai provinces every two weeks throughout 2014. These predictions show mixed performance across provinces, out-performing seasonal baseline models in over half of provinces at a 1.5 month horizon. Additionally, to assess the degree to which delays in case reporting make long-range prediction a challenging task, we compared the performance of our real-time predictions with predictions made with fully reported data. This paper provides valuable lessons for the implementation of real-time predictions in the context of public health decision making.

Toapanta FR, Bernal PJ, Fresnay S, Magder LS, Darton TC, Jones C, Waddington CS, Blohmke CJ, Angus B, Levine MM et al. 2016. Oral Challenge with Wild-Type Salmonella Typhi Induces Distinct Changes in B Cell Subsets in Individuals Who Develop Typhoid Disease. PLoS Negl Trop Dis, 10 (6), pp. e0004766. | Citations: 1 (Web of Science Lite) | Show Abstract | Read more

A novel human oral challenge model with wild-type Salmonella Typhi (S. Typhi) was recently established by the Oxford Vaccine Group. In this model, 104 CFU of Salmonella resulted in 65% of participants developing typhoid fever (referred here as typhoid diagnosis -TD-) 6-9 days post-challenge. TD was diagnosed in participants meeting clinical (oral temperature ≥38°C for ≥12h) and/or microbiological (S. Typhi bacteremia) endpoints. Changes in B cell subpopulations following S. Typhi challenge remain undefined. To address this issue, a subset of volunteers (6 TD and 4 who did not develop TD -NoTD-) was evaluated. Notable changes included reduction in the frequency of B cells (cells/ml) of TD volunteers during disease days and increase in plasmablasts (PB) during the recovery phase (>day 14). Additionally, a portion of PB of TD volunteers showed a significant increase in activation (CD40, CD21) and gut homing (integrin α4β7) molecules. Furthermore, all BM subsets of TD volunteers showed changes induced by S. Typhi infections such as a decrease in CD21 in switched memory (Sm) CD27+ and Sm CD27- cells as well as upregulation of CD40 in unswitched memory (Um) and Naïve cells. Furthermore, changes in the signaling profile of some BM subsets were identified after S. Typhi-LPS stimulation around time of disease. Notably, naïve cells of TD (compared to NoTD) volunteers showed a higher percentage of cells phosphorylating Akt suggesting enhanced survival of these cells. Interestingly, most these changes were temporally associated with disease onset. This is the first study to describe differences in B cell subsets directly related to clinical outcome following oral challenge with wild-type S. Typhi in humans.

Heijman T, Stolte I, Geskus R, Matser A, Davidovich U, Xiridou M, Schim van der Loeff M. 2016. Does online dating lead to higher sexual risk behaviour? A cross-sectional study among MSM in Amsterdam, the Netherlands. BMC Infect Dis, 16 (1), pp. 288. | Citations: 1 (Scopus) | Show Abstract | Read more

BACKGROUND: Men having sex with men (MSM) frequently use the Internet to find sex partners. We examined the association between unprotected anal intercourse (UAI) with partners dated online and with partners dated offline (met elsewhere), and examined whether differences can be explained by self-perceived HIV status of the index and knowledge of partnership characteristics. METHODS: MSM were recruited at the Sexually Transmitted Infections Clinic in Amsterdam, in 2008-2009. Participants completed a questionnaire concerning sexual behaviour. Only men reporting both online and offline casual sex partners were included. We assessed the association between online/offline partner dating and UAI, using random-effects logistic regression analysis. RESULTS: Five hundred seventy-seven men (351 HIV-negative, 153 HIV-positive, and 73 HIV-unaware) reported UAI in 26 % of 878 online, and 23 % of 903 offline casual partnerships. The crude OR of online dating for UAI was 1.36 (95 % CI 1.03-1.81). HIV-positive men were more likely to report UAI than HIV-negative men (49 % vs. 28 % of partnerships). Adjusted for demographic characteristics, online dating had no significant effect on UAI among HIV-negative and HIV status-unaware men, but HIV-positive men were more likely to have UAI with online partners (aOR = 1.65 [95 % CI 1.05-2.57]). After correction for partner and partnership characteristics the effect of online/offline dating on UAI among HIV-positive MSM was reduced and no longer significant. CONCLUSIONS: Online dating was not significantly associated with UAI among HIV-negative MSM. HIV-positive MSM were more likely to practise UAI with partners dated online; however, after correction for partner and partnership characteristics, online partnership acquisition was not associated with a significantly increased risk of UAI.

Inzaule SC, Weidle PJ, Yang C, Ndiege K, Hamers RL, Rinke de Wit TF, Thomas T, Zeh C. 2016. Prevalence and dynamics of the K65R drug resistance mutation in HIV-1-infected infants exposed to maternal therapy with lamivudine, zidovudine and either nevirapine or nelfinavir in breast milk. J Antimicrob Chemother, 71 (6), pp. 1619-1626. | Citations: 1 (Scopus) | Show Abstract | Read more

BACKGROUND: K65R is a relatively rare drug resistance mutation (DRM) selected by the NRTIs tenofovir, didanosine, abacavir and stavudine and confers cross-resistance to all NRTIs except zidovudine. Selection by other NRTIs is uncommon. OBJECTIVES: In this study we investigated the frequency of emergence of the K65R mutation and factors associated with it in HIV-1-infected infants exposed to low doses of maternal lamivudine, zidovudine and either nevirapine or nelfinavir ingested through breast milk, using specimens collected from the Kisumu Breastfeeding Study. METHODS: Plasma specimens with viral load ≥1000 copies/mL collected from HIV-infected infants at 0-1, 2, 6, 14, 24 and 36 weeks of age and maternal samples at delivery were tested for HIV drug resistance using Sanger sequencing of the polymerase gene. Factors associated with K65R emergence were assessed using Fisher's exact test and the Wilcoxon rank-sum test. RESULTS: K65R was detected in samples from 6 of the 24 infants (25%) who acquired HIV-1 infection by the age of 6 months. K65R emerged in half of the infants by 6 weeks and in the rest by 14 weeks of age. None of the mothers at delivery or the infants with a positive genotype at first time of positivity had the K65R mutation. Infants with K65R had low baseline CD4 cell counts (P = 0.014), were more likely to have DRMs earlier (≤6 weeks versus ≥14 weeks, P = 0.007) and were more likely to have multiclass drug resistance (P = 0.035). M184V was the most common mutation associated with K65R emergence. K65R had reverted by 3 months after cessation of breastfeeding. CONCLUSIONS: A high rate of K65R emergence may suggest that ingesting low doses of lamivudine via breast milk could select for this mutation. The presence of this mutation may have a negative impact on future responses to NRTI-based ART. More in vitro studies are, however, needed to establish the molecular mechanism for this selection.

Leung JM, Hong CTT, Trung NHD, Thi HN, Minh CNN, Thi TV, Hong DT, Man DNH, Knowles SCL, Wolbers M et al. 2016. The impact of albendazole treatment on the incidence of viral- and bacterial-induced diarrhea in school children in southern Vietnam: study protocol for a randomized controlled trial. Trials, 17 (1), pp. 279. | Show Abstract | Read more

BACKGROUND: Anthelmintics are one of the more commonly available classes of drugs to treat infections by parasitic helminths (especially nematodes) in the human intestinal tract. As a result of their cost-effectiveness, mass school-based deworming programs are becoming routine practice in developing countries. However, experimental and clinical evidence suggests that anthelmintic treatments may increase susceptibility to other gastrointestinal infections caused by bacteria, viruses, or protozoa. Hypothesizing that anthelmintics may increase diarrheal infections in treated children, we aim to evaluate the impact of anthelmintics on the incidence of diarrheal disease caused by viral and bacterial pathogens in school children in southern Vietnam. METHODS/DESIGN: This is a randomized, double-blinded, placebo-controlled trial to investigate the effects of albendazole treatment versus placebo on the incidence of viral- and bacterial-induced diarrhea in 350 helminth-infected and 350 helminth-uninfected Vietnamese school children aged 6-15 years. Four hundred milligrams of albendazole, or placebo treatment will be administered once every 3 months for 12 months. At the end of 12 months, all participants will receive albendazole treatment. The primary endpoint of this study is the incidence of diarrheal disease assessed by 12 months of weekly active and passive case surveillance. Secondary endpoints include the prevalence and intensities of helminth, viral, and bacterial infections, alterations in host immunity and the gut microbiota with helminth and pathogen clearance, changes in mean z scores of body weight indices over time, and the number and severity of adverse events. DISCUSSION: In order to reduce helminth burdens, anthelmintics are being routinely administered to children in developing countries. However, the effects of anthelmintic treatment on susceptibility to other diseases, including diarrheal pathogens, remain unknown. It is important to monitor for unintended consequences of drug treatments in co-infected populations. In this trial, we will examine how anthelmintic treatment impacts host susceptibility to diarrheal infections, with the aim of informing deworming programs of any indirect effects of mass anthelmintic administrations on co-infecting enteric pathogens. TRIAL REGISTRATION: NCT02597556 . Registered on 3 November 2015.

Berkley JA, Ngari M, Thitiri J, Mwalekwa L, Timbwa M, Hamid F, Ali R, Shangala J, Mturi N, Jones KDJ et al. 2016. Daily co-trimoxazole prophylaxis to prevent mortality in children with complicated severe acute malnutrition: a multicentre, double-blind, randomised placebo-controlled trial. Lancet Glob Health, 4 (7), pp. e464-e473. | Citations: 8 (Scopus) | Show Abstract | Read more

BACKGROUND: Children with complicated severe acute malnutrition (SAM) have a greatly increased risk of mortality from infections while in hospital and after discharge. In HIV-infected children, mortality and admission to hospital are prevented by daily co-trimoxazole prophylaxis, despite locally reported bacterial resistance to co-trimoxazole. We aimed to assess the efficacy of daily co-trimoxazole prophylaxis on survival in children without HIV being treated for complicated SAM. METHODS: We did a multicentre, double-blind, randomised, placebo-controlled study in four hospitals in Kenya (two rural hospitals in Kilifi and Malindi, and two urban hospitals in Mombasa and Nairobi) with children aged 60 days to 59 months without HIV admitted to hospital and diagnosed with SAM. We randomly assigned eligible participants (1:1) to 6 months of either daily oral co-trimoxazole prophylaxis (given as water-dispersible tablets; 120 mg per day for age <6 months, 240 mg per day for age 6 months to 5 years) or matching placebo. Assignment was done with computer-generated randomisation in permuted blocks of 20, stratified by centre and age younger or older than 6 months. Treatment allocation was concealed in opaque, sealed envelopes and patients, their families, and all trial staff were masked to treatment assignment. Children were given recommended medical care and feeding, and followed up for 12 months. The primary endpoint was mortality, assessed each month for the first 6 months, then every 2 months for the second 6 months. Secondary endpoints were nutritional recovery, readmission to hospital, and illness episodes treated as an outpatient. Analysis was by intention to treat. This trial was registered at, number NCT00934492. FINDINGS: Between Nov 20, 2009, and March 14, 2013, we recruited and assigned 1778 eligible children to treatment (887 to co-trimoxazole prophylaxis and 891 to placebo). Median age was 11 months (IQR 7-16 months), 306 (17%) were younger than 6 months, 300 (17%) had oedematous malnutrition (kwashiorkor), and 1221 (69%) were stunted (length-for-age Z score <-2). During 1527 child-years of observation, 122 (14%) of 887 children in the co-trimoxazole group died, compared with 135 (15%) of 891 in the placebo group (unadjusted hazard ratio [HR] 0·90, 95% CI 0·71-1·16, p=0·429; 16·0 vs 17·7 events per 100 child-years observed (CYO); difference -1·7 events per 100 CYO, 95% CI -5·8 to 2·4]). In the first 6 months of the study (while participants received study medication), 63 suspected grade 3 or 4 associated adverse events were recorded among 57 (3%) children; 31 (2%) in the co-trimoxazole group and 32 (2%) in the placebo group (incidence rate ratio 0·98, 95% CI 0·58-1·65). The most common adverse events of these grades were urticarial rash (grade 3, equally common in both groups), neutropenia (grade 4, more common in the co-trimoxazole group), and anaemia (both grades equally common in both groups). One child in the placebo group had fatal toxic epidermal necrolysis with concurrent Pseudomonas aeruginosa bacteraemia. INTERPRETATION: Daily co-trimoxazole prophylaxis did not reduce mortality in children with complicated SAM without HIV. Other strategies need to be tested in clinical trials to reduce deaths in this population. FUNDING: Wellcome Trust, UK.

Heemskerk AD, Bang ND, Thwaites GE. 2016. Therapy for Tuberculous Meningitis. N Engl J Med, 374 (22), pp. 2188-2189. | Read more

Heemskerk AD, Bang ND, Thwaites GE. 2016. Therapy for Tuberculous Meningitis REPLY NEW ENGLAND JOURNAL OF MEDICINE, 374 (22), pp. 2188-2189. | Citations: 1 (Web of Science Lite)

Walther BA, Boëte C, Binot A, By Y, Cappelle J, Carrique-Mas J, Chou M, Furey N, Kim S, Lajaunie C et al. 2016. Biodiversity and health: Lessons and recommendations from an interdisciplinary conference to advise Southeast Asian research, society and policy. Infect Genet Evol, 40 pp. 29-46. | Citations: 5 (Scopus) | Show Abstract | Read more

Southeast Asia is an economic, biodiverse, cultural and disease hotspot. Due to rapid socio-economic and environmental changes, the role of biodiversity and ecosystems for human health ought to be examined and communicated to decision-makers and the public. We therefore summarized the lessons and recommendations from an interdisciplinary conference convened in Cambodia in 2014 to advise Southeast Asian societies on current research efforts, future research needs, and to provide suggestions for improved education, training and science-policy interactions. First, we reviewed several examples of the important role of ecosystems as 'sentinels' in the sense that potentially harmful developments for human health become first apparent in ecosystem components. Other ecosystem services which also benefit human well-being are briefly summarized. Second, we summarized the recommendations of the conference's roundtable discussions and added recent developments in the science-policy interface. The recommendations were organized along five themes: Ethical and legal considerations; implementation of the One Health approach; education, training, and capacity building; future research priorities; and potential science-policy interactions. While the role of biodiversity for human health needs further research, especially for zoonoses and emerging diseases, many direct and indirect benefits to human health are already apparent, but have yet to filter down to the science-policy interface in order to influence legislation and enforcement. Therefore, efforts to strengthen the interface in Southeast Asia should become a high priority in order to strengthen the health and resilience of Southeast Asian societies.

Tabernero P, Parker M, Ravinetto R, Phanouvong S, Yeung S, Kitutu FE, Cheah PY, Mayxay M, Guerin PJ, Newton PN. 2016. Ethical challenges in designing and conducting medicine quality surveys. Trop Med Int Health, 21 (6), pp. 799-806. | Citations: 2 (Web of Science Lite) | Show Abstract | Read more

OBJECTIVES: In this paper we discuss the main ethical challenges related to the conduct of medicine quality surveys and make suggestions on how to address them. METHOD: Most evidence-based information regarding medicine quality derives from surveys. However, existing research ethical guidelines do not provide specific guidance for medicine quality surveys. Hence, those conducting surveys are often left wondering how to judge what counts as best practice. A list of the main ethical challenges in the design and conduct of surveys is presented. RESULTS AND CONCLUSIONS: It is vital that the design and conduct of medicine quality surveys uphold moral and ethical obligations and analyse the ethical implications and consequences of such work. These aspects include the impact on the local availability of and access to medicines; the confidentiality and privacy of the surveyors and the surveyed; questions as to whether outlet staff personnel should be told they are part of a survey; the need of ethical and regulatory approvals; and how the findings should be disseminated. Medicine quality surveys should ideally be conducted in partnership with the relevant national Medicine Regulatory Authorities. An international, but contextually sensitive, model of good ethical practice for such surveys is needed.

Boonyuen U, Chamchoy K, Swangsri T, Saralamba N, Day NPJ, Imwong M. 2016. Detailed functional analysis of two clinical glucose-6-phosphate dehydrogenase (G6PD) variants, G6PDViangchan and G6PDViangchan+Mahidol: Decreased stability and catalytic efficiency contribute to the clinical phenotype. Mol Genet Metab, 118 (2), pp. 84-91. | Citations: 6 (Scopus) | Show Abstract | Read more

Deficiency of glucose-6-phosphate dehydrogenase (G6PD) is an X-linked hereditary genetic defect that is the most common polymorphism and enzymopathy in humans. To investigate functional properties of two clinical variants, G6PDViangchan and G6PDViangchan+Mahidol, these two mutants were created by overlap-extension PCR, expressed in Escherichia coli and purified to homogeneity. We describe an overexpression and purification method to obtain substantial amounts of functionally active protein. The KM for G6P of the two variants was comparable to the KM of the native enzyme, whereas the KM for NADP(+) was increased 5-fold for G6PDViangchan and 8-fold for G6PDViangchan+Mahidol when compared with the native enzyme. Additionally, kcat of the mutant enzymes was markedly reduced, resulting in a 10- and 18-fold reduction in catalytic efficiency for NADP(+) catalysis for G6PDViangchan and G6PDViangchan+Mahidol, respectively. Furthermore, the two variants demonstrated significant reduction in thermostability, but similar susceptibility to trypsin digestion, when compared with the wild-type enzyme. The presence of NADP(+) is shown to improve the stability of G6PD enzymes. This is the first report indicating that protein instability and reduced catalytic efficiency are responsible for the reduced catalytic activity of G6PDViangchan and G6PDViangchan+Mahidol and, as a consequence, contribute to the clinical phenotypes of these two clinical variants.

Watthanaworawit W, Kolakowska E, Hanboonkunupakarn B, Ling C, McGready R. 2016. Scrub typhus infection in pregnancy: the dilemma of diagnosis and treatment in a resource-limited setting. Clin Case Rep, 4 (6), pp. 584-588. | Show Abstract | Read more

To save the life of both mother and fetus, the risks and benefits of the few antibiotics considered effective in the treatment of severe scrub typhus require consideration. In this case, chloramphenicol treatment averted maternal but not fetal mortality. Evidence-based guidelines appropriate for resource-limited endemic areas are required.

Grigg MJ, William T, Menon J, Barber BE, Wilkes CS, Rajahram GS, Edstein MD, Auburn S, Price RN, Yeo TW, Anstey NM. 2016. Efficacy of Artesunate-mefloquine for Chloroquine-resistant Plasmodium vivax Malaria in Malaysia: An Open-label, Randomized, Controlled Trial. Clin Infect Dis, 62 (11), pp. 1403-1411. | Citations: 6 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Chloroquine (CQ)-resistant Plasmodium vivax is increasingly reported throughout southeast Asia. The efficacy of CQ and alternative artemisinin combination therapies (ACTs) for vivax malaria in Malaysia is unknown. METHODS: A randomized, controlled trial of CQ vs artesunate-mefloquine (AS-MQ) for uncomplicated vivax malaria was conducted in 3 district hospitals in Sabah, Malaysia. Primaquine was administered on day 28. The primary outcome was the cumulative risk of treatment failure by day 28 by Kaplan-Meier analysis. RESULTS: From 2012 to 2014, 103 adults and children were enrolled. Treatment failure by day 28 was 61.1% (95% confidence interval [CI], 46.8-75.6) after CQ and 0% (95% CI, 0-.08) following AS-MQ (P < .001), of which 8.2% (95% CI, 2.5-9.6) were early treatment failures. All patients with treatment failure had therapeutic plasma CQ concentrations at day 7. Compared with CQ, AS-MQ was associated with faster parasite clearance (normalized clearance slope, 0.311 vs 0.127; P < .001) and fever clearance (mean, 19.0 vs 37.7 hours; P =001) and with lower risk of anemia at day 28 (odds ratio = 3.7; 95% CI, 1.5-9.3; P =005). Gametocytes were present at day 28 in 23.8% (10/42) of patients following CQ vs none with AS-MQ (P < .001). AS-MQ resulted in lower bed occupancy: 4037 vs 6510 days/1000 patients (incidence rate ratio 0.62; 95% CI, .60-.65; P < .001). One patient developed severe anemia not regarded as related to their AS-MQ treatment. CONCLUSIONS: High-grade CQ-resistant P. vivax is prevalent in eastern Malaysia. AS-MQ is an efficacious ACT for all malaria species. Wider CQ-efficacy surveillance is needed in vivax-endemic regions with earlier replacement with ACT when treatment failure is detected.Clinical Trials Registration NCT01708876.

Yoshida S, Martines J, Lawn JE, Wall S, Souza JP, Rudan I, Cousens S, neonatal health research priority setting group, Aaby P, Adam I et al. 2016. Setting research priorities to improve global newborn health and prevent stillbirths by 2025. J Glob Health, 6 (1), pp. 010508. | Citations: 19 (Scopus) | Show Abstract | Read more

BACKGROUND: In 2013, an estimated 2.8 million newborns died and 2.7 million were stillborn. A much greater number suffer from long term impairment associated with preterm birth, intrauterine growth restriction, congenital anomalies, and perinatal or infectious causes. With the approaching deadline for the achievement of the Millennium Development Goals (MDGs) in 2015, there was a need to set the new research priorities on newborns and stillbirth with a focus not only on survival but also on health, growth and development. We therefore carried out a systematic exercise to set newborn health research priorities for 2013-2025. METHODS: We used adapted Child Health and Nutrition Research Initiative (CHNRI) methods for this prioritization exercise. We identified and approached the 200 most productive researchers and 400 program experts, and 132 of them submitted research questions online. These were collated into a set of 205 research questions, sent for scoring to the 600 identified experts, and were assessed and scored by 91 experts. RESULTS: Nine out of top ten identified priorities were in the domain of research on improving delivery of known interventions, with simplified neonatal resuscitation program and clinical algorithms and improved skills of community health workers leading the list. The top 10 priorities in the domain of development were led by ideas on improved Kangaroo Mother Care at community level, how to improve the accuracy of diagnosis by community health workers, and perinatal audits. The 10 leading priorities for discovery research focused on stable surfactant with novel modes of administration for preterm babies, ability to diagnose fetal distress and novel tocolytic agents to delay or stop preterm labour. CONCLUSION: These findings will assist both donors and researchers in supporting and conducting research to close the knowledge gaps for reducing neonatal mortality, morbidity and long term impairment. WHO, SNL and other partners will work to generate interest among key national stakeholders, governments, NGOs, and research institutes in these priorities, while encouraging research funders to support them. We will track research funding, relevant requests for proposals and trial registers to monitor if the priorities identified by this exercise are being addressed.

James SL, Blacksell SD, Nawtaisong P, Tanganuchitcharnchai A, Smith DJ, Day NPJ, Paris DH. 2016. Antigenic Relationships among Human Pathogenic Orientia tsutsugamushi Isolates from Thailand. PLoS Negl Trop Dis, 10 (6), pp. e0004723. | Citations: 3 (Scopus) | Show Abstract | Read more

BACKGROUND: Scrub typhus is a common cause of undiagnosed febrile illness in certain tropical regions, but can be easily treated with antibiotics. The causative agent, Orientia tsutsugamushi, is antigenically variable which complicates diagnosis and efforts towards vaccine development. METHODOLOGY/PRINCIPAL FINDINGS: This study aimed to dissect the antigenic and genetic relatedness of O. tsutsugamushi strains and investigate sero-diagnostic reactivities by titrating individual patient sera against their O. tsutsugamushi isolates (whole-cell antigen preparation), in homologous and heterologous serum-isolate pairs from the same endemic region in NE Thailand. The indirect immunofluorescence assay was used to titrate Orientia tsutsugamushi isolates and human sera, and a mathematical technique, antigenic cartography, was applied to these data to visualise the antigenic differences and cross-reactivity between strains and sera. No functional or antigen-specific analyses were performed. The antigenic variation found in clinical isolates was much less pronounced than the genetic differences found in the 56kDa type-specific antigen genes. The Karp-like sera were more broadly reactive than the Gilliam-like sera. CONCLUSIONS/SIGNIFICANCE: Antigenic cartography worked well with scrub typhus indirect immunofluorescence titres. The data from humoral responses suggest that a Karp-like strain would provide broader antibody cross-reactivity than a Gilliam-like strain. Although previous exposure to O. tsutsugamushi could not be ruled out, scrub typhus patient serum antibody responses were characterised by strong homologous, but weak heterologous antibody titres, with little evidence for cross-reactivity by Gilliam-like sera, but a broader response from some Karp-like sera. This work highlights the importance of antigenic variation in O. tsutsugamushi diagnosis and determination of new serotypes.

Asante KP, Jones C, Sirima SB, Molyneux S. 2016. Clinical Trials Cannot Substitute for Health System Strengthening Initiatives or Specifically Designed Health Policy and Systems Research. Am J Bioeth, 16 (6), pp. 24-26. | Citations: 1 (Web of Science Lite) | Read more

Bassat Q, Tanner M, Guerin PJ, Stricker K, Hamed K. 2016. Combating poor-quality anti-malarial medicines: a call to action. Malar J, 15 (1), pp. 302. | Citations: 9 (Scopus) | Show Abstract | Read more

The circulation of poor-quality medicines continues to undermine the fight against many life-threatening diseases. Anti-malarial medicines appear to have been particularly compromised and present a major public health threat in malaria-endemic countries, negatively affecting individuals and their communities. Concerted collaborative efforts are required from global, regional and national organizations, involving the public and private sectors, to address the problem. While many initiatives are underway, a number of unmet needs deserve urgent and increased multisector attention. At the global level, there is a need for an international public health legal framework or treaty on poor-quality medicines, with statutes suitable for integration into national laws. In addition, increased international efforts are required to strengthen the governance of global supply chains and enhance cooperation between national medicine regulation authorities and law enforcement bodies. Increased investment is needed in innovative technologies that will enable healthcare teams to detect poor-quality medicines at all levels of the supply chain. At the regional level, a number of initiatives would be beneficial-key areas are standardization, simplification, and reciprocal recognition of registration processes and development of quality control capacity in regional centres of excellence that are better aligned with public health needs; improved surveillance methods and creation of a framework for compulsory and transparent reporting of poor-quality medicines; additional support for national medicine regulation authorities and other national partner authorities; and an increase in support for regional laboratories to boost their capabilities in detecting poor-quality medicines. It is vital that all stakeholders involved in efforts against poor-quality anti-malarial medicines extend and strengthen their actions in these critical areas and thus effectively support global health development and malaria elimination programmes.

van Wonderen KE, Geskus RB, van Aalderen WMC, Mohrs J, Bindels PJE, van der Mark LB, Ter Riet G. 2016. Stability and predictiveness of multiple trigger and episodic viral wheeze in preschoolers. Clin Exp Allergy, 46 (6), pp. 837-847. | Citations: 6 (Scopus) | Show Abstract | Read more

BACKGROUND: In 2008, the European Respiratory Society Task Force proposed the terms multiple-trigger wheeze (MTW) and episodic (viral) wheeze (EVW) for children with wheezing episodes. We determined MTW and EVW prevalence, their 24-month stability and predictiveness for asthma. METHODS: In total, 565 preschoolers (1-, 2- and 3-year-olds) in primary care with respiratory symptoms were followed until the age of 6 years when asthma was diagnosed. MTW status and EVW status were determined using questionnaire data collected at baseline and after one and 2 years. We distinguished 3 phenotypes and determined their 24-month stability, also accounting for treatment with inhaled corticosteroids (ICS). Logistic regression was used to analyse the phenotypes' associations with asthma. RESULTS: Two hundred and eighty-one children had complete information. MTW and EVW were stable in 10 of 281 (3.6%) and 24 of 281 (8.5%), respectively. The odds of developing asthma for children with stable MTW and stable EVW were 14.4 (1.7-119) and 3.6 (1.2-11.3) times greater than those for children free of wheeze (for at least 1 year). ICS was associated with increased stability of MTW and EVW. CONCLUSIONS: Stable multiple-trigger and stable episodic viral wheeze are relatively uncommon. However, 1- to 3-year-olds with stable MTW are at much increased risk of asthma.

Nisalak A, Clapham HE, Kalayanarooj S, Klungthong C, Thaisomboonsuk B, Fernandez S, Reiser J, Srikiatkhachorn A, Macareo LR, Lessler JT et al. 2016. Forty Years of Dengue Surveillance at a Tertiary Pediatric Hospital in Bangkok, Thailand, 1973-2012. Am J Trop Med Hyg, 94 (6), pp. 1342-1347. | Citations: 1 (Scopus) | Show Abstract | Read more

Long-term observational studies can provide valuable insights into overall dengue epidemiology. Here, we present analysis of dengue cases at a pediatric hospital in Bangkok, Thailand, during a 40-year period from 1973 to 2012. Data were analyzed from 25,715 hospitalized patients with laboratory-confirmed dengue virus (DENV) infection. Several long-term trends in dengue disease were identified including an increase in mean age of hospitalized cases from an average of 7-8 years, an increase after 1990 in the proportion of post-primary cases for DENV-1 and DENV-3, and a decrease in the proportion of dengue hemorrhagic fever and dengue shock syndrome cases in primary and post-primary cases over time. Exploratory mechanistic analysis of these observed trends considered changes in diagnostic methods, demography, force of infection, and Japanese encephalitis vaccination as possible explanations. Thailand is an important setting for studying DENV transmission as it has a "mature" dengue epidemiology with a strong surveillance system in place since the early 1970s. We characterized changes in dengue epidemiology over four decades, and possible impact of demographic and other changes in the human population. These results may inform other countries where similar changes in transmission and population demographics may now or may soon be occurring.

Bourke CD, Berkley JA, Prendergast AJ. 2016. Immune Dysfunction as a Cause one Consecuence of Malnutrition TRENDS IN IMMUNOLOGY, 37 (6), pp. 386-398. | Citations: 5 (Web of Science Lite) | Read more

Radin E, Ariana P, Broekel T, Tran TK. 2016. Analyzing demand-side efficiency in global health: an application to maternal care in Vietnam. Health Policy Plan, 31 (9), pp. 1281-1290. | Show Abstract | Read more

This article investigates demand-side efficiency in global health-or the efficiency with which health system users convert public health resources into health outcomes. We introduce and explain the concept of demand-side efficiency as well as quantitative methods to empirically estimate it. Using a robust nonparametric form of technical efficiency analysis, we estimate demand side efficiency and its social determinants. We pilot these methods looking at how efficiently pregnant women in Northern Vietnam convert public health resources into appropriate maternal care as defined by national policy. We find that women who live in non-mountainous geographies, who are formally employed, who are pregnant with a boy and who are ethnic minorities are all more likely to be efficient at achieving appropriate care. We find no significant association between wealth or education and efficiency. Our results suggest that, in the Vietnamese context, women who are the most likely to achieve appropriate maternal care, are not necessarily the most likely to do so efficiently. Women who live in non-mountainous geographies and who are formally employed are both more likely to achieve appropriate care and to do so efficiently. Yet ethnic minority women, who do not systematically achieve better care, are more likely to be efficient or to achieve better care when compared with those with the same endowment of public health resources. On the methodological level, the pilot highlights that this approach can provide useful information for policy by identifying which groups of people are more and less likely to be efficient. By understanding which groups are more likely to be efficient-and in turn how and why-it may be possible to devise policies to promote the drivers of, or conversely address the constraints to, optimizing demand-side efficiency.

Molyneux S, Sariola S, Allman D, Dijkstra M, Gichuru E, Graham S, Kamuya D, Gakii G, Kayemba B, Kombo B et al. 2016. Public/community engagement in health research with men who have sex with men in sub-Saharan Africa: challenges and opportunities. Health Res Policy Syst, 14 (1), pp. 40. | Citations: 1 (Scopus) | Show Abstract | Read more

BACKGROUND: Community engagement, incorporating elements of the broader concepts of public and stakeholder engagement, is increasingly promoted globally, including for health research conducted in developing countries. In sub-Saharan Africa, community engagement needs and challenges are arguably intensified for studies involving gay, bisexual and other men who have sex with men, where male same-sex sexual interactions are often highly stigmatised and even illegal. This paper contextualises, describes and interprets the discussions and outcomes of an international meeting held at the Kenya Medical Research Institute-Wellcome Trust in Kilifi, Kenya, in November 2013, to critically examine the experiences with community engagement for studies involving men who have sex with men. DISCUSSION: We discuss the ethically charged nature of the language used for men who have sex with men, and of working with 'representatives' of these communities, as well as the complementarity and tensions between a broadly public health approach to community engagement, and a more rights based approach. We highlight the importance of researchers carefully considering which communities to engage with, and the goals, activities, and indicators of success and potential challenges for each. We suggest that, given the unintended harms that can emerge from community engagement (including through labelling, breaches in confidentiality, increased visibility and stigma, and threats to safety), representatives of same-sex populations should be consulted from the earliest possible stage, and that engagement activities should be continuously revised in response to unfolding realities. Engagement should also include less vocal and visible men who have sex with men, and members of other communities with influence on the research, and on research participants and their families and friends. Broader ethics support, advice and research into studies involving men who have sex with men is needed to ensure that ethical challenges - including but not limited to those related to community engagement - are identified and addressed. Underlying challenges and dilemmas linked to stigma and discrimination of men who have sex with men in Africa raise special responsibilities for researchers. Community engagement is an important way of identifying responses to these challenges and responsibilities but itself presents important ethical challenges.

Phommasone K, Adhikari B, Henriques G, Pongvongsa T, Phongmany P, von Seidlein L, White NJ, Day NPJ, M Dondorp A, Newton PN et al. 2016. Asymptomatic Plasmodium infections in 18 villages of southern Savannakhet Province, Lao PDR (Laos). Malar J, 15 (1), pp. 296. | Citations: 9 (Scopus) | Show Abstract | Read more

BACKGROUND: A large fraction of Plasmodium infections do not cause clinical signs and symptoms of disease and persist at densities in blood that are not detectable by microscopy or rapid diagnostic tests. These infections may be critical as a transmission reservoir in areas of low malaria endemicity. Understanding the epidemiology of these infections would be helpful for malaria elimination. METHODS: A cross-sectional survey was conducted in Thapangthong and Nong Districts of Savannakhet Province, Lao PDR, to determine the prevalence of parasitaemia. A total of 888 blood samples were collected from afebrile volunteers aged ≥15 years in 18 villages during March and July 2015. Plasmodium infections were diagnosed by rapid diagnostic tests (RDT) and high volume, ultra-sensitive quantitative polymerase chain reaction (uPCR). RESULTS: uPCR detected Plasmodium infections in 175 of 888 samples (20 %). The species distribution was Plasmodium falciparum 3.6 % (32/888), Plasmodium vivax 11.1 % (99/888), mixed infections with P. falciparum and P. vivax 1.6 % (14/888) and Plasmodium of undetermined species 3.4 % (30/888). RDT identified only 2 % (18/888) positive cases. Using uPCR as reference, the sensitivity and specificity of RDTs were 28 and 100 %, respectively, in detecting P. falciparum infections, and 3 and 99 % in detecting asymptomatic P. vivax infections. The K13 kelch propeller domain C580Y mutation, associated with reduced susceptibility to artemisinin derivatives, was found in 75 % (12/18) of P. falciparum isolates from Thapangthong and in 7 % (2/28) from Nong (p < 0.001). In a multivariate analysis, males were more likely to have P. vivax infections [adjusted odds ratio (aOR) 4.76 (95 % CI 2.84-8.00)] while older villagers were at lower risk for parasitaemia [aOR for increasing age 0.98 (95 % CI 0.96-0.99)]. CONCLUSION: There is a high prevalence of asymptomatic Plasmodium infections in southern Savannakhet. Artemisinin-resistant P. falciparum strains form an increasing proportion of the parasite population in Thapangthong District and are already present in the more remote Nong District. This worrying trend has wider implications for Laos and could reverse the gains achieved by the successful control of malaria in Laos and the Greater Mekong Sub-region (GMS). Rapid elimination of P. falciparum has to be a top priority in Laos as well as in the wider GMS.

Kenyan Bacteraemia Study Group, Wellcome Trust Case Control Consortium 2 (WTCCC2), Rautanen A, Pirinen M, Mills TC, Rockett KA, Strange A, Ndungu AW, Naranbhai V, Gilchrist JJ et al. 2016. Polymorphism in a lincRNA Associates with a Doubled Risk of Pneumococcal Bacteremia in Kenyan Children. Am J Hum Genet, 98 (6), pp. 1092-1100. | Citations: 3 (Web of Science Lite) | Show Abstract | Read more

Bacteremia (bacterial bloodstream infection) is a major cause of illness and death in sub-Saharan Africa but little is known about the role of human genetics in susceptibility. We conducted a genome-wide association study of bacteremia susceptibility in more than 5,000 Kenyan children as part of the Wellcome Trust Case Control Consortium 2 (WTCCC2). Both the blood-culture-proven bacteremia case subjects and healthy infants as controls were recruited from Kilifi, on the east coast of Kenya. Streptococcus pneumoniae is the most common cause of bacteremia in Kilifi and was thus the focus of this study. We identified an association between polymorphisms in a long intergenic non-coding RNA (lincRNA) gene (AC011288.2) and pneumococcal bacteremia and replicated the results in the same population (p combined = 1.69 × 10(-9); OR = 2.47, 95% CI = 1.84-3.31). The susceptibility allele is African specific, derived rather than ancestral, and occurs at low frequency (2.7% in control subjects and 6.4% in case subjects). Our further studies showed AC011288.2 expression only in neutrophils, a cell type that is known to play a major role in pneumococcal clearance. Identification of this novel association will further focus research on the role of lincRNAs in human infectious disease.

Baragaña B, Hallyburton I, Lee MCS, Norcross NR, Grimaldi R, Otto TD, Proto WR, Blagborough AM, Meister S, Wirjanata G et al. 2016. Corrigendum: A novel multiple-stage antimalarial agent that inhibits protein synthesis. Nature, 537 (7618), pp. 122. | Read more

WWARN Gametocyte Study Group. 2016. Gametocyte carriage in uncomplicated Plasmodium falciparum malaria following treatment with artemisinin combination therapy: a systematic review and meta-analysis of individual patient data. BMC Med, 14 (1), pp. 79. | Citations: 17 (Scopus) | Show Abstract | Read more

BACKGROUND: Gametocytes are responsible for transmission of malaria from human to mosquito. Artemisinin combination therapy (ACT) reduces post-treatment gametocyte carriage, dependent upon host, parasite and pharmacodynamic factors. The gametocytocidal properties of antimalarial drugs are important for malaria elimination efforts. An individual patient clinical data meta-analysis was undertaken to identify the determinants of gametocyte carriage and the comparative effects of four ACTs: artemether-lumefantrine (AL), artesunate/amodiaquine (AS-AQ), artesunate/mefloquine (AS-MQ), and dihydroartemisinin-piperaquine (DP). METHODS: Factors associated with gametocytaemia prior to, and following, ACT treatment were identified in multivariable logistic or Cox regression analysis with random effects. All relevant studies were identified through a systematic review of PubMed. Risk of bias was evaluated based on study design, methodology, and missing data. RESULTS: The systematic review identified 169 published and 9 unpublished studies, 126 of which were shared with the WorldWide Antimalarial Resistance Network (WWARN) and 121 trials including 48,840 patients were included in the analysis. Prevalence of gametocytaemia by microscopy at enrolment was 12.1 % (5887/48,589), and increased with decreasing age, decreasing asexual parasite density and decreasing haemoglobin concentration, and was higher in patients without fever at presentation. After ACT treatment, gametocytaemia appeared in 1.9 % (95 % CI, 1.7-2.1) of patients. The appearance of gametocytaemia was lowest after AS-MQ and AL and significantly higher after DP (adjusted hazard ratio (AHR), 2.03; 95 % CI, 1.24-3.12; P = 0.005 compared to AL) and AS-AQ fixed dose combination (FDC) (AHR, 4.01; 95 % CI, 2.40-6.72; P < 0.001 compared to AL). Among individuals who had gametocytaemia before treatment, gametocytaemia clearance was significantly faster with AS-MQ (AHR, 1.26; 95 % CI, 1.00-1.60; P = 0.054) and slower with DP (AHR, 0.74; 95 % CI, 0.63-0.88; P = 0.001) compared to AL. Both recrudescent (adjusted odds ratio (AOR), 9.05; 95 % CI, 3.74-21.90; P < 0.001) and new (AOR, 3.03; 95 % CI, 1.66-5.54; P < 0.001) infections with asexual-stage parasites were strongly associated with development of gametocytaemia after day 7. CONCLUSIONS: AS-MQ and AL are more effective than DP and AS-AQ FDC in preventing gametocytaemia shortly after treatment, suggesting that the non-artemisinin partner drug or the timing of artemisinin dosing are important determinants of post-treatment gametocyte dynamics.

Seale AC, Koech AC, Sheppard AE, Barsosio HC, Langat J, Anyango E, Mwakio S, Mwarumba S, Morpeth SC, Anampiu K et al. 2016. Maternal colonisation with Streptococcus agalactiae, and associated stillbirth and neonatal disease in coastal Kenya. Nat Microbiol, 1 (7), pp. 16067-16067. | Citations: 12 (Web of Science Lite) | Show Abstract | Read more

Streptococcus agalactiae (Group B Streptococcus, GBS) causes neonatal disease and stillbirth, but its burden in sub-Saharan Africa is uncertain. We assessed maternal recto-vaginal GBS colonisation (7967 women), stillbirth and neonatal disease. Whole genome sequencing was used to determine serotypes, sequence types (ST), and phylogeny. We found low maternal GBS colonisation prevalence (934/7967, 12%), but comparatively high incidence of GBS-associated stillbirth and early onset neonatal disease (EOD) in hospital (0.91(0.25-2.3)/1000 births; 0.76(0.25-1.77)/1000 live-births respectively). However, using a population denominator, EOD incidence was considerably reduced (0.13(0.07-0.21)/1000 live-births). Treated cases of EOD had very high case fatality (17/36, 47%), especially within 24 hours of birth, making under-ascertainment of community-born cases highly likely, both here and in similar facility-based studies. Maternal GBS colonisation was less common in women with low socio-economic status, HIV infection and undernutrition, but when GBS-colonised, they were more likely colonised by the most virulent clone, CC17. CC17 accounted for 267/915(29%) of maternal colonising (265/267(99%) serotype III, 2/267(0.7%) serotype IV), and 51/73(70%) of neonatal disease cases (all serotype III). Trivalent (Ia/II/III) and pentavalent (Ia/Ib/II/III/V) vaccines would cover 71/73(97%) and 72/73(99%) of disease-causing serotypes respectively. Serotype IV should be considered for inclusion, with evidence of capsular switching in CC17 strains.

Blohmke CJ, Darton TC, Jones C, Suarez NM, Waddington CS, Angus B, Zhou L, Hill J, Clare S, Kane L et al. 2016. Interferon-driven alterations of the host's amino acid metabolism in the pathogenesis of typhoid fever. J Exp Med, 213 (6), pp. 1061-1077. | Citations: 9 (Web of Science Lite) | Show Abstract | Read more

Enteric fever, caused by Salmonella enterica serovar Typhi, is an important public health problem in resource-limited settings and, despite decades of research, human responses to the infection are poorly understood. In 41 healthy adults experimentally infected with wild-type S. Typhi, we detected significant cytokine responses within 12 h of bacterial ingestion. These early responses did not correlate with subsequent clinical disease outcomes and likely indicate initial host-pathogen interactions in the gut mucosa. In participants developing enteric fever after oral infection, marked transcriptional and cytokine responses during acute disease reflected dominant type I/II interferon signatures, which were significantly associated with bacteremia. Using a murine and macrophage infection model, we validated the pivotal role of this response in the expression of proteins of the host tryptophan metabolism during Salmonella infection. Corresponding alterations in tryptophan catabolites with immunomodulatory properties in serum of participants with typhoid fever confirmed the activity of this pathway, and implicate a central role of host tryptophan metabolism in the pathogenesis of typhoid fever.

Weehuizen TAF, Lankelma JM, De Jong HK, De Boer OJ, Roelofs JJTH, Day NP, Gram H, De Vos AF, Wiersinga WJ. 2016. Therapeutic Administration of a Monoclonal Anti-Il-1β Antibody Protects Against Experimental Melioidosis. Shock, 46 (5), pp. 566-574. | Citations: 2 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Melioidosis, caused by the gram-negative bacterium Burkholderia pseudomallei, is a common cause of community-acquired sepsis in Southeast Asia and Northern Australia. The NLRP3 inflammasome and its downstream product interleukin-1 beta (IL-1β) have been proposed to play crucial roles in melioidosis. In this study, we characterized the role of IL-1β more closely and we assessed its therapeutic potential. METHODS: mRNA expression of inflammasome components was determined in isolated leukocytes of 32 healthy controls and 34 patients with sepsis caused by B pseudomallei.Wild-type (WT), NLRP3-deficient (Nlrp3), and Asc mice were infected with B pseudomallei. In additional experiments, infected WT mice were treated with an anti-IL-1β antibody. After 24, 48, and 72 hours (h) mice were sacrificed and organs were harvested. Furthermore, survival studies were performed. RESULTS: Patients with melioidosis exhibited lower mRNA levels of caspase-1, NLRP3, and ASC. Bacterial dissemination and organ damage were increased in B pseudomallei-infected Nlrp3 and Asc mice, together with a reduced pulmonary cell influx. Anti-IL-1β treatment of B pseudomallei challenged mice resulted in strongly reduced bacterial counts, organ damage, and pulmonary granulocyte influx together with reduced mortality. Postponement of anti-IL-1β treatment for 24 h postinfection still protected mice during melioidosis. CONCLUSION: Expression of caspase-1, NLRP3, and ASC is altered in melioidosis patients. In mice, both NLRP3 and ASC contribute to the host defense against melioidosis. Anti-IL-1β treatment protects mice against B pseudomallei infection and might be a novel treatment strategy in melioidosis.

Clapham HE, Quyen TH, Kien DTH, Dorigatti I, Simmons CP, Ferguson NM. 2016. Modelling Virus and Antibody Dynamics during Dengue Virus Infection Suggests a Role for Antibody in Virus Clearance. PLoS Comput Biol, 12 (5), pp. e1004951. | Citations: 3 (Web of Science Lite) | Show Abstract | Read more

Dengue is an infection of increasing global importance, yet uncertainty remains regarding critical aspects of its virology, immunology and epidemiology. One unanswered question is how infection is controlled and cleared during a dengue infection. Antibody is thought to play a role, but little past work has examined the kinetics of both virus and antibody during natural infections. We present data on multiple virus and antibody titres measurements recorded sequentially during infection from 53 Vietnamese dengue patients. We fit mechanistic mathematical models of the dynamics of viral replication and the host immune response to these data. These models fit the data well. The model with antibody removing virus fits the data best, but with a role suggested for ADCC or other infected cell clearance mechanisms. Our analysis therefore shows that the observed viral and antibody kinetics are consistent with antibody playing a key role in controlling viral replication. This work gives quantitative insight into the relationship between antibody levels and the efficiency of viral clearance. It will inform the future development of mechanistic models of how vaccines and antivirals might modify the course of natural dengue infection.

Sinha A, Russell LB, Tomczyk S, Verani JR, Schrag SJ, Berkley JA, Mohammed M, Sigauque B, Kim S-Y, GBS Vaccine Cost-Effectiveness Analysis in Sub-Saharan Africa Working Group. 2016. Disease Burden of Group B Streptococcus Among Infants in Sub-Saharan Africa: A Systematic Literature Review and Meta-analysis. Pediatr Infect Dis J, 35 (9), pp. 933-942. | Citations: 5 (Scopus) | Show Abstract | Read more

BACKGROUND: Group B streptococcus (GBS) is a leading neonatal sepsis pathogen globally. Investment in GBS disease prevention, such as maternal vaccination, requires evidence of disease burden, particularly in high infant mortality regions like sub-Saharan Africa. We aimed to provide such evidence by conducting a systematic literature review and meta-analysis to estimate maternal colonization proportion, GBS disease incidence and GBS serotype distribution. METHODS: MEDLINE, MEDLINE in process and Cochrane Library were searched for studies published during 1990-2014, pertaining to sub-Saharan Africa. Eligible studies were used to estimate the proportion of pregnant women colonized with GBS, early-onset GBS disease incidence, late-onset GBS disease incidence and respective serotype distributions. Random effects meta-analysis was conducted to estimate weighted means and confidence intervals (CIs). RESULTS: We identified 17 studies of colonization, 9 of disease incidence, and 6 of serotype distribution meeting inclusion criteria. 21.8% (95% CI: 18.3, 25.5) of expectant women were colonized with GBS. The incidence of early-onset GBS disease was 1.3 per 1000 births (95% CI: 0.81, 1.9), that of late-onset GBS disease 0.73 per 1000 births (95% CI: 0.48, 1.0). The most common disease-causing serotype was 3, followed by 1a. Serotypes 1b, 2 and 5 were next most common in frequency. CONCLUSION: Despite methodological factors leading to underestimation, GBS disease incidence appears high in sub-Saharan Africa. A small number of GBS serotypes cause almost all disease. GBS disease burden in sub-Saharan Africa suggests that safe, effective and affordable GBS disease prevention is needed.

Van Cuong N, Nhung NT, Nghia NH, Mai Hoa NT, Trung NV, Thwaites G, Carrique-Mas J. 2016. Antimicrobial Consumption in Medicated Feeds in Vietnamese Pig and Poultry Production. Ecohealth, 13 (3), pp. 490-498. | Citations: 7 (Scopus) | Show Abstract | Read more

Antimicrobials are extensively used as growth promoters in animal feeds worldwide, but reliable estimates are lacking. We conducted an internet-based survey of commercial chicken and pig feed products officially approved for sale in Vietnam over the period March-June 2015. Information on the antimicrobial contents in feed products, alongside animal production data, was used to estimate in-feed antimicrobial consumption to produce one kilogram of live animal (chicken, pig), as well as to estimate country-wide antimicrobial consumption through animal feeds. A total of 1462 commercial feed formulations were examined. The survey-adjusted estimated antimicrobial contents were 25.7 and 62.3 mg/kg in chicken and pig feeds, respectively. Overall, it was estimated that 77.4 mg [95% CI 48.1-106.8] and 286.6 mg [95% CI 191.6-418.3] of in-feed antimicrobials were used to raise 1 kg of live chicken and pig, respectively. Bacitracin (15.5% feeds), chlortetracycline (11.4%), and enramycin (10.8%) were the most common antimicrobials present in chicken feed formulations, whereas bacitracin (24.8%), chlortetracycline (23.9%), and florfenicol (17.4%) were the most common in pig feed formulations. Overall, 57% of the total quantitative usage consisted of antimicrobials regarded by WHO of importance for human medicine, including amoxicillin, colistin, tetracyclines, neomycin, lincomycin, and bacitracin. These figures confirm a very high magnitude of in-feed consumption of antimicrobials, especially in pig production. Results from this study should encourage further monitoring of antimicrobials used in animal production, and foster discussion about existing policies on inclusion of antimicrobials in animal feed rations.

Chan J-A, Howell KB, Langer C, Maier AG, Hasang W, Rogerson SJ, Petter M, Chesson J, Stanisic DI, Duffy MF et al. 2016. A single point in protein trafficking by Plasmodium falciparum determines the expression of major antigens on the surface of infected erythrocytes targeted by human antibodies. Cell Mol Life Sci, 73 (21), pp. 4141-4158. | Citations: 8 (Scopus) | Show Abstract | Read more

Antibodies to blood-stage antigens of Plasmodium falciparum play a pivotal role in human immunity to malaria. During parasite development, multiple proteins are trafficked from the intracellular parasite to the surface of P. falciparum-infected erythrocytes (IEs). However, the relative importance of different proteins as targets of acquired antibodies, and key pathways involved in trafficking major antigens remain to be clearly defined. We quantified antibodies to surface antigens among children, adults, and pregnant women from different malaria-exposed regions. We quantified the importance of antigens as antibody targets using genetically engineered P. falciparum with modified surface antigen expression. Genetic deletion of the trafficking protein skeleton-binding protein-1 (SBP1), which is involved in trafficking the surface antigen PfEMP1, led to a dramatic reduction in antibody recognition of IEs and the ability of human antibodies to promote opsonic phagocytosis of IEs, a key mechanism of parasite clearance. The great majority of antibody epitopes on the IE surface were SBP1-dependent. This was demonstrated using parasite isolates with different genetic or phenotypic backgrounds, and among antibodies from children, adults, and pregnant women in different populations. Comparisons of antibody reactivity to parasite isolates with SBP1 deletion or inhibited PfEMP1 expression suggest that PfEMP1 is the dominant target of acquired human antibodies, and that other P. falciparum IE surface proteins are minor targets. These results establish SBP1 as part of a critical pathway for the trafficking of major surface antigens targeted by human immunity, and have key implications for vaccine development, and quantifying immunity in populations.

Newton PN, Caillet C, Guerin PJ. 2016. A link between poor quality antimalarials and malaria drug resistance? Expert Rev Anti Infect Ther, 14 (6), pp. 531-533. | Citations: 4 (Scopus) | Read more

Lai S, Qin Y, Cowling BJ, Ren X, Wardrop NA, Gilbert M, Tsang TK, Wu P, Feng L, Jiang H et al. 2016. Global epidemiology of avian influenza A H5N1 virus infection in humans, 1997-2015: a systematic review of individual case data. Lancet Infect Dis, 16 (7), pp. e108-e118. | Citations: 27 (Scopus) | Show Abstract | Read more

Avian influenza A H5N1 viruses have caused many, typically severe, human infections since the first human case was reported in 1997. However, no comprehensive epidemiological analysis of global human cases of H5N1 from 1997 to 2015 exists. Moreover, few studies have examined in detail the changing epidemiology of human H5N1 cases in Egypt, especially given the outbreaks since November, 2014, which have the highest number of cases ever reported worldwide in a similar period. Data on individual patients were collated from different sources using a systematic approach to describe the global epidemiology of 907 human H5N1 cases between May, 1997, and April, 2015. The number of affected countries rose between 2003 and 2008, with expansion from east and southeast Asia, then to west Asia and Africa. Most cases (67·2%) occurred from December to March, and the overall case-fatality risk was 483 (53·5%) of 903 cases which varied across geographical regions. Although the incidence in Egypt has increased dramatically since November, 2014, compared with the cases beforehand, there were no significant differences in the fatality risk, history of exposure to poultry, history of patient contact, and time from onset to hospital admission in the recent cases.

Wangchuk S, Drukpa T, Penjor K, Peldon T, Dorjey Y, Dorji K, Chhetri V, Trimarsanto H, To S, Murphy A et al. 2016. Where chloroquine still works: the genetic make-up and susceptibility of Plasmodium vivax to chloroquine plus primaquine in Bhutan. Malar J, 15 (1), pp. 277. | Citations: 6 (Scopus) | Show Abstract | Read more

BACKGROUND: Bhutan has made substantial progress in reducing malaria incidence. The national guidelines recommend chloroquine (CQ) and primaquine (PQ) for radical cure of uncomplicated Plasmodium vivax, but the local efficacy has not been assessed. The impact of cases imported from India on the genetic make-up of the local vivax populations is currently unknown. METHODS: Patients over 4 years of age with uncomplicated P. vivax mono-infection were enrolled into a clinical efficacy study and molecular survey. Study participants received a standard dose of CQ (25 mg/kg over 3 days) followed by weekly review until day 28. On day 28 a 14-day regimen of PQ (0.25 mg/kg/day) was commenced under direct observation. After day 42, patients were followed up monthly for a year. The primary and secondary endpoints were risk of treatment failure at day 28 and at 1 year. Parasite genotyping was undertaken at nine tandem repeat markers, and standard population genetic metrics were applied to examine population diversity and structure in infections thought to be acquired inside or outside of Bhutan. RESULTS: A total of 24 patients were enrolled in the clinical study between April 2013 and October 2015. Eight patients (33.3 %) were lost to follow-up in the first 6 months and another eight patients lost between 6 and 12 months. No (0/24) treatment failures occurred by day 28 and no (0/8) parasitaemia was detected following PQ treatment. Some 95.8 % (23/24) of patients were aparasitaemic by day 2. There were no haemolytic or serious events. Genotyping was undertaken on parasites from 12 autochthonous cases and 16 suspected imported cases. Diversity was high (H E 0.87 and 0.90) in both populations. There was no notable differentiation between the autochthonous and imported populations. CONCLUSIONS: CQ and PQ remains effective for radical cure of P. vivax in Bhutan. The genetic analyses indicate that imported infections are sustaining the local vivax population, with concomitant risk of introducing drug-resistant strains.

Merson L, Gaye O, Guerin PJ. 2016. Avoiding Data Dumpsters--Toward Equitable and Useful Data Sharing. N Engl J Med, 374 (25), pp. 2414-2415. | Citations: 28 (Scopus) | Read more

Nguyen NM, Whitehorn JS, Luong Thi Hue T, Nguyen Thanh T, Mai Xuan T, Vo Xuan H, Nguyen Thi Cam H, Nguyen Thi Hong L, Nguyen HL, Dong Thi Hoai T et al. 2016. Physicians, Primary Caregivers and Topical Repellent: All Under-Utilised Resources in Stopping Dengue Virus Transmission in Affected Households. PLoS Negl Trop Dis, 10 (5), pp. e0004667. | Citations: 2 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Primary health care facilities frequently manage dengue cases on an ambulatory basis for the duration of the patient's illness. There is a great opportunity for specific messaging, aimed to reduce dengue virus (DENV) transmission in and around the home, to be directly targeted toward this high-risk ambulatory patient group, as part of an integrated approach to dengue management. The extent however, to which physicians understand, and can themselves effectively communicate strategies to stop focal DENV transmission around an ambulatory dengue case is unknown; the matter of patient comprehension and recollection then ensues. In addition, the effectiveness of N,N-diethyl-3-methylbenzamide (DEET)-based insect repellent in protecting dengue patients from Aedes aegypti mosquitoes' bites has not been investigated. METHODOLOGY: A knowledge, attitude and practice (KAP) survey, focusing on the mechanisms of DENV transmission and prevention, was performed using semi-structured questionnaires. This survey was targeted towards the patients and family members providing supportive care, and physicians routinely involved in dengue patient management in Southern Vietnam. An additional clinical observational study was conducted to measure the efficacy of a widely-used 13% DEET-based insect repellent to repel Ae. aegypti mosquitoes from the forearms of dengue cases and matched healthy controls. PRINCIPAL FINDINGS: Among both the physician (n = 50) and patient (n = 49) groups there were several respondents lacking a coherent understanding of DENV transmission, leading to some inappropriate attitudes and inadequate acute preventive practices in the household. The application of insect repellent to protect patients and their relatives from mosquito bites was frequently recommended by majority of physicians (78%) participating in the survey. Nevertheless, our tested topical application of 13% DEET conferred only ~1hr median protection time from Ae. aegypti landing. This is notably shorter than that advertised on the manufacturer's label. No differences in landing time between febrile dengue cases or matched healthy controls (n = 19 experiments) were observed. CONCLUSION/SIGNIFICANCE: Our study identifies missed opportunities for primary care physicians to improve public health through communication of strategies that could prevent focal dengue transmission in and around a case household. We advocate better access to more efficient communication methods for physicians and auxilliary health workers, supporting to educate those at high risk of DENV transmission. Our empirical testing of a widely-available 13% DEET-based repellent was limited in its protective efficacy against Ae. aegypti mosquito bites, and therefore DENV transmission, suggesting more frequent application is necessary to be beneficial.

Angood C, Khara T, Dolan C, Berkley JA, WaSt Technical Interest Group. 2016. Research Priorities on the Relationship between Wasting and Stunting. PLoS One, 11 (5), pp. e0153221. | Citations: 4 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Wasting and stunting are global public health problems that frequently co-exist. However, they are usually separated in terms of policy, guidance, programming and financing. Though both wasting and stunting are manifestations of undernutrition caused by disease and poor diet, there are critical gaps in our understanding of the physiological relationship between them, and how interventions for one may affect the other. The aim of this exercise was to establish research priorities in the relationships between wasting and stunting to guide future research investments. METHODS AND FINDINGS: We used the CHNRI (Child Health and Nutrition Research Initiative) methodology for setting research priorities in health. We utilised a group of experts in nutrition, growth and child health to prioritise 30 research questions against three criteria (answerability, usefulness and impact) using an online survey. Eighteen of 25 (72%) experts took part and prioritised research directly related to programming, particularly at the public health level. The highest-rated questions were: "Can interventions outside of the 1000 days, e.g. pre-school, school age and adolescence, lead to catch-up in height and in other developmental markers?"; "What timely interventions work to mitigate seasonal peaks in both wasting and stunting?"; and "What is the optimal formulation of ready-to-use foods to promote optimal ponderal growth and also support linear growth during and after recovery from severe acute malnutrition?" There was a high level of agreement between experts, particularly for the highest ranking questions. CONCLUSIONS: Increased commitment to rigorous evaluations of treatment and prevention interventions at the public health level, addressing questions of the timing of intervention, and the extent to which impacts for both wasting and stunting can be achieved, is needed to inform global efforts to tackle undernutrition and its consequences.

Vongsouvath M, Phommasone K, Sengvilaipaseuth O, Kosoltanapiwat N, Chantratita N, Blacksell SD, Lee SJ, de Lamballerie X, Mayxay M, Keomany S et al. 2016. Using Rapid Diagnostic Tests as a Source of Viral RNA for Dengue Serotyping by RT-PCR - A Novel Epidemiological Tool. PLoS Negl Trop Dis, 10 (5), pp. e0004704. | Show Abstract | Read more

BACKGROUND: Dengue virus infection causes major public health problems in tropical and subtropical areas. In many endemic areas, including the Lao PDR, inadequate access to laboratory facilities is a major obstacle to surveillance and study of dengue epidemiology. Filter paper is widely used for blood collection for subsequent laboratory testing for antibody and nucleic acid detection. For the first time, we demonstrate that dengue viral RNA can be extracted from dengue rapid diagnostic tests (RDT) and then submitted to real-time RT-PCR for serotyping. METHODOLOGY/PRINCIPAL FINDINGS: We evaluated the Standard Diagnostics (SD) Bioline Dengue Duo RDT, a commonly used test in dengue endemic areas. First, using the QIAamp RNA kit, dengue RNA was purified from the sample pad of the NS1 RDT loaded with virus isolates of the four serotypes, then quantified by RT-PCR. We observed greater recovery of virus, with a mean of 27 times more RNA recovered from RDT, than from filter paper. Second, we evaluated dengue NS1 RDTs from patients at Mahosot Hospital, Vientiane, (99 patients) and from rural Salavan Provincial Hospital (362 patients). There was good agreement between dengue RT-PCR from NS1 RDT with RT-PCR performed on RNA extracted from patient sera, either using RDT loaded with blood (82.8% and 91.4%, in Vientiane and Salavan, respectively) or serum (91.9% and 93.9%). There was 100% concordance between RDT and serum RT-PCR of infecting dengue serotype. CONCLUSIONS/SIGNIFICANCE: Therefore, the collection of NS1 positive RDTs, which do not require cold storage, may be a novel approach for dengue serotyping by RT-PCR and offers promising prospects for the collection of epidemiological data from previously inaccessible tropical areas to aid surveillance and public health interventions.

Ochola-Oyier LI, Okombo J, Wagatua N, Ochieng J, Tetteh KK, Fegan G, Bejon P, Marsh K. 2016. Comparison of allele frequencies of Plasmodium falciparum merozoite antigens in malaria infections sampled in different years in a Kenyan population. Malar J, 15 (1), pp. 261. | Show Abstract | Read more

BACKGROUND: Plasmodium falciparum merozoite antigens elicit antibody responses in malaria-endemic populations, some of which are clinically protective, which is one of the reasons why merozoite antigens are the focus of malaria vaccine development efforts. Polymorphisms in several merozoite antigen-encoding genes are thought to arise as a result of selection by the human immune system. METHODS: The allele frequency distribution of 15 merozoite antigens over a two-year period, 2007 and 2008, was examined in parasites obtained from children with uncomplicated malaria. In the same population, allele frequency changes pre- and post-anti-malarial treatment were also examined. Any gene which showed a significant shift in allele frequencies was also assessed longitudinally in asymptomatic and complicated malaria infections. RESULTS: Fluctuating allele frequencies were identified in codons 147 and 148 of reticulocyte-binding homologue (Rh) 5, with a shift from HD to YH haplotypes over the two-year period in uncomplicated malaria infections. However, in both the asymptomatic and complicated malaria infections YH was the dominant and stable haplotype over the two-year and ten-year periods, respectively. A logistic regression analysis of all three malaria infection populations between 2007 and 2009 revealed, that the chance of being infected with the HD haplotype decreased with time from 2007 to 2009 and increased in the uncomplicated and asymptomatic infections. CONCLUSION: Rh5 codons 147 and 148 showed heterogeneity at both an individual and population level and may be under some degree of immune selection.

Duffy MF, Noviyanti R, Tsuboi T, Feng Z-P, Trianty L, Sebayang BF, Takashima E, Sumardy F, Lampah DA, Turner L et al. 2016. Differences in PfEMP1s recognized by antibodies from patients with uncomplicated or severe malaria. Malar J, 15 (1), pp. 258. | Show Abstract | Read more

BACKGROUND: Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) variants are encoded by var genes and mediate pathogenic cytoadhesion and antigenic variation in malaria. PfEMP1s can be broadly divided into three principal groups (A, B and C) and they contain conserved arrangements of functional domains called domain cassettes. Despite their tremendous diversity there is compelling evidence that a restricted subset of PfEMP1s is expressed in severe disease. In this study antibodies from patients with severe and uncomplicated malaria were compared for differences in reactivity with a range of PfEMP1s to determine whether antibodies to particular PfEMP1 domains were associated with severe or uncomplicated malaria. METHODS: Parts of expressed var genes in a severe malaria patient were identified by RNAseq and several of these partial PfEMP1 domains were expressed together with others from laboratory isolates. Antibodies from Papuan patients to these parts of multiple PfEMP1 proteins were measured. RESULTS: Patients with uncomplicated malaria were more likely to have antibodies that recognized PfEMP1 of Group C type and recognized a broader repertoire of group A and B PfEMP1s than patients with severe malaria. CONCLUSION: These data suggest that exposure to a broad range of group A and B PfEMP1s is associated with protection from severe disease in Papua, Indonesia.

Bourke CD, Berkley JA, Prendergast AJ. 2016. Immune Dysfunction as a Cause and Consequence of Malnutrition. Trends Immunol, 37 (6), pp. 386-398. | Citations: 8 (Scopus) | Show Abstract | Read more

Malnutrition, which encompasses under- and overnutrition, is responsible for an enormous morbidity and mortality burden globally. Malnutrition results from disordered nutrient assimilation but is also characterized by recurrent infections and chronic inflammation, implying an underlying immune defect. Defects emerge before birth via modifications in the immunoepigenome of malnourished parents, and these may contribute to intergenerational cycles of malnutrition. This review summarizes key recent studies from experimental animals, in vitro models, and human cohorts, and proposes that immune dysfunction is both a cause and a consequence of malnutrition. Focusing on childhood undernutrition, we highlight gaps in current understanding of immune dysfunction in malnutrition, with a view to therapeutically targeting immune pathways as a novel means to reduce morbidity and mortality.

Govindasamy G, Barber BE, Ghani SA, William T, Grigg MJ, Borooah S, Dhillon B, Dondorp AM, Yeo TW, Anstey NM, Maude RJ. 2016. Retinal Changes in Uncomplicated and Severe Plasmodium knowlesi Malaria. J Infect Dis, 213 (9), pp. 1476-1482. | Citations: 1 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Plasmodium knowlesi causes severe malaria, but its pathogenesis is poorly understood. Retinal changes provide insights into falciparum malaria pathogenesis but have not been studied in knowlesi malaria. METHODS: An observational study was conducted in Malaysian adults hospitalized with severe (n = 20) and nonsevere (n = 24) knowlesi malaria using indirect ophthalmoscopy (n = 44) and fundus photography (n = 29). RESULTS: The patients' median age was 44 years (range, 18-74 years). No coma or deaths occurred. Photography detected retinal changes in 11 of 12 patients (92%) with severe and 14 of 17 (82%) with nonsevere knowlesi malaria. Nonspecific retinal whitening occurred in 3 (35%) and 5 (29%) patients with severe and nonsevere disease, respectively; hemorrhages in 2 (17%) and 3 (18%); loss of retinal pigment epithelium in 1 (8%) and 4 (24%); and drusen in 9 (71%) and 12 (75%). All changes were mild, with no significant differences between severe and nonsevere disease. Patients with retinal hemorrhages had lower platelet counts than those without (median, 22 vs 43 × 10(9)/L; P= .04). CONCLUSIONS: The paucity of specific retinal findings associated with disease severity in knowlesi malaria contrasts with the retinopathy of severe adult falciparum malaria with and without coma, suggesting that falciparum-like microvascular sequestration in the brain is not a major component in severe knowlesi malaria pathogenesis.

Moore KA, Simpson JA, Paw MK, Pimanpanarak M, Wiladphaingern J, Rijken MJ, Jittamala P, White NJ, Fowkes FJI, Nosten F, McGready R. 2016. Safety of artemisinins in first trimester of prospectively followed pregnancies: an observational study. Lancet Infect Dis, 16 (5), pp. 576-583. | Citations: 18 (Scopus) | Show Abstract | Read more

BACKGROUND: Artemisinins, the most effective antimalarials available, are not recommended for falciparum malaria during the first trimester of pregnancy because of safety concerns. Therefore, quinine is used despite its poor effectiveness. Assessing artemisinin safety requires weighing the risks of malaria and its treatment. We aimed to assess the effect of first-trimester malaria and artemisinin treatment on miscarriage and major congenital malformations. METHODS: In this observational study, we assessed data from antenatal clinics on the Thai-Myanmar border between Jan 1, 1994, and Dec 31, 2013. We included women who presented to antenatal clinics during their first trimester with a viable fetus. Women were screened for malaria, and data on malaria, antimalarial treatment, and birth outcomes were collected. The relationship between artemisinin treatments (artesunate, dihydroartemisinin, or artemether) and miscarriage or malformation was assessed using Cox regression with left-truncation and time-varying exposures. FINDINGS: Of 55 636 pregnancies registered between 1994 and 2013, 25 485 pregnancies were analysed for first-trimester malaria and miscarriage, in which 2558 (10%) had first-trimester malaria. The hazard of miscarriage increased 1·61-fold after an initial first-trimester falciparum episode (95% CI 1·32-1·97; p<0·0001), 3·24-fold following falciparum recurrence (2·24-4·68; p<0·0001), and 2·44-fold (1·01-5·88; p=0·0473) following recurrent symptomatic vivax malaria. No difference was noted in miscarriage in first-line falciparum treatments with artemisinin (n=183) versus quinine (n=842; HR 0·78 [95% CI 0·45-1·34]; p=0·3645) or in risk of major congenital malformations (two [2%] of 109 [95% CI 0·22-6·47] versus eight (1%) of 641 [0·54-2·44], respectively). INTERPRETATION: First-trimester falciparum and vivax malaria both increase the risk of miscarriage. We noted no evidence of an increased risk of miscarriage or of major congenital malformations associated with first-line treatment with an artemisinin derivative compared with quinine. In view of the low efficacy of quinine and wide availability of highly effective artemisinin-based combination therapies, it is time to reconsider first-trimester antimalarial treatment recommendations. FUNDING: The Wellcome Trust and The Bill & Melinda Gates Foundation.

Tuti T, Bitok M, Malla L, Paton C, Muinga N, Gathara D, Gachau S, Mbevi G, Nyachiro W, Ogero M et al. 2016. Improving documentation of clinical care within a clinical information network: an essential initial step in efforts to understand and improve care in Kenyan hospitals. BMJ Glob Health, 1 (1), pp. e000028. | Show Abstract | Read more

In many low income countries health information systems are poorly equipped to provide detailed information on hospital care and outcomes. Information is thus rarely used to support practice improvement. We describe efforts to tackle this challenge and to foster learning concerning collection and use of information. This could improve hospital services in Kenya. We are developing a Clinical Information Network, a collaboration spanning 14 hospitals, policy makers and researchers with the goal of improving information available on the quality of inpatient paediatric care across common childhood illnesses in Kenya. Standardised data from hospitals' paediatric wards are collected using non-commercial and open source tools. We have implemented procedures for promoting data quality which are performed prior to a process of semi-automated analysis and routine report generation for hospitals in the network. In the first phase of the Clinical Information Network, we collected data on over 65 000 admission episodes. Despite clinicians' initial unfamiliarity with routine performance reporting, we found that, as an initial focus, both engaging with each hospital and providing them information helped improve the quality of data and therefore reports. The process has involved mutual learning and building of trust in the data and should provide the basis for collaborative efforts to improve care, to understand patient outcome, and to evaluate interventions through shared learning. We have found that hospitals are willing to support the development of a clinically focused but geographically dispersed Clinical Information Network in a low-income setting. Such networks show considerable promise as platforms for collaborative efforts to improve care, to provide better information for decision making, and to enable locally relevant research.

Bousfield R, Thyl M, Samol O, Rithea L, Sona S, Chhat HP, Poda S, Moore CE, Chheng K, Kumar V et al. 2016. A retrospective study of factors which determine a negative blood culture in Cambodian children diagnosed with enteric fever. Paediatr Int Child Health, 36 (2), pp. 118-121. | Show Abstract | Read more

BACKGROUND: Blood cultures are used to confirm a diagnosis of enteric fever but reported sensitivities can be as low as 40%. AIMS: To determine the factors associated with a negative blood culture in Cambodian children with suspected enteric fever. METHODS: In a retrospective study of hospitalised Cambodian children given a discharge diagnosis of enteric fever, the following factors associated with a negative blood culture were analysed: age, blood culture volume, prior antibiotic therapy, duration of illness and disease severity. RESULTS: In 227 hospitalised Cambodian children with a discharge diagnosis of enteric fever, it was confirmed in 70% by a positive blood culture. There was no association between a negative blood culture and younger age, lower blood volumes for culture, prior antibiotic therapy, a late presentation or milder disease. CONCLUSIONS: Although blood culture sensitivity was higher than expected, alternative simple, rapid and sensitive tests are needed for diagnosing enteric fever.

Moore CE, Sona S, Poda S, Putchhat H, Kumar V, Sopheary S, Stoesser N, Bousfield R, Day N, Parry CM. 2016. Antimicrobial susceptibility of uropathogens isolated from Cambodian children. Paediatr Int Child Health, 36 (2), pp. 113-117. | Citations: 7 (Scopus) | Show Abstract | Read more

BACKGROUND: Bacterial resistance to commonly used antimicrobials is an increasing problem in Asia but information concerning the antimicrobial susceptibility of bacteria causing urinary tract infections (UTIs) in children is limited. METHODS: This was a 5-year retrospective study of children with suspected UTI attending a paediatric hospital in north-west Cambodia. Urines with a positive culture containing a single organism with a count of >10(5) colony-forming units (CFU)/ml were considered diagnostic of infection. The organism was identified and the resistance pattern (using CLSI guidelines) and presence of an extended-spectrum β-lactamase (ESBL) phenotype was determined. RESULTS: In total, there were 217 episodes of infection, 210 (97%) with Gram-negative bacteria. Escherichia coli was the most common infecting isolate with high levels of resistance to most oral antibiotics, except nitrofurantoin. Nearly half of the E. coli (44%) were extended-spectrum cephalosporin (ESC)-resistant with the proportion increasing significantly over the 5-year period. ESC-resistant E. coli were more likely to be multi-drug-resistant and 91% demonstrated an ESBL phenotype. CONCLUSION: The data highlight the importance of microbiological surveillance of UTIs in children, particularly in areas where there are known to be multiply resistant organisms.

Khor CC, Do T, Jia H, Nakano M, George R, Abu-Amero K, Duvesh R, Chen LJ, Li Z, Nongpiur ME et al. 2016. Genome-wide association study identifies five new susceptibility loci for primary angle closure glaucoma. Nat Genet, 48 (5), pp. 556-562. | Citations: 23 (Web of Science Lite) | Show Abstract | Read more

Primary angle closure glaucoma (PACG) is a major cause of blindness worldwide. We conducted a genome-wide association study (GWAS) followed by replication in a combined total of 10,503 PACG cases and 29,567 controls drawn from 24 countries across Asia, Australia, Europe, North America, and South America. We observed significant evidence of disease association at five new genetic loci upon meta-analysis of all patient collections. These loci are at EPDR1 rs3816415 (odds ratio (OR) = 1.24, P = 5.94 × 10(-15)), CHAT rs1258267 (OR = 1.22, P = 2.85 × 10(-16)), GLIS3 rs736893 (OR = 1.18, P = 1.43 × 10(-14)), FERMT2 rs7494379 (OR = 1.14, P = 3.43 × 10(-11)), and DPM2-FAM102A rs3739821 (OR = 1.15, P = 8.32 × 10(-12)). We also confirmed significant association at three previously described loci (P < 5 × 10(-8) for each sentinel SNP at PLEKHA7, COL11A1, and PCMTD1-ST18), providing new insights into the biology of PACG.

Hope-Gill B, Idriss B, Massaquoi T, Horby P. 2016. Teaching research methodology within an Ebola virus outbreak. Med Educ, 50 (5), pp. 584-585. | Read more

Phetsouvanh R, Sonthayanon P, Pukrittayakamee S, Paris DH, Newton PN, Feil EJ, Day NPJ. 2016. Correction: The Diversity and Geographical Structure of Orientia tsutsugamushi Strains from Scrub Typhus Patients in Laos. PLoS Negl Trop Dis, 10 (5), pp. e0004742. | Show Abstract | Read more

[This corrects the article DOI: 10.1371/journal.pntd.0004024.].

Last M, Tosas O, Gallo Cassarino T, Kozlakidis Z, Edgeworth J. 2016. Evolving classification of intensive care patients from event data Artificial Intelligence in Medicine, 69 pp. 22-32. | Read more

Hughes J, Goldenberg SD, Tosas O, Edgeworth JD, Otter JA. 2016. Recent emergence of carbapenem-resistant organisms in a low prevalence UK setting in London Journal of Infection Prevention, 17 (3), pp. 130-134. | Read more

Marsh K. 2016. Africa in transition: the case of malaria. Int Health, 8 (3), pp. 155-156. | Citations: 3 (Web of Science Lite) | Read more

Clapham HE, Rodriguez-Barraquer I, Azman AS, Althouse BM, Salje H, Gibbons RV, Rothman AL, Jarman RG, Nisalak A, Thaisomboonsuk B et al. 2016. Dengue Virus (DENV) Neutralizing Antibody Kinetics in Children After Symptomatic Primary and Postprimary DENV Infection. J Infect Dis, 213 (9), pp. 1428-1435. | Show Abstract | Read more

The immune response to dengue virus (DENV) infection is complex and not fully understood. Using longitudinal data from 181 children with dengue in Thailand who were followed for up to 3 years, we describe neutralizing antibody kinetics following symptomatic DENV infection. We observed that antibody titers varied by serotype, homotypic vs heterotypic responses, and primary versus postprimary infections. The rates of change in antibody titers over time varied between primary and postprimary responses. For primary infections, titers increased from convalescence to 6 months. By comparing homotypic and heterotypic antibody titers, we saw an increase in type specificity from convalescence to 6 months for primary DENV3 infections but not primary DENV1 infections. In postprimary cases, there was a decrease in titers from convalescence up until 6 months after infection. Beginning 1 year after both primary and postprimary infections, there was evidence of increasing antibody titers, with greater increases in children with lower titers, suggesting that antibody titers were boosted due to infection and that higher levels of neutralizing antibody may be more likely to confer a sterilizing immune response. These findings may help to model virus transmission dynamics and provide baseline data to support the development of vaccines and therapeutics.

Clapham HE, Rodriguez-Barraquer I, Azman AS, Althouse BM, Salje H, Gibbons RV, Rothman AL, Jarman RG, Nisalak A, Thaisomboonsuk B et al. 2016. Dengue Virus (DENV) Neutralizing Antibody Kinetics in Children after Symptomatic Primary and Postprimary DENV Infection Journal of Infectious Diseases, 213 (9), pp. 1428-1435. | Citations: 6 (Scopus) | Show Abstract | Read more

© 2015 The Author 2015. The immune response to dengue virus (DENV) infection is complex and not fully understood. Using longitudinal data from 181 children with dengue in Thailand who were followed for up to 3 years, we describe neutralizing antibody kinetics following symptomatic DENV infection. We observed that antibody titers varied by serotype, homotypic vs heterotypic responses, and primary versus postprimary infections. The rates of change in antibody titers over time varied between primary and postprimary responses. For primary infections, titers increased from convalescence to 6 months. By comparing homotypic and heterotypic antibody titers, we saw an increase in type specificity from convalescence to 6 months for primary DENV3 infections but not primary DENV1 infections. In postprimary cases, there was a decrease in titers from convalescence up until 6 months after infection. Beginning 1 year after both primary and postprimary infections, there was evidence of increasing antibody titers, with greater increases in children with lower titers, suggesting that antibody titers were boosted due to infection and that higher levels of neutralizing antibody may be more likely to confer a sterilizing immune response. These findings may help to model virus transmission dynamics and provide baseline data to support the development of vaccines and therapeutics.

TenoRes Study Group. 2016. Global epidemiology of drug resistance after failure of WHO recommended first-line regimens for adult HIV-1 infection: a multicentre retrospective cohort study. Lancet Infect Dis, 16 (5), pp. 565-575. | Citations: 42 (Scopus) | Show Abstract | Read more

BACKGROUND: Antiretroviral therapy (ART) is crucial for controlling HIV-1 infection through wide-scale treatment as prevention and pre-exposure prophylaxis (PrEP). Potent tenofovir disoproxil fumarate-containing regimens are increasingly used to treat and prevent HIV, although few data exist for frequency and risk factors of acquired drug resistance in regions hardest hit by the HIV pandemic. We aimed to do a global assessment of drug resistance after virological failure with first-line tenofovir-containing ART. METHODS: The TenoRes collaboration comprises adult HIV treatment cohorts and clinical trials of HIV drug resistance testing in Europe, Latin and North America, sub-Saharan Africa, and Asia. We extracted and harmonised data for patients undergoing genotypic resistance testing after virological failure with a first-line regimen containing tenofovir plus a cytosine analogue (lamivudine or emtricitabine) plus a non-nucleotide reverse-transcriptase inhibitor (NNRTI; efavirenz or nevirapine). We used an individual participant-level meta-analysis and multiple logistic regression to identify covariates associated with drug resistance. Our primary outcome was tenofovir resistance, defined as presence of K65R/N or K70E/G/Q mutations in the reverse transcriptase (RT) gene. FINDINGS: We included 1926 patients from 36 countries with treatment failure between 1998 and 2015. Prevalence of tenofovir resistance was highest in sub-Saharan Africa (370/654 [57%]). Pre-ART CD4 cell count was the covariate most strongly associated with the development of tenofovir resistance (odds ratio [OR] 1·50, 95% CI 1·27-1·77 for CD4 cell count <100 cells per μL). Use of lamivudine versus emtricitabine increased the risk of tenofovir resistance across regions (OR 1·48, 95% CI 1·20-1·82). Of 700 individuals with tenofovir resistance, 578 (83%) had cytosine analogue resistance (M184V/I mutation), 543 (78%) had major NNRTI resistance, and 457 (65%) had both. The mean plasma viral load at virological failure was similar in individuals with and without tenofovir resistance (145 700 copies per mL [SE 12 480] versus 133 900 copies per mL [SE 16 650; p=0·626]). INTERPRETATION: We recorded drug resistance in a high proportion of patients after virological failure on a tenofovir-containing first-line regimen across low-income and middle-income regions. Effective surveillance for transmission of drug resistance is crucial. FUNDING: The Wellcome Trust.

Fellmeth G, Paw MK, Wiladphaingern J, Charunwatthana P, Nosten FH, McGready R. 2016. Maternal suicide risk among refugees and migrants. Int J Gynaecol Obstet, 134 (2), pp. 223-224. | Citations: 2 (Scopus) | Read more

Talbert AW, Ngari M, Tsofa B, Mramba L, Mumbo E, Berkley JA, Mwangome M. 2016. "When you give birth you will not be without your mother" A mixed methods study of advice on breastfeeding for first-time mothers in rural coastal Kenya. Int Breastfeed J, 11 (1), pp. 10. | Citations: 1 (Scopus) | Show Abstract | Read more

BACKGROUND: Exclusive breastfeeding for the first 6 months of life is currently recommended by the World Health Organization, but mixed feeding earlier than this commonly occurs in rural coastal Kenya. Mothers may receive conflicting advice on breastfeeding from various sources including health workers, relatives and community members. We aimed to find out how first-time mothers learn to breastfeed, who advises them on infant feeding and what advice they obtain in case of any breastfeeding problems. METHODS: To identify advisers, a questionnaire on socio-demographic status, place of delivery, household members, education and help received on breastfeeding, breastfeeding problems, name of advisers and their relationship to the mothers was administered to 50 new first-time mothers in Jaribuni, Kilifi (population approximately 18,000). Summary statistics were obtained using frequencies, medians and interquartile ranges (IQR). Focus group discussions (FGDs) were held amongst 4 groups of mothers who had answered questionnaires; 4 groups of their named advisers; and 1 group of community health workers in order to explore breastfeeding practices, problems and advice given. FGDs were analysed by thematic framework analysis. RESULTS: First-time mothers were young (median age 18, IQR 17-21, range 14-26 years) and 42 % were single. Living in extended families was the norm and married women lived with their husband's family. All had a female family member or neighbour helping with childcare in the perinatal period. The main advisers on breastfeeding were their mother or older female members of their husband's family. Married first-time mothers felt obliged to follow their mother-in-law's advice to maintain good relationships and show respect within the household. Breastfeeding problems were reported by 80 % of respondents. Nipple pain (56 %) was the most reported problem, then breast engorgement (48 %) and insufficient milk supply (38 %). Most problems were treated at home without consultation with health workers. Concerns were raised about co-sleeping, breastfeeding whilst lying down, and insufficient milk supply. Advisers would like more information on breastfeeding in order to help mothers. CONCLUSIONS: Interventions to increase knowledge of, and facilitate optimal breastfeeding practices in first-time mothers should include those family members who advise and assist with childcare around the time of delivery.

Peto TJ, Kloprogge SE, Tripura R, Nguon C, Sanann N, Yok S, Heng C, Promnarate C, Chalk J, Song N et al. 2016. History of malaria treatment as a predictor of subsequent subclinical parasitaemia: a cross-sectional survey and malaria case records from three villages in Pailin, western Cambodia. Malar J, 15 (1), pp. 240. | Citations: 5 (Scopus) | Show Abstract | Read more

BACKGROUND: Treatment of the sub-clinical reservoir of malaria, which may maintain transmission, could be an important component of elimination strategies. The reliable detection of asymptomatic infections with low levels of parasitaemia requires high-volume quantitative polymerase chain reaction (uPCR), which is impractical to conduct on a large scale. It is unknown to what extent sub-clinical parasitaemias originate from recent or older clinical episodes. This study explored the association between clinical history of malaria and subsequent sub-clinical parasitaemia. METHODS: In June 2013 a cross-sectional survey was conducted in three villages in Pailin, western Cambodia. Demographic and epidemiological data and blood samples were collected. Blood was tested for malaria by high-volume qPCR. Positive samples were analysed by nested PCR to determine the Plasmodium species. To identify previous episodes of malaria, case records were collected from village malaria workers and local health facilities and linked to study participants. RESULTS: Among 1343 participants, 40/122 (32.8 %) with a history of clinical malaria were parasitaemic during the cross-sectional survey, compared to 172/1221 (14.1 %) without this history (p < 0.001). Among the 212 parasitaemic participants in the survey, 40 (18.9 %) had a history of clinical malaria, compared to 87 out of 1131 (7.7 %) parasite-negative participants; p < 0.001, adjusted OR 3.3 (95 % CI; 2.1-5.1). A history of Plasmodium vivax was associated with sub-clinical P. vivax parasitaemia in the survey (p < 0.001), but this association was not seen with Plasmodium falciparum (p = 0.253); only three participants had both P. falciparum parasites in the survey and a clinical history of P. falciparum. CONCLUSIONS: A clinical episode of vivax malaria was associated with subsequent sub-clinical parasitaemia. Treatment of P. vivax with artemisinin-based combination therapy without primaquine often resulted in recurrent episodes. Targeting individuals with a history of clinical malaria will be insufficient to eliminate the sub-clinical reservoir as they constitute a minority of parasitaemias.

Morgan R, George A, Ssali S, Hawkins K, Molyneux S, Theobald S. 2016. How to do (or not to do)… gender analysis in health systems research. Health Policy Plan, 31 (8), pp. 1069-1078. | Citations: 4 (Scopus) | Show Abstract | Read more

Gender-the socially constructed roles, behaviours, activities and attributes that a given society considers appropriate for males, females and other genders-affects how people live, work and relate to each other at all levels, including in relation to the health system. Health systems research (HSR) aims to inform more strategic, effective and equitable health systems interventions, programs and policies; and the inclusion of gender analysis into HSR is a core part of that endeavour. We outline what gender analysis is and how gender analysis can be incorporated into HSR content, process and outcomes Starting with HSR content, i.e. the substantive focus of HSR, we recommend exploring whether and how gender power relations affect females and males in health systems through the use of sex disaggregated data, gender frameworks and questions. Sex disaggregation flags female-male differences or similarities that warrant further analysis; and further analysis is guided by gender frameworks and questions to understand how gender power relations are constituted and negotiated in health systems. Critical aspects of understanding gender power relations include examining who has what (access to resources); who does what (the division of labour and everyday practices); how values are defined (social norms) and who decides (rules and decision-making). Secondly, we examine gender in HSR process by reflecting on how the research process itself is imbued with power relations. We focus on data collection and analysis by reviewing who participates as respondents; when data is collected and where; who is present; who collects data and who analyses data. Thirdly, we consider gender and HSR outcomes by considering who is empowered and disempowered as a result of HSR, including the extent to which HSR outcomes progressively transform gender power relations in health systems, or at least do not further exacerbate them.

Nakeesathit S, Saralamba N, Pukrittayakamee S, Dondorp A, Nosten F, White NJ, Imwong M. 2016. Limited Polymorphism of the Kelch Propeller Domain in Plasmodium malariae and P. ovale Isolates from Thailand. Antimicrob Agents Chemother, 60 (7), pp. 4055-4062. | Citations: 1 (Web of Science Lite) | Show Abstract | Read more

Artemisinin resistance in Plasmodium falciparum, the agent of severe malaria, is currently a major obstacle to malaria control in Southeast Asia. A gene named "kelch13" has been associated with artemisinin resistance in P. falciparum The orthologue of the kelch gene in P. vivax was identified and a small number of mutations were found in previous studies. The kelch orthologues in the other two human malaria parasites, P. malariae and P. ovale, have not yet been studied. Therefore, in this study, the orthologous kelch genes of P. malariae, P. ovale wallikeri, and P. ovale curtisi were isolated and analyzed for the first time. The homologies of the kelch genes of P. malariae and P. ovale were 84.8% and 82.7%, respectively, compared to the gene in P. falciparum kelch polymorphisms were studied in 13 P. malariae and 5 P. ovale isolates from Thailand. There were 2 nonsynonymous mutations found in these samples. One mutation was P533L, which was found in 1 of 13 P. malariae isolates, and the other was K137R, found in 1 isolate of P. ovale wallikeri (n = 4). This result needs to be considered in the context of widespread artemisinin used within the region; their functional consequences for artemisinin sensitivity in P. malariae and P. ovale will need to be elucidated.

Dunning J, Sahr F, Rojek A, Gannon F, Carson G, Idriss B, Massaquoi T, Gandi R, Joseph S, Osman HK et al. 2016. Experimental Treatment of Ebola Virus Disease with TKM-130803: A Single-Arm Phase 2 Clinical Trial. PLoS Med, 13 (4), pp. e1001997. | Citations: 40 (Scopus) | Show Abstract | Read more

BACKGROUND: TKM-130803, a small interfering RNA lipid nanoparticle product, has been developed for the treatment of Ebola virus disease (EVD), but its efficacy and safety in humans has not been evaluated. METHODS AND FINDINGS: In this single-arm phase 2 trial, adults with laboratory-confirmed EVD received 0.3 mg/kg of TKM-130803 by intravenous infusion once daily for up to 7 d. On days when trial enrolment capacity was reached, patients were enrolled into a concurrent observational cohort. The primary outcome was survival to day 14 after admission, excluding patients who died within 48 h of admission. After 14 adults with EVD had received TKM-130803, the pre-specified futility boundary was reached, indicating a probability of survival to day 14 of ≤0.55, and enrolment was stopped. Pre-treatment geometric mean Ebola virus load in the 14 TKM-130803 recipients was 2.24 × 109 RNA copies/ml plasma (95% CI 7.52 × 108, 6.66 × 109). Two of the TKM-130803 recipients died within 48 h of admission and were therefore excluded from the primary outcome analysis. Of the remaining 12 TKM-130803 recipients, nine died and three survived. The probability that a TKM-130803 recipient who survived for 48 h will subsequently survive to day 14 was estimated to be 0.27 (95% CI 0.06, 0.58). TKM-130803 infusions were well tolerated, with 56 doses administered and only one possible infusion-related reaction observed. Three patients were enrolled in the observational cohort, of whom two died. CONCLUSIONS: Administration of TKM-130803 at a dose of 0.3 mg/kg/d by intravenous infusion to adult patients with severe EVD was not shown to improve survival when compared to historic controls. TRIAL REGISTRATION: Pan African Clinical Trials Registry PACTR201501000997429.

Milligan ID, Gibani MM, Sewell R, Clutterbuck EA, Campbell D, Plested E, Nuthall E, Voysey M, Silva-Reyes L, McElrath MJ et al. 2016. Safety and Immunogenicity of Novel Adenovirus Type 26- and Modified Vaccinia Ankara-Vectored Ebola Vaccines: A Randomized Clinical Trial. JAMA, 315 (15), pp. 1610-1623. | Citations: 35 (Scopus) | Show Abstract | Read more

IMPORTANCE: Developing effective vaccines against Ebola virus is a global priority. OBJECTIVE: To evaluate an adenovirus type 26 vector vaccine encoding Ebola glycoprotein (Ad26.ZEBOV) and a modified vaccinia Ankara vector vaccine, encoding glycoproteins from Ebola virus, Sudan virus, Marburg virus, and Tai Forest virus nucleoprotein (MVA-BN-Filo). DESIGN, SETTING, AND PARTICIPANTS: Single-center, randomized, placebo-controlled, observer-blind, phase 1 trial performed in Oxford, United Kingdom, enrolling healthy 18- to 50-year-olds from December 2014; 8-month follow-up was completed October 2015. INTERVENTIONS: Participants were randomized into 4 groups, within which they were simultaneously randomized 5:1 to receive study vaccines or placebo. Those receiving active vaccines were primed with Ad26.ZEBOV (5 × 10(10) viral particles) or MVA-BN-Filo (1 × 10(8) median tissue culture infective dose) and boosted with the alternative vaccine 28 or 56 days later. A fifth, open-label group received Ad26.ZEBOV boosted by MVA-BN-Filo 14 days later. MAIN OUTCOMES AND MEASURES: The primary outcomes were safety and tolerability. All adverse events were recorded until 21 days after each immunization; serious adverse events were recorded throughout the trial. Secondary outcomes were humoral and cellular immune responses to immunization, as assessed by enzyme-linked immunosorbent assay and enzyme-linked immunospot performed at baseline and from 7 days after each immunization until 8 months after priming immunizations. RESULTS: Among 87 study participants (median age, 38.5 years; 66.7% female), 72 were randomized into 4 groups of 18, and 15 were included in the open-label group. Four participants did not receive a booster dose; 67 of 75 study vaccine recipients were followed up at 8 months. No vaccine-related serious adverse events occurred. No participant became febrile after MVA-BN-Filo, compared with 3 of 60 participants (5%; 95% CI, 1%-14%) receiving Ad26.ZEBOV in the randomized groups. In the open-label group, 4 of 15 Ad26.ZEBOV recipients (27%; 95% CI, 8%-55%) experienced fever. In the randomized groups, 28 of 29 Ad26.ZEBOV recipients (97%; 95% CI, 82%- 99.9%) and 7 of 30 MVA-BN-Filo recipients (23%; 95% CI, 10%-42%) had detectable Ebola glycoprotein-specific IgG 28 days after primary immunization. All vaccine recipients had specific IgG detectable 21 days postboost and at 8-month follow-up. Within randomized groups, at 7 days postboost, at least 86% of vaccine recipients showed Ebola-specific T-cell responses. CONCLUSIONS AND RELEVANCE: In this phase 1 study of healthy volunteers, immunization with Ad26.ZEBOV or MVA-BN-Filo did not result in any vaccine-related serious adverse events. An immune response was observed after primary immunization with Ad26.ZEBOV; boosting by MVA-BN-Filo resulted in sustained elevation of specific immunity. These vaccines are being further assessed in phase 2 and 3 studies. TRIAL REGISTRATION: Identifier: NCT02313077.

Kangoye DT, Noor A, Midega J, Mwongeli J, Mkabili D, Mogeni P, Kerubo C, Akoo P, Mwangangi J, Drakeley C et al. 2016. Malaria hotspots defined by clinical malaria, asymptomatic carriage, PCR and vector numbers in a low transmission area on the Kenyan Coast. Malar J, 15 (1), pp. 213. | Citations: 10 (Scopus) | Show Abstract | Read more

BACKGROUND: Targeted malaria control interventions are expected to be cost-effective. Clinical, parasitological and serological markers of malaria transmission have been used to detect malaria transmission hotspots, but few studies have examined the relationship between the different potential markers in low transmission areas. The present study reports on the relationships between clinical, parasitological, serological and entomological markers of malaria transmission in an area of low transmission intensity in Coastal Kenya. METHODS: Longitudinal data collected from 831 children aged 5-17 months, cross-sectional survey data from 800 older children and adults, and entomological survey data collected in Ganze on the Kenyan Coast were used in the present study. The spatial scan statistic test used to detect malaria transmission hotspots was based on incidence of clinical malaria episodes, prevalence of asymptomatic asexual parasites carriage detected by microscopy and polymerase chain reaction (PCR), seroprevalence of antibodies to two Plasmodium falciparum merozoite antigens (AMA1 and MSP1-19) and densities of Anopheles mosquitoes in CDC light-trap catches. RESULTS: There was considerable overlapping of hotspots by these different markers, but only weak to moderate correlation between parasitological and serological markers. PCR prevalence and seroprevalence of antibodies to AMA1 or MSP1-19 appeared to be more sensitive markers of hotspots at very low transmission intensity. CONCLUSION: These findings may support the choice of either serology or PCR as markers in the detection of malaria transmission hotspots for targeted interventions.

Lybbert J, Gullingsrud J, Chesnokov O, Turyakira E, Dhorda M, Guerin PJ, Piola P, Muehlenbachs A, Oleinikov AV. 2016. Abundance of megalin and Dab2 is reduced in syncytiotrophoblast during placental malaria, which may contribute to low birth weight. Sci Rep, 6 (1), pp. 24508. | Citations: 2 (Web of Science Lite) | Show Abstract | Read more

Placental malaria caused by Plasmodium falciparum contributes to ~200,000 child deaths annually, mainly due to low birth weight (LBW). Parasitized erythrocyte sequestration and consequent inflammation in the placenta are common attributes of placental malaria. The precise molecular details of placental changes leading to LBW are still poorly understood. We hypothesized that placental malaria may disturb maternofetal exchange of vitamins, lipids, and hormones mediated by the multi-ligand (n ~ 50) scavenging/signaling receptor megalin, which is abundantly expressed in placenta but was not previously analyzed in pregnancy outcomes. We studied abundance of megalin and its intracellular adaptor protein Dab2 by immunofluorescence microscopy in placental biopsies from Ugandan women with (n = 8) and without (n = 20) active placental malaria. We found that: (a) abundances of both megalin (p = 0.01) and Dab2 (p = 0.006) were significantly reduced in brush border of syncytiotrophoblast of infected placentas; (b) amounts of megalin and Dab2 were strongly correlated (Spearman's r = 0.53, p = 0.003); (c) abundances of megalin and Dab2 (p = 0.046) were reduced in infected placentas from women with LBW deliveries. This study provides first evidence that placental malaria infection is associated with reduced abundance of megalin transport/signaling system and indicate that these changes may contribute to the pathology of LBW.

Holt HR, Inthavong P, Khamlome B, Blaszak K, Keokamphe C, Somoulay V, Phongmany A, Durr PA, Graham K, Allen J et al. 2016. Endemicity of Zoonotic Diseases in Pigs and Humans in Lowland and Upland Lao PDR: Identification of Socio-cultural Risk Factors. PLoS Negl Trop Dis, 10 (4), pp. e0003913. | Citations: 6 (Scopus) | Show Abstract | Read more

In Lao People's Democratic Republic pigs are kept in close contact with families. Human risk of infection with pig zoonoses arises from direct contact and consumption of unsafe pig products. This cross-sectional study was conducted in Luang Prabang (north) and Savannakhet (central-south) Provinces. A total of 59 villages, 895 humans and 647 pigs were sampled and serologically tested for zoonotic pathogens including: hepatitis E virus (HEV), Japanese encephalitis virus (JEV) and Trichinella spiralis; In addition, human sera were tested for Taenia spp. and cysticercosis. Seroprevalence of zoonotic pathogens in humans was high for HEV (Luang Prabang: 48.6%, Savannakhet: 77.7%) and T. spiralis (Luang Prabang: 59.0%, Savannakhet: 40.5%), and lower for JEV (around 5%), Taenia spp. (around 3%) and cysticercosis (Luang Prabang: 6.1, Savannakhet 1.5%). Multiple correspondence analysis and hierarchical clustering of principal components was performed on descriptive data of human hygiene practices, contact with pigs and consumption of pork products. Three clusters were identified: Cluster 1 had low pig contact and good hygiene practices, but had higher risk of T. spiralis. Most people in cluster 2 were involved in pig slaughter (83.7%), handled raw meat or offal (99.4%) and consumed raw pigs' blood (76.4%). Compared to cluster 1, cluster 2 had increased odds of testing seropositive for HEV and JEV. Cluster 3 had the lowest sanitation access and had the highest risk of HEV, cysticercosis and Taenia spp. Farmers which kept their pigs tethered (as opposed to penned) and disposed of manure in water sources had 0.85 (95% CI: 0.18 to 0.91) and 2.39 (95% CI: 1.07 to 5.34) times the odds of having pigs test seropositive for HEV, respectively. The results have been used to identify entry-points for intervention and management strategies to reduce disease exposure in humans and pigs, informing control activities in a cysticercosis hyper-endemic village.

Gosling R, von Seidlein L. 2016. The Future of the RTS,S/AS01 Malaria Vaccine: An Alternative Development Plan. PLoS Med, 13 (4), pp. e1001994. | Citations: 19 (Web of Science Lite) | Show Abstract | Read more

Roly Gosling and Lorenz von Seidlein consider a potential future development plan for the RTS,S/AS01 malaria vaccine.

Chansamouth V, Thammasack S, Phetsouvanh R, Keoluangkot V, Moore CE, Blacksell SD, Castonguay-Vanier J, Dubot-Pérès A, Tangkhabuanbutra J, Tongyoo N et al. 2016. The Aetiologies and Impact of Fever in Pregnant Inpatients in Vientiane, Laos. PLoS Negl Trop Dis, 10 (4), pp. e0004577. | Citations: 4 (Web of Science Lite) | Show Abstract | Read more

INTRODUCTION: Laos has the highest maternal mortality ratio in mainland Southeast Asia and a high incidence of infectious diseases. Globally, malaria has been the pathogen most intensively investigated in relation to impact on pregnancy, but there has been relatively little research on the aetiology and impact of other diseases. We therefore aimed to determine the causes and impact of fever in pregnant women admitted to two central hospitals in Vientiane City, Lao PDR (Laos). MATERIALS AND METHODS: This hospital-based prospective study was conducted in Mahosot Hospital and the Mother and Child Hospital, Vientiane, between 2006 and 2010, with the aim to recruit 250 consenting pregnant women admitted with tympanic temperature ≥37.5°C. Primary outcome was the cause of fever and secondary outcomes were pregnancy outcomes. Specific investigations (culture, antigen, molecular and serological tests) were performed to investigate causes of fever. After discharge, all pregnant women were asked to return for review and convalescence serum on day 10-14 and were monitored until delivery. PRINCIPLE FINDINGS: 250 pregnant women were recruited to this study between February 2006 and November 2010. Fifty percent were pregnant for the first time. Their median (range) gestational age on admission was 24 (4-43) weeks. The median (range) tympanic admission temperature was 38.5°C (37.5-40.5°C). Fifteen percent of patients stated that they had taken antibiotics before admission. Headache, myalgia, back pain and arthralgia were described by >60% of patients and 149 (60%) were given a laboratory diagnosis. Of those with confirmed diagnoses, 132 (53%) had a single disease and 17 (7%) had apparent mixed diseases. Among those who had a single disease, dengue fever was the most common diagnosis, followed by pyelonephritis, scrub typhus, murine typhus and typhoid. Patients were also diagnosed with tuberculosis, appendicitis, Staphylococcus aureus septicemia, leptospirosis, Japanese encephalitis virus infection and Plasmodium falciparum malaria. Severe consequences, including maternal death, miscarriage, stillbirth, low birth weight and preterm birth, were found among 28 (78%) mothers with dengue fever, rickettsioses and typhoid. CONCLUSION: Fevers other than malaria, such as dengue, pyelonephritis, rickettsioses and typhoid are common causes of fever during pregnancy in the Asian tropics. Further investigations of their impact in the community on maternal death, fetal loss, vertical transmission, low birth weight and preterm birth are needed.

Imwong M, Stepniewska K, Tripura R, Peto TJ, Lwin KM, Vihokhern B, Wongsaen K, von Seidlein L, Dhorda M, Snounou G et al. 2016. Numerical Distributions of Parasite Densities During Asymptomatic Malaria. J Infect Dis, 213 (8), pp. 1322-1329. | Citations: 26 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Asymptomatic parasitemia is common even in areas of low seasonal malaria transmission, but the true proportion of the population infected has not been estimated previously because of the limited sensitivity of available detection methods. METHODS: Cross-sectional malaria surveys were conducted in areas of low seasonal transmission along the border between eastern Myanmar and northwestern Thailand and in western Cambodia. DNA was quantitated by an ultrasensitive polymerase chain reaction (uPCR) assay (limit of accurate detection, 22 parasites/mL) to characterize parasite density distributions for Plasmodium falciparum and Plasmodium vivax, and the proportions of undetected infections were imputed. RESULTS: The prevalence of asymptomatic malaria as determined by uPCR was 27.5% (1303 of 4740 people tested). Both P. vivax and P. falciparum density distributions were unimodal and log normal, with modal values well within the quantifiable range. The estimated proportions of all parasitemic individuals identified by uPCR were >70% among individuals infected with P. falciparum and >85% among those infected with P. vivax. Overall, 83% of infections were predicted to be P. vivax infections, 13% were predicted to be P. falciparum infections, and 4% were predicted to be mixed infections. Geometric mean parasite densities were similar; 5601 P. vivax parasites/mL and 5158 P. falciparum parasites/mL. CONCLUSIONS: This uPCR method identified most infected individuals in malaria-endemic areas. Malaria parasitemia persists in humans at levels that optimize the probability of generating transmissible gametocyte densities without causing illness.

Lessler J, Salje H, Van Kerkhove MD, Ferguson NM, Cauchemez S, Rodriquez-Barraquer I, Hakeem R, Jombart T, Aguas R, Al-Barrak A et al. 2016. Estimating the Severity and Subclinical Burden of Middle East Respiratory Syndrome Coronavirus Infection in the Kingdom of Saudi Arabia. Am J Epidemiol, 183 (7), pp. 657-663. | Citations: 9 (Scopus) | Show Abstract | Read more

Not all persons infected with Middle East respiratory syndrome coronavirus (MERS-CoV) develop severe symptoms, which likely leads to an underestimation of the number of people infected and an overestimation of the severity. To estimate the number of MERS-CoV infections that have occurred in the Kingdom of Saudi Arabia, we applied a statistical model to a line list describing 721 MERS-CoV infections detected between June 7, 2012, and July 25, 2014. We estimated that 1,528 (95% confidence interval (CI): 1,327, 1,883) MERS-CoV infections occurred in this interval, which is 2.1 (95% CI: 1.8, 2.6) times the number reported. The probability of developing symptoms ranged from 11% (95% CI: 4, 25) in persons under 10 years of age to 88% (95% CI: 72, 97) in those 70 years of age or older. An estimated 22% (95% CI: 18, 25) of those infected with MERS-CoV died. MERS-CoV is deadly, but this work shows that its clinical severity differs markedly between groups and that many cases likely go undiagnosed.

Thuan PD, Ca NTN, Van Toi P, Nhien NTT, Thanh NV, Anh ND, Phu NH, Thai CQ, Thai LH, Hoa NT et al. 2016. A Randomized Comparison of Chloroquine Versus Dihydroartemisinin-Piperaquine for the Treatment of Plasmodium vivax Infection in Vietnam. Am J Trop Med Hyg, 94 (4), pp. 879-885. | Citations: 1 (Scopus) | Show Abstract | Read more

A total of 128 Vietnamese patients with symptomatic Plasmodium vivax mono-infections were enrolled in a prospective, open-label, randomized trial to receive either chloroquine or dihydroartemisinin-piperaquine (DHA-PPQ). The proportions of patients with adequate clinical and parasitological responses were 47% in the chloroquine arm (31 of 65 patients) and 66% in the DHA-PPQ arm (42 of 63 patients) in the Kaplan-Meier intention-to-treat analysis (absolute difference 19%, 95% confidence interval = 0-37%), thus establishing non-inferiority of DHA-PPQ. Fever clearance time (median 24 versus 12 hours,P= 0.02), parasite clearance time (median 36 versus 18 hours,P< 0.001), and parasite clearance half-life (mean 3.98 versus 1.80 hours,P< 0.001) were all significantly shorter in the DHA-PPQ arm. All cases of recurrent parasitemia in the chloroquine arm occurred from day 33 onward, with corresponding whole blood chloroquine concentration lower than 100 ng/mL in all patients. Chloroquine thus remains efficacious for the treatment of P. vivax malaria in southern Vietnam, but DHA-PPQ provides more rapid symptomatic and parasitological recovery.

McGill F, Heyderman RS, Michael BD, Defres S, Beeching NJ, Borrow R, Glennie L, Gaillemin O, Wyncoll D, Kaczmarski E et al. 2016. The UK joint specialist societies guideline on the diagnosis and management of acute meningitis and meningococcal sepsis in immunocompetent adults. J Infect, 72 (4), pp. 405-438. | Citations: 26 (Scopus) | Show Abstract | Read more

Bacterial meningitis and meningococcal sepsis are rare conditions with high case fatality rates. Early recognition and prompt treatment saves lives. In 1999 the British Infection Society produced a consensus statement for the management of immunocompetent adults with meningitis and meningococcal sepsis. Since 1999 there have been many changes. We therefore set out to produce revised guidelines which provide a standardised evidence-based approach to the management of acute community acquired meningitis and meningococcal sepsis in adults. A working party consisting of infectious diseases physicians, neurologists, acute physicians, intensivists, microbiologists, public health experts and patient group representatives was formed. Key questions were identified and the literature reviewed. All recommendations were graded and agreed upon by the working party. The guidelines, which for the first time include viral meningitis, are written in accordance with the AGREE 2 tool and recommendations graded according to the GRADE system. Main changes from the original statement include the indications for pre-hospital antibiotics, timing of the lumbar puncture and the indications for neuroimaging. The list of investigations has been updated and more emphasis is placed on molecular diagnosis. Approaches to both antibiotic and steroid therapy have been revised. Several recommendations have been given regarding the follow-up of patients.

Dittrich S, Rudgard WE, Woods KL, Silisouk J, Phuklia W, Davong V, Vongsouvath M, Phommasone K, Rattanavong S, Knappik M et al. 2016. The Utility of Blood Culture Fluid for the Molecular Diagnosis of Leptospira: A Prospective Evaluation. Am J Trop Med Hyg, 94 (4), pp. 736-740. | Citations: 3 (Web of Science Lite) | Show Abstract | Read more

Leptospirosis is an important zoonosis worldwide, with infections occurring after exposure to contaminated water. Despite being a global problem, laboratory diagnosis remains difficult with culture results taking up to 3 months, serology being retrospective by nature, and polymerase chain reaction showing limited sensitivity. Leptospira have been shown to survive and multiply in blood culture media, and we hypothesized that extracting DNA from incubated blood culture fluid (BCF), followed by quantitative real-time polymerase chain reaction (qPCR) could improve the accuracy and speed of leptospira diagnosis. We assessed this retrospectively, using preincubated BCF of Leptospira spp. positive (N= 109) and negative (N= 63) febrile patients in Vientiane, Lao PDR. The final method showed promising sensitivities of 66% (95% confidence interval [CI]: 55-76) and 59% (95% CI: 49-68) compared with direct or direct and indirect testing combined, as the respective reference standards (specificities > 95%). Despite these promising diagnostic parameters, a subsequent prospective evaluation in a Lao hospital population (N= 352) showed that the sensitivity was very low (∼30%) compared with qPCR on venous blood samples. The disappointingly low sensitivity does suggest that venous blood samples are preferable for the clinical microbiology laboratory, although BCF might be an alternative if leptospirosis is only suspected postadmission after antibiotics have been used.

Beane A, Stephens T, Silva APD, Welch J, Sigera C, De Alwis S, Athapattu P, Dharmagunawardene D, Peiris L, Siriwardana S et al. 2016. A sustainable approach to training nurses in acute care skills in a resource limited setting (Network for Intensive Care Skills Training, NICST). Resuscitation, 101 pp. e1-e2. | Citations: 3 (Web of Science Lite) | Read more

Toda M, Njeru I, Zurovac D, O-Tipo S, Kareko D, Mwau M, Morita K. 2016. Effectiveness of a Mobile Short-Message-Service-Based Disease Outbreak Alert System in Kenya. Emerg Infect Dis, 22 (4), pp. 711-715. | Citations: 2 (Web of Science Lite) | Show Abstract | Read more

We conducted a randomized, controlled trial to test the effectiveness of a text-messaging system used for notification of disease outbreaks in Kenya. Health facilities that used the system had more timely notifications than those that did not (19.2% vs. 2.6%), indicating that technology can enhance disease surveillance in resource-limited settings.

Dulal P, Wright D, Ashfield R, Hill AVS, Charleston B, Warimwe GM. 2016. Potency of a thermostabilised chimpanzee adenovirus Rift Valley Fever vaccine in cattle. Vaccine, 34 (20), pp. 2296-2298. | Citations: 3 (Web of Science Lite) | Show Abstract | Read more

Development of safe and efficacious vaccines whose potency is unaffected by long-term storage at ambient temperature would obviate major vaccine deployment hurdles and limit wastage associated with breaks in the vaccine cold chain. Here, we evaluated the immunogenicity of a novel chimpanzee adenovirus vectored Rift Valley Fever vaccine (ChAdOx1-GnGc) in cattle, following its thermostabilisation by slow desiccation on glass fiber membranes in the non-reducing sugars trehalose and sucrose. Thermostabilised ChAdOx1-GnGc vaccine stored for 6 months at 25, 37 or 45 ° C elicited comparable Rift Valley Fever virus neutralising antibody titres to those elicited by the 'cold chain' vaccine (stored at -80 ° C throughout) at the same dose, and these were within the range associated with protection against Rift Valley Fever in cattle. The results support the use of sugar-membrane thermostabilised vaccines in target livestock species.

English M, Irimu G, Agweyu A, Gathara D, Oliwa J, Ayieko P, Were F, Paton C, Tunis S, Forrest CB. 2016. Building Learning Health Systems to Accelerate Research and Improve Outcomes of Clinical Care in Low- and Middle-Income Countries. PLoS Med, 13 (4), pp. e1001991. | Citations: 5 (Web of Science Lite) | Show Abstract | Read more

Mike English and colleagues argue that as efforts are made towards achieving universal health coverage it is also important to build capacity to develop regionally relevant evidence to improve healthcare.

Thuan PD, Ca NTN, Toi PV, Nhien NTT, Thanh NV, Anh ND, Phu NH, Thai CQ, Thai LH, Hoa NT et al. 2016. A Randomized Comparison of Chloroquine versus Dihydroartemisinin-Piperaquine for the Treatment of Plasmodium vivax Infection in Vietnam AMERICAN JOURNAL OF TROPICAL MEDICINE AND HYGIENE, 94 (4), pp. 879-885. | Citations: 1 (Web of Science Lite) | Read more

Atta H, Barwa C, Zamani G, Snow RW. 2016. Malaria and complex emergencies in the Eastern Mediterranean Region EASTERN MEDITERRANEAN HEALTH JOURNAL, 22 (4), pp. 235-236.

Bharucha T, Sengvilaipaseuth O, Chanthongthip A, Phuangpanom E, Phonemixay O, Vongsouvath M, Lee S, Newton P, Dubot-Peres A. 2016. Dried cerebrospinal fluid spots for diagnosing Japanese Encephalitis Virus (JEV) infection by Anti-JEV IgM antibody capture enzyme-linked immunosorbent assay: Harnessing the potential of a fully saturated pre-cut filter paper disc INTERNATIONAL JOURNAL OF INFECTIOUS DISEASES, 45 pp. 151-151. | Read more

Panzner U, Pak GD, Meyer CG, Ali M, Baker S, Clemens JD, Deerin JF, Gasmelseed N, Im J, Keddy KH et al. 2016. Typhoid fever surveillance in africa program (TSAP): Constructing a geospatial sampling frame for random sampling of households INTERNATIONAL JOURNAL OF INFECTIOUS DISEASES, 45 pp. 237-238. | Read more

Dance DAB. 2016. Challenges in diagnosis and management of melioidosis INTERNATIONAL JOURNAL OF INFECTIOUS DISEASES, 45 pp. 30-30. | Read more

Von Seidlein L. 2016. Malaria prevention strategies INTERNATIONAL JOURNAL OF INFECTIOUS DISEASES, 45 pp. 16-16. | Read more

Tun KM, Jeeyapant A, Imwong M, Thein M, Aung SSM, Hlaing TM, Yuentrakul P, Promnarate C, Dhorda M, Woodrow CJ et al. 2016. Parasite clearance rates in Upper Myanmar indicate a distinctive artemisinin resistance phenotype: a therapeutic efficacy study. Malar J, 15 (1), pp. 185. | Citations: 9 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Artemisinin resistance in Plasmodium falciparum extends across Southeast Asia where it is associated with worsening partner drug resistance and a decline in the efficacy of frontline artemisinin-based combination therapy. Dihydroartemisinin-piperaquine (DP) is an essential component of preventive and curative treatment in the region, but its therapeutic efficacy has fallen in Cambodia. METHODS: A prospective clinical and parasitological evaluation of DP was conducted at two sites in Upper Myanmar between August 2013 and December 2014, enrolling 116 patients with acute uncomplicated falciparum malaria. Patients received DP orally for 3 days together with primaquine 0.25 mg/kg on admission. Parasite clearance half-lives based on 6 hourly blood smears, and day 42 therapeutic responses were assessed as well as parasite K13 genotypes. RESULTS: Median parasite clearance half-life was prolonged, and clearance half-life was greater than 5 h in 21% of patients. Delayed parasite clearance was significantly associated with mutations in the propeller region of the parasite k13 gene. The k13 F446I mutation was found in 25.4% of infections and was associated with a median clearance half-life of 4.7 h compared with 2.7 h for infections without k13 mutations (p < 0.001). There were no failures after 42 days of follow-up, although 18% of patients had persistent parasitaemia on day 3. CONCLUSION: The dominant k13 mutation observed in Upper Myanmar, F446I, appears to be associated with an intermediate rate of parasite clearance compared to other common mutations described elsewhere in the Greater Mekong Subregion. Discerning this phenotype requires relatively detailed clearance measurements, highlighting the importance of methodology in assessing artemisinin resistance.

Worby CJ, O'Neill PD, Kypraios T, Robotham JV, De Angelis D, Cartwright EJP, Peacock SJ, Cooper BS. 2016. Reconstructing transmission trees for communicable diseases using densely sampled genetic data. Ann Appl Stat, 10 (1), pp. 395-417. | Citations: 6 (Scopus) | Show Abstract | Read more

Whole genome sequencing of pathogens from multiple hosts in an epidemic offers the potential to investigate who infected whom with unparalleled resolution, potentially yielding important insights into disease dynamics and the impact of control measures. We considered disease outbreaks in a setting with dense genomic sampling, and formulated stochastic epidemic models to investigate person-to-person transmission, based on observed genomic and epidemiological data. We constructed models in which the genetic distance between sampled genotypes depends on the epidemiological relationship between the hosts. A data augmented Markov chain Monte Carlo algorithm was used to sample over the transmission trees, providing a posterior probability for any given transmission route. We investigated the predictive performance of our methodology using simulated data, demonstrating high sensitivity and specificity, particularly for rapidly mutating pathogens with low transmissibility. We then analyzed data collected during an outbreak of methicillin-resistant Staphylococcus aureus in a hospital, identifying probable transmission routes and estimating epidemiological parameters. Our approach overcomes limitations of previous methods, providing a framework with the flexibility to allow for unobserved infection times, multiple independent introductions of the pathogen, and within-host genetic diversity, as well as allowing forward simulation.

Blacksell SD, Lim C, Tanganuchitcharnchai A, Jintaworn S, Kantipong P, Richards AL, Paris DH, Limmathurotsakul D, Day NPJ. 2016. Optimal Cutoff and Accuracy of an IgM Enzyme-Linked Immunosorbent Assay for Diagnosis of Acute Scrub Typhus in Northern Thailand: an Alternative Reference Method to the IgM Immunofluorescence Assay. J Clin Microbiol, 54 (6), pp. 1472-1478. | Citations: 3 (Web of Science Lite) | Show Abstract | Read more

The enzyme-linked immunosorbent assay (ELISA) has been proposed as an alternative serologic diagnostic test to the indirect immunofluorescence assay (IFA) for scrub typhus. Here, we systematically determine the optimal sample dilution and cutoff optical density (OD) and estimate the accuracy of IgM ELISA using Bayesian latent class models (LCMs). Data from 135 patients with undifferentiated fever were reevaluated using Bayesian LCMs. Every patient was evaluated for the presence of an eschar and tested with a blood culture for Orientia tsutsugamushi, three different PCR assays, and an IgM IFA. The IgM ELISA was performed for every sample at sample dilutions from 1:100 to 1:102,400 using crude whole-cell antigens of the Karp, Kato, and Gilliam strains of O. tsutsugamushi developed by the Naval Medical Research Center. We used Bayesian LCMs to generate unbiased receiver operating characteristic curves and found that the sample dilution of 1:400 was optimal for the IgM ELISA. With the optimal cutoff OD of 1.474 at a sample dilution of 1:400, the IgM ELISA had a sensitivity of 85.7% (95% credible interval [CrI], 77.4% to 86.7%) and a specificity of 98.1% (95% CrI, 97.2% to 100%) using paired samples. For the ELISA, the OD could be determined objectively and quickly, in contrast to the reading of IFA slides, which was both subjective and labor-intensive. The IgM ELISA for scrub typhus has high diagnostic accuracy and is less subjective than the IgM IFA. We suggest that the IgM ELISA may be used as an alternative reference test to the IgM IFA for the serological diagnosis of scrub typhus.

Aia P, Kal M, Lavu E, John LN, Johnson K, Coulter C, Ershova J, Tosas O, Zignol M, Ahmadova S, Islam T. 2016. The Burden of Drug-Resistant Tuberculosis in Papua New Guinea: Results of a Large Population-Based Survey PLOS ONE, 11 (3), pp. e0149806-e0149806. | Read more

Rachlin A, Dittrich S, Phommasone K, Douangnouvong A, Phetsouvanh R, Newton PN, Dance DAB. 2016. Investigation of Recurrent Melioidosis in Lao People's Democratic Republic by Multilocus Sequence Typing. Am J Trop Med Hyg, 94 (6), pp. 1208-1211. | Citations: 1 (Web of Science Lite) | Show Abstract | Read more

Melioidosis is an infectious disease caused by the saprophytic bacterium Burkholderia pseudomallei In northeast Thailand and northern Australia, where the disease is highly endemic, a range of molecular tools have been used to study its epidemiology and pathogenesis. In the Lao People's Democratic Republic (Laos) where melioidosis has been recognized as endemic since 1999, no such studies have been undertaken. We used a multilocus sequence typing scheme specific for B. pseudomallei to investigate nine cases of culture-positive recurrence occurring in 514 patients with melioidosis between 2010 and 2015: four were suspected to be relapses while the other five represented reinfections. In addition, two novel sequence types of the bacterium were identified. The low overall recurrence rates (2.4%) and proportions of relapse and reinfection in the Laos are consistent with those described in the recent literature, reflecting the effective use of appropriate antimicrobial therapy.

Wei Y, Kypraios T, O'Neill PD, Huang SS, Rifas-Shiman SL, Cooper BS. 2016. Evaluating hospital infection control measures for antimicrobial-resistant pathogens using stochastic transmission models: Application to vancomycin-resistant enterococci in intensive care units. Stat Methods Med Res, pp. 096228021562729-096228021562729. | Show Abstract | Read more

Nosocomial pathogens such as methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococci (VRE) are the cause of significant morbidity and mortality among hospital patients. It is important to be able to assess the efficacy of control measures using data on patient outcomes. In this paper, we describe methods for analysing such data using patient-level stochastic models which seek to describe the underlying unobserved process of transmission. The methods are applied to detailed longitudinal patient-level data on vancomycin-resistant Enterococci from a study in a US hospital with eight intensive care units (ICUs). The data comprise admission and discharge dates, dates and results of screening tests, and dates during which precautionary measures were in place for each patient during the study period. Results include estimates of the efficacy of the control measures, the proportion of unobserved patients colonized with vancomycin-resistant Enterococci, and the proportion of patients colonized on admission.

Park SE, Pak GD, Aaby P, Adu-Sarkodie Y, Ali M, Aseffa A, Biggs HM, Bjerregaard-Andersen M, Breiman RF, Crump JA et al. 2016. The Relationship Between Invasive Nontyphoidal Salmonella Disease, Other Bacterial Bloodstream Infections, and Malaria in Sub-Saharan Africa. Clin Infect Dis, 62 Suppl 1 (suppl 1), pp. S23-S31. | Citations: 7 (Scopus) | Show Abstract | Read more

BACKGROUND: Country-specific studies in Africa have indicated that Plasmodium falciparum is associated with invasive nontyphoidal Salmonella (iNTS) disease. We conducted a multicenter study in 13 sites in Burkina Faso, Ethiopia, Ghana, Guinea-Bissau, Kenya, Madagascar, Senegal, South Africa, Sudan, and Tanzania to investigate the relationship between the occurrence of iNTS disease, other systemic bacterial infections, and malaria. METHODS: Febrile patients received a blood culture and a malaria test. Isolated bacteria underwent antimicrobial susceptibility testing, and the association between iNTS disease and malaria was assessed. RESULTS: A positive correlation between frequency proportions of malaria and iNTS was observed (P = .01; r = 0.70). Areas with higher burden of malaria exhibited higher odds of iNTS disease compared to other bacterial infections (odds ratio [OR], 4.89; 95% CI, 1.61-14.90; P = .005) than areas with lower malaria burden. Malaria parasite positivity was associated with iNTS disease (OR, 2.44; P = .031) and gram-positive bacteremias, particularly Staphylococcus aureus, exhibited a high proportion of coinfection with Plasmodium malaria. Salmonella Typhimurium and Salmonella Enteritidis were the predominant NTS serovars (53/73; 73%). Both moderate (OR, 6.05; P = .0001) and severe (OR, 14.62; P < .0001) anemia were associated with iNTS disease. CONCLUSIONS: A positive correlation between iNTS disease and malaria endemicity, and the association between Plasmodium parasite positivity and iNTS disease across sub-Saharan Africa, indicates the necessity to consider iNTS as a major cause of febrile illness in malaria-holoendemic areas. Prevention of iNTS disease through iNTS vaccines for areas of high malaria endemicity, targeting high-risk groups for Plasmodium parasitic infection, should be considered.

von Kalckreuth V, Konings F, Aaby P, Adu-Sarkodie Y, Ali M, Aseffa A, Baker S, Breiman RF, Bjerregaard-Andersen M, Clemens JD et al. 2016. The Typhoid Fever Surveillance in Africa Program (TSAP): Clinical, Diagnostic, and Epidemiological Methodologies. Clin Infect Dis, 62 Suppl 1 (suppl 1), pp. S9-S16. | Citations: 19 (Scopus) | Show Abstract | Read more

BACKGROUND: New immunization programs are dependent on data from surveillance networks and disease burden estimates to prioritize target areas and risk groups. Data regarding invasive Salmonella disease in sub-Saharan Africa are currently limited, thus hindering the implementation of preventive measures. The Typhoid Fever Surveillance in Africa Program (TSAP) was established by the International Vaccine Institute to obtain comparable incidence data on typhoid fever and invasive nontyphoidal Salmonella (iNTS) disease in sub-Saharan Africa through standardized surveillance in multiple countries. METHODS: Standardized procedures were developed and deployed across sites for study site selection, patient enrolment, laboratory procedures, quality control and quality assurance, assessment of healthcare utilization and incidence calculations. RESULTS: Passive surveillance for bloodstream infections among febrile patients was initiated at thirteen sentinel sites in ten countries (Burkina Faso, Ethiopia, Ghana, Guinea-Bissau, Kenya, Madagascar, Senegal, South Africa, Sudan, and Tanzania). Each TSAP site conducted case detection using these standardized methods to isolate and identify aerobic bacteria from the bloodstream of febrile patients. Healthcare utilization surveys were conducted to adjust population denominators in incidence calculations for differing healthcare utilization patterns and improve comparability of incidence rates across sites. CONCLUSIONS: By providing standardized data on the incidence of typhoid fever and iNTS disease in sub-Saharan Africa, TSAP will provide vital input for targeted typhoid fever prevention programs.

Marks F, Rabehanta N, Baker S, Panzner U, Park SE, Fobil JN, Meyer CG, Rakotozandrindrainy R. 2016. A Way Forward for Healthcare in Madagascar? Clin Infect Dis, 62 Suppl 1 (suppl 1), pp. S76-S79. | Citations: 2 (Scopus) | Show Abstract | Read more

A healthcare utilization survey was conducted as a component of the Typhoid Fever Surveillance in Africa Program (TSAP). The findings of this survey in Madagascar contrasted with those in other sites of the program; namely, only 30% of the population sought healthcare at the government-provided healthcare facilities for fever. These findings promoted us to determine the drivers and barriers in accessing and utilizing healthcare in Madagascar. Here we review the results of the TSAP healthcare utilization initiative and place them in the context of the current organization of the Madagascan healthcare system. Our work highlights the demands of the population for access to appropriate healthcare and the need for novel solutions that can quickly provide an affordable and sustainable basic healthcare infrastructure until a government-funded scheme is in place.

Pach A, Warren M, Chang I, Im J, Nichols C, Meyer CG, Pak GD, Panzner U, Park SE, von Kalckreuth V et al. 2016. A Qualitative Study Investigating Experiences, Perceptions, and Healthcare System Performance in Relation to the Surveillance of Typhoid Fever in Madagascar. Clin Infect Dis, 62 Suppl 1 (suppl 1), pp. S69-S75. | Citations: 2 (Scopus) | Show Abstract | Read more

BACKGROUND: The burden of typhoid fever (TF) in sub-Saharan Africa is largely unknown but is increasingly thought to be high, given that water and sanitary conditions remain unimproved in many countries. To address this gap in information, the Typhoid Fever Surveillance in Africa Program (TSAP) founded a surveillance system for TF in 10 African countries. This study was a component of the TSAP surveillance project in Madagascar. METHODS: The study entailed a qualitative assessment of patients' experiences and perceptions of services for febrile symptoms at the studies' rural and urban sentinel public health clinics. The study examined influences on the use of these facilities, alternative sources of care, and providers' descriptions of medical consultations and challenges in providing services. Data were collected through semistructured and open-ended individual interviews and a focus group with patients, caregivers, and medical personnel. RESULTS: Thirty-three patients and 12 healthcare providers participated in the data collection across the 2 healthcare facilities. The quality of services, cost, and travel distance were key factors that enabled access to and use of these clinics. Divergent healthcare-seeking patterns were related to variability in the care utilized, socioeconomic status, and potential distance from the facilities : These factors influenced delivery of care, patient access, and the health facilities' capacity to identify cases of febrile illness such as TF. CONCLUSIONS: This approach provided an in-depth investigation and understanding of healthcare-seeking behavior at the study facilities, and factors that facilitated or acted as barriers to their use. Our findings demonstrate the relevance of these public health clinics as sites for the surveillance of TF in their role as central healthcare sources for families and communities within these rural and urban areas of Madagascar.

Panzner U, Pak GD, Aaby P, Adu-Sarkodie Y, Ali M, Aseffa A, Baker S, Bjerregaard-Andersen M, Crump JA, Deerin J et al. 2016. Utilization of Healthcare in the Typhoid Fever Surveillance in Africa Program. Clin Infect Dis, 62 Suppl 1 (suppl 1), pp. S56-S68. | Citations: 8 (Scopus) | Show Abstract | Read more

BACKGROUND: Assessing healthcare utilization is important to identify weaknesses of healthcare systems, to outline action points for preventive measures and interventions, and to more accurately estimate the disease burden in a population. METHODS: A healthcare utilization survey was developed for the Typhoid Fever Surveillance in Africa Program (TSAP) to adjust incidences of salmonellosis determined through passive, healthcare facility-based surveillance. This cross-sectional survey was conducted at 11 sites in 9 sub-Saharan African countries. Demographic data and healthcare-seeking behavior were assessed at selected households. Overall and age-stratified percentages of each study population that sought healthcare at a TSAP healthcare facility and elsewhere were determined. RESULTS: Overall, 88% (1007/1145) and 81% (1811/2238) of the population in Polesgo and Nioko 2, Burkina Faso, respectively, and 63% (1636/2590) in Butajira, Ethiopia, sought healthcare for fever at any TSAP healthcare facility. A far smaller proportion-namely, 20%-45% of the population in Bissau, Guinea-Bissau (1743/3885), Pikine, Senegal (1473/4659), Wad-Medani, Sudan (861/3169), and Pietermaritzburg, South Africa (667/2819); 18% (483/2622) and 9% (197/2293) in Imerintsiatosika and Isotry, Madagascar, respectively; and 4% (127/3089) in Moshi, Tanzania-sought healthcare at a TSAP healthcare facility. Patients with fever preferred to visit pharmacies in Imerintsiatosika and Isotry, and favored self-management of fever in Moshi. Age-dependent differences in healthcare utilization were also observed within and across sites. CONCLUSIONS: Healthcare utilization for fever varied greatly across sites, and revealed that not all studied populations were under optimal surveillance. This demonstrates the importance of assessing healthcare utilization. Survey data were pivotal for the adjustment of the program's estimates of salmonellosis and other conditions associated with fever.

Im J, Nichols C, Bjerregaard-Andersen M, Sow AG, Løfberg S, Tall A, Pak GD, Aaby P, Baker S, Clemens JD et al. 2016. Prevalence of Salmonella Excretion in Stool: A Community Survey in 2 Sites, Guinea-Bissau and Senegal. Clin Infect Dis, 62 Suppl 1 (suppl 1), pp. S50-S55. | Citations: 3 (Scopus) | Show Abstract | Read more

BACKGROUND: Chronic and convalescent carriers play an important role in the transmission and endemicity of many communicable diseases. A high incidence of Salmonella enterica serovar Typhi and invasive nontyphoidal Salmonella (NTS) infection has been reported in parts of sub-Saharan Africa, yet the prevalence of Salmonella excretion in the general population is unknown. METHODS: Stool specimens were collected from a random sample of households in 2 populations in West Africa: Bissau, Guinea-Bissau, and Dakar, Senegal. Stool was cultured to detect presence of Salmonella, and antimicrobial susceptibility testing was performed on the isolated organisms. RESULTS: Stool was cultured from 1077 and 1359 individuals from Guinea-Bissau and Senegal, respectively. Salmonella Typhi was not isolated from stool samples at either site. Prevalence of NTS in stool samples was 24.1 (95% confidence interval [CI], 16.5-35.1; n = 26/1077) per 1000 population in Guinea-Bissau and 10.3 (95% CI, 6.1-17.2; n = 14/1359) per 1000 population in Senegal. CONCLUSIONS: Evidence of NTS excretion in stool in both study populations indicates a possible NTS transmission route in these settings.

Al-Emran HM, Eibach D, Krumkamp R, Ali M, Baker S, Biggs HM, Bjerregaard-Andersen M, Breiman RF, Clemens JD, Crump JA et al. 2016. A Multicountry Molecular Analysis of Salmonella enterica Serovar Typhi With Reduced Susceptibility to Ciprofloxacin in Sub-Saharan Africa. Clin Infect Dis, 62 Suppl 1 (suppl 1), pp. S42-S46. | Citations: 5 (Scopus) | Show Abstract | Read more

BACKGROUND: Salmonella enterica serovar Typhi is a predominant cause of bloodstream infections in sub-Saharan Africa (SSA). Increasing numbers of S. Typhi with resistance to ciprofloxacin have been reported from different parts of the world. However, data from SSA are limited. In this study, we aimed to measure the ciprofloxacin susceptibility of S. Typhi isolated from patients with febrile illness in SSA. METHODS: Febrile patients from 9 sites within 6 countries in SSA with a body temperature of ≥38.0°C were enrolled in this study. Blood samples were obtained for bacterial culture, and Salmonella isolates were identified biochemically and confirmed by multiplex polymerase chain reaction (PCR). Antimicrobial susceptibility of all Salmonella isolates was performed by disk diffusion test, and minimum inhibitory concentrations (MICs) against ciprofloxacin were measured by Etest. All Salmonella isolates with reduced susceptibility to ciprofloxacin (MIC > 0.06 µg/mL) were screened for mutations in quinolone resistance-determining regions in target genes, and the presence of plasmid-mediated quinolone resistance (PMQR) genes was assessed by PCR. RESULTS: A total of 8161 blood cultures were performed, and 100 (1.2%) S. Typhi, 2 (<0.1%) Salmonella enterica serovar Paratyphi A, and 27 (0.3%) nontyphoid Salmonella (NTS) were isolated. Multidrug-resistant S. Typhi were isolated in Kenya (79% [n = 38]) and Tanzania (89% [n = 8]) only. Reduced ciprofloxacin-susceptible (22% [n = 11]) S. Typhi were isolated only in Kenya. Among those 11 isolates, all had a Glu133Gly mutation in the gyrA gene combined with either a gyrA (Ser83Phe) or gyrB mutation (Ser464Phe). One Salmonella Paratyphi A isolate with reduced susceptibility to ciprofloxacin was found in Senegal, with 1 mutation in gyrA (Ser83Phe) and a second mutation in parC (Ser57Phe). Mutations in the parE gene and PMQR genes were not detected in any isolate. CONCLUSIONS: Salmonella Typhi with reduced susceptibility to ciprofloxacin was not distributed homogenously throughout SSA. Its prevalence was very high in Kenya, and was not observed in other study countries. Continuous monitoring of antimicrobial susceptibility is required to follow the potential spread of antimicrobial-resistant isolates throughout SSA.

Cruz Espinoza LM, Nichols C, Adu-Sarkodie Y, Al-Emran HM, Baker S, Clemens JD, Dekker DM, Eibach D, Krumkamp R, Boahen K et al. 2016. Variations of Invasive Salmonella Infections by Population Size in Asante Akim North Municipal, Ghana. Clin Infect Dis, 62 Suppl 1 (suppl 1), pp. S17-S22. | Citations: 5 (Scopus) | Show Abstract | Read more

BACKGROUND: The Typhoid Fever Surveillance in Africa Program (TSAP) estimated adjusted incidence rates (IRs) for Salmonella enterica serovar Typhi and invasive nontyphoidal S. enterica serovars (iNTS) of >100 cases per 100 000 person-years of observation (PYO) for children aged <15 years in Asante Akim North Municipal (AAN), Ghana, between March 2010 and May 2012. We analyzed how much these rates differed between rural and urban settings. METHODS: Children recruited at the Agogo Presbyterian Hospital and meeting TSAP inclusion criteria were included in the analysis. Towns with >32 000 inhabitants were considered urban; towns with populations <5200 were considered rural. Adjusted IRs for Salmonella bloodstream infections were estimated for both settings. Setting-specific age-standardized incidence rates for children aged <15 years were derived and used to calculate age-standardized rate ratios (SRRs) to evaluate differences between settings. RESULTS: Eighty-eight percent (2651/3000) of recruited patients met inclusion criteria and were analyzed. IRs of Salmonella bloodstream infections in children <15 years old were >100 per 100 000 PYO in both settings. Among rural children, the Salmonella Typhi and iNTS rates were 2 times (SRR, 2.2; 95% confidence interval [CI], 1.3-3.5) and almost 3 times (SRR, 2.8; 95% CI, 1.9-4.3) higher, respectively, than rates in urban children. CONCLUSIONS: IRs of Salmonella bloodstream infections in children <15 years old in AAN, Ghana, differed by setting, with 2 to nearly 3 times higher rates in the less populated setting. Variations in the distribution of the disease should be considered to implement future studies and intervention strategies.

Baker S, Hombach J, Marks F. 2016. What Have We Learned From the Typhoid Fever Surveillance in Africa Program? Clin Infect Dis, 62 Suppl 1 (suppl 1), pp. S1-S3. | Citations: 5 (Web of Science Lite) | Show Abstract | Read more

The Typhoid Fever Surveillance in Africa Program (TSAP) was established in 2009 to fill the data void concerning invasive Salmonella disease in sub-Saharan Africa, and to specifically estimate the burden of bloodstream infections caused by the key pathogen, Salmonella enterica serovar Typhi. TSAP has achieved this ambitious target, finding high incidences of typhoid fever in both rural and urban populations in several countries in sub-Saharan Africa. The results of TSAP will undoubtedly dictate the direction of future typhoid fever research in Africa, and at last provides a key piece of the disease burden jigsaw puzzle. With the dawn of new Vi conjugate vaccines against Salmonella Typhi, the next priority for the typhoid community must be providing the required data on these vaccines so they can be licensed and provided to those in high-risk groups and locations across sub-Saharan Africa.

Tarning J. 2016. Treatment of Malaria in Pregnancy. N Engl J Med, 374 (10), pp. 981-982. | Citations: 5 (Scopus) | Read more

Bahr NC, Marais S, Caws M, van Crevel R, Wilkinson RJ, Tyagi JS, Thwaites GE, Boulware DR, Tuberculous Meningitis International Research Consortium. 2016. GeneXpert MTB/Rif to Diagnose Tuberculous Meningitis: Perhaps the First Test but not the Last. Clin Infect Dis, 62 (9), pp. 1133-1135. | Citations: 15 (Scopus) | Show Abstract | Read more

Tuberculous meningitis (TBM) is the most severe form of tuberculous with substantial mortality. In May 2015, 54 researchers from 10 countries met in Da Lat, Vietnam, to discuss advances in TBM. Among the attendees were researchers involved in pivotal studies on the use of Xpert MTB/Rif for TBM diagnosis. Attendees discussed the 2014 World Health Organization strong recommendation favoring the use of Xpert "in preference to conventional microscopy and culture as the initial diagnostic test for cerebrospinal fluid (CSF) if the sample volume is low or if additional specimens cannot be obtained to make a quick diagnosis." Attendees were concerned that the limitations of Xpert testing for TBM are not emphasized. Clear guidance is needed for the investigational pathway for TBM, including recommendations on the diagnostic package of investigations, which does not stop with Xpert testing. Second, emphasis on the large CSF volumes (ideally 8-10 mL) needed for Xpert testing is required. Guidelines should also emphasize that TBM is a medical emergency and early treatment reduces mortality.

Sheppard AE, Vaughan A, Jones N, Turner P, Turner C, Efstratiou A, Patel D, Modernising Medical Microbiology Informatics Group, Walker AS, Berkley JA et al. 2016. Capsular Typing Method for Streptococcus agalactiae Using Whole-Genome Sequence Data. J Clin Microbiol, 54 (5), pp. 1388-1390. | Citations: 7 (Web of Science Lite) | Show Abstract | Read more

Group B streptococcus (GBS) capsular serotypes are major determinants of virulence and affect potential vaccine coverage. Here we report a whole-genome-sequencing-based method for GBS serotype assignment. This method shows strong agreement (kappa of 0.92) with conventional methods and increased serotype assignment (100%) to all 10 capsular types.

Boudhar A, Ng XW, Loh CY, Chia WN, Tan ZM, Nosten F, Dymock BW, Tan KSW. 2016. Overcoming Chloroquine Resistance in Malaria: Design, Synthesis, and Structure-Activity Relationships of Novel Hybrid Compounds. Antimicrob Agents Chemother, 60 (5), pp. 3076-3089. | Citations: 3 (Web of Science Lite) | Show Abstract | Read more

Resistance to antimalarial therapies, including artemisinin, has emerged as a significant challenge. Reversal of acquired resistance can be achieved using agents that resensitize resistant parasites to a previously efficacious therapy. Building on our initial work describing novel chemoreversal agents (CRAs) that resensitize resistant parasites to chloroquine (CQ), we herein report new hybrid single agents as an innovative strategy in the battle against resistant malaria. Synthetically linking a CRA scaffold to chloroquine produces hybrid compounds with restored potency toward a range of resistant malaria parasites. A preferred compound, compound 35, showed broad activity and good potency against seven strains resistant to chloroquine and artemisinin. Assessment of aqueous solubility, membrane permeability, and in vitro toxicity in a hepatocyte line and a cardiomyocyte line indicates that compound 35 has a good therapeutic window and favorable drug-like properties. This study provides initial support for CQ-CRA hybrid compounds as a potential treatment for resistant malaria.

Ishioka H, Ghose A, Charunwatthana P, Maude R, Plewes K, Kingston H, Intharabut B, Woodrow C, Chotivanich K, Sayeed AA et al. 2016. Sequestration and Red Cell Deformability as Determinants of Hyperlactatemia in Falciparum Malaria. J Infect Dis, 213 (5), pp. 788-793. | Citations: 2 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Hyperlactatemia is a strong predictor of mortality in severe falciparum malaria. Sequestered parasitized erythrocytes and reduced uninfected red blood cell deformability (RCD) compromise microcirculatory flow, leading to anaerobic glycolysis. METHODS: In a cohort of patients with falciparum malaria hospitalized in Chittagong, Bangladesh, bulk RCD was measured using a laser diffraction technique, and parasite biomass was estimated from plasma concentrations of Plasmodium falciparum histidine-rich protein 2 (PfHRP2). A multiple linear regression model was constructed to examine their associations with plasma lactate concentrations. RESULTS: A total of 286 patients with falciparum malaria were studied, of whom 224 had severe malaria, and 70 died. Hyperlactatemia (lactate level, ≥ 4 mmol/L) was present in 111 cases. RCD at shear stresses of 1.7 Pa and 30 Pa was reduced significantly in patients who died, compared with survivors, individuals with uncomplicated malaria, or healthy individuals (P < .05, for all comparisons). Multiple linear regression analysis showed that the plasma PfHRP2 level, parasitemia level, total bilirubin level, and RCD at a shear stress of 1.7 Pa were each independently correlated with plasma lactate concentrations (n = 278; R(2) = 0.35). CONCLUSIONS: Sequestration of parasitized red blood cells and reduced RCD both contribute to decreased microcirculatory flow in severe disease.

Keyler DE, Richards DP, Warrell DA, Weinstein SA. 2016. Local envenomation from the bite of a juvenile false water cobra (Hydrodynastes gigas; Dipsadidae). Toxicon, 111 pp. 58-61. | Citations: 1 (Scopus) | Show Abstract | Read more

The false water cobra (Hydrodynastes gigas) is a non-front-fanged colubroid snake frequently exhibited in zoos, and maintained by amateur collectors. Little detailed documentation regarding the time-course of symptoms development and the consequences of their bites to humans has been published. Reported here is a case of envenoming in a 25 yo male that occurred after the bite of a juvenile H. gigas. The victim was bitten on the fourth digit of the left hand while processing the snake for sex determination, and the snake remained attached to the digit for approximately 30 s; there was no jaw advancement. Within 5 min, intense local pain developed, and at 4hr post bite the entire dorsal aspect of the hand was significantly edematous, The local effects progressed and involved the entire forearm, and the local pain referred to the axillary region. Mild paresthesia and local blanching ("pallor") were noted in the affected digit, but resolved within 7 days. The clinical course in the patient showed that moderate localized symptoms may result from the bite of a juvenile H.gigas.

Croucher NJ, Mostowy R, Wymant C, Turner P, Bentley SD, Fraser C. 2016. Horizontal DNA Transfer Mechanisms of Bacteria as Weapons of Intragenomic Conflict. PLoS Biol, 14 (3), pp. e1002394. | Citations: 30 (Web of Science Lite) | Show Abstract | Read more

Horizontal DNA transfer (HDT) is a pervasive mechanism of diversification in many microbial species, but its primary evolutionary role remains controversial. Much recent research has emphasised the adaptive benefit of acquiring novel DNA, but here we argue instead that intragenomic conflict provides a coherent framework for understanding the evolutionary origins of HDT. To test this hypothesis, we developed a mathematical model of a clonally descended bacterial population undergoing HDT through transmission of mobile genetic elements (MGEs) and genetic transformation. Including the known bias of transformation toward the acquisition of shorter alleles into the model suggested it could be an effective means of counteracting the spread of MGEs. Both constitutive and transient competence for transformation were found to provide an effective defence against parasitic MGEs; transient competence could also be effective at permitting the selective spread of MGEs conferring a benefit on their host bacterium. The coordination of transient competence with cell-cell killing, observed in multiple species, was found to result in synergistic blocking of MGE transmission through releasing genomic DNA for homologous recombination while simultaneously reducing horizontal MGE spread by lowering the local cell density. To evaluate the feasibility of the functions suggested by the modelling analysis, we analysed genomic data from longitudinal sampling of individuals carrying Streptococcus pneumoniae. This revealed the frequent within-host coexistence of clonally descended cells that differed in their MGE infection status, a necessary condition for the proposed mechanism to operate. Additionally, we found multiple examples of MGEs inhibiting transformation through integrative disruption of genes encoding the competence machinery across many species, providing evidence of an ongoing "arms race." Reduced rates of transformation have also been observed in cells infected by MGEs that reduce the concentration of extracellular DNA through secretion of DNases. Simulations predicted that either mechanism of limiting transformation would benefit individual MGEs, but also that this tactic's effectiveness was limited by competition with other MGEs coinfecting the same cell. A further observed behaviour we hypothesised to reduce elimination by transformation was MGE activation when cells become competent. Our model predicted that this response was effective at counteracting transformation independently of competing MGEs. Therefore, this framework is able to explain both common properties of MGEs, and the seemingly paradoxical bacterial behaviours of transformation and cell-cell killing within clonally related populations, as the consequences of intragenomic conflict between self-replicating chromosomes and parasitic MGEs. The antagonistic nature of the different mechanisms of HDT over short timescales means their contribution to bacterial evolution is likely to be substantially greater than previously appreciated.

Amaratunga C, Lim P, Suon S, Sreng S, Mao S, Sopha C, Sam B, Dek D, Try V, Amato R et al. 2016. Dihydroartemisinin-piperaquine resistance in Plasmodium falciparum malaria in Cambodia: a multisite prospective cohort study. Lancet Infect Dis, 16 (3), pp. 357-365. | Citations: 93 (Scopus) | Show Abstract | Read more

BACKGROUND: Artemisinin resistance in Plasmodium falciparum threatens to reduce the efficacy of artemisinin combination therapies (ACTs), thus compromising global efforts to eliminate malaria. Recent treatment failures with dihydroartemisinin-piperaquine, the current first-line ACT in Cambodia, suggest that piperaquine resistance may be emerging in this country. We explored the relation between artemisinin resistance and dihydroartemisinin-piperaquine failures, and sought to confirm the presence of piperaquine-resistant P falciparum infections in Cambodia. METHODS: In this prospective cohort study, we enrolled patients aged 2-65 years with uncomplicated P falciparum malaria in three Cambodian provinces: Pursat, Preah Vihear, and Ratanakiri. Participants were given standard 3-day courses of dihydroartemisinin-piperaquine. Peripheral blood parasite densities were measured until parasites cleared and then weekly to 63 days. The primary outcome was recrudescent P falciparum parasitaemia within 63 days. We measured piperaquine plasma concentrations at baseline, 7 days, and day of recrudescence. We assessed phenotypic and genotypic markers of drug resistance in parasite isolates. The study is registered with, number NCT01736319. FINDINGS: Between Sept 4, 2012, and Dec 31, 2013, we enrolled 241 participants. In Pursat, where artemisinin resistance is entrenched, 37 (46%) of 81 patients had parasite recrudescence. In Preah Vihear, where artemisinin resistance is emerging, ten (16%) of 63 patients had recrudescence and in Ratanakiri, where artemisinin resistance is rare, one (2%) of 60 patients did. Patients with recrudescent P falciparum infections were more likely to have detectable piperaquine plasma concentrations at baseline compared with non-recrudescent patients, but did not differ significantly in age, initial parasite density, or piperaquine plasma concentrations at 7 days. Recrudescent parasites had a higher prevalence of kelch13 mutations, higher piperaquine 50% inhibitory concentration (IC50) values, and lower mefloquine IC50 values; none had multiple pfmdr1 copies, a genetic marker of mefloquine resistance. INTERPRETATION: Dihydroartemisinin-piperaquine failures are caused by both artemisinin and piperaquine resistance, and commonly occur in places where dihydroartemisinin-piperaquine has been used in the private sector. In Cambodia, artesunate plus mefloquine may be a viable option to treat dihydroartemisinin-piperaquine failures, and a more effective first-line ACT in areas where dihydroartemisinin-piperaquine failures are common. The use of single low-dose primaquine to eliminate circulating gametocytes is needed in areas where artemisinin and ACT resistance is prevalent. FUNDING: National Institute of Allergy and Infectious Diseases.

Bharucha T, Chanthongthip A, Phuangpanom S, Phonemixay O, Sengvilaipaseuth O, Vongsouvath M, Lee S, Newton PN, Dubot-Pérès A. 2016. Pre-cut Filter Paper for Detecting Anti-Japanese Encephalitis Virus IgM from Dried Cerebrospinal Fluid Spots. PLoS Negl Trop Dis, 10 (3), pp. e0004516. | Citations: 1 (Scopus) | Show Abstract | Read more

BACKGROUND: The use of filter paper as a simple, inexpensive tool for storage and transportation of blood, 'Dried Blood Spots' or Guthrie cards, for diagnostic assays is well-established. In contrast, there are a paucity of diagnostic evaluations of dried cerebrospinal fluid (CSF) spots. These have potential applications in low-resource settings, such as Laos, where laboratory facilities for central nervous system (CNS) diagnostics are only available in Vientiane. In Laos, a major cause of CNS infection is Japanese encephalitis virus (JEV). We aimed to develop a dried CSF spot protocol and to evaluate its diagnostic performance using the World Health Organisation recommended anti-JEV IgM antibody capture enzyme-linked immunosorbent assay (JEV MAC-ELISA). METHODOLOGY AND PRINCIPAL FINDINGS: Sample volumes, spotting techniques and filter paper type were evaluated using a CSF-substitute of anti-JEV IgM positive serum diluted in Phosphate Buffer Solution (PBS) to end-limits of detection by JEV MAC-ELISA. A conventional protocol, involving eluting one paper punch in 200 μl PBS, did not detect the end-dilution, nor did multiple punches utilising diverse spotting techniques. However, pre-cut filter paper enabled saturation with five times the volume of CSF-substitute, sufficiently improving sensitivity to detect the end-dilution. The diagnostic accuracy of this optimised protocol was compared with routine, neat CSF in a pilot, retrospective study of JEV MAC-ELISA on consecutive CSF samples, collected 2009-15, from three Lao hospitals. In comparison to neat CSF, 132 CSF samples stored as dried CSF spots for one month at 25-30 °C showed 81.6% (65.7-92.3 95%CI) positive agreement, 96.8% (91.0-99.3 95%CI) negative agreement, with a kappa coefficient of 0.81 (0.70-0.92 95%CI). CONCLUSIONS/SIGNIFICANCE: The novel design of pre-cut filter paper saturated with CSF could provide a useful tool for JEV diagnostics in settings with limited laboratory access. It has the potential to improve national JEV surveillance and inform vaccination policies. The saturation of filter paper has potential use in the wider context of pathogen detection, including dried spots for detecting other analytes in CSF, and other body fluids.

Boni MF, White NJ, Baird JK. 2016. The Community As the Patient in Malaria-Endemic Areas: Preempting Drug Resistance with Multiple First-Line Therapies. PLoS Med, 13 (3), pp. e1001984. | Citations: 9 (Scopus) | Show Abstract | Read more

Maciej F. Boni and colleagues propose deploying multiple first-line combination therapies against malaria within a community to delay drug-resistance evolution.

Hamza M, Idris MA, Maiyaki MB, Lamorde M, Chippaux J-P, Warrell DA, Kuznik A, Habib AG. 2016. Cost-Effectiveness of Antivenoms for Snakebite Envenoming in 16 Countries in West Africa. PLoS Negl Trop Dis, 10 (3), pp. e0004568. | Citations: 1 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Snakebite poisoning is a significant medical problem in agricultural societies in Sub Saharan Africa. Antivenom (AV) is the standard treatment, and we assessed the cost-effectiveness of making it available in 16 countries in West Africa. METHODS: We determined the cost-effectiveness of AV based on a decision-tree model from a public payer perspective. Specific AVs included in the model were Antivipmyn, FAV Afrique, EchiTab-G and EchiTab-Plus. We derived inputs from the literature which included: type of snakes causing bites (carpet viper (Echis species)/non-carpet viper), AV effectiveness against death, mortality without AV, probability of Early Adverse Reactions (EAR), likelihood of death from EAR, average age at envenomation in years, anticipated remaining life span and likelihood of amputation. Costs incurred by the victims include: costs of confirming and evaluating envenomation, AV acquisition, routine care, AV transportation logistics, hospital admission and related transportation costs, management of AV EAR compared to the alternative of free snakebite care with ineffective or no AV. Incremental Cost Effectiveness Ratios (ICERs) were assessed as the cost per death averted and the cost per Disability-Adjusted-Life-Years (DALY) averted. Probabilistic Sensitivity Analyses (PSA) using Monte Carlo simulations were used to obtain 95% Confidence Intervals of ICERs. RESULTS: The cost/death averted for the 16 countries of interest ranged from $1,997 in Guinea Bissau to $6,205 for Liberia and Sierra Leone. The cost/DALY averted ranged from $83 (95% Confidence Interval: $36-$240) for Benin Republic to $281 ($159-457) for Sierra-Leone. In all cases, the base-case cost/DALY averted estimate fell below the commonly accepted threshold of one time per capita GDP, suggesting that AV is highly cost-effective for the treatment of snakebite in all 16 WA countries. The findings were consistent even with variations of inputs in 1-way sensitivity analyses. In addition, the PSA showed that in the majority of iterations ranging from 97.3% in Liberia to 100% in Cameroun, Guinea Bissau, Mali, Nigeria and Senegal, our model results yielded an ICER that fell below the threshold of one time per capita GDP, thus, indicating a high degree of confidence in our results. CONCLUSIONS: Therapy for SBE with AV in countries of WA is highly cost-effective at commonly accepted thresholds. Broadening access to effective AVs in rural communities in West Africa is a priority.

Lafond KE, Nair H, Rasooly MH, Valente F, Booy R, Rahman M, Kitsutani P, Yu H, Guzman G, Coulibaly D et al. 2016. Global Role and Burden of Influenza in Pediatric Respiratory Hospitalizations, 1982-2012: A Systematic Analysis. PLoS Med, 13 (3), pp. e1001977. | Citations: 20 (Scopus) | Show Abstract | Read more

BACKGROUND: The global burden of pediatric severe respiratory illness is substantial, and influenza viruses contribute to this burden. Systematic surveillance and testing for influenza among hospitalized children has expanded globally over the past decade. However, only a fraction of the data has been used to estimate influenza burden. In this analysis, we use surveillance data to provide an estimate of influenza-associated hospitalizations among children worldwide. METHODS AND FINDINGS: We aggregated data from a systematic review (n = 108) and surveillance platforms (n = 37) to calculate a pooled estimate of the proportion of samples collected from children hospitalized with respiratory illnesses and positive for influenza by age group (<6 mo, <1 y, <2 y, <5 y, 5-17 y, and <18 y). We applied this proportion to global estimates of acute lower respiratory infection hospitalizations among children aged <1 y and <5 y, to obtain the number and per capita rate of influenza-associated hospitalizations by geographic region and socio-economic status. Influenza was associated with 10% (95% CI 8%-11%) of respiratory hospitalizations in children <18 y worldwide, ranging from 5% (95% CI 3%-7%) among children <6 mo to 16% (95% CI 14%-20%) among children 5-17 y. On average, we estimated that influenza results in approximately 374,000 (95% CI 264,000 to 539,000) hospitalizations in children <1 y-of which 228,000 (95% CI 150,000 to 344,000) occur in children <6 mo-and 870,000 (95% CI 610,000 to 1,237,000) hospitalizations in children <5 y annually. Influenza-associated hospitalization rates were more than three times higher in developing countries than in industrialized countries (150/100,000 children/year versus 48/100,000). However, differences in hospitalization practices between settings are an important limitation in interpreting these findings. CONCLUSIONS: Influenza is an important contributor to respiratory hospitalizations among young children worldwide. Increasing influenza vaccination coverage among young children and pregnant women could reduce this burden and protect infants <6 mo.

Bharucha T, Chanthongthip A, Phuangpanom S, Phonemixay O, Sengvilaipaseuth O, Vongsouvath M, Lee S, Newton PN, Dubot-Peres A. 2016. Pre-cut Filter Paper for Detecting Anti-Japanese Encephalitis Virus IgM from Dried Cerebrospinal Fluid Spots PLOS NEGLECTED TROPICAL DISEASES, 10 (3), | Citations: 1 (Web of Science Lite) | Read more

Schultz MB, Pham Thanh D, Tran Do Hoan N, Wick RR, Ingle DJ, Hawkey J, Edwards DJ, Kenyon JJ, Phu Huong Lan N, Campbell JI et al. 2016. Repeated local emergence of carbapenem-resistant Acinetobacter baumannii in a single hospital ward. Microb Genom, 2 (3), pp. e000050. | Show Abstract | Read more

We recently reported a dramatic increase in the prevalence of carbapenem-resistant Acinetobacter baumannii infections in the intensive care unit (ICU) of a Vietnamese hospital. This upsurge was associated with a specific oxa23-positive clone that was identified by multilocus VNTR analysis. Here, we used whole-genome sequence analysis to dissect the emergence of carbapenem-resistant A. baumannii causing ventilator-associated pneumonia (VAP) in the ICU during 2009-2012. To provide historical context and distinguish microevolution from strain introduction, we compared these genomes with those of A. baumannii asymptomatic carriage and VAP isolates from this same ICU collected during 2003-2007. We identified diverse lineages co-circulating over many years. Carbapenem resistance was associated with the presence of oxa23, oxa40, oxa58 and ndm1 genes in multiple lineages. The majority of resistant isolates were oxa23-positive global clone GC2; fine-scale phylogenomic analysis revealed five distinct GC2 sublineages within the ICU that had evolved locally via independent chromosomal insertions of oxa23 transposons. The increase in infections caused by carbapenem-resistant A. baumannii was associated with transposon-mediated transmission of a carbapenemase gene, rather than clonal expansion or spread of a carbapenemase-harbouring plasmid. Additionally, we found evidence of homologous recombination creating diversity within the local GC2 population, including several events resulting in replacement of the capsule locus. We identified likely donors of the imported capsule locus sequences amongst the A. baumannii isolated on the same ward, suggesting that diversification was largely facilitated via reassortment and sharing of genetic material within the localized A. baumannii population.

Nosten F. 2016. [Elimination in South-East Asia? The role of antimalarial drugs]. Bull Acad Natl Med, 200 (3), pp. 467-475. | Show Abstract

Artemisinin resistance in P. falciparum is spreading in South East Asia and threatens the recent progresses made in the fight against malaria. A race against time has started to eliminate P.falciparum in this region before it becomes resistant to all available treatments. Antimalarials have a central role in the current elimination programme in eastern Burma on the border with Thailand. The combination of artemether and lumefantrine is used in association with primaquine for the early treatment of clinical cases. The slowly eliminated dihydro-artemisinin and piperaquine is the drug of choice in mass drug administration in the foci of high prevalence of sub-microscopic and asymptomatic infections. Initial results after 18 months of activities are promising: the participation of the population was excellent and there was a sharp reduction of P.falciparum incidence without evidence of worsening resistance.

Nguyen AT, Nghiem N, Tran T, Hoang V, Le N, Phan Q, Le N, Ho V, Do V, Ha T et al. 2016. Development and evaluation of a vral-specific random PCR and next-generation sequencing based assay for detection and sequencing of hand, foot, and mouth disease pathogens INTERNATIONAL JOURNAL OF INFECTIOUS DISEASES, 45 pp. 187-187. | Read more

Hoang VMT, Nguyen TA, Tran TT, Ha MT, Do V, Ho V, Nguyen TH, Huu KT, Le N, Vinh CNV et al. 2016. Clinical features and virology of hand foot mouth disease in Southern Vietnam, July 2013 March 2015 INTERNATIONAL JOURNAL OF INFECTIOUS DISEASES, 45 pp. 20-20. | Read more

Siegrist C, Kaiser L, Tapparel C, van Doorn HR. 2016. Clinical features, cytokine profiles and immune response in children with severe hand foot and mouth disease in Vietnam INTERNATIONAL JOURNAL OF INFECTIOUS DISEASES, 45 pp. 192-193. | Read more

Leang R, Canavati SE, Khim N, Vestergaard LS, Borghini Fuhrer I, Kim S, Denis MB, Heng P, Tol B, Huy R et al. 2016. Efficacy and Safety of Pyronaridine-Artesunate for Treatment of Uncomplicated Plasmodium falciparum Malaria in Western Cambodia. Antimicrob Agents Chemother, 60 (7), pp. 3884-3890. | Citations: 9 (Scopus) | Show Abstract | Read more

Pyronaridine-artesunate efficacy for the treatment of uncomplicated Plasmodium falciparum malaria was assessed in an area of artemisinin resistance in western Cambodia. This nonrandomized, single-arm, observational study was conducted between 2014 and 2015. Eligible patients were adults or children with microscopically confirmed P. falciparum infection and fever. Patients received pyronaridine-artesunate once daily for 3 days, dosed according to body weight. The primary outcome was an adequate clinical and parasitological response (ACPR) on day 42, estimated by using Kaplan-Meier analysis, PCR adjusted to exclude reinfection. One hundred twenty-three patients were enrolled. Day 42 PCR-crude ACPRs were 87.2% (95% confidence interval [CI], 79.7 to 92.6%) for the overall study, 89.8% (95% CI, 78.8 to 95.3%) for Pursat, and 82.1% (95% CI, 68.4 to 90.2%) for Pailin. Day 42 PCR-adjusted ACPRs were 87.9% (95% CI, 80.6 to 93.2%) for the overall study, 89.8% (95% CI, 78.8 to 95.3%) for Pursat, and 84.0% (95% CI, 70.6 to 91.7%) for Pailin (P = 0.353 by a log rank test). Day 28 PCR-crude and -adjusted ACPRs were 93.2% (95% CI, 82.9 to 97.4%) and 88.1% (95% CI, 75.3 to 94.5%) for Pursat and Pailin, respectively. A significantly lower proportion of patients achieved day 3 parasite clearance in Pailin (56.4% [95% CI, 43.9 to 69.6%]) than in Pursat (86.7% [95% CI, 76.8 to 93.8%]; P = 0.0019). Fever clearance was also extended at Pailin versus Pursat (P < 0.0001). Most patients (95.9% [116/121]) harbored P. falciparum kelch13 C580Y mutant parasites. Pyronaridine-artesunate was well tolerated; mild increases in hepatic transaminase levels were consistent with data from previous reports. Pyronaridine-artesunate efficacy was below the World Health Organization-recommended threshold at day 42 for medicines with a long half-life (90%) for first-line treatment of P. falciparum malaria in western Cambodia despite high efficacy elsewhere in Asia and Africa. (This study has been registered at under registration number NCT02389439.).

The HC, Thanh DP, Holt KE, Thomson NR, Baker S. 2016. The genomic signatures of Shigella evolution, adaptation and geographical spread. Nat Rev Microbiol, 14 (4), pp. 235-250. | Citations: 17 (Scopus) | Show Abstract | Read more

Shigella spp. are some of the key pathogens responsible for the global burden of diarrhoeal disease. These facultative intracellular bacteria belong to the family Enterobacteriaceae, together with other intestinal pathogens, such as Escherichia coli and Salmonella spp. The genus Shigella comprises four different species, each consisting of several serogroups, all of which show phenotypic similarity, including invasive pathogenicity. DNA sequencing suggests that this similarity results from the convergent evolution of different Shigella spp. founders. Here, we review the evolutionary relationships between Shigella spp. and E . coli, and we highlight how the genomic plasticity of these bacteria and their acquisition of a distinctive virulence plasmid have enabled the development of such highly specialized pathogens. Furthermore, we discuss the insights that genotyping and whole-genome sequencing have provided into the phylogenetics and intercontinental spread of Shigella spp.

Suttisunhakul V, Wuthiekanun V, Brett PJ, Khusmith S, Day NPJ, Burtnick MN, Limmathurotsakul D, Chantratita N. 2016. Development of Rapid Enzyme-Linked Immunosorbent Assays for Detection of Antibodies to Burkholderia pseudomallei. J Clin Microbiol, 54 (5), pp. 1259-1268. | Citations: 10 (Scopus) | Show Abstract | Read more

Burkholderia pseudomallei, the causative agent of melioidosis, is an environmental bacillus found in northeast Thailand. The mortality rate of melioidosis is ∼40%. An indirect hemagglutination assay (IHA) is used as a reference serodiagnostic test; however, it has low specificity in areas where the background seropositivity of healthy people is high. To improve assay specificity and reduce the time for diagnosis, four rapid enzyme-linked immunosorbent assays (ELISAs) were developed using two purified polysaccharide antigens (O-polysaccharide [OPS] and 6-deoxyheptan capsular polysaccharide [CPS]) and two crude antigens (whole-cell [WC] antigen and culture filtrate [CF] antigen) of B. pseudomallei The ELISAs were evaluated using serum samples from 141 culture-confirmed melioidosis patients from Thailand along with 188 healthy donors from Thailand and 90 healthy donors from the United States as controls. The areas under receiver operator characteristic curves (AUROCC) using Thai controls were high for the OPS-ELISA (0.91), CF-ELISA (0.91), and WC-ELISA (0.90), while those of CPS-ELISA (0.84) and IHA (0.72) were lower. AUROCC values using U.S. controls were comparable to those of the Thai controls for all ELISAs except IHA (0.93). Using a cutoff optical density (OD) of 0.87, the OPS-ELISA had a sensitivity of 71.6% and a specificity of 95.7% for Thai controls; for U.S. controls, specificity was 96.7%. An additional 120 serum samples from tuberculosis, scrub typhus, or leptospirosis patients were evaluated in all ELISAs and resulted in comparable or higher specificities than using Thai healthy donors. Our findings suggest that antigen-specific ELISAs, particularly the OPS-ELISA, may be useful for serodiagnosis of melioidosis in areas where it is endemic and nonendemic.

Turner P, Pol S, Soeng S, Sar P, Neou L, Chea P, Day NPJ, Cooper BS, Turner C. 2016. High Prevalence of Antimicrobial-resistant Gram-negative Colonization in Hospitalized Cambodian Infants PEDIATRIC INFECTIOUS DISEASE JOURNAL, 35 (8), pp. 856-861. | Citations: 2 (Web of Science Lite) | Read more

Dondorp AM, Iyer SS, Schultz MJ. 2016. Critical Care in Resource-Restricted Settings. JAMA, 315 (8), pp. 753-754. | Citations: 9 (Scopus) | Read more

Deeny SR, Worby CJ, Tosas Auguet O, Cooper BS, Edgeworth J, Cookson B, Robotham JV. 2016. More Research Is Needed to Quantify Risks, Benefits, and Cost-Effectiveness of Universal Mupirocin Usage. Clin Infect Dis, 62 (9), pp. 1193-1194. | Citations: 1 (Web of Science Lite) | Read more

Nguyen THM, Thwaites GE. 2016. The current pharmacological landscape of tuberculous meningitis: where to next? Expert Rev Clin Pharmacol, 9 (5), pp. 625-627. | Citations: 2 (Scopus) | Read more

Warimwe GM, Abdi AI, Muthui M, Fegan G, Musyoki JN, Marsh K, Bull PC. 2016. Serological Conservation of Parasite-Infected Erythrocytes Predicts Plasmodium falciparum Erythrocyte Membrane Protein 1 Gene Expression but Not Severity of Childhood Malaria. Infect Immun, 84 (5), pp. 1331-1335. | Citations: 3 (Web of Science Lite) | Show Abstract | Read more

Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1), expressed on P. falciparum-infected erythrocytes, is a major family of clonally variant targets of naturally acquired immunity to malaria. Previous studies have demonstrated that in areas where malaria is endemic, antibodies to infected erythrocytes from children with severe malaria tend to be more seroprevalent than antibodies to infected erythrocytes from children with nonsevere malaria. These data have led to a working hypothesis that PfEMP1 variants associated with parasite virulence are relatively conserved in structure. However, the longevity of such serologically conserved variants in the parasite population is unknown. Here, using infected erythrocytes from recently sampled clinical P. falciparum samples, we measured serological conservation using pools of antibodies in sera that had been sampled 10 to 12 years earlier. The serological conservation of infected erythrocytes strongly correlated with the expression of specific PfEMP1 subsets previously found to be associated with severe malaria. However, we found no association between serological conservation per se and disease severity within these data. This contrasts with the simple hypothesis that P. falciparum isolates with a serologically conserved group of PfEMP1 variants cause severe malaria. The data are instead consistent with periodic turnover of the immunodominant epitopes of PfEMP1 associated with severe malaria.

Hearn P, Turner C, Suy K, Soeng S, Day NPJ, Turner P. 2016. Lack of Utility of Nasopharyngeal Swabs for Diagnosis of Burkholderia pseudomallei Pneumonia in Paediatric Patients. J Trop Pediatr, 62 (4), pp. 328-330. | Show Abstract | Read more

Diagnosis of Burkholderia pseudomallei pneumonia in children is challenging. We investigated the utility of nasopharyngeal swabs taken from 194 paediatric patients on admission with radiologically proven pneumonia. Melioidosis was proven in 0.5% of samples tested and only in a third of those known to be bacteraemic with B. pseudomallei. It appears unlikely that culture of nasopharyngeal secretions is helpful to confirm B. pseudomallei pneumonia in paediatric patients.

Beardsley J, Wolbers M, Kibengo FM, Ggayi A-BM, Kamali A, Cuc NTK, Binh TQ, Chau NVV, Farrar J, Merson L et al. 2016. Adjunctive Dexamethasone in HIV-Associated Cryptococcal Meningitis. N Engl J Med, 374 (6), pp. 542-554. | Citations: 42 (Scopus) | Show Abstract | Read more

BACKGROUND: Cryptococcal meningitis associated with human immunodeficiency virus (HIV) infection causes more than 600,000 deaths each year worldwide. Treatment has changed little in 20 years, and there are no imminent new anticryptococcal agents. The use of adjuvant glucocorticoids reduces mortality among patients with other forms of meningitis in some populations, but their use is untested in patients with cryptococcal meningitis. METHODS: In this double-blind, randomized, placebo-controlled trial, we recruited adult patients with HIV-associated cryptococcal meningitis in Vietnam, Thailand, Indonesia, Laos, Uganda, and Malawi. All the patients received either dexamethasone or placebo for 6 weeks, along with combination antifungal therapy with amphotericin B and fluconazole. RESULTS: The trial was stopped for safety reasons after the enrollment of 451 patients. Mortality was 47% in the dexamethasone group and 41% in the placebo group by 10 weeks (hazard ratio in the dexamethasone group, 1.11; 95% confidence interval [CI], 0.84 to 1.47; P=0.45) and 57% and 49%, respectively, by 6 months (hazard ratio, 1.18; 95% CI, 0.91 to 1.53; P=0.20). The percentage of patients with disability at 10 weeks was higher in the dexamethasone group than in the placebo group, with 13% versus 25% having a prespecified good outcome (odds ratio, 0.42; 95% CI, 0.25 to 0.69; P<0.001). Clinical adverse events were more common in the dexamethasone group than in the placebo group (667 vs. 494 events, P=0.01), with more patients in the dexamethasone group having grade 3 or 4 infection (48 vs. 25 patients, P=0.003), renal events (22 vs. 7, P=0.004), and cardiac events (8 vs. 0, P=0.004). Fungal clearance in cerebrospinal fluid was slower in the dexamethasone group. Results were consistent across Asian and African sites. CONCLUSIONS: Dexamethasone did not reduce mortality among patients with HIV-associated cryptococcal meningitis and was associated with more adverse events and disability than was placebo. (Funded by the United Kingdom Department for International Development and others through the Joint Global Health Trials program; Current Controlled Trials number, ISRCTN59144167.).

Charnaud SC, McGready R, Herten-Crabb A, Powell R, Guy A, Langer C, Richards JS, Gilson PR, Chotivanich K, Tsuboi T et al. 2016. Maternal-foetal transfer of Plasmodium falciparum and Plasmodium vivax antibodies in a low transmission setting. Sci Rep, 6 (1), pp. 20859. | Citations: 2 (Web of Science Lite) | Show Abstract | Read more

During pregnancy immunoglobulin G (IgG) antibodies are transferred from mother to neonate across the placenta. Studies in high transmission areas have shown transfer of P. falciparum-specific IgG, but the extent and factors influencing maternal-foetal transfer in low transmission areas co-endemic for both P. falciparum and P. vivax are unknown. Pregnant women were screened weekly for Plasmodium infection. Mother-neonate paired serum samples at delivery were tested for IgG to antigens from P. falciparum, P. vivax and other infectious diseases. Antibodies to malarial and non-malarial antigens were highly correlated between maternal and neonatal samples (median [range] spearman ρ = 0.78 [0.57-0.93]), although Plasmodium spp. antibodies tended to be lower in neonates than mothers. Estimated gestational age at last P. falciparum infection, but not P. vivax infection, was positively associated with antibody levels in the neonate (P. falciparum merozoite, spearman ρ median [range] 0.42 [0.33-0.66], PfVAR2CSA 0.69; P. vivax ρ = 0.19 [0.09-0.3]). Maternal-foetal transfer of anti-malarial IgG to Plasmodium spp. antigens occurs in low transmission settings. P. vivax IgG acquisition is not associated with recent exposure unlike P. falciparum IgG, suggesting a difference in acquisition of antibodies. IgG transfer is greatest in the final weeks of pregnancy which has implications for the timing of future malaria vaccination strategies in pregnant women.

Duong VT, Phat VV, Tuyen HT, Dung TTN, Trung PD, Minh PV, Tu LTP, Campbell JI, Le Phuc H, Ha TTT et al. 2016. Evaluation of Luminex xTAG Gastrointestinal Pathogen Panel Assay for Detection of Multiple Diarrheal Pathogens in Fecal Samples in Vietnam. J Clin Microbiol, 54 (4), pp. 1094-1100. | Citations: 10 (Scopus) | Show Abstract | Read more

Diarrheal disease is a complex syndrome that remains a leading cause of global childhood morbidity and mortality. The diagnosis of enteric pathogens in a timely and precise manner is important for making treatment decisions and informing public health policy, but accurate diagnosis is a major challenge in industrializing countries. Multiplex molecular diagnostic techniques may represent a significant improvement over classical approaches. We evaluated the Luminex xTAG gastrointestinal pathogen panel (GPP) assay for the detection of common enteric bacterial and viral pathogens in Vietnam. Microbiological culture and real-time PCR were used as gold standards. The tests were performed on 479 stool samples collected from people admitted to the hospital for diarrheal disease throughout Vietnam. Sensitivity and specificity were calculated for the xTAG GPP for the seven principal diarrheal etiologies. The sensitivity and specificity for the xTAG GPP were >88% for Shigellaspp.,Campylobacterspp., rotavirus, norovirus genotype 1/2 (GI/GII), and adenovirus compared to those of microbiological culture and/or real-time PCR. However, the specificity was low (∼60%) for Salmonella species. Additionally, a number of important pathogens that are not identified in routine hospital procedures in this setting, such as Cryptosporidiumspp. and Clostridium difficile, were detected with the GPP. The use of the Luminex xTAG GPP for the detection of enteric pathogens in settings, like Vietnam, would dramatically improve the diagnostic accuracy and capacity of hospital laboratories, allowing for timely and appropriate therapy decisions and a wider understanding of the epidemiology of pathogens associated with severe diarrheal disease in low-resource settings.

Van Vinh Chau N, Buu Chau L, Desquesnes M, Herder S, Phu Huong Lan N, Campbell JI, Van Cuong N, Yimming B, Chalermwong P, Jittapalapong S et al. 2016. A Clinical and Epidemiological Investigation of the First Reported Human Infection With the Zoonotic Parasite Trypanosoma evansi in Southeast Asia. Clin Infect Dis, 62 (8), pp. 1002-1008. | Citations: 7 (Scopus) | Show Abstract | Read more

BACKGROUND: Trypanosomais a genus of unicellular parasitic flagellate protozoa.Trypanosoma bruceispecies and Trypanosoma cruziare the major agents of human trypanosomiasis; other Trypanosomaspecies can cause human disease, but are rare. In March 2015, a 38-year-old woman presented to a healthcare facility in southern Vietnam with fever, headache, and arthralgia. Microscopic examination of blood revealed infection with Trypanosoma METHODS: Microscopic observation, polymerase chain reaction (PCR) amplification of blood samples, and serological testing were performed to identify the infecting species. The patient's blood was screened for the trypanocidal protein apolipoprotein L1 (APOL1), and a field investigation was performed to identify the zoonotic source. RESULTS: PCR amplification and serological testing identified the infecting species as Trypanosoma evansi.Despite relapsing 6 weeks after completing amphotericin B therapy, the patient made a complete recovery after 5 weeks of suramin. The patient was found to have 2 wild-type APOL1 alleles and a normal serum APOL1 concentration. After responsive animal sampling in the presumed location of exposure, cattle and/or buffalo were determined to be the most likely source of the infection, with 14 of 30 (47%) animal blood samples testing PCR positive forT. evansi. CONCLUSIONS: We report the first laboratory-confirmed case ofT. evansiin a previously healthy individual without APOL1 deficiency, potentially contracted via a wound while butchering raw beef, and successfully treated with suramin. A linked epidemiological investigation revealed widespread and previously unidentified burden ofT. evansiin local cattle, highlighting the need for surveillance of this infection in animals and the possibility of further human cases.

Hammitt LL, Crane RJ, Karani A, Mutuku A, Morpeth SC, Burbidge P, Goldblatt D, Kamau T, Sharif S, Mturi N, Scott JAG. 2016. Effect of Haemophilus influenzae type b vaccination without a booster dose on invasive H influenzae type b disease, nasopharyngeal carriage, and population immunity in Kilifi, Kenya: a 15-year regional surveillance study. Lancet Glob Health, 4 (3), pp. e185-e194. | Citations: 5 (Scopus) | Show Abstract | Read more

BACKGROUND: Haemophilus influenzae type b (Hib) conjugate vaccine, delivered as a three-dose series without a booster, was introduced into the childhood vaccination programme in Kenya in 2001. The duration of protection and need for a booster dose are unknown. We aimed to assess vaccine effectiveness, the impact of the vaccine on nasopharyngeal carriage, and population immunity after introduction of conjugate Hib vaccine in infancy without a booster dose in Kenya. METHODS: This study took place in the Kilifi Health and Demographic Surveillance System (KHDSS), an area of Kenya that has been monitored for vital events and migration every 4 months since 2000. We analysed sterile site cultures for H influenzae type b from children (aged ≤12 years) admitted to the Kilifi County Hospital (KCH) from Jan 1, 2000, through to Dec 31, 2014. We determined the prevalence of nasopharyngeal carriage by undertaking cross-sectional surveys in random samples of KHDSS residents (of all ages) once every year from 2009 to 2012, and measured Hib antibody concentrations in five cross-sectional samples of children (aged ≤12 years) within the KHDSS (in 1998, 2000, 2004-05, 2007, and 2009). We calculated incidence rate ratios between the prevaccine era (2000-01) and the routine-use era (2004-14) and defined vaccine effectiveness as 1 minus the incidence rate ratio, expressed as a percentage. FINDINGS: 40,482 children younger than 13 years resident in KHDSS were admitted to KCH between 2000 and 2014, 38,206 (94%) of whom had their blood cultured. The incidence of invasive H influenzae type b disease in children younger than 5 years declined from 62·6 (95% CI 46·0-83·3) per 100,000 in 2000-01 to 4·5 (2·5-7·5) per 100,000 in 2004-14, giving a vaccine effectiveness of 93% (95% CI 87-96). In the final 5 years of observation (2010-14), only one case of invasive H influenzae type b disease was detected in a child younger than 5 years. Nasopharyngeal H influenzae type b carriage was detected in one (0·2%) of 623 children younger than 5 years between 2009 and 2012. In the 2009 serosurvey, 92 (79%; 95% CI 70-86) of 117 children aged 4-35 months had long-term protective antibody concentrations. INTERPRETATION: In this region of Kenya, use of a three-dose primary series of Hib vaccine without a booster dose has resulted in a significant and sustained reduction in invasive H influenzae type b disease. The prevalence of nasopharyngeal carriage is low and the profile of Hib antibodies suggests that protection wanes only after the age at greatest risk of disease. Although continued surveillance is important to determine whether effective control persists, these findings suggest that a booster dose is not currently required in Kenya. FUNDING: Gavi, the Vaccine Alliance, Wellcome Trust, European Society for Paediatric Infectious Diseases, and National Institute for Health Research.

Alera MT, Srikiatkhachorn A, Velasco JM, Tac-An IA, Lago CB, Clapham HE, Fernandez S, Levy JW, Thaisomboonsuk B, Klungthong C et al. 2016. Incidence of Dengue Virus Infection in Adults and Children in a Prospective Longitudinal Cohort in the Philippines. PLoS Negl Trop Dis, 10 (2), pp. e0004337. | Citations: 8 (Scopus) | Show Abstract | Read more

BACKGROUND: The mean age of dengue has been increasing in some but not all countries. We sought to determine the incidence of dengue virus (DENV) infection in adults and children in a prospective cohort study in the Philippines where dengue is hyperendemic. METHODOLOGY/PRINCIPAL FINDINGS: A prospective cohort of subjects ≥6 months old in Cebu City, Philippines, underwent active community-based surveillance for acute febrile illnesses by weekly contact. Fever history within the prior seven days was evaluated with an acute illness visit followed by 2, 5, and 8-day, and 3-week convalescent visits. Blood was collected at the acute and 3-week visits. Scheduled visits took place at enrolment and 12 months that included blood collections. Acute samples were tested by DENV PCR and acute/convalescent samples by DENV IgM/IgG ELISA to identify symptomatic infections. Enrolment and 12-month samples were tested by DENV hemagglutination inhibition (HAI) assay to identify subclinical infections. Of 1,008 enrolled subjects, 854 completed all study activities at 12 months per-protocol undergoing 868 person-years of surveillance. The incidence of symptomatic and subclinical infections was 1.62 and 7.03 per 100 person-years, respectively. However, in subjects >15 years old, only one symptomatic infection occurred whereas 27 subclinical infections were identified. DENV HAI seroprevalence increased sharply with age with baseline multitypic HAIs associated with fewer symptomatic infections. Using a catalytic model, the historical infection rate among dengue naïve individuals was estimated to be high at 11-22%/year. CONCLUSIONS/SIGNIFICANCE: In this hyperendemic area with high seroprevalence of multitypic DENV HAIs in adults, symptomatic dengue rarely occurred in individuals older than 15 years. Our findings demonstrate that dengue is primarily a pediatric disease in areas with high force of infection. However, the average age of dengue could increase if force of infection decreases over time, as is occurring in some hyperendemic countries such as Thailand.

Drake TL, Devine A, Yeung S, Day NPJ, White LJ, Lubell Y. 2016. Dynamic Transmission Economic Evaluation of Infectious Disease Interventions in Low- and Middle-Income Countries: A Systematic Literature Review. Health Econ, 25 Suppl 1 pp. 124-139. | Citations: 5 (Scopus) | Show Abstract | Read more

Economic evaluation using dynamic transmission models is important for capturing the indirect effects of infectious disease interventions. We examine the use of these methods in low- and middle-income countries, where infectious diseases constitute a major burden. This review is comprised of two parts: (1) a summary of dynamic transmission economic evaluations across all disease areas published between 2011 and mid-2014 and (2) an in-depth review of mosquito-borne disease studies focusing on health economic methods and reporting. Studies were identified through a systematic search of the MEDLINE database and supplemented by reference list screening. Fifty-seven studies were eligible for inclusion in the all-disease review. The most common subject disease was HIV/AIDS, followed by malaria. A diverse range of modelling methods, outcome metrics and sensitivity analyses were used, indicating little standardisation. Seventeen studies were included in the mosquito-borne disease review. With notable exceptions, most studies did not employ economic evaluation methods beyond calculating a cost-effectiveness ratio or net benefit. Many did not adhere to health care economic evaluations reporting guidelines, particularly with respect to full model reporting and uncertainty analysis. We present a summary of the state-of-the-art and offer recommendations for improved implementation and reporting of health economic methods in this crossover discipline.

Stuetz W, Carrara VI, Mc Gready R, Lee SJ, Sriprawat K, Po B, Hanboonkunupakarn B, Grune T, Biesalski HK, Nosten FH. 2016. Impact of Food Rations and Supplements on Micronutrient Status by Trimester of Pregnancy: Cross-Sectional Studies in the Maela Refugee Camp in Thailand. Nutrients, 8 (2), pp. 66. | Citations: 2 (Web of Science Lite) | Show Abstract | Read more

Micronutrient fortified flour (MFF), supplementary food rations and micronutrient (MN) supplements may prevent deficiencies among pregnant women. Objectives of cross-sectional surveys in 2004 (n = 533) and 2006 (n = 515) were to assess the impact of new food rations (flour, oil) and supplements on MN status by trimester of pregnancy in the Maela refugee camp. Hemoglobin, iron status, zinc, retinol, β-carotene and tryptophan decreased, while α-/γ-tocopherol and 5-methyltetrahydrofolate (5-MTHF) increased from first to third trimester. In 2006, mean zinc and α-tocopherol for each trimester was significantly higher than in 2004. The weeks of supplemented thiamine and folic acid were positively correlated with thiamine diphosphate (TDP) and 5-MTHF, but not for ferrous sulfate as iron deficiency was observed in 38.5% of third-trimester women. Frequent consumption of fish paste and owning a garden or animal were associated with significantly higher iron status, retinol, β-carotene, and 5-MTHF. In conclusion, MFF and supplementary oil were most likely to explain improved zinc and α-tocopherol status, while thiamine and folate supplements ensured high TDP and 5-MTHF in late pregnancy. MN supplements, MN-rich staple food, small gardens, and programs to improve iron compliance are promising strategies to prevent MN deficiencies during pregnancy in vulnerable populations.

Seale AC, Davies MR, Anampiu K, Morpeth SC, Nyongesa S, Mwarumba S, Smeesters PR, Efstratiou A, Karugutu R, Mturi N et al. 2016. Invasive Group A Streptococcus Infection among Children, Rural Kenya. Emerg Infect Dis, 22 (2), pp. 224-232. | Citations: 5 (Scopus) | Show Abstract | Read more

To determine the extent of group A Streptococcus (GAS) infections in sub-Saharan Africa and the serotypes that cause disease, we analyzed surveillance data for 64,741 hospital admissions in Kilifi, Kenya, during 1998-2011. We evaluated incidence, clinical presentations, and emm types that cause invasive GAS infection. We detected 370 cases; of the 369 for which we had data, most were skin and soft tissue infections (70%), severe pneumonia (23%), and primary bacteremia (14%). Overall case-fatality risk was 12%. Incidence of invasive GAS infection was 0.6 cases/1,000 live births among neonates, 101/100,000 person-years among children <1 year of age, and 35/100,000 among children <5 years of age. Genome sequencing identified 88 emm types. GAS causes serious disease in children in rural Kenya, especially neonates, and the causative organisms have considerable genotypic diversity. Benefit from the most advanced GAS type-specific vaccines may be limited, and efforts must be directed to protect against disease in regions of high incidence.

Carter MJ, Emary KR, Moore CE, Parry CM, Sona S, Putchhat H, Reaksmey S, Chanpheaktra N, Stoesser N, Dobson ADM et al. 2016. Correction: Rapid Diagnostic Tests for Dengue Virus Infection in Febrile Cambodian Children: Diagnostic Accuracy and Incorporation into Diagnostic Algorithms. PLoS Negl Trop Dis, 10 (2), pp. e0004453. | Read more

Sadique Z, Lopman B, Cooper BS, Edmunds WJ. 2016. Cost-effectiveness of Ward Closure to Control Outbreaks of Norovirus Infection in United Kingdom National Health Service Hospitals. J Infect Dis, 213 Suppl 1 (suppl 1), pp. S19-S26. | Citations: 6 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Norovirus is the most common cause of outbreaks of acute gastroenteritis in National Health Service hospitals in the United Kingdom. Wards (units) are often closed to new admissions to stop the spread of the virus, but there is limited evidence describing the cost-effectiveness of ward closure. METHODS: An economic analysis based on the results from a large, prospective, active-surveillance study of gastroenteritis outbreaks in hospitals and from an epidemic simulation study compared alternative ward closure options evaluated at different time points since first infection, assuming different efficacies of ward closure. RESULTS: A total of 232 gastroenteritis outbreaks occurring in 14 hospitals over a 1-year period were analyzed. The risk of a new outbreak in a hospital is significantly associated with the number of admission, general medical, and long-stay wards that are concurrently affected but is less affected by the level of community transmission. Ward closure leads to higher costs but reduces the number of new outbreaks by 6%-56% and the number of clinical cases by 1%-55%, depending on the efficacy of the intervention. The incremental cost per outbreak averted varies from £10 000 ($14 000) to £306 000 ($428 000), and the cost per case averted varies from £500 ($700) to £61 000 ($85 000). The cost-effectiveness of ward closure decreases as the efficacy of the intervention increases, and the cost-effectiveness increases with the timing of the intervention. The efficacy of ward closure is critical from a cost-effectiveness perspective. CONCLUSIONS: Ward closure may be cost-effective, particularly if targeted to high-throughput units.

Makendi C, Page AJ, Wren BW, Le Thi Phuong T, Clare S, Hale C, Goulding D, Klemm EJ, Pickard D, Okoro C et al. 2016. A Phylogenetic and Phenotypic Analysis of Salmonella enterica Serovar Weltevreden, an Emerging Agent of Diarrheal Disease in Tropical Regions. PLoS Negl Trop Dis, 10 (2), pp. e0004446. | Citations: 4 (Scopus) | Show Abstract | Read more

Salmonella enterica serovar Weltevreden (S. Weltevreden) is an emerging cause of diarrheal and invasive disease in humans residing in tropical regions. Despite the regional and international emergence of this Salmonella serovar, relatively little is known about its genetic diversity, genomics or virulence potential in model systems. Here we used whole genome sequencing and bioinformatics analyses to define the phylogenetic structure of a diverse global selection of S. Weltevreden. Phylogenetic analysis of more than 100 isolates demonstrated that the population of S. Weltevreden can be segregated into two main phylogenetic clusters, one associated predominantly with continental Southeast Asia and the other more internationally dispersed. Subcluster analysis suggested the local evolution of S. Weltevreden within specific geographical regions. Four of the isolates were sequenced using long read sequencing to produce high quality reference genomes. Phenotypic analysis in Hep-2 cells and in a murine infection model indicated that S. Weltevreden were significantly attenuated in these models compared to the classical S. Typhimurium reference strain SL1344. Our work outlines novel insights into this important emerging pathogen and provides a baseline understanding for future research studies.

Joubert DA, Walker T, Carrington LB, De Bruyne JT, Kien DHT, Hoang NLT, Chau NVV, Iturbe-Ormaetxe I, Simmons CP, O'Neill SL. 2016. Establishment of a Wolbachia Superinfection in Aedes aegypti Mosquitoes as a Potential Approach for Future Resistance Management. PLoS Pathog, 12 (2), pp. e1005434. | Citations: 27 (Web of Science Lite) | Show Abstract | Read more

Wolbachia pipientis is an endosymbiotic bacterium estimated to chronically infect between 40-75% of all arthropod species. Aedes aegypti, the principle mosquito vector of dengue virus (DENV), is not a natural host of Wolbachia. The transinfection of Wolbachia strains such as wAlbB, wMel and wMelPop-CLA into Ae. aegypti has been shown to significantly reduce the vector competence of this mosquito for a range of human pathogens in the laboratory. This has led to wMel-transinfected Ae. aegypti currently being released in five countries to evaluate its effectiveness to control dengue disease in human populations. Here we describe the generation of a superinfected Ae. aegypti mosquito line simultaneously infected with two avirulent Wolbachia strains, wMel and wAlbB. The line carries a high overall Wolbachia density and tissue localisation of the individual strains is very similar to each respective single infected parental line. The superinfected line induces unidirectional cytoplasmic incompatibility (CI) when crossed to each single infected parental line, suggesting that the superinfection would have the capacity to replace either of the single constituent infections already present in a mosquito population. No significant differences in fitness parameters were observed between the superinfected line and the parental lines under the experimental conditions tested. Finally, the superinfected line blocks DENV replication more efficiently than the single wMel strain when challenged with blood meals from viremic dengue patients. These results suggest that the deployment of superinfections could be used to replace single infections and may represent an effective strategy to help manage potential resistance by DENV to field deployments of single infected strains.

Takahashi S, Liao Q, Van Boeckel TP, Xing W, Sun J, Hsiao VY, Metcalf CJE, Chang Z, Liu F, Zhang J et al. 2016. Hand, Foot, and Mouth Disease in China: Modeling Epidemic Dynamics of Enterovirus Serotypes and Implications for Vaccination. PLoS Med, 13 (2), pp. e1001958. | Citations: 16 (Scopus) | Show Abstract | Read more

BACKGROUND: Hand, foot, and mouth disease (HFMD) is a common childhood illness caused by serotypes of the Enterovirus A species in the genus Enterovirus of the Picornaviridae family. The disease has had a substantial burden throughout East and Southeast Asia over the past 15 y. China reported 9 million cases of HFMD between 2008 and 2013, with the two serotypes Enterovirus A71 (EV-A71) and Coxsackievirus A16 (CV-A16) being responsible for the majority of these cases. Three recent phase 3 clinical trials showed that inactivated monovalent EV-A71 vaccines manufactured in China were highly efficacious against HFMD associated with EV-A71, but offered no protection against HFMD caused by CV-A16. To better inform vaccination policy, we used mathematical models to evaluate the effect of prospective vaccination against EV-A71-associated HFMD and the potential risk of serotype replacement by CV-A16. We also extended the model to address the co-circulation, and implications for vaccination, of additional non-EV-A71, non-CV-A16 serotypes of enterovirus. METHODS AND FINDINGS: Weekly reports of HFMD incidence from 31 provinces in Mainland China from 1 January 2009 to 31 December 2013 were used to fit multi-serotype time series susceptible-infected-recovered (TSIR) epidemic models. We obtained good model fit for the two-serotype TSIR with cross-protection, capturing the seasonality and geographic heterogeneity of province-level transmission, with strong correlation between the observed and simulated epidemic series. The national estimate of the basic reproduction number, R0, weighted by provincial population size, was 26.63 for EV-A71 (interquartile range [IQR]: 23.14, 30.40) and 27.13 for CV-A16 (IQR: 23.15, 31.34), with considerable variation between provinces (however, predictions about the overall impact of vaccination were robust to this variation). EV-A71 incidence was projected to decrease monotonically with higher coverage rates of EV-A71 vaccination. Across provinces, CV-A16 incidence in the post-EV-A71-vaccination period remained either comparable to or only slightly increased from levels prior to vaccination. The duration and strength of cross-protection following infection with EV-A71 or CV-A16 was estimated to be 9.95 wk (95% confidence interval [CI]: 3.31, 23.40) in 68% of the population (95% CI: 37%, 96%). Our predictions are limited by the necessarily short and under-sampled time series and the possible circulation of unidentified serotypes, but, nonetheless, sensitivity analyses indicate that our results are robust in predicting that the vaccine should drastically reduce incidence of EV-A71 without a substantial competitive release of CV-A16. CONCLUSIONS: The ability of our models to capture the observed epidemic cycles suggests that herd immunity is driving the epidemic dynamics caused by the multiple serotypes of enterovirus. Our results predict that the EV-A71 and CV-A16 serotypes provide a temporary immunizing effect against each other. Achieving high coverage rates of EV-A71 vaccination would be necessary to eliminate the ongoing transmission of EV-A71, but serotype replacement by CV-A16 following EV-A71 vaccination is likely to be transient and minor compared to the corresponding reduction in the burden of EV-A71-associated HFMD. Therefore, a mass EV-A71 vaccination program of infants and young children should provide significant benefits in terms of a reduction in overall HFMD burden.

Satyagraha AW, Sadhewa A, Elvira R, Elyazar I, Feriandika D, Antonjaya U, Oyong D, Subekti D, Rozi IE, Domingo GJ et al. 2016. Assessment of Point-of-Care Diagnostics for G6PD Deficiency in Malaria Endemic Rural Eastern Indonesia. PLoS Negl Trop Dis, 10 (2), pp. e0004457. | Citations: 9 (Scopus) | Show Abstract | Read more

BACKGROUND: Patients infected by Plasmodium vivax or Plasmodium ovale suffer repeated clinical attacks without primaquine therapy against latent stages in liver. Primaquine causes seriously threatening acute hemolytic anemia in patients having inherited glucose-6-phosphate dehydrogenase (G6PD) deficiency. Access to safe primaquine therapy hinges upon the ability to confirm G6PD normal status. CareStart G6PD, a qualitative G6PD rapid diagnostic test (G6PD RDT) intended for use at point-of-care in impoverished rural settings where most malaria patients live, was evaluated. METHODOLOGY/PRINCIPAL FINDINGS: This device and the standard qualitative fluorescent spot test (FST) were each compared against the quantitative spectrophotometric assay for G6PD activity as the diagnostic gold standard. The assessment occurred at meso-endemic Panenggo Ede in western Sumba Island in eastern Indonesia, where 610 residents provided venous blood. The G6PD RDT and FST qualitative assessments were performed in the field, whereas the quantitative assay was performed in a research laboratory at Jakarta. The median G6PD activity ≥ 5 U/gHb was 9.7 U/gHb and was considered 100% of normal activity. The prevalence of G6PD deficiency by quantitative assessment (<5 U/gHb) was 7.2%. Applying 30% of normal G6PD activity as the cut-off for qualitative testing, the sensitivity, specificity, positive predictive value, and negative predictive value for G6PD RDT versus FST among males were as follows: 100%, 98.7%, 89%, and 100% versus 91.7%, 92%, 55%, and 99%; P = 0.49, 0.001, 0.004, and 0.24, respectively. These values among females were: 83%, 92.7%, 17%, and 99.7% versus 100%, 92%, 18%, and 100%; P = 1.0, 0.89, 1.0 and 1.0, respectively. CONCLUSIONS/SIGNIFICANCE: The overall performance of G6PD RDT, especially 100% negative predictive value, demonstrates suitable safety for G6PD screening prior to administering hemolytic drugs like primaquine and many others. Relatively poor diagnostic performance among females due to mosaic G6PD phenotype is an inherent limitation of any current practical screening methodology.

Hamers RL. 2016. Enhancement of clinical decision making in HIV care in Africa. Lancet HIV, 3 (2), pp. e59-e60. | Read more

Tosas Auguet O, Betley JR, Stabler RA, Patel A, Ioannou A, Marbach H, Hearn P, Aryee A, Goldenberg SD, Otter JA et al. 2016. Evidence for Community Transmission of Community-Associated but Not Health-Care-Associated Methicillin-Resistant Staphylococcus Aureus Strains Linked to Social and Material Deprivation: Spatial Analysis of Cross-sectional Data. PLoS Med, 13 (1), pp. e1001944. | Citations: 5 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Identifying and tackling the social determinants of infectious diseases has become a public health priority following the recognition that individuals with lower socioeconomic status are disproportionately affected by infectious diseases. In many parts of the world, epidemiologically and genotypically defined community-associated (CA) methicillin-resistant Staphylococcus aureus (MRSA) strains have emerged to become frequent causes of hospital infection. The aim of this study was to use spatial models with adjustment for area-level hospital attendance to determine the transmission niche of genotypically defined CA- and health-care-associated (HA)-MRSA strains across a diverse region of South East London and to explore a potential link between MRSA carriage and markers of social and material deprivation. METHODS AND FINDINGS: This study involved spatial analysis of cross-sectional data linked with all MRSA isolates identified by three National Health Service (NHS) microbiology laboratories between 1 November 2011 and 29 February 2012. The cohort of hospital-based NHS microbiology diagnostic services serves 867,254 usual residents in the Lambeth, Southwark, and Lewisham boroughs in South East London, United Kingdom (UK). Isolates were classified as HA- or CA-MRSA based on whole genome sequencing. All MRSA cases identified over 4 mo within the three-borough catchment area (n = 471) were mapped to small geographies and linked to area-level aggregated socioeconomic and demographic data. Disease mapping and ecological regression models were used to infer the most likely transmission niches for each MRSA genetic classification and to describe the spatial epidemiology of MRSA in relation to social determinants. Specifically, we aimed to identify demographic and socioeconomic population traits that explain cross-area extra variation in HA- and CA-MRSA relative risks following adjustment for hospital attendance data. We explored the potential for associations with the English Indices of Deprivation 2010 (including the Index of Multiple Deprivation and several deprivation domains and subdomains) and the 2011 England and Wales census demographic and socioeconomic indicators (including numbers of households by deprivation dimension) and indicators of population health. Both CA-and HA-MRSA were associated with household deprivation (CA-MRSA relative risk [RR]: 1.72 [1.03-2.94]; HA-MRSA RR: 1.57 [1.06-2.33]), which was correlated with hospital attendance (Pearson correlation coefficient [PCC] = 0.76). HA-MRSA was also associated with poor health (RR: 1.10 [1.01-1.19]) and residence in communal care homes (RR: 1.24 [1.12-1.37]), whereas CA-MRSA was linked with household overcrowding (RR: 1.58 [1.04-2.41]) and wider barriers, which represent a combined score for household overcrowding, low income, and homelessness (RR: 1.76 [1.16-2.70]). CA-MRSA was also associated with recent immigration to the UK (RR: 1.77 [1.19-2.66]). For the area-level variation in RR for CA-MRSA, 28.67% was attributable to the spatial arrangement of target geographies, compared with only 0.09% for HA-MRSA. An advantage to our study is that it provided a representative sample of usual residents receiving care in the catchment areas. A limitation is that relationships apparent in aggregated data analyses cannot be assumed to operate at the individual level. CONCLUSIONS: There was no evidence of community transmission of HA-MRSA strains, implying that HA-MRSA cases identified in the community originate from the hospital reservoir and are maintained by frequent attendance at health care facilities. In contrast, there was a high risk of CA-MRSA in deprived areas linked with overcrowding, homelessness, low income, and recent immigration to the UK, which was not explainable by health care exposure. Furthermore, areas adjacent to these deprived areas were themselves at greater risk of CA-MRSA, indicating community transmission of CA-MRSA. This ongoing community transmission could lead to CA-MRSA becoming the dominant strain types carried by patients admitted to hospital, particularly if successful hospital-based MRSA infection control programmes are maintained. These results suggest that community infection control programmes targeting transmission of CA-MRSA will be required to control MRSA in both the community and hospital. These epidemiological changes will also have implications for effectiveness of risk-factor-based hospital admission MRSA screening programmes.

Chairat K, Jittamala P, Hanpithakpong W, Day NPJ, White NJ, Pukrittayakamee S, Tarning J. 2016. Population pharmacokinetics of oseltamivir and oseltamivir carboxylate in obese and non-obese volunteers. Br J Clin Pharmacol, 81 (6), pp. 1103-1112. | Citations: 3 (Scopus) | Show Abstract | Read more

AIMS: The aims of the present study were to compare the pharmacokinetics of oseltamivir and its active antiviral metabolite oseltamivir carboxylate in obese and non-obese individuals and to determine the effect of obesity on the pharmacokinetic properties of oseltamivir and oseltamivir carboxylate. METHODS: The population pharmacokinetic properties of oseltamivir and oseltamivir carboxylate were evaluated in 12 obese [body mass index (BMI) ≥30 kg m(-2) ) and 12 non-obese (BMI <30 kg m(-2) ) Thai adult volunteers receiving a standard dose of 75 mg and a double dose of 150 mg in a randomized sequence. Concentration-time data were collected and analysed using nonlinear mixed-effects modelling. RESULTS: The pharmacokinetics of oseltamivir and oseltamivir carboxylate were described simultaneously by first-order absorption, with a one-compartment disposition model for oseltamivir, followed by a metabolism compartment and a one-compartment disposition model for oseltamivir carboxylate. Creatinine clearance was a significant predictor of oseltamivir carboxylate clearance {3.84% increase for each 10 ml min(-1) increase in creatinine clearance [95% confidence interval (CI) 0.178%, 8.02%]}. Obese individuals had an approximately 25% (95% CI 24%, 28%) higher oseltamivir clearance, 20% higher oseltamivir volume of distribution (95% CI 19%, 23%) and 10% higher oseltamivir carboxylate clearance (95% CI 9%, 11%) compared with non-obese individuals. However, these altered pharmacokinetic properties were small and did not change the overall exposure to oseltamivir carboxylate. CONCLUSIONS: The results confirmed that a dose adjustment for oseltamivir in obese individuals is not necessary on the basis of its pharmacokinetics.

Arjyal A, Basnyat B, Nhan HT, Koirala S, Giri A, Joshi N, Shakya M, Pathak KR, Mahat SP, Prajapati SP et al. 2016. Gatifloxacin versus ceftriaxone for uncomplicated enteric fever in Nepal: an open-label, two-centre, randomised controlled trial. Lancet Infect Dis, 16 (5), pp. 535-545. | Citations: 11 (Scopus) | Show Abstract | Read more

BACKGROUND: Because treatment with third-generation cephalosporins is associated with slow clinical improvement and high relapse burden for enteric fever, whereas the fluoroquinolone gatifloxacin is associated with rapid fever clearance and low relapse burden, we postulated that gatifloxacin would be superior to the cephalosporin ceftriaxone in treating enteric fever. METHODS: We did an open-label, randomised, controlled, superiority trial at two hospitals in the Kathmandu valley, Nepal. Eligible participants were children (aged 2-13 years) and adult (aged 14-45 years) with criteria for suspected enteric fever (body temperature ≥38·0°C for ≥4 days without a focus of infection). We randomly assigned eligible patients (1:1) without stratification to 7 days of either oral gatifloxacin (10 mg/kg per day) or intravenous ceftriaxone (60 mg/kg up to 2 g per day for patients aged 2-13 years, or 2 g per day for patients aged ≥14 years). The randomisation list was computer-generated using blocks of four and six. The primary outcome was a composite of treatment failure, defined as the occurrence of at least one of the following: fever clearance time of more than 7 days after treatment initiation; the need for rescue treatment on day 8; microbiological failure (ie, blood cultures positive for Salmonella enterica serotype Typhi, or Paratyphi A, B, or C) on day 8; or relapse or disease-related complications within 28 days of treatment initiation. We did the analyses in the modified intention-to-treat population, and subpopulations with either confirmed blood-culture positivity, or blood-culture negativity. The trial was powered to detect an increase of 20% in the risk of failure. This trial was registered at, number NCT01421693, and is now closed. FINDINGS: Between Sept 18, 2011, and July 14, 2014, we screened 725 patients for eligibility. On July 14, 2014, the trial was stopped early by the data safety and monitoring board because S Typhi strains with high-level resistance to ciprofloxacin and gatifloxacin had emerged. At this point, 239 were in the modified intention-to-treat population (120 assigned to gatifloxacin, 119 to ceftriaxone). 18 (15%) patients who received gatifloxacin had treatment failure, compared with 19 (16%) who received ceftriaxone (hazard ratio [HR] 1·04 [95% CI 0·55-1·98]; p=0·91). In the culture-confirmed population, 16 (26%) of 62 patients who received gatifloxacin failed treatment, compared with four (7%) of 54 who received ceftriaxone (HR 0·24 [95% CI 0·08-0·73]; p=0·01). Treatment failure was associated with the emergence of S Typhi exhibiting resistance against fluoroquinolones, requiring the trial to be stopped. By contrast, in patients with a negative blood culture, only two (3%) of 58 who received gatifloxacin failed treatment versus 15 (23%) of 65 who received ceftriaxone (HR 7·50 [95% CI 1·71-32·80]; p=0·01). A similar number of non-serious adverse events occurred in each treatment group, and no serious events were reported. INTERPRETATION: Our results suggest that fluoroquinolones should no longer be used for treatment of enteric fever in Nepal. Additionally, under our study conditions, ceftriaxone was suboptimum in a high proportion of patients with culture-negative enteric fever. Since antimicrobials, specifically fluoroquinolones, are one of the only routinely used control measures for enteric fever, the assessment of novel diagnostics, new treatment options, and use of existing vaccines and development of next-generation vaccines are now a high priority. FUNDING: Wellcome Trust and Li Ka Shing Foundation.

Murungi LM, Sondén K, Llewellyn D, Rono J, Guleid F, Williams AR, Ogada E, Thairu A, Färnert A, Marsh K et al. 2016. Targets and Mechanisms Associated with Protection from Severe Plasmodium falciparum Malaria in Kenyan Children. Infect Immun, 84 (4), pp. 950-963. | Citations: 12 (Web of Science Lite) | Show Abstract | Read more

Severe malaria (SM) is a life-threatening complication of infection with Plasmodium falciparum Epidemiological observations have long indicated that immunity against SM is acquired relatively rapidly, but prospective studies to investigate its immunological basis are logistically challenging and have rarely been undertaken. We investigated the merozoite targets and antibody-mediated mechanisms associated with protection against SM in Kenyan children aged 0 to 2 years. We designed a unique prospective matched case-control study of well-characterized SM clinical phenotypes nested within a longitudinal birth cohort of children (n= 5,949) monitored over the first 2 years of life. We quantified immunological parameters in sera collected before the SM event in cases and their individually matched controls to evaluate the prospective odds of developing SM in the first 2 years of life. Anti-AMA1 antibodies were associated with a significant reduction in the odds of developing SM (odds ratio [OR] = 0.37; 95% confidence interval [CI] = 0.15 to 0.90; P= 0.029) after adjustment for responses to all other merozoite antigens tested, while those against MSP-2, MSP-3, Plasmodium falciparum Rh2 [PfRh2], MSP-119, and the infected red blood cell surface antigens were not. The combined ability of total IgG to inhibit parasite growth and mediate the release of reactive oxygen species from neutrophils was associated with a marked reduction in the odds of developing SM (OR = 0.07; 95% CI = 0.006 to 0.82;P= 0.03). Assays of these two functional mechanisms were poorly correlated (Spearman rank correlation coefficient [rs] = 0.12;P= 0.07). Our data provide epidemiological evidence that multiple antibody-dependent mechanisms contribute to protective immunity via distinct targets whose identification could accelerate the development of vaccines to protect against SM.

Heemskerk AD, Bang ND, Mai NTH, Chau TTH, Phu NH, Loc PP, Chau NVV, Hien TT, Dung NH, Lan NTN et al. 2016. Intensified Antituberculosis Therapy in Adults with Tuberculous Meningitis. N Engl J Med, 374 (2), pp. 124-134. | Citations: 38 (Scopus) | Show Abstract | Read more

BACKGROUND: Tuberculous meningitis is often lethal. Early antituberculosis treatment and adjunctive treatment with glucocorticoids improve survival, but nearly one third of patients with the condition still die. We hypothesized that intensified antituberculosis treatment would enhance the killing of intracerebral Mycobacterium tuberculosis organisms and decrease the rate of death among patients. METHODS: We performed a randomized, double-blind, placebo-controlled trial involving human immunodeficiency virus (HIV)-infected adults and HIV-uninfected adults with a clinical diagnosis of tuberculous meningitis who were admitted to one of two Vietnamese hospitals. We compared a standard, 9-month antituberculosis regimen (which included 10 mg of rifampin per kilogram of body weight per day) with an intensified regimen that included higher-dose rifampin (15 mg per kilogram per day) and levofloxacin (20 mg per kilogram per day) for the first 8 weeks of treatment. The primary outcome was death by 9 months after randomization. RESULTS: A total of 817 patients (349 of whom were HIV-infected) were enrolled; 409 were randomly assigned to receive the standard regimen, and 408 were assigned to receive intensified treatment. During the 9 months of follow-up, 113 patients in the intensified-treatment group and 114 patients in the standard-treatment group died (hazard ratio, 0.94; 95% confidence interval, 0.73 to 1.22; P=0.66). There was no evidence of a significant differential effect of intensified treatment in the overall population or in any of the subgroups, with the possible exception of patients infected with isoniazid-resistant M. tuberculosis. There were also no significant differences in secondary outcomes between the treatment groups. The overall number of adverse events leading to treatment interruption did not differ significantly between the treatment groups (64 events in the standard-treatment group and 95 events in the intensified-treatment group, P=0.08). CONCLUSIONS: Intensified antituberculosis treatment was not associated with a higher rate of survival among patients with tuberculous meningitis than standard treatment. (Funded by the Wellcome Trust and the Li Ka Shing Foundation; Current Controlled Trials number, ISRCTN61649292.).

Whitehead J, Olliaro P, Lang T, Horby P. 2016. Trial design for evaluating novel treatments during an outbreak of an infectious disease. Clin Trials, 13 (1), pp. 31-38. | Citations: 8 (Web of Science Lite) | Show Abstract | Read more

Tragically, the outbreak of Ebola that started in West Africa in 2014 has been far more extensive and damaging than any previous outbreaks. The duration of the outbreak has, for the first time, allowed the clinical evaluation of Ebola treatments. This article discusses the designs used for two such clinical trials which have recruited patients in Liberia and Sierra Leone. General principles are outlined for trial designs intended to be deployed quickly, adapt flexibly and provide results soon enough to influence the course of the current epidemic rather than just providing evidence for use should Ebola break out again. Lessons are drawn for the conduct of clinical research in future outbreaks of infectious diseases, where the sequence of events may or may not be similar to the West African Ebola epidemic.

Heemskerk AD, Bang ND, Mai NTH, Chau TTH, Phu NH, Loc PP, Chau NVV, Hien TT, Dung NH, Lan NTN et al. 2016. Intensified Antituberculosis Therapy in Adults with Tuberculous Meningitis NEW ENGLAND JOURNAL OF MEDICINE, 374 (2), pp. 124-134. | Citations: 34 (Web of Science Lite) | Read more

Hamers RL, van Gool T, Goorhuis A. 2016. Benznidazole for Chronic Chagas' Cardiomyopathy. N Engl J Med, 374 (2), pp. 188. | Read more

Ribolzi O, Rochelle-Newall E, Dittrich S, Auda Y, Newton PN, Rattanavong S, Knappik M, Soulileuth B, Sengtaheuanghoung O, Dance DAB, Pierret A. 2016. Land use and soil type determine the presence of the pathogen Burkholderia pseudomallei in tropical rivers. Environ Sci Pollut Res Int, 23 (8), pp. 7828-7839. | Citations: 8 (Web of Science Lite) | Show Abstract | Read more

Burkholderia pseudomallei is the bacterium that causes melioidosis in humans. While B. pseudomallei is known to be endemic in South East Asia (SEA), the occurrence of the disease in other parts of the tropics points towards a potentially large global distribution. We investigated the environmental factors that influence the presence (and absence) of B. pseudomallei in a tropical watershed in SEA. Our main objective was to determine whether there is a link between the presence of the organism in the hydrographic network and the upstream soil and land-use type. The presence of B. pseudomallei was determined using a specific quantitative real-time PCR assay following enrichment culture. Land use, soil, geomorphology, and environmental data were then analyzed using partial least squares discriminant analysis (PLSDA) to compare the B. pseudomallei positive and negative sites. Soil type in the surrounding catchment and turbidity had a strong positive influence on the presence (acrisols and luvisols) or absence (ferralsols) of B. pseudomallei. Given the strong apparent links between soil characteristics, water turbidity, and the presence/absence of B. pseudomallei, actions to raise public awareness about factors increasing the risk of exposure should be undertaken in order to reduce the incidence of melioidosis in regions of endemicity.

Vu BNT, Jafari AJ, Aardema M, Tran HKT, Nguyen DNT, Dao TT, Nguyen TV, Tran TK, Nguyen CKT, Fox A et al. 2016. Population structure of colonizing and invasive Staphylococcus aureus strains in northern Vietnam. J Med Microbiol, 65 (4), pp. 298-305. | Citations: 3 (Scopus) | Show Abstract | Read more

Staphylococcus aureus is an important global health problem worldwide. There is still scarce information on the population structure of S. aureus strains in Asia, where the majority of the world population lives. This study characterizes the diversity of S. aureus strains in northern Vietnam through multilocus sequence typing (MLST). 85 carriage isolates from community and 77 invasive isolates from the clinical setting were selected and tested for methicillin resistance and the presence of Panton-Valentine Leukocidin (PVL). MLST was performed on these isolates, of which CC59 (25.4%), CC188 (17.3%), and CC45 (16.7%) were the predominant clonal complexes (CC). CC59-carriage isolates were significantly lower in rates of MRSA than their corresponding clinical group isolates (32% vs. 83%). There were no significant differences in rates of MRSA between carriage isolates and clinical isolates of CC45 and CC188. CC59-carriage isolates were significantly lower in rates of PVL+ than CC59-clinical isolates (32% vs. 83%), but the converse was shown in CC45 isolates (14% vs. 0% respectively). This study reveals vast differences in the molecular epidemiology and population structure of S. aureus in community and clinical settings in Vietnam. Nevertheless, the data underline the spread of virulent and/or resistant strains (MRSA and/or PVL+) in the community, suggesting the necessity of further surveillance to determine the reasoning of transmission of these strains (i.e. MRSA/PVL+) outside clinical settings.

Bousfield R, Thyl M, Samol O, Rithea L, Sona S, Chhat HP, Poda S, Moore CE, Chheng K, Kumar V et al. 2016. A retrospective study of factors which determine a negative blood culture in Cambodian children diagnosed with enteric fever. Paediatr Int Child Health, pp. 1-7. | Show Abstract | Read more

BACKGROUND: Blood cultures are used to confirm a diagnosis of enteric fever but reported sensitivities can be as low as 40%. AIMS: To determine the factors associated with a negative blood culture in Cambodian children with suspected enteric fever. METHODS: In a retrospective study of hospitalised Cambodian children given a discharge diagnosis of enteric fever, the following factors associated with a negative blood culture were analysed: age, blood culture volume, prior antibiotic therapy, duration of illness and disease severity. RESULTS: In 227 hospitalised Cambodian children with a discharge diagnosis of enteric fever, it was confirmed in 70% by a positive blood culture. There was no association between a negative blood culture and younger age, lower blood volumes for culture, prior antibiotic therapy, a late presentation or milder disease. CONCLUSIONS: Although blood culture sensitivity was higher than expected, alternative simple, rapid and sensitive tests are needed for diagnosing enteric fever.

Moore CE, Sona S, Poda S, Putchhat H, Kumar V, Sopheary S, Stoesser N, Bousfield R, Day N, Parry CM. 2016. Antimicrobial susceptibility of uropathogens isolated from Cambodian children. Paediatr Int Child Health, 36 (2), pp. 1-5. | Citations: 4 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Bacterial resistance to commonly used antimicrobials is an increasing problem in Asia but information concerning the antimicrobial susceptibility of bacteria causing urinary tract infections (UTIs) in children is limited. METHODS: This was a 5-year retrospective study of children with suspected UTI attending a paediatric hospital in north-west Cambodia. Urines with a positive culture containing a single organism with a count of >105 colony-forming units (CFU)/ml were considered diagnostic of infection. The organism was identified and the resistance pattern (using CLSI guidelines) and presence of an extended-spectrum β-lactamase (ESBL) phenotype was determined. RESULTS: In total, there were 217 episodes of infection, 210 (97%) with Gram-negative bacteria. Escherichia coli was the most common infecting isolate with high levels of resistance to most oral antibiotics, except nitrofurantoin. Nearly half of the E. coli (44%) were extended-spectrum cephalosporin (ESC)-resistant with the proportion increasing significantly over the 5-year period. ESC-resistant E. coli were more likely to be multi-drug-resistant and 91% demonstrated an ESBL phenotype. CONCLUSION: The data highlight the importance of microbiological surveillance of UTIs in children, particularly in areas where there are known to be multiply resistant organisms.

Rosenberger KD, Lum L, Alexander N, Junghanss T, Wills B, Jaenisch T, DENCO Clinical Study Group. 2016. Vascular leakage in dengue--clinical spectrum and influence of parenteral fluid therapy. Trop Med Int Health, 21 (3), pp. 445-453. | Citations: 3 (Web of Science Lite) | Show Abstract | Read more

OBJECTIVE: Clinical management of dengue relies on careful monitoring of fluid balance combined with judicious intravenous (IV) fluid therapy. However, in patients with significant vascular leakage, IV fluids may aggravate serosal fluid accumulation and result in respiratory distress. METHODS: Trained physicians followed suspected dengue cases prospectively at seven hospitals across Asia and Latin America, using a comprehensive case report form that included daily clinical assessment and detailed documentation of parenteral fluid therapy. Applying Cox regression, we evaluated risk factors for the development of shock or respiratory distress with fluid accumulation. RESULTS: Most confirmed dengue patients (1524/1734, 88%) never experienced dengue shock syndrome (DSS). Among those with DSS, 176/210 (84%) had fluid accumulation, and in the majority (83%), this was detectable clinically. Among all cases with clinically detectable fluid accumulation, 179/447 (40%) were diagnosed with shock or respiratory distress. The risk for respiratory distress with fluid accumulation increased significantly as the infused volume over the preceding 24 h increased (hazard ratio 1.18 per 10 ml/kg increase; P < 0.001). Longer duration of IV therapy, use of a fluid bolus in the preceding 24 h, female gender and poor nutrition also constituted independent risk factors. CONCLUSIONS: Shock and respiratory distress are relatively rare manifestations of dengue, but some evidence of fluid accumulation is seen in around 50% of cases. IV fluids play a crucial role in management, but they must be administered with caution. Clinically and/or radiologically detectable fluid accumulations have potential as intermediate severity endpoints for therapeutic intervention trials and/or pathogenesis studies.

Limmathurotsakul D, Golding N, Dance DA, Messina JP, Pigott DM, Moyes CL, Rolim DB, Bertherat E, Day NP, Peacock SJ, Hay SI. 2016. Predicted global distribution of Burkholderia pseudomallei and burden of melioidosis. Nat Microbiol, 1 (1), pp. 15008-15008. | Citations: 87 (Scopus) | Show Abstract | Read more

Burkholderia pseudomallei, a highly pathogenic bacterium that causes melioidosis, is commonly found in soil in Southeast Asia and Northern Australia1,2. Melioidosis can be difficult to diagnose due to its diverse clinical manifestations and the inadequacy of conventional bacterial identification methods3. The bacterium is intrinsically resistant to a wide range of antimicrobials, and treatment with ineffective antimicrobials may result in case fatality rates (CFRs) exceeding 70%4,5. The importation of infected animals has, in the past, spread melioidosis to non-endemic areas6,7. The global distribution of B. pseudomallei and burden of melioidosis, however, remain poorly understood. Here, we map documented human and animal cases, and the presence of environmental B. pseudomallei, and combine this in a formal modelling framework8-10 to estimate the global burden of melioidosis. We estimate there to be 165,000 (95% credible interval 68,000-412,000) human melioidosis cases per year worldwide, of which 89,000 (36,000-227,000) die. Our estimates suggest that melioidosis is severely underreported in the 45 countries in which it is known to be endemic and that melioidosis is likely endemic in a further 34 countries which have never reported the disease. The large numbers of estimated cases and fatalities emphasise that the disease warrants renewed attention from public health officials and policy makers.

Limmathurotsakul D, Golding N, Dance DAB, Messina JP, Pigott DM, Moyes CL, Rolim DB, Bertherat E, Day NPJ, Peacock SJ, Hay SI. 2016. Predicted global distribution of Burkholderia pseudomallei and burden of melioidosis. Nat Microbiol, 1 pp. 15008. | Show Abstract | Read more

Burkholderia pseudomallei, a highly pathogenic bacterium that causes melioidosis, is commonly found in soil in Southeast Asia and Northern Australia(1,2). Melioidosis can be difficult to diagnose due to its diverse clinical manifestations and the inadequacy of conventional bacterial identification methods(3). The bacterium is intrinsically resistant to a wide range of antimicrobials, and treatment with ineffective antimicrobials may result in case fatality rates (CFRs) exceeding 70%(4,5). The importation of infected animals has, in the past, spread melioidosis to non-endemic areas(6,7). The global distribution of B. pseudomallei and the burden of melioidosis, however, remain poorly understood. Here, we map documented human and animal cases and the presence of environmental B. pseudomallei and combine this in a formal modelling framework(8-10) to estimate the global burden of melioidosis. We estimate there to be 165,000 (95% credible interval 68,000-412,000) human melioidosis cases per year worldwide, from which 89,000 (36,000-227,000) people die. Our estimates suggest that melioidosis is severely underreported in the 45 countries in which it is known to be endemic and that melioidosis is probably endemic in a further 34 countries that have never reported the disease. The large numbers of estimated cases and fatalities emphasize that the disease warrants renewed attention from public health officials and policy makers.

Cuong NV, Truc VNT, Nhung NT, Thanh TT, Chieu TTB, Hieu TQ, Men NT, Mai HH, Chi HT, Boni MF et al. 2016. Highly Pathogenic Avian Influenza Virus A/H5N1 Infection in Vaccinated Meat Duck Flocks in the Mekong Delta of Vietnam. Transbound Emerg Dis, 63 (2), pp. 127-135. | Citations: 2 (Scopus) | Show Abstract | Read more

We investigated episodes of suspected highly pathogenic avian influenza (HPAI)-like illness among 12 meat duck flocks in two districts in Tien Giang province (Mekong Delta, Vietnam) in November 2013. In total, duck samples from 8 of 12 farms tested positive for HPAI virus subtype A/haemagglutinin 5 and neuraminidase 1 (H5N1) by real-time RT-PCR. Sequencing results confirmed clade of as the cause of the outbreaks. Most (7/8) laboratory-confirmed positive flocks had been vaccinated with inactivated HPAI H5N1 clade 2.3.4 vaccines <6 days prior to onset of clinical signs. A review of vaccination data in relation to estimated production in the area suggested that vaccination efforts were biased towards larger flocks and that vaccination coverage was low [21.2% ducks vaccinated with two shots (range by district 7.4-34.9%)]. The low-coverage data, the experimental evidence of lack of cross-protection conferred by the currently used vaccines based on clade 2.3.4 together with the short lifespan of meat duck flocks (60-70 days), suggest that vaccination is not likely to be effective as a tool for control of H5N1 infection in meat duck flocks in the area.

Tan J, Pieper K, Piccoli L, Abdi A, Perez MF, Geiger R, Tully CM, Jarrossay D, Maina Ndungu F, Wambua J et al. 2016. A LAIR1 insertion generates broadly reactive antibodies against malaria variant antigens. Nature, 529 (7584), pp. 105-109. | Citations: 25 (Web of Science Lite) | Show Abstract | Read more

Plasmodium falciparum antigens expressed on the surface of infected erythrocytes are important targets of naturally acquired immunity against malaria, but their high number and variability provide the pathogen with a powerful means of escape from host antibodies. Although broadly reactive antibodies against these antigens could be useful as therapeutics and in vaccine design, their identification has proven elusive. Here we report the isolation of human monoclonal antibodies that recognize erythrocytes infected by different P. falciparum isolates and opsonize these cells by binding to members of the RIFIN family. These antibodies acquired broad reactivity through a novel mechanism of insertion of a large DNA fragment between the V and DJ segments. The insert, which is both necessary and sufficient for binding to RIFINs, encodes the entire 98 amino acid collagen-binding domain of LAIR1, an immunoglobulin superfamily inhibitory receptor encoded on chromosome 19. In each of the two donors studied, the antibodies are produced by a single expanded B-cell clone and carry distinct somatic mutations in the LAIR1 domain that abolish binding to collagen and increase binding to infected erythrocytes. These findings illustrate, with a biologically relevant example, a novel mechanism of antibody diversification by interchromosomal DNA transposition and demonstrate the existence of conserved epitopes that may be suitable candidates for the development of a malaria vaccine.

van Griensven J, Edwards T, de Lamballerie X, Semple MG, Gallian P, Baize S, Horby PW, Raoul H, Magassouba N, Antierens A et al. 2016. Evaluation of Convalescent Plasma for Ebola Virus Disease in Guinea. N Engl J Med, 374 (1), pp. 33-42. | Citations: 75 (Scopus) | Show Abstract | Read more

BACKGROUND: In the wake of the recent outbreak of Ebola virus disease (EVD) in several African countries, the World Health Organization prioritized the evaluation of treatment with convalescent plasma derived from patients who have recovered from the disease. We evaluated the safety and efficacy of convalescent plasma for the treatment of EVD in Guinea. METHODS: In this nonrandomized, comparative study, 99 patients of various ages (including pregnant women) with confirmed EVD received two consecutive transfusions of 200 to 250 ml of ABO-compatible convalescent plasma, with each unit of plasma obtained from a separate convalescent donor. The transfusions were initiated on the day of diagnosis or up to 2 days later. The level of neutralizing antibodies against Ebola virus in the plasma was unknown at the time of administration. The control group was 418 patients who had been treated at the same center during the previous 5 months. The primary outcome was the risk of death during the period from 3 to 16 days after diagnosis with adjustments for age and the baseline cycle-threshold value on polymerase-chain-reaction assay; patients who had died before day 3 were excluded. The clinically important difference was defined as an absolute reduction in mortality of 20 percentage points in the convalescent-plasma group as compared with the control group. RESULTS: A total of 84 patients who were treated with plasma were included in the primary analysis. At baseline, the convalescent-plasma group had slightly higher cycle-threshold values and a shorter duration of symptoms than did the control group, along with a higher frequency of eye redness and difficulty in swallowing. From day 3 to day 16 after diagnosis, the risk of death was 31% in the convalescent-plasma group and 38% in the control group (risk difference, -7 percentage points; 95% confidence interval [CI], -18 to 4). The difference was reduced after adjustment for age and cycle-threshold value (adjusted risk difference, -3 percentage points; 95% CI, -13 to 8). No serious adverse reactions associated with the use of convalescent plasma were observed. CONCLUSIONS: The transfusion of up to 500 ml of convalescent plasma with unknown levels of neutralizing antibodies in 84 patients with confirmed EVD was not associated with a significant improvement in survival. (Funded by the European Union's Horizon 2020 Research and Innovation Program and others; number, NCT02342171.).

Mackinnon MJ, Ndila C, Uyoga S, Macharia A, Snow RW, Band G, Rautanen A, Rockett KA, Kwiatkowski DP, Williams TN. 2016. Environmental Correlation Analysis for Genes Associated with Protection against Malaria. Mol Biol Evol, 33 (5), pp. 1188-1204. | Citations: 5 (Scopus) | Show Abstract | Read more

Genome-wide searches for loci involved in human resistance to malaria are currently being conducted on a large scale in Africa using case-control studies. Here, we explore the utility of an alternative approach-"environmental correlation analysis, ECA," which tests for clines in allele frequencies across a gradient of an environmental selection pressure-to identify genes that have historically protected against death from malaria. We collected genotype data from 12,425 newborns on 57 candidate malaria resistance loci and 9,756 single nucleotide polymorphisms (SNPs) selected at random from across the genome, and examined their allele frequencies for geographic correlations with long-term malaria prevalence data based on 84,042 individuals living under different historical selection pressures from malaria in coastal Kenya. None of the 57 candidate SNPs showed significant (P < 0.05) correlations in allele frequency with local malaria transmission intensity after adjusting for population structure and multiple testing. In contrast, two of the random SNPs that had highly significant correlations (P < 0.01) were in genes previously linked to malaria resistance, namely, CDH13, encoding cadherin 13, and HS3ST3B1, encoding heparan sulfate 3-O-sulfotransferase 3B1. Both proteins play a role in glycoprotein-mediated cell-cell adhesion which has been widely implicated in cerebral malaria, the most life-threatening form of this disease. Other top genes, including CTNND2 which encodes δ-catenin, a molecular partner to cadherin, were significantly enriched in cadherin-mediated pathways affecting inflammation of the brain vascular endothelium. These results demonstrate the utility of ECA in the discovery of novel genes and pathways affecting infectious disease.

Kangoye DT, Mensah VA, Murungi LM, Nkumama I, Nebie I, Marsh K, Cisse B, Bejon P, Osier FHA, Sirima SB, MVVC Infant Immunology Study Group. 2016. Dynamics and role of antibodies to Plasmodium falciparum merozoite antigens in children living in two settings with differing malaria transmission intensity. Vaccine, 34 (1), pp. 160-166. | Citations: 5 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Young infants have reduced susceptibility to febrile malaria compared with older children, but the mechanism for this remains unclear. There are conflicting data on the role of passively acquired antibodies. Here, we examine antibody titres to merozoite surface antigens in the protection of children in their first two years of life in two settings with differing malaria transmission intensity and compare these titres to previously established protective thresholds. METHODS: Two cohorts of children aged four to six weeks were recruited in Banfora, Burkina and Keur Soce, Senegal and followed up for two years. Malaria infections were detected by light microscopic examination of blood smears collected at active and passive case detection visits. The titres of antibodies to the Plasmodium falciparum recombinant merozoite proteins (AMA1-3D7, MSP1-19, MSP2-Dd2, and MSP3-3D7) were measured by enzyme-linked immunosorbent assay at 1-6, 9, 12, 15 and 18 months of age and compared with the protective thresholds established in Kenyan children. RESULTS: Antibody titres were below the protective thresholds throughout the study period and we did not find any association with protection against febrile malaria. Antibodies to AMA1 and MSP1-19 appeared to be markers of exposure in the univariate analysis (and so associated with increasing risk) and adjusting for exposure reduced the strength and significance of this association. CONCLUSION: The antibody levels we measured are unlikely to be responsible for the apparent protection against febrile malaria seen in young infants. Further work to identify protective antibody responses might include functional assays and a wider range of antigens.

Geskus RB, González C, Torres M, Del Romero J, Viciana P, Masiá M, Blanco JR, Iribarren M, De Sanjosé S, Hernández-Novoa B et al. 2016. Incidence and clearance of anal high-risk human papillomavirus in HIV-positive men who have sex with men: estimates and risk factors. AIDS, 30 (1), pp. 37-44. | Citations: 8 (Scopus) | Show Abstract | Read more

BACKGROUND: To estimate incidence and clearance of high-risk human papillomavirus (HR-HPV), and their risk factors, in men who have sex with men (MSM) recently infected by HIV in Spain; 2007-2013. METHODS: Multicenter cohort. HR-HPV infection was determined and genotyped with linear array. Two-state Markov models and Poisson regression were used. RESULTS: We analysed 1570 HR-HPV measurements of 612 MSM over 13 608 person-months (p-m) of follow-up. Median (mean) number of measurements was 2 (2.6), median time interval between measurements was 1.1 years (interquartile range: 0.89-1.4). Incidence ranged from 9.0 [95% confidence interval (CI) 6.8-11.8] per 1000 p-m for HPV59 to 15.9 (11.7-21.8) per 1000 p-m for HPV51. HPV16 and HPV18 had slightly above average incidence: 11.9/1000 p-m and 12.8/1000 p-m. HPV16 showed the lowest clearance for both 'prevalent positive' (15.7/1000 p-m; 95% CI 12.0-20.5) and 'incident positive' infections (22.1/1000 p-m; 95% CI 11.8-41.1). More sexual partners increased HR-HPV incidence, although it was not statistically significant. Age had a strong effect on clearance (P-value < 0.001) due to the elevated rate in MSM under age 25; the effect of HIV-RNA viral load was more gradual, with clearance rate decreasing at higher HIV-RNA viral load (P-value 0.008). CONCLUSION: No large variation in incidence by HR-HPV type was seen. The most common incident types were HPV51, HPV52, HPV31, HPV18 and HPV16. No major variation in clearance by type was observed, with the exception of HPV16 which had the highest persistence and potentially, the strongest oncogenic capacity. Those aged below 25 or with low HIV-RNA- viral load had the highest clearance.

Mooij SH, van Santen DK, Geskus RB, van der Sande MAB, Coutinho RA, Stolte IG, Snijders PJF, Meijer CJLM, Speksnijder AGCL, de Vries HJC et al. 2016. The effect of HIV infection on anal and penile human papillomavirus incidence and clearance: a cohort study among MSM. AIDS, 30 (1), pp. 121-132. | Citations: 9 (Scopus) | Show Abstract | Read more

OBJECTIVES: A large portion of anogenital cancers is caused by high-risk human papillomavirus (hrHPV) infections, which are especially common in HIV-infected men. We aimed to compare the incidence and clearance of anal and penile hrHPV infection between HIV-infected and HIV-negative MSM. DESIGN: Analyses of longitudinal data from a prospective cohort study. METHODS: MSM aged 18 years or older were recruited in Amsterdam, the Netherlands, and followed-up semi-annually for 24 months. At each visit, participants completed risk-factor questionnaires. Anal and penile self-samples were tested for HPV DNA using the SPF10-PCR DEIA/LiPA25 system. Effects on incidence and clearance rates were quantified via Poisson regression, using generalized estimating equations to correct for multiple hrHPV types. RESULTS: Seven hundred and fifty MSM with a median age of 40 years (interquartile 35-48) were included in the analyses, of whom 302 (40%) were HIV-infected. The incidence rates of hrHPV were significantly higher in HIV-infected compared with HIV-negative MSM [adjusted incidence rate ratio (aIRR) 1.6; 95% confidence interval (CI) 1.3-2.1 for anal and aIRR 1.4; 95%CI 1.0-2.1 for penile infection]. The clearance rate of hrHPV was significantly lower for anal [adjusted clearance rate ratio (aCRR) 0.7; 95%CI 0.6-0.9], but not for penile infection (aCRR 1.3; 95%CI 1.0-1.7). HrHPV incidence or clearance did not differ significantly by nadir CD4 cell count. CONCLUSION: Increased anal and penile hrHPV incidence rates and decreased anal hrHPV clearance rates were found in HIV-infected compared with HIV-negative MSM, after adjusting for sexual behavior. Our findings suggest an independent effect of HIV infection on anal hrHPV infections.

Hodkinson P, Argent A, Wallis L, Reid S, Perera R, Harrison S, Thompson M, English M, Maconochie I, Ward A. 2016. Pathways to Care for Critically Ill or Injured Children: A Cohort Study from First Presentation to Healthcare Services through to Admission to Intensive Care or Death. PLoS One, 11 (1), pp. e0145473. | Citations: 8 (Web of Science Lite) | Show Abstract | Read more

PURPOSE: Critically ill or injured children require prompt identification, rapid referral and quality emergency management. We undertook a study to evaluate the care pathway of critically ill or injured children to identify preventable failures in the care provided. METHODS: A year-long cohort study of critically ill and injured children was performed in Cape Town, South Africa, from first presentation to healthcare services until paediatric intensive care unit (PICU) admission or emergency department death, using expert panel review of medical records and caregiver interview. Main outcomes were expert assessment of overall quality of care; avoidability of severity of illness and PICU admission or death and the identification of modifiable factors. RESULTS: The study enrolled 282 children, 252 emergency PICU admissions, and 30 deaths. Global quality of care was graded good in 10% of cases, with half having at least one major impact modifiable factor. Key modifiable factors related to access to care and identification of the critically ill, assessment of severity, inadequate resuscitation, and delays in decision making and referral. Children were transferred with median time from first presentation to PICU admission of 12.3 hours. There was potentially avoidable severity of illness in 185 (74%) of children, and death prior to PICU admission was avoidable in 17/30 (56.7%) of children. CONCLUSIONS: The study presents a novel methodology, examining quality of care across an entire system, and highlighting the complexity of the pathway and the modifiable events amenable to interventions, that could reduce mortality and morbidity, and optimize utilization of scarce critical care resources; as well as demonstrating the importance of continuity and quality of care.

Karkey A, Jombart T, Walker AW, Thompson CN, Torres A, Dongol S, Tran Vu Thieu N, Pham Thanh D, Tran Thi Ngoc D, Voong Vinh P et al. 2016. The Ecological Dynamics of Fecal Contamination and Salmonella Typhi and Salmonella Paratyphi A in Municipal Kathmandu Drinking Water. PLoS Negl Trop Dis, 10 (1), pp. e0004346. | Citations: 9 (Web of Science Lite) | Show Abstract | Read more

One of the UN sustainable development goals is to achieve universal access to safe and affordable drinking water by 2030. It is locations like Kathmandu, Nepal, a densely populated city in South Asia with endemic typhoid fever, where this goal is most pertinent. Aiming to understand the public health implications of water quality in Kathmandu we subjected weekly water samples from 10 sources for one year to a range of chemical and bacteriological analyses. We additionally aimed to detect the etiological agents of typhoid fever and longitudinally assess microbial diversity by 16S rRNA gene surveying. We found that the majority of water sources exhibited chemical and bacterial contamination exceeding WHO guidelines. Further analysis of the chemical and bacterial data indicated site-specific pollution, symptomatic of highly localized fecal contamination. Rainfall was found to be a key driver of this fecal contamination, correlating with nitrates and evidence of S. Typhi and S. Paratyphi A, for which DNA was detectable in 333 (77%) and 303 (70%) of 432 water samples, respectively. 16S rRNA gene surveying outlined a spectrum of fecal bacteria in the contaminated water, forming complex communities again displaying location-specific temporal signatures. Our data signify that the municipal water in Kathmandu is a predominant vehicle for the transmission of S. Typhi and S. Paratyphi A. This study represents the first extensive spatiotemporal investigation of water pollution in an endemic typhoid fever setting and implicates highly localized human waste as the major contributor to poor water quality in the Kathmandu Valley.

Canavati SE, Lawford HLS, Fatunmbi BS, Lek D, Leang R, Top Samphor N, Dondorp AM, Huy R, Kazadi WM. 2016. The Cambodia Research Consortium: expediting research for malaria elimination with the emergency response to artemisinin resistance framework. Malar J, 15 (1), pp. 5. | Citations: 2 (Scopus) | Show Abstract | Read more

This commentary offers insight into how to best address barriers that may hinder the translation of malaria research findings into policy. It also proposes viable methods of implementing these policies in Cambodia. Currently, a wide range of malaria research is being conducted by in-country stakeholders, including Cambodia's National Programme for Parasitology, Entomology and Malaria Control's (CNM), non-governmental organizations, and academic institutions. Coordinating research amongst these partners, as well as within the Ministry of Health, is a challenge. Results are rarely disseminated widely and seldom inform programme and policy decisions. CNM and its research partners have severely limited access to each other's databases. This lack of accessibility, timeliness, engagement and cooperation between CNM and its partners greatly impacts overall research efficiency in this field, and is stifling innovation both within and beyond CNM. Cambodia has set a goal to eradicate all forms of malaria by 2030. As countries approach the elimination phase, there is a greater need for sharing research-generated evidence amongst partners, in order to ensure that appropriate and impactful activities are conducted. The Cambodian Research Consortium was established to serve as a framework for partners, stakeholders and researchers to share research projects, information and results, and to promote the goals of CNM. The sharing of malaria research results will help to inform prevention, control and elimination activities in the country. It will also determine and address the country's operational research needs, and could potentially become a framework model to be used in other countries aiming to transition from malaria control to elimination.

Kvissberg MA, Dalvi PS, Kerac M, Voskuijl W, Berkley JA, Priebe MG, Bandsma RHJ. 2016. Carbohydrate malabsorption in acutely malnourished children and infants: a systematic review. Nutr Rev, 74 (1), pp. 48-58. | Citations: 4 (Web of Science Lite) | Show Abstract | Read more

CONTEXT: Severe acute malnutrition (SAM) accounts for approximately 1 million child deaths per year. High mortality is linked with comorbidities, such as diarrhea and pneumonia. OBJECTIVE: The aim of this systematic review was to determine the extent to which carbohydrate malabsorption occurs in children with SAM. DATA SOURCES: The PubMed and Embase databases were searched. Reference lists of selected articles were checked. DATA EXTRACTION: All observational and controlled intervention studies involving children with SAM in which direct or indirect measures of carbohydrate absorption were analyzed were eligible for inclusion. A total of 20 articles were selected for this review. DATA SYNTHESIS: Most studies reported carbohydrate malabsorption, particularly lactose malabsorption, and suggested an increase in diarrhea and reduced weight gain in children on a lactose-containing diet. As most studies reviewed were observational, there was no conclusive scientific evidence of a causal relationship between lactose malabsorption and a worse clinical outcome among malnourished children. CONCLUSION: The combined data indicate that carbohydrate malabsorption is prevalent in children with SAM. Additional well-designed intervention studies are needed to determine whether outcomes of SAM complicated by carbohydrate malabsorption could be improved by altering the carbohydrate/lactose content of therapeutic feeds and to elucidate the precise mechanisms involved.

Landais E, Huang X, Havenar-Daughton C, Murrell B, Price MA, Wickramasinghe L, Ramos A, Bian CB, Simek M, Allen S et al. 2016. Broadly Neutralizing Antibody Responses in a Large Longitudinal Sub-Saharan HIV Primary Infection Cohort. PLoS Pathog, 12 (1), pp. e1005369. | Citations: 56 (Web of Science Lite) | Show Abstract | Read more

Broadly neutralizing antibodies (bnAbs) are thought to be a critical component of a protective HIV vaccine. However, designing vaccines immunogens able to elicit bnAbs has proven unsuccessful to date. Understanding the correlates and immunological mechanisms leading to the development of bnAb responses during natural HIV infection is thus critical to the design of a protective vaccine. The IAVI Protocol C program investigates a large longitudinal cohort of primary HIV-1 infection in Eastern and South Africa. Development of neutralization was evaluated in 439 donors using a 6 cross-clade pseudo-virus panel predictive of neutralization breadth on larger panels. About 15% of individuals developed bnAb responses, essentially between year 2 and year 4 of infection. Statistical analyses revealed no influence of gender, age or geographical origin on the development of neutralization breadth. However, cross-clade neutralization strongly correlated with high viral load as well as with low CD4 T cell counts, subtype-C infection and HLA-A*03(-) genotype. A correlation with high overall plasma IgG levels and anti-Env IgG binding titers was also found. The latter appeared not associated with higher affinity, suggesting a greater diversity of the anti-Env responses in broad neutralizers. Broadly neutralizing activity targeting glycan-dependent epitopes, largely the N332-glycan epitope region, was detected in nearly half of the broad neutralizers while CD4bs and gp41-MPER bnAb responses were only detected in very few individuals. Together the findings suggest that both viral and host factors are critical for the development of bnAbs and that the HIV Env N332-glycan supersite may be a favorable target for vaccine design.

Abdi AI, Warimwe GM, Muthui MK, Kivisi CA, Kiragu EW, Fegan GW, Bull PC. 2016. Global selection of Plasmodium falciparum virulence antigen expression by host antibodies. Sci Rep, 6 (1), pp. 19882. | Citations: 10 (Scopus) | Show Abstract | Read more

Parasite proteins called PfEMP1 that are inserted on the surface of infected erythrocytes, play a key role in the severe pathology associated with infection by the Plasmodium falciparum malaria parasite. These proteins mediate binding of infected cells to the endothelial lining of blood vessels as a strategy to avoid clearance by the spleen and are major targets of naturally acquired immunity. PfEMP1 is encoded by a large multi-gene family called var. Mutually-exclusive transcriptional switching between var genes allows parasites to escape host antibodies. This study examined in detail the patterns of expression of var in a well-characterized sample of parasites from Kenyan Children. Instead of observing clear inverse relationships between the expression of broad sub-classes of PfEMP1, we found that expression of different PfEMP1 groups vary relatively independently. Parasite adaptation to host antibodies also appears to involve a general reduction in detectable var gene expression. We suggest that parasites switch both between different PfEMP1 variants and between high and low expression states. Such a strategy could provide a means of avoiding immunological detection and promoting survival under high levels of host immunity.

Kyaw SS, Drake T, Thi A, Kyaw MP, Hlaing T, Smithuis FM, White LJ, Lubell Y. 2016. Malaria community health workers in Myanmar: a cost analysis. Malar J, 15 (1), pp. 41. | Citations: 7 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Myanmar has the highest malaria incidence and attributed mortality in South East Asia with limited healthcare infrastructure to manage this burden. Establishing malaria Community Health Worker (CHW) programmes is one possible strategy to improve access to malaria diagnosis and treatment, particularly in remote areas. Despite considerable donor support for implementing CHW programmes in Myanmar, the cost implications are not well understood. METHODS: An ingredients based micro-costing approach was used to develop a model of the annual implementation cost of malaria CHWs in Myanmar. A cost model was constructed based on activity centres comprising of training, patient malaria services, monitoring and supervision, programme management, overheads and incentives. The model takes a provider perspective. Financial data on CHWs programmes were obtained from the 2013 financial reports of the Three Millennium Development Goal fund implementing partners that have been working on malaria control and elimination in Myanmar. Sensitivity and scenario analyses were undertaken to outline parameter uncertainty and explore changes to programme cost for key assumptions. RESULTS: The range of total annual costs for the support of one CHW was US$ 966-2486. The largest driver of CHW cost was monitoring and supervision (31-60% of annual CHW cost). Other important determinants of cost included programme management (15-28% of annual CHW cost) and patient services (6-12% of annual CHW cost). Within patient services, malaria rapid diagnostic tests are the major contributor to cost (64% of patient service costs). CONCLUSION: The annual cost of a malaria CHW in Myanmar varies considerably depending on the context and the design of the programme, in particular remoteness and the approach to monitoring and evaluation. The estimates provide information to policy makers and CHW programme planners in Myanmar as well as supporting economic evaluations of their cost-effectiveness.

Chen I, Clarke SE, Gosling R, Hamainza B, Killeen G, Magill A, O'Meara W, Price RN, Riley EM. 2016. "Asymptomatic" Malaria: A Chronic and Debilitating Infection That Should Be Treated. PLoS Med, 13 (1), pp. e1001942. | Citations: 29 (Web of Science Lite) | Read more

English M, Karumbi J, Maina M, Aluvaala J, Gupta A, Zwarenstein M, Opiyo N. 2016. The need for pragmatic clinical trials in low and middle income settings - taking essential neonatal interventions delivered as part of inpatient care as an illustrative example. BMC Med, 14 (1), pp. 5. | Citations: 1 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Pragmatic randomized trials aim to examine the effects of interventions in the full spectrum of patients seen by clinicians who receive routine care. Such trials should be employed in parallel with efforts to implement many interventions which appear promising but where evidence of effectiveness is limited. We illustrate this need taking the case of essential interventions to reduce inpatient neonatal mortality in low and middle income countries (LMIC) but suggest the arguments are applicable in most clinical areas. DISCUSSION: A set of basic interventions have been defined, based on available evidence, that could substantially reduce early neonatal deaths if successfully implemented at scale within district and sub-district hospitals in LMIC. However, we illustrate that there remain many gaps in the evidence available to guide delivery of many inpatient neonatal interventions, that existing evidence is often from high income settings and that it frequently indicates uncertainty in the magnitude or even direction of estimates of effect. Furthermore generalizing results to LMIC where conditions include very high patient staff ratios, absence of even basic technologies, and a reliance on largely empiric management is problematic. Where there is such uncertainty over the effectiveness of interventions in different contexts or in the broad populations who might receive the intervention in routine care settings pragmatic trials that preserve internal validity while promoting external validity should be increasingly employed. Many interventions are introduced without adequate evidence of their effectiveness in the routine settings to which they are introduced. Global efforts are needed to support pragmatic research to establish the effectiveness in routine care of many interventions intended to reduce mortality or morbidity in LMIC. Such research should be seen as complementary to efforts to optimize implementation.

Phu VD, Wertheim HFL, Larsson M, Nadjm B, Dinh Q-D, Nilsson LE, Rydell U, Le TTD, Trinh SH, Pham HM et al. 2016. Burden of Hospital Acquired Infections and Antimicrobial Use in Vietnamese Adult Intensive Care Units. PLoS One, 11 (1), pp. e0147544. | Citations: 13 (Scopus) | Show Abstract | Read more

BACKGROUND: Vietnam is a lower middle-income country with no national surveillance system for hospital-acquired infections (HAIs). We assessed the prevalence of hospital-acquired infections and antimicrobial use in adult intensive care units (ICUs) across Vietnam. METHODS: Monthly repeated point prevalence surveys were systematically conducted to assess HAI prevalence and antimicrobial use in 15 adult ICUs across Vietnam. Adults admitted to participating ICUs before 08:00 a.m. on the survey day were included. RESULTS: Among 3287 patients enrolled, the HAI prevalence was 29.5% (965/3266 patients, 21 missing). Pneumonia accounted for 79.4% (804/1012) of HAIs Most HAIs (84.5% [855/1012]) were acquired in the survey hospital with 42.5% (363/855) acquired prior to ICU admission and 57.5% (492/855) developed during ICU admission. In multivariate analysis, the strongest risk factors for HAI acquired in ICU were: intubation (OR 2.76), urinary catheter (OR 2.12), no involvement of a family member in patient care (OR 1.94), and surgery after admission (OR 1.66). 726 bacterial isolates were cultured from 622/1012 HAIs, most frequently Acinetobacter baumannii (177/726 [24.4%]), Pseudomonas aeruginosa (100/726 [13.8%]), and Klebsiella pneumoniae (84/726 [11.6%]), with carbapenem resistance rates of 89.2%, 55.7%, and 14.9% respectively. Antimicrobials were prescribed for 84.8% (2787/3287) patients, with 73.7% of patients receiving two or more. The most common antimicrobial groups were third generation cephalosporins, fluoroquinolones, and carbapenems (20.1%, 19.4%, and 14.1% of total antimicrobials, respectively). CONCLUSION: A high prevalence of HAIs was observed, mainly caused by Gram-negative bacteria with high carbapenem resistance rates. This in combination with a high rate of antimicrobial use illustrates the urgent need to improve rational antimicrobial use and infection control efforts.

Warimwe GM, Gesharisha J, Carr BV, Otieno S, Otingah K, Wright D, Charleston B, Okoth E, Elena L-G, Lorenzo G et al. 2016. Chimpanzee Adenovirus Vaccine Provides Multispecies Protection against Rift Valley Fever. Sci Rep, 6 (1), pp. 20617. | Citations: 19 (Web of Science Lite) | Show Abstract | Read more

Rift Valley Fever virus (RVFV) causes recurrent outbreaks of acute life-threatening human and livestock illness in Africa and the Arabian Peninsula. No licensed vaccines are currently available for humans and those widely used in livestock have major safety concerns. A 'One Health' vaccine development approach, in which the same vaccine is co-developed for multiple susceptible species, is an attractive strategy for RVFV. Here, we utilized a replication-deficient chimpanzee adenovirus vaccine platform with an established human and livestock safety profile, ChAdOx1, to develop a vaccine for use against RVFV in both livestock and humans. We show that single-dose immunization with ChAdOx1-GnGc vaccine, encoding RVFV envelope glycoproteins, elicits high-titre RVFV-neutralizing antibody and provides solid protection against RVFV challenge in the most susceptible natural target species of the virus-sheep, goats and cattle. In addition we demonstrate induction of RVFV-neutralizing antibody by ChAdOx1-GnGc vaccination in dromedary camels, further illustrating the potency of replication-deficient chimpanzee adenovirus vaccine platforms. Thus, ChAdOx1-GnGc warrants evaluation in human clinical trials and could potentially address the unmet human and livestock vaccine needs.

Zhu L, Mok S, Imwong M, Jaidee A, Russell B, Nosten F, Day NP, White NJ, Preiser PR, Bozdech Z. 2016. New insights into the Plasmodium vivax transcriptome using RNA-Seq. Sci Rep, 6 (1), pp. 20498. | Citations: 6 (Scopus) | Show Abstract | Read more

Historically seen as a benign disease, it is now becoming clear that Plasmodium vivax can cause significant morbidity. Effective control strategies targeting P. vivax malaria is hindered by our limited understanding of vivax biology. Here we established the P. vivax transcriptome of the Intraerythrocytic Developmental Cycle (IDC) of two clinical isolates in high resolution by Illumina HiSeq platform. The detailed map of transcriptome generates new insights into regulatory mechanisms of individual genes and reveals their intimate relationship with specific biological functions. A transcriptional hotspot of vir genes observed on chromosome 2 suggests a potential active site modulating immune evasion of the Plasmodium parasite across patients. Compared to other eukaryotes, P. vivax genes tend to have unusually long 5' untranslated regions and also present multiple transcription start sites. In contrast, alternative splicing is rare in P. vivax but its association with the late schizont stage suggests some of its significance for gene function. The newly identified transcripts, including up to 179 vir like genes and 3018 noncoding RNAs suggest an important role of these gene/transcript classes in strain specific transcriptional regulation.

Phommasone K, Althaus T, Souvanthong P, Phakhounthong K, Soyvienvong L, Malapheth P, Mayxay M, Pavlicek RL, Paris DH, Dance D et al. 2016. Accuracy of commercially available c-reactive protein rapid tests in the context of undifferentiated fevers in rural Laos. BMC Infect Dis, 16 (1), pp. 61. | Citations: 2 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: C-Reactive Protein (CRP) has been shown to be an accurate biomarker for discriminating bacterial from viral infections in febrile patients in Southeast Asia. Here we investigate the accuracy of existing rapid qualitative and semi-quantitative tests as compared with a quantitative reference test to assess their potential for use in remote tropical settings. METHODS: Blood samples were obtained from consecutive patients recruited to a prospective fever study at three sites in rural Laos. At each site, one of three rapid qualitative or semi-quantitative tests was performed, as well as a corresponding quantitative NycoCard Reader II as a reference test. We estimate the sensitivity and specificity of the three tests against a threshold of 10 mg/L and kappa values for the agreement of the two semi-quantitative tests with the results of the reference test. RESULTS: All three tests showed high sensitivity, specificity and kappa values as compared with the NycoCard Reader II. With a threshold of 10 mg/L the sensitivity of the tests ranged from 87-98 % and the specificity from 91-98 %. The weighted kappa values for the semi-quantitative tests were 0.7 and 0.8. CONCLUSION: The use of CRP rapid tests could offer an inexpensive and effective approach to improve the targeting of antibiotics in remote settings where health facilities are basic and laboratories are absent. This study demonstrates that accurate CRP rapid tests are commercially available; evaluations of their clinical impact and cost-effectiveness at point of care is warranted.

Espino FE, Bibit J-A, Sornillo JB, Tan A, von Seidlein L, Ley B. 2016. Comparison of Three Screening Test Kits for G6PD Enzyme Deficiency: Implications for Its Use in the Radical Cure of Vivax Malaria in Remote and Resource-Poor Areas in the Philippines. PLoS One, 11 (2), pp. e0148172. | Citations: 12 (Scopus) | Show Abstract | Read more

OBJECTIVE: We evaluated a battery of Glucose-6-Phosphate Dehydrogenase diagnostic point-of-care tests (PoC) to assess the most suitable product in terms of performance and operational characteristics for remote areas. METHODS: Samples were collected in Puerto Princesa City, Palawan, Philippines and tested for G6PD deficiency with a fluorescent spot test (FST; Procedure 203, Trinity Biotech, Ireland), the semiquantitative WST8/1-methoxy PMS (WST; Dojindo, Japan) and the Carestart G6PD Rapid Diagnostic Test (CSG; AccessBio, USA). Results were compared to spectrophotometry (Procedure 345, Trinity Biotech, Ireland). Sensitivity and specificity were calculated for each test with cut-off activities of 10%, 20%, 30% and 60% of the adjusted male median. RESULTS: The adjusted male median was 270.5 IU/10(12) RBC. FST and WST were tested on 621 capillary blood samples, the CSG was tested on venous and capillary blood on 302 samples. At 30% G6PD activity, sensitivity for the FST was between 87.7% (95%CI: 76.8% to 93.9%) and 96.5% (95%CI: 87.9% to 99.5%) depending on definition of intermediate results; the WST was 84.2% (95%CI: 72.1% to 92.5%); and the CSG was between 68.8% (95%CI: 41.3% to 89.0%) and 93.8% (95%CI: 69.8% to 99.8%) when the test was performed on capillary or venous blood respectively. Sensitivity of FST and CSG (tested with venous blood) were comparable (p>0.05). The analysis of venous blood samples by the CSG yielded significantly higher results than FST and CSG performed on capillary blood (p<0.05). Sensitivity of the CSG varied depending on source of blood used (p<0.05). CONCLUSION: The operational characteristics of the CSG were superior to all other test formats. Performance and operational characteristics of the CSG performed on venous blood suggest the test to be a good alternative to the FST.

Ponsuwanna P, Kochakarn T, Bunditvorapoom D, Kümpornsin K, Otto TD, Ridenour C, Chotivanich K, Wilairat P, White NJ, Miotto O, Chookajorn T. 2016. Comparative genome-wide analysis and evolutionary history of haemoglobin-processing and haem detoxification enzymes in malarial parasites. Malar J, 15 (1), pp. 51. | Citations: 3 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Malaria parasites have evolved a series of intricate mechanisms to survive and propagate within host red blood cells. Intra-erythrocytic parasitism requires these organisms to digest haemoglobin and detoxify iron-bound haem. These tasks are executed by haemoglobin-specific proteases and haem biocrystallization factors that are components of a large multi-subunit complex. Since haemoglobin processing machineries are functionally and genetically linked to the modes of action and resistance mechanisms of several anti-malarial drugs, an understanding of their evolutionary history is important for drug development and drug resistance prevention. METHODS: Maximum likelihood trees of genetic repertoires encoding haemoglobin processing machineries within Plasmodium species, and with the representatives of Apicomplexan species with various host tropisms, were created. Genetic variants were mapped onto existing three-dimensional structures. Genome-wide single nucleotide polymorphism data were used to analyse the selective pressure and the effect of these mutations at the structural level. RESULTS: Recent expansions in the falcipain and plasmepsin repertoires are unique to human malaria parasites especially in the Plasmodium falciparum and P. reichenowi lineage. Expansion of haemoglobin-specific plasmepsins occurred after the separation event of Plasmodium species, but the other members of the plasmepsin family were evolutionarily conserved with one copy for each sub-group in every Apicomplexan species. Haemoglobin-specific falcipains are separated from invasion-related falcipain, and their expansions within one specific locus arose independently in both P. falciparum and P. vivax lineages. Gene conversion between P. falciparum falcipain 2A and 2B was observed in artemisinin-resistant strains. Comparison between the numbers of non-synonymous and synonymous mutations suggests a strong selective pressure at falcipain and plasmepsin genes. The locations of amino acid changes from non-synonymous mutations mapped onto protein structures revealed clusters of amino acid residues in close proximity or near the active sites of proteases. CONCLUSION: A high degree of polymorphism at the haemoglobin processing genes implicates an imposition of selective pressure. The identification in recent years of functional redundancy of haemoglobin-specific proteases makes them less appealing as potential drug targets, but their expansions, especially in the human malaria parasite lineages, unequivocally point toward their functional significance during the independent and repetitive adaptation events in malaria parasite evolutionary history.

Tobgay T, Samdrup P, Jamtsho T, Mannion K, Ortega L, Khamsiriwatchara A, Price RN, Thriemer K, Kaewkungwal J. 2016. Performance and user acceptance of the Bhutan febrile and malaria information system: report from a pilot study. Malar J, 15 (1), pp. 52. | Show Abstract | Read more

BACKGROUND: Over the last decade, Bhutan has made substantial progress in controlling malaria. The country is now in an elimination phase, aiming to achieve no locally transmitted malaria by 2018. However, challenges remain and innovative control strategies are needed to overcome these. The evaluation and user acceptance of a robust surveillance tool applicable for informing malaria elimination activities is reported here. METHODS: The Bhutan Febrile and Malaria Information System (BFMIS) is a combination of web-based and mobile technology that captures malariometric surveillance data and generates real time reports. The system was rolled out at six sites and data uploaded regularly for analysis. Data completeness, accuracy and data turnaround time were accessed by comparison to traditional paper based surveillance records. User acceptance and willingness for further roll out was assessed using qualitative and quantitative data. RESULTS: Data completeness was nearly 10 % higher using the electronic system than the paper logs, and accuracy and validity of both approaches was comparable (up to 0.05 % in valid data and up to 3.06 % inaccurate data). Data turnaround time was faster using the BFMIS. General user satisfaction with the BFMIS was high, with high willingness of health facilities to adopt the system. Qualitative interviews revealed several areas for improvement before scale up. CONCLUSIONS: The BFMIS had numerous advantages over the paper-based system and based on the findings of the survey the Vector-Borne Disease Control Programme has taken the decision to incorporate the BMFIS and expand its use throughout all areas at risk for malaria as a key surveillance tool.

Karuri SW, Snow RW. 2016. Forecasting paediatric malaria admissions on the Kenya Coast using rainfall. Glob Health Action, 9 (1), pp. 29876. | Citations: 1 (Scopus) | Show Abstract | Read more

BACKGROUND: Malaria is a vector-borne disease which, despite recent scaled-up efforts to achieve control in Africa, continues to pose a major threat to child survival. The disease is caused by the protozoan parasite Plasmodium and requires mosquitoes and humans for transmission. Rainfall is a major factor in seasonal and secular patterns of malaria transmission along the East African coast. OBJECTIVE: The goal of the study was to develop a model to reliably forecast incidences of paediatric malaria admissions to Kilifi District Hospital (KDH). DESIGN: In this article, we apply several statistical models to look at the temporal association between monthly paediatric malaria hospital admissions, rainfall, and Indian Ocean sea surface temperatures. Trend and seasonally adjusted, marginal and multivariate, time-series models for hospital admissions were applied to a unique data set to examine the role of climate, seasonality, and long-term anomalies in predicting malaria hospital admission rates and whether these might become more or less predictable with increasing vector control. RESULTS: The proportion of paediatric admissions to KDH that have malaria as a cause of admission can be forecast by a model which depends on the proportion of malaria admissions in the previous 2 months. This model is improved by incorporating either the previous month's Indian Ocean Dipole information or the previous 2 months' rainfall. CONCLUSIONS: Surveillance data can help build time-series prediction models which can be used to anticipate seasonal variations in clinical burdens of malaria in stable transmission areas and aid the timing of malaria vector control.

Warrell DA. 2016. Venomous animals Medicine, 44 (2), pp. 120-124. | Show Abstract | Read more

© 2015 Elsevier Ltd. All rights reserved. Every year, snake-bites kill more than 100,000 people, while survivors suffer physical and mental sequelae; insects cause over 5000 anaphylactic deaths, scorpion-stings kill more than 1000 and spiders and jellyfish kill hundreds. Aquatic venomous animals include sea-snakes, fish, jellyfish, corals, cone shells, blue-ringed octopuses and sea urchins. Specific antidotes - hyperimmune serum antivenoms - are manufactured for serious envenoming. Adrenaline (epinephrine) is essential treatment for anaphylaxis. Cardiorespiratory and kidney failure require supportive treatment. Surgical intervention is rarely needed. Prevention is all important; community education can reduce risk by encouraging the use of protective clothing, lights after dark, bed nets and urgent medical treatment rather than traditional remedies.

De Beaudrap P, Turyakira E, Nabasumba C, Tumwebaze B, Piola P, Boum Ii Y, McGready R. 2016. Timing of malaria in pregnancy and impact on infant growth and morbidity: a cohort study in Uganda. Malar J, 15 (1), pp. 92. | Citations: 3 (Scopus) | Show Abstract | Read more

BACKGROUND: Malaria in pregnancy (MiP) is a major cause of fetal growth restriction and low birth weight in endemic areas of sub-Saharan Africa. Understanding of the impact of MiP on infant growth and infant risk of malaria or morbidity is poorly characterized. The objective of this study was to describe the impact of MIP on subsequent infant growth, malaria and morbidity. METHODS: Between 2006 and 2009, 82 % (832/1018) of pregnant women with live-born singletons and ultrasound determined gestational age were enrolled in a prospective cohort with active weekly screening and treatment for malaria. Infants were followed monthly for growth and morbidity and received active monthly screening and treatment for malaria during their first year of life. Multivariate analyses were performed to analyse the association between malaria exposure during pregnancy and infants' growth, malaria infections, diarrhoea episodes and acute respiratory infections. RESULTS: Median time of infant follow-up was 12 months and infants born to a mother who had MiP were at increased risk of impaired height and weight gain (-2.71 cm, 95 % CI -4.17 to -1.25 and -0.42 kg, 95 % CI -0.76 to -0.08 at 12 months for >1 MiP compared to no MiP) and of malaria infection (relative risk 10.42, 95 % CI 2.64-41.10 for infants born to mothers with placental malaria). The risks of infant growth restriction and infant malaria infection were maximal when maternal malaria occurred in the 12 weeks prior to delivery. Recurrent MiP was also associated with acute respiratory infection (RR 1.96, 95 % CI 1.25-3.06) and diarrhoea during infancy (RR 1.93, 95 % CI 1.02-3.66). CONCLUSION: This study shows that despite frequent active screening and prompt treatment of MiP, impaired growth and an increased risk of malaria and non-malaria infections can be observed in the infants. Effective preventive measures in pregnancy remain a research priority. This study was registered with, number NCT00495508.

Qui PT, Khanh TH, Trieu HT, Giang PT, Bich NN, Thoa LPK, Nhan LNT, Sabanathan S, Van Doorn R, Toan ND et al. 2016. Intravenous magnesium sulfate for the management of severe hand, foot, and mouth disease with autonomic nervous system dysregulation in Vietnamese children: study protocol for a randomized controlled trial. Trials, 17 (1), pp. 98. | Citations: 1 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Over the last 15 years, hand, foot, and mouth disease (HFMD) has emerged as a major public health burden across the Asia-Pacific region. A small proportion of HFMD patients, typically those infected with enterovirus 71 (EV71), develop brainstem encephalitis with autonomic nervous system (ANS) dysregulation and may progress rapidly to cardiopulmonary failure and death. Although milrinone has been reported to control hypertension and support myocardial function in two small studies, in practice, a number of children still deteriorate despite this treatment. Magnesium sulfate (MgSO4) is a cheap, safe, and readily available medication that is effective in managing tetanus-associated ANS dysregulation and has shown promise when used empirically in EV71-confirmed severe HFMD cases. METHODS/DESIGN: We describe the protocol for a randomized, placebo-controlled, double-blind trial of intravenous MgSO4 in Vietnamese children diagnosed clinically with HFMD plus ANS dysregulation with systemic hypertension. A loading dose of MgSO4 or identical placebo is given over 20 min followed by a maintenance infusion for 72 h according to response, aiming for Mg levels two to three times the normal level in the treatment arm. The primary endpoint is a composite of disease progression within 72 h defined as follows: development of pre-specified blood pressure criteria necessitating the addition of milrinone, the need for ventilation, shock, or death. Secondary endpoints comprise these parameters singly, plus other clinical endpoints including the following: requirement for other inotropic agents; duration of hospitalization; presence of neurological sequelae at discharge in survivors; and neurodevelopmental status assessed 6 months after discharge. The number and severity of adverse events observed in the two treatment arms will also be compared. Based on preliminary data from a case series, and allowing for some losses, 190 patients (95 in each arm) will allow detection of a 50 % reduction in disease progression with 90 % power at a two-sided 5 % significance level. DISCUSSION: Given the large numbers of HFMD cases currently being seen in hospitals in Asia, if MgSO4 is shown to be effective in controlling ANS dysregulation and preventing severe HFMD complications, this finding would be important to pediatric care throughout the region. TRIAL REGISTRATION: Identifier: NCT01940250 (Registered 22 August 2013).

Birgersson S, Van Toi P, Truong NT, Dung NT, Ashton M, Hien TT, Abelö A, Tarning J. 2016. Population pharmacokinetic properties of artemisinin in healthy male Vietnamese volunteers. Malar J, 15 (1), pp. 90. | Citations: 1 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Artemisinin-based combination therapy is recommended as first-line anti-malarial treatment worldwide. A combination of artemisinin with the long acting drug piperaquine has shown high efficacy and tolerability in patients with uncomplicated Plasmodium falciparum infections. The aim of this study was to characterize the population pharmacokinetic properties of artemisinin in healthy male Vietnamese volunteers after two different dose sizes, formulations and in a combination with piperaquine. A secondary aim was to compare two different methods for the evaluation of bioequivalence of the formulations. METHODS: Fifteen subjects received four different dose regimens of a single dose of artemisinin as a conventional formulation (160 and 500 mg) and as a micronized test formulation (160 mg alone and in combination with piperaquine phosphate, 360 mg) with a washout period of 3 weeks between each period (i.e. four-way cross-over). Venous plasma samples were collected frequently up to 12 h after dose in each period. Artemisinin was quantified in plasma using liquid chromatography coupled with tandem mass spectrometry. A nonlinear mixed-effects modelling approach was utilized to evaluate the population pharmacokinetic properties of the drug and to investigate the clinical impact of different formulations. RESULTS: The plasma concentration-time profiles for artemisinin were adequately described by a transit-absorption model with a one-compartment disposition, in all four sequences simultaneously. The mean oral clearance, volume of distribution and terminal elimination half-life was 417 L/h, 1210 L and 1.93 h, respectively. Influence of formulation, dose and possible interaction of piperaquine was evaluated as categorical covariates in full covariate approaches. No clinically significant differences between formulations were shown which was in accordance with the previous results using a non-compartmental bioequivalence approach. CONCLUSIONS: This is the first population pharmacokinetic characterization of artemisinin in healthy volunteers. Increasing the dose resulted in a significant increase in the mean transit-time but the micronized formulation or concomitant piperaquine administration did not affect the pharmacokinetic properties of artemisinin. The results from the traditional bioequivalence evaluation were comparable with results obtained from mixed-effects modelling.

Paudyal B, Paudel K, Shakya M, Basnyat B. 2016. Paradoxical reaction to antitubercular treatment in a case of pulmonary tuberculosis. BMJ Case Rep, 2016 pp. bcr2015214285-bcr2015214285. | Show Abstract | Read more

A 51-year-old man presented with intermittent fever, mild cough and loss of appetite of 1-month duration. His sputum smear was positive for acid-fast bacilli and his chest radiograph revealed apical infiltrations. The patient was treated with antitubercular therapy (ATT), recovered and was well for 1 month, after which he suddenly developed focal seizures. MRI of the brain with gadolinium enhancement showed high intensity nodular foci in the frontal, parietal and occipital regions. The patient was diagnosed as a case of paradoxical reaction to ATT, and was successfully managed with continued ATT and adjunctive steroid therapy.

Dicko A, Brown JM, Diawara H, Baber I, Mahamar A, Soumare HM, Sanogo K, Koita F, Keita S, Traore SF et al. 2016. Primaquine to reduce transmission of Plasmodium falciparum malaria in Mali: a single-blind, dose-ranging, adaptive randomised phase 2 trial. Lancet Infect Dis, 16 (6), pp. 674-684. | Citations: 25 (Scopus) | Show Abstract | Read more

BACKGROUND: Single low doses of primaquine, when added to artemisinin-based combination therapy, might prevent transmission of Plasmodium falciparum malaria to mosquitoes. We aimed to establish the activity and safety of four low doses of primaquine combined with dihydroartemisinin-piperaquine in male patients in Mali. METHODS: In this phase 2, single-blind, dose-ranging, adaptive randomised trial, we enrolled boys and men with uncomplicated P falciparum malaria at the Malaria Research and Training Centre (MRTC) field site in Ouelessebougou, Mali. All participants were confirmed positive carriers of gametocytes through microscopy and had normal function of glucose-6-phosphate dehydrogenase (G6PD) on colorimetric quantification. In the first phase, participants were randomly assigned (1:1:1) to one of three primaquine doses: 0 mg/kg (control), 0·125 mg/kg, and 0·5 mg/kg. Randomisation was done with a computer-generated randomisation list (in block sizes of six) and concealed with sealed, opaque envelopes. In the second phase, different participants were sequentially assigned (1:1) to 0·25 mg/kg primaquine or 0·0625 mg/kg primaquine. Primaquine tablets were dissolved into a solution and administered orally in a single dose. Participants were also given a 3 day course of dihydroartemisinin-piperaquine, administered by weight (320 mg dihydroartemisinin and 40 mg piperaquine per tablet). Outcome assessors were masked to treatment allocation, but participants were permitted to find out group assignment. Infectivity was assessed through membrane-feeding assays, which were optimised through the beginning part of phase one. The primary efficacy endpoint was the mean within-person percentage change in mosquito infectivity 2 days after primaquine treatment in participants who completed the study after optimisation of the infectivity assay, had both a pre-treatment infectivity measurement and at least one follow-up infectivity measurement, and who were given the correct primaquine dose. The safety endpoint was the mean within-person change in haemoglobin concentration during 28 days of study follow-up in participants with at least one follow-up visit. This study is registered with, number NCT01743820. FINDINGS: Between Jan 2, 2013, and Nov 27, 2014, we enrolled 81 participants. In the primary analysis sample (n=71), participants in the 0·25 mg/kg primaquine dose group (n=15) and 0·5 mg/kg primaquine dose group (n=14) had significantly lower mean within-person reductions in infectivity at day 2-92·6% (95% CI 78·3-100; p=0·0014) for the 0·25 mg/kg group; and 75·0% (45·7-100; p=0·014) for the 0·5 mg/kg primaquine group-compared with those in the control group (n=14; 11·3% [-27·4 to 50·0]). Reductions were not significantly different from control for participants assigned to the 0·0625 mg/kg dose group (n=16; 41·9% [1·4-82·5]; p=0·16) and the 0·125 mg/kg dose group (n=12; 54·9% [13·4-96·3]; p=0·096). No clinically meaningful or statistically significant drops in haemoglobin were recorded in any individual in the haemoglobin analysis (n=70) during follow-up. No serious adverse events were reported and adverse events did not differ between treatment groups. INTERPRETATION: A single dose of 0·25 mg/kg primaquine, given alongside dihydroartemisinin-piperaquine, was safe and efficacious for the prevention of P falciparum malaria transmission in boys and men who are not deficient in G6PD. Future studies should assess the safety of single-dose primaquine in G6PD-deficient individuals to define the therapeutic range of primaquine to enable the safe roll-out of community interventions with primaquine. FUNDING: Bill & Melinda Gates Foundation.

Fresnay S, McArthur MA, Magder L, Darton TC, Jones C, Waddington CS, Blohmke CJ, Angus B, Levine MM, Pollard AJ, Sztein MB. 2016. Salmonella Typhi-specific multifunctional CD8+ T cells play a dominant role in protection from typhoid fever in humans. J Transl Med, 14 (1), pp. 62. | Citations: 13 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Typhoid fever, caused by the human-restricted organism Salmonella Typhi (S. Typhi), is a major public health problem worldwide. Development of novel vaccines remains imperative, but is hampered by an incomplete understanding of the immune responses that correlate with protection. METHODS: Recently, a controlled human infection model was re-established in which volunteers received ~10(3) cfu wild-type S. Typhi (Quailes strain) orally. Twenty-one volunteers were evaluated for their cell-mediated immune (CMI) responses. Ex vivo PBMC isolated before and up to 1 year after challenge were exposed to three S. Typhi-infected targets, i.e., autologous B lymphoblastoid cell-lines (B-LCL), autologous blasts and HLA-E restricted AEH B-LCL cells. CMI responses were evaluated using 14-color multiparametric flow cytometry to detect simultaneously five intracellular cytokines/chemokines (i.e., IL-17A, IL-2, IFN-g, TNF-a and MIP-1b) and a marker of degranulation/cytotoxic activity (CD107a). RESULTS: Herein we provide the first evidence that S. Typhi-specific CD8+ responses correlate with clinical outcome in humans challenged with wild-type S. Typhi. Higher multifunctional S. Typhi-specific CD8+ baseline responses were associated with protection against typhoid and delayed disease onset. Moreover, following challenge, development of typhoid fever was accompanied by decreases in circulating S. Typhi-specific CD8+ T effector/memory (TEM) with gut homing potential, suggesting migration to the site(s) of infection. In contrast, protection against disease was associated with low or no changes in circulating S. Typhi-specific TEM. CONCLUSIONS: These studies provide novel insights into the protective immune responses against typhoid disease that will aid in selection and development of new vaccine candidates.

Awab GR, Imwong M, Pukrittayakamee S, Alim F, Hanpithakpong W, Tarning J, Dondorp AM, Day NPJ, White NJ, Woodrow CJ. 2016. Clinical trials of artesunate plus sulfadoxine-pyrimethamine for Plasmodium falciparum malaria in Afghanistan: maintained efficacy a decade after introduction. Malar J, 15 (1), pp. 121. | Citations: 4 (Scopus) | Show Abstract | Read more

BACKGROUND: Combination therapy with artesunate plus sulfadoxine-pyrimethamine (SP) was adopted as recommended treatment for Plasmodium falciparum infection in Afghanistan in 2003. METHODS: A series of prospective clinical studies examining the efficacy of artesunate plus sulfadoxine-pyrimethamine (AS + SP) against P. falciparum were undertaken in sentinel sites in Afghanistan from 2007 to 2014, accompanied by relevant molecular studies. The first study was a randomized trial of AS + SP versus dihydroartemisinin-piperaquine, while two subsequent studies were standard therapeutic efficacy studies of AS + SP. RESULTS: Three hundred and three patients were enrolled across four provinces in the north and east of the country. Curative efficacy was high in all the trials, with an adequate clinical and parasitological response (ACPR) of more than 95 % in all groups and trial stages. Genotyping for drug-resistance alleles at dhfr indicated fixation of the S108 N mutation and a prevalence of the C59R mutation of approximately 95 % across all sites. Other mutations in dhfr and dhps remained rare or absent entirely, although five isolates from the first trial carried the dhps triple mutant SGEGA haplotype. In the last study undertaken in 2012-2014 the K13 artemisinin resistance marker was examined; only two of 60 successfully sequenced samples carried a K13-propeller mutation. CONCLUSIONS: These data confirm maintained efficacy 10 years after introduction of artesunate plus SP as combination treatment of P. falciparum in Afghanistan. The molecular data indicate that despite a substantial fall in incidence, resistance has not developed to artemisinins, or intensified to the ACT partner drug components. Trial Registration NCT00682578, NCT01115439 and NCT01707199.

Win AA, Imwong M, Kyaw MP, Woodrow CJ, Chotivanich K, Hanboonkunupakarn B, Pukrittayakamee S. 2016. K13 mutations and pfmdr1 copy number variation in Plasmodium falciparum malaria in Myanmar. Malar J, 15 (1), pp. 110. | Citations: 8 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Artemisinin-based combination therapy has been first-line treatment for falciparum malaria in Myanmar since 2005. The wide extent of artemisinin resistance in the Greater Mekong sub-region and the presence of mefloquine resistance at the Myanmar-Thailand border raise concerns over resistance patterns in Myanmar. The availability of molecular markers for resistance to both drugs enables assessment even in remote malaria-endemic areas. METHODS: A total of 250 dried blood spot samples collected from patients with Plasmodium falciparum malarial infection in five malaria-endemic areas across Myanmar were analysed for kelch 13 sequence (k13) and pfmdr1 copy number variation. K13 mutations in the region corresponding to amino acids 210-726 (including the propeller region of the protein) were detected by nested PCR amplification and sequencing, and pfmdr1 copy number variation by real-time PCR. In two sites, a sub-set of patients were prospectively followed up for assessment of day-3 parasite clearance rates after a standard course of artemether-lumefantrine. RESULTS: K13 mutations and pfmdr1 amplification were successfully analysed in 206 and 218 samples, respectively. Sixty-nine isolates (33.5 %) had mutations within the k13 propeller region with 53 of these (76.8 %) having mutations already known to be associated with artemisinin resistance. F446I (32 isolates) and P574L (15 isolates) were the most common examples. K13 mutation was less common in sites in western border regions (29 of 155 isolates) compared to samples from the east and north (40 of 51 isolates; p < 0.0001). The overall proportion of parasites with multiple pfmdr1 copies (greater than 1.5) was 5.5 %. Seven samples showed both k13 mutation and multiple copies of pfmdr1. Only one of 36 patients followed up after artemether-lumefantrine treatment still had parasites at day 3; molecular analysis indicated wild-type k13 and single copy pfmdr1. CONCLUSION: The proportion of P. falciparum isolates with mutations in the propeller region of k13 indicates that artemisinin resistance extends across much of Myanmar. There is a low prevalence of parasites with multiple pfmdr1 copies across the country. The efficacy of artemisinin-based combination therapy containing mefloquine and lumefantrine is, therefore, expected to be high, although regular monitoring of efficacy will be important.

Grigg MJ, Barber BE, Marfurt J, Imwong M, William T, Bird E, Piera KA, Aziz A, Boonyuen U, Drakeley CJ et al. 2016. Dihydrofolate-Reductase Mutations in Plasmodium knowlesi Appear Unrelated to Selective Drug Pressure from Putative Human-To-Human Transmission in Sabah, Malaysia. PLoS One, 11 (3), pp. e0149519. | Citations: 2 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Malaria caused by zoonotic Plasmodium knowlesi is an emerging threat in Eastern Malaysia. Despite demonstrated vector competency, it is unknown whether human-to-human (H-H) transmission is occurring naturally. We sought evidence of drug selection pressure from the antimalarial sulfadoxine-pyrimethamine (SP) as a potential marker of H-H transmission. METHODS: The P. knowlesi dihdyrofolate-reductase (pkdhfr) gene was sequenced from 449 P. knowlesi malaria cases from Sabah (Malaysian Borneo) and genotypes evaluated for association with clinical and epidemiological factors. Homology modelling using the pvdhfr template was used to assess the effect of pkdhfr mutations on the pyrimethamine binding pocket. RESULTS: Fourteen non-synonymous mutations were detected, with the most common being at codon T91P (10.2%) and R34L (10.0%), resulting in 21 different genotypes, including the wild-type, 14 single mutants, and six double mutants. One third of the P. knowlesi infections were with pkdhfr mutants; 145 (32%) patients had single mutants and 14 (3%) had double-mutants. In contrast, among the 47 P. falciparum isolates sequenced, three pfdhfr genotypes were found, with the double mutant 108N+59R being fixed and the triple mutants 108N+59R+51I and 108N+59R+164L occurring with frequencies of 4% and 8%, respectively. Two non-random spatio-temporal clusters were identified with pkdhfr genotypes. There was no association between pkdhfr mutations and hyperparasitaemia or malaria severity, both hypothesized to be indicators of H-H transmission. The orthologous loci associated with resistance in P. falciparum were not mutated in pkdhfr. Subsequent homology modelling of pkdhfr revealed gene loci 13, 53, 120, and 173 as being critical for pyrimethamine binding, however, there were no mutations at these sites among the 449 P. knowlesi isolates. CONCLUSION: Although moderate diversity was observed in pkdhfr in Sabah, there was no evidence this reflected selective antifolate drug pressure in humans.

Canavati SE, Lawford HLS, Fatunmbi BS, Lek D, Top-Samphor N, Leang R, Dondorp AM, Huy R, Kazadi WM. 2016. Establishing research priorities for malaria elimination in the context of the emergency response to artemisinin resistance framework-the Cambodian approach. Malar J, 15 (1), pp. 120. | Citations: 6 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Countries of the greater Mekong subregion have made a transition from malaria control to an aim for falciparum and vivax malaria elimination. The elimination of falciparum malaria will have to be achieved against a background of increasing artemisinin and multi-drug resistance. This ambitious goal requires an operational research (OR) agenda that addresses the dynamic challenges encountered on the path to elimination, which will need to be flexible and developed in close relation with the cambodian national programme for parasitology, entomology and malaria control (CNM). In Cambodia, a number of meetings with stakeholders were convened by the CNM and emergency response to artemisinin resistance (ERAR) hub, producing an initial list of priority OR topics. The process and outcome of these meetings are described, which could serve as a template for other countries in the region. METHODS: A landscaping exercise was conducted to gather all past, on-going and planned malaria focussed OR activities conducted by the cambodian research consortium in Cambodia and categorized according to research theme. The six themes included (1) malaria epidemiology, surveillance and response, (2) malaria case management, (3) malaria vector control, (4) malaria behavioural issues, (5) malaria clinical studies, and (6) other vector-borne diseases (dengue, neglected tropical diseases, soil-transmitted helminths). The different themes were discussed in small focus groups, which made an initial prioritization list which was then presented to a plenary group for further discussion. This produced a list of research questions ranked according to priority. RESULTS: OR priorities produced by the thematic groups were discussed in the plenary meeting and given a priority score by group voting. A list of 17 OR questions were developed, finalized and listed, which included questions on surveillance, active case detection and treatment efficacy. CONCLUSION: This paper describes ERAR's work on supporting Cambodia's transition to malaria elimination by identifying national operational research priorities. ERAR has initiated and currently plays a critical role in the development of country specific research agendas for malaria elimination. The first example of this has been the described exercise in Cambodia, which could serve a template for setting OR priorities in the wider region.

Wirjanata G, Handayuni I, Zaloumis SG, Chalfein F, Prayoga P, Kenangalem E, Poespoprodjo JR, Noviyanti R, Simpson JA, Price RN, Marfurt J. 2016. Analysis of ex vivo drug response data of Plasmodium clinical isolates: the pros and cons of different computer programs and online platforms. Malar J, 15 (1), pp. 137. | Show Abstract | Read more

BACKGROUND: In vitro drug susceptibility testing of malaria parasites remains an important component of surveillance for anti-malarial drug resistance. The half-maximal inhibition of growth (IC50) is the most commonly reported parameter expressing drug susceptibility, derived by a variety of statistical approaches, each with its own advantages and disadvantages. METHODS: In this study, licensed computer programs WinNonlin and GraphPad Prism 6.0, and the open access programs HN-NonLin, Antimalarial ICEstimator (ICE), and In Vitro Analysis and Reporting Tool (IVART) were tested for their ease of use and ability to estimate reliable IC50 values from raw drug response data from 31 Plasmodium falciparum and 29 P. vivax clinical isolates tested with five anti-malarial agents: chloroquine, amodiaquine, piperaquine, mefloquine, and artesunate. RESULTS: The IC50 and slope estimates were similar across all statistical packages for all drugs tested in both species. There was good correlation of results derived from alternative statistical programs and non-linear mixed-effects modelling (NONMEM) which models all isolate data simultaneously. The user-friendliness varied between packages. While HN-NonLin and IVART allow users to enter the data in 96-well format, IVART and GraphPad Prism 6.0 are capable to analyse multiple isolates and drugs in parallel. WinNonlin, GraphPad Prism 6.0, IVART, and ICE provide alerts for non-fitting data and incorrect data entry, facilitating data interpretation. Data analysis using WinNonlin or ICE took the longest computationally, whilst the offline ability of GraphPad Prism 6.0 to analyse multiple isolates and drugs simultaneously made it the fastest among the programs tested. CONCLUSION: IC50 estimates obtained from the programs tested were comparable. In view of processing time and ease of analysis, GraphPad Prism 6.0 or IVART are best suited for routine and large-scale drug susceptibility testing.

Hodgson SH, Angus BJ. 2016. Malaria: fluid therapy in severe disease. BMJ Clin Evid, 2016 | Show Abstract

INTRODUCTION: Severe malaria mainly affects children aged under 5 years, non-immune travellers, migrants to malarial areas, and people living in areas with unstable or seasonal malaria. Cerebral malaria, causing encephalopathy and coma, is fatal in around 20% of children and adults, and may lead to neurological sequelae in survivors. Severe malarial anaemia may have a mortality rate of over 13%. The role of fluid resuscitation in severe malaria is complex and controversial. Volume expansion could help to improve impaired organ perfusion and correct metabolic acidosis. However, rapid volume expansion could aggravate intracranial hypertension associated with cerebral malaria, leading to an increased risk of cerebral herniation. METHODS AND OUTCOMES: We conducted a systematic overview, aiming to answer the following clinical question: What is the optimal method of fluid resuscitation in patients with severe malaria? We searched: Medline, Embase, The Cochrane Library, and other important databases up to December 2014 (Clinical Evidence overviews are updated periodically; please check our website for the most up-to-date version of this overview). RESULTS: At this update, searching of electronic databases retrieved 187 studies. After deduplication and removal of conference abstracts, 93 records were screened for inclusion in the overview. Appraisal of titles and abstracts led to the exclusion of 82 studies and the further review of 11 full publications. Of the 11 full articles evaluated, two systematic reviews and three RCTs were added at this update. We performed a GRADE evaluation for seven PICO combinations. CONCLUSIONS: In this systematic overview, we categorised the efficacy for three interventions based on information about the effectiveness and safety of human albumin, intravenous fluids, and whole blood or plasma.

MalariaGEN Plasmodium falciparum Community Project. 2016. Genomic epidemiology of artemisinin resistant malaria. Elife, 5 (MARCH2016), | Citations: 21 (Scopus) | Show Abstract | Read more

The current epidemic of artemisinin resistant Plasmodium falciparum in Southeast Asia is the result of a soft selective sweep involving at least 20 independent kelch13 mutations. In a large global survey, we find that kelch13 mutations which cause resistance in Southeast Asia are present at low frequency in Africa. We show that African kelch13 mutations have originated locally, and that kelch13 shows a normal variation pattern relative to other genes in Africa, whereas in Southeast Asia there is a great excess of non-synonymous mutations, many of which cause radical amino-acid changes. Thus, kelch13 is not currently undergoing strong selection in Africa, despite a deep reservoir of variations that could potentially allow resistance to emerge rapidly. The practical implications are that public health surveillance for artemisinin resistance should not rely on kelch13 data alone, and interventions to prevent resistance must account for local evolutionary conditions, shown by genomic epidemiology to differ greatly between geographical regions.

Lubell Y, Althaus T, Blacksell SD, Paris DH, Mayxay M, Pan-Ngum W, White LJ, Day NPJ, Newton PN. 2016. Modelling the Impact and Cost-Effectiveness of Biomarker Tests as Compared with Pathogen-Specific Diagnostics in the Management of Undifferentiated Fever in Remote Tropical Settings. PLoS One, 11 (3), pp. e0152420. | Citations: 7 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Malaria accounts for a small fraction of febrile cases in increasingly large areas of the malaria endemic world. Point-of-care tests to improve the management of non-malarial fevers appropriate for primary care are few, consisting of either diagnostic tests for specific pathogens or testing for biomarkers of host response that indicate whether antibiotics might be required. The impact and cost-effectiveness of these approaches are relatively unexplored and methods to do so are not well-developed. METHODS: We model the ability of dengue and scrub typhus rapid tests to inform antibiotic treatment, as compared with testing for elevated C-Reactive Protein (CRP), a biomarker of host-inflammation. Using data on causes of fever in rural Laos, we estimate the proportion of outpatients that would be correctly classified as r