Tropical Medicine publications 2010

Mabotuwana T, Warren J, Elley CR, Kennelly J, Paton C, Wai KC, Wells S. 2010. Quality indicators to measure blood pressure management over a time interval. Inform Prim Care, 18 (3), pp. 149-156. | Citations: 1 (Scopus) | Show Abstract

BACKGROUND: Quality indicators are an important part of the primary care landscape, but focus strongly on point-in-time measurements, such as a patient's last blood pressure (BP) measurement. There is a larger space of possible measurements, including ones that more explicitly consider management over an interval of time. OBJECTIVE: To determine the predictive abilities of five different quality indicators related to poor BP control. METHODS: Data from two New Zealand general practices was analysed on five BP control indicators for patients with diagnosed hypertension: 1) last BP high (>150/90 mmHg); 2) last BP high or no BP measurement; 3) two or more consistently high BP measurements for ≥ 90 days; 4) a high BP then lapse of >120 days in BP measurement; and 5) antihypertensive medication possession ratio (MPR) of <80%. Probability that a patient would be identified by each indicator for the nine-month evaluation period ending 31 March 2009 was computed for each indicator one quarter, two quarters and three quarters prior to this date. Associations among the five indicators for the evaluation period were also calculated. RESULTS: Positive predictive value (PPV) of indicators for the same indicator nine months later ranged from 27% (last BP high) to 64% (MPR). PPVs among the five measures with respect to the same time period ranged from 9% to 77% (median 33%). CONCLUSIONS: Modest PPVs between indicators suggest the importance of considering multiple indicators to incentivise best management across diverse aspects of BP control.

Burgoine KL, Bancone G, Nosten F. 2010. The reality of using primaquine. Malar J, 9 (1), pp. 376. | Citations: 27 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Primaquine is currently the only medication used for radical cure of Plasmodium vivax infection. Unfortunately, its use is not without risk. Patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency have an increased susceptibility to haemolysis when given primaquine. This potentially fatal clinical syndrome can be avoided if patients are tested for G6PD deficiency and adequately informed before being treated. CASE PRESENTATION: A 35-year old male presented to our clinic on the Thai-Burmese border with a history and clinical examination consistent with intravascular haemolysis. The patient had been prescribed primaquine and chloroquine four days earlier for a P. vivax infection. The medication instructions had not been given in a language understood by the patient and he had not been tested for G6PD deficiency. The patient was not only G6PD deficient but misunderstood the instructions and took all his primaquine tablets together. With appropriate treatment the patient recovered and was discharged home a week later. CONCLUSIONS: Whilst primaquine remains the drug of choice to eradicate hypnozoites and control P. vivax transmission, the risks associated with its use must be minimized during its deployment. In areas where P. vivax exists, patients should be tested for G6PD deficiency and adequately informed before administration of primaquine.

Lourens C, Watkins WM, Barnes KI, Sibley CH, Guerin PJ, White NJ, Lindegardh N. 2010. Implementation of a reference standard and proficiency testing programme by the World Wide Antimalarial Resistance Network (WWARN). Malar J, 9 (1), pp. 375. | Citations: 13 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: The Worldwide Antimalarial Resistance Network (WWARN) is a global collaboration to support the objective that anyone affected by malaria receives effective and safe drug treatment. The Pharmacology module aims to inform optimal anti-malarial drug selection. There is an urgent need to define the drug exposure - effect relationship for most anti-malarial drugs. Few anti-malarials have had their therapeutic blood concentration levels defined. One of the main challenges in assessing safety and efficacy data in relation to drug concentrations is the comparability of data generated from different laboratories. To explain differences in anti-malarial pharmacokinetics in studies with different measurement laboratories it is necessary to confirm the accuracy of the assay methods. This requires the establishment of an external quality assurance process to assure results that can be compared. This paper describes this process. METHODS: The pharmacology module of WWARN has established a quality assurance/quality control (QA/QC) programme consisting of two separate components:1. A proficiency testing programme where blank human plasma spiked with certified reference material (CRM) in different concentrations is sent out to participating bioanalytical laboratories.2. A certified reference standard programme where accurately weighed amounts of certified anti-malarial reference standards, metabolites, and internal standards are sent to participating bioanalytical and in vitro laboratories. CONCLUSION: The proficiency testing programme is designed as a cooperative effort to help participating laboratories assess their ability to carry out drug analysis, resolve any potential problem areas and to improve their results - and, in so doing, to improve the quality of anti-malarial pharmacokinetic data published and shared with WWARN.By utilizing the same source of standards for all laboratories, it is possible to minimize bias arising from poor quality reference standards. By providing anti-malarial drug standards from a central point, it is possible to lower the cost of these standards.

Chapman SJ, Khor CC, Vannberg FO, Rautanen A, Walley A, Segal S, Moore CE, Davies RJO, Day NP, Peshu N et al. 2010. Common NFKBIL2 polymorphisms and susceptibility to pneumococcal disease: a genetic association study. Crit Care, 14 (6), pp. R227. | Citations: 12 (Scopus) | Show Abstract | Read more

INTRODUCTION: Streptococcus pneumoniae remains a major global health problem and a leading cause of death in children worldwide. The factors that influence development of pneumococcal sepsis remain poorly understood, although increasing evidence points towards a role for genetic variation in the host's immune response. Recent insights from the study of animal models, rare human primary immunodeficiency states, and population-based genetic epidemiology have focused attention on the role of the proinflammatory transcription factor NF-κB in pneumococcal disease pathogenesis. The possible role of genetic variation in the atypical NF-κB inhibitor IκB-R, encoded by NFKBIL2, in susceptibility to invasive pneumococcal disease has not, to our knowledge, previously been reported upon. METHODS: An association study was performed examining the frequencies of nine common NFKBIL2 polymorphisms in two invasive pneumococcal disease case-control groups: European individuals from hospitals in Oxfordshire, UK (275 patients and 733 controls), and African individuals from Kilifi District Hospital, Kenya (687 patients with bacteraemia, of which 173 patients had pneumococcal disease, together with 550 controls). RESULTS: Five polymorphisms significantly associated with invasive pneumococcal disease susceptibility in the European study, of which two polymorphisms also associated with disease in African individuals. Heterozygosity at these loci was associated with protection from invasive pneumococcal disease (rs760477, Mantel-Haenszel 2 × 2 χ(2) = 11.797, P = 0.0006, odds ratio = 0.67, 95% confidence interval = 0.53 to 0.84; rs4925858, Mantel-Haenszel 2 × 2 χ(2) = 9.104, P = 0.003, odds ratio = 0.70, 95% confidence interval = 0.55 to 0.88). Linkage disequilibrium was more extensive in European individuals than in Kenyans. CONCLUSIONS: Common NFKBIL2 polymorphisms are associated with susceptibility to invasive pneumococcal disease in European and African populations. These findings further highlight the importance of control of NF-κB in host defence against pneumococcal disease.

White NJ. 2010. Artemisinin resistance--the clock is ticking. Lancet, 376 (9758), pp. 2051-2052. | Citations: 68 (Scopus) | Read more

Olotu A, Fegan G, Williams TN, Sasi P, Ogada E, Bauni E, Wambua J, Marsh K, Borrmann S, Bejon P. 2010. Defining clinical malaria: the specificity and incidence of endpoints from active and passive surveillance of children in rural Kenya. PLoS One, 5 (12), pp. e15569. | Citations: 23 (Scopus) | Show Abstract | Read more

BACKGROUND: Febrile malaria is the most common clinical manifestation of P. falciparum infection, and is often the primary endpoint in clinical trials and epidemiological studies. Subjective and objective fevers are both used to define the endpoint, but have not been carefully compared, and the relative incidence of clinical malaria by active and passive case detection is unknown. METHODS: We analyzed data from cohorts under active and passive surveillance, including 19,462 presentations with fever and 5,551 blood tests for asymptomatic parasitaemia. A logistic regression model was used to calculate Malaria Attributable Fractions (MAFs) for various case definitions. Incidences of febrile malaria by active and passive surveillance were compared in a subset of children matched for age and location. RESULTS: Active surveillance identified three times the incidence of clinical malaria as passive surveillance in a subset of children matched for age and location. Objective fever (temperature≥37.5°C) gave consistently higher MAFs than case definitions based on subjective fever. CONCLUSION: The endpoints from active and passive surveillance have high specificity, but the incidence of endpoints is lower on passive surveillance. Subjective fever had low specificity and should not be used in primary endpoint. Passive surveillance will reduce the power of clinical trials but may cost-effectively deliver acceptable sensitivity in studies of large populations.

Ntoburi S, Hutchings A, Sanderson C, Carpenter J, Weber M, English M, Paediatric Quality of Hospital Care Indicator Panel. 2010. Development of paediatric quality of inpatient care indicators for low-income countries - A Delphi study. BMC Pediatr, 10 (1), pp. 90. | Citations: 16 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Indicators of quality of care for children in hospitals in low-income countries have been proposed, but information on their perceived validity and acceptability is lacking. METHODS: Potential indicators representing structural and process aspects of care for six common conditions were selected from existing, largely qualitative WHO assessment tools and guidelines. We employed the Delphi technique, which combines expert opinion and existing scientific information, to assess their perceived validity and acceptability. Panels of experts, one representing an international panel and one a national (Kenyan) panel, were asked to rate the indicators over 3 rounds and 2 rounds respectively according to a variety of attributes. RESULTS: Based on a pre-specified consensus criteria most of the indicators presented to the experts were accepted: 112/137(82%) and 94/133(71%) for the international and local panels respectively. For the other indicators there was no consensus; none were rejected. Most indicators were rated highly on link to outcomes, reliability, relevance, actionability and priority but rated more poorly on feasibility of data collection under routine conditions. There was moderate to substantial agreement between the two panels of experts. CONCLUSIONS: This Delphi study provided evidence for the perceived usefulness of most of a set of measures of quality of hospital care for children proposed for use in low-income countries. However, both international and local experts expressed concerns that data for many process-based indicators may not currently be available. The feasibility of widespread quality assessment and responsiveness of indicators to intervention should be examined as part of continued efforts to improve approaches to informative hospital quality assessment.

Lubell Y. 2010. Cost-effective use of prereferral treatment for severe malaria. Lancet, 376 (9756), pp. 1880-1881. | Citations: 1 (Web of Science Lite) | Read more

Hoang LT, Lynn DJ, Henn M, Birren BW, Lennon NJ, Le PT, Duong KTH, Nguyen TTH, Mai LN, Farrar JJ et al. 2010. The early whole-blood transcriptional signature of dengue virus and features associated with progression to dengue shock syndrome in Vietnamese children and young adults. J Virol, 84 (24), pp. 12982-12994. | Citations: 61 (Scopus) | Show Abstract | Read more

Dengue is a pantropic public health problem. In children, dengue shock syndrome (DSS) is the most common life-threatening complication. The ability to predict which patients may develop DSS may improve triage and treatment. To this end, we conducted a nested case-control comparison of the early host transcriptional features in 24 DSS patients and 56 sex-, age-, and virus serotype-matched uncomplicated (UC) dengue patients. In the first instance, we defined the "early dengue" profile. The transcriptional signature in acute rather than convalescent samples (≤72 h post-illness onset) was defined by an overabundance of interferon-inducible transcripts (31% of the 551 overabundant transcripts) and canonical gene ontology terms that included the following: response to virus, immune response, innate immune response, and inflammatory response. Pathway and network analyses identified STAT1, STAT2, STAT3, IRF7, IRF9, IRF1, CEBPB, and SP1 as key transcriptional factors mediating the early response. Strikingly, the only difference in the transcriptional signatures of early DSS and UC dengue cases was the greater abundance of several neutrophil-associated transcripts in patients who progressed to DSS, a finding supported by higher plasma concentrations of several canonical proteins associated with neutrophil degranulation (bactericidal/permeability-increasing protein [BPI], elastase 2 [ELA2], and defensin 1 alpha [DEF1A]). Elevated levels of neutrophil-associated transcripts were independent of the neutrophil count and also of the genotype of the infecting virus, as genome-length sequences of dengue virus serotype 1 (DENV-1) (n = 15) and DENV-2 (n = 3) sampled from DSS patients were phylogenetically indistinguishable from those sampled from uncomplicated dengue patients (32 DENV-1 and 9 DENV-2 sequences). Collectively, these data suggest a hitherto unrecognized association between neutrophil activation, pathogenesis, and the development of DSS and point to future strategies for guiding prognosis.

McGready R, Wuthiekanun V, Ashley EA, Tan SO, Pimanpanarak M, Viladpai-Nguen SJ, Jesadapanpong W, Blacksell SD, Proux S, Day NP et al. 2010. Diagnostic and treatment difficulties of pyelonephritis in pregnancy in resource-limited settings. Am J Trop Med Hyg, 83 (6), pp. 1322-1329. | Citations: 8 (Scopus) | Show Abstract | Read more

Limited microbiology services impede adequate diagnosis and treatment of common infections such as pyelonephritis in resource-limited settings. Febrile pregnant women attending antenatal clinics at Shoklo Malaria Research Unit were offered urine dipstick, sediment microscopy, urine culture, and a 5-mL blood culture. The incidence of pyelonephritis was 11/1,000 deliveries (N = 53 in 4,819 pregnancies) between January 7, 2004 and May 17, 2006. Pyelonephritis accounted for 20.2% (41/203) of fever cases in pregnancy. Escherichia coli was the most commonly isolated pathogen: 87.5% (28/32) of organisms cultured. Susceptibility of E. coli to ampicillin (14%), cotrimoxazole (21%), and amoxicillin-clavulanic acid (48%) was very low. E. coli was susceptible to ceftriaxone and ciprofloxacin. The rate of extended spectrum β-lactamase (4.2%; 95% confidence interval = 0.7-19.5) was low. The rate and causes of pyelonephritis in pregnant refugee and migrant women were comparable with those described in developed countries. Diagnostic innovation in microbiology that permits affordable access is a high priority for resource-poor settings.

Mayxay M, Keomany S, Khanthavong M, Souvannasing P, Stepniewska K, Khomthilath T, Keola S, Pongvongsa T, Phompida S, Ubben D et al. 2010. A phase III, randomized, non-inferiority trial to assess the efficacy and safety of dihydroartemisinin-piperaquine in comparison with artesunate-mefloquine in patients with uncomplicated Plasmodium falciparum malaria in southern Laos. Am J Trop Med Hyg, 83 (6), pp. 1221-1229. | Citations: 23 (Scopus) | Show Abstract | Read more

We conducted an open, randomized clinical trial of oral dihydroartemisinin-piperaquine (DP) versus artesunate-mefloquine (AM) in 300 patients in Laos with uncomplicated Plasmodium falciparum malaria as part of a multicentre study in Asia. Survival analysis and adjustment for re-infection showed that the 63-day cure rates (95% confidence interval [CI]) were 100% for AM and 99.5% (96.4-99.8%) for DP. The 63-day cure rates per protocol were 99% (97 of 98) for AM and 99.5% (196 of 197) for DP (P = 0.55). The difference (AM minus DP) in cure rates (95% CI) was -0.5% (-5.1 to 2.0%), which is within the 5% non-inferiority margin. The median fever and parasite clearance times were also similar for AM and DP. The proportion of patients with at least one recorded potential adverse event was significantly higher in the AM group (38 of 87, 44%) than in the DP group (57 of 182, 31%) (relative risk = 0.6, 95% CI = 0.4-0.9; P = 0.04). Dihydroartemisinin-piperaquine is not inferior to AM in the treatment of uncomplicated P. falciparum malaria in Laos and is associated with fewer adverse effects. The results of this study were similar to those of the larger multicentre study.

Guzman MG, Halstead SB, Artsob H, Buchy P, Farrar J, Gubler DJ, Hunsperger E, Kroeger A, Margolis HS, Martínez E et al. 2010. Dengue: a continuing global threat. Nat Rev Microbiol, 8 (12 Suppl), pp. S7-16. | Citations: 834 (Scopus) | Show Abstract | Read more

Dengue fever and dengue haemorrhagic fever are important arthropod-borne viral diseases. Each year, there are ∼50 million dengue infections and ∼500,000 individuals are hospitalized with dengue haemorrhagic fever, mainly in Southeast Asia, the Pacific and the Americas. Illness is produced by any of the four dengue virus serotypes. A global strategy aimed at increasing the capacity for surveillance and outbreak response, changing behaviours and reducing the disease burden using integrated vector management in conjunction with early and accurate diagnosis has been advocated. Antiviral drugs and vaccines that are currently under development could also make an important contribution to dengue control in the future.

Tran TH, Jarrell A, Zentner GE, Welsh A, Brownell I, Scacheri PC, Atit R. 2010. Role of canonical Wnt signaling/ß-catenin via Dermo1 in cranial dermal cell development. Development, 137 (23), pp. 3973-3984. | Citations: 29 (Scopus) | Show Abstract | Read more

Cranial dermis develops from cephalic mesoderm and neural crest cells, but what signal(s) specifies the dermal lineage is unclear. Using genetic tools to fate map and manipulate a cranial mesenchymal progenitor population in the supraorbital region, we show that the dermal progenitor cells beneath the surface ectoderm process canonical Wnt signaling at the time of specification. We show that Wnt signaling/β-catenin is absolutely required and sufficient for Dermo1 expression and dermal cell identity in the cranium. The absence of the Wnt signaling cue leads to formation of cartilage in craniofacial and ventral trunk regions at the expense of dermal and bone lineages. Dermo1 can be a direct transcription target and may mediate the functional role of Wnt signaling in dermal precursors. This study reveals a lineage-specific role of canonical Wnt signaling/β-catenin in promoting dermal cell fate in distinct precursor populations.

Cha K-H, Tran T-H, Kim M-S, Kim J-S, Park HJ, Park J, Cho W, Hwang S-J. 2010. pH-independent sustained release matrix tablet containing doxazosin mesylate: effect of citric acid. Arch Pharm Res, 33 (12), pp. 2003-2009. | Citations: 1 (Scopus) | Show Abstract | Read more

The aim of this study was to develop a pH-independent sustained release matrix tablets of doxazosin mesylate. The matrix tablets were prepared by direct compression technique using polyethylene oxide, sodium alginate and citric acid as a pH modifier. Formulations were evaluated for an in vitro drug release study, erosion study, and the microenvironmental pH was studied using the pH indicator methyl red. For formulations without citric acid, the extent and rate of drug release in simulated gastric fluid were much higher than those in simulated intestinal fluid. By adding the citric acid, the drug release rate in simulated intestinal fluid was increased, and microenvironmental pH values within the tablets were maintained at low pH during drug release. Furthermore, drug release from the matrix tablet containing 20% w/w citric acid was comparable to that from a commercial product, Cardura® XL, and a pH-independent release could be achieved. Therefore, the incorporation of citric acid as a pH modifier to Polyethylene oxide-sodium alginate matrix tablets effectively produced pH-independent doxazosin mesylate release profiles.

Wang S-M, Ma J-C, Hao Z-Y, Zhang Z-Y, Mason C, Sethabutr O, von Seidlein L, Wang X-Y, Xu Z-Y. 2010. Surveillance of shigellosis by real-time PCR suggests underestimation of shigellosis prevalence by culture-based methods in a population of rural China. J Infect, 61 (6), pp. 471-475. | Citations: 15 (Scopus) | Show Abstract | Read more

INTRODUCTION: Shigellosis is a leading public health issue in China, especially in Children under 5 years of age. The disease burden of shigellosis is usually underestimated by conventional culture. In this study, real-time PCR was applied to detect Shigella infection in parallel with routine culture, to investigate the true burden of disease caused by Shigella spp. METHODS: Rectal swab specimens of 39 Shigella culture positive and 298 Shigella culture negative patients from a population-based surveillance study were selected randomly. Real-time PCR targeting the invasion plasmid antigen H gene sequence (ipaH) was used to detect DNA sequences characteristic for Shigella spp. RESULTS: ipaH were detected in 174 of 298 (58%) randomly selected Shigella culture negative specimens and in 38 of 39 (97%) Shigella culture positive specimens (p < 0.001). Among 10 variables, culture results was the strongest predictive factor (OR = 15.5; 95% CI: 2.0-119.0), followed by a clinical presentation of diarrhea with fever (OR = 2.8; 95% CI: 1.2-6.2), epidemic season (OR = 2.4; 95% CI: 1.4-4.3), and female gender (OR = 1.8; 95% CI: 1.1-3.0). CONCLUSION: The high detection rate of ipaH in culture negative specimens through use of real-time PCR suggests that earlier estimates of shigellosis burden measured by conventional culture may have underestimated the true disease burden.

Subedi BH, Pokharel J, Goodman TL, Amatya S, Freer L, Banskota N, Johnson E, Basnyat B. 2010. Complications of steroid use on Mt. Everest. Wilderness Environ Med, 21 (4), pp. 345-348. | Citations: 20 (Web of Science Lite) | Show Abstract | Read more

Steroids are used for the prevention and treatment of high-altitude illnesses. However, these agents can cause significant side effects. We report a case of altered mental status, gastrointestinal bleeding, skin rash, and avascular necrosis in a climber taking prophylactic dexamethasone prior to an attempt to climb Mt Everest. High-altitude cerebral edema (HACE), steroid toxicity, and acute adrenal crisis can have similar clinical presentations. Differentiating between these life-threatening conditions at high altitude is essential for successful treatment.

Atalag K, Kingsford D, Paton C, Warren J. 2010. Putting health record interoperability standards to work Electronic Journal of Health Informatics, 5 (1), | Citations: 18 (Scopus) | Show Abstract

This paper provides a snapshot of the current interoperability standards landscape and investigates how different standards are adopted in different jurisdictions. The aim is to provide useful insights for decision makers by looking from a wider angle to include political, social and business drivers rather than taking a purely technical approach. Semantic interoperability, which is a major bottleneck to achieving eHealth systemic interoperability, is dependent on terminology, content and messaging standards. In particular, the architectural aspects of content and messaging standards seem to be critical and currently the subject of many heated debates. A considerable amount of effort into international harmonisation is underway and evidence shows that it may be possible to use different standards and yet still be able to accomplish semantic interoperability. It is recommended that a careful analysis be performed to seek evidence, rather than relying on hearsay, for determining how each standard fulfils certain requirements depending on the context. An environmental scan and literature survey highlights the fact that making a good choice of standards depends on what outcomes are desired, and usually involves selection of a number of different standards to be applied together. It is to be noted that, non-technical aspects of standards, such as acceptance, feasibility of implementation or availability of expertise, are as important, and determine what is achievable. The paper concludes by presenting a number of options which include combinations of standards and also provides insights for the evaluation and selection process. © of articles is retained by authors.

de Vries HJC, Smelov V, Ouburg S, Pleijster J, Geskus RB, Speksnijder AGCL, Fennema JSA, Morré SA. 2010. Anal lymphogranuloma venereum infection screening with IgA anti-Chlamydia trachomatis-specific major outer membrane protein serology. Sex Transm Dis, 37 (12), pp. 789-795. | Citations: 21 (Scopus) | Show Abstract | Read more

BACKGROUND: Anal lymphogranuloma venereum (LGV) infections, caused by Chlamydia trachomatis biovar L (Ct+/LGV+), are endemic among men who have sex with men (MSM). Anal non-LGV biovar Ct infections (Ct+/LGV-) can be eradicated with 1 week doxycycline, whereas Ct+/LGV+ infections require 3-week doxycycline. To differentiate Ct+/LGV+ from Ct+/LGV- infections, biovar-specific Nucleic Acid Amplification Test (NAAT) are standard, but also expensive and laborious. A chlamydia-specific serological assay could serve as an alternative test. METHODS: MSM were screened for anal Ct+/LGV+ and Ct+/LGV- infections with a commercial nonspecific NAAT and an in house biovar L-specific NAAT. Serum samples were evaluated with chlamydia-specific anti-Major Outer Membrane Protein (MOMP) and antilipopolysaccharide assays of IgA and IgG classes. Asymptomatic patients were identified as: (1) no anal complaints or (2) no microscopic inflammation (i.e., <10 leucocytes per high power field in anal smears). The best differentiating assay was subsequently evaluated in 100 Ct+/LGV+ and 100 Ct+/LGV- MSM using different cut-off points. RESULTS: The anti-MOMP IgA assay was the most accurate to differentiate Ct+/LGV+ (n = 42) from Ct+/LGV- (n = 19) with 85.7% sensitivity (95% confidence interval [CI], 72.2-93.3) and 84.2% specificity (95% CI, 62.4-94.5), even among asymptomatic patients. In a population comprising 98 Ct+/LGV+ and 105 Ct+/LGV- patients, the anti-MOMP IgA assay scored most accurate when the cut-off point was set to 2.0 with 75.5% (95% CI, 65.8-83.6) sensitivity and 74.3% (95% CI, 64.8-82.3) specificity. CONCLUSIONS: The IgA anti-MOMP assay can identify a considerable proportion of the (asymptomatic) anal LGV infections correctly. Yet, biovar L-specific NAAT are still the preferred diagnostic tests in clinical settings.

Robinson MT, Morgan ER, Woods D, Shaw SE. 2010. The development of a qPCR assay to detect tick (Ixodida) DNA and its implementation for the study of tick-borne pathogen transmission. Exp Parasitol, 126 (4), pp. 506-509. | Show Abstract | Read more

Polymerase chain reaction (PCR) analysis is regularly used to detect pathogens within arthropod vectors, but has also been applied to investigate vector DNA. This study details a novel highly sensitive quantitative PCR (qPCR) which detects and quantifies DNA from Ixodes ricinus, the European vector of Anaplasma phagocytophilum. By pairing this with a qPCR to detect A. phagocytophilum, valid comparisons of pathogen load can be made between different sized tick-tissue samples. These qPCRs were validated in I. ricinus that were fed A. phagocytophilum-infected blood using an artificial membrane feeder. Pathogens were detected in the tick haemolymph within 36h, indicating that successful infection had taken place. This study illustrates the application of vector-targeted qPCRs to confirm and validate pathogen load in samples as part of investigations of vector-pathogen interactions.

Lusingu J, Olotu A, Leach A, Lievens M, Vekemans J, Olivier A, Benns S, Olomi R, Msham S, Lang T et al. 2010. Safety of the malaria vaccine candidate, RTS,S/AS01E in 5 to 17 month old Kenyan and Tanzanian Children. PLoS One, 5 (11), pp. e14090. | Citations: 16 (Scopus) | Show Abstract | Read more

The malaria vaccine candidate, RTS,S/AS01(E), showed promising protective efficacy in a trial of Kenyan and Tanzanian children aged 5 to 17 months. Here we report on the vaccine's safety and tolerability. The experimental design was a Phase 2b, two-centre, double-blind (observer- and participant-blind), randomised (1∶1 ratio) controlled trial. Three doses of study or control (rabies) vaccines were administered intramuscularly at 1 month intervals. Solicited adverse events (AEs) were collected for 7 days after each vaccination. There was surveillance and reporting for unsolicited adverse events for 30 days after each vaccination. Serious adverse events (SAEs) were recorded throughout the study period which lasted for 14 months after dose 1 in Korogwe, Tanzania and an average of 18 months post-dose 1 in Kilifi, Kenya. Blood samples for safety monitoring of haematological, renal and hepatic functions were taken at baseline, 3, 10 and 14 months after dose 1. A total of 894 children received RTS,S/AS01(E) or rabies vaccine between March and August 2007. Overall, children vaccinated with RTS,S/AS01(E) had fewer SAEs (51/447) than children in the control group (88/447). One SAE episode in a RTS,S/AS01(E) recipient and nine episodes among eight rabies vaccine recipients met the criteria for severe malaria. Unsolicited AEs were reported in 78% of subjects in the RTS,S/AS01(E) group and 74% of subjects in the rabies vaccine group. In both vaccine groups, gastroenteritis and pneumonia were the most frequently reported unsolicited AE. Fever was the most frequently observed solicited AE and was recorded after 11% of RTS,S/AS01(E) doses compared to 31% of doses of rabies vaccine. The candidate vaccine RTS,S/AS01(E) showed an acceptable safety profile in children living in a malaria-endemic area in East Africa. More data on the safety of RTS,S/AS01(E) will become available from the Phase 3 programme.

Study of the Effectiveness of Additional Reductions in Cholesterol and Homocysteine (SEARCH) Collaborative Group, Armitage J, Bowman L, Wallendszus K, Bulbulia R, Rahimi K, Haynes R, Parish S, Peto R, Collins R. 2010. Intensive lowering of LDL cholesterol with 80 mg versus 20 mg simvastatin daily in 12,064 survivors of myocardial infarction: a double-blind randomised trial. Lancet, 376 (9753), pp. 1658-1669. | Citations: 291 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Lowering of LDL cholesterol reduces major vascular events, but whether more intensive therapy safely produces extra benefits is uncertain. We aimed to establish efficacy and safety of more intensive statin treatment in patients at high cardiovascular risk. METHODS: We undertook a double-blind randomised trial in 12,064 men and women aged 18-80 years with a history of myocardial infarction. Participants were either currently on or had clear indication for statin therapy, and had a total cholesterol concentration of at least 3·5 mmol/L if already on a statin or 4·5 mmol/L if not. Randomisation to either 80 mg or 20 mg simvastatin daily was done centrally using a minimisation algorithm. Participants were assessed at 2, 4, 8, and 12 months after randomisation and then every 6 months until final follow-up. The primary endpoint was major vascular events, defined as coronary death, myocardial infarction, stroke, or arterial revascularisation. Analysis was by intention to treat. This study is registered, number ISRCTN74348595. FINDINGS: 6031 participants were allocated 80 mg simvastatin daily, and 6033 allocated 20 mg simvastatin daily. During a mean follow-up of 6·7 (SD 1·5) years, allocation to 80 mg simvastatin produced an average 0·35 (SE 0·01) mmol/L greater reduction in LDL cholesterol compared with allocation to 20 mg. Major vascular events occurred in 1477 (24·5%) participants allocated 80 mg simvastatin versus 1553 (25·7%) of those allocated 20 mg, corresponding to a 6% proportional reduction (risk ratio 0·94, 95% CI 0·88-1·01; p=0·10). There were no apparent differences in numbers of haemorrhagic strokes (24 [0·4%] vs 25 [0·4%]) or deaths attributed to vascular (565 [9·4%] vs 572 [9·5%]) or non-vascular (399 [6·6%] vs 398 [6·6%]) causes. Compared with two (0·03%) cases of myopathy in patients taking 20 mg simvastatin daily, there were 53 (0·9%) cases in the 80 mg group. INTERPRETATION: The 6% (SE 3·5%) reduction in major vascular events with a further 0·35 mmol/L reduction in LDL cholesterol in our trial is consistent with previous trials. Myopathy was increased with 80 mg simvastatin daily, but intensive lowering of LDL cholesterol can be achieved safely with other regimens. FUNDING: Merck; The Clinical Trial Service Unit also receives funding from the UK Medical Research Council and the British Heart Foundation.

Marsh K. 2010. Research priorities for malaria elimination. Lancet, 376 (9753), pp. 1626-1627. | Citations: 18 (Web of Science Lite) | Read more

Dondorp AM, Fanello CI, Hendriksen ICE, Gomes E, Seni A, Chhaganlal KD, Bojang K, Olaosebikan R, Anunobi N, Maitland K et al. 2010. Artesunate versus quinine in the treatment of severe falciparum malaria in African children (AQUAMAT): an open-label, randomised trial. Lancet, 376 (9753), pp. 1647-1657. | Citations: 370 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Severe malaria is a major cause of childhood death and often the main reason for paediatric hospital admission in sub-Saharan Africa. Quinine is still the established treatment of choice, although evidence from Asia suggests that artesunate is associated with a lower mortality. We compared parenteral treatment with either artesunate or quinine in African children with severe malaria. METHODS: This open-label, randomised trial was undertaken in 11 centres in nine African countries. Children (<15 years) with severe falciparum malaria were randomly assigned to parenteral artesunate or parenteral quinine. Randomisation was in blocks of 20, with study numbers corresponding to treatment allocations kept inside opaque sealed paper envelopes. The trial was open label at each site, and none of the investigators or trialists, apart from for the trial statistician, had access to the summaries of treatment allocations. The primary outcome measure was in-hospital mortality, analysed by intention to treat. This trial is registered, number ISRCTN50258054. FINDINGS: 5425 children were enrolled; 2712 were assigned to artesunate and 2713 to quinine. All patients were analysed for the primary outcome. 230 (8·5%) patients assigned to artesunate treatment died compared with 297 (10·9%) assigned to quinine treatment (odds ratio [OR] stratified for study site 0·75, 95% CI 0·63-0·90; relative reduction 22·5%, 95% CI 8·1-36·9; p=0·0022). Incidence of neurological sequelae did not differ significantly between groups, but the development of coma (65/1832 [3·5%] with artesunate vs 91/1768 [5·1%] with quinine; OR 0·69 95% CI 0·49-0·95; p=0·0231), convulsions (224/2712 [8·3%] vs 273/2713 [10·1%]; OR 0·80, 0·66-0·97; p=0·0199), and deterioration of the coma score (166/2712 [6·1%] vs 208/2713 [7·7%]; OR 0·78, 0·64-0·97; p=0·0245) were all significantly less frequent in artesunate recipients than in quinine recipients. Post-treatment hypoglycaemia was also less frequent in patients assigned to artesunate than in those assigned to quinine (48/2712 [1·8%] vs 75/2713 [2·8%]; OR 0·63, 0·43-0·91; p=0·0134). Artesunate was well tolerated, with no serious drug-related adverse effects. INTERPRETATION: Artesunate substantially reduces mortality in African children with severe malaria. These data, together with a meta-analysis of all trials comparing artesunate and quinine, strongly suggest that parenteral artesunate should replace quinine as the treatment of choice for severe falciparum malaria worldwide. FUNDING: The Wellcome Trust.

Tatem AJ, Smith DL, Gething PW, Kabaria CW, Snow RW, Hay SI. 2010. Ranking of elimination feasibility between malaria-endemic countries. Lancet, 376 (9752), pp. 1579-1591. | Citations: 93 (Scopus) | Show Abstract | Read more

Experience gained from the Global Malaria Eradication Program (1955-72) identified a set of shared technical and operational factors that enabled some countries to successfully eliminate malaria. Spatial data for these factors were assembled for all malaria-endemic countries and combined to provide an objective, relative ranking of countries by technical, operational, and combined elimination feasibility. The analysis was done separately for Plasmodium falciparum and Plasmodium vivax, and the limitations of the approach were discussed. The relative rankings suggested that malaria elimination would be most feasible in countries in the Americas and Asia, and least feasible in countries in central and west Africa. The results differed when feasibility was measured by technical or operational factors, highlighting the different types of challenge faced by each country. The results are not intended to be prescriptive, predictive, or to provide absolute assessments of feasibility, but they do show that spatial information is available to facilitate evidence-based assessments of the relative feasibility of malaria elimination by country that can be rapidly updated.

Moonen B, Cohen JM, Snow RW, Slutsker L, Drakeley C, Smith DL, Abeyasinghe RR, Rodriguez MH, Maharaj R, Tanner M, Targett G. 2010. Operational strategies to achieve and maintain malaria elimination. Lancet, 376 (9752), pp. 1592-1603. | Citations: 192 (Web of Science Lite) | Show Abstract | Read more

Present elimination strategies are based on recommendations derived during the Global Malaria Eradication Program of the 1960s. However, many countries considering elimination nowadays have high intrinsic transmission potential and, without the support of a regional campaign, have to deal with the constant threat of imported cases of the disease, emphasising the need to revisit the strategies on which contemporary elimination programmes are based. To eliminate malaria, programmes need to concentrate on identification and elimination of foci of infections through both passive and active methods of case detection. This approach needs appropriate treatment of both clinical cases and asymptomatic infections, combined with targeted vector control. Draining of infectious pools entirely will not be sufficient since they could be replenished by imported malaria. Elimination will thus additionally need identification and treatment of incoming infections before they lead to transmission, or, more realistically, embarking on regional initiatives to dry up importation at its source.

Le T, Huu Chi N, Kim Cuc NT, Manh Sieu TP, Shikuma CM, Farrar J, Day JN. 2010. AIDS-associated Penicillium marneffei infection of the central nervous system. Clin Infect Dis, 51 (12), pp. 1458-1462. | Citations: 15 (Scopus) | Show Abstract | Read more

Penicillium marneffei is an important human immunodeficiency virus-associated opportunistic infection endemic in Southeast Asia. Central nervous system infection has not been described. We report the first case series of 21 human immunodeficiency virus-infected patients who presented with a syndrome consistent with acute central nervous system infection and who had Penicillium marneffei isolated from cerebrospinal fluid.

Blessborn D, Romsing S, Bergqvist Y, Lindegardh N. 2010. Assay for screening for six antimalarial drugs and one metabolite using dried blood spot sampling, sequential extraction and ion-trap detection. Bioanalysis, 2 (11), pp. 1839-1847. | Citations: 18 (Scopus) | Show Abstract | Read more

BACKGROUND: More parasites are becoming resistant to antimalarial drugs, and in many areas a change in first-line drug treatment is necessary. The aim of the developed assay is to help determine drug use in these areas and also to be a complement to interviewing patients, which will increase reliability of surveys. RESULTS: This assay detects quinine, mefloquine, sulfadoxine, pyrimethamine, lumefantrine, chloroquine and its metabolite desethylchloroquine in a 100-µl dried blood spot. Most of the drugs also have long half-lives that make them detectable at least 7 days after administration. The drugs are extracted from the dried blood spot with sequential extraction (due to the big differences in physicochemical properties), solid-phase extraction is used as sample clean-up and separation is performed with gradient-LC with MS ion-trap detection. CONCLUSION: Detection limits (S/N > 5:1) at 50 ng/ml or better were achieved for all drugs except lumefantrine (200 ng/ml), and thus can be used to determine patient compliance. A major advantage of using the ion-trap MS it that it will be possible to go back into the data and look for other drugs as needed.

Pullan RL, Bukirwa H, Snow RW, Brooker S. 2010. Heritability of Plasmodium parasite density in a rural Ugandan community. Am J Trop Med Hyg, 83 (5), pp. 990-995. | Citations: 1 (Web of Science Lite) | Show Abstract | Read more

Many factors influence variation in Plasmodium infection levels, including parasite/host genetics, immunity, and exposure. Here, we examine the roles of host genetics and exposure in determining parasite density, and test whether effects differ with age. Data for 1,711 residents of an eastern Ugandan community were used in pedigree-based variance component analysis. Heritability of parasite density was 13% (P < 0.001) but was not significant after controlling for shared household. Allowing variance components to vary between children (< 16 years) and adults (≥ 16 years) revealed striking age differences; 26% of variation could be explained by additively acting genes in children (P < 0.001), but there was no genetic involvement in adults. Domestic environment did not explain variation in children and explained 5% in adults (P = 0.09). Genetic effects are an important determinant of parasite density in children in this population, consistent with previous quantitative genetic studies of Plasmodium parasitaemia, although differences in environmental exposure play a lesser role.

West TE, Myers ND, Limmathurotsakul D, Liggitt HD, Chantratita N, Peacock SJ, Skerrett SJ. 2010. Pathogenicity of high-dose enteral inoculation of Burkholderia pseudomallei to mice. Am J Trop Med Hyg, 83 (5), pp. 1066-1069. | Citations: 20 (Web of Science Lite) | Show Abstract | Read more

Melioidosis is a frequently lethal tropical infection caused by the environmental saprophyte Burkholderia pseudomallei. Although transcutaneous inoculation and inhalation are considered the primary routes of infection, suggestive clinical evidence implicates ingestion as a possible alternative route. We show that in BALB/c and C57BL/6 mice, direct gastric inoculation of high doses of B. pseudomallei causes systemic infection that may be lethal or cause chronic disseminated infection. Mice may shed bacteria in the stool for weeks after infection, and high titers of B. pseudomallei-specific IgG are detectable. This report of enteric murine melioidosis supports further consideration of this route of infection.

Hiscox A, Winter CH, Vongphrachanh P, Sisouk T, Somoulay V, Phompida S, Kaul S, Sananikhom P, Nguyen TY, Paul RE et al. 2010. Serological investigations of flavivirus prevalence in Khammouane Province, Lao People's Democratic Republic, 2007-2008. Am J Trop Med Hyg, 83 (5), pp. 1166-1169. | Citations: 17 (Web of Science Lite) | Show Abstract | Read more

A large-scale cross-sectional seroprevalence study of dengue (DEN) and Japanese encephalitis (JE) was conducted in Khammouane province, Lao PDR, as part of the initial baseline health impact assessment of the Nam Theun 2 hydroelectric dam construction project. Health surveys were performed between May 2007 and February 2008 with serum samples collected from healthy individuals involved in the resettlement program of 16 villages (total surveyed population 4,369). Hemagglutination inhibition assay using flavivirus antigens (DENV1, DENV3, and JEV) performed on 1,708 plasma specimens revealed 30.4% (519) cross-reactive positives, and 10% (172) and 1.3% (22) positives to JEV or DENV, respectively. Entomological surveys conducted during the rainy season of 2008 indicated the presence of competent flavivirus vectors (Culex vishnui group and Aedes albopictus), although Aedes aegypti was not found. Continued surveillance and investigation is warranted to assess the clinical disease burden of flaviviruses in this area that is undergoing rapid ecological and demographic change.

Duke T, Graham SM, Cherian MN, Ginsburg AS, English M, Howie S, Peel D, Enarson PM, Wilson IH, Were W, Union Oxygen Systems Working Group. 2010. Oxygen is an essential medicine: a call for international action. Int J Tuberc Lung Dis, 14 (11), pp. 1362-1368. | Show Abstract

Hypoxaemia is commonly associated with mortality in developing countries, yet feasible and cost-effective ways to address hypoxaemia receive little or no attention in current global health strategies. Oxygen treatment has been used in medicine for almost 100 years, but in developing countries most seriously ill newborns, children and adults do not have access to oxygen or the simple test that can detect hypoxaemia. Improving access to oxygen and pulse oximetry has demonstrated a reduction in mortality from childhood pneumonia by up to 35% in high-burden child pneumonia settings. The cost-effectiveness of an oxygen systems strategy compares favourably with other higher profile child survival interventions, such as new vaccines. In addition to its use in treating acute respiratory illness, oxygen treatment is required for the optimal management of many other conditions in adults and children, and is essential for safe surgery, anaesthesia and obstetric care. Oxygen concentrators provide the most consistent and least expensive source of oxygen in health facilities where power supplies are reliable. Oxygen concentrators are sustainable in developing country settings if a systematic approach involving nurses, doctors, technicians and administrators is adopted. Improving oxygen systems is an entry point for improving the quality of care. For these broad reasons, and for its vital importance in reducing deaths due to lung disease in 2010: Year of the Lung, oxygen deserves a higher priority on the global health agenda.

Krishnan N, Robertson BD, Thwaites G. 2010. The mechanisms and consequences of the extra-pulmonary dissemination of Mycobacterium tuberculosis. Tuberculosis (Edinb), 90 (6), pp. 361-366. | Citations: 54 (Scopus) | Show Abstract | Read more

The dissemination of Mycobacterium tuberculosis from the primary focus of infection is central to the pathogenesis of tuberculosis. Trafficking of bacteria to the regional lymph nodes is essential to the development of a protective T-cell mediated immune response, but bacteria trafficked within the bloodstream can lead to extra-pulmonary dissemination and some of the most devastating clinical consequences of tuberculosis. Yet how M. tuberculosis leaves the lungs is poorly understood. Here, we review the potential pathways and molecular mechanisms behind the dissemination of M. tuberculosis and consider the consequences to both host and bacteria. To disseminate M. tuberculosis must breach the alveolar epithelium and various bacterial factors have been implicated in this process. Heparin binding haemagglutinin adhesin (HBHA) enables M. tuberculosis to bind to sulphated glycoconjugates on epithelial cells; disruption of its synthesis severely impairs the ability of bacteria to disseminate from the lungs to the spleen. Two products of the M. tuberculosis RD1 gene locus, early secretory antigenic target 6 kDa (ESAT-6) and culture filtrate protein 10 kDa (CFP-10), have been linked to cell lysis and may enable bacteria to invade and spread within the alveolar epithelium. Recent studies in embryonic zebrafish indicate ESAT-6 may also stimulate the trafficking of infected macrophages within granulomas, thereby promoting the early dissemination of bacteria. These findings challenge conventional notions of the protective role of granulomas in mycobacterial infection and indicate M. tuberculosis has evolved specific mechanisms which utilise granulomas as foci of macrophage recruitment, infection, and subsequent bacterial dissemination. Further understanding of the pathways, mechanisms and consequences of M. tuberculosis dissemination could have a major impact in designing novel vaccines and therapeutic strategies.

Marais S, Thwaites G, Schoeman JF, Török ME, Misra UK, Prasad K, Donald PR, Wilkinson RJ, Marais BJ. 2010. Tuberculous meningitis: a uniform case definition for use in clinical research. Lancet Infect Dis, 10 (11), pp. 803-812. | Citations: 213 (Scopus) | Show Abstract | Read more

Tuberculous meningitis causes substantial mortality and morbidity in children and adults. More research is urgently needed to better understand the pathogenesis of disease and to improve its clinical management and outcome. A major stumbling block is the absence of standardised diagnostic criteria. The different case definitions used in various studies makes comparison of research findings difficult, prevents the best use of existing data, and limits the management of disease. To address this problem, a 3-day tuberculous meningitis workshop took place in Cape Town, South Africa, and was attended by 41 international participants experienced in the research or management of tuberculous meningitis. During the meeting, diagnostic criteria were assessed and discussed, after which a writing committee was appointed to finalise a consensus case definition for tuberculous meningitis for use in future clinical research. We present the consensus case definition together with the rationale behind the recommendations. This case definition is applicable irrespective of the patient's age, HIV infection status, or the resources available in the research setting. Consistent use of the proposed case definition will aid comparison of studies, improve scientific communication, and ultimately improve care.

van Rijckevorsel GGC, Sonder GJB, Geskus RB, Wetsteyn JCFM, Ligthelm RJ, Visser LG, Keuter M, van Genderen PJJ, van den Hoek A. 2010. Declining incidence of imported malaria in the Netherlands, 2000-2007. Malar J, 9 (1), pp. 300. | Citations: 23 (Scopus) | Show Abstract | Read more

BACKGROUND: To describe the epidemiology and trends of imported malaria in the Netherlands from 2000 through 2007. METHODS: Based on national surveillance data regarding all reported infections of imported malaria, diagnosed 2000 through 2007, incidence and trends of imported malaria in the Netherlands were estimated. Travellers statistics were used to estimate incidence, and data on malaria chemoprophylaxis prescriptions were used to estimate the number of unprotected travellers. RESULTS: Importation of malaria to the Netherlands is declining even as more travellers visit malaria-endemic countries. On average, 82% were acquired in sub-Saharan Africa, and 75% were caused by Plasmodium falciparum. The overall incidence in imported falciparum malaria fell from 21.5 to 6.6/10,000 of unprotected travellers. The percentage of unprotected travellers rose from 47% to 52% of all travellers. The incidence of imported falciparum infections is greatest from Middle and West Africa, and decreased from 121.3 to 36.5/10,000 travellers. The import of malaria from this region by immigrants visiting friends and relatives (VFR) decreased from 138 infections in 2000, to 69 infections in 2007. CONCLUSION: The annual number of imported malaria shows a continuing declining trend, even with an increasing number of travellers visiting malaria endemic countries. VFR import less malaria than previously, and contribute largely to the declining incidence seen. The decline is not readily explained by increased use of chemoprophylaxis and may reflect a reduced risk of infection due to decreasing local malaria transmission as observed in some malaria endemic areas. Nevertheless, the increasing number of unprotected travellers remains worrisome.

Baird JK. 2010. Eliminating malaria--all of them. Lancet, 376 (9756), pp. 1883-1885. | Citations: 35 (Web of Science Lite) | Read more

Snow RW, Okiro EA, Gething PW, Atun R, Hay SI. 2010. Equity and adequacy of international donor assistance for global malaria control: an analysis of populations at risk and external funding commitments. Lancet, 376 (9750), pp. 1409-1416. | Citations: 41 (Scopus) | Show Abstract | Read more

BACKGROUND: Financing for malaria control has increased as part of international commitments to achieve the Millennium Development Goals (MDGs). We aimed to identify the unmet financial needs that would be biologically and economically equitable and would increase the chances of reaching worldwide malaria-control ambitions. METHODS: Populations at risk of stable Plasmodium falciparum or Plasmodium vivax transmission were calculated for 2007 and 2009 for 93 malaria-endemic countries to measure biological need. National per-person gross domestic product (GDP) was used to define economic need. An analysis of external donor assistance for malaria control was done for the period 2002-09 to compute overall and annualised per-person at-risk-funding commitments. Annualised malaria donor assistance was compared with independent predictions of funding needed to reach international targets of 80% coverage of best practices in case-management and effective disease prevention. Countries were ranked in relation to biological, economic, and unmet needs to examine equity and adequacy of support by 2010. FINDINGS: International financing for malaria control has increased by 166% (from $0·73 billion to $1·94 billion) since 2007 and is broadly consistent with biological needs. African countries have become major recipients of external assistance; however, countries where P vivax continues to pose threats to control ambitions are not as well funded. 21 countries have reached adequate assistance to provide a comprehensive suite of interventions by 2009, including 12 countries in Africa. However, this assistance was inadequate for 50 countries representing 61% of the worldwide population at risk of malaria-including ten countries in Africa and five in Asia that coincidentally are some of the poorest countries. Approval of donor funding for malaria control does not correlate with GDP. INTERPRETATION: Funding for malaria control worldwide is 60% lower than the US$4·9 billion needed for comprehensive control in 2010; this includes funding shortfalls for a wide range of countries with different numbers of people at risk and different levels of domestic income. More efficient targeting of financial resources against biological need and national income should create a more equitable investment portfolio that with increased commitments will guarantee sustained financing of control in countries most at risk and least able to support themselves. FUNDING: Wellcome Trust.

Hay SI, Gething PW, Snow RW. 2010. India's invisible malaria burden. Lancet, 376 (9754), pp. 1716-1717. | Citations: 33 (Web of Science Lite) | Read more

Ali S, Najmi MH, Tarning J, Lindegardh N. 2010. Pharmacokinetics of artemether and dihydroartemisinin in healthy Pakistani male volunteers treated with artemether-lumefantrine. Malar J, 9 (1), pp. 275. | Citations: 20 (Scopus) | Show Abstract | Read more

BACKGROUND: Artemether-lumefantrine is one of the most widely used anti-malarial drug combinations in the world with excellent tolerability and cure rates in adult and paediatric patients with uncomplicated falciparum malaria. The aim of this study was to evaluate the pharmacokinetics of artemether and its active metabolite, dihydroartemisinin, in healthy Pakistani volunteers. METHODS: Twelve healthy male Pakistani subjects, aged 20 to 50, were recruited into the study. A fixed oral combination of artemether-lumefantrine (80-480 mg) was given as a single oral dose. Frequent blood samples were collected and artemether and dihydroartemisinin were quantified in human plasma using solid-phase extraction and liquid chromatography coupled with tandem mass spectrometry. Drug concentration-time data were evaluated with non-compartmental analysis. RESULTS: Observed maximum concentrations (mean ± SD) of artemether and dihydroartemisinin were 184 ± 100 ng/mL and 126 ± 46 ng/mL, respectively. These concentrations were reached at 1.56 ± 0.68 hr and 1.69 ± 0.59 hr, respectively, after drug intake. The terminal elimination half-life of artemether and dihydroartemisinin were 2.00 ± 0.71 hr and 1.80 ± 0.31 hr, respectively. Apparent volume of distribution and oral clearance for artemether were estimated to 666 ± 220 L and 257 ± 140 L/hr. The same parameters were estimated to 702 ± 220 L and 269 ± 57 L/hr for dihydroartemisinin. CONCLUSIONS: The overall pharmacokinetic properties of artemether and dihydroartemisinin in healthy Pakistani subjects are comparable to healthy subjects and patients from other populations.

Muehlenbachs A, Fried M, McGready R, Harrington WE, Mutabingwa TK, Nosten F, Duffy PE. 2010. A novel histological grading scheme for placental malaria applied in areas of high and low malaria transmission. J Infect Dis, 202 (10), pp. 1608-1616. | Citations: 32 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Plasmodium falciparum-infected erythrocytes sequester in the placenta and elicit an inflammatory response that is harmful to both fetus and mother. Histologic measurements during placental malaria might provide surrogate end points for interventional trials, but existing histologic schemes capture limited complexity and are not consistently used among study sites. METHODS: Using frozen-section histologic evaluation in Tanzania (high-transmission area), we established a novel grading scheme to separately quantify inflammation and pigment deposition during placental malaria (n = 102). To generalize this method, formalin-fixed, paraffin-embedded placental samples from Karen women in Thailand (low-transmission area) were selected from among women with documented antenatal parasitemia who were near term (n = 18). RESULTS: In the Tanzanian cohort, the inflammation and pigment-deposition scores were independently associated with birth weight, and the inflammation score was associated with chemokine levels. In the smaller cohort from Thailand, both inflammation and pigment scores were associated with birth weight, and the pigment score had an inverse trend with the number of antenatal clinic visits. CONCLUSIONS: This semiquantitative pathological grading scheme is simple to implement and captures information that is associated with outcomes in Asia and Africa; therefore, it should facilitate the comparison and standardization of results among clinical trials across areas of differing endemicity.

Ha DTM, Lan NTN, Kiet VS, Wolbers M, Hang HTT, Day J, Hien NQ, Tien NA, An PT, Anh TT et al. 2010. Diagnosis of pulmonary tuberculosis in HIV-positive patients by microscopic observation drug susceptibility assay. J Clin Microbiol, 48 (12), pp. 4573-4579. | Citations: 13 (Scopus) | Show Abstract | Read more

The microscopic observation drug susceptibility assay (MODS) is a novel and promising test for the early diagnosis of tuberculosis (TB). We evaluated the MODS assay for the early diagnosis of TB in HIV-positive patients presenting to Pham Ngoc Thach Hospital for Tuberculosis and Lung Diseases in southern Vietnam. A total of 738 consecutive sputum samples collected from 307 HIV-positive individuals suspected of TB were tested by smear, MODS, and the mycobacteria growth indicator tube method (MGIT). The diagnostic sensitivity and specificity of MODS compared to the microbiological gold standard (either smear or MGIT) were 87 and 93%, respectively. The sensitivities of smear, MODS, and MGIT were 57, 71, and 75%, respectively, against clinical gold standard (MODS versus smear, P<0.001; MODS versus MGIT, P=0.03). The clinical gold standard was defined as patients who had a clinical examination and treatment consistent with TB, with or without microbiological confirmation. For the diagnosis of smear-negative patients, the sensitivities of MODS and MGIT were 38 and 45%, respectively (P=0.08). The median times to detection using MODS and MGIT were 8 and 11 days, respectively, and they were 11 and 17 days, respectively, for smear-negative samples. The original bacterial/fungal contamination rate of MODS was 1.1%, while it was 2.6% for MGIT. The cross-contamination rate of MODS was 4.7%. In conclusion, MODS is a sensitive, specific, and rapid test that is appropriate for the detection of HIV-associated TB; its cost and ease of use make it particularly useful in resource-limited settings.

Izzard L, Fuller A, Blacksell SD, Paris DH, Richards AL, Aukkanit N, Nguyen C, Jiang J, Fenwick S, Day NPJ et al. 2010. Isolation of a novel Orientia species (O. chuto sp. nov.) from a patient infected in Dubai. J Clin Microbiol, 48 (12), pp. 4404-4409. | Citations: 52 (Scopus) | Show Abstract | Read more

In July 2006, an Australian tourist returning from Dubai, in the United Arab Emirates (UAE), developed acute scrub typhus. Her signs and symptoms included fever, myalgia, headache, rash, and eschar. Orientia tsutsugamushi serology demonstrated a 4-fold rise in antibody titers in paired serum collections (1:512 to 1:8,192), with the sera reacting strongest against the Gilliam strain antigen. An Orientia species was isolated by the in vitro culture of the patient's acute blood taken prior to antibiotic treatment. The gene sequencing of the 16S rRNA gene (rrs), partial 56-kDa gene, and the full open reading frame 47-kDa gene was performed, and comparisons of this new Orientia sp. isolate to previously characterized strains demonstrated significant sequence diversity. The closest homology to the rrs sequence of the new Orientia sp. isolate was with three strains of O. tsutsugamushi (Ikeda, Kato, and Karp), with a nucleotide sequence similarity of 98.5%. The closest homology to the 47-kDa gene sequence was with O. tsutsugamushi strain Gilliam, with a nucleotide similarity of 82.3%, while the closest homology to the 56-kDa gene sequence was with O. tsutsugamushi strain TA686, with a nucleotide similarity of 53.1%. The molecular divergence and geographically unique origin lead us to believe that this organism should be considered a novel species. Therefore, we have proposed the name "Orientia chuto," and the prototype strain of this species is strain Dubai, named after the location in which the patient was infected.

Trung DT, Thao LTT, Hien TT, Hung NT, Vinh NN, Hien PTD, Chinh NT, Simmons C, Wills B. 2010. Liver involvement associated with dengue infection in adults in Vietnam. Am J Trop Med Hyg, 83 (4), pp. 774-780. | Citations: 86 (Scopus) | Show Abstract | Read more

Globally, the number of adults hospitalized with dengue has increased markedly in recent years. It has been suggested that hepatic dysfunction is more significant in this group than among children. We describe the spectrum and evolution of disease manifestations among 644 adults with dengue who were prospectively recruited on admission to a major infectious disease hospital in southern Vietnam and compare them with a group of patients with similar illnesses not caused by dengue. Transaminase levels increased in virtually all dengue patients and correlated with other markers of disease severity. However, peak enzyme values usually occurred later than other complications. Clinically severe liver involvement was infrequent and idiosyncratic, but usually resulted in severe bleeding. Chronic co-infection with hepatitis B was associated with modestly but significantly increased levels of alanine aminotransferase, but did not otherwise impact the clinical picture.

Noor AM, Alegana VA, Patil AP, Snow RW. 2010. Predicting the unmet need for biologically targeted coverage of insecticide-treated nets in Kenya. Am J Trop Med Hyg, 83 (4), pp. 854-860. | Citations: 12 (Web of Science Lite) | Show Abstract | Read more

In some countries the biological targeting of universal malaria prevention may offer optimal impact on disease and significant cost-savings compared with approaches that presume universal risk. Spatially defined data on coverage of treated nets from recent national household surveys in Kenya were used within a Bayesian geostatistical framework to predict treated net coverage nationally. When combined with the distributions of malaria risk and population an estimated 8.1 million people were not protected with treated nets in 2010 in biologically defined priority areas. After adjusting for the proportion of nets in use that were not long lasting, an estimated 5.5 to 6.3 million long-lasting treated nets would be required to achieve universal coverage in 2010 in Kenya in at-risk areas compared with 16.4 to 18.1 million nets if not restricted to areas of greatest malaria risk. In Kenya, this evidence-based approach could save the national program at least 55 million US dollars.

Färnert A, Gwer S, Berkley JA. 2010. Clinical considerations for antibiotic choices in the treatment of severe malaria. Trends Parasitol, 26 (10), pp. 465-466. | Citations: 3 (Scopus) | Read more

Smithuis F, Kyaw MK, Phe O, Win T, Aung PP, Oo APP, Naing AL, Nyo MY, Myint NZH, Imwong M et al. 2010. Effectiveness of five artemisinin combination regimens with or without primaquine in uncomplicated falciparum malaria: an open-label randomised trial. Lancet Infect Dis, 10 (10), pp. 673-681. | Citations: 115 (Scopus) | Show Abstract | Read more

BACKGROUND: Artemisinin-combination therapy (ACT) is recommended as first-line treatment of falciparum malaria throughout the world, and fixed-dose combinations are preferred by WHO; whether a single gametocytocidal dose of primaquine should be added is unknown. We aimed to compare effectiveness of four fixed-dose ACTs and a loose tablet combination of artesunate and mefloquine, and assess the addition of a single gametocytocidal dose of primaquine. METHODS: In an open-label randomised trial in clinics in Rakhine state, Kachin state, and Shan state in Myanmar (Burma) between Dec 30, 2008, and March 20, 2009, we compared the effectiveness of all four WHO-recommended fixed-dose ACTs (artesunate-mefloquine, artesunate-amodiaquine, dihydroartemisinin-piperaquine, artemether-lumefantrine) and loose artesunate-mefloquine in Burmese adults and children. Eligible patients were those who presented to the clinics with acute uncomplicated Plasmodium falciparum malaria or mixed infection, who were older than 6 months, and who weighed more than 5 kg. Treatments were randomised in equal numbers within blocks of 50 and allocation was in sealed envelopes. All patients were also randomly assigned to receive either a single dose of primaquine 0·75 mg base/kg or not. Patients were followed up for 63 days. Treatment groups were compared by analysis of variance and multiple logistic regression. The primary outcome was the 63 day recrudescence rate. This study is registered with clinicaltrials.gov, number NCT00902811. FINDINGS: 155 patients received artesunate-amodiaquine, 162 artemether-lumefantrine, 169 artesunate-mefloquine, 161 loose artesunate-mefloquine, and 161 dihydroartemisinin-piperaquine. By day 63 of follow-up, 14 patients (9·4%; 95% CI 5·7-15·3%) on artesunate-amodiaquine had recrudescent P falciparum infections, a rate significantly higher than for artemether-lumefantrine (two patients; 1·4%; 0·3-5·3; p=0·0013), fixed-dose artesunate-mefloquine (0 patients; 0-2·3; p<0·0001), loose artesunate-mefloquine (two patients; 1·3%; 0·3-5·3; p=0·0018), and dihydroartemisinin-piperaquine (two patients 1·3%; 0·3-5·2%; p=0·0012). Hazard ratios for re-infection (95% CI) after artesunate-amodiaquine were 3·2 (1·3-8·0) compared with the two artesunate-mefloquine groups (p=0·01), 2·6 (1·0-6-0) compared with artemether-lumefantrine (p=0·04), and 2·3 (0·9-6·0) compared with dihydroartemisinin-piperaquine (p=0·08). Mixed falciparum and vivax infections were common: 129 (16%) had a mixed infection at presentation and 330 (41%) patients had one or more episodes of Plasmodium vivax infection during follow-up. The addition of a single dose of primaquine (0·75 mg/kg) reduced P falciparum gametocyte carriage substantially: rate ratio 11·9 (95% CI 7·4-20·5). All regimens were well tolerated. Adverse events were reported by 599 patients, most commonly vomiting and dizziness. Other side-effects were less common and were not related to a specific treatment. INTERPRETATION: Artesunate-amodiaquine should not be used in Myanmar, because the other ACTs are substantially more effective. Artesunate-mefloquine provided the greatest post-treatment suppression of malaria. Adding a single dose of primaquine would substantially reduce transmission potential. Vivax malaria, not recurrent falciparum malaria, is the main complication after treatment of P falciparum infections in this region. FUNDING: Médecins sans Frontières (Holland) and the Wellcome Trust Mahidol University Oxford Tropical Medicine Research Programme.

Koh GCKW, Limmathurotsakul D. 2010. Gamma interferon supplementation for melioidosis. Antimicrob Agents Chemother, 54 (10), pp. 4520. | Citations: 3 (Web of Science Lite) | Read more

Ochola LI, Tetteh KKA, Stewart LB, Riitho V, Marsh K, Conway DJ. 2010. Allele frequency-based and polymorphism-versus-divergence indices of balancing selection in a new filtered set of polymorphic genes in Plasmodium falciparum. Mol Biol Evol, 27 (10), pp. 2344-2351. | Citations: 43 (Scopus) | Show Abstract | Read more

Signatures of balancing selection operating on specific gene loci in endemic pathogens can identify candidate targets of naturally acquired immunity. In malaria parasites, several leading vaccine candidates convincingly show such signatures when subjected to several tests of neutrality, but the discovery of new targets affected by selection to a similar extent has been slow. A small minority of all genes are under such selection, as indicated by a recent study of 26 Plasmodium falciparum merozoite-stage genes that were not previously prioritized as vaccine candidates, of which only one (locus PF10_0348) showed a strong signature. Therefore, to focus discovery efforts on genes that are polymorphic, we scanned all available shotgun genome sequence data from laboratory lines of P. falciparum and chose six loci with more than five single nucleotide polymorphisms per kilobase (including PF10_0348) for in-depth frequency-based analyses in a Kenyan population (allele sample sizes >50 for each locus) and comparison of Hudson-Kreitman-Aguade (HKA) ratios of population diversity (π) to interspecific divergence (K) from the chimpanzee parasite Plasmodium reichenowi. Three of these (the msp3/6-like genes PF10_0348 and PF10_0355 and the surf(4.1) gene PFD1160w) showed exceptionally high positive values of Tajima's D and Fu and Li's F indices and have the highest HKA ratios, indicating that they are under balancing selection and should be prioritized for studies of their protein products as candidate targets of immunity. Combined with earlier results, there is now strong evidence that high HKA ratio (as well as the frequency-independent ratio of Watterson's /K) is predictive of high values of Tajima's D. Thus, the former offers value for use in genome-wide screening when numbers of genome sequences within a species are low or in combination with Tajima's D as a 2D test on large population genomic samples.

Salje J, Gayathri P, Löwe J. 2010. The ParMRC system: molecular mechanisms of plasmid segregation by actin-like filaments. Nat Rev Microbiol, 8 (10), pp. 683-692. | Citations: 61 (Scopus) | Show Abstract | Read more

The ParMRC plasmid partitioning apparatus is one of the best characterized systems for bacterial DNA segregation. Bundles of actin-like filaments are used to push plasmids to opposite poles of the cell, whereupon they are stably inherited on cell division. This plasmid-encoded system comprises just three components: an actin-like protein, ParM, a DNA-binding adaptor protein, ParR, and a centromere-like region, parC. The properties and interactions of these components have been finely tuned to enable ParM filaments to search the cell space for plasmids and then move ParR-parC-bound DNA molecules apart. In this Review, we look at some of the most exciting questions in the field concerning the exact molecular mechanisms by which the components of this self-contained system modulate one another's activity to achieve bipolar DNA segregation.

Price RN, Marfurt J, Chalfein F, Kenangalem E, Piera KA, Tjitra E, Anstey NM, Russell B. 2010. In vitro activity of pyronaridine against multidrug-resistant Plasmodium falciparum and Plasmodium vivax. Antimicrob Agents Chemother, 54 (12), pp. 5146-5150. | Citations: 24 (Scopus) | Show Abstract | Read more

Pyronaridine, a Mannich base antimalarial, has demonstrated high in vivo and in vitro efficacy against chloroquine-resistant Plasmodium falciparum. Although this drug has the potential to become a prominent artemisinin combination therapy, little is known about its efficacy against drug-resistant Plasmodium vivax. The in vitro antimalarial susceptibility of pyronaridine was assessed in multidrug-resistant P. vivax (n = 99) and P. falciparum (n = 90) isolates from Papua, Indonesia, using a schizont maturation assay. The median 50% inhibitory concentration (IC(50)) of pyronaridine was 1.92 nM (range, 0.24 to 13.8 nM) against P. falciparum and 2.58 nM (range, 0.13 to 43.6 nM) against P. vivax, with in vitro susceptibility correlating significantly with chloroquine, amodiaquine, and piperaquine (r(s) [Spearman's rank correlation coefficient] = 0.45 to 0.62; P < 0.001). P. falciparum parasites initially at trophozoite stage had higher IC(50)s of pyronaridine than those exposed at the ring stage (8.9 nM [range, 0.6 to 8.9 nM] versus 1.6 nM [range, 0.6 to 8.9 nM], respectively; P = 0.015), although this did not reach significance for P. vivax (4.7 nM [range, 1.4 to 18.7 nM] versus 2.5 nM [range, 1.4 to 15.6 nM], respectively; P = 0.085). The excellent in vitro efficacy of pyronaridine against both chloroquine-resistant P. vivax and P. falciparum highlights the suitability of the drug as a novel partner for artemisinin-based combination therapy in regions where the two species are coendemic.

Nosten F. 2010. Waking the sleeping beauty. J Infect Dis, 202 (9), pp. 1300-1301. | Citations: 12 (Web of Science Lite) | Read more

Faiz A, Ghose A, Ahsan F, Rahman R, Amin R, Hassan MU, Chowdhury AW, Kuch U, Rocha T, Harris JB et al. 2010. The greater black krait (Bungarus niger), a newly recognized cause of neuro-myotoxic snake bite envenoming in Bangladesh. Brain, 133 (11), pp. 3181-3193. | Citations: 29 (Scopus) | Show Abstract | Read more

Prospective studies of snake bite patients in Chittagong, Bangladesh, included five cases of bites by greater black kraits (Bungarus niger), proven by examination of the snakes that had been responsible. This species was previously known only from India, Nepal, Bhutan and Burma. The index case presented with descending flaccid paralysis typical of neurotoxic envenoming by all Bungarus species, but later developed generalized rhabdomyolysis (peak serum creatine kinase concentration 29,960 units/l) with myoglobinuria and acute renal failure from which he succumbed. Among the other four patients, one died of respiratory paralysis in a peripheral hospital and three recovered after developing paralysis, requiring mechanical ventilation in one patient. One patient suffered severe generalized myalgia and odynophagia associated with a modest increase in serum creatine kinase concentration. These are the first cases of Bungarus niger envenoming to be reported from any country. Generalized rhabdomyolysis has not been previously recognized as a feature of envenoming by any terrestrial Asian elapid snake, but a review of the literature suggests that venoms of some populations of Bungarus candidus and Bungarus multicinctus in Thailand and Vietnam may also have this effect in human victims. To investigate this unexpected property of Bungarus niger venom, venom from the snake responsible for one of the human cases of neuro-myotoxic envenoming was injected into one hind limb of rats and saline into the other under buprenorphine analgesia. All animals developed paralysis of the venom-injected limb within two hours. Twenty-four hours later, the soleus muscles were compared histopathologically and cytochemically. Results indicated a predominantly pre-synaptic action (β-bungarotoxins) of Bungarus niger venom at neuromuscular junctions, causing loss of synaptophysin and the degeneration of the terminal components of the motor innervation of rat skeletal muscle. There was oedema and necrosis of extrafusal muscle fibres in envenomed rat soleus muscles confirming the myotoxic effect of Bungarus niger venom, attributable to phospholipases A₂. This study has demonstrated that Bungarus niger is widely distributed in Bangladesh and confirms the risk of fatal neuro-myotoxic envenoming, especially as no specific antivenom is currently manufactured. The unexpected finding of rhabdomyolysis should prompt further investigation of the venom components responsible. The practical implications of having to treat patients with rhabdomyolysis and consequent acute renal failure, in addition to the more familiar respiratory failure associated with krait bite envenoming, should not be underestimated in a country that is poorly equipped to deal with such emergencies.

Wasunna B, Zurovac D, Bruce J, Jones C, Webster J, Snow RW. 2010. Health worker performance in the management of paediatric fevers following in-service training and exposure to job aids in Kenya. Malar J, 9 (1), pp. 261. | Citations: 22 (Scopus) | Show Abstract | Read more

BACKGROUND: Improving the way artemether-lumefantrine (AL) is provided to patients attending clinics is critical to maximize the benefit of this new medicine. In 2007, a new initiative was launched in one part of Kenya to improve malaria case-management through enhanced in-service training and provision of job aids. METHODS: An evaluation of the intervention using pre- and post-intervention cross sectional health facility surveys was conducted in Bondo district. The surveys included: audit of government health facilities, health worker structured interviews and exit interviews with caretakers of sick children below five years of age. The outcome indicators were the proportions of febrile children who had AL prescribed, AL dispensed, and four different dispensing and counseling tasks performed. RESULTS: At baseline 33 government health facilities, 48 health workers and 386 febrile child consultations were evaluated. At follow-up the same health facilities were surveyed and 36 health workers and 390 febrile child consultations evaluated. The findings show: 1) no health facility or health worker was exposed to all components of the intervention; 2) the proportion of health workers who received the enhanced in-service training was 67%; 3) the proportion of febrile children with uncomplicated malaria treated with the first-line anti-malarial drug, artemether-lumefantrine (AL), at health facilities where AL was in stock increased from 76.9% (95%CI: 69.4, 83.1) to 87.6% (95% CI: 82.5, 91.5); 4) there were modest but non-significant improvements in dispensing and counseling practices; and 5) when the analyses were restricted to health workers who received the enhanced in-service training and/or had received new guidelines and job aids, no significant improvements in reported case-management tasks were observed compared to baseline. CONCLUSION: In-service training and provision of job aids alone may not be adequate to improve the prescribing, dispensing and counseling tasks necessary to change malaria case-management practices and the inclusion of supervision and post-training follow-up should be considered in future clinical practice change initiatives.

Weinberger DM, Harboe ZB, Sanders EAM, Ndiritu M, Klugman KP, Rückinger S, Dagan R, Adegbola R, Cutts F, Johnson HL et al. 2010. Association of serotype with risk of death due to pneumococcal pneumonia: a meta-analysis. Clin Infect Dis, 51 (6), pp. 692-699. | Citations: 197 (Scopus) | Show Abstract | Read more

BACKGROUND: The 92 capsular serotypes of Streptococcus pneumoniae differ greatly in nasopharyngeal carriage prevalence, invasiveness, and disease incidence. There has been some debate, though, regarding whether serotype independently affects the outcome of invasive pneumococcal disease (IPD). Published studies have shown variable results with regard to case-fatality ratios for specific serotypes and the role of host factors in affecting these relationships. We evaluated whether risk of death due to IPD is a stable serotype-associated property across studies and then compared the pooled effect estimates with epidemiologic and biological correlates. METHODS: We performed a systematic review and meta-analysis of serotype-specific disease outcomes for patients with pneumonia and meningitis. Study-specific estimates of risk of death (risk ratio [RR]) were pooled from 9 studies that provided serotype-specific data on pneumonia and meningitis using a random-effects method with serotype 14 as the reference. Pooled RRs were compared with RRs from adults with low comorbidity scores to evaluate potential confounding by host factors. RESULTS: Significant differences were found in the RR estimates among serotypes in patients with bacteremic pneumonia. Overall, serotypes 1, 7F, and 8 were associated with decreased RRs, and serotypes 3, 6A, 6B, 9N, and 19F were associated with increased RRs. Outcomes among meningitis patients did not differ significantly among serotypes. Serotypes with increased RRs had a high carriage prevalence, had low invasiveness, and were more heavily encapsulated in vitro. CONCLUSIONS: These results suggest that IPD outcome, like other epidemiologic measures, is a stable serotype-associated property.

Baker S, Hanage WP, Holt KE. 2010. Navigating the future of bacterial molecular epidemiology. Curr Opin Microbiol, 13 (5), pp. 640-645. | Citations: 43 (Scopus) | Show Abstract | Read more

Technological advances in high-throughput genome sequencing have led to an enhanced appreciation of the genetic diversity found within populations of pathogenic bacteria. Methods based on single nucleotide polymorphisms (SNPs) and insertions or deletions (indels) build upon the framework established by multi-locus sequence typing (MLST) and permit a detailed, targeted analysis of variation within related organisms. Robust phylogenetics, when combined with epidemiologically informative data, can be applied to study ongoing temporal and geographical fluctuations in bacterial pathogens. As genome sequencing, SNP detection and geospatial information become more accessible these methods will continue to transform the way molecular epidemiology is used to study populations of bacterial pathogens.

Parry CM, Thuy CT, Dongol S, Karkey A, Vinh H, Chinh NT, Duy PT, Thieu Nga TV, Campbell JI, Van Minh Hoang N et al. 2010. Suitable disk antimicrobial susceptibility breakpoints defining Salmonella enterica serovar Typhi isolates with reduced susceptibility to fluoroquinolones. Antimicrob Agents Chemother, 54 (12), pp. 5201-5208. | Citations: 33 (Scopus) | Show Abstract | Read more

Infections with Salmonella enterica serovar Typhi isolates that have reduced susceptibility to ofloxacin (MIC ≥ 0.25 μg/ml) or ciprofloxacin (MIC ≥ 0.125 μg/ml) have been associated with a delayed response or clinical failure following treatment with these antimicrobials. These isolates are not detected as resistant using current disk susceptibility breakpoints. We examined 816 isolates of S. Typhi from seven Asian countries. Screening for nalidixic acid resistance (MIC ≥ 16 μg/ml) identified isolates with an ofloxacin MIC of ≥0.25 μg/ml with a sensitivity of 97.3% (253/260) and specificity of 99.3% (552/556). For isolates with a ciprofloxacin MIC of ≥0.125 μg/ml, the sensitivity was 92.9% (248/267) and specificity was 98.4% (540/549). A zone of inhibition of ≤28 mm around a 5-μg ofloxacin disc detected strains with an ofloxacin MIC of ≥0.25 μg/ml with a sensitivity of 94.6% (246/260) and specificity of 94.2% (524/556). A zone of inhibition of ≤30 mm detected isolates with a ciprofloxacin MIC of ≥0.125 μg/ml with a sensitivity of 94.0% (251/267) and specificity of 94.2% (517/549). An ofloxacin MIC of ≥0.25 μg/ml and a ciprofloxacin MIC of ≥0.125 μg/ml detected 74.5% (341/460) of isolates with an identified quinolone resistance-inducing mutation and 81.5% (331/406) of the most common mutant (carrying a serine-to-phenylalanine mutation at codon 83 in the gyrA gene). Screening for nalidixic acid resistance or ciprofloxacin and ofloxacin disk inhibition zone are suitable for detecting S. Typhi isolates with reduced fluoroquinolone susceptibility.

Basnyat B. 2010. Neglected hepatitis E and typhoid vaccines. Lancet, 376 (9744), pp. 869. | Citations: 3 (Web of Science Lite) | Read more

Price RN, Douglas NM. 2010. Maximising the public health benefit of antimalarials. Lancet Infect Dis, 10 (10), pp. 654-655. | Citations: 3 (Web of Science Lite) | Read more

Rottmann M, McNamara C, Yeung BKS, Lee MCS, Zou B, Russell B, Seitz P, Plouffe DM, Dharia NV, Tan J et al. 2010. Spiroindolones, a potent compound class for the treatment of malaria. Science, 329 (5996), pp. 1175-1180. | Citations: 593 (Scopus) | Show Abstract | Read more

Recent reports of increased tolerance to artemisinin derivatives--the most recently adopted class of antimalarials--have prompted a need for new treatments. The spirotetrahydro-beta-carbolines, or spiroindolones, are potent drugs that kill the blood stages of Plasmodium falciparum and Plasmodium vivax clinical isolates at low nanomolar concentration. Spiroindolones rapidly inhibit protein synthesis in P. falciparum, an effect that is ablated in parasites bearing nonsynonymous mutations in the gene encoding the P-type cation-transporter ATPase4 (PfATP4). The optimized spiroindolone NITD609 shows pharmacokinetic properties compatible with once-daily oral dosing and has single-dose efficacy in a rodent malaria model.

Wangdi K, Singhasivanon P, Silawan T, Lawpoolsri S, White NJ, Kaewkungwal J. 2010. Development of temporal modelling for forecasting and prediction of malaria infections using time-series and ARIMAX analyses: a case study in endemic districts of Bhutan. Malar J, 9 (1), pp. 251. | Citations: 47 (Scopus) | Show Abstract | Read more

BACKGROUND: Malaria still remains a public health problem in some districts of Bhutan despite marked reduction of cases in last few years. To strengthen the country's prevention and control measures, this study was carried out to develop forecasting and prediction models of malaria incidence in the endemic districts of Bhutan using time series and ARIMAX. METHODS: This study was carried out retrospectively using the monthly reported malaria cases from the health centres to Vector-borne Disease Control Programme (VDCP) and the meteorological data from Meteorological Unit, Department of Energy, Ministry of Economic Affairs. Time series analysis was performed on monthly malaria cases, from 1994 to 2008, in seven malaria endemic districts. The time series models derived from a multiplicative seasonal autoregressive integrated moving average (ARIMA) was deployed to identify the best model using data from 1994 to 2006. The best-fit model was selected for each individual district and for the overall endemic area was developed and the monthly cases from January to December 2009 and 2010 were forecasted. In developing the prediction model, the monthly reported malaria cases and the meteorological factors from 1996 to 2008 of the seven districts were analysed. The method of ARIMAX modelling was employed to determine predictors of malaria of the subsequent month. RESULTS: It was found that the ARIMA (p, d, q) (P, D, Q)s model (p and P representing the auto regressive and seasonal autoregressive; d and D representing the non-seasonal differences and seasonal differencing; and q and Q the moving average parameters and seasonal moving average parameters, respectively and s representing the length of the seasonal period) for the overall endemic districts was (2,1,1)(0,1,1)12; the modelling data from each district revealed two most common ARIMA models including (2,1,1)(0,1,1)12 and (1,1,1)(0,1,1)12. The forecasted monthly malaria cases from January to December 2009 and 2010 varied from 15 to 82 cases in 2009 and 67 to 149 cases in 2010, where population in 2009 was 285,375 and the expected population of 2010 to be 289,085. The ARIMAX model of monthly cases and climatic factors showed considerable variations among the different districts. In general, the mean maximum temperature lagged at one month was a strong positive predictor of an increased malaria cases for four districts. The monthly number of cases of the previous month was also a significant predictor in one district, whereas no variable could predict malaria cases for two districts. CONCLUSIONS: The ARIMA models of time-series analysis were useful in forecasting the number of cases in the endemic areas of Bhutan. There was no consistency in the predictors of malaria cases when using ARIMAX model with selected lag times and climatic predictors. The ARIMA forecasting models could be employed for planning and managing malaria prevention and control programme in Bhutan.

Chu ER, Weinstein SA, White J, Warrell DA. 2010. Venom ophthalmia caused by venoms of spitting elapid and other snakes: Report of ten cases with review of epidemiology, clinical features, pathophysiology and management. Toxicon, 56 (3), pp. 259-272. | Citations: 40 (Scopus) | Show Abstract | Read more

Venom ophthalmia caused by venoms of spitting elapid and other snakes: report of ten cases with review of epidemiology, clinical features, pathophysiology and management. Chu, ER, Weinstein, SA, White, J and Warrell, DA. Toxicon XX:xxx-xxx. We present ten cases of ocular injury following instillation into the eye of snake venoms or toxins by spitting elapids and other snakes. The natural history of spitting elapids and the toxinology of their venoms are reviewed together with the medical effects and management of venom ophthalmia in humans and domestic animals including both direct and allergic effects of venoms. Although the clinical features and management of envenoming following bites by spitting elapids (genera Naja and Hemachatus) are well documented, these snakes are also capable of "spraying" venom towards the eyes of predators, a defensive strategy that causes painful and potentially blinding ocular envenoming (venom ophthalmia). Little attention has been given to the detailed clinical description, clinical evolution and efficacy of treatment of venom ophthalmia and no clear management guidelines have been formulated. Knowledge of the pathophysiology of ocular envenoming is based largely on animal studies and a limited body of clinical information. A few cases of ocular exposure to venoms from crotaline viperids have also been described. Venom ophthalmia often presents with pain, hyperemia, blepharitis, blepharospasm and corneal erosions. Delay or lack of treatment may result in corneal opacity, hypopyon and/or blindness. When venom is "spat" into the eye, cranial nerve VII may be affected by local spread of venom but systemic envenoming has not been documented in human patients. Management of venom ophthalmia consists of: 1) urgent decontamination by copious irrigation 2) analgesia by vasoconstrictors with weak mydriatic activity (e.g. epinephrine) and limited topical administration of local anesthetics (e.g. tetracaine) 3) exclusion of corneal abrasions by fluorescein staining with a slit lamp examination and application of prophylactic topical antibiotics 4) prevention of posterior synechiae, ciliary spasm and discomfort with topical cycloplegics and 5) antihistamines in case of allergic kerato-conjunctivitis. Topical or intravenous antivenom and topical corticosteroids are contraindicated. Clinical outcome of venom ophthalmia is largely dependent on prompt treatment and appropriate follow-up.

Turner P, Turner CL, Watthanaworawit W, Carrara VI, Kapella BK, Painter J, Nosten FH. 2010. Influenza in refugees on the Thailand-Myanmar border, May-October 2009. Emerg Infect Dis, 16 (9), pp. 1366-1372. | Citations: 7 (Scopus) | Show Abstract | Read more

We describe the epidemiology of influenza virus infections in refugees in a camp in rural Southeast Asia during May-October 2009, the first 6 months after identification of pandemic (H1N1) 2009 in Thailand. Influenza A viruses were detected in 20% of patients who had influenza-like illness and in 23% of those who had clinical pneumonia. Seasonal influenza A (H1N1) was the predominant virus circulating during weeks 26-33 (June 25-August 29) and was subsequently replaced by the pandemic strain. A review of passive surveillance for acute respiratory infection did not show an increase in acute respiratory tract infection incidence associated with the arrival of pandemic (H1N1) 2009 in the camp.

Moore CE, Sengduangphachanh A, Thaojaikong T, Sirisouk J, Foster D, Phetsouvanh R, McGee L, Crook DW, Newton PN, Peacock SJ. 2010. Enhanced determination of Streptococcus pneumoniae serotypes associated with invasive disease in Laos by using a real-time polymerase chain reaction serotyping assay with cerebrospinal fluid. Am J Trop Med Hyg, 83 (3), pp. 451-457. | Citations: 21 (Web of Science Lite) | Show Abstract | Read more

A prospective hospital-based study was undertaken to define the incidence of invasive pneumococcal disease (IPD) and circulating serotypes in Laos. Of 10,799 patients with hemocultures and 353 patients with cerebrospinal fluid samples, 0.21% and 5.4%, respectively, were positive for Streptococcus pneumoniae, giving a total of 35 IPD patients. We developed a real-time polymerase chain reaction to detect serotypes represented in the 13-valent pneumococcal vaccine. A blinded evaluation comparing serotype as defined by the Quellung reaction versus the polymerase chain reaction demonstrated 100% concordance. The most frequent serotype (n = 33 patients) was 1 (n = 6), followed by serotypes 5, 6A/B/C, 14, and 23F. Serotypes represented in the 7-valent polysaccharide-protein conjugate vaccine (PCV-7) infected 39% of patients, with 73% coverage for the PCV-10 and PCV-13 vaccines. Although the sample size is small, these data suggest that the PCV-7 vaccine may have relatively low efficacy in Laos. Further studies are urgently needed to guide pneumococcal vaccine policy in Laos.

Soepandi PZ, Burhan E, Mangunnegoro H, Nawas A, Aditama TY, Partakusuma L, Isbaniah F, Ikhsan M, Swidarmoko B, Sutiyoso A et al. 2010. Clinical course of avian influenza A(H5N1) in patients at the Persahabatan Hospital, Jakarta, Indonesia, 2005-2008. Chest, 138 (3), pp. 665-673. | Citations: 15 (Scopus) | Show Abstract | Read more

BACKGROUND: Limited understanding of the presentation and course of influenza A(H5N1) infection in humans hinders evidence-based management. METHODS: We reviewed the case records of patients admitted to the Persahabatan Hospital (RSP), Jakarta, Indonesia, with influenza A(H5N1) confirmed by real-time polymerase chain reaction. RESULTS: Twenty-two previously well patients, aged 3 to 47 years (median 24.5 years), were identified. All attended a clinic or hospital after a median of 2 days of illness (range 0-7). Times to first dose of oseltamivir (three died before receiving oseltamivir) were 2 to 12 days (median 7 days), administered mostly (n = 15) at RSP. Nineteen patients required mechanical ventilation. Deaths numbered 18 (case fatality = 82%) occurring within hours to 6 days of RSP admission, corresponding to 6 to 16 days of illness. Admission hyperglycemia ( >or= 140 mg/dL), unrelated to steroids or known underlying diabetes mellitus, and elevated D-dimer levels (0.81-5.2 mg/L, upper limit of normal < 0.5 mg/L) were present in 14/21 (67%) and 20/21 (95%) patients, respectively. Fibrinogen concentrations were mostly low/normal at 129.9 to 517.9 mg/dL (median 241.1, normal 200-400 mg/dL), whereas C-reactive protein (9/11) and ferritin (6/8) levels were increased. Risk factors for death (univariate analysis) included: (1) increased D-dimers, (2) hyperglycema, (3) increased urea, (4) more extensive chest radiograph shadowing, and (5) lower admission oxygen saturation. CONCLUSIONS: Early diagnosis and effective treatment of human influenza A(H5N1) infection remains challenging. Most patients were referred late with advanced disease. Oseltamivir had limited clinical impact. Elevated D-dimer levels, consistent with fibrinolysis, and hyperglycemia warrant more research to determine their underlying mechanisms and optimal treatment.

Berkley JA, Munywoki P, Nokes DJ. 2010. Severe Pneumonia Among Kenyan Infants and Children Reply JAMA-JOURNAL OF THE AMERICAN MEDICAL ASSOCIATION, 304 (9), pp. 964-965. | Read more

Willemsen I, Cooper B, van Buitenen C, Winters M, Andriesse G, Kluytmans J. 2010. Improving quinolone use in hospitals by using a bundle of interventions in an interrupted time series analysis. Antimicrob Agents Chemother, 54 (9), pp. 3763-3769. | Citations: 16 (Scopus) | Show Abstract | Read more

The objectives of the present study were to determine the effects of multiple targeted interventions on the level of use of quinolones and the observed rates of resistance to quinolones in Escherichia coli isolates from hospitalized patients. A bundle consisting of four interventions to improve the use of quinolones was implemented. The outcome was measured from the monthly levels of use of intravenous (i.v.) and oral quinolones and the susceptibility patterns for E. coli isolates from hospitalized patients. Statistical analyses were performed using segmented regression analysis and segmented Poisson regression models. Before the bundle was implemented, the annual use of quinolones was 2.7 defined daily doses (DDDs)/100 patient days. After the interventions, in 2007, this was reduced to 1.7 DDDs/100 patient days. The first intervention, a switch from i.v. to oral medication, was associated with a stepwise reduction in i.v. quinolone use of 71 prescribed daily doses (PDDs) per month (95% confidence interval [CI] = 47 to 95 PDDs/month, P < 0.001). Intervention 2, introduction of a new antibiotic guideline and education program, was associated with a stepwise reduction in the overall use of quinolones (reduction, 107 PDDs/month [95% CI = 58 to 156 PDDs/month). Before the interventions the quinolone resistance rate was increasing, on average, by 4.6% (95% CI = 2.6 to 6.1%) per year. This increase leveled off, which was associated with intervention 2 and intervention 4, active monitoring of prescriptions and feedback. Trends in resistance to other antimicrobial agents did not change. This study showed that the hospital-wide use of quinolones can be significantly reduced by an active policy consisting of multiple interventions. There was also a stepwise reduction in the rate of quinolone resistance associated with the bundle of interventions.

Dong B-Q, Yang J, Wang X-Y, Gong J, von Seidlein L, Wang M-L, Lin M, Liao H-Z, Ochiai RL, Xu Z-Y et al. 2010. Trends and disease burden of enteric fever in Guangxi province, China, 1994-2004. Bull World Health Organ, 88 (9), pp. 689-696. | Citations: 29 (Scopus) | Show Abstract | Read more

OBJECTIVE: To determine the burden of enteric fever through trends in morbidity and mortality, bacterial species and antimicrobial resistance in Guangxi, a southern, subtropical, coastal province of China with a disproportionally large burden of enteric fever. METHODS: Data on morbidity and mortality caused by enteric fever between 1994 and 2004 were extracted from the Guangxi Center for Disease Control and Prevention. Laboratory-based surveillance and outbreak investigations were integrated with reports of notifiable infectious diseases to estimate the bacterial species-specific incidence of enteric fever. To adjust for underreporting, survey data were collected from three prefectures that represent the hyper-, moderate- and low-endemic regions of Guangxi province. FINDINGS: In Guangxi province, enteric fever incidence rate varied over the study period, with a peak of 13.5 cases per 100 000 population in 1995 and a low of 6.5 in 2003. The disease occurred most frequently during the summer and autumn months and in the group aged 10-49 years. The incidence of enteric fever varied by region within Guangxi province. During the 11-year period covered by the study, 61 outbreaks of enteric fever were reported, and Salmonella paratyphi A (SPA) became the predominant causative agent in the province. CONCLUSION: Prospective studies may provide a better understanding of the reason for the shifting epidemiology of enteric fever in Guangxi province. Given the emergence of resistance to first- and second-line antimicrobials for the treatment of enteric fever, a bivalent vaccine against both SPA and S. typhi would facilitate for disease control.

Kanungo S, Tsuzuki A, Deen JL, Lopez AL, Rajendran K, Manna B, Sur D, Kim DR, Gupta VK, Ochiai RL et al. 2010. Use of verbal autopsy to determine mortality patterns in an urban slum in Kolkata, India. Bull World Health Organ, 88 (9), pp. 667-674. | Citations: 17 (Scopus) | Show Abstract | Read more

OBJECTIVE: To define mortality patterns in an urban slum in Kolkata, India, in the context of a cholera and typhoid fever project. METHODS: In a well-defined population that was under surveillance for 18 months, we followed a dynamic cohort of 63 788 residents whose households were visited monthly by community health workers to identify deaths. Trained physicians performed verbal autopsies and experienced senior physicians assigned the primary cause of death according to the International classification of diseases, 10th edition. We tabulated causes of death in accordance with Global Burden of Disease 2000 categories and assessed overall and cause-specific mortality rates per age group and gender. FINDINGS: During 87 921 person-years of follow-up, we recorded 544 deaths. This gave an overall mortality rate of 6.2 per 1000 person-years. We assigned a cause to 89% (482/544) of the deaths. The leading causes of death, in descending order, were cardiovascular diseases (especially among adults aged over 40 years), cancer, respiratory ailments and digestive disorders. Most deaths in children under 5 years of age were caused by tuberculosis, respiratory infections and diarrhoeal diseases. CONCLUSION: Although the most common causes of death in children were infectious, non-communicable diseases were predominant among adults. There is a need for continuing interventions against infectious diseases in addition to new and innovative strategies to combat non-infectious conditions.

Gertsch JH, Lipman GS, Holck PS, Merritt A, Mulcahy A, Fisher RS, Basnyat B, Allison E, Hanzelka K, Hazan A et al. 2010. Prospective, double-blind, randomized, placebo-controlled comparison of acetazolamide versus ibuprofen for prophylaxis against high altitude headache: the Headache Evaluation at Altitude Trial (HEAT). Wilderness Environ Med, 21 (3), pp. 236-243. | Citations: 46 (Scopus) | Show Abstract | Read more

OBJECTIVE: High altitude headache (HAH) is the most common neurological complaint at altitude and the defining component of acute mountain sickness (AMS). However, there is a paucity of literature concerning its prevention. Toward this end, we initiated a prospective, double-blind, randomized, placebo-controlled trial in the Nepal Himalaya designed to compare the effectiveness of ibuprofen and acetazolamide for the prevention of HAH. METHODS: Three hundred forty-three healthy western trekkers were recruited at altitudes of 4280 m and 4358 m and assigned to receive ibuprofen 600 mg, acetazolamide 85 mg, or placebo 3 times daily before continued ascent to 4928 m. Outcome measures included headache incidence and severity, AMS incidence and severity on the Lake Louise AMS Questionnaire (LLQ), and visual analog scale (VAS). RESULTS: Two hundred sixty-five of 343 subjects completed the trial. HAH incidence was similar when treated with acetazolamide (27.1%) or ibuprofen (27.5%; P = .95), and both agents were significantly more effective than placebo (45.3%; P = .01). AMS incidence was similar when treated with acetazolamide (18.8%) or ibuprofen (13.7%; P = .34), and both agents were significantly more effective than placebo (28.6%; P = .03). In fully compliant participants, moderate or severe headache incidence was similar when treated with acetazolamide (3.8%) or ibuprofen (4.7%; P = .79), and both agents were significantly more effective than placebo (13.5%; P = .03). CONCLUSIONS: Ibuprofen and acetazolamide were similarly effective in preventing HAH. Ibuprofen was similar to acetazolamide in preventing symptoms of AMS, an interesting finding that implies a potentially new approach to prevention of cerebral forms of acute altitude illness.

Warren JR, Day KJ, Paton C, Warren DE, Mabotuwana TDS, Gu Y, Adnan M, Reedy W. 2010. Implementations of health information technologies with consumers as users: Findings from a systematic review Health Care and Informatics Review Online, 14 (3), pp. 2-28. | Citations: 2 (Scopus) | Show Abstract

Background: A systematic review of evaluations of innovative eHealth implementations was funded by the New Zealand Ministry of Health to inform information strategy. A key trend of interest to the Ministry was person-centered healthcare, including systems where health consumers use health information technology (IT) directly. Herein we report, analyze and reflect on the review findings with respect to such systems. Objectives: To review the nature and extent of known successes of health IT with consumers as users. Methods: Queries for evaluations of innovative eHealth implementations were submitted to MEDLINE, EMBASE, PsycINFO, CINAHL and Business Source Premier for articles appearing between 2003 and early 2009 and filtered on inclusion criteria of reporting actual implementations (i.e., use), innovativeness, evaluation (interpreted generously) and scaleability. Substitutions were made where more recent superior studies of the same or closely related projects could be found. Results: 100 of 1413 retrieved articles met the inclusion criteria; 47 of these involved consumers as users of a component of the evaluated system. Systems that provided messaging between the patient and their regular care provider met with satisfaction and good uptake. There were improved chronic disease outcomes in 11 of 15 education/self-management systems and 2 of 3 home telemonitoring systems where measurement of such outcomes was reported; a further 3 systems targeting the family members of individuals with chronic conditions as principal users all showed positive well-being outcomes for the caregivers. Conclusions: There have been a number of demonstrated instances of clear successes in both uptake and outcome for health IT interventions involving consumers as users, particularly for chronic condition management. However, compelling demonstrations (in terms of methods and sample size) remain isolated. More study is needed to assess the transferability of the demonstrated successes to greater scale, diverse contexts of deployment and to other conditions. Better keywords and more systematic reporting, particularly with respect to implementation and evaluation status, would aid similar reviews in the future.

Hamers RL, Siwale M, Wallis CL, Labib M, van Hasselt R, Stevens WS, Schuurman R, Wensing AMJ, Van Vugt M, Rinke de Wit TF, PharmAccess African Studies to Evaluate Resistance. 2010. HIV-1 drug resistance mutations are present in six percent of persons initiating antiretroviral therapy in Lusaka, Zambia. J Acquir Immune Defic Syndr, 55 (1), pp. 95-101. | Citations: 27 (Scopus) | Show Abstract | Read more

OBJECTIVE: To assess the mutational patterns and factors associated with baseline drug-resistant HIV-1 present at initiation of first-line antiretroviral therapy (ART) at 3 sites in Lusaka, Zambia, in 2007-2008. METHODS: Population sequencing of the HIV-1 pol gene was performed in the PharmAccess African Studies to Evaluate Resistance Monitoring cohort. Drug resistance-associated mutations (DRMs) were identified using the WHO 2009 Surveillance DRM list. Multiple logistic regression was used to assess factors associated with baseline resistance. RESULTS: The overall prevalence of baseline resistance was 5.7% [31 of 548 participants; 95% confidence interval (CI): 3.9 to 7.9]; the prevalence of DRMs associated with nucleoside reverse transcriptase inhibitors (NRTIs), nonnucleoside reverse transcriptase inhibitors (NNRTIs) and protease inhibitors was 1.1%, 4.0%, and 1.1%, respectively. Resistance prevalence was 5.2% (27 of 523) in antiretroviral-naive and 16.0% (4 of 25) in antiretroviral-experienced (ie, previous use of ART or antiretroviral prophylaxis for prevention of mother-to-child transmission) participants (P = 0.022). Dual-class resistance to NRTIs and NNRTIs was observed in 0.6% of participants. HIV-1 subtype C was identified in 98.0% (537 of 548) of participants. Prior antiretroviral experience (odds ratio: 4.32, CI: 1.34 to 14.0, P = 0.015) and hemoglobin level (highest tertile versus lowest tertile odds ratio: 2.74, CI: 1.09 to 6.89, P = 0.033) were independently associated with baseline resistance. CONCLUSIONS: Baseline resistance may compromise the response to standard NNRTI-based first-line ART in 6% of patients in Lusaka, Zambia. Continuous resistance monitoring is warranted to maintain individual and population-level ART effectiveness.

Limmathurotsakul D, Jamsen K, Arayawichanont A, Simpson JA, White LJ, Lee SJ, Wuthiekanun V, Chantratita N, Cheng A, Day NPJ et al. 2010. Defining the true sensitivity of culture for the diagnosis of melioidosis using Bayesian latent class models. PLoS One, 5 (8), pp. e12485. | Citations: 57 (Scopus) | Show Abstract | Read more

BACKGROUND: Culture remains the diagnostic gold standard for many bacterial infections, and the method against which other tests are often evaluated. Specificity of culture is 100% if the pathogenic organism is not found in healthy subjects, but the sensitivity of culture is more difficult to determine and may be low. Here, we apply Bayesian latent class models (LCMs) to data from patients with a single Gram-negative bacterial infection and define the true sensitivity of culture together with the impact of misclassification by culture on the reported accuracy of alternative diagnostic tests. METHODS/PRINCIPAL FINDINGS: Data from published studies describing the application of five diagnostic tests (culture and four serological tests) to a patient cohort with suspected melioidosis were re-analysed using several Bayesian LCMs. Sensitivities, specificities, and positive and negative predictive values (PPVs and NPVs) were calculated. Of 320 patients with suspected melioidosis, 119 (37%) had culture confirmed melioidosis. Using the final model (Bayesian LCM with conditional dependence between serological tests), the sensitivity of culture was estimated to be 60.2%. Prediction accuracy of the final model was assessed using a classification tool to grade patients according to the likelihood of melioidosis, which indicated that an estimated disease prevalence of 61.6% was credible. Estimates of sensitivities, specificities, PPVs and NPVs of four serological tests were significantly different from previously published values in which culture was used as the gold standard. CONCLUSIONS/SIGNIFICANCE: Culture has low sensitivity and low NPV for the diagnosis of melioidosis and is an imperfect gold standard against which to evaluate alternative tests. Models should be used to support the evaluation of diagnostic tests with an imperfect gold standard. It is likely that the poor sensitivity/specificity of culture is not specific for melioidosis, but rather a generic problem for many bacterial and fungal infections.

Osier FHA, Weedall GD, Verra F, Murungi L, Tetteh KKA, Bull P, Faber BW, Remarque E, Thomas A, Marsh K, Conway DJ. 2010. Allelic diversity and naturally acquired allele-specific antibody responses to Plasmodium falciparum apical membrane antigen 1 in Kenya. Infect Immun, 78 (11), pp. 4625-4633. | Citations: 33 (Scopus) | Show Abstract | Read more

Although Plasmodium falciparum apical membrane antigen 1 (AMA1) is a leading malaria vaccine candidate, extensive allelic diversity may compromise its vaccine potential. We have previously shown that naturally acquired antibodies to AMA1 were associated with protection from clinical malaria in this Kenyan population. To assess the impact of allelic diversity on naturally acquired immunity, we first sequenced the ectodomain-encoding region of P. falciparum ama1 from subjects with asymptomatic, mild, and severe malaria and measured allele frequency distributions. We then measured antibodies to three allelic AMA1 proteins (AMA1_3D7, AMA1_FVO, and AMA1_HB3) and used competition enzyme-linked immunosorbent assays (ELISAs) to analyze allele-specific antibodies. Seventy-eight unique haplotypes were identified from 129 alleles sampled. No clustering of allelic haplotypes with disease severity or year of sampling was observed. Differences in nucleotide frequencies in clinical (severe plus mild malaria) versus asymptomatic infections were observed at 16 polymorphic positions. Allele frequency distributions were indicative of balancing selection, with the strongest signature being identified in domain III (Tajima's D = 2.51; P < 0.05). Antibody reactivities to each of the three allelic AMA1 proteins were highly correlated (P < 0.001 for all pairwise comparisons). Although antibodies to conserved epitopes were abundant, 48% of selected children with anti-AMA1 IgG (n = 106) had detectable reactivity to allele-specific epitopes as determined by a competition ELISA. Antibodies to both conserved and allele-specific epitopes in AMA1 may contribute to clinical protection.

Anderson TJC, Williams JT, Nair S, Sudimack D, Barends M, Jaidee A, Price RN, Nosten F. 2010. Inferred relatedness and heritability in malaria parasites Proceedings. Biological sciences / The Royal Society, 277 (1693), pp. 2531-2540. | Citations: 1 (Scopus) | Show Abstract | Read more

Malaria parasites vary in phenotypic traits of biomedical or biological interest such as growth rate, virulence, sex ratio and drug resistance, and there is considerable interest in identifying the genes that underlie this variation. An important first step is to determine trait heritability (H(2)). We evaluate two approaches to measuring H(2) in natural parasite populations using relatedness inferred from genetic marker data. We collected single-clone Plasmodium falciparum infections from 185 patients from the Thailand-Burma border, monitored parasite clearance following treatment with artemisinin combination therapy (ACT), measured resistance to six antimalarial drugs and genotyped parasites using 335 microsatellites. We found strong relatedness structure. There were 27 groups of two to eight clonally identical (CI) parasites, and 74 per cent of parasites showed significant relatedness to one or more other parasites. Initially, we used matrices of allele sharing and variance components (VC) methods to estimate H(2). Inhibitory concentrations (IC(50)) for six drugs showed significant H(2) (0.24 to 0.79, p = 0.06 to 2.85 x 10(-9)), demonstrating that this study design has adequate power. However, a phenotype of current interest--parasite clearance following ACT--showed no detectable heritability (H(2) = 0-0.09, ns) in this population. The existence of CI parasites allows the use of a simple ANOVA approach for quantifying H(2), analogous to that used in human twin studies. This gave similar results to the VC method and requires considerably less genotyping information. We conclude (i) that H(2) can be effectively measured in malaria parasite populations using minimal genotype data, allowing rational design of genome-wide association studies; and (ii) while drug response (IC(50)) shows significant H(2), parasite clearance following ACT was not heritable in the population studied.

Tanomsing N, Imwong M, Theppabutr S, Pukrittayakamee S, Day NPJ, White NJ, Snounou G. 2010. Accurate and sensitive detection of Plasmodium species in humans by use of the dihydrofolate reductase-thymidylate synthase linker region. J Clin Microbiol, 48 (10), pp. 3735-3737. | Citations: 8 (Web of Science Lite) | Show Abstract | Read more

A nested-PCR protocol based on the linker region of the Plasmodium dihydrofolate reductase-thymidylate synthase gene (dhfr-ts) was developed. This provides highly sensitive specific detection and identification of the five parasite species that infect humans.

Moïsi JC, Kabuka J, Mitingi D, Levine OS, Scott JAG. 2010. Spatial and socio-demographic predictors of time-to-immunization in a rural area in Kenya: Is equity attainable? Vaccine, 28 (35), pp. 5725-5730. | Citations: 29 (Web of Science Lite) | Show Abstract | Read more

We conducted a vaccine coverage survey in Kilifi District, Kenya in order to identify predictors of childhood immunization. We calculated travel time to vaccine clinics and examined its relationship to immunization coverage and timeliness among the 2169 enrolled children (median age: 12.5 months). 86% had vaccine cards available, >95% had received three doses of DTP-HepB-Hib and polio vaccines and 88% of measles. Travel time did not affect vaccination coverage or timeliness. The Kenyan EPI reaches nearly all children in Kilifi and delays in vaccination are few, suggesting that vaccines will have maximal impact on child morbidity and mortality.

Guerra CA, Howes RE, Patil AP, Gething PW, Van Boeckel TP, Temperley WH, Kabaria CW, Tatem AJ, Manh BH, Elyazar IRF et al. 2010. The international limits and population at risk of Plasmodium vivax transmission in 2009. PLoS Negl Trop Dis, 4 (8), pp. e774. | Citations: 306 (Scopus) | Show Abstract | Read more

BACKGROUND: A research priority for Plasmodium vivax malaria is to improve our understanding of the spatial distribution of risk and its relationship with the burden of P. vivax disease in human populations. The aim of the research outlined in this article is to provide a contemporary evidence-based map of the global spatial extent of P. vivax malaria, together with estimates of the human population at risk (PAR) of any level of transmission in 2009. METHODOLOGY: The most recent P. vivax case-reporting data that could be obtained for all malaria endemic countries were used to classify risk into three classes: malaria free, unstable (<0.1 case per 1,000 people per annum (p.a.)) and stable (> or =0.1 case per 1,000 p.a.) P. vivax malaria transmission. Risk areas were further constrained using temperature and aridity data based upon their relationship with parasite and vector bionomics. Medical intelligence was used to refine the spatial extent of risk in specific areas where transmission was reported to be absent (e.g., large urban areas and malaria-free islands). The PAR under each level of transmission was then derived by combining the categorical risk map with a high resolution population surface adjusted to 2009. The exclusion of large Duffy negative populations in Africa from the PAR totals was achieved using independent modelling of the gene frequency of this genetic trait. It was estimated that 2.85 billion people were exposed to some risk of P. vivax transmission in 2009, with 57.1% of them living in areas of unstable transmission. The vast majority (2.59 billion, 91.0%) were located in Central and South East (CSE) Asia, whilst the remainder were located in America (0.16 billion, 5.5%) and in the Africa+ region (0.10 billion, 3.5%). Despite evidence of ubiquitous risk of P. vivax infection in Africa, the very high prevalence of Duffy negativity throughout Central and West Africa reduced the PAR estimates substantially. CONCLUSIONS: After more than a century of development and control, P. vivax remains more widely distributed than P. falciparum and is a potential cause of morbidity and mortality amongst the 2.85 billion people living at risk of infection, the majority of whom are in the tropical belt of CSE Asia. The probability of infection is reduced massively across Africa by the frequency of the Duffy negative trait, but transmission does occur on the continent and is a concern for Duffy positive locals and travellers. The final map provides the spatial limits on which the endemicity of P. vivax transmission can be mapped to support future cartographic-based burden estimations.

Blacksell SD, Jenjaroen K, Phetsouvanh R, Tanganuchitcharnchai A, Phouminh P, Phongmany S, Day NPJ, Newton PN. 2010. Accuracy of rapid IgM-based immunochromatographic and immunoblot assays for diagnosis of acute scrub typhus and murine typhus infections in Laos. Am J Trop Med Hyg, 83 (2), pp. 365-369. | Citations: 21 (Scopus) | Show Abstract | Read more

We studied the diagnostic accuracy of a rapid immunochromatographic test (ICT) for detection of IgM against scrub typhus (ST ICT) and an immunoblot test for the detection of IgM against murine typhus (MT IBT) by using admission serum samples from 1,030 febrile patients in Laos. Sensitivity and specificity for the ST ICT determined by using the diagnostic criteria of a four-fold increase in IgM against Orientia tsutsugamushi between paired samples were 23.8% (95% confidence interval [CI] = 15.9-33.3%) and 86.2% (95% CI = 84.1-88.6%), respectively. Sensitivity and specificity for the ST ICT determined by using an admission IgM titer > or = 1:400 were 39.1% (95% CI = 34.1-44.2%) and 99.5% (95% CI = 98.7-99.9%), respectively. Sensitivity and specificity for the MT IBT determined by using the criteria of a four-fold increase in IgM against Rickettsia typhi between paired serum samples were 61.2% (95% CI = 53.7-68.3%) and 86.5% (95% CI = 84.1-88.8%), respectively. Sensitivity and specificity for the MT IBT determined by using an admission IgM titer > or = 1:400 were 54.6% (95% CI = 49.1-60.0%) and 94.1% (95% CI = 92.0-95.7%), respectively. Both assays had relatively good specificity but low sensitivity and thus have limited utility for admission diagnosis.

Lang T. 2010. Diverse ethics of translational research in the developing world. Am J Bioeth, 10 (8), pp. 41-42. | Citations: 2 (Scopus) | Read more

Medana IM, Day NPJ, Roberts R, Sachanonta N, Turley H, Pongponratn E, Hien TT, White NJ, Turner GDH. 2010. Induction of the vascular endothelial growth factor pathway in the brain of adults with fatal falciparum malaria is a non-specific response to severe disease. Histopathology, 57 (2), pp. 282-294. | Citations: 13 (Scopus) | Show Abstract | Read more

AIMS: Pathological or neuroprotective mechanisms in the brain in severe malaria may arise from microvascular obstruction with malaria-parasitized erythrocytes. This study aimed to investigate the role of hypoxia and induction of the vascular endothelial growth factor (VEGF) pathway in the neuropathophysiology of severe malaria. METHODS AND RESULTS: Immunohistochemistry was performed on post mortem brain tissue sections from 20 cases of severe malaria and examined for the expression of transcriptional regulators of VEGF [hypoxia-inducible factor-1 alpha (HIF-1alpha), HIF-2alpha], DEC-1, VEGF, VEGF receptors 1 and 2, and the activated, phosphorylated VEGF receptor 2 (pKDR). HIFs showed limited protein expression and/or translocation to cell nuclei in severe malaria, but DEC-1, which is more stable and regulated by HIF-1alpha, was observed. There was heterogeneous expression of VEGF and its receptors in severe malaria and non-malarial disease controls. pKDR expression on vessels was greater in malaria cases than in controls but did not correlate with parasite sequestration. VEGF uptake by malaria parasites was observed. CONCLUSIONS: VEGF and its receptor expression levels in severe malaria reflect a non-specific response to severe systemic disease. Potential manipulation of events at the vasculature by the parasite requires further investigation.

Isanaka S, Roederer T, Djibo A, Luquero FJ, Nombela N, Guerin PJ, Grais RF. 2010. Reducing wasting in young children with preventive supplementation: a cohort study in Niger. Pediatrics, 126 (2), pp. e442-e450. | Citations: 17 (Scopus) | Show Abstract | Read more

OBJECTIVE: To compare the incidence of wasting, stunting, and mortality among children aged 6 to 36 months who are receiving preventive supplementation with either ready-to-use supplementary foods (RUSFs) or ready-to-use therapeutic foods (RUTFs). SUBJECTS AND METHODS: Children aged 6 to 36 months in 12 villages of Maradi, Niger, (n = 1645) received a monthly distribution of RUSFs (247 kcal [3 spoons] per day) for 6 months or RUTFs (500-kcal sachet per day) for 4 months. We compared the incidence of wasting, stunting, and mortality among children who received preventive supplementation with RUSFs versus RUTFs. RESULTS: The effectiveness of RUSF supplementation depended on receipt of a previous preventive intervention. In villages in which a preventive supplementation program was previously implemented, the RUSF strategy was associated with a 46% (95% confidence interval [CI]: 6%-69%) and 59% (95% CI: 17%-80%) reduction in wasting and severe wasting, respectively. In contrast, in villages in which the previous intervention was not implemented, we found no difference in the incidence of wasting or severe wasting according to type of supplementation. Compared with the RUTF strategy, the RUSF strategy was associated with a 19% (95% CI: 0%-34%) reduction in stunting overall. CONCLUSION: We found that the relative performance of a 6-month RUSF supplementation strategy versus a 4-month RUTF strategy varied with receipt of a previous nutritional intervention. Contextual factors will continue to be important in determining the dose and duration of supplementation that will be most effective, acceptable, and sustainable for a given setting.

Song Y, Roumagnac P, Weill F-X, Wain J, Dolecek C, Mazzoni CJ, Holt KE, Achtman M. 2010. A multiplex single nucleotide polymorphism typing assay for detecting mutations that result in decreased fluoroquinolone susceptibility in Salmonella enterica serovars Typhi and Paratyphi A. J Antimicrob Chemother, 65 (8), pp. 1631-1641. | Citations: 26 (Scopus) | Show Abstract | Read more

OBJECTIVES: Decreased susceptibility to fluoroquinolones has become a major problem for the successful therapy of human infections caused by Salmonella enterica, especially the life-threatening typhoid and paratyphoid fevers. METHODS: By using Luminex xTAG beads, we developed a rapid, reliable and cost-effective multiplexed genotyping assay for simultaneously detecting 11 mutations in gyrA, gyrB and parE of S. enterica serovars Typhi and Paratyphi A that result in nalidixic acid resistance (Nal(R)) and/or decreased susceptibility to fluoroquinolones. RESULTS: This assay yielded unambiguous single nucleotide polymorphism calls on extracted DNA from 292 isolates of Salmonella Typhi (Nal(R) = 223 and Nal(S) = 69) and 106 isolates of Salmonella Paratyphi A (Nal(R) = 24 and Nal(S) = 82). All of the 247 Nal(R) Salmonella Typhi and Salmonella Paratyphi A isolates were found to harbour at least one of the target mutations, with GyrA Phe-83 as the most common one (143/223 for Salmonella Typhi and 18/24 for Salmonella Paratyphi A). We also identified three GyrB mutations in eight Nal(S) Salmonella Typhi isolates (six for GyrB Phe-464, one for GyrB Leu-465 and one for GyrB Asp-466), and mutations GyrB Phe-464 and GyrB Asp-466 seem to be related to the decreased ciprofloxacin susceptibility phenotype in Salmonella Typhi. This assay can also be used directly on boiled single colonies. CONCLUSIONS: The assay presented here would be useful for clinical and reference laboratories to rapidly screen quinolone-resistant isolates of Salmonella Typhi and Salmonella Paratyphi A, and decipher the underlying genetic changes for epidemiological purposes.

van der Windt GJW, Wiersinga WJ, Wieland CW, Tjia ICSI, Day NP, Peacock SJ, Florquin S, van der Poll T. 2010. Osteopontin impairs host defense during established gram-negative sepsis caused by Burkholderia pseudomallei (melioidosis). PLoS Negl Trop Dis, 4 (8), pp. e806-e806. | Citations: 11 (Scopus) | Show Abstract | Read more

BACKGROUND: Melioidosis, caused by infection with Burkholderia (B.) pseudomallei, is a severe illness that is endemic in Southeast Asia. Osteopontin (OPN) is a phosphorylated glycoprotein that is involved in several immune responses including induction of T-helper 1 cytokines and recruitment of inflammatory cells. METHODOLOGY AND PRINCIPAL FINDINGS: OPN levels were determined in plasma from 33 melioidosis patients and 31 healthy controls, and in wild-type (WT) mice intranasally infected with B. pseudomallei. OPN function was studied in experimental murine melioidosis using WT and OPN knockout (KO) mice. Plasma OPN levels were elevated in patients with severe melioidosis, even more so in patients who went on to die. In patients who recovered plasma OPN concentrations had decreased after treatment. In experimental melioidosis in mice plasma and pulmonary OPN levels were also increased. Whereas WT and OPN KO mice were indistinguishable during the first 24 hours after infection, after 72 hours OPN KO mice demonstrated reduced bacterial numbers in their lungs, diminished pulmonary tissue injury, especially due to less necrosis, and decreased neutrophil infiltration. Moreover, OPN KO mice displayed a delayed mortality as compared to WT mice. OPN deficiency did not influence the induction of proinflammatory cytokines. CONCLUSIONS: These data suggest that sustained production of OPN impairs host defense during established septic melioidosis.

Guzman MG, Jaenisch T, Gaczkowski R, Ty Hang VT, Sekaran SD, Kroeger A, Vazquez S, Ruiz D, Martinez E, Mercado JC et al. 2010. Multi-country evaluation of the sensitivity and specificity of two commercially-available NS1 ELISA assays for dengue diagnosis. PLoS Negl Trop Dis, 4 (8), pp. e811-e811. | Citations: 86 (Scopus) | Show Abstract | Read more

BACKGROUND: Early diagnosis of dengue can assist patient triage and management and prevent unnecessary treatments and interventions. Commercially available assays that detect the dengue virus protein NS1 in the plasma/serum of patients offers the possibility of early and rapid diagnosis. METHODOLOGY/PRINCIPAL FINDINGS: The sensitivity and specificity of the Pan-E Dengue Early ELISA and the Platelia Dengue NS1 Ag assays were compared against a reference diagnosis in 1385 patients in 6 countries in Asia and the Americas. Platelia was more sensitive (66%) than Pan-E (52%) in confirmed dengue cases. Sensitivity varied by geographic region, with both assays generally being more sensitive in patients from SE Asia than the Americas. Both kits were more sensitive for specimens collected within the first few days of illness onset relative to later time points. Pan-E and Platelia were both 100% specific in febrile patients without evidence of acute dengue. In patients with other confirmed diagnoses and healthy blood donors, Platelia was more specific (100%) than Pan-E (90%). For Platelia, when either the NS1 test or the IgM test on the acute sample was positive, the sensitivity versus the reference result was 82% in samples collected in the first four days of fever. NS1 sensitivity was not associated to disease severity (DF or DHF) in the Platelia test, whereas a trend for higher sensitivity in DHF cases was seen in the Pan-E test (however combined with lower overall sensitivity). CONCLUSIONS/SIGNIFICANCE: Collectively, this multi-country study suggests that the best performing NS1 assay (Platelia) had moderate sensitivity (median 64%, range 34-76%) and high specificity (100%) for the diagnosis of dengue. The poor sensitivity of the evaluated assays in some geographical regions suggests further assessments are needed. The combination of NS1 and IgM detection in samples collected in the first few days of fever increased the overall dengue diagnostic sensitivity.

Achoki R, Opiyo N, English M. 2010. Mini-review: Management of hypoglycaemia in children aged 0-59 months. J Trop Pediatr, 56 (4), pp. 227-234. | Citations: 19 (Scopus) | Show Abstract | Read more

Hypoglycaemia is associated with poor prognosis in many severe childhood illnesses especially in sub-Saharan Africa where the prevalence of malaria, diarrhoea and malnutrition remains high. Uncertainty, however, still persists regarding the significance, definition and management of childhood hypoglycaemia. As a step towards defining optimal, evidence-based diagnostic and management criteria, we (i) reviewed the evidence underlying current recommendations for the management of hypoglycaemia, and (ii) analysed a large set of data on blood glucose levels and associated outcomes of paediatric admissions in a rural hospital over an 11-year period. Current definitions and treatment protocols for hypoglycaemia are based on observational data and expert opinion. Future large pragmatic randomized trials would help define optimal treatment thresholds. Emerging evidence suggests that sublingual sugar is a feasible and effective therapy for correction of hypoglycaemia, and should be considered where intravenous glucose is delayed or impossible.

Salje J. 2010. Plasmid segregation: how to survive as an extra piece of DNA. Crit Rev Biochem Mol Biol, 45 (4), pp. 296-317. | Citations: 27 (Scopus) | Show Abstract | Read more

Non-essential extra-chromosomal DNA elements such as plasmids are responsible for their own propagation in dividing host cells, and one means to ensure this is to carry a miniature active segregation system reminiscent of the mitotic spindle. Plasmids that are maintained at low numbers in prokaryotic cells have developed a range of such active partitioning systems, which are characterized by an impressive simplicity and efficiency and which are united by the use of dynamic, nucleotide-driven filaments to separate and position DNA molecules. A comparison of different plasmid segregation systems reveals (i) how unrelated filament-forming and DNA-binding proteins have been adopted and modified to create a range of simple DNA segregating complexes and (ii) how subtle changes in the few components of these DNA segregation machines has led to a remarkable diversity in the molecular mechanisms of closely related segregation systems. Here, our current understanding of plasmid segregation systems is reviewed and compared with other DNA segregation systems, and this is extended by a discussion of basic principles of plasmid segregation systems, evolutionary implications and the relationship between an autonomous DNA element and its host cell.

Khan MI, Ochiai RL, von Seidlein L, Dong B, Bhattacharya SK, Agtini MD, Bhutta ZA, Do GC, Ali M, Kim DR et al. 2010. Non-typhoidal Salmonella rates in febrile children at sites in five Asian countries. Trop Med Int Health, 15 (8), pp. 960-963. | Citations: 18 (Scopus) | Show Abstract | Read more

There is increased recognition of non-typhoidal Salmonella (NTS) as a major cause of severe febrile illness in sub-Saharan Africa. However, little is known about community-based incidence of NTS in Asia. In a multicentre, community-based prospective Salmonella surveillance study, we identified a total of six NTS cases: three in Karachi, Pakistan, one in Kolkata, India, and two in North Jakarta, Indonesia. No NTS cases were identified in Hechi, People's Republic of China, and Hue, Viet Nam. Three cases were in children under 3 years, and one case was in a child aged 10 years and one in a child aged 15 years. Only one case was an adult (29 years). The highest incidence of NTS infection was in Karachi (7.2 culture-proven NTS cases per 100,000 person years in age group of 2-15 years). However, in comparison with sub-Saharan Africa, the NTS burden in Asia appears rather limited.

Li A, Russell B, Renia L, Lek-Uthai U, Nosten F, Lim CT. 2010. High density of 'spiky' excrescences covering the surface of an erythrocyte infected with Plasmodium malariae. Br J Haematol, 151 (1), pp. 1. | Citations: 5 (Scopus) | Read more

Valecha N, Phyo AP, Mayxay M, Newton PN, Krudsood S, Keomany S, Khanthavong M, Pongvongsa T, Ruangveerayuth R, Uthaisil C et al. 2010. An open-label, randomised study of dihydroartemisinin-piperaquine versus artesunate-mefloquine for falciparum malaria in Asia. PLoS One, 5 (7), pp. e11880. | Citations: 52 (Scopus) | Show Abstract | Read more

BACKGROUND: The artemisinin-based combination treatment (ACT) of dihydroartemisinin (DHA) and piperaquine (PQP) is a promising novel anti-malarial drug effective against multi-drug resistant falciparum malaria. The aim of this study was to show non-inferiority of DHA/PQP vs. artesunate-mefloquine (AS+MQ) in Asia. METHODS AND FINDINGS: This was an open-label, randomised, non-inferiority, 63-day follow-up study conducted in Thailand, Laos and India. Patients aged 3 months to 65 years with Plasmodium falciparum mono-infection or mixed infection were randomised with an allocation ratio of 2:1 to a fixed-dose DHA/PQP combination tablet (adults: 40 mg/320 mg; children: 20 mg/160 [DOSAGE ERROR CORRECTED] mg; n = 769) or loose combination of AS+MQ (AS: 50 mg, MQ: 250 mg; n = 381). The cumulative doses of study treatment over the 3 days were of about 6.75 mg/kg of DHA and 54 mg/kg of PQP and about 12 mg/kg of AS and 25 mg/kg of MQ. Doses were rounded up to the nearest half tablet. The primary endpoint was day-63 polymerase chain reaction (PCR) genotype-corrected cure rate. Results were 87.9% for DHA/PQP and 86.6% for AS+MQ in the intention-to-treat (ITT; 97.5% one-sided confidence interval, CI: >-2.87%), and 98.7% and 97.0%, respectively, in the per protocol population (97.5% CI: >-0.39%). No country effect was observed. Kaplan-Meier estimates of proportions of patients with new infections on day 63 (secondary endpoint) were significantly lower for DHA/PQP than AS+MQ: 22.7% versus 30.3% (p = 0.0042; ITT). Overall gametocyte prevalence (days 7 to 63; secondary endpoint), measured as person-gametocyte-weeks, was significantly higher for DHA/PQP than AS+MQ (10.15% versus 4.88%; p = 0.003; ITT). Fifteen serious adverse events were reported, 12 (1.6%) in DHA/PQP and three (0.8%) in AS+MQ, among which six (0.8%) were considered related to DHA/PQP and three (0.8%) to AS+MQ. CONCLUSIONS: DHA/PQP was a highly efficacious drug for P. falciparum malaria in areas where multidrug parasites are prevalent. The DHA/PQP combination can play an important role in the first-line treatment of uncomplicated falciparum malaria. TRIAL REGISTRATION: Controlled-Trials.com ISRCTN81306618.

Tran TH, Nguyen TD, Nguyen TT, Ninh TTV, Tran NBC, Nguyen VMH, Tran TTN, Cao TT, Pham VM, Nguyen TCB et al. 2010. A randomised trial evaluating the safety and immunogenicity of the novel single oral dose typhoid vaccine M01ZH09 in healthy Vietnamese children. PLoS One, 5 (7), pp. e11778. | Citations: 26 (Scopus) | Show Abstract | Read more

BACKGROUND: The emergence of drug resistant typhoid fever is a major public health problem, especially in Asia. An oral single dose typhoid vaccine would have major advantages. M01ZH09 is a live oral single dose candidate typhoid vaccine containing Salmonella enterica serovar Typhi (Ty2 aroC(-)ssaV(-)) ZH9 with two independently attenuating deletions. Studies in healthy adults demonstrated immunogenicity and an acceptable safety profile. OBJECTIVES: We conducted a randomised placebo controlled, single-blind trial to evaluate the safety and immunogenicity of M01ZH09 in healthy Vietnamese children aged 5 to 14 years. METHODS: Subjects were randomly assigned to receive either a nominal dose of 5x10(9) CFU of M01ZH09 or placebo and were followed up for 28 days. The primary safety outcome was the proportion of subjects with any adverse event attributed to M01ZH09. The primary immunogenicity endpoint was the proportion of subjects who showed a positive immune response to M01ZH09 in the Salmonella Typhi lipopolysaccharide (LPS) specific serum IgA and IgG ELISA. PRINCIPAL FINDINGS: One hundred and fifty-one children were enrolled, 101 subjects received M01ZH09 and 50 subjects received placebo. An intention to treat analysis was conducted. There were no serious adverse events and no bacteraemias. In the M01ZH09 group, 26 (26%; 95% CI, 18-5%) of 101 subjects experienced adverse events compared to 11 (22%; 95% CI, 12-36%) of 50 subjects in the placebo group (odds ratio (OR) [95%CI] = 1.23 [0.550-2.747]; p = 0.691). Faecal shedding of S. Typhi (Ty2 aroC(-)ssaV(-)) ZH9 was detected in 51 (51%; 95% CI, 41-61%) of 100 M01ZH09 subjects. No shedding was detected beyond day 3. A positive immune response, defined as 70% increase (1.7 fold change) in LPS specific serum IgG (day 14 or 28) and/or 50% increase (1.5 fold change) in LPS specific serum IgA (day 7 or 14) from baseline was detected in 98 (97%; 95% CI, 92-99%) of 101 M01ZH09 recipients and 8 (16%; 95% CI, 7-29%) of 50 placebo recipients. Twenty-eight (100%; 95% CI, 88-100%) of 28 vaccine recipients who were evaluated in the LPS specific IgA ELISPOT assay showed a positive response compared to none of the 14 placebo recipients tested. CONCLUSIONS: This was the first phase II trial of a novel oral candidate typhoid vaccine in children in an endemic country. M01ZH09 had an appropriate safety profile and was immunogenic in children. TRIAL REGISTRATION: Controlled-trials.com ISRCTN91111837.

Sanders EJ, Thiong'o AN, Okuku HS, Mwambi J, Priddy F, Shafi J, de Vries H, McClelland RS, Graham SM. 2010. High prevalence of Chlamydia trachomatis and Neisseria gonorrhoeae infections among HIV-1 negative men who have sex with men in coastal Kenya. Sex Transm Infect, 86 (6), pp. 440-441. | Citations: 17 (Web of Science Lite) | Show Abstract | Read more

OBJECTIVES: To assess the burden of Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) in high-risk HIV-1 negative men who have sex with men (MSM) in Africa. METHODS: Before the start of a pre-exposure prophylaxis trial, HIV-1 negative volunteers were screened for sexually transmitted infection (STI) including CT and NG, using a highly sensitive and specific nucleic acid amplification test. Samples positive for CT by Aptima testing, were evaluated for the presence of lymphogranuloma venereum (LGV) serovars using an in-house PCR assay. All men were asked to submit a urine specimen, and all had a rectal swab collected by a clinician. Men were asked if they had dysuria, urethral or rectal discharge, or rectal pain. RESULTS: 43 HIV-1 negative MSM were screened, of whom 13 reported sex with men only; the majority (27/43) reported sex work. One volunteer had dysuria and another, rectal pain. Eleven MSM (26%, 95% CI 14% to 41%) had infections with either or both pathogens. Homosexual men had a higher prevalence of any infection than bisexual men (46% vs 17%, p=0.04), and all cases of rectal infections, including one with CT, two with NG and two with CT/NG co-infection. All patients with CT were negative for LGV. One patient with a rectal NG infection reported rectal pain. CONCLUSIONS: A remarkably high burden of STI infection was found among HIV-1 negative MSM. Most (12/13) infections, including three of four rectal NG infections, were subclinical. These findings suggest that high-risk MSM will benefit from effective STI screening in Kenya.

Cohen JM, Moonen B, Snow RW, Smith DL. 2010. How absolute is zero? An evaluation of historical and current definitions of malaria elimination. Malar J, 9 (1), pp. 213. | Citations: 72 (Scopus) | Show Abstract | Read more

Decisions to eliminate malaria from all or part of a country involve a complex set of factors, and this complexity is compounded by ambiguity surrounding some of the key terminology, most notably "control" and "elimination." It is impossible to forecast resource and operational requirements accurately if endpoints have not been defined clearly, yet even during the Global Malaria Eradication Program, debate raged over the precise definition of "eradication." Analogous deliberations regarding the meaning of "elimination" and "control" are basically nonexistent today despite these terms' core importance to programme planning. To advance the contemporary debate about these issues, this paper presents a historical review of commonly used terms, including control, elimination, and eradication, to help contextualize current understanding of these concepts. The review has been supported by analysis of the underlying mathematical concepts on which these definitions are based through simple branching process models that describe the proliferation of malaria cases following importation. Through this analysis, the importance of pragmatic definitions that are useful for providing malaria control and elimination programmes with a practical set of strategic milestones is emphasized, and it is argued that current conceptions of elimination in particular fail to achieve these requirements. To provide all countries with precise targets, new conceptual definitions are suggested to more precisely describe the old goals of "control" - here more exactly named "controlled low-endemic malaria" - and "elimination." Additionally, it is argued that a third state, called "controlled non-endemic malaria," is required to describe the epidemiological condition in which endemic transmission has been interrupted, but malaria resulting from onwards transmission from imported infections continues to occur at a sufficiently high level that elimination has not been achieved. Finally, guidelines are discussed for deriving the separate operational definitions and metrics that will be required to make these concepts relevant, measurable, and achievable for a particular environment.

Marsh VM, Kamuya DM, Mlamba AM, Williams TN, Molyneux SS. 2010. Experiences with community engagement and informed consent in a genetic cohort study of severe childhood diseases in Kenya. BMC Med Ethics, 11 (1), pp. 13. | Citations: 45 (Scopus) | Show Abstract | Read more

BACKGROUND: The potential contribution of community engagement to addressing ethical challenges for international biomedical research is well described, but there is relatively little documented experience of community engagement to inform its development in practice. This paper draws on experiences around community engagement and informed consent during a genetic cohort study in Kenya to contribute to understanding the strengths and challenges of community engagement in supporting ethical research practice, focusing on issues of communication, the role of field workers in 'doing ethics' on the ground and the challenges of community consultation. METHODS: The findings are based on action research methods, including analysis of community engagement documentation and the observations of the authors closely involved in their development and implementation. Qualitative and quantitative content analysis has been used for documentation of staff meetings and trainings, a meeting with 24 community leaders, and 40 large public and 70 small community group meetings. Meeting minutes from a purposive sample of six community representative groups have been analysed using a thematic framework approach. RESULTS: Field workers described challenges around misunderstandings about research, perceived pressure for recruitment and challenges in explaining the study. During consultation, leaders expressed support for the study and screening for sickle cell disease. In community meetings, there was a common interpretation of research as medical care. Concerns centred on unfamiliar procedures. After explanations of study procedures to leaders and community members, few questions were asked about export of samples or the archiving of samples for future research. CONCLUSIONS: Community engagement enabled researchers to take account of staff and community opinions and issues during the study and adapt messages and methods to address emerging ethical challenges. Field workers conducting informed consent faced complex issues and their understanding, attitudes and communication skills were key influences on ethical practice. Community consultation was a challenging concept to put into practice, illustrating the complexity of assessing information needs and levels of deliberation that are appropriate to a given study.

Trinh KX, Khac QL, Trinh LX, Warrell DA. 2010. Hyponatraemia, rhabdomyolysis, alterations in blood pressure and persistent mydriasis in patients envenomed by Malayan kraits (Bungarus candidus) in southern Viet Nam. Toxicon, 56 (6), pp. 1070-1075. | Citations: 19 (Scopus) | Show Abstract | Read more

Between 1998 and 2007, 42 patients admitted to Choray hospital, Ho Chi Minh City, and to two hospitals in adjacent regions in southern Viet Nam brought the Malayan kraits (Bungarus candidus) that had been responsible for biting them. Half of the patients had been bitten while they were asleep. Fang marks and numbness were the only local features of the bites. Common signs of neurotoxic envenoming included bilateral ptosis, persistently dilated pupils, limb weakness, breathlessness, hypersalivation, dysphonia and dysphagia. Thirty patients (71.4%) required endotracheal intubation of whom all but one were mechanically ventilated. Fourteen patients (33.3%) developed hypertension, 13 (31.0%) shock, 31 (73.8%) hyponatraemia (plasma sodium concentration < 130 mEq/l) and 30 (71.4%) showed evidence of mild rhabdomyolysis (peak plasma creatine kinase concentration 1375 +/- 140 micro/l). None developed acute kidney injury. All the patients were treated with a new monospecific B. candidus antivenom. There were no fatalities. Hyponatraemia has been reported previously in victims of Chinese kraits (Bungarus multicinctus) in northern Viet Nam and rhabdomyolysis in patients envenomed by B. niger in Bangladesh. These features of envenoming pose new problems for the management of krait bite cases in South east Asia and should stimulate a search for the causative venom toxins.

Chau TT, Mai NH, Phu NH, Nghia HD, Chuong LV, Sinh DX, Duong VA, Diep PT, Campbell JI, Baker S et al. 2010. A prospective descriptive study of cryptococcal meningitis in HIV uninfected patients in Vietnam - high prevalence of Cryptococcus neoformans var grubii in the absence of underlying disease. BMC Infect Dis, 10 (1), pp. 199. | Citations: 51 (Scopus) | Show Abstract | Read more

BACKGROUND: Most cases of cryptococcal meningitis occur in patients with HIV infection: the course and outcome of disease in the apparently immunocompetent is much more poorly understood. We describe a cohort of HIV uninfected Vietnamese patients with cryptococcal meningitis in whom underlying disease is uncommon, and relate presenting features of patients and the characteristics of the infecting species to outcome. METHODS: A prospective descriptive study of HIV negative patients with cryptococcal meningitis based at the Hospital for Tropical Diseases, Ho Chi Minh City. All patients had comprehensive clinical assessment at baseline, were cared for by a dedicated study team, and were followed up for 2 years. Clinical presentation was compared by infecting isolate and outcome. RESULTS: 57 patients were studied. Cryptococcus neoformans var grubii molecular type VN1 caused 70% of infections; C. gattii accounted for the rest. Most patients did not have underlying disease (81%), and the rate of underlying disease did not differ by infecting species. 11 patients died while in-patients (19.3%). Independent predictors of death were age > or = 60 years and a history of convulsions (odds ratios and 95% confidence intervals 8.7 (1 - 76), and 16.1 (1.6 - 161) respectively). Residual visual impairment was common, affecting 25 of 46 survivors (54.3%). Infecting species did not influence clinical phenotype or outcome. The minimum inhibitory concentrations of flucytosine and amphotericin B were significantly higher for C. neoformans var grubii compared with C. gattii (p < 0.001 and p = 0.01 respectively). CONCLUSION: In HIV uninfected individuals in Vietnam, cryptococcal meningitis occurs predominantly in people with no clear predisposing factor and is most commonly due to C. neoformans var grubii. The rates of mortality and visual loss are high and independent of infecting species. There are detectable differences in susceptibility to commonly used antifungal drugs between species, but the clinical significance of this is not clear.

Bejon P, Williams TN, Liljander A, Noor AM, Wambua J, Ogada E, Olotu A, Osier FHA, Hay SI, Färnert A, Marsh K. 2010. Stable and unstable malaria hotspots in longitudinal cohort studies in Kenya. PLoS Med, 7 (7), pp. e1000304. | Citations: 126 (Scopus) | Show Abstract | Read more

BACKGROUND: Infectious diseases often demonstrate heterogeneity of transmission among host populations. This heterogeneity reduces the efficacy of control strategies, but also implies that focusing control strategies on "hotspots" of transmission could be highly effective. METHODS AND FINDINGS: In order to identify hotspots of malaria transmission, we analysed longitudinal data on febrile malaria episodes, asymptomatic parasitaemia, and antibody titres over 12 y from 256 homesteads in three study areas in Kilifi District on the Kenyan coast. We examined heterogeneity by homestead, and identified groups of homesteads that formed hotspots using a spatial scan statistic. Two types of statistically significant hotspots were detected; stable hotspots of asymptomatic parasitaemia and unstable hotspots of febrile malaria. The stable hotspots were associated with higher average AMA-1 antibody titres than the unstable clusters (optical density [OD] = 1.24, 95% confidence interval [CI] 1.02-1.47 versus OD = 1.1, 95% CI 0.88-1.33) and lower mean ages of febrile malaria episodes (5.8 y, 95% CI 5.6-6.0 versus 5.91 y, 95% CI 5.7-6.1). A falling gradient of febrile malaria incidence was identified in the penumbrae of both hotspots. Hotspots were associated with AMA-1 titres, but not seroconversion rates. In order to target control measures, homesteads at risk of febrile malaria could be predicted by identifying the 20% of homesteads that experienced an episode of febrile malaria during one month in the dry season. That 20% subsequently experienced 65% of all febrile malaria episodes during the following year. A definition based on remote sensing data was 81% sensitive and 63% specific for the stable hotspots of asymptomatic malaria. CONCLUSIONS: Hotspots of asymptomatic parasitaemia are stable over time, but hotspots of febrile malaria are unstable. This finding may be because immunity offsets the high rate of febrile malaria that might otherwise result in stable hotspots, whereas unstable hotspots necessarily affect a population with less prior exposure to malaria.

Idro R, Marsh K, John CC, Newton CRJ. 2010. Cerebral malaria: mechanisms of brain injury and strategies for improved neurocognitive outcome. Pediatr Res, 68 (4), pp. 267-274. | Citations: 136 (Scopus) | Show Abstract | Read more

Cerebral malaria is the most severe neurological complication of infection with Plasmodium falciparum. With >575,000 cases annually, children in sub-Saharan Africa are the most affected. Surviving patients have an increased risk of neurological and cognitive deficits, behavioral difficulties, and epilepsy making cerebral malaria a leading cause of childhood neurodisability in the region. The pathogenesis of neurocognitive sequelae is poorly understood: coma develops through multiple mechanisms and there may be several mechanisms of brain injury. It is unclear how an intravascular parasite causes such brain injury. Understanding these mechanisms is important to develop appropriate neuroprotective interventions. This article examines possible mechanisms of brain injury in cerebral malaria, relating this to the pathogenesis of the disease, and explores prospects for improved neurocognitive outcome.

Mullei K, Mudhune S, Wafula J, Masamo E, English M, Goodman C, Lagarde M, Blaauw D. 2010. Attracting and retaining health workers in rural areas: investigating nurses' views on rural posts and policy interventions. BMC Health Serv Res, 10 Suppl 1 (Suppl 1), pp. S1. | Citations: 21 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Kenya has bold plans for scaling up priority interventions nationwide, but faces major human resource challenges, with a lack of skilled workers especially in the most disadvantaged rural areas. METHODS: We investigated reasons for poor recruitment and retention in rural areas and potential policy interventions through quantitative and qualitative data collection with nursing trainees. We interviewed 345 trainees from four purposively selected Medical Training Colleges (MTCs) (166 pre-service and 179 upgrading trainees with prior work experience). Each interviewee completed a self-administered questionnaire including likert scale responses to statements about rural areas and interventions, and focus group discussions (FGDs) were conducted at each MTC. RESULTS: Likert scale responses indicated mixed perceptions of both living and working in rural areas, with a range of positive, negative and indifferent views expressed on average across different statements. The analysis showed that attitudes to working in rural areas were significantly positively affected by being older, but negatively affected by being an upgrading student. Attitudes to living in rural areas were significantly positively affected by being a student at the MTC furthest from Nairobi. During FGDs trainees raised both positive and negative aspects of rural life. Positive aspects included lower costs of living and more autonomy at work. Negative issues included poor infrastructure, inadequate education facilities and opportunities, higher workloads, and inadequate supplies and supervision. Particular concern was expressed about working in communities dominated by other tribes, reflecting Kenya's recent election-related violence. Quantitative and qualitative data indicated that students believed several strategies could improve rural recruitment and retention, with particular emphasis on substantial rural allowances and the ability to choose their rural location. Other interventions highlighted included provision of decent housing, and more rapid career advancement. However, recently introduced short term contracts in named locations were not favoured due to their lack of pension plans and job security. CONCLUSIONS: This study identified a range of potential interventions to increase rural recruitment and retention, with those most favored by nursing students being additional rural allowances, and allowing choice of rural location. Greater investment is needed in information systems to evaluate the impact of such policies.

Omodeo-Salè F, Cortelezzi L, Vommaro Z, Scaccabarozzi D, Dondorp AM. 2010. Dysregulation of L-arginine metabolism and bioavailability associated to free plasma heme. Am J Physiol Cell Physiol, 299 (1), pp. C148-C154. | Citations: 29 (Scopus) | Show Abstract | Read more

Severe Plasmodium falciparum malaria is associated with hypoargininemia, which contributes to impaired systemic and pulmonary nitric oxide (NO) production and endothelial dysfunction. Since intravascular hemolysis is an intrinsic feature of severe malaria, we investigated whether and by which mechanisms free heme [Fe(III)-protoporphyrin IX (FP)] might contribute to the dysregulation of L-arginine (L-Arg) metabolism and bioavailability. Carrier systems "y+" [or cationic amino acid transporter (CAT)] and "y+L" transport L-Arg into red blood cells (RBC), where it is hydrolyzed to ornithine and urea by arginase (isoform I) or converted to NO* and citrulline by endothelial nitric oxide synthase (eNOS). Our results show a significant and dose-dependent impairment of L-Arg transport into RBC pretreated with FP, with a strong inhibition of the system carrier y+L. Despite the impaired L-Arg influx, higher amounts of L-Arg-derived urea are produced by RBC preexposed to FP caused by activation of RBC arginase I. This activation appeared not to be mediated by oxidative modifications of the enzyme. We conclude that L-Arg transport across RBC membrane is impaired and arginase-mediated L-Arg consumption enhanced by free heme. This could contribute to reduced NO production in severe malaria.

Dondorp AM, Yeung S, White L, Nguon C, Day NPJ, Socheat D, von Seidlein L. 2010. Artemisinin resistance: current status and scenarios for containment (vol 8, pg 272, 2010) NATURE REVIEWS MICROBIOLOGY, 8 (7), pp. 530-530. | Citations: 198 (Scopus) | Read more

Krudsood S, Tangpukdee N, Wilairatana P, Pothipak N, Duangdee C, Warrell DA, Looareesuwan S. 2010. Intravenous ibuprofen (IV-ibuprofen) controls fever effectively in adults with acute uncomplicated Plasmodium falciparum malaria but prolongs parasitemia. Am J Trop Med Hyg, 83 (1), pp. 51-55. | Citations: 12 (Web of Science Lite) | Show Abstract | Read more

Because some febrile patients are unable to swallow or retain oral antipyretic drugs, we carried out a double-blind, placebo-controlled trial in which intravenous ibuprofen (IV-ibuprofen) was given to adults hospitalized with fever associated with acute uncomplicated falciparum malaria treated with oral artesunate plus mefloquine. Thirty patients received IV-ibuprofen 400 mg and 30 received placebo every 6 hours for 72 hours. Reduction in the area above 37.0 degrees C versus time curve was significantly greater for IV-ibuprofen than for placebo during the first 72 hours after first administration. No patients developed severe malaria; parasite clearance was delayed in the patients whose fevers were controlled by IV-ibuprofen (median 37.3 hours versus 23.7 hours in the placebo group [P = 0.0024]). This difference did not appear to be clinically important Adverse events, none considered severe, occurred equally in both groups. IV-ibuprofen was effective and well tolerated in reducing fever in febrile inpatients with malaria.

Yeo TW, Lampah DA, Tjitra E, Piera K, Gitawati R, Kenangalem E, Price RN, Anstey NM. 2010. Greater endothelial activation, Weibel-Palade body release and host inflammatory response to Plasmodium vivax, compared with Plasmodium falciparum: a prospective study in Papua, Indonesia. J Infect Dis, 202 (1), pp. 109-112. | Citations: 36 (Scopus) | Show Abstract | Read more

Pathogenic mechanisms underlying vivax malaria are poorly understood, with few studies comparing endothelial and inflammatory responses with falciparum malaria. In adults with uncomplicated vivax or falciparum malaria, we compared plasma measurements of endothelial Weibel-Palade body release (angiopoietin-2) and activation (ICAM-1, E-selectin), as well as selected cytokines. Despite a lower median parasite count, angiopoietin-2 concentrations were higher in patients with vivax malaria, compared with falciparum malaria. Per peripheral parasite, median plasma angiopoietin-2, ICAM-1, E-selectin, interleukin-6, and interleukin-10 concentrations were higher in patients with malaria due to Plasmodium vivax. P. vivax induces greater endothelial Weibel-Palade body release and activation and greater host inflammatory responses, compared with Plasmodium falciparum.

Randall LM, Kenangalem E, Lampah DA, Tjitra E, Mwaikambo ED, Handojo T, Piera KA, Zhao ZZ, de Labastida Rivera F, Zhou Y et al. 2010. Age-related susceptibility to severe malaria associated with galectin-2 in highland Papuans. J Infect Dis, 202 (1), pp. 117-124. | Citations: 6 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Age and host genetics are important determinants of malaria severity. Lymphotoxin-alpha (LTalpha) has been associated with the development of cerebral malaria (CM) and other severe malaria (SM) syndromes. Mutations in genes regulating LTalpha production contribute to other acute vascular diseases and may contribute to malaria pathogenesis. METHODS: We tested the association between rs7291467, a single-nucleotide polymorphism (SNP) in the LTalpha-related gene encoding galectin-2 (LGALS2), disease severity, and function in a case-control study of ethnic Highland Papuan adults and children with SM (n = 380) and asymptomatic malaria-exposed controls (n = 356) originating from a non-malaria-endemic region but residing in a lowland malaria-endemic area of Papua, Indonesia. RESULTS: The LGALS2 SNP showed a significant association with susceptibility to SM (including CM), in children (odds ratio, 2.02 [95% confidence interval, 1.14-3.57]) but not in adults. In SM, the C allele at rs7291467 was associated with enhanced galectin-2 transcript levels. In a separate group of Tanzanian children originating from a malaria-endemic region, we found preservation of the major ancestral LGALS2 allele and no association with susceptibility to CM. CONCLUSIONS: Results suggest differences in the inflammatory contribution to the development of SM between children and adults in the same population and potential differences between individuals originating from malaria-endemic and non-malaria-endemic areas.

Thai KTD, Cazelles B, Nguyen NV, Vo LT, Boni MF, Farrar J, Simmons CP, van Doorn HR, de Vries PJ. 2010. Dengue dynamics in Binh Thuan province, southern Vietnam: periodicity, synchronicity and climate variability. PLoS Negl Trop Dis, 4 (7), pp. e747. | Citations: 54 (Scopus) | Show Abstract | Read more

BACKGROUND: Dengue is a major global public health problem with increasing incidence and geographic spread. The epidemiology is complex with long inter-epidemic intervals and endemic with seasonal fluctuations. This study was initiated to investigate dengue transmission dynamics in Binh Thuan province, southern Vietnam. METHODOLOGY: Wavelet analyses were performed on time series of monthly notified dengue cases from January 1994 to June 2009 (i) to detect and quantify dengue periodicity, (ii) to describe synchrony patterns in both time and space, (iii) to investigate the spatio-temporal waves and (iv) to associate the relationship between dengue incidence and El Niño-Southern Oscillation (ENSO) indices in Binh Thuan province, southern Vietnam. PRINCIPAL FINDINGS: We demonstrate a continuous annual mode of oscillation and a multi-annual cycle of around 2-3-years was solely observed from 1996-2001. Synchrony in time and between districts was detected for both the annual and 2-3-year cycle. Phase differences used to describe the spatio-temporal patterns suggested that the seasonal wave of infection was either synchronous among all districts or moving away from Phan Thiet district. The 2-3-year periodic wave was moving towards, rather than away from Phan Thiet district. A strong non-stationary association between ENSO indices and climate variables with dengue incidence in the 2-3-year periodic band was found. CONCLUSIONS: A multi-annual mode of oscillation was observed and these 2-3-year waves of infection probably started outside Binh Thuan province. Associations with climatic variables were observed with dengue incidence. Here, we have provided insight in dengue population transmission dynamics over the past 14.5 years. Further studies on an extensive time series dataset are needed to test the hypothesis that epidemics emanate from larger cities in southern Vietnam.

Sonthayanon P, Peacock SJ, Chierakul W, Wuthiekanun V, Blacksell SD, Holden MTG, Bentley SD, Feil EJ, Day NPJ. 2010. High rates of homologous recombination in the mite endosymbiont and opportunistic human pathogen Orientia tsutsugamushi. PLoS Negl Trop Dis, 4 (7), pp. e752. | Citations: 23 (Scopus) | Show Abstract | Read more

Orientia tsutsugamushi is an intracellular alpha-proteobacterium which resides in trombiculid mites, and is the causative agent of scrub typhus in East Asia. The genome sequence of this species has revealed an unprecedented number of repeat sequences, most notably of the genes encoding the conjugative properties of a type IV secretion system (T4SS). Although this observation is consistent with frequent intragenomic recombination, the extent of homologous recombination (gene conversion) in this species is unknown. To address this question, and to provide a protocol for the epidemiological surveillance of this important pathogen, we have developed a multilocus sequence typing (MLST) scheme based on 7 housekeeping genes (gpsA, mdh, nrdB, nuoF, ppdK, sucD, sucB). We applied this scheme to the two published genomes, and to DNA extracted from blood taken from 84 Thai scrub typhus patients, from 20 cultured Thai patient isolates, 1 Australian patient sample, and from 3 cultured type strains. These data demonstrated that the O. tsutsugamushi population was both highly diverse [Simpson's index (95% CI) = 0.95 (0.92-0.98)], and highly recombinogenic. These results are surprising given the intracellular life-style of this species, but are broadly consistent with results obtained for Wolbachia, which is an alpha-proteobacterial reproductive parasite of arthropods. We also compared the MLST data with ompA sequence data and noted low levels of consistency and much higher discrimination by MLST. Finally, twenty-five percent of patients in this study were simultaneously infected with multiple sequence types, suggesting multiple infection caused by either multiple mite bites, or multiple strains co-existing within individual mites.

Rabaa MA, Ty Hang VT, Wills B, Farrar J, Simmons CP, Holmes EC. 2010. Phylogeography of recently emerged DENV-2 in southern Viet Nam. PLoS Negl Trop Dis, 4 (7), pp. e766. | Citations: 43 (Scopus) | Show Abstract | Read more

Revealing the dispersal of dengue viruses (DENV) in time and space is central to understanding their epidemiology. However, the processes that shape DENV transmission patterns at the scale of local populations are not well understood, particularly the impact of such factors as human population movement and urbanization. Herein, we investigated trends in the spatial dynamics of DENV-2 transmission in the highly endemic setting of southern Viet Nam. Through a phylogeographic analysis of 168 full-length DENV-2 genome sequences obtained from hospitalized dengue cases from 10 provinces in southern Viet Nam, we reveal substantial genetic diversity in both urban and rural areas, with multiple lineages identified in individual provinces within a single season, and indicative of frequent viral migration among communities. Focusing on the recently introduced Asian I genotype, we observed particularly high rates of viral exchange between adjacent geographic areas, and between Ho Chi Minh City, the primary urban center of this region, and populations across southern Viet Nam. Within Ho Chi Minh City, patterns of DENV movement appear consistent with a gravity model of virus dispersal, with viruses traveling across a gradient of population density. Overall, our analysis suggests that Ho Chi Minh City may act as a source population for the dispersal of DENV across southern Viet Nam, and provides further evidence that urban areas of Southeast Asia play a primary role in DENV transmission. However, these data also indicate that more rural areas are also capable of maintaining virus populations and hence fueling DENV evolution over multiple seasons.

Preechapornkul P, Chotivanich K, Imwong M, Dondorp AM, Lee SJ, Day NPJ, White NJ, Pukrittayakamee S. 2010. Optimizing the culture of Plasmodium falciparum in hollow fiber bioreactors. Southeast Asian J Trop Med Public Health, 41 (4), pp. 761-769. | Citations: 7 (Scopus) | Show Abstract

The hollow fiber bioreactor (HFBR) is a cell culturing system allowing continuous perfusion of medium. It was designed to grow microorganisms in a dynamically altering medium mimicking change in the in vivo intravascular and extravascular compartments. The cell compartment (extra capillary space) and medium compartment (intra capillary space) are connected through pores of semipermeable fiber membranes. These membranes allow exchange of gas and nutrients. We have adapted this system for the ex vivo culture of Plasmodiumfalciparum at high parasite densities. A Thai P. falciparum isolate (TM036) cultured in RPMI, supplemented with 0.5% Albumax II, could be maintained continuously in the system by daily changes of a small volumes of medium. Under optimized conditions the HFBR cultures attained 8% parasitemia in 40% hematocrit, thereby providing a total parasite biomass of 6.0 x 10(9) parasitized erythrocytes. The main problem encountered was clogging of micropores in the hollow fiber system by cellular debris over time. Although 'reverse flushing' partly prevented this, a larger pore size might be needed to overcome this problem. The system opens new possibilities for the study of in vitro drug sensitivity under conditions mimicking in vivo pharmacokinetics, and the selection of anti-malarial drug resistance and associated parasite biological and genomic changes.

Chau TTH, Campbell JI, Schultsz C, Chau NVV, Diep TS, Baker S, Chinh NT, Farrar JJ, van Doorn HR. 2010. Three adult cases of Listeria monocytogenes meningitis in Vietnam. PLoS Med, 7 (7), pp. e1000306. | Citations: 6 (Scopus) | Read more

Ihekweazu C, Basarab M, Wilson D, Oliver I, Dance D, George R, Pebody R. 2010. Outbreaks of serious pneumococcal disease in closed settings in the post-antibiotic era: a systematic review. J Infect, 61 (1), pp. 21-27. | Citations: 14 (Scopus) | Show Abstract | Read more

SUMMARY OBJECTIVES: Since the introduction of antibiotics, pneumococcal disease is predominantly sporadic, with occasional outbreaks. Our objective was to review the epidemiology of reported outbreaks of serious pneumococcal disease in closed settings to inform the development of guidelines to manage such outbreaks. METHODS: We systematically reviewed the literature for reported outbreaks of serious pneumococcal disease in closed settings to inform the development of guidelines in managing such outbreaks. RESULTS: We identified 42 outbreaks reported in 39 papers---14 in hospitals, 12 in long term care facilities, five outbreaks in households, four in military settings, three in child care settings and two each in homeless shelters and jails. The serotype/group most frequently associated with outbreaks was 14 (seven outbreaks) followed by 4 (five outbreaks) then serotypes/groups 1, 9 and 9V each causing four outbreaks. The median outbreak size was four cases (2 - 46). The median duration was eight days, with 84% of cases occurring within 14 days of the first case. CONCLUSION: Outbreaks of serious pneumococcal disease are likely to continue happening requiring early recognition and implementation of public health measures in order to interrupt transmission. This study facilitated the development of the first UK interim guidelines for managing such outbreaks.

Ali M, Deen JL, Khatib A, Enwere G, von Seidlein L, Reyburn R, Ali SM, Chang NY, Perroud V, Marodon F et al. 2010. Paperless registration during survey enumerations and large oral cholera mass vaccination in Zanzibar, the United Republic of Tanzania. Bull World Health Organ, 88 (7), pp. 556-559. | Citations: 20 (Scopus) | Show Abstract | Read more

PROBLEM: Field trials require extensive data preparation and complex logistics. The use of personal digital assistants (PDAs) can bypass many of the traditional steps that are necessary in a paper-based data entry system. APPROACH: We programmed, designed and supervised the use of PDAs for a large survey enumeration and mass vaccination campaign. LOCAL SETTING: The project was implemented in Zanzibar in the United Republic of Tanzania. Zanzibar is composed of two main islands, Unguja and Pemba, where outbreaks of cholera have been reported since the 1970s. RELEVANT CHANGES: PDAs allowed us to digitize information at the initial point of contact with the respondents. Immediate response by the system in case of error helped ensure the quality and reliability of the data. PDAs provided quick data summaries that allowed subsequent research activities to be implemented in a timely fashion. LESSONS LEARNT: Portability, immediate recording and linking of information enhanced structure data collection in our study. PDAs could be more useful than paper-based systems for data collection in the field, especially in impoverished settings in developing countries.

Baaten GG, Roukens AH, Geskus RB, Kint JA, Coutinho RA, Sonder GJ, van den Hoek A. 2010. Symptoms of infectious diseases in travelers with diabetes mellitus: a prospective study with matched controls. J Travel Med, 17 (4), pp. 256-263. | Citations: 8 (Scopus) | Show Abstract | Read more

BACKGROUND: Travelers with diabetes mellitus to developing countries are thought to have symptomatic infectious diseases more often and longer than travelers without diabetes. Evidence for this is needed. This study evaluates whether travelers with diabetes are at increased risk of symptomatic infectious diseases. METHODS: A prospective study was performed between October 2003 and February 2008 among adult medication-dependent travelers with diabetes, with their healthy travel companions without diabetes serving as matched controls. Thus, travelers with diabetes and controls were assumed to have comparable exposure to infection. Data on symptoms of infectious diseases were recorded by using a structured diary. RESULTS: Among 70 travelers with insulin-dependent diabetes, the incidence of travel-related diarrhea was 0.99 per person-month, and the median number of symptomatic days 1.54 per month. For their 70 controls, figures were 0.74 and 1.57, respectively (p > 0.05). Among 82 travelers with non-insulin-dependent diabetes, incidence was 0.75, and the median number of symptomatic days was 1.68. For their 82 controls, figures were 0.70 and 1.68, respectively (p > 0.05). As for other symptoms, no significant travel-related differences were found. Only 17% of travelers with diabetes suffering from diarrhea used their stand-by antibiotics. CONCLUSIONS: Medication-dependent travelers with diabetes traveling to developing countries do not have symptomatic infectious diseases more often or longer than travelers without diabetes. Routine prescription of stand-by antibiotics for travelers with diabetes to areas with good health facilities is probably not more useful than for healthy travelers.

Ley B, Mtove G, Thriemer K, Amos B, von Seidlein L, Hendriksen I, Mwambuli A, Shoo A, Malahiyo R, Ame SM et al. 2010. Evaluation of the Widal tube agglutination test for the diagnosis of typhoid fever among children admitted to a rural hdospital in Tanzania and a comparison with previous studies. BMC Infect Dis, 10 (1), pp. 180. | Citations: 19 (Scopus) | Show Abstract | Read more

BACKGROUND: The diagnosis of typhoid fever is confirmed by culture of Salmonella enterica serotype Typhi (S. typhi). However, a more rapid, simpler, and cheaper diagnostic method would be very useful especially in developing countries. The Widal test is widely used in Africa but little information exists about its reliability. METHODS: We assessed the performance of the Widal tube agglutination test among febrile hospitalized Tanzanian children. We calculated the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of various anti-TH and -TO titers using culture-confirmed typhoid fever cases as the "true positives" and all other febrile children with blood culture negative for S. typhi as the "true negatives." RESULTS: We found that 16 (1%) of 1,680 children had culture-proven typhoid fever. A single anti-TH titer of 1:80 and higher was the optimal indicator of typhoid fever. This had a sensitivity of 75%, specificity of 98%, NPV of 100%, but PPV was only 26%. We compared our main findings with those from previous studies. CONCLUSION: Among febrile hospitalized Tanzanian children with a low prevalence of typhoid fever, a Widal titer of > or = 1:80 performed well in terms of sensitivity, specificity, and NPV. However a test with improved PPV that is similarly easy to apply and cost-efficient is desirable.

Jokinen J, Scott JAG. 2010. Estimating the proportion of pneumonia attributable to pneumococcus in Kenyan adults: latent class analysis. Epidemiology, 21 (5), pp. 719-725. | Citations: 17 (Scopus) | Show Abstract | Read more

BACKGROUND: Community-acquired pneumonia is a common cause of hospitalization among African adults, and Streptococcus pneumoniae is assumed to be a frequent cause. Pneumococcal conjugate vaccine is currently being introduced into childhood immunization programs in Africa. The case for adult vaccination is dependent on the contribution of the pneumococcus to the hospital pneumonia burden. METHODS: Pneumococcal diagnosis is complex because there is no gold standard, and culture methods are invalidated by antibiotic use. We used latent class analysis to estimate the proportion of pneumonia episodes caused by pneumococcus. Furthermore, we extended this methodology to evaluate the effect of antimicrobial treatment on test accuracies and the prevalence of the disease. The study combined data from 5 validation studies of pneumococcal diagnostic tests performed on 281 Kenyan adults with pneumonia. RESULTS: The proportion of pneumonia episodes attributable to pneumococcus was 0.46 (95% confidence interval = 0.36-0.57). Failure to account for the effect of antimicrobial exposure underestimates this proportion as 0.32. A history of antibiotic exposure was a poor predictor of antimicrobial activity in patients' urine. Blood culture sensitivity for pneumococcus was estimated at 0.24 among patients with antibiotic exposure, and 0.75 among those without. CONCLUSIONS: The large contribution of pneumococcus to adult pneumonia provides a strong case for the investigation of pneumococcal vaccines in African adults.

Hay SI, Okiro EA, Gething PW, Patil AP, Tatem AJ, Guerra CA, Snow RW. 2010. Estimating the global clinical burden of Plasmodium falciparum malaria in 2007. PLoS Med, 7 (6), pp. e1000290. | Citations: 225 (Scopus) | Show Abstract | Read more

BACKGROUND: The epidemiology of malaria makes surveillance-based methods of estimating its disease burden problematic. Cartographic approaches have provided alternative malaria burden estimates, but there remains widespread misunderstanding about their derivation and fidelity. The aims of this study are to present a new cartographic technique and its application for deriving global clinical burden estimates of Plasmodium falciparum malaria for 2007, and to compare these estimates and their likely precision with those derived under existing surveillance-based approaches. METHODS AND FINDINGS: In seven of the 87 countries endemic for P. falciparum malaria, the health reporting infrastructure was deemed sufficiently rigorous for case reports to be used verbatim. In the remaining countries, the mapped extent of unstable and stable P. falciparum malaria transmission was first determined. Estimates of the plausible incidence range of clinical cases were then calculated within the spatial limits of unstable transmission. A modelled relationship between clinical incidence and prevalence was used, together with new maps of P. falciparum malaria endemicity, to estimate incidence in areas of stable transmission, and geostatistical joint simulation was used to quantify uncertainty in these estimates at national, regional, and global scales. Combining these estimates for all areas of transmission risk resulted in 451 million (95% credible interval 349-552 million) clinical cases of P. falciparum malaria in 2007. Almost all of this burden of morbidity occurred in areas of stable transmission. More than half of all estimated P. falciparum clinical cases and associated uncertainty occurred in India, Nigeria, the Democratic Republic of the Congo (DRC), and Myanmar (Burma), where 1.405 billion people are at risk. Recent surveillance-based methods of burden estimation were then reviewed and discrepancies in national estimates explored. When these cartographically derived national estimates were ranked according to their relative uncertainty and replaced by surveillance-based estimates in the least certain half, 98% of the global clinical burden continued to be estimated by cartographic techniques. CONCLUSIONS AND SIGNIFICANCE: Cartographic approaches to burden estimation provide a globally consistent measure of malaria morbidity of known fidelity, and they represent the only plausible method in those malaria-endemic countries with nonfunctional national surveillance. Unacceptable uncertainty in the clinical burden of malaria in only four countries confounds our ability to evaluate needs and monitor progress toward international targets for malaria control at the global scale. National prevalence surveys in each nation would reduce this uncertainty profoundly. Opportunities for further reducing uncertainty in clinical burden estimates by hybridizing alternative burden estimation procedures are also evaluated.

Habib AG, Nasidi A, Alder N, Juszczak E, David R, Theakston G, Warrell DA, UK ESGN. 2010. Response to a letter from J-P Chippaux and L Boyer entitled: "The 3+3 dose escalation design is not appropriate for antivenom dose finding." TOXICON, 55 (7), pp. 1410-1411. | Citations: 1 (Web of Science Lite) | Read more

Halling-Brown M, Pappalardo F, Rapin N, Zhang P, Alemani D, Emerson A, Castiglione F, Duroux P, Pennisi M, Miotto O et al. 2010. ImmunoGrid: towards agent-based simulations of the human immune system at a natural scale. Philos Trans A Math Phys Eng Sci, 368 (1920), pp. 2799-2815. | Citations: 27 (Scopus) | Show Abstract | Read more

The ultimate aim of the EU-funded ImmunoGrid project is to develop a natural-scale model of the human immune system-that is, one that reflects both the diversity and the relative proportions of the molecules and cells that comprise it-together with the grid infrastructure necessary to apply this model to specific applications in the field of immunology. These objectives present the ImmunoGrid Consortium with formidable challenges in terms of complexity of the immune system, our partial understanding about how the immune system works, the lack of reliable data and the scale of computational resources required. In this paper, we explain the key challenges and the approaches adopted to overcome them. We also consider wider implications for the present ambitious plans to develop natural-scale, integrated models of the human body that can make contributions to personalized health care, such as the European Virtual Physiological Human initiative. Finally, we ask a key question: How long will it take us to resolve these challenges and when can we expect to have fully functional models that will deliver health-care benefits in the form of personalized care solutions and improved disease prevention?

Mabotuwana T, Warren J, Elley CR, Kennelly J, Paton C, Warren D, Chang Wai K, Wells S. 2010. Use of interval based quality indicators in blood pressure management to enhance quality of pay for performance incentives: comparison to two indicators from the Quality and Outcomes Framework. Qual Prim Care, 18 (2), pp. 93-101. | Citations: 6 (Scopus) | Show Abstract

BACKGROUND: Pay for performance incentives are becoming increasingly popular, but are typically based on only a single point-in-time measurement as an indicator of chronic condition management. AIMS: To determine the association between three time-interval based indicators of suboptimal blood pressure (BP) control and two point-in-time indicators from the UK Quality and Outcomes Framework (QOF): BP5 (the percentage of patients with hypertension in whom the last BP in the previous nine months was < or = 150/90) and DM12 (the percentage of patients with diabetes in whom the last BP in the previous 15 months was < or = 145/85). METHODS: We extracted classification data and BP measurements from four New Zealand general practices with 4260 to 6130 enrolled patients. Data were analysed for three indicators with respect to a nine-month evaluation period for patients with hypertension and a 15-month period for patients with diabetes: (1) two or more consistently high BP measurements spaced over > or = 90 days, (2) a high BP measurement followed by a lapse of >120 days in BP measurement and (3) no BP measurement for >180 days. RESULTS: For the four practices, 65-81% of the patients satisfied BP5 and 59-68% of patients satisfied DM12. Of the hypertension patients satisfying BP5, 31% (95% CI: 28-33%) failed at least one of the three interval based indicators; 42% (95% CI: 39-46%) of the diabetes patients satisfying DM12 failed at least one of the three interval based indicators. CONCLUSION: Considering only a point-in-time controlled BP measurement provides an incomplete view of the quality of BP management in patients with hypertension or diabetes over a period of time.

McAuley CF, Webb C, Makani J, Macharia A, Uyoga S, Opi DH, Ndila C, Ngatia A, Scott JAG, Marsh K, Williams TN. 2010. High mortality from Plasmodium falciparum malaria in children living with sickle cell anemia on the coast of Kenya. Blood, 116 (10), pp. 1663-1668. | Citations: 49 (Scopus) | Show Abstract | Read more

Although malaria is widely considered a major cause of death in young children born with sickle cell anemia (SCA) in sub-Saharan Africa, this is poorly quantified. We attempted to investigate this question through 4 large case-control analyses involving 7164 children living on the coast of Kenya. SCA was associated with an increased risk of admission to hospital both with nonmalaria diseases in general (odds ratio [OR] = 4.17; 95% confidence interval [CI], 1.95-8.92; P < .001) and with invasive bacterial diseases in particular (OR = 8.73; 95% CI, 4.51-16.89; P < .001). We found no evidence for a strongly increased risk of either uncomplicated malaria (OR = 0.43; 95% CI, 0.09-2.10; P = .30) or malaria complicated by a range of well-described clinical features of severity (OR = 0.80; 95% CI, 0.25-2.51; P = .70) overall; nevertheless, mortality was considerably higher among SCA than non-SCA children hospitalized with malaria. Our findings highlight both the central role that malaria plays in the high early mortality seen in African children with SCA and the urgent need for better quantitative data. Meanwhile, our study confirms the importance of providing all children living with SCA in malaria-endemic areas with effective prophylaxis.

Khor CC, Vannberg FO, Chapman SJ, Guo H, Wong SH, Walley AJ, Vukcevic D, Rautanen A, Mills TC, Chang K-C et al. 2010. CISH and susceptibility to infectious diseases. N Engl J Med, 362 (22), pp. 2092-2101. | Citations: 72 (Scopus) | Show Abstract | Read more

BACKGROUND: The interleukin-2-mediated immune response is critical for host defense against infectious pathogens. Cytokine-inducible SRC homology 2 (SH2) domain protein (CISH), a suppressor of cytokine signaling, controls interleukin-2 signaling. METHODS: Using a case-control design, we tested for an association between CISH polymorphisms and susceptibility to major infectious diseases (bacteremia, tuberculosis, and severe malaria) in blood samples from 8402 persons in Gambia, Hong Kong, Kenya, Malawi, and Vietnam. We had previously tested 20 other immune-related genes in one or more of these sample collections. RESULTS: We observed associations between variant alleles of multiple CISH polymorphisms and increased susceptibility to each infectious disease in each of the study populations. When all five single-nucleotide polymorphisms (SNPs) (at positions -639, -292, -163, +1320, and +3415 [all relative to CISH]) within the CISH-associated locus were considered together in a multiple-SNP score, we found an association between CISH genetic variants and susceptibility to bacteremia, malaria, and tuberculosis (P=3.8x10(-11) for all comparisons), with -292 accounting for most of the association signal (P=4.58x10(-7)). Peripheral-blood mononuclear cells obtained from adult subjects carrying the -292 variant, as compared with wild-type cells, showed a muted response to the stimulation of interleukin-2 production--that is, 25 to 40% less CISH expression. CONCLUSIONS: Variants of CISH are associated with susceptibility to diseases caused by diverse infectious pathogens, suggesting that negative regulators of cytokine signaling have a role in immunity against various infectious diseases. The overall risk of one of these infectious diseases was increased by at least 18% among persons carrying the variant CISH alleles.

Kim HG, Hien TT, Han EH, Chung YC, Jeong HG. 2010. Molecular mechanism of endothelial nitric-oxide synthase activation by Platycodon grandiflorum root-derived saponins. Toxicol Lett, 195 (2-3), pp. 106-113. | Citations: 8 (Scopus) | Show Abstract | Read more

Nitric oxide (NO) produced by endothelial nitric-oxide synthase (eNOS) has antithrombotic and antiatherosclerotic properties in the vasculature. Previously, we demonstrated that saponins derived from the roots of Platycodon grandiflorum (CKS) inhibited the tumor necrosis factor-alpha-induced expression of adhesion molecules in human endothelial cells. In this study, we found that CKS increased eNOS phosphorylation and NO production in human endothelial cells. Treatment with CKS increased the phosphorylation of Akt, p38/MAPK, AMP-activated protein kinase (AMPK), and calmodulin-dependent protein kinase II (CaMK II) leading to increased NO production in human endothelial cells. Moreover, inhibitors of Akt (LY294002), p38/MAPK (SB203580), AMPK (compound C), and CaMK II (W7) failed to suppress CKS-induced eNOS phosphorylation. In addition, CKS-induced eNOS phosphorylation was inhibited by the overexpression of a dominant-negative mutant form of AMPK (DN-AMPK). Taken together, these results indicate that CKS stimulates eNOS phosphorylation and NO production via the activation of PI3K/Akt, p38/MAPK, AMPK, and CaMK II.

Douglas NM, Anstey NM, Angus BJ, Nosten F, Price RN. 2010. Artemisinin combination therapy for vivax malaria. Lancet Infect Dis, 10 (6), pp. 405-416. | Citations: 142 (Scopus) | Show Abstract | Read more

Early parasitological diagnosis and treatment with artemisinin-based combination therapies (ACTs) are key components of worldwide malaria elimination programmes. In general, use of ACTs has been limited to patients with falciparum malaria whereas blood-stage infections with Plasmodium vivax are mostly still treated with chloroquine. We review the evidence for the relative benefits and disadvantages of the existing separate treatment approach versus a unified ACT-based strategy for treating Plasmodium falciparum and P vivax infections in regions where both species are endemic (co-endemic). The separate treatment scenario is justifiable if P vivax remains sensitive to chloroquine and diagnostic tests reliably distinguish P vivax from P falciparum. However, with the high number of misdiagnoses in routine practice and the rise and spread of chloroquine-resistant P vivax, there might be a compelling rationale for a unified ACT-based strategy for vivax and falciparum malaria in all co-endemic regions. Analyses of the cost-effectiveness of ACTs for both Plasmodium species are needed to assess the role of these drugs in the control and elimination of vivax malaria.

Pagnarith Y, Kumar V, Thaipadungpanit J, Wuthiekanun V, Amornchai P, Sin L, Day NP, Peacock SJ. 2010. Emergence of pediatric melioidosis in Siem Reap, Cambodia. Am J Trop Med Hyg, 82 (6), pp. 1106-1112. | Citations: 34 (Scopus) | Show Abstract | Read more

We describe the first cases of pediatric melioidosis in Cambodia. Thirty-nine cases were diagnosed at the Angkor Hospital for Children, Siem Reap, between October 2005 and December 2008 after the introduction of microbiology capabilities. Median age was 7.8 years (range = 1.6-16.2 years), 15 cases were male (38%), and 4 cases had pre-existing conditions that may have pre-disposed the patient to melioidosis. Infection was localized in 27 cases (69%) and disseminated in 12 cases (31%). Eleven cases (28%) were treated as outpatients, and 28 (72%) cases were admitted. Eight children (21%) died a median of 2 days after admission; seven deaths were attributable to melioidosis, all of which occurred in children receiving suboptimal antimicrobial therapy and before bacteriological culture results were available. Our findings indicate the need for heightened awareness of melioidosis in Cambodia, and they have led us to review microbiology procedures and antimicrobial prescribing of suspected and confirmed cases.

Limmathurotsakul D, Wongratanacheewin S, Teerawattanasook N, Wongsuvan G, Chaisuksant S, Chetchotisakd P, Chaowagul W, Day NPJ, Peacock SJ. 2010. Increasing incidence of human melioidosis in Northeast Thailand. Am J Trop Med Hyg, 82 (6), pp. 1113-1117. | Citations: 205 (Scopus) | Show Abstract | Read more

Melioidosis is a serious community-acquired infectious disease caused by the Gram-negative environmental bacterium Burkholderia pseudomallei. A prospective cohort study identified 2,243 patients admitted to Sappasithiprasong Hospital in northeast Thailand with culture-confirmed melioidosis between 1997 and 2006. These data were used to calculate an average incidence rate for the province of 12.7 cases of melioidosis per 100,000 people per year. Incidence increased incrementally from 8.0 (95% confidence interval [CI] = 7.2-10.0) in 2000 to 21.3 (95% CI = 19.2-23.6) in 2006 (P < 0.001; chi(2) test for trend). Male sex, age >/= 45 years, and either known or undiagnosed diabetes were independent risk factors for melioidosis. The average mortality rate from melioidosis over the study period was 42.6%. The minimum estimated population mortality rate from melioidosis in 2006 was 8.63 per 100,000 people (95% CI = 7.33-10.11), the third most common cause of death from infectious diseases in northeast Thailand after human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) and tuberculosis.

McGready R. 2010. Intermittent preventive treatment of infants with mefloquine reduces risk of clinical malaria in areas of moderate malaria transmission and high resistance to sulphadoxine-pyrimethamine, but safety and tolerability issues need consideration. Evid Based Med, 15 (3), pp. 71-72. | Citations: 3 (Scopus) | Read more

Calvete JJ, Cid P, Sanz L, Segura A, Villalta M, Herrera M, León G, Harrison R, Durfa N, Nasidi A et al. 2010. Antivenomic assessment of the immunological reactivity of EchiTAb-Plus-ICP, an antivenom for the treatment of snakebite envenoming in sub-Saharan Africa. Am J Trop Med Hyg, 82 (6), pp. 1194-1201. | Citations: 30 (Scopus) | Show Abstract | Read more

The immunoreactivity of EchiTAb-Plus-ICP, an antivenom developed for the treatment of snakebite envenoming in sub-Saharan Africa, to venoms of seven Echis and Bitis species, was assessed by "antivenomics." This proteomic approach is based on the ability of an antivenom to immunodeplete homologous or heterologous venom proteins. Our results show an extensive cross-reactivity of this antivenom against all Echis and Bitis venoms studied, as revealed by the complete immunodepletion of the majority of venom components, including metalloproteinases, serine proteinases, C-type lectin-like proteins, some phospholipases A(2) and L-amino acid oxidase. However, some phospholipases A(2), disintegrins and proteinase inhibitors were immunodepleted to only a partial extent. These results support the hypothesis that immunizing horses with a mixture of the venoms of Echis ocellatus, Bitis arietans, and Naja nigricollis generates antibodies capable of recognizing the majority of components of medically-relevant homologous and heterologous viperid venoms of the genera Bitis and Echis from sub-Saharan Africa.

Karlson-Stiber CBM, Persson HE, Warrell DA. 2010. Use of antivenom in Vipera berus Bites--a comment. Wilderness Environ Med, 21 (2), pp. 180. | Citations: 1 (Scopus) | Read more

Limmathurotsakul D, Wuthiekanun V, Chantratita N, Wongsuvan G, Amornchai P, Day NPJ, Peacock SJ. 2010. Burkholderia pseudomallei is spatially distributed in soil in northeast Thailand. PLoS Negl Trop Dis, 4 (6), pp. e694. | Citations: 26 (Scopus) | Show Abstract | Read more

BACKGROUND: Melioidosis is a frequently fatal infectious disease caused by the soil dwelling Gram-negative bacterium Burkholderia pseudomallei. Environmental sampling is important to identify geographical distribution of the organism and related risk of infection to humans and livestock. The aim of this study was to evaluate spatial distribution of B. pseudomallei in soil and consider the implications of this for soil sampling strategies. METHODS AND FINDINGS: A fixed-interval sampling strategy was used as the basis for detection and quantitation by culture of B. pseudomallei in soil in two environmental sites (disused land covered with low-lying scrub and rice field) in northeast Thailand. Semivariogram and indicator semivariogram were used to evaluate the distribution of B. pseudomallei and its relationship with range between sampling points. B. pseudomallei was present on culture of 80/100 sampling points taken from the disused land and 28/100 sampling points from the rice field. The median B. pseudomallei cfu/gram from positive sampling points was 378 and 700 for the disused land and the rice field, respectively (p = 0.17). Spatial autocorrelation of B. pseudomallei was present, in that samples taken from areas adjacent to sampling points that were culture positive (negative) for B. pseudomallei were also likely to be culture positive (negative), and samples taken from areas adjacent to sampling points with a high (low) B. pseudomallei count were also likely to yield a high (low) count. Ranges of spatial autocorrelation in quantitative B. pseudomallei count were 11.4 meters in the disused land and 7.6 meters in the rice field. CONCLUSIONS: We discuss the implications of the uneven distribution of B. pseudomallei in soil for future environmental studies, and describe a range of established geostatistical sampling approaches that would be suitable for the study of B. pseudomallei that take account of our findings.

Nguyen NTK, Ha V, Tran NVT, Stabler R, Pham DT, Le TMV, van Doorn HR, Cerdeño-Tárraga A, Thomson N, Campbell J et al. 2010. The sudden dominance of blaCTX-M harbouring plasmids in Shigella spp. Circulating in Southern Vietnam. PLoS Negl Trop Dis, 4 (6), pp. e702. | Citations: 32 (Scopus) | Show Abstract | Read more

BACKGROUND: Plasmid mediated antimicrobial resistance in the Enterobacteriaceae is a global problem. The rise of CTX-M class extended spectrum beta lactamases (ESBLs) has been well documented in industrialized countries. Vietnam is representative of a typical transitional middle income country where the spectrum of infectious diseases combined with the spread of drug resistance is shifting and bringing new healthcare challenges. METHODOLOGY: We collected hospital admission data from the pediatric population attending the hospital for tropical diseases in Ho Chi Minh City with Shigella infections. Organisms were cultured from all enrolled patients and subjected to antimicrobial susceptibility testing. Those that were ESBL positive were subjected to further investigation. These investigations included PCR amplification for common ESBL genes, plasmid investigation, conjugation, microarray hybridization and DNA sequencing of a bla(CTX-M) encoding plasmid. PRINCIPAL FINDINGS: We show that two different bla(CTX-M) genes are circulating in this bacterial population in this location. Sequence of one of the ESBL plasmids shows that rather than the gene being integrated into a preexisting MDR plasmid, the bla(CTX-M) gene is located on relatively simple conjugative plasmid. The sequenced plasmid (pEG356) carried the bla(CTX-M-24) gene on an ISEcp1 element and demonstrated considerable sequence homology with other IncFI plasmids. SIGNIFICANCE: The rapid dissemination, spread of antimicrobial resistance and changing population of Shigella spp. concurrent with economic growth are pertinent to many other countries undergoing similar development. Third generation cephalosporins are commonly used empiric antibiotics in Ho Chi Minh City. We recommend that these agents should not be considered for therapy of dysentery in this setting.

Dau B, Ayers D, Singer J, Harrigan PR, Brown S, Kyriakides T, Cameron DW, Angus B, Holodniy M. 2010. Connection domain mutations in treatment-experienced patients in the OPTIMA trial. J Acquir Immune Defic Syndr, 54 (2), pp. 160-166. | Citations: 15 (Scopus) | Show Abstract | Read more

OBJECTIVES: To determine the frequency of mutations in the connection domain (CD) of HIV reverse transcriptase in treatment-experienced patients in the Options in Management with Antiretrovirals trial, their impact on susceptibility to antiretroviral (ARV) drugs, and their impact on virologic outcomes. METHODS: Baseline plasma ARV genotypes and inferred resistance phenotypes were obtained. Frequencies of E312Q, Y318F, G333D, G333E, G335C, G335D, N348I, A360I, A360V, V365I, A371V, A376S, and E399G were compared with a treatment-naive population. The association of CD mutations with inferred IC50 fold changes to nucleos(t)ide reverse transcriptase inhibitors was evaluated. Univariate and multivariate analyses examined the association of CD mutations with a >1 log10 per milliliter decrease in HIV viral load after 24 weeks on a new ARV regimen. RESULTS: Higher CD mutation rates were seen in Options in Management with Antiretrovirals patients (n = 345) compared with a treatment-naive population. CD mutations were associated with increased inferred IC50 fold changes to abacavir, stavudine, tenofovir, and zidovudine. On univariate analysis, A371V was associated with lack of virologic response, as was having any CD mutation on multivariate analysis. CONCLUSIONS: CD mutations are frequent in treatment-experienced populations. They are associated with reduced susceptibility to some nucleos(t)ide reverse transcriptase inhibitors and with a diminished response to ARV therapy.

Maguire JD, Baird JK. 2010. The 'non-falciparum' malarias: the roles of epidemiology, parasite biology, clinical syndromes, complications and diagnostic rigour in guiding therapeutic strategies. Ann Trop Med Parasitol, 104 (4), pp. 283-301. | Citations: 14 (Web of Science Lite) | Show Abstract | Read more

Plasmodium vivax, P. ovale, P. malariae and P. falciparum routinely infect humans. The infections caused by these parasites are loosely referred to as vivax (or benign tertian), ovale, malariae (or quartan) and falciparum (or malignant tertian) malaria, respectively. Recently, P. knowlesi, a parasite of macaque monkeys in South-east Asia, has been identified as the cause of uncomplicated and severe human malaria in Malaysian Borneo. The prescription of appropriate therapies for reliably diagnosed malaria requires a grasp of the epidemiology of the 'non-falciparum' malarias, the biology of the parasites involved, the chemotherapeutic strategies that are available and the problems of emerging drug resistance and changing clinical syndromes. This review is intended to increase clinicians' understanding of how these factors relate to the selection of the antimalarial drugs to be given to a case of 'non-falciparum' malaria, with the aims of improving outcomes and preventing relapses and recrudescences.

Jones KDJ, Berkley JA, Warner JO. 2010. Perinatal nutrition and immunity to infection. Pediatr Allergy Immunol, 21 (4 Pt 1), pp. 564-576. | Citations: 27 (Scopus) | Show Abstract | Read more

Epidemiological data provide strong evidence for a relationship between undernutrition and life-threatening infection in infants and children. However, the mechanisms that underlie this relationship are poorly understood. Through foetal life, infancy and childhood, the immune system undergoes a process of functional maturation. The adequacy of this process is dependent on environmental factors, and there is accumulating evidence of the impact of pre- and post-natal nutrition in this regard. This review outlines the impact of nutrition during foetal and infant development on the capacity to mount immune responses to infection. It provides an overview of the epidemiologic evidence for such a role and discusses the possible mechanisms involved.

Thuo N, Ohuma E, Karisa J, Talbert A, Berkley JA, Maitland K. 2010. The prognostic value of dipstick urinalysis in children admitted to hospital with severe malnutrition. Arch Dis Child, 95 (6), pp. 422-426. | Citations: 7 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Children with severe malnutrition (SAM) present to hospital with an array of complications, resulting in high mortality despite adherence to WHO guidelines. Diagnostic resources in developing countries are limited and bedside tests could help identify high-risk children. Dipstick urinalysis is a bedside screening test for urinary tract infections (UTIs). UTIs are common in SAM and can lead to secondary invasive bacterial sepsis. Very few studies have examined the usefulness of dipstick screening of urine specimens in SAM and none has explored its prognostic value. PATIENTS AND METHODS: A 2-year prospective study on children admitted in Kilifi District Hospital, Kenya, with SAM. Freshly voided, clean catch urine samples were tested using Multistix reagent test strips. Positive samples were sent for culture. RESULTS: Of the 667 children admitted, 498 children (75%) provided urine samples; of these, 119 (24%) were positive for either leucocyte esterase (LE) or nitrites. Culture-proven UTI was detected in 28 children (6% overall). All isolates were coliforms and were >50% were resistant to cotrimoxazole and gentamicin. There was no difference in severity signs between those with positive dipstick and those without. Case fatality was higher among children with a positive dipstick (29% vs 12%). Presence of a positive dipstick was a strong predictor of mortality (adjusted HR 2.5). CONCLUSIONS: A urine dipstick positive for either LE or nitrites is a useful predictor of death in children admitted with SAM. Prospective studies to determine the role of untreated UTI in these deaths are needed before any treatment recommendations can be made.

Youssef RM, Alegana VA, Amran J, Noor AM, Snow RW. 2010. Fever prevalence and management among three rural communities in the North West Zone, Somalia. East Mediterr Health J, 16 (6), pp. 595-601. | Citations: 2 (Scopus) | Show Abstract

Between March and August 2008 we undertook 2 cross-sectional surveys among 1375 residents of 3 randomly selected villages in the district of Gebiley in the North-West Zone, Somalia. We investigated for the presence of malaria infection and the period prevalence of self-reported fever 14 days prior to both surveys. All blood samples examined were negative for both species of Plasmodium. The period prevalence of 14-day fevers was 4.8% in March and 0.6% in August; the majority of fevers (84.4%) were associated with other symptoms including cough, running nose and sore throat; 48/64 cases had resolved by the day of interview (mean duration 5.4 days). Only 18 (37.5%) fever cases were managed at a formal health care facility: 7 within 24 hours and 10 within 24-72 hours of onset. None of the fevers were investigated for malaria; they were treated with antibiotics, antipyretics and vitamins.

Glover SJ, Maude RJ, Taylor TE, Molyneux ME, Beare NAV. 2010. Malarial retinopathy and fluorescein angiography findings in a Malawian child with cerebral malaria. Lancet Infect Dis, 10 (6), pp. 440. | Citations: 4 (Web of Science Lite) | Read more

Dondorp AM, Yeung S, White L, Nguon C, Day NPJ, Socheat D, Von Seidlein L. 2010. Erratum: Artemisinin resistance: Current status and scenarios for containment (Nature Reviews Microbiology (2010) 8 (272-280)) Nature Reviews Microbiology, 8 (7), pp. 530. | Citations: 3 (Scopus)

Subedi BH, Pokharel J, Thapa R, Banskota N, Basnyat B. 2010. Frostbite in a Sherpa. Wilderness Environ Med, 21 (2), pp. 127-129. | Citations: 3 (Scopus) | Show Abstract | Read more

Frostbite is frequently seen in high altitude climbers. Many Sherpas, members of an ethnic community living high in the Himalayas in Nepal, help the climbers as a guide or an assistant. They often seem to undertake few precautionary measures thus suffer more from frostbite. A young Sherpa, who had reached the top of Mt Kanchenjunga in March 2009, suffered from deep frostbite in his fingers. Fortunately, he recovered well with generous treatment. Though there is no evidence whether Sherpas are more or less prone to frostbite, simple techniques for adequate prevention of hypoxia, hypothermia and dehydration will benefit any climber to the high altitudes.

Holt KE, Baker S, Dongol S, Basnyat B, Adhikari N, Thorson S, Pulickal AS, Song Y, Parkhill J, Farrar JJ et al. 2010. High-throughput bacterial SNP typing identifies distinct clusters of Salmonella Typhi causing typhoid in Nepalese children. BMC Infect Dis, 10 (1), pp. 144. | Citations: 47 (Scopus) | Show Abstract | Read more

BACKGROUND: Salmonella Typhi (S. Typhi) causes typhoid fever, which remains an important public health issue in many developing countries. Kathmandu, the capital of Nepal, is an area of high incidence and the pediatric population appears to be at high risk of exposure and infection. METHODS: We recently defined the population structure of S. Typhi, using new sequencing technologies to identify nearly 2,000 single nucleotide polymorphisms (SNPs) that can be used as unequivocal phylogenetic markers. Here we have used the GoldenGate (Illumina) platform to simultaneously type 1,500 of these SNPs in 62 S. Typhi isolates causing severe typhoid in children admitted to Patan Hospital in Kathmandu. RESULTS: Eight distinct S. Typhi haplotypes were identified during the 20-month study period, with 68% of isolates belonging to a subclone of the previously defined H58 S. Typhi. This subclone was closely associated with resistance to nalidixic acid, with all isolates from this group demonstrating a resistant phenotype and harbouring the same resistance-associated SNP in GyrA (Phe83). A secondary clone, comprising 19% of isolates, was observed only during the second half of the study. CONCLUSIONS: Our data demonstrate the utility of SNP typing for monitoring bacterial populations over a defined period in a single endemic setting. We provide evidence for genotype introduction and define a nalidixic acid resistant subclone of S. Typhi, which appears to be the dominant cause of severe pediatric typhoid in Kathmandu during the study period.

Niederer HA, Willcocks LC, Rayner TF, Yang W, Lau YL, Williams TN, Scott JAG, Urban BC, Peshu N, Dunstan SJ et al. 2010. Copy number, linkage disequilibrium and disease association in the FCGR locus. Hum Mol Genet, 19 (16), pp. 3282-3294. | Citations: 86 (Scopus) | Show Abstract | Read more

The response of a leukocyte to immune complexes (ICs) is modulated by receptors for the Fc region of IgG (FcgammaRs), and alterations in their affinity or function have been associated with risk of autoimmune diseases, including systemic lupus erythematosus (SLE). The low-affinity FcgammaR genomic locus is complex, containing regions of copy number variation (CNV) which can alter receptor expression and leukocyte responses to IgG. Combined paralogue ratio tests (PRTs) were used to distinguish three intervals within the FCGR locus which undergo CNV, and to determine FCGR gene copy number (CN). There were significant differences in FCGR3B and FCGR3A CNV profiles between Caucasian, East Asian and Kenyan populations. A previously noted association of low FCGR3B CN with SLE in Caucasians was supported [OR = 1.57 (1.08-2.27), P = 0.018], and replicated in Chinese [OR = 1.65 (1.25-2.18), P = 4 x 10(-4)]. There was no association of FCGR3B CNV with vasculitis, nor with malarial or bacterial infection. Linkage disequilibrium (LD) between multi-allelic FCGR3B CNV and SLE-associated SNPs in the FCGR locus was defined for the first time. Despite LD between FCGR3B CNV and a variant in FcgammaRIIB (I232T) which abolishes inhibitory function, both reduced CN of FCGR3B and homozygosity of the FcgammaRIIB-232T allele were individually strongly associated with SLE risk. Thus CN of FCGR3B, which controls IC responses and uptake by neutrophils, and variations in FCGR2B, which controls factors such as antibody production and macrophage activation, are important in SLE pathogenesis. Further interpretations of contributions to pathogenesis by FcgammaRs must be made in the context of LD involving CNV regions.

Berkley JA, Munywoki P, Ngama M, Kazungu S, Abwao J, Bett A, Lassauniére R, Kresfelder T, Cane PA, Venter M et al. 2010. Viral etiology of severe pneumonia among Kenyan infants and children. JAMA, 303 (20), pp. 2051-2057. | Citations: 177 (Scopus) | Show Abstract | Read more

CONTEXT: Pneumonia is the leading cause of childhood death in sub-Saharan Africa. Comparative estimates of the contribution of causative pathogens to the burden of disease are essential for targeted vaccine development. OBJECTIVE: To determine the viral etiology of severe pneumonia among infants and children at a rural Kenyan hospital using comprehensive and sensitive molecular diagnostic techniques. DESIGN, SETTING, AND PARTICIPANTS: Prospective observational and case-control study during 2007 in a rural Kenyan district hospital. Participants were children aged 1 day to 12 years, residing in a systematically enumerated catchment area, and who either were admitted to Kilifi District Hospital meeting World Health Organization clinical criteria for severe pneumonia or very severe pneumonia; (2) presented with mild upper respiratory tract infection but were not admitted; or (3) were well infants and children attending for immunization. MAIN OUTCOME MEASURES: The presence of respiratory viruses and the odds ratio for admission with severe disease. RESULTS: Of 922 eligible admitted patients, 759 were sampled (82% [median age, 9 months]). One or more respiratory viruses were detected in 425 of the 759 sampled (56% [95% confidence interval {CI}, 52%-60%]). Respiratory syncytial virus (RSV) was detected in 260 participants (34% [95% CI, 31%-38%]) and other respiratory viruses were detected in 219 participants (29%; 95% CI, 26%-32%), the most common being Human coronavirus 229E (n = 51 [6.7%]), influenza type A (n = 44 [5.8%]), Parainfluenza type 3 (n = 29 [3.8%]), Human adenovirus (n = 29 [3.8%]), and Human metapneumovirus (n = 23 [3.0%]). Compared with well control participants, detection of RSV was associated with severe disease (5% [corrected] in control participants; adjusted odds ratio, 6.11 [95% CI, 1.65-22.6]) while collectively, other respiratory viruses were not associated with severe disease (23% in control participants; adjusted odds ratio, 1.27 [95% CI, 0.64-2.52]). CONCLUSION: In a sample of Kenyan infants and children admitted with severe pneumonia to a rural hospital, RSV was the predominant viral pathogen.

Gething PW, Smith DL, Patil AP, Tatem AJ, Snow RW, Hay SI. 2010. Climate change and the global malaria recession. Nature, 465 (7296), pp. 342-345. | Citations: 185 (Scopus) | Show Abstract | Read more

The current and potential future impact of climate change on malaria is of major public health interest. The proposed effects of rising global temperatures on the future spread and intensification of the disease, and on existing malaria morbidity and mortality rates, substantively influence global health policy. The contemporary spatial limits of Plasmodium falciparum malaria and its endemicity within this range, when compared with comparable historical maps, offer unique insights into the changing global epidemiology of malaria over the last century. It has long been known that the range of malaria has contracted through a century of economic development and disease control. Here, for the first time, we quantify this contraction and the global decreases in malaria endemicity since approximately 1900. We compare the magnitude of these changes to the size of effects on malaria endemicity proposed under future climate scenarios and associated with widely used public health interventions. Our findings have two key and often ignored implications with respect to climate change and malaria. First, widespread claims that rising mean temperatures have already led to increases in worldwide malaria morbidity and mortality are largely at odds with observed decreasing global trends in both its endemicity and geographic extent. Second, the proposed future effects of rising temperatures on endemicity are at least one order of magnitude smaller than changes observed since about 1900 and up to two orders of magnitude smaller than those that can be achieved by the effective scale-up of key control measures. Predictions of an intensification of malaria in a warmer world, based on extrapolated empirical relationships or biological mechanisms, must be set against a context of a century of warming that has seen marked global declines in the disease and a substantial weakening of the global correlation between malaria endemicity and climate.

O'Riordan S, Hien TT, Miles K, Allen A, Quyen NN, Hung NQ, Anh DQ, Tuyen LN, Khoa DB, Thai CQ et al. 2010. Large scale screening for haemoglobin disorders in southern Vietnam: implications for avoidance and management. Br J Haematol, 150 (3), pp. 359-364. | Citations: 23 (Scopus) | Show Abstract | Read more

In order to obtain an approximate assessment of the public health burden that will be posed by the inherited disorders of haemoglobin in southern Vietnam, several thousand individuals were screened for these conditions. A smaller sample was screened for glucose-6-phosphate dehydrogenase (G6PD) deficiency. The important haemoglobin disorders identified were beta thalassaemia, haemoglobin E and a variety of different forms of alpha thalassaemia. There were sufficient G6PD-deficient individuals to materially affect malaria control programme design. The most remarkable finding was wide variation in the gene frequencies of these conditions among the ethnic groups sampled. The approximate number of babies expected to be born with clinically significant haemoglobin disorders in Vietnam was estimated from the gene-frequency data. This study emphasizes the importance of wide-scale population screening, including ethnic subgroups, to establish the requirements for inherited haemoglobin disorder programmes in resource-limited settings.

Saeed P, Blank L, Selva D, Wolbers JG, Nowak PJCM, Geskus RB, Weis E, Mourits MP, Rootman J. 2010. Primary radiotherapy in progressive optic nerve sheath meningiomas: a long-term follow-up study. Br J Ophthalmol, 94 (5), pp. 564-568. | Citations: 31 (Scopus) | Show Abstract | Read more

BACKGROUND/AIMS To report the outcome of primary radiotherapy in patients with progressive optic nerve sheath meningioma (ONSM). METHODS The clinical records of all patients were reviewed in a retrospective, observational, multicentre study. RESULTS Thirty-four consecutive patients were included. Twenty-six women and eight men received conventional or stereotactic fractionated radiotherapy, and were followed for a median 58 (range 51-156) months. Fourteen eyes (41%) showed improved visual acuity of at least two lines on the Snellen chart. In 17 (50%) eyes, the vision stabilised, while deterioration was noted in three eyes (9%). The visual outcome was not associated with age at the time of radiotherapy (p=0.83), sex (p=0.43), visual acuity at the time of presentation (p=0.22) or type of radiotherapy (p=0.35). Optic disc swelling was associated with improved visual acuity (p<0.01) and 4/11 patients with optic atrophy also showed improvement. Long-term complications were dry eyes in five patients, cataracts in three, and mild radiation retinopathy in four. CONCLUSION Primary radiotherapy for patients with ONSM is associated with long-term improvement of visual acuity and few adverse effects.

Sutherland CJ, Tanomsing N, Nolder D, Oguike M, Jennison C, Pukrittayakamee S, Dolecek C, Hien TT, do Rosário VE, Arez AP et al. 2010. Two nonrecombining sympatric forms of the human malaria parasite Plasmodium ovale occur globally. J Infect Dis, 201 (10), pp. 1544-1550. | Citations: 155 (Scopus) | Show Abstract | Read more

BACKGROUND: Malaria in humans is caused by apicomplexan parasites belonging to 5 species of the genus Plasmodium. Infections with Plasmodium ovale are widely distributed but rarely investigated, and the resulting burden of disease is not known. Dimorphism in defined genes has led to P. ovale parasites being divided into classic and variant types. We hypothesized that these dimorphs represent distinct parasite species. METHODS: Multilocus sequence analysis of 6 genetic characters was carried out among 55 isolates from 12 African and 3 Asia-Pacific countries. RESULTS: Each genetic character displayed complete dimorphism and segregated perfectly between the 2 types. Both types were identified in samples from Ghana, Nigeria, São Tomé, Sierra Leone, and Uganda and have been described previously in Myanmar. Splitting of the 2 lineages is estimated to have occurred between 1.0 and 3.5 million years ago in hominid hosts. CONCLUSIONS: We propose that P. ovale comprises 2 nonrecombining species that are sympatric in Africa and Asia. We speculate on possible scenarios that could have led to this speciation. Furthermore, the relatively high frequency of imported cases of symptomatic P. ovale infection in the United Kingdom suggests that the morbidity caused by ovale malaria has been underestimated.

Mackinnon MJ, Marsh K. 2010. The selection landscape of malaria parasites. Science, 328 (5980), pp. 866-871. | Citations: 89 (Scopus) | Show Abstract | Read more

Malaria parasites have to survive and transmit within a highly selective and ever-changing host environment. Because immunity to malaria is nonsterilizing and builds up slowly through repeated infections, commonly the parasite invades a host that is immunologically and physiologically different from its previous host. During the course of infection, the parasite must also keep pace with changes in host immune responses and red-blood-cell physiology. Here, we describe the "selection landscape" of the most virulent of the human malaria parasites, Plasmodium falciparum, and the adaptive mechanisms it uses to navigate through that landscape. Taking a cost-benefit view of parasite fitness, we consider the evolutionary outcomes of the most important forces of selection operating on the parasite, namely immunity, host death, drugs, mosquito availability, and coinfection. Given the huge potential for malaria parasite evolution in the context of the recently renewed effort to eradicate malaria, a deeper understanding of P. falciparum adaptation is essential.

Dung NTP, Duyen HTL, Thuy NTV, Ngoc TV, Chau NVV, Hien TT, Rowland-Jones SL, Dong T, Farrar J, Wills B, Simmons CP. 2010. Timing of CD8+ T cell responses in relation to commencement of capillary leakage in children with dengue. J Immunol, 184 (12), pp. 7281-7287. | Citations: 41 (Web of Science Lite) | Show Abstract | Read more

Immune activation is a feature of dengue hemorrhagic fever (DHF) and CD8+ T cell responses in particular have been suggested as having a role in the vasculopathy that characterizes this disease. By phenotyping CD8+ T cells (CD38+/HLA-DR+, CD38+/Ki-67+, or HLA-DR+/Ki-67+) in serial blood samples from children with dengue, we found no evidence of increased CD8+ T cell activation prior to the commencement of resolution of viremia or hemoconcentration. Investigations with MHC class I tetramers to detect NS3(133-142)-specific CD8+ T cells in two independent cohorts of children suggested the commencement of hemoconcentration and thrombocytopenia in DHF patients generally begins before the appearance of measurable frequencies of NS3(133-142)-specific CD8+ T cells. The temporal mismatch between the appearance of measurable surface activated or NS3(133-142)-specific CD8+ T cells suggests that these cells are sequestered at sites of infection, have phenotypes not detected by our approach, or that other mechanisms independent of CD8+ T cells are responsible for early triggering of capillary leakage in children with DHF.

Van Effelterre T, Moore MR, Fierens F, Whitney CG, White L, Pelton SI, Hausdorff WP. 2010. A dynamic model of pneumococcal infection in the United States: implications for prevention through vaccination. Vaccine, 28 (21), pp. 3650-3660. | Citations: 42 (Scopus) | Show Abstract | Read more

Universal infant vaccination with the 7-valent pneumococcal conjugate vaccine (PCV7) has nearly eliminated PCV7-serotype invasive pneumococcal disease (IPD) in young U.S. children, but has been accompanied by increases in the incidence of serotype 19A IPD. Because antibiotic-non-susceptible 19A has increased more than antibiotic-susceptible 19A, antibiotic selection pressure could be contributing to this trend. We developed a dynamic compartmental transmission model of pneumococcus to better understand the causes of this rise and to estimate the impact of vaccines or changes in antibiotic use on future IPD incidence in the U.S. in <2 year-olds. The model predicted that with current practices, serotype 19A IPD incidence will plateau at about the 2007 level over the next few years. The model suggests that antibiotic usage played a major role in the rise in antibiotic-non-susceptible 19A IPD, with a lesser contribution from PCV7 vaccination. However, hypothetical large decreases in antibiotic use starting in 2008 are predicted to yield only gradual decreases in antibiotic-non-susceptible 19A IPD. On the other hand, vaccines with modest (20%) effectiveness against 19A (or 6A or PCV7-serotypes) carriage are predicted to substantially (by 80%) decrease the incidence of IPD caused by those serotypes within 10 years of implementation. Our findings highlight that vaccine effects on colonization are key to their overall benefits. In addition, serotype changes following vaccine introduction may have multifactorial origins, with antibiotic use an important factor for resistant strains such as 19A.

Anderson TJC, Nair S, Nkhoma S, Williams JT, Imwong M, Yi P, Socheat D, Das D, Chotivanich K, Day NPJ et al. 2010. High heritability of malaria parasite clearance rate indicates a genetic basis for artemisinin resistance in western Cambodia. J Infect Dis, 201 (9), pp. 1326-1330. | Citations: 99 (Scopus) | Show Abstract | Read more

In western Cambodia, malaria parasites clear slowly from the blood after treatment with artemisinin derivatives, but it is unclear whether this results from parasite, host, or other factors specific to this population. We measured heritability of clearance rate by evaluating patients infected with identical or nonidentical parasite genotypes, using methods analogous to human twin studies. A substantial proportion (56%-58%) of the variation in clearance rate is explained by parasite genetics. This has 2 important implications: (1) selection with artemisinin derivatives will tend to drive resistance spread and (2) because heritability is high, the genes underlying parasite clearance rate may be identified by genome-wide association.

Shann F, Nohynek H, Scott JA, Hesseling A, Flanagan KL, Working Group on Nonspecific Effects of Vaccines. 2010. Randomized trials to study the nonspecific effects of vaccines in children in low-income countries. Pediatr Infect Dis J, 29 (5), pp. 457-461. | Citations: 27 (Scopus) | Show Abstract | Read more

The Expanded Program on Immunization (EPI) has led to large reductions in morbidity and mortality among children in low-income countries. However, the basic EPI schedule may no longer be optimal because of changes in vaccines, programs, and epidemiologic circumstances. In addition, evidence has accumulated that some EPI vaccines may have nonspecific effects that increase or decrease mortality from subsequent infections with other unrelated organisms. There is therefore a need for randomized trials to evaluate the effects of alternative EPI schedules on all-cause mortality, as well as vaccine efficacy against the target diseases. We have reviewed the available literature on the nonspecific effects of vaccines on mortality, and compiled a list of potential trials that might address this issue. We have then ranked the trials based on the potential importance of the results and the ethical and practical considerations. Trials of early BCG vaccination in low-birth-weight babies, early measles vaccination, and altered timing of DTP vaccination all have a high priority.

Harris JB, Faiz MA, Rahman MR, Jalil MMA, Ahsan MF, Theakston RDG, Warrell DA, Kuch U. 2010. Snake bite in Chittagong Division, Bangladesh: a study of bitten patients who developed no signs of systemic envenoming. Trans R Soc Trop Med Hyg, 104 (5), pp. 320-327. | Citations: 13 (Web of Science Lite) | Show Abstract | Read more

The demographics, epidemiology, first aid, clinical management, treatment and outcome of snake bites causing no significant signs of systemic envenoming were documented in Chittagong Medical College Hospital, Bangladesh, between May 1999 and October 2002. Among 884 patients admitted, 350 were systemically envenomed and 534 were without signs of either systemic or significant local envenoming. The average age of patients with physical evidence of snake bite but no systemic envenoming was 26.4 years. Most had been bitten on their feet or hands. Ligatures had been applied proximal to the bite site in >95% of cases and the bite site had been incised in 13%. Patients were typically discharged at 24h. Those with clinical signs of systemic envenoming resembled the non-envenomed cases demographically and epidemiologically except that they arrived at hospital significantly later than non-envenomed patients, having spent longer with traditional healers. No non-envenomed patient was treated with antivenom and none went on to develop symptoms of systemic envenoming after discharge. The potential complications and confusing signs caused by ligatures and incision demand that all patients admitted with a history of snake bite be kept under observation for 24h after admission even if they have no signs of systemic envenoming.

Sibley CH, Guerin PJ, Ringwald P. 2010. Monitoring antimalarial resistance: launching a cooperative effort. Trends Parasitol, 26 (5), pp. 221-224. | Citations: 10 (Web of Science Lite) | Show Abstract | Read more

Current information on efficacy of antimalarials is crucial to provide early warning of resistance. A collaborative effort between the Global Malaria Program of the World Health Organization (WHO) and the WorldWide Antimalarial Resistance Network (WWARN) has recently been launched. The effort is planned as a collaboration with the scientific malaria community to create a global, comprehensive, and inclusive network that will provide quality-assured information on antimalarial drug resistance.

Bonnet M, Tajahmady A, Hepple P, Ramsay A, Githui W, Gagdnidze L, Guérin PJ, Varaine F. 2010. Added value of bleach sedimentation microscopy for diagnosis of tuberculosis: a cost-effectiveness study. Int J Tuberc Lung Dis, 14 (5), pp. 571-577. | Citations: 7 (Web of Science Lite) | Show Abstract

SETTING: Bleach sedimentation is a method used to increase the diagnostic yield of sputum microscopy for countries with a high prevalence of human immunodeficiency virus (HIV) infection and limited resources. OBJECTIVES: To compare the relative cost-effectiveness of different microscopy approaches in diagnosing tuberculosis (TB) in Kenya. METHODS: An analytical decision tree model including cost and effectiveness measures of 10 combinations of direct (D) and overnight bleach (B) sedimentation microscopy was constructed. Data were drawn from the evaluation of the bleach sedimentation method on two specimens (first on the spot [1] and second morning [2]) from 644 TB suspects in a peripheral health clinic. Incremental cost per smear-positive detected case was measured. Costs included human resources and materials using a micro-costing evaluation. RESULTS: All bleach-based microscopy approaches detected significantly more cases (between 23.3% for B1 and 25.9% for B1+B2) than the conventional D1+D2 approach (21.0%). Cost per tested case ranged between respectively euro 2.7 and euro 4.5 for B1 and B1+D2+B2. B1 and B1+B2 were the most cost-effective approaches. D1+B2 and D1+B1 were good alternatives to avoid using approaches exclusively based on bleach sedimentation microscopy. CONCLUSIONS: Among several effective microscopy approaches used, including sodium hypochlorite sedimentation, only some resulted in a limited increase in the laboratory workload and would be most suitable for programmatic implementation.

Horby P. 2010. Why are so few people infected with influenza A (H5N1) despite a large exposed population? The role of host genetics INFLUENZA AND OTHER RESPIRATORY VIRUSES, 4 pp. 40-40.

Tensou B, Araya T, Telake DS, Byass P, Berhane Y, Kebebew T, Sanders EJ, Reniers G. 2010. Evaluating the InterVA model for determining AIDS mortality from verbal autopsies in the adult population of Addis Ababa. Trop Med Int Health, 15 (5), pp. 547-553. | Citations: 26 (Web of Science Lite) | Show Abstract | Read more

OBJECTIVE: To evaluate the performance of a verbal autopsy (VA) expert algorithm (the InterVA model) for diagnosing AIDS mortality against a reference standard from hospital records that include HIV serostatus information in Addis Ababa, Ethiopia. METHODS: Verbal autopsies were conducted for 193 individuals who visited a hospital under surveillance during terminal illness. Decedent admission diagnosis and HIV serostatus information are used to construct two reference standards (AIDS vs. other causes of death and TB/AIDS vs. other causes). The InterVA model is used to interpret the VA interviews; and the sensitivity, specificity and cause-specific mortality fractions are calculated as indicators of the diagnostic accuracy of the InterVA model. RESULTS: The sensitivity and specificity of the InterVA model for diagnosing AIDS are 0.82 (95% CI: 0.74-0.89) and 0.76 (95% CI: 0.64-0.86), respectively. The sensitivity and specificity for TB/AIDS are 0.91 (95% CI: 0.85-0.96) and 0.78 (95% CI: 0.63-0.89), respectively. The AIDS-specific mortality fraction estimated by the model is 61.7% (95% CI: 54-69%), which is close to 64.7% (95% CI: 57-72%) in the reference standard. The TB/AIDS mortality fraction estimated by the model is 73.6% (95% CI: 67-80%), compared to 74.1% (95% CI: 68-81%) in the reference standard. CONCLUSION: The InterVA model is an easy to use and cheap alternative to physician review for assessing AIDS mortality in populations without vital registration and medical certification of causes of death. The model seems to perform better when TB and AIDS are combined, but the sample is too small to statistically confirm that.

Sheehy SH, Atkins BA, Bejon P, Byren I, Wyllie D, Athanasou NA, Berendt AR, McNally MA. 2010. The microbiology of chronic osteomyelitis: prevalence of resistance to common empirical anti-microbial regimens. J Infect, 60 (5), pp. 338-343. | Citations: 41 (Scopus) | Show Abstract | Read more

OBJECTIVES: This study describes the microbiological spectrum of chronic osteomyelitis and so guides the choice of empirical antibiotics for this condition. METHODS: We performed a prospective review of a 166 prospective patient series of chronic osteomyelitis from Oxford, UK in which a standardised surgical sampling protocol was used. RESULTS: Staphylococcus aureus was most commonly isolated (32%) amongst a wide range of organisms including gram negative bacilli, anaerobes and coagulase negative staphylococci. Low grade pathogens were not confined to patients with a history of metalwork, a high proportion of cases were polymicrobial (29%) and culture negative cases were common (28%). No clear predictors of causative organism could be established. Many isolates were found to be resistant to commonly used empirical anti-microbial regimens. CONCLUSIONS: The wide range of causative organisms and degree of resistance to commonly used anti-microbials supports the importance of extensive intra-operative sampling and provides important information to guide clinicians' choice of empirical antibiotics.

Blaauw D, Erasmus E, Pagaiya N, Tangcharoensathein V, Mullei K, Mudhune S, Goodman C, English M, Lagarde M. 2010. Policy interventions that attract nurses to rural areas: a multicountry discrete choice experiment. Bull World Health Organ, 88 (5), pp. 350-356. | Show Abstract | Read more

OBJECTIVE: To evaluate the relative effectiveness of different policies in attracting nurses to rural areas in Kenya, South Africa and Thailand using data from a discrete choice experiment (DCE). METHODS: A labelled DCE was designed to model the relative effectiveness of both financial and non-financial strategies designed to attract nurses to rural areas. Data were collected from over 300 graduating nursing students in each country. Mixed logit models were used for analysis and to predict the uptake of rural posts under different incentive combinations. FINDINGS: Nurses' preferences for different human resource policy interventions varied significantly between the three countries. In Kenya and South Africa, better educational opportunities or rural allowances would be most effective in increasing the uptake of rural posts, while in Thailand better health insurance coverage would have the greatest impact. CONCLUSION: DCEs can be designed to help policy-makers choose more effective interventions to address staff shortages in rural areas. Intervention packages tailored to local conditions are more likely to be effective than standardized global approaches.

Woodrow CJ, Bustamante LY, Bacon DJ, Udhayakumar V. 2010. Plasmodium falciparum ATP6 Not under Selection during Introduction of Artemisinin Combination Therapy in Peru Antimicrobial Agents and Chemotherapy, 54 (5), pp. 2280-2281. | Read more

Thapa R, Banskota N, Pokharel J, Subedi BH, Basnyat B. 2010. Another typhoid patient from Japan. J Travel Med, 17 (3), pp. 199-200. | Citations: 2 (Web of Science Lite) | Show Abstract | Read more

Typhoid treatment was empirically started in a Japanese patient with undifferentiated fever in Nepal since Japanese tourists, unlike most Americans and Europeans to South Asia, are unable to obtain typhoid vaccination in Japan even for travel to this area of high endemicity. Subsequently, his blood culture grew out Salmonella typhi.

Jarrín I, Geskus R, Pérez-Hoyos S, del Amo J. 2010. [Analytical methods in cohort studies of patients with HIV infection]. Enferm Infecc Microbiol Clin, 28 (5), pp. 298-303. | Citations: 2 (Scopus) | Show Abstract | Read more

This paper provides an overview of the main statistical methods used in the analysis of data from cohort studies and presents a detailed description of the way these methods are applied in HIV/AIDS research. First, we describe methods for analyzing events in person-time data. Second, we present survival methods for the analysis of time-to-event data. In this context, we illustrate the application of these methods to describe the AIDS incubation period and survival from HIV seroconversion, to determine the factors and biological markers associated with disease progression, and to evaluate effectiveness of therapy. The review ends by illustrating the statistical methods used for the analysis of markers measured repeatedly over time.

van den Heuvel MEN, van der Lee JH, Cornelissen EAM, Bemelman FJ, Hoitsma A, Geskus RB, Bouts AHM, Groothoff JW. 2010. Transition to the adult nephrologist does not induce acute renal transplant rejection. Nephrol Dial Transplant, 25 (5), pp. 1662-1667. | Citations: 15 (Scopus) | Show Abstract | Read more

BACKGROUND: In spite of the overall increased renal graft survival, long-term allograft survival has remained least successful in adolescent recipients. A major change in their care is the transition from the paediatric to the adult nephrology unit. METHODS: To analyse the effect of transition on the acute rejection frequency and graft survival, we performed a historical cohort study in all patients transplanted at the paediatric unit between 1980 and 2004. Data were obtained by reviewing medical charts in two of the four Dutch pediatric renal transplantation centers from time of transplantation until 3 years after transition. For analysis, we used a Cox proportional hazards model. RESULTS: The cohort consisted of 162 patients: 133 native Dutch and 29 immigrant patients. Transition occurred at a mean age of 18 years (range 14-22). At transition, 72% had a functioning allograft. Acute rejections occurred in 92/162 patients before (median follow-up 4.8 years, range 0.2-12.8) and in 15/116 patients after transition (median follow-up 3.0 years, range 1.6-3.0). Most rejections (62%) occurred within the first year after transplantation. The relative risk of acute rejections after transition in comparison to before transition was 0.10 [95% confidence interval (95% CI) 0.04-0.28] in Dutch patients and 0.69 (95% CI 0.33-1.40) in immigrant patients. In the 3 years before transition, 28/154 patients (18%) experienced graft failure compared to 19/116 patients (16%) in the 3 years after transition. CONCLUSIONS: The risk for acute rejection decreases after transition to the adult unit. There is less risk reduction in immigrant patients. Nephrologists should pay special attention to these patients.

Willcocks LC, Carr EJ, Niederer HA, Rayner TF, Williams TN, Yang W, Scott JAG, Urban BC, Peshu N, Vyse TJ et al. 2010. A defunctioning polymorphism in FCGR2B is associated with protection against malaria but susceptibility to systemic lupus erythematosus. Proc Natl Acad Sci U S A, 107 (17), pp. 7881-7885. | Citations: 92 (Scopus) | Show Abstract | Read more

Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease more prevalent in people of African and Asian origin than Caucasian origin. FcgammaRIIb is an inhibitory Fc receptor with a critical role in immune regulation. Mouse data suggest that FcgammaRIIb deficiency increases susceptibility to autoimmune disease but protects against infection. We show that a SNP in human FCGR2B that abrogates receptor function is strongly associated with susceptibility to SLE in both Caucasians and Southeast Asians. The minor allele of this SNP is more common in Southeast Asians and Africans, populations from areas where malaria is endemic, than in Caucasians. We show that homozygosity for the minor allele is associated with substantial protection against severe malaria in an East African population (odds ratio = 0.56; P = 7.1 x 10(-5)). This protective effect against malaria may contribute to the higher frequency of this SNP and hence, SLE in Africans and Southeast Asians.

Imwong M, Dondorp AM, Nosten F, Yi P, Mungthin M, Hanchana S, Das D, Phyo AP, Lwin KM, Pukrittayakamee S et al. 2010. Exploring the contribution of candidate genes to artemisinin resistance in Plasmodium falciparum. Antimicrob Agents Chemother, 54 (7), pp. 2886-2892. | Citations: 88 (Scopus) | Show Abstract | Read more

The reduced in vivo sensitivity of Plasmodium falciparum has recently been confirmed in western Cambodia. Identifying molecular markers for artemisinin resistance is essential for monitoring the spread of the resistant phenotype and identifying the mechanisms of resistance. Four candidate genes, including the P. falciparum mdr1 (pfmdr1) gene, the P. falciparum ATPase6 (pfATPase6) gene, the 6-kb mitochondrial genome, and ubp-1, encoding a deubiquitinating enzyme, of artemisinin-resistant P. falciparum strains from western Cambodia were examined and compared to those of sensitive strains from northwestern Thailand, where the artemisinins are still very effective. The artemisinin-resistant phenotype did not correlate with pfmdr1 amplification or mutations (full-length sequencing), mutations in pfATPase6 (full-length sequencing) or the 6-kb mitochondrial genome (full-length sequencing), or ubp-1 mutations at positions 739 and 770. The P. falciparum CRT K76T mutation was present in all isolates from both study sites. The pfmdr1 copy numbers in western Cambodia were significantly lower in parasite samples obtained in 2007 than in those obtained in 2005, coinciding with a local change in drug policy replacing artesunate-mefloquine with dihydroartemisinin-piperaquine. Artemisinin resistance in western Cambodia is not linked to candidate genes, as was suggested by earlier studies.

de Villiers EP, Gallardo C, Arias M, da Silva M, Upton C, Martin R, Bishop RP. 2010. Phylogenomic analysis of 11 complete African swine fever virus genome sequences. Virology, 400 (1), pp. 128-136. | Show Abstract | Read more

Viral molecular epidemiology has traditionally analyzed variation in single genes. Whole genome phylogenetic analysis of 123 concatenated genes from 11 ASFV genomes, including E75, a newly sequenced virulent isolate from Spain, identified two clusters. One contained South African isolates from ticks and warthog, suggesting derivation from a sylvatic transmission cycle. The second contained isolates from West Africa and the Iberian Peninsula. Two isolates, from Kenya and Malawi, were outliers. Of the nine genomes within the clusters, seven were within p72 genotype 1. The 11 genomes sequenced comprised only 5 of the 22 p72 genotypes. Comparison of synonymous and non-synonymous mutations at the genome level identified 20 genes subject to selection pressure for diversification. A novel gene of the E75 virus evolved by the fusion of two genes within the 360 multicopy family. Comparative genomics reveals high diversity within a limited sample of the ASFV viral gene pool.

Nosten FH. 2010. Pyronaridine-artesunate for uncomplicated falciparum malaria. Lancet, 375 (9724), pp. 1413-1414. | Citations: 5 (Scopus) | Read more

Crawley J, Chu C, Mtove G, Nosten F. 2010. Malaria in children. Lancet, 375 (9724), pp. 1468-1481. | Citations: 49 (Scopus) | Show Abstract | Read more

The past decade has seen an unprecedented surge in political commitment and international funding for malaria control. Coverage with existing control methods (ie, vector control and artemisinin-based combination therapy) is increasing, and, in some Asian and African countries, childhood morbidity and mortality from malaria caused by Plasmodium falciparum are starting to decline. Consequently, there is now renewed interest in the possibility of malaria elimination. But the ability of the parasite to develop resistance to antimalarial drugs and increasing insecticide resistance of the vector threaten to reduce and even reverse current gains. Plasmodium vivax, with its dormant liver stage, will be particularly difficult to eliminate, and access to effective and affordable treatment at community level is a key challenge. New drugs and insecticides are needed urgently, while use of an effective vaccine as part of national malaria control programmes remains an elusive goal. This Seminar, which is aimed at clinicians who manage children with malaria, especially in resource-poor settings, discusses present knowledge and controversies in relation to the epidemiology, pathophysiology, diagnosis, treatment, and prevention of malaria in children.

Snow RW, Marsh K. 2010. Malaria in Africa: progress and prospects in the decade since the Abuja Declaration. Lancet, 376 (9735), pp. 137-139. | Citations: 65 (Scopus) | Read more

Talbert AWA, Mwaniki M, Mwarumba S, Newton CRJC, Berkley JA. 2010. Invasive bacterial infections in neonates and young infants born outside hospital admitted to a rural hospital in Kenya. Pediatr Infect Dis J, 29 (10), pp. 945-949. | Citations: 25 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Bacterial sepsis is thought to be a major cause of young infant deaths in low-income countries, but there are few precise estimates of its burden or causes. We studied invasive bacterial infections (IBIs) in young infants, born at home or in first-level health units ("outborn") who were admitted to a Kenyan rural district hospital during an 8-year period. METHODS: Clinical and microbiologic data, from admission blood cultures and cerebrospinal fluid cultures on all outborn infants aged less than 60 days admitted from 2001 to 2009, were examined to determine etiology of IBI and antimicrobial susceptibilities. RESULTS: Of the 4467 outborn young infants admitted, 748 (17%) died. Five hundred five (11%) had IBI (10% bacteremia and 3% bacterial meningitis), with a case fatality of 33%. The commonest organisms were Klebsiella spp., Staphylococcus aureus, Streptococcus pneumoniae, Group B Streptococcus, Acinetobacter spp., Escherichia coli, and Group A Streptococcus. Notably, some blood culture isolates were seen in outborn neonates in the first week of life but not in inborns: Salmonella, Aeromonas, and Vibrio spp. Eighty-one percent of isolates were susceptible to penicillin and/or gentamicin and 84% to ampicillin and/or gentamicin. There was a trend to increasing in vitro antimicrobial resistance to these combinations from 2008 but without a worse outcome. CONCLUSIONS: IBI is common in outborn young infants admitted to rural African hospitals with a high mortality. Presumptive antimicrobial use is justified for all young infants admitted to the hospital.

Awab GR, Pukrittayakamee S, Imwong M, Dondorp AM, Woodrow CJ, Lee SJ, Day NPJ, Singhasivanon P, White NJ, Kaker F. 2010. Dihydroartemisinin-piperaquine versus chloroquine to treat vivax malaria in Afghanistan: an open randomized, non-inferiority, trial. Malar J, 9 (1), pp. 105. | Citations: 37 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Afghanistan's national guidelines recommend chloroquine for the treatment of Plasmodium vivax infection, the parasite responsible for the majority of its malaria burden. Chloroquine resistance in P. vivax is emerging in Asia. Therapeutic responses across Afghanistan have not been evaluated in detail. METHODS: Between July 2007 and February 2009, an open-label, randomized controlled trial of chloroquine and dihydroartemisinin-piperaquine in patients aged three months and over with slide-confirmed P. vivax mono-infections was conducted. Consistent with current national guidelines, primaquine was not administered. Subjects were followed up daily during the acute phase of illness (days 0-3) and weekly until day 56. The primary endpoint was the overall cumulative parasitological failure rate at day 56 after the start of treatment, with the hypothesis being that dihydroartemisinin-piperaquine was non-inferior compared to chloroquine (Delta = 5% difference in proportion of failures). RESULTS: Of 2,182 individuals with positive blood films for P. vivax, 536 were enrolled in the trial. The day 28 cure rate was 100% in both treatment groups. Parasite clearance was more rapid with dihydroartemisinin-piperaquine than chloroquine. At day 56, there were more recurrent infections in the chloroquine arm (8.9%, 95% CI 6.0-13.1%) than the dihydroartemisinin-piperaquine arm (2.8%, 95% CI 1.4-5.8%), a difference in cumulative recurrence rate of 6.1% (2-sided 90%CI +2.6 to +9.7%). The log-rank test comparing the survival curves confirmed the superiority of dihydroartemisinin-piperaquine over chloroquine (p = 0.003). Multivariate analysis showed that a lower initial haemoglobin concentration was also independently associated with recurrence. Both regimens were well tolerated and no serious adverse events were reported. CONCLUSIONS: Chloroquine remains an efficacious treatment for the treatment of vivax malaria in Afghanistan. In a setting where radical therapy cannot be administered, dihydroartemisinin-piperaquine provides additional benefit in terms of post-treatment prophylaxis, reducing the incidence of recurrence from 4-8 weeks after treatment.

Okiro EA, Snow RW. 2010. The relationship between reported fever and Plasmodium falciparum infection in African children. Malar J, 9 (1), pp. 99. | Citations: 24 (Scopus) | Show Abstract | Read more

BACKGROUND: Fever has traditionally served as the entry point for presumptive treatment of malaria in African children. However, recent changes in the epidemiology of malaria across many places in Africa would suggest that the predictive accuracy of a fever history as a marker of disease has changed prompting calls for the change to diagnosis-based treatment strategies. METHODS: Using data from six national malaria indicator surveys undertaken between 2007 and 2009, the relationship between childhood (6-59 months) reported fever on the day of survey and the likelihood of coincidental Plasmodium falciparum infection recorded using a rapid diagnostic test was evaluated across a range of endemicities characteristic of Africa today. RESULTS: Of 16,903 children surveyed, 3% were febrile and infected, 9% were febrile without infection, 12% were infected but were not febrile and 76% were uninfected and not febrile. Children with fever on the day of the survey had a 1.98 times greater chance of being infected with P. falciparum compared to children without a history of fever on the day of the survey after adjusting for age and location (OR 1.98; 95% CI 1.74-2.34). There was a strong linear relationship between the percentage of febrile children with infection and infection prevalence (R2 = 0.9147). The prevalence of infection in reported fevers was consistently greater than would be expected solely by chance and this increased with increasing transmission intensity. The data suggest that in areas where community-based infection prevalence in childhood is above 34-37%, 50% or more of fevers are likely to be associated with infection. CONCLUSION: The potential benefits of diagnosis will depend on the prevalence of infection among children who report fever. The study has demonstrated a predictable relationship between parasite prevalence in the community and risks of infection among febrile children suggesting that current maps of parasite prevalence could be used to guide diagnostic strategies in Africa.

Phu NH, Tuan PQ, Day N, Mai NTH, Chau TTH, Chuong LV, Sinh DX, White NJ, Farrar J, Hien TT. 2010. Randomized controlled trial of artesunate or artemether in Vietnamese adults with severe falciparum malaria. Malar J, 9 (1), pp. 97. | Citations: 22 (Scopus) | Show Abstract | Read more

BACKGROUND: Both artemether and artesunate have been shown to be superior to quinine for the treatment of severe falciparum malaria in Southeast Asian adults, although the magnitude of the superiority has been greater for artesunate than artemether. These two artemisinin derivatives had not been compared in a randomized trial. METHODS: A randomized double blind trial in 370 adults with severe falciparum malaria; 186 received intramuscular artesunate (2.4 mg/kg immediately followed by 1.2 mg/kg at 12 hours then 24 hours then daily) and 184 received intramuscular artemether (3.6 mg per kilogram immediately followed by 1.8 mg per kilogram daily) was conducted in Viet Nam. Both drugs were given for a minimum of 72 hours. RESULTS: There were 13 deaths in the artesunate group (7 percent) and 24 in the artemether group (13 percent); P = 0.052; relative risk of death in the patients given artesunate, 0.54; (95 percent confidence interval 0.28-1.02). Parasitaemia declined more rapidly in the artesunate group. Both drugs were very well tolerated. CONCLUSIONS: Intramuscular artesunate may be superior to intramuscular artemether for the treatment of severe malaria in adults.

Anderson TJC, Williams JT, Nair S, Sudimack D, Barends M, Jaidee A, Price RN, Nosten F. 2010. Inferred relatedness and heritability in malaria parasites. Proc Biol Sci, 277 (1693), pp. 2531-2540. | Citations: 28 (Scopus) | Show Abstract | Read more

Malaria parasites vary in phenotypic traits of biomedical or biological interest such as growth rate, virulence, sex ratio and drug resistance, and there is considerable interest in identifying the genes that underlie this variation. An important first step is to determine trait heritability (H(2)). We evaluate two approaches to measuring H(2) in natural parasite populations using relatedness inferred from genetic marker data. We collected single-clone Plasmodium falciparum infections from 185 patients from the Thailand-Burma border, monitored parasite clearance following treatment with artemisinin combination therapy (ACT), measured resistance to six antimalarial drugs and genotyped parasites using 335 microsatellites. We found strong relatedness structure. There were 27 groups of two to eight clonally identical (CI) parasites, and 74 per cent of parasites showed significant relatedness to one or more other parasites. Initially, we used matrices of allele sharing and variance components (VC) methods to estimate H(2). Inhibitory concentrations (IC(50)) for six drugs showed significant H(2) (0.24 to 0.79, p = 0.06 to 2.85 x 10(-9)), demonstrating that this study design has adequate power. However, a phenotype of current interest--parasite clearance following ACT--showed no detectable heritability (H(2) = 0-0.09, ns) in this population. The existence of CI parasites allows the use of a simple ANOVA approach for quantifying H(2), analogous to that used in human twin studies. This gave similar results to the VC method and requires considerably less genotyping information. We conclude (i) that H(2) can be effectively measured in malaria parasite populations using minimal genotype data, allowing rational design of genome-wide association studies; and (ii) while drug response (IC(50)) shows significant H(2), parasite clearance following ACT was not heritable in the population studied.

Syhavong B, Rasachack B, Smythe L, Rolain J-M, Roque-Afonso A-M, Jenjaroen K, Soukkhaserm V, Phongmany S, Phetsouvanh R, Soukkhaserm S et al. 2010. The infective causes of hepatitis and jaundice amongst hospitalised patients in Vientiane, Laos. Trans R Soc Trop Med Hyg, 104 (7), pp. 475-483. | Citations: 27 (Scopus) | Show Abstract | Read more

There is little information on the diverse infectious causes of jaundice and hepatitis in the Asiatic tropics. Serology (hepatitis A, B, C and E, leptospirosis, dengue, rickettsia), antigen tests (dengue), PCR assays (hepatitis A, C and E) and blood cultures (septicaemia) were performed on samples from 392 patients admitted with jaundice or raised transaminases (> or =x3) to Mahosot Hospital, Vientiane, Laos over 3 years. Conservative definitions suggested diagnoses of dengue (8.4%), rickettsioses (7.3%), leptospirosis (6.8%), hepatitis B (4.9%), hepatitis C (4.9%), community-acquired septicaemia (3.3%) and hepatitis E (1.6%). Although anti-hepatitis A virus (HAV) IgM antibody results suggested that 35.8% of patients had acute HAV infections, anti-HAV IgG antibody avidity and HAV PCR suggested that 82% had polyclonal activation and not acute HAV infections. Scrub typhus, murine typhus or leptospirosis were present in 12.8% of patients and were associated with meningism and relatively low AST and ALT elevation. These patients would be expected to respond to empirical doxycycline therapy which, in the absence of virological diagnosis and treatment, may be an appropriate cost-effective intervention in Lao patients with jaundice/hepatitis.

Dondorp AM, Yeung S, White L, Nguon C, Day NPJ, Socheat D, von Seidlein L. 2010. Artemisinin resistance: current status and scenarios for containment. Nat Rev Microbiol, 8 (4), pp. 272-280. | Citations: 402 (Scopus) | Show Abstract | Read more

Artemisinin combination therapies are the first-line treatments for uncomplicated Plasmodium falciparum malaria in most malaria-endemic countries. Recently, partial artemisinin-resistant P. falciparum malaria has emerged on the Cambodia-Thailand border. Exposure of the parasite population to artemisinin monotherapies in subtherapeutic doses for over 30 years, and the availability of substandard artemisinins, have probably been the main driving force in the selection of the resistant phenotype in the region. A multifaceted containment programme has recently been launched, including early diagnosis and appropriate treatment, decreasing drug pressure, optimising vector control, targeting the mobile population, strengthening management and surveillance systems, and operational research. Mathematical modelling can be a useful tool to evaluate possible strategies for containment.

Tantibhedhyangkul W, Angelakis E, Tongyoo N, Newton PN, Moore CE, Phetsouvanh R, Raoult D, Rolain J-M. 2010. Intrinsic fluoroquinolone resistance in Orientia tsutsugamushi. Int J Antimicrob Agents, 35 (4), pp. 338-341. | Citations: 21 (Scopus) | Show Abstract | Read more

Scrub typhus is a public health concern for a population of over a billion humans, with an estimated incidence of one million cases/year in endemic areas. Although doxycycline remains the standard therapy, fluoroquinolones have been used successfully in a few patients. However, there is also clinical evidence that fluoroquinolones are ineffective in the treatment of scrub typhus. To clarify this matter, we determined the in vitro susceptibility of Orientia tsutsugamushi strain Kato to ciprofloxacin and ofloxacin and sequenced the quinolone resistance-determining region (QRDR) of the gyrA gene, the target of fluoroquinolones, of 18 fresh isolates from the Lao PDR. Orientia tsutsugamushi strain Kato was resistant to ciprofloxacin and ofloxacin in vitro (minimum inhibitory concentration=8 microg/mL). All sequences obtained, including those from the two available genomes of O. tsutsugamushi (strains Boryong and Ikeda), had a Ser83Leu mutation in their QRDR domain that is known to be associated with fluoroquinolone resistance. These findings re-emphasise the usefulness of in silico analysis for the prediction of antibiotic resistance and suggest that fluoroquinolones should not be used in the treatment of scrub typhus.

Brouwer AE, Teparrukkul P, Rajanuwong A, Chierakul W, Mahavanakul W, Chantratita W, White NJ, Harrison TS. 2010. Cerebrospinal fluid HIV-1 viral load during treatment of cryptococcal Meningitis. J Acquir Immune Defic Syndr, 53 (5), pp. 668-669. | Citations: 5 (Scopus) | Read more

Nair S, Nkhoma S, Nosten F, Mayxay M, French N, Whitworth J, Anderson T. 2010. Genetic changes during laboratory propagation: copy number At the reticulocyte-binding protein 1 locus of Plasmodium falciparum. Mol Biochem Parasitol, 172 (2), pp. 145-148. | Citations: 7 (Web of Science Lite) | Show Abstract | Read more

Comparative genomic hybridization studies have revealed elevated copy number (CN) at the reticulocyte-binding protein 1 gene (PfRh1) in fast growing lab-adapted parasites, while genetic manipulation demonstrates a causal link between cell invasion and PfRh1 CN. We therefore examined PfRh1 copy number variation (CNV) in 202 single clone parasite isolates from four countries to quantify the extent of CNV within natural populations. Surprisingly, we found that no natural parasite infections showed elevated CN. In contrast, 4/28 independent laboratory reference strains show elevated CN. One possibility is that amplification of PfRh1 (or neighboring loci) is selected during laboratory culture. In the case of FCR3 group of parasites, clone trees show that PfRh1 amplification arose in laboratory lines following establishment in culture. These data show that CNV at PfRh1 is rare or non-existent in natural populations, but can arise during laboratory propagation. We conclude that PfRh1 CNV is not an important determinant of gene expression, cell invasion or growth rate in natural parasite populations.

Pukrittayakamee S, Imwong M, Chotivanich K, Singhasivanon P, Day NPJ, White NJ. 2010. A comparison of two short-course primaquine regimens for the treatment and radical cure of Plasmodium vivax malaria in Thailand. Am J Trop Med Hyg, 82 (4), pp. 542-547. | Citations: 22 (Scopus) | Show Abstract | Read more

Thai adult males (N = 85) with acute Plasmodium vivax malaria and normal glucose-6-phosphate dehydrogenase screening were randomized to receive 30 mg or 60 mg primaquine daily for 7 days (N = 43 and 42, respectively). The regimens were well tolerated and all patients recovered fully. Median fever clearance (47 hours; range 4 to 130 hours), mean + or - SD parasite clearance times (87.7 + or - 25.3 hours), gametocyte clearance, and adverse effects were similar in the 2 groups. Two patients, 1 from each group, had a 30% reduction in hematocrit. The cumulative 28 day relapse rate (95% confidence interval) by Kaplan Meier survival analysis was 29% (16-49%) in the 30 mg group compared with 7% (2-24%) in the 60 mg group; P = 0.027. Comparison with previous data obtained at this same site suggests that the recurrences comprised approximately 17% recrudescences and 12% relapses in the 30 mg/day group compared with 3% recrudescences and 4% relapses in the 60 mg/day group. These data suggest that the dose-response relationships for primaquine's asexual stage and hypnozoitocidal activities in-vivo are different. A 1 week course of primaquine 60 mg daily is an effective treatment of vivax malaria in this region.

Abubakar SB, Abubakar IS, Habib AG, Nasidi A, Durfa N, Yusuf PO, Larnyang S, Garnvwa J, Sokomba E, Salako L et al. 2010. Pre-clinical and preliminary dose-finding and safety studies to identify candidate antivenoms for treatment of envenoming by saw-scaled or carpet vipers (Echis ocellatus) in northern Nigeria. Toxicon, 55 (4), pp. 719-723. | Citations: 35 (Web of Science Lite) | Show Abstract | Read more

The aim of this study was to identify candidate antivenoms with specific activity against the venom of the saw-scaled or carpet viper (Echis ocellatus) in northern Nigeria, where bites by this species cause great morbidity and mortality but where effective antivenoms have become scarce and unaffordable. Selected antivenoms were destined to be compared by randomised controlled clinical trials (RCTs). Standard pre-clinical neutralisation assays were carried out in rodents. We included two licensed antivenoms of established clinical efficacy and 6 candidate antivenoms. Although 6 of the tested antivenoms showed promising efficacy, all but 3 were excluded from further study because of inadequate pre-clinical efficacy or because they were unavailable or unaffordable for the anticipated RCTs. Median effective doses (ED(50)) of the remaining three candidate antivenoms suggested that the following doses might neutralise the maximum observed venom yield of 24.8 mg (dry weight) of venom milked from captive E. ocellatus: 10 ml of MicroPharm "EchiTAb G" (ET-G) antivenom; 30 ml of Instituto Clodomiro Picado "EchiTAb-Plus-ICP" (ET-Plus) antivenom; 50 ml of VacSera, Cairo "EgyVac" antivenom. A preliminary clinical dose-finding and safety study of these three antivenoms was carried out in 24 patients with incoagulable blood after E. ocellatus bites who were not severely envenomed. A 3+3 dose escalation design was employed. Initial doses of 10 ml ET-G and 30 ml ET-Plus restored blood coagulability in groups of 6 patients with early mild reactions (pruritus only) in not more than one third of them. EgyVac antivenom did not fulfil efficacy or safety criteria in 12 patients. On the basis of these results, ET-G and ET-Plus were selected for comparison in a RCT.

Yeo TW, Lampah DA, Tjitra E, Gitawati R, Darcy CJ, Jones C, Kenangalem E, McNeil YR, Granger DL, Lopansri BK et al. 2010. Increased asymmetric dimethylarginine in severe falciparum malaria: association with impaired nitric oxide bioavailability and fatal outcome. PLoS Pathog, 6 (4), pp. e1000868. | Citations: 45 (Web of Science Lite) | Show Abstract | Read more

Asymmetrical dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthase (NOS), is a predictor of mortality in critical illness. Severe malaria (SM) is associated with decreased NO bioavailability, but the contribution of ADMA to the pathogenesis of impaired NO bioavailability and adverse outcomes in malaria is unknown. In adults with and without falciparum malaria, we tested the hypotheses that plasma ADMA would be: 1) increased in proportion to disease severity, 2) associated with impaired vascular and pulmonary NO bioavailability and 3) independently associated with increased mortality. We assessed plasma dimethylarginines, exhaled NO concentrations and endothelial function in 49 patients with SM, 78 with moderately severe malaria (MSM) and 19 healthy controls (HC). Repeat ADMA and endothelial function measurements were performed in patients with SM. Multivariable regression was used to assess the effect of ADMA on mortality and NO bioavailability. Plasma ADMA was increased in SM patients (0.85 microM; 95% CI 0.74-0.96) compared to those with MSM (0.54 microM; 95%CI 0.5-0.56) and HCs (0.64 microM; 95%CI 0.58-0.70; p<0.001). ADMA was an independent predictor of mortality in SM patients with each micromolar elevation increasing the odds of death 18 fold (95% CI 2.0-181; p = 0.01). ADMA was independently associated with decreased exhaled NO (r(s) = -0.31) and endothelial function (r(s) = -0.32) in all malaria patients, and with reduced exhaled NO (r(s) = -0.72) in those with SM. ADMA is increased in SM and associated with decreased vascular and pulmonary NO bioavailability. Inhibition of NOS by ADMA may contribute to increased mortality in severe malaria.

Poespoprodjo JR, Hasanuddin A, Fobia W, Sugiarto P, Kenangalem E, Lampah DA, Tjitra E, Price RN, Anstey NM. 2010. Severe congenital malaria acquired in utero. Am J Trop Med Hyg, 82 (4), pp. 563-565. | Citations: 13 (Scopus) | Show Abstract | Read more

Vertical transmission of Plasmodium falciparum is under-recognized and usually associated with asymptomatic low-level parasitemia at birth. We report symptomatic congenital malaria presenting as a neonatal sepsis syndrome. The presence at birth of a high asexual parasitemia, gametocytemia, and splenomegaly indicated in utero rather than intrapartum transmission. The neonate was successfully treated with intravenous artesunate followed by oral dihydroartemisinin-piperaquine, without apparent adverse effects.

Mwangome M, Prentice A, Plugge E, Nweneka C. 2010. Determinants of appropriate child health and nutrition practices among women in rural Gambia. J Health Popul Nutr, 28 (2), pp. 167-172. | Citations: 21 (Scopus) | Show Abstract | Read more

Health education and awareness involves providing knowledge about causes of illness and choices to promote a change in individual behaviour and, thus, improves survival of individuals. Studies have, however, shown that improved knowledge and awareness is not always translated into appropriate actions. This study aimed at exploring the factors determining mothers' choices of appropriate child health and nutrition practices in the Gambia. Eight focus-group discussions (FGDs) were held with 63 women whose children had been seen at the Keneba MRC Clinic within the 12 months preceding the study. The FGDs were analyzed using a thematic framework. Gender inequality, presence or absence of support networks, alternative explanatory models of malnutrition, and poverty were identified as the main factors that would determine the ability of a mother to practise what she knows about child health and nutrition. The findings highlight the need to consider the broader social, cultural and economic factors, including the value of involving men in childcare, when designing nutritional interventions.

Nackers F, Broillet F, Oumarou D, Djibo A, Gaboulaud V, Guerin PJ, Rusch B, Grais RF, Captier V. 2010. Effectiveness of ready-to-use therapeutic food compared to a corn/soy-blend-based pre-mix for the treatment of childhood moderate acute malnutrition in Niger. J Trop Pediatr, 56 (6), pp. 407-413. | Citations: 37 (Scopus) | Show Abstract | Read more

Standard nutritional treatment of moderate acute malnutrition (MAM) relies on fortified blended flours though their importance to treat this condition is a matter of discussion. With the newly introduced World Health Organization growth standards, more children at an early stage of malnutrition will be treated following the dietary protocols as for severe acute malnutrition, including ready-to-use therapeutic food (RUTF). We compared the effectiveness of RUTF and a corn/soy-blend (CSB)-based pre-mix for the treatment of MAM in the supplementary feeding programmes (SFPs) supported by Médecins Sans Frontières, located in the Zinder region (south of Niger). Children measuring 65 to <110 cm, newly admitted with MAM [weight-for-height (WHM%) between 70% and <80% of the NCHS median] were randomly allocated to receive either RUTF (Plumpy'Nut®, 1000 kcal day(-1)) or a CSB pre-mix (1231 kcal day(-1)). Other interventions were similar in both groups (e.g. weekly family ration and ration at discharge). Children were followed weekly up to recovery (WHM% ≥ 85% for 2 consecutive weeks). In total, 215 children were recruited in the RUTF group and 236 children in the CSB pre-mix group with an overall recovery rate of 79.1 and 64.4%, respectively (p < 0.001). There was no evidence for a difference between death, defaulter and non-responder rates. More transfers to the inpatient Therapeutic Feeding Centre (I-TFC) were observed in the CSB pre-mix group (19.1%) compared to the RUTF group (9.3%) (p = 0.003). The average weight gain up to discharge was 1.08 g kg(-1) day(-1) higher in the RUTF group [95% confidence interval: 0.46-1.70] and the length of stay was 2 weeks shorter in the RUTF group (p < 0.001). For the treatment of childhood MAM in Niger, RUTF resulted in a higher weight gain, a higher recovery rate, a shorter length of stay and a lower transfer rate to the I-TFC compared to a CSB pre-mix. This might have important implications on the efficacy and the quality of SFPs.

Leimanis ML, Jaidee A, Sriprawat K, Kaewpongsri S, Suwanarusk R, Barends M, Phyo AP, Russell B, Renia L, Nosten F. 2010. Plasmodium vivax susceptibility to ferroquine. Antimicrob Agents Chemother, 54 (5), pp. 2228-2230. | Citations: 20 (Scopus) | Show Abstract | Read more

The novel organometallic chloroquine analog ferroquine (SSR 97193) is effective against chloroquine-resistant Plasmodium falciparum. The ex vivo efficacy of ferroquine against Plasmodium vivax isolates was tested. Ferroquine has a potent ex vivo effect on P. vivax schizont maturation (median 50% inhibitory concentration, 15 nM; n = 42). No significant cross-sensitivity between ferroquine and other antimalarials was detected. This drug may be a suitable replacement for chloroquine in the treatment of drug-resistant P. vivax malaria.

Horby P, Sudoyo H, Viprakasit V, Fox A, Thai PQ, Yu H, Davila S, Hibberd M, Dunstan SJ, Monteerarat Y et al. 2010. What is the evidence of a role for host genetics in susceptibility to influenza A/H5N1? Epidemiol Infect, 138 (11), pp. 1550-1558. | Citations: 31 (Web of Science Lite) | Show Abstract | Read more

The apparent family clustering of avian influenza A/H5N1 has led several groups to postulate the existence of a host genetic influence on susceptibility to A/H5N1, yet the role of host factors on the risk of A/H5N1 disease has received remarkably little attention compared to the efforts focused on viral factors. We examined the epidemiological patterns of human A/H5N1 cases, their possible explanations, and the plausibility of a host genetic effect on susceptibility to A/H5N1 infection. The preponderance of familial clustering of cases and the relative lack of non-familial clusters, the occurrence of related cases separated by time and place, and the paucity of cases in some highly exposed groups such as poultry cullers, are consistent with a host genetic effect. Animal models support the biological plausibility of genetic susceptibility to A/H5N1. Although the evidence is circumstantial, host genetic factors are a parsimonious explanation for the unusual epidemiology of human A/H5N1 cases and warrant further investigation.

Moïsi JC, Gatakaa H, Noor AM, Williams TN, Bauni E, Tsofa B, Levine OS, Scott JAG. 2010. Geographic access to care is not a determinant of child mortality in a rural Kenyan setting with high health facility density. BMC Public Health, 10 (1), pp. 142. | Citations: 27 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Policy-makers evaluating country progress towards the Millennium Development Goals also examine trends in health inequities. Distance to health facilities is a known determinant of health care utilization and may drive inequalities in health outcomes; we aimed to investigate its effects on childhood mortality. METHODS: The Epidemiological and Demographic Surveillance System in Kilifi District, Kenya, collects data on vital events and migrations in a population of 220,000 people. We used Geographic Information Systems to estimate pedestrian and vehicular travel times to hospitals and vaccine clinics and developed proportional-hazards models to evaluate the effects of travel time on mortality hazard in children less than 5 years of age, accounting for sex, ethnic group, maternal education, migrant status, rainfall and calendar time. RESULTS: In 2004-6, under-5 and under-1 mortality ratios were 65 and 46 per 1,000 live-births, respectively. Median pedestrian and vehicular travel times to hospital were 193 min (inter-quartile range: 125-267) and 49 min (32-72); analogous values for vaccine clinics were 47 (25-73) and 26 min (13-40). Infant and under-5 mortality varied two-fold across geographic locations, ranging from 34.5 to 61.9 per 1000 child-years and 8.8 to 18.1 per 1000, respectively. However, distance to health facilities was not associated with mortality. Hazard Ratios (HR) were 0.99 (95% CI 0.95-1.04) per hour and 1.01 (95% CI 0.95-1.08) per half-hour of pedestrian and vehicular travel to hospital, respectively, and 1.00 (95% CI 0.99-1.04) and 0.97 (95% CI 0.92-1.05) per quarter-hour of pedestrian and vehicular travel to vaccine clinics in children <5 years of age. CONCLUSIONS: Significant spatial variations in mortality were observed across the area, but were not correlated with distance to health facilities. We conclude that given the present density of health facilities in Kenya, geographic access to curative services does not influence population-level mortality.

Mwaniki M, Mathenge A, Gwer S, Mturi N, Bauni E, Newton CRJC, Berkley J, Idro R. 2010. Neonatal seizures in a rural Kenyan District Hospital: aetiology, incidence and outcome of hospitalization. BMC Med, 8 (1), pp. 16. | Citations: 12 (Scopus) | Show Abstract | Read more

BACKGROUND: Acute seizures are common among children admitted to hospitals in resource poor countries. However, there is little data on the burden, causes and outcome of neonatal seizures in sub-Saharan Africa. We determined the minimum incidence, aetiology and immediate outcome of seizures among neonates admitted to a rural district hospital in Kenya. METHODS: From 1st January 2003 to 31st December 2007, we assessed for seizures all neonates (age 0-28 days) admitted to the Kilifi District Hospital, who were resident in a defined, regularly enumerated study area. The population denominator, the number of live births in the community on 1 July 2005 (the study midpoint) was modelled from the census data. RESULTS: Seizures were reported in 142/1572 (9.0%) of neonatal admissions. The incidence was 39.5 [95% confidence interval (CI) 26.4-56.7] per 1000 live-births and incidence increased with birth weight. The main diagnoses in neonates with seizures were sepsis in 85 (60%), neonatal encephalopathy in 30 (21%) and meningitis in 21 (15%), but only neonatal encephalopathy and bacterial meningitis were independently associated with seizures. Neonates with seizures had a longer hospitalization [median period 7 days - interquartile range (IQR) 4 to10] -compared to 5 days [IQR 3 to 8] for those without seizures, P = 0.02). Overall, there was no difference in inpatient case fatality between neonates with and without seizures but, when this outcome was stratified by birth weight, it was significantly higher in neonates >or= 2.5 kg compared to low birth weight neonates [odds ratio 1.59 (95%CI 1.02 to 2.46), P = 0.037]. Up to 13% of the surviving newborn with seizures had neurological abnormalities at discharge. CONCLUSION: There is a high incidence of neonatal seizures in this area of Kenya and the most important causes are neonatal encephalopathy and meningitis. The high incidence of neonatal seizures may be a reflection of the quality of the perinatal and postnatal care available to the neonates.

Wiersinga WJ, Kager LM, Hovius JWR, van der Windt GJW, de Vos AF, Meijers JCM, Roelofs JJ, Dondorp A, Levi M, Day NP et al. 2010. Urokinase receptor is necessary for bacterial defense against pneumonia-derived septic melioidosis by facilitating phagocytosis. J Immunol, 184 (6), pp. 3079-3086. | Citations: 39 (Scopus) | Show Abstract | Read more

Urokinase receptor (urokinase-type plasminogen activator receptor [uPAR], CD87), a GPI-anchored protein, is considered to play an important role in inflammation and fibrinolysis. The Gram-negative bacterium Burkholderia pseudomallei is able to survive and replicate within leukocytes and causes melioidosis, an important cause of pneumonia-derived community-acquired sepsis in Southeast Asia. In this study, we investigated the expression and function of uPAR both in patients with septic melioidosis and in a murine model of experimental melioidosis. uPAR mRNA and surface expression was increased in patients with septic melioidosis in/on both peripheral blood monocytes and granulocytes as well as in the pulmonary compartment during experimental pneumonia-derived melioidosis in mice. uPAR-deficient mice intranasally infected with B. pseudomallei showed an enhanced growth and dissemination of B. pseudomallei when compared with wild-type mice, corresponding with increased pulmonary and hepatic inflammation. uPAR knockout mice demonstrated significantly reduced neutrophil migration toward the pulmonary compartment after inoculation with B. pseudomallei. Further in vitro experiments showed that uPAR-deficient macrophages and granulocytes display a markedly impaired phagocytosis of B. pseudomallei. Additional studies showed that uPAR deficiency did not influence hemostatic and fibrinolytic responses during severe melioidosis. These data suggest that uPAR is crucially involved in the host defense against sepsis caused by B. pseudomallei by facilitating the migration of neutrophils toward the primary site of infection and subsequently facilitating the phagocytosis of B. pseudomallei.

Olotu AI, Fegan G, Bejon P. 2010. Further analysis of correlates of protection from a phase 2a trial of the falciparum malaria vaccines RTS,S/AS01B and RTS,S/AS02A in malaria-naive adults. J Infect Dis, 201 (6), pp. 970-971. | Citations: 18 (Scopus) | Read more

Neuhaus J, Angus B, Kowalska JD, La Rosa A, Sampson J, Wentworth D, Mocroft A, INSIGHT SMART and ESPRIT study groups. 2010. Risk of all-cause mortality associated with nonfatal AIDS and serious non-AIDS events among adults infected with HIV. AIDS, 24 (5), pp. 697-706. | Citations: 111 (Scopus) | Show Abstract | Read more

OBJECTIVES: Among patients with HIV, the risk of death associated with different AIDS events has been quantified, but the risk of death associated with non-AIDS events has not been examined. We compared the risk of all-cause mortality following AIDS versus serious non-AIDS (SNA) events in the Strategies for Management of Antiretroviral Therapy (SMART) study and the Evaluation of Subcutaneous Proleukin in a Randomized International Trial (ESPRIT). DESIGN: Data from 9583 HIV-infected participants, 5472 with a CD4 cell count more than 350 cells/microl enrolled in SMART and 4111 with a CD4 cell count 300 cells/microl or more enrolled in ESPRIT, were analyzed. METHODS: Cumulative mortality 6 months after AIDS and SNA events (cardiovascular, renal, hepatic disease, and malignancies) was estimated using the Kaplan-Meier method. Cox models were used to estimate hazard ratios associated with AIDS and SNA events on the risk of death overall and by treatment group within study. RESULTS: AIDS and SNA events occurred in 286 and 435 participants with 47 (16%) and 115 (26%) subsequent deaths, respectively. Six-month cumulative mortality was 4.7% [95% confidence interval (CI) 2.8-8.0] after experiencing an AIDS event and 13.4% (95% CI 10.5-17.0) after experiencing an SNA event. The adjusted hazard ratio for all-cause mortality for those who experienced AIDS versus those who did not was 4.9 (95% CI 3.6-6.8). The corresponding hazard ratio for SNA was 11.4 (95% CI 9.0-14.5) (P < 0.001 for difference in hazard ratios). Findings were similar for both treatment groups in SMART and both treatment groups in ESPRIT. CONCLUSION: Among HIV-infected persons with higher CD4 cell counts, SNA events occur more frequently and are associated with a greater risk of death than AIDS events. Future research should be aimed at comparing strategies to reduce morbidity and mortality associated with SNA events for HIV-infected persons.

Opwora A, Kabare M, Molyneux S, Goodman C. 2010. Direct facility funding as a response to user fee reduction: implementation and perceived impact among Kenyan health centres and dispensaries. Health Policy Plan, 25 (5), pp. 406-418. | Citations: 13 (Scopus) | Show Abstract | Read more

There is increasing pressure for reduction of user fees, but this can have adverse effects by decreasing facility-level funds. To address this, direct facility funding (DFF) was piloted in Coast Province, Kenya, with health facility committees (HFCs) responsible for managing the funds. We evaluated the implementation and perceived impact 2.5 years after DFF introduction. Quantitative data collection at 30 public health centres and dispensaries included a structured interview with the in-charge, record reviews and exit interviews. In addition, in-depth interviews were conducted with the in-charge and HFC members at 12 facilities, and with district staff and other stakeholders. DFF procedures were well established: HFCs met regularly and accounting procedures were broadly followed. DFF made an important contribution to facility cash income, accounting for 47% in health centres and 62% in dispensaries. The main items of expenditure were wages for support staff (32%), travel (21%), and construction and maintenance (18%). DFF was perceived to have a highly positive impact through funding support staff such as cleaners and patient attendants, outreach activities, renovations, patient referrals and increasing HFC activity. This was perceived to have improved health worker motivation, utilization and quality of care. A number of problems were identified. HFC training was reportedly inadequate, and no DFF documentation was available at facility level, leading to confusion. Charging user fees above those specified in the national policy remained common, and understanding of DFF among the broader community was very limited. Finally, relationships between HFCs and health workers were sometimes characterized by mistrust and resentment. Relatively small increases in funding may significantly affect facility performance when the funds are managed at the periphery. Kenya plans to scale up DFF nationwide. Our findings indicate this is warranted, but should include improved training and documentation, greater emphasis on community engagement, and insistence on user fee adherence.

Okara RM, Sinka ME, Minakawa N, Mbogo CM, Hay SI, Snow RW. 2010. Distribution of the main malaria vectors in Kenya. Malar J, 9 (1), pp. 69. | Citations: 23 (Scopus) | Show Abstract | Read more

BACKGROUND: A detailed knowledge of the distribution of the main Anopheles malaria vectors in Kenya should guide national vector control strategies. However, contemporary spatial distributions of the locally dominant Anopheles vectors including Anopheles gambiae, Anopheles arabiensis, Anopheles merus, Anopheles funestus, Anopheles pharoensis and Anopheles nili are lacking. The methods and approaches used to assemble contemporary available data on the present distribution of the dominant malaria vectors in Kenya are presented here. METHOD: Primary empirical data from published and unpublished sources were identified for the period 1990 to 2009. Details recorded for each source included the first author, year of publication, report type, survey location name, month and year of survey, the main Anopheles species reported as present and the sampling and identification methods used. Survey locations were geo-positioned using national digital place name archives and on-line geo-referencing resources. The geo-located species-presence data were displayed and described administratively, using first-level administrative units (province), and biologically, based on the predicted spatial margins of Plasmodium falciparum transmission intensity in Kenya for the year 2009. Each geo-located survey site was assigned an urban or rural classification and attributed an altitude value. RESULTS: A total of 498 spatially unique descriptions of Anopheles vector species across Kenya sampled between 1990 and 2009 were identified, 53% were obtained from published sources and further communications with authors. More than half (54%) of the sites surveyed were investigated since 2005. A total of 174 sites reported the presence of An. gambiae complex without identification of sibling species. Anopheles arabiensis and An. funestus were the most widely reported at 244 and 265 spatially unique sites respectively with the former showing the most ubiquitous distribution nationally. Anopheles gambiae, An. arabiensis, An. funestus and An. pharoensis were reported at sites located in all the transmission intensity classes with more reports of An. gambiae in the highest transmission intensity areas than the very low transmission areas. CONCLUSION: A contemporary, spatially defined database of the main malaria vectors in Kenya provides a baseline for future compilations of data and helps identify areas where information is currently lacking. The data collated here are published alongside this paper where it may help guide future sampling location decisions, help with the planning of vector control suites nationally and encourage broader research inquiry into vector species niche modeling.

Choowongkomon K, Theppabutr S, Songtawee N, Day NPJ, White NJ, Woodrow CJ, Imwong M. 2010. Computational analysis of binding between malarial dihydrofolate reductases and anti-folates. Malar J, 9 (1), pp. 65. | Citations: 5 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Plasmodium falciparum readily develops resistance to the anti-folates pyrimethamine and proguanil via a characteristic set of mutations in the dihydrofolate reductase (PfDHFR) gene that leads to reduced competitive drug binding at the enzyme's active site. Analogous mutations can be found in the DHFR gene in isolates of Plasmodium vivax (PvDHFR) although anti-folates have not been widely used for the treatment of this infection. Here the interactions between DHFR inhibitors and modelled structures of the DHFR enzymes of Plasmodium malariae (PmDHFR) and Plasmodium ovale (PoDHFR) are described, along with an investigation of the effect of recently reported mutations within PmDHFR. METHODS: DHFR models for PmDHFR and PoDHFR were constructed using the solved PfDHFR-TS and PvDHFR structures respectively as templates. The modelled structures were docked with three DHFR inhibitors as ligands and more detailed interactions were explored via simulation of molecular dynamics. RESULTS: Highly accurate models were obtained containing sets of residues that mediate ligand binding which are highly comparable to those mediating binding in known crystal structures. Within this set, there were differences in the relative contribution of individual residues to inhibitor binding. Modelling of PmDHFR mutant sequences revealed that PmDHFR I170M was associated with a significant reduction in binding energy to all DHFR inhibitors studied, while the other predicted resistance mutations had lesser or no effects on ligand binding. CONCLUSIONS: Binding of DHFR inhibitors to the active sites of all four Plasmodium enzymes is broadly similar, being determined by an analogous set of seven residues. PmDHFR mutations found in field isolates influenced inhibitor interactions to a varying extent. In the case of the isolated I170M mutation, the loss of interaction with pyrimethamine suggests that DHFR-inhibitor interactions in P. malariae are different to those seen for DHFRs from P. falciparum and P. vivax.

Bousema T, Youssef RM, Cook J, Cox J, Alegana VA, Amran J, Noor AM, Snow RW, Drakeley C. 2010. Serologic markers for detecting malaria in areas of low endemicity, Somalia, 2008. Emerg Infect Dis, 16 (3), pp. 392-399. | Citations: 86 (Scopus) | Show Abstract | Read more

Areas in which malaria is not highly endemic are suitable for malaria elimination, but assessing transmission is difficult because of lack of sensitivity of commonly used methods. We evaluated serologic markers for detecting variation in malaria exposure in Somalia. Plasmodium falciparum or P. vivax was not detected by microscopy in cross-sectional surveys of samples from persons during the dry (0/1,178) and wet (0/1,128) seasons. Antibody responses against P. falciparum or P. vivax were detected in 17.9% (179/1,001) and 19.3% (202/1,044) of persons tested. Reactivity against P. falciparum was significantly different between 3 villages (p<0.001); clusters of seroreactivity were present. Distance to the nearest seasonal river was negatively associated with P. falciparum (p = 0.028) and P. vivax seroreactivity (p = 0.016). Serologic markers are a promising tool for detecting spatial variation in malaria exposure and evaluating malaria control efforts in areas where transmission has decreased to levels below the detection limit of microscopy.

Koh GCKW, Maude RJ, Paris DH, Newton PN, Blacksell SD. 2010. Diagnosis of scrub typhus. Am J Trop Med Hyg, 82 (3), pp. 368-370. | Citations: 87 (Web of Science Lite) | Show Abstract | Read more

Scrub typhus is transmitted by trombiculid mites and is endemic to East and Southeast Asia and Northern Australia. The clinical syndrome classically consists of a fever, rash, and eschar, but scrub typhus also commonly presents as an undifferentiated fever that requires laboratory confirmation of the diagnosis, usually by indirect fluorescent antibody (IFA) assay. We discuss the limitations of IFA, debate the value of other methods based on antigen detection and nucleic acid amplification, and outline recommendations for future study.

Mu J, Myers RA, Jiang H, Liu S, Ricklefs S, Waisberg M, Chotivanich K, Wilairatana P, Krudsood S, White NJ et al. 2010. Plasmodium falciparum genome-wide scans for positive selection, recombination hot spots and resistance to antimalarial drugs. Nat Genet, 42 (3), pp. 268-271. | Citations: 126 (Scopus) | Show Abstract | Read more

Antimalarial drugs impose strong selective pressure on Plasmodium falciparum parasites and leave signatures of selection in the parasite genome; screening for genes under selection may suggest potential drug or immune targets. Genome-wide association studies (GWAS) of parasite traits have been hampered by the lack of high-throughput genotyping methods, inadequate knowledge of parasite population history and time-consuming adaptations of parasites to in vitro culture. Here we report the first Plasmodium GWAS, which included 189 culture-adapted P. falciparum parasites genotyped using a custom-built Affymetrix molecular inversion probe 3K malaria panel array with a coverage of approximately 1 SNP per 7 kb. Population structure, variation in recombination rate and loci under recent positive selection were detected. Parasite half-maximum inhibitory concentrations for seven antimalarial drugs were obtained and used in GWAS to identify genes associated with drug responses. This study provides valuable tools and insight into the P. falciparum genome.

Molyneux S, Kamuya D, Marsh V. 2010. Community members employed on research projects face crucial, often under-recognized, ethical dilemmas. Am J Bioeth, 10 (3), pp. 24-26. | Citations: 13 (Web of Science Lite) | Read more

Wells TNC, Burrows JN, Baird JK. 2010. Targeting the hypnozoite reservoir of Plasmodium vivax: the hidden obstacle to malaria elimination. Trends Parasitol, 26 (3), pp. 145-151. | Citations: 156 (Scopus) | Show Abstract | Read more

Plasmodium vivax is the major species of malaria parasite outside Africa. It is especially problematic in that the infection can relapse in the absence of mosquitoes by activation of dormant hypnozoites in the liver. Medicines that target the erythrocytic stages of Plasmodium falciparum are also active against P. vivax, except where these have been compromised by resistance. However, the only clinical therapy against relapse of vivax malaria is the 8-aminoquinoline, primaquine. This molecule has the drawback of causing haemolysis in genetically sensitive patients and requires 14 days of treatment. New, safer and more-easily administered drugs are urgently needed, and this is a crucial gap in the broader malaria-elimination agenda. New developments in cell biology are starting to open ways to the next generation of drugs against hypnozoites. This search is urgent, given the time needed to develop a new medication.

Nzila A, Okombo J, Becker RP, Chilengi R, Lang T, Niehues T. 2010. Anticancer agents against malaria: time to revisit? Trends Parasitol, 26 (3), pp. 125-129. | Citations: 25 (Scopus) | Show Abstract | Read more

The emergence of artemisinin resistance could adversely impact the current strategy for malaria treatment; thus, new drugs are urgently needed. A possible approach to developing new antimalarials is to find new uses for old drugs. Some anticancer agents such as methotrexate and trimetrexate are active against malaria. However, they are commonly perceived to be toxic and thus not suitable for malaria treatment. In this opinion article, we examine how the toxicity of anticancer agents is just a matter of dose or 'only dose makes the poison', as coined in Paracelsus' law. Thus, the opportunity exists to discover new antimalarials using the anticancer pharmacopoeia.

Ahmed N, Pinkham M, Warrell DA, Verdez J-M. 2010. Symptom in search of a toxin: muscle spasms following bites by Old World tarantula spiders (Lampropelma nigerrimum, Pterinochilus murinus, Poecilotheria regalis) with review (vol 102, pg 851, 2009) QJM-AN INTERNATIONAL JOURNAL OF MEDICINE, 103 (3), pp. 203-204. | Citations: 1 (Web of Science Lite) | Read more

Wertheim HF, Horby P, Viet TL, Tanh TNT, Woodall J. 2010. The making of a world atlas of infectious diseases INTERNATIONAL JOURNAL OF INFECTIOUS DISEASES, 14 pp. E282-E283. | Read more

Osier FHA, Murungi LM, Fegan G, Tuju J, Tetteh KK, Bull PC, Conway DJ, Marsh K. 2010. Allele-specific antibodies to Plasmodium falciparum merozoite surface protein-2 and protection against clinical malaria. Parasite Immunol, 32 (3), pp. 193-201. | Citations: 17 (Web of Science Lite) | Show Abstract | Read more

IgG and IgG3 antibodies to merozoite surface protein-2 (MSP-2) of Plasmodium falciparum have been associated with protection from clinical malaria in independent studies. We determined whether this protection was allele-specific by testing whether children who developed clinical malaria lacked IgG/IgG3 antibodies specific to the dominant msp2 parasite genotypes detected during clinical episodes. We analysed pre-existing IgG and IgG1/IgG3 antibodies to antigens representing the major dimorphic types of MSP-2 by ELISA. We used quantitative real-time PCR to determine the dominant msp2 alleles in parasites detected in clinical episodes. Over half (55%, 80/146) of infections contained both allelic types. Single or dominant IC1- and FC27-like alleles were detected in 46% and 42% of infections respectively, and both types were equally dominant in 12%. High levels of IgG/IgG3 antibodies to the FC27-like antigen were not significantly associated with a lower likelihood of clinical episodes caused by parasites bearing FC27-like compared to IC1-like alleles, and vice versa for IgG/IgG3 antibodies to the IC1-like antigen. These findings were supported by competition ELISAs which demonstrated the presence of IgG antibodies to allele-specific epitopes within both antigens. Thus, even for this well-studied antigen, the importance of an allele-specific component of naturally acquired protective immunity to malaria remains to be confirmed.

van Dommelen L, Verbon A, van Doorn HR, Goossens VJ. 2010. Acute hepatitis B virus infection with simultaneous high HBsAg and high anti-HBs signals in a previously HBV vaccinated HIV-1 positive patient. J Clin Virol, 47 (3), pp. 293-296. | Citations: 4 (Scopus) | Show Abstract | Read more

We present a case of a clinical manifest hepatitis B virus infection and a potentially misleading HBV serological profile in an HIV-1 positive patient despite previous HBV vaccination. The patient presented with an acute hepatitis B and there was no indication of chronic HBV infection or the presence of a mutation in the 'a' determinant. Remarkably, simultaneously with high HBV surface antigen and HBV viral load, high anti-HBs antibodies were present. If, due to previous HBV vaccination only anti-HBs was tested in this patient, the result of the high anti-HBs antibodies could be very misleading and offering a false sense of security. Our findings contribute to the ongoing discussion on how to assess HBV specific immunological memory and determining the role of HBV booster vaccinations in immunocompromised individuals.

White LJ, Schukken YH, Dogan B, Green L, Döpfer D, Chappell MJ, Medley GF. 2010. Modelling the dynamics of intramammary E. coli infections in dairy cows: understanding mechanisms that distinguish transient from persistent infections. Vet Res, 41 (2), pp. 13. | Citations: 15 (Web of Science Lite) | Show Abstract | Read more

The majority of intramammary infections with Escherichia coli in dairy cows result in transient infections with duration of about 10 days or less, although more persistent infections (2 months or longer) have been identified. We apply a mathematical model to explore the role of an intracellular mammary epithelial cell reservoir in the dynamics of infection. We included biological knowledge of the bovine immune response and known characteristics of the bacterial population in both transient and persistent infections. The results indicate that varying the survival duration of the intracellular reservoir reproduces the data for both transient and persistent infections. Survival in an intracellular reservoir is the most likely mechanism that ensures persistence of E. coli infections in mammary glands. Knowledge of the pathogenesis of persistent infections is essential to develop preventive and treatment programmes for these important infections in dairy cows.

Vongphrachanh P, Simmerman JM, Phonekeo D, Pansayavong V, Sisouk T, Ongkhamme S, Bryce GT, Corwin A, Bryant JE. 2010. An early report from newly established laboratory-based influenza surveillance in Lao PDR. Influenza Other Respir Viruses, 4 (2), pp. 47-52. | Citations: 22 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Prior to 2007, little information was available about the burden of influenza in Laos. We report data from the first laboratory-based influenza surveillance system established in the Lao People's Democratic Republic. METHODS: Three hospitals in the capital city of Vientiane began surveillance for influenza-like illness (ILI) in outpatients in 2007 and expanded to include hospitalized pneumonia patients in 2008. Nasal/throat swab specimens were collected and tested for influenza and other respiratory viruses by multiplex ID-Tag respiratory viral panel (RVP) assay on a Luminex 100x MAP IS instrument (Qiagen, Singapore). RESULTS: During January 2007 to December 2008, 287 of 526 (54.6%) outpatients with ILI were positive for at least one respiratory virus. Influenza was most commonly identified, with 63 (12.0%) influenza A and 92 (17.5%) influenza B positive patients identified. In 2008, six of 79 (7.6%) hospitalized pneumonia patients were positive for influenza A and four (5.1%) were positive for influenza B. Children <5 years represented 19% of viral infections in outpatients and 38% of pneumonia inpatients. CONCLUSION: Our results provide the first documentation of influenza burden among patients with febrile respiratory illness and pneumonia requiring hospitalization in Laos. Implementing laboratory-based influenza surveillance requires substantial investments in infrastructure and training. However, continuing outbreaks of avian influenza A/H5N1 in poultry and emergence of the 2009 influenza A(H1N1) pandemic strain further underscore the importance of establishing and maintaining influenza surveillance in developing countries.

Bejon P, Berendt A, Atkins BL, Green N, Parry H, Masters S, McLardy-Smith P, Gundle R, Byren I. 2010. Two-stage revision for prosthetic joint infection: predictors of outcome and the role of reimplantation microbiology. J Antimicrob Chemother, 65 (3), pp. 569-575. | Citations: 70 (Scopus) | Show Abstract | Read more

OBJECTIVES: We describe rates of success for two-stage revision of prosthetic joint infection (PJI), including data on reimplantation microbiology. METHODS: We retrospectively collected data from all the cases of PJI that were managed with two-stage revision over a 4 year period. Patients were managed with an antibiotic-free period before reimplantation, in order to confirm, clinically and microbiologically, that infection was successfully treated. RESULTS: One hundred and fifty-two cases were identified. The overall success rate (i.e. retention of the prosthesis over 5.75 years of follow-up) was 83%, but was 89% for first revisions and 73% for re-revisions [hazard ratio = 2.9, 95% confidence interval (CI) 1.2-7.4, P = 0.023]. Reimplantation microbiology was frequently positive (14%), but did not predict outcome (hazard ratio = 1.3, 95% CI 0.4-3.7, P = 0.6). Furthermore, most unplanned debridements following the first stage were carried out before antibiotics were stopped (25 versus 2 debridements). CONCLUSIONS: We did not identify evidence supporting the use of an antibiotic-free period before reimplantation and routine reimplantation microbiology. Re-revision was associated with a significantly worse outcome.

Choi SY, Lee JH, Kim EJ, Lee HR, Jeon Y-S, von Seidlein L, Deen J, Ansaruzzaman M, Lucas GMES, Barreto A et al. 2010. Classical RS1 and environmental RS1 elements in Vibrio cholerae O1 El Tor strains harbouring a tandem repeat of CTX prophage: revisiting Mozambique in 2005. J Med Microbiol, 59 (Pt 3), pp. 302-308. | Citations: 13 (Scopus) | Show Abstract | Read more

Currently, Vibrio cholerae O1 serogroup biotype El Tor strains producing classical type cholera toxin (altered strains or El Tor variants) are prevalent in Asia and in Mozambique. Mozambican strains collected in 2004 contained a tandem repeat of CTX prophage on the small chromosome and each CTX prophage harboured the classical rstR and classical ctxB. We found that the majority of the strains collected in 2005 in Mozambique contained extra elements on the large chromosome in addition to the tandem repeat of CTX prophage on the small chromosome. New type RS1 elements RS1(cla) and RS1(env), and a CTX(env) with rstR(env) and the classical ctxB were identified on the large chromosome of the Mozambican isolates collected in 2005.

Barta Z, Harrison MJ, Wangrangsimakul T, Shelmerdine J, Teh L-S, Pattrick M, Edlin H, Dale N, Ahmad Y, Bruce IN. 2010. Health-related quality of life, smoking and carotid atherosclerosis in white British women with systemic lupus erythematosus. Lupus, 19 (3), pp. 231-238. | Citations: 11 (Scopus) | Show Abstract | Read more

We tested the hypothesis that carotid atherosclerosis in systemic lupus erythematosus (SLE) is associated with poor health-related quality of life (HRQOL), which is independent of any association with traditional risk factors (TRFs), lifestyle and socioeconomic factors. Women with SLE completed the RAND Medical Outcome Study 36-Item Short-Form Health Survey version 1 (MOS SF-36). B-mode Doppler examination of the carotid arteries determined the presence of atherosclerotic plaque. The association between carotid plaque and HRQOL domains was analysed using logistic regression models with sequential adjustments for age, TRFs, education level and employment status. We studied 181 women, 47 (26%) of whom had carotid plaque. Carotid plaque was significantly associated with lower levels of physical functioning (p = 0.047), vitality (p = 0.04), role emotional (p = 0.04) and mental health subscales (p = 0.01) and lower mental component summary score (MCS) (p = 0.03). These associations were no longer significant after adjustment for age and TRFs, especially smoking. Smokers had lower physical functioning, vitality and mental health and more bodily pain. The association between carotid plaque and HRQOL was not independent of TRFs and smoking was a key mediator of the associations found. Poor HRQOL in smokers will need addressing as part of any smoking cessation strategies in SLE patients.

Gregory A, Ramsay J, Agnew-Davies R, Baird K, Devine A, Dunne D, Eldridge S, Howell A, Johnson M, Rutterford C et al. 2010. Primary care identification and referral to improve safety of women experiencing domestic violence (IRIS): protocol for a pragmatic cluster randomised controlled trial. BMC Public Health, 10 (1), pp. 54. | Citations: 7 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Domestic violence, which may be psychological, physical, sexual, financial or emotional, is a major public health problem due to the long-term health consequences for women who have experienced it and for their children who witness it. In populations of women attending general practice, the prevalence of physical or sexual abuse in the past year from a partner or ex-partner ranges from 6 to 23%, and lifetime prevalence from 21 to 55%. Domestic violence is particularly important in general practice because women have many contacts with primary care clinicians and because women experiencing abuse identify doctors and nurses as professionals from whom they would like to get support. Yet health professionals rarely ask about domestic violence and have little or no training in how to respond to disclosure of abuse. METHODS/DESIGN: This protocol describes IRIS, a pragmatic cluster randomised controlled trial with the general practice as unit of randomisation. Our trial tests the effectiveness and cost-effectiveness of a training and support programme targeted at general practice teams. The primary outcome is referral of women to specialist domestic violence agencies. Forty-eight practices in two UK cities (Bristol and London) are randomly allocated, using minimisation, into intervention and control groups. The intervention, based on an adult learning model in an educational outreach framework, has been designed to address barriers to asking women about domestic violence and to encourage appropriate responses to disclosure and referral to specialist domestic violence agencies. Multidisciplinary training sessions are held with clinicians and administrative staff in each of the intervention practices, with periodic feedback of identification and referral data to practice teams. Intervention practices have a prompt to ask about abuse integrated in the electronic medical record system. Other components of the intervention include an IRIS champion in each practice and a direct referral pathway to a named domestic violence advocate. DISCUSSION: This is the first European randomised controlled trial of an intervention to improve the health care response to domestic violence. The findings will have the potential to inform training and service provision. TRIAL REGISTRATION: ISRCTN74012786.

Baumeister S, Winterberg M, Przyborski JM, Lingelbach K. 2010. The malaria parasite Plasmodium falciparum: cell biological peculiarities and nutritional consequences. Protoplasma, 240 (1-4), pp. 3-12. | Citations: 13 (Scopus) | Show Abstract | Read more

Apicomplexan parasites obligatorily invade and multiply within eukaryotic cells. Phylogenetically, they are related to a group of algae which, during their evolution, have acquired a secondary endosymbiont. This organelle, which in the parasite is called the apicoplast, is highly reduced compared to the endosymbionts of algae, but still contains many plant-specific biosynthetic pathways. The malaria parasite Plasmodium falciparum infects mammalian erythrocytes which are devoid of intracellular compartments and which largely lack biosynthetic pathways. Despite the limited resources of nutrition, the parasite grows and generates up to 32 merozoites which are the infectious stages of the complex life cycle. A large part of the intra-erythrocytic development takes place in the so-called parasitophorous vacuole, a compartment which forms an interface between the parasite and the cytoplasm of the host cell. In the course of parasite growth, the host cell undergoes dramatic alterations which on one hand contribute directly to the symptoms of severe malaria and which, on the other hand, are also required for parasite survival. Some of these alterations facilitate the acquisition of nutrients from the extracellular environment which are not provided by the host cell. Here, we describe the cell biologically unique interactions between an intracellular eukaryotic pathogen and its metabolically highly reduced host cell. We further discuss current models to explain the appearance of pathogen-induced novel physiological properties in a host cell which has lost its genetic programme.

van der Wal WM, Noordzij M, Dekker FW, Boeschoten EW, Krediet RT, Korevaar JC, Geskus RB. 2010. Comparing mortality in renal patients on hemodialysis versus peritoneal dialysis using a marginal structural model. Int J Biostat, 6 (1), pp. Article-2. | Citations: 17 (Scopus) | Show Abstract | Read more

When comparing the causal effect of peritoneal dialysis (PD) and hemodialysis (HD) treatment on lowering mortality in renal patients, using observational data, it is necessary to adjust for different forms of confounding and informative censoring. Both the type of dialysis treatment that is started with and mortality are affected by baseline covariates. Longitudinal and baseline variables can affect both the probability of switching from one type of dialysis to the other, and mortality. Longitudinal and baseline variables can also affect the probability of receiving a kidney transplant, possibly causing informative censoring. Adjusting for longitudinal variables by including them as covariates in a regression model potentially causes bias, for instance by losing a possible indirect effect of dialysis on mortality via these longitudinal variables. Instead, we fitted a marginal structural model (MSM) to estimate the causal effect of dialysis type, adjusted for confounding and informative censoring. We used the MSM to compare the hazard of death as well as cumulative survival between the potential treatment trajectories "always PD" and "always HD" over time, conditional on age and diabetes mellitus status. We used inverse probability weighting (IPW) to fit the MSM.

Robinson MT, Morgan ER, Woods D, Shaw SE. 2010. Real-time and multiplex real-time polymerase chain reactions for the detection of Bartonella henselae within cat flea, Ctenocephalides felis, samples. Med Vet Entomol, 24 (4), pp. 449-455. | Show Abstract | Read more

Bartonella henselae (Rhizobiales: Bartonellacae), the agent of cat-scratch disease, is an emerging bacterial pathogen which can be transmitted via infective faecal material of Ctenocephalides felis Bouché (Siphonaptera: Pulicidae). Worldwide, B. henselae has been identified in 1-53% of felines and 2.9-17.4% of fleas. Although culture is the routine method for detection, the procedure is time-consuming and is rarely used for isolation directly from flea vectors. The current study reports the development of a quantitative real-time polymerase chain reaction (qPCR) to detect and quantify B. henselae organisms from vector samples. The qPCR is specific and detects as few as 2.5 genome copies. To enable direct quantification of Bartonella organisms in different vector samples, we developed a qPCR to detect C. felis DNA that also acts as an extraction control. Combining both PCRs into a multiplex format validates B. henselae results when sampling flea populations, although there is a reduction in sensitivity. This reduction might be counteracted by a different combination of probe fluorophores.

Gilmore CP, Elliott I, Auer D, Maddison P. 2010. Diffuse cerebellar MR imaging changes in anti-Yo positive paraneoplastic cerebellar degeneration Journal of Neurology, 257 (3), pp. 490-491. | Read more

Warrell DA. 2010. Snake bite (vol 375, pg 77, 2010) LANCET, 375 (9715), pp. 640-640. | Citations: 2 (Web of Science Lite)

Mtove G, Amos B, von Seidlein L, Hendriksen I, Mwambuli A, Kimera J, Mallahiyo R, Kim DR, Ochiai RL, Clemens JD et al. 2010. Invasive salmonellosis among children admitted to a rural Tanzanian hospital and a comparison with previous studies. PLoS One, 5 (2), pp. e9244. | Citations: 45 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: The importance of invasive salmonellosis in African children is well recognized but there is inadequate information on these infections. We conducted a fever surveillance study in a Tanzanian rural hospital to estimate the case fraction of invasive salmonellosis among pediatric admissions, examine associations with common co-morbidities and describe its clinical features. We compared our main findings with those from previous studies among children in sub-Saharan Africa. METHODOLOGY/PRINCIPAL FINDINGS: From 1 March 2008 to 28 Feb 2009, 1,502 children were enrolled into the study. We collected clinical information and blood for point of care tests, culture, and diagnosis of malaria and HIV. We analyzed the clinical features on admission and outcome by laboratory-confirmed diagnosis. Pathogenic bacteria were isolated from the blood of 156 (10%) children, of which 14 (9%) were S. typhi, 45 (29%) were NTS and 97 (62%) were other pathogenic bacteria. Invasive salmonellosis accounted for 59/156 (38%) bacteremic children. Children with typhoid fever were significantly older and presented with a longer duration of fever. NTS infections were significantly associated with prior antimalarial treatment, malarial complications and with a high risk for death. CONCLUSIONS/SIGNIFICANCE: Invasive salmonellosis, particularly NTS infection, is an important cause of febrile disease among hospitalized children in our rural Tanzanian setting. Previous studies showed considerable variation in the case fraction of S. typhi and NTS infections. Certain suggestive clinical features (such as older age and long duration of fever for typhoid whereas concomitant malaria, anemia, jaundice and hypoglycemia for NTS infection) may be used to distinguish invasive salmonellosis from other severe febrile illness.

Stepniewska K, Ashley E, Lee SJ, Anstey N, Barnes KI, Binh TQ, D'Alessandro U, Day NPJ, de Vries PJ, Dorsey G et al. 2010. In vivo parasitological measures of artemisinin susceptibility. J Infect Dis, 201 (4), pp. 570-579. | Citations: 99 (Scopus) | Show Abstract | Read more

Parasite clearance data from 18,699 patients with falciparum malaria treated with an artemisinin derivative in areas of low (n=14,539), moderate (n=2077), and high (n=2083) levels of malaria transmission across the world were analyzed to determine the factors that affect clearance rates and identify a simple in vivo screening measure for artemisinin resistance. The main factor affecting parasite clearance time was parasite density on admission. Clearance rates were faster in high-transmission settings and with more effective partner drugs in artemisinin-based combination treatments (ACTs). The result of the malaria blood smear on day 3 (72 h) was a good predictor of subsequent treatment failure and provides a simple screening measure for artemisinin resistance. Artemisinin resistance is highly unlikely if the proportion of patients with parasite densities of <100,000 parasites/microL given the currently recommended 3-day ACT who have a positive smear result on day 3 is <3%; that is, for n patients the observed number with a positive smear result on day 3 does not exceed (n + 60)/24.

Sutanto I, Endawati D, Ling LH, Laihad F, Setiabudy R, Baird JK. 2010. Evaluation of chloroquine therapy for vivax and falciparum malaria in southern Sumatra, western Indonesia. Malar J, 9 (1), pp. 52. | Citations: 21 (Scopus) | Show Abstract | Read more

BACKGROUND: Chloroquine was used as first-line treatment for Plasmodium falciparum or Plasmodium vivax in Indonesia before the initial launch of artemisinin combination therapy in 2004. A study to evaluate efficacies of chloroquine against P. falciparum and P. vivax was undertaken at Lampung in southern Sumatra, western Indonesia in 2002. METHODS: Patients infected by P. falciparum or P. vivax were treated with 25 mg/kg chloroquine base in three daily doses over 48 hr. Finger prick blood was collected on Days 0, 2, 3, 7, 14, 21 and 28 after starting drug administration. Whole blood chloroquine and its desethyl metabolite were measured on Days-0, -3 and -28, or on the day of recurrent parasitaemia. RESULTS: 42 patients infected by P. falciparum were enrolled, and 38 fullfilled criteria for per protocol analysis. Only six of 38 (16%) showed a response consistent with senstivity to chloroquine. 25 of 32 failures were confirmed resistant by demonstrating chloroquine levels on day of recurrence exceeding the minimally effective concentration (200 ng/mL whole blood). The 28-day cumulative incidence of resistance in P. falciparum was 68% (95% CI: 0.5260 - 0.8306). Thirty one patients infected by P. vivax were enrolled, and 23 were evaluable for per protocol analysis. 15 out of 23 (65%) subjects had persistent or recurrent parasitaemia. Measurement of chloroquine levels confirmed all treatment failures prior to Day-15 as resistant. Beyond Day-15, 4 of 7 recurrences also had drug levels above 100 ng/mL and were classified as resistant. The 28-day cumulative incidence of chloroquine resistance in P. vivax was 43% (95% CI: 0.2715 - 0.6384). CONCLUSION: These findings confirm persistantly high levels of resistance to chloroquine by P. falciparum in southern Sumatra, and suggest that high-grade and frequent resistance to chloroquine by P. vivax may be spreading westward in the Indonesia archipelago.

Revell AD, Wang D, Harrigan R, Hamers RL, Wensing AMJ, Dewolf F, Nelson M, Geretti A-M, Larder BA. 2010. Modelling response to HIV therapy without a genotype: an argument for viral load monitoring in resource-limited settings. J Antimicrob Chemother, 65 (4), pp. 605-607. | Citations: 19 (Scopus) | Show Abstract | Read more

In the absence of widespread access to individualized laboratory monitoring, which forms an integral part of HIV patient management in resource-rich settings, the roll-out of highly active antiretroviral therapy (HAART) in resource-limited settings has adopted a public health approach based on standard HAART protocols and clinical/immunological definitions of therapy failure. The cost-effectiveness of HIV-1 viral load monitoring at the individual level in such settings has been debated, and questions remain over the long-term and population-level impact of managing HAART without it. Computational models that accurately predict virological response to HAART using baseline data including CD4 count, viral load and genotypic resistance profile, as developed by the Resistance Database Initiative, have significant potential as an aid to treatment selection and optimization. Recently developed models have shown good predictive performance without the need for genotypic data, with viral load emerging as by far the most important variable. This finding provides further, indirect support for the use of viral load monitoring for the long-term optimization of HAART in resource-limited settings.

Williams TN, Uyoga S, Macharia A, Sharif SK, Scott JA. 2010. Preventable deaths in sickle-cell anaemia in African children Reply LANCET, 375 (9713), pp. 461-461. | Citations: 1 (Scopus) | Read more

McGready R, Nosten F. 2010. Which Drug is Effective and Safe for Acute Malaria in Pregnancy? Reviewing the Evidence DRUG DEVELOPMENT RESEARCH, 71 (1), pp. 56-68. | Citations: 4 (Web of Science Lite) | Show Abstract | Read more

During pregnancy, a woman living or travelling in a malaria endemic area is more at risk of contracting the disease and developing a severe infection and dying than a non-pregnant woman. Despite this increased morbidity and mortality in pregnancy, there are almost no studies on which to base recommendations on the use of antimalarial drugs in this vulnerable group. This is because, paradoxically, the emphasis is often put on the safety of the unborn child rather than that of the infested mother. As a result of this neglect, tens of thousands of pregnant women (and their fetuses) are dying every year of a very preventable and treatable infection. In recent years, some trials have been conducted, especially in areas of high resistance in Plasmodium falciparum in South East Asia. The results show that quinine plus clindamycin is the treatment of choice in the first trimester, while artemisinin treatment should be used in the second and third trimesters in the treatment of uncomplicated malaria. For severe malaria, parenteral artesunate is the treatment of choice. However these studies have also shown that the pharmacokinetic properties of most antimalarials are altered during gestation and that the doses used in non-pregnant adults are often not adapted to pregnancy. Urgent efforts are required to optimize the treatment of malaria in pregnancy. © 2009 Wiley-Liss, Inc.

Segura A, Villalta M, Herrera M, León G, Harrison R, Durfa N, Nasidi A, Calvete JJ, Theakston RDG, Warrell DA, Gutiérrez JM. 2010. Preclinical assessment of the efficacy of a new antivenom (EchiTAb-Plus-ICP) for the treatment of viper envenoming in sub-Saharan Africa. Toxicon, 55 (2-3), pp. 369-374. | Citations: 37 (Scopus) | Show Abstract | Read more

A preclinical assessment was performed on the neutralizing efficacy of a whole IgG polyspecific antivenom (EchiTAb-Plus-ICP), designed for the treatment of snakebite envenomings in Nigeria. It was generated by immunizing horses with the venoms of Echis ocellatus, Bitis arietans and Naja nigricollis, the most medically important species in Nigeria. Antivenom was tested against the venoms of E. ocellatus, Echis leucogaster, Echis pyramidum leakeyi, B. arietans, Bitis gabonica, Bitis rhinoceros and Bitis nasicornis. The neutralization of the venom toxins responsible for the lethal, hemorrhagic, coagulant and local necrotizing activities was assessed, since these are the most significant effects that characterize envenoming by these species. Echis sp venoms exerted lethal, hemorrhagic, coagulant and necrotizing effects, whereas the Bitis sp venoms tested induced lethality, hemorrhage and necrosis, but were devoid of coagulant activity. The antivenom was effective in the neutralization of all effects tested in all venoms. Highest neutralization was achieved against the venoms of E. ocellatus and B. arietans, and the lowest neutralizing potency was against the venom of B. nasicornis, a species that has a low clinical relevance. It is concluded that EchiTAb-Plus-ICP, whilst specifically designed for Nigeria, has a good preclinical neutralizing profile against homologous and heterologous viperid venoms from other sub-Saharan African locations. It therefore constitutes a promising therapeutic option for the treatment of snakebite envenoming in this region.

van Trijp MJCA, Melles DC, Snijders SV, Wertheim HFL, Verbrugh HA, van Belkum A, van Wamel WJ. 2010. Genotypes, superantigen gene profiles, and presence of exfoliative toxin genes in clinical methicillin-susceptible Staphylococcus aureus isolates. Diagn Microbiol Infect Dis, 66 (2), pp. 222-224. | Citations: 12 (Scopus) | Show Abstract | Read more

We compared genotype and virulence gene profiles for strains from carriers with autologous invasive infection (n = 56), nasal isolates from matched carriers (n = 108), and invasive strains from noncarriers (n = 34). Superantigen gene profiles and presence of exfoliative toxin genes A and D were associated with clonal complex rather than with invasive disease.

Suputtamongkol Y, Pongtavornpinyo W, Lubell Y, Suttinont C, Hoontrakul S, Phimda K, Losuwanaluk K, Suwancharoen D, Silpasakorn S, Chierakul W, Day N. 2010. Strategies for diagnosis and treatment of suspected leptospirosis: a cost-benefit analysis. PLoS Negl Trop Dis, 4 (2), pp. e610. | Citations: 25 (Scopus) | Show Abstract | Read more

BACKGROUND: Symptoms and signs of leptospirosis are non-specific. Several diagnostic tests for leptospirosis are available and in some instances are being used prior to treatment of leptospirosis-suspected patients. There is therefore a need to evaluate the cost-effectiveness of the different treatment strategies in order to avoid misuse of scarce resources and ensure best possible health outcomes for patients. METHODS: The study population was adult patients, presented with uncomplicated acute febrile illness, without an obvious focus of infection or malaria or typical dengue infection. We compared the cost and effectiveness of 5 management strategies: 1) no patients tested or given antibiotic treatment; 2) all patients given empirical doxycycline treatment; patients given doxycycline when a patient is tested positive for leptospirosis using: 3) lateral flow; 4) MCAT; 5) latex test. The framework used is a cost-benefit analysis, accounting for all direct medical costs in diagnosing and treating patients suspected of leptospirosis. Outcomes are measured in length of fever after treatment which is then converted to productivity losses to capture the full economic costs. FINDINGS: Empirical doxycycline treatment was the most efficient strategy, being both the least costly alternative and the one that resulted in the shortest duration of fever. The limited sensitivity of all three diagnostic tests implied that their use to guide treatment was not cost-effective. The most influential parameter driving these results was the cost of treating patients with complications for patients who did not receive adequate treatment as a result of incorrect diagnosis or a strategy of no-antibiotic-treatment. CONCLUSIONS: Clinicians should continue treating suspected cases of leptospirosis on an empirical basis. This conclusion holds true as long as policy makers are not prioritizing the reduction of use of antibiotics, in which case the use of the latex test would be the most efficient strategy.

Tovanabutra S, Sanders EJ, Graham SM, Mwangome M, Peshu N, McClelland RS, Muhaari A, Crossler J, Price MA, Gilmour J et al. 2010. Evaluation of HIV type 1 strains in men having sex with men and in female sex workers in Mombasa, Kenya. AIDS Res Hum Retroviruses, 26 (2), pp. 123-131. | Citations: 20 (Web of Science Lite) | Show Abstract | Read more

We compared HIV-1 strains in incident and prevalent infections in a cohort of men having sex with men (MSM) and female sex workers (FSW) near Mombasa, Kenya and conducted a cross-sectional study of viral isolates from a sample of HIV-1-infected MSM and FSW in Kilifi, Coast Province, Kenya. RNA extracted from plasma of 13 MSM, 9 FSW, and one heterosexual male was amplified by nested RT-PCR and the products were directly sequenced. HIV-1 strains from 21 individuals were characterized with one or more complete genome sequences, and two were sequenced in the Nef gene. The envelope quasispecies was also studied in one individual. Among MSM, eight strains were subtype A and five were recombinant. There were two epidemiologically linked pairs of sequences; one pair was subtype A and the other pair was a complex AA2CD recombinant of identical structure. Another MSM was dually infected with DG recombinant strains of related, but nonidentical, structure. MSM also harbored AC and AD recombinant strains. The FSW harbored seven subtype A strains, an AD recombinant, and an AA2D strain related to CRF16_A2D. The one heterosexual male studied had a subtype A infection. This MSM epidemic in Kenya appears to be of local origin, harboring many strains typical of the broader Kenyan epidemic. Characteristics of a close social network were identified, with extended chains of transmission, novel recombinant strains possibly generated within the network, and a relatively high proportion of recombinant and dual infections.

Wallis CL, Papathanasopoulos MA, Lakhi S, Karita E, Kamali A, Kaleebu P, Sanders E, Anzala O, Bekker L-G, Stevens G et al. 2010. Affordable in-house antiretroviral drug resistance assay with good performance in non-subtype B HIV-1. J Virol Methods, 163 (2), pp. 505-508. | Citations: 35 (Web of Science Lite) | Show Abstract | Read more

The introduction of antiretroviral (ARV) therapy in resource-poor settings is effective in suppressing HIV-1 replication and prolonging life of infected individuals. This has led to a demand for affordable HIV-1 drug resistance assays, since treatment failure due to development of drug resistance is common. This study developed and evaluated an affordable "in-house" genotyping assay to monitor HIV-1 drug resistance in Africa, particularly South Africa. An "in-house" assay using automated RNA extraction, and subtype C specific PCR and sequencing primers was developed and successfully evaluated 396 patient samples (viral load ranges 1000-1.6 million RNA copies/ml). The "in-house" assay was validated by comparing sequence data and drug resistance profiles from 90 patient and 10 external quality control samples to data from the ViroSeq HIV-1 Genotyping kit. The "in-house" assay was more efficient, amplifying all 100 samples, compared to 91 samples using Viroseq. The "in house" sequences were 99.2% homologous to the ViroSeq sequences, and identical drug resistance mutation profiles were observed in 96 samples. Furthermore, the "in-house" assay genotyped 260 of 295 samples from seven African sites, where 47% were non-subtype C. Overall, the newly validated "in-house" drug resistance assay is suited for use in Africa as it overcomes the obstacle of subtype diversity.

Maude RJ, Woodrow CJ, White LJ. 2010. Artemisinin Antimalarials: Preserving the "Magic Bullet" Drug Dev Res, 71 (1), pp. 12-19. | Citations: 32 (Scopus) | Show Abstract | Read more

The artemisinins are the most effective antimalarial drugs known. They possess a remarkably wide therapeutic index. These agents have been used in traditional Chinese herbal medicine for more than 2,000 years but were not subjected to scientific scrutiny until the 1970s. The first formal clinical trials of the artemisinins, and the development of methods for their industrial scale production, followed rapidly. A decade later, Chinese scientists shared their findings with the rest of the world; since then, a significant body of international trial evidence has confirmed these drugs to be far superior to any available alternatives. In particular, they have the ability to rapidly kill a broad range of asexual parasite stages at safe concentrations that are consistently achievable via standard dosing regimens. As their half-life is very short, there was also thought to be a low risk of resistance. These discoveries coincided with the appearance and spread of resistance to all the other major classes of antimalarials. As a result, the artemisinins now form an essential element of recommended first-line antimalarial treatment regimens worldwide. To minimize the risk of artemisinin resistance, they are recommended to be used to treat uncomplicated malaria in combination with other antimalarials as artemisinin combination therapies (ACTs). Their rollout has resulted in documented reductions in malaria prevalence in a number of African and Asian countries. Unfortunately, there are already worrisome early signs of artemisinin resistance appearing in western Cambodia. If this resistance were to spread, it would be disastrous for malaria control efforts worldwide. The enormous challenge for the international community is how to avert this catastrophe and preserve the effectiveness of this antimalarial "magic bullet". Drug Dev Res 71: 12-19, 2010. © 2009 Wiley-Liss, Inc.

Gichora NN, Fatumo SA, Ngara MV, Chelbat N, Ramdayal K, Opap KB, Siwo GH, Adebiyi MO, El Gonnouni A, Zofou D et al. 2010. Ten simple rules for organizing a virtual conference--anywhere. PLoS Comput Biol, 6 (2), pp. e1000650. | Read more

van Houdt R, Bruisten SM, Geskus RB, Bakker M, Wolthers KC, Prins M, Coutinho RA. 2010. Ongoing transmission of a single hepatitis B virus strain among men having sex with men in Amsterdam. J Viral Hepat, 17 (2), pp. 108-114. | Citations: 24 (Scopus) | Show Abstract | Read more

For the past decade, a specific hepatitis B virus (HBV) genotype A strain has been prevalent among men having sex with men (MSM) in Amsterdam, the Netherlands. At what point in time this strain was introduced in the MSM population, and why only this specific strain continues to be transmitted, remains unclear. Between 1984 and 2003, sera of 1862 MSM were retrospectively screened for anti-HBc in the context of the Amsterdam Cohort studies. After 2003, most MSM participating in this study were vaccinated, making further testing less useful. HBV DNA from anti-HBc seroconverters was amplified and sequenced. Poisson regression was used to test for temporal trends in HBV and HIV incidence. Of the 1042 MSM who were negative for anti-HBc at entry, 64 had seroconverted during follow-up at a median age of 32. At the point of seroconversion, 31 MSM were HIV positive. HBV incidence declined dramatically in the first years and then remained stable throughout the study period. The HBV and HIV incidence ran almost in parallel. With the exception of three MSM, all were infected with genotype A. Fifteen of these (41%) were infected with an identical genotype A strain. For the past two decades, an identical genotype A strain has been circulating among MSM in the Netherlands. Although HBV is generally considered more infectious than HIV, this study shows that the trend and magnitude in HBV and HIV incidence among MSM are similar.

Kitua A, Folb P, Warsame M, Binka F, Faiz A, Ribeiro I, Peto T, Gyapong J, Yunus EB, Rahman R et al. 2010. The use of placebo in a trial of rectal artesunate as initial treatment for severe malaria patients en route to referral clinics: ethical issues Journal of Medical Ethics, 36 (2), pp. 116-120. | Read more

Newton PN, Green MD, Fernández FM. 2010. Impact of poor-quality medicines in the 'developing' world. Trends Pharmacol Sci, 31 (3), pp. 99-101. | Citations: 77 (Scopus) | Show Abstract | Read more

Since our ancestors began trading several millennia ago, counterfeit and substandard medicines have been a recurring problem, with history punctuated by crises in the supply of anti-microbials, such as fake cinchona bark in the 1600s and fake quinine in the 1800s. Unfortunately this problem persists, in particular afflicting unsuspecting patients in 'developing' countries. Poor-quality drugs are a vital (but neglected) public health problem. They contribute to a 'crevasse' between the enormous effort in therapeutic research and policy decisions and implementation of good-quality medicines.

Abuya TO, Fegan G, Amin AA, Akhwale WS, Noor AM, Snow RW, Marsh V. 2010. Evaluating different dimensions of programme effectiveness for private medicine retailer malaria control interventions in Kenya. PLoS One, 5 (1), pp. e8937. | Citations: 17 (Scopus) | Show Abstract | Read more

BACKGROUND: Private medicine retailers (PMRs) are key partners in the home management of fevers in many settings. Current evidence on effectiveness for PMR interventions at scale is limited. This study presents evaluation findings of two different programs implemented at moderate scale targeting PMRs for malaria control in the Kisii and Kwale districts of Kenya. Key components of this evaluation were measurement of program performance, including coverage, PMR knowledge, practices, and utilization based on spatial analysis. METHODOLOGY/PRINCIPAL FINDINGS: The study utilized mixed quantitative methods including retail audits and surrogate client surveys based on post-intervention cross-sectional surveys in intervention and control areas and mapping of intervention outlets. There was a large and significant impact on PMR knowledge and practices of the program in Kisii, with 60.5% of trained PMRs selling amodiaquine medicines in adequate doses compared to 2.8% of untrained ones (OR; 53.5: 95% CI 6.7, 428.3), a program coverage of 69.7% targeted outlets, and a potential utilization of about 30,000 children under five. The evaluation in Kwale also indicates a significant impact with 18.8% and 2.3% intervention and control PMRs selling amodiaquine with correct advice, respectively (OR; 9.4: 95% CI 1.1, 83.7), a program coverage of 25.3% targeted outlets, and a potential utilization of about 48,000 children under five. A provisional benchmark of 7.5 km was a reasonable threshold distance for households to access PMR services. CONCLUSIONS/SIGNIFICANCE: This evaluation show that PMR interventions operationalized in the district level settings are likely to impact PMR knowledge and practices and lead to increased coverage of appropriate treatment to target populations. There is value of evaluating different dimensions of public health programs, including quality, spatial access, and implementation practice. This approach strengthens the potential contribution of pragmatic study designs to evaluating public health programs in the real world.

Hanson J, Lee SJ, Mohanty S, Faiz MA, Anstey NM, Charunwatthana P, Yunus EB, Mishra SK, Tjitra E, Price RN et al. 2010. A simple score to predict the outcome of severe malaria in adults. Clin Infect Dis, 50 (5), pp. 679-685. | Citations: 47 (Scopus) | Show Abstract | Read more

BACKGROUND: World Health Organization treatment guidelines recommend that adults with severe malaria be admitted to an intensive care unit (ICU). However, ICU facilities are limited in the resource-poor settings where most malaria occurs. Identification of patients at greater risk of complications may facilitate their triage and resource allocation. METHODS: With use of data from a trial conducted in Southeast Asia (n=868), a logistic regression model was built to identify independent predictors of mortality among adults with severe malaria. A scoring system based on this model was tested in the original dataset and then validated in 2 series from Bangladesh (n=188) and Vietnam (n=292). RESULTS: Acidosis (base deficit) and cerebral malaria (measured as Glasgow Coma Score) were the main independent predictors of outcome. The 5-point Coma Acidosis Malaria (CAM) score was simply derived from these 2 variables. Mortality increased steadily with increasing score. A CAM score <2 predicted survival with a positive predictive value (PPV) of 95.8% (95% confidence interval [CI], 93%- 97.7%). Of the 14 of 331 patients who died with a CAM score <2, 11 (79%) had renal failure and death occurred late after hospital admission (median, 108 h; range, 40-360 h). Substitution of plasma bicarbonate as the measure of acidosis only slightly reduced the prognostic value of the model. Use of respiratory rate was inferior, but a score <2 still predicted survival with a PPV of 92.2% (95% CI, 89.1%-94.7%). CONCLUSIONS: Patients with a CAM score <2 at hospital admission may be safely treated in a general ward, provided that renal function can be monitored.

Harris SR, Feil EJ, Holden MTG, Quail MA, Nickerson EK, Chantratita N, Gardete S, Tavares A, Day N, Lindsay JA et al. 2010. Evolution of MRSA during hospital transmission and intercontinental spread. Science, 327 (5964), pp. 469-474. | Citations: 646 (Scopus) | Show Abstract | Read more

Current methods for differentiating isolates of predominant lineages of pathogenic bacteria often do not provide sufficient resolution to define precise relationships. Here, we describe a high-throughput genomics approach that provides a high-resolution view of the epidemiology and microevolution of a dominant strain of methicillin-resistant Staphylococcus aureus (MRSA). This approach reveals the global geographic structure within the lineage, its intercontinental transmission through four decades, and the potential to trace person-to-person transmission within a hospital environment. The ability to interrogate and resolve bacterial populations is applicable to a range of infectious diseases, as well as microbial ecology.

Okiro EA, White LJ, Ngama M, Cane PA, Medley GF, Nokes DJ. 2010. Duration of shedding of respiratory syncytial virus in a community study of Kenyan children. BMC Infect Dis, 10 (1), pp. 15. | Citations: 25 (Scopus) | Show Abstract | Read more

BACKGROUND: Our understanding of the transmission dynamics of respiratory syncytial virus (RSV) infection will be better informed with improved data on the patterns of shedding in cases not limited only to hospital admissions. METHODS: In a household study, children testing RSV positive by direct immunofluorescent antibody test (DFA) were enrolled. Nasal washings were scheduled right away, then every three days until day 14, every 7 days until day 28 and every 2 weeks until a maximum of 16 weeks, or until the first DFA negative RSV specimen. The relationship between host factors, illness severity and viral shedding was investigated using Cox regression methods. RESULTS: From 151 families a total of 193 children were enrolled with a median age of 21 months (range 1-164 months), 10% infants and 46% male. The rate of recovery from infection was 0.22/person/day (95% CI 0.19-0.25) equivalent to a mean duration of shedding of 4.5 days (95%CI 4.0-5.3), with a median duration of shedding of 4 days (IQR 2-6, range 1-14). Children with a history of RSV infection had a 40% increased rate of recovery i.e. shorter duration of viral shedding (hazard ratio 1.4, 95% CI 1.01-1.86). The rate of cessation of shedding did not differ significantly between males and females, by severity of infection or by age. CONCLUSION: We provide evidence of a relationship between the duration of shedding and history of infection, which may have a bearing on the relative role of primary versus re-infections in RSV transmission in the community.

Maude RJ, Hassan MU, Ghose A, Douthwaite ST, Faiz MA, Dondorp AM. 2010. Studies on severe malaria are still possible and essential. Clin Infect Dis, 50 (2), pp. 281-282. | Citations: 1 (Web of Science Lite) | Read more

Batra R, Cooper BS, Whiteley C, Patel AK, Wyncoll D, Edgeworth JD. 2010. Efficacy and limitation of a chlorhexidine-based decolonization strategy in preventing transmission of methicillin-resistant Staphylococcus aureus in an intensive care unit. Clin Infect Dis, 50 (2), pp. 210-217. | Citations: 135 (Scopus) | Show Abstract | Read more

BACKGROUND: Surface-active antiseptics, such as chlorhexidine, are increasingly being used as part of intervention programs to prevent methicillin-resistant Staphylococcus aureus (MRSA) transmission, despite limited evidence and potential for resistance. We report on the effect of an antiseptic protocol on acquisition of both endemic MRSA and an outbreak strain of MRSA sequence type 239 (designated TW). METHODS: Interrupted time-series data on MRSA acquisitions in two 15-bed intensive care units were analyzed using segmented regression models to estimate the effects of sequential introduction of an educational campaign, cohorting, and a chlorhexidine-based antiseptic protocol on transmission of TW and non-TW MRSA strains. Representative TW and non-TW MRSA strains were assessed for carriage of qacA/B genes and antiseptic susceptibility. RESULTS: The antiseptic protocol was associated with a highly significant, immediate 70% reduction in acquisition of non-TW MRSA strains (estimated model-averaged incidence rate ratio, 0.3; 95% confidence interval, 0.19-0.47) and an increase in acquisition of TW MRSA strains (estimated model-averaged incidence rate ratio, 3.85; 95% confidence interval, 0.80-18.59). There was only weak evidence of an effect of other interventions on MRSA transmission. All TW MRSA strains (21 of 21 isolates) and <5% (1 of 21 isolates) of non-TW MRSA strains tested carried the chlorhexidine resistance loci qacA/B. In vitro chlorhexidine minimum bactericidal concentrations of TW strains were 3-fold higher than those of non-TW MRSA strains, and in vivo, only patients with non-TW MRSA demonstrated a reduction in the number of colonization sites in response to chlorhexidine treatment. CONCLUSION: A chlorhexidine-based surface antiseptic protocol can interrupt transmission of MRSA in the intensive care unit, but strains carrying qacA/B genes may be unaffected or potentially spread more rapidly.

Makani J, Komba AN, Cox SE, Oruo J, Mwamtemi K, Kitundu J, Magesa P, Rwezaula S, Meda E, Mgaya J et al. 2010. Malaria in patients with sickle cell anemia: burden, risk factors, and outcome at the outpatient clinic and during hospitalization. Blood, 115 (2), pp. 215-220. | Citations: 65 (Scopus) | Show Abstract | Read more

Approximately 280,000 children are born with sickle cell anemia (SCA) in Africa annually, yet few survive beyond childhood. Falciparum malaria is considered a significant cause of this mortality. We conducted a 5-year prospective surveillance study for malaria parasitemia, clinical malaria, and severe malarial anemia (SMA) in Dar-es-Salaam, Tanzania, between 2004 and 2009. We recorded 10,491 visits to the outpatient clinic among 1808 patients with SCA and 773 visits among 679 patients without SCA. Similarly, we recorded 691 hospital admissions among 497 patients with SCA and 2017 in patients without SCA. Overall, the prevalence of parasitemia was lower in patients with SCA than in patients without SCA both at clinic (0.7% vs 1.6%; OR, 0.53; 95% CI, 0.32-0.86; P = .008) and during hospitalization (3.0% vs 5.6%; OR, 0.46; 95% CI, 0.25-0.94; P = .01). Furthermore, patients with SCA had higher rates of malaria during hospitalization than at clinic, the ORs being 4.29 (95% CI, 2.63-7.01; P < .001) for parasitemia, 17.66 (95% CI, 5.92-52.71; P < .001) for clinical malaria, and 21.11 (95% CI, 8.46-52.67; P < .001) for SMA. Although malaria was rare among patients with SCA, parasitemia during hospitalization was associated with both severe anemia and death. Effective treatment for malaria during severe illness episodes and further studies to determine the role chemoprophylaxis are required.

Thai KTD, Phuong HL, Thanh Nga TT, Giao PT, Hung LQ, Van Nam N, Binh TQ, Simmons C, Farrar J, Hien TT et al. 2010. Clinical, epidemiological and virological features of Dengue virus infections in Vietnamese patients presenting to primary care facilities with acute undifferentiated fever. J Infect, 60 (3), pp. 229-237. | Citations: 27 (Scopus) | Show Abstract | Read more

OBJECTIVES: To explore clinical and virological characteristics and describe the epidemiology of dengue in patients who presented with acute undifferentiated fever (AUF) at primary health centers (PHC) in Binh Thuan Province, Vietnam. METHODS: A prospective observational study was conducted from 2001 to 2006 to study the aetiology in AUF patients. Demographic and clinical information was obtained, and dengue polymerase chain reaction (RT-PCR) and serology were performed on a random selection of patients. RESULTS: Three hundred fifty-one serologically confirmed dengue patients including 68 primary and 283 secondary infections were included in this study. In 25% (86/351) dengue virus (DENV) was detected by RT-PCR among which 32 DENV-1, 16 DENV-2, 1 DENV-3 and 37 DENV-4 were identified. The predominant dengue serotype varied by year with seasonal fluctuation: DENV-4 in 2001-2002, DENV-1 and DENV-2 from 2003 to 2006. Primary dengue was more common in children. Higher viraemia levels (P=0.010) were found in primary infections compared to secondary infections. DENV-1 infected patients had higher viraemia levels than DENV-2 (P=0.003) and DENV-4 (P<0.001) infected patients. Clinical symptoms were often seen in adults. Few differences in clinical symptoms were found between primary and secondary infection and no significant differences in clinical symptoms between the serotypes were observed. CONCLUSIONS: Our data provide insight in the epidemiology, clinical profile and virological features of mild symptomatic dengue patients who presented to PHC with AUF in Vietnam.

Bode LGM, Kluytmans JAJW, Wertheim HFL, Bogaers D, Vandenbroucke-Grauls CMJE, Roosendaal R, Troelstra A, Box ATA, Voss A, van der Tweel I et al. 2010. Preventing surgical-site infections in nasal carriers of Staphylococcus aureus. N Engl J Med, 362 (1), pp. 9-17. | Citations: 602 (Scopus) | Show Abstract | Read more

BACKGROUND: Nasal carriers of Staphylococcus aureus are at increased risk for health care-associated infections with this organism. Decolonization of nasal and extranasal sites on hospital admission may reduce this risk. METHODS: In a randomized, double-blind, placebo-controlled, multicenter trial, we assessed whether rapid identification of S. aureus nasal carriers by means of a real-time polymerase-chain-reaction (PCR) assay, followed by treatment with mupirocin nasal ointment and chlorhexidine soap, reduces the risk of hospital-associated S. aureus infection. RESULTS: From October 2005 through June 2007, a total of 6771 patients were screened on admission. A total of 1270 nasal swabs from 1251 patients were positive for S. aureus. We enrolled 917 of these patients in the intention-to-treat analysis, of whom 808 (88.1%) underwent a surgical procedure. All the S. aureus strains identified on PCR assay were susceptible to methicillin and mupirocin. The rate of S. aureus infection was 3.4% (17 of 504 patients) in the mupirocin-chlorhexidine group, as compared with 7.7% (32 of 413 patients) in the placebo group (relative risk of infection, 0.42; 95% confidence interval [CI], 0.23 to 0.75). The effect of mupirocin-chlorhexidine treatment was most pronounced for deep surgical-site infections (relative risk, 0.21; 95% CI, 0.07 to 0.62). There was no significant difference in all-cause in-hospital mortality between the two groups. The time to the onset of nosocomial infection was shorter in the placebo group than in the mupirocin-chlorhexidine group (P=0.005). CONCLUSIONS: The number of surgical-site S. aureus infections acquired in the hospital can be reduced by rapid screening and decolonizing of nasal carriers of S. aureus on admission. (Current Controlled Trials number, ISRCTN56186788.)

Le QM, Wertheim HFL, Tran ND, van Doorn HR, Nguyen TH, Horby P, Vietnam H1N1 Investigation Team. 2010. A community cluster of oseltamivir-resistant cases of 2009 H1N1 influenza. N Engl J Med, 362 (1), pp. 86-87. | Citations: 77 (Scopus) | Read more

Basnyat B. 2010. Typhoid fever in the United States and antibiotic choice. JAMA, 303 (1), pp. 34. | Citations: 4 (Scopus) | Read more

Pullan RL, Bukirwa H, Staedke SG, Snow RW, Brooker S. 2010. Plasmodium infection and its risk factors in eastern Uganda. Malar J, 9 (1), pp. 2. | Citations: 55 (Scopus) | Show Abstract | Read more

BACKGROUND: Malaria is a leading cause of disease burden in Uganda, although surprisingly few contemporary, age-stratified data exist on malaria epidemiology in the country. This report presents results from a total population survey of malaria infection and intervention coverage in a rural area of eastern Uganda, with a specific focus on how risk factors differ between demographic groups in this population. METHODS: In 2008, a cross-sectional survey was conducted in four contiguous villages in Mulanda, sub-county in Tororo district, eastern Uganda, to investigate the epidemiology and risk factors of Plasmodium species infection. All permanent residents were invited to participate, with blood smears collected from 1,844 individuals aged between six months and 88 years (representing 78% of the population). Demographic, household and socio-economic characteristics were combined with environmental data using a Geographical Information System. Hierarchical models were used to explore patterns of malaria infection and identify individual, household and environmental risk factors. RESULTS: Overall, 709 individuals were infected with Plasmodium, with prevalence highest among 5-9 year olds (63.5%). Thin films from a random sample of 20% of parasite positive participants showed that 94.0% of infections were Plasmodium falciparum and 6.0% were P. malariae; no other species or mixed infections were seen. In total, 68% of households owned at least one mosquito although only 27% of school-aged children reported sleeping under a net the previous night. In multivariate analysis, infection risk was highest amongst children aged 5-9 years and remained high in older children. Risk of infection was lower for those that reported sleeping under a bed net the previous night and living more than 750 m from a rice-growing area. After accounting for clustering within compounds, there was no evidence for an association between infection prevalence and socio-economic status, and no evidence for spatial clustering. CONCLUSION: These findings demonstrate that mosquito net usage remains inadequate and is strongly associated with risk of malaria among school-aged children. Infection risk amongst adults is influenced by proximity to potential mosquito breeding grounds. Taken together, these findings emphasize the importance of increasing net coverage, especially among school-aged children.

Williams D, Gutiérrez JM, Harrison R, Warrell DA, White J, Winkel KD, Gopalakrishnakone P, Global Snake Bite Initiative Working Group, International Society on Toxinology. 2010. The Global Snake Bite Initiative: an antidote for snake bite. Lancet, 375 (9708), pp. 89-91. | Citations: 141 (Scopus) | Read more

Lee N, Wong CK, Chan PKS, Lindegardh N, White NJ, Hayden FG, Wong EHC, Wong KS, Cockram CS, Sung JJY, Hui DSC. 2010. Acute encephalopathy associated with influenza A infection in adults. Emerg Infect Dis, 16 (1), pp. 139-142. | Citations: 29 (Scopus) | Show Abstract | Read more

We report acute encephalopathy associated with influenza A infection in 3 adults. We detected high cerebrospinal fluid (CSF) and plasma concentrations of CXCL8/IL-8 and CCL2/MCP-1 (CSF/plasma ratios > or =3), and interleukin-6, CXCL10/IP-10, but no evidence of viral neuroinvasion. Patients recovered without sequelae. Hyperactivated cytokine response may play a role in pathogenesis.

Karema C, Imwong M, Fanello CI, Stepniewska K, Uwimana A, Nakeesathit S, Dondorp A, Day NP, White NJ. 2010. Molecular correlates of high-level antifolate resistance in Rwandan children with Plasmodium falciparum malaria. Antimicrob Agents Chemother, 54 (1), pp. 477-483. | Citations: 26 (Scopus) | Show Abstract | Read more

Antifolate drugs have an important role in the treatment of malaria. Polymorphisms in the genes encoding the dihydrofolate reductase and dihydropteroate synthetase enzymes cause resistance to the antifol and sulfa drugs, respectively. Rwanda has the highest levels of antimalarial drug resistance in Africa. We correlated the efficacy of chlorproguanil-dapsone plus artesunate (CPG-DDS+A) and amodiaquine plus sulfadoxine-pyrimethamine (AQ+SP) in children with uncomplicated malaria caused by Plasmodium falciparum parasites with pfdhfr and pfdhps mutations, which are known to confer reduced drug susceptibility, in two areas of Rwanda. In the eastern province, where the cure rates were low, over 75% of isolates had three or more pfdhfr mutations and two or three pfdhps mutations and 11% had the pfdhfr 164-Leu polymorphism. In the western province, where the cure rates were significantly higher (P < 0.001), the prevalence of multiple resistance mutations was lower and the pfdhfr I164L polymorphism was not found. The risk of treatment failure following the administration of AQ+SP more than doubled for each additional pfdhfr resistance mutation (odds ratio [OR] = 2.4; 95% confidence interval [CI] = 1.01 to 5.55; P = 0.048) and each pfdhps mutation (OR = 2.1; 95% CI = 1.21 to 3.54; P = 0.008). The risk of failure following CPG-DDS+A treatment was 2.2 times higher (95% CI = 1.34 to 3.7) for each additional pfdhfr mutation, whereas there was no association with mutations in the pfdhps gene (P = 0.13). The pfdhfr 164-Leu polymorphism is prevalent in eastern Rwanda. Antimalarial treatments with currently available antifol-sulfa combinations are no longer effective in Rwanda because of high-level resistance.

Rahman W, Chotivanich K, Silamut K, Tanomsing N, Hossain A, Faiz MA, Dondorp AM, Maude RJ. 2010. Plasmodium malariae in Bangladesh. Trans R Soc Trop Med Hyg, 104 (1), pp. 78-80. | Citations: 9 (Web of Science Lite) | Show Abstract | Read more

We describe a 32-year-old Bangladeshi male presenting with severe malaria caused by a mono-infection with Plasmodium malariae. Rosetting of infected and uninfected erythrocytes, a putative virulence factor in falciparum malaria, was observed in the blood slide. Severe disease caused by P. malariae is extremely rare. The patient made a rapid recovery with intravenous quinine treatment.

Flohr C, Tuyen LN, Quinnell RJ, Lewis S, Minh TT, Campbell J, Simmons C, Telford G, Brown A, Hien TT et al. 2010. Reduced helminth burden increases allergen skin sensitization but not clinical allergy: a randomized, double-blind, placebo-controlled trial in Vietnam. Clin Exp Allergy, 40 (1), pp. 131-142. | Citations: 73 (Scopus) | Show Abstract | Read more

BACKGROUND: Observational evidence suggests that infection with helminths protects against allergic disease and allergen skin sensitization. It is postulated that such effects are mediated by helminth-induced cytokine responses, in particular IL-10. OBJECTIVE: We tested this hypothesis in a rural area of central Vietnam where hookworm infection is endemic. METHODS: One thousand five hundred and sixty-six schoolchildren aged 6-17 were randomly allocated to receive either anti-helminthic therapy or a placebo at 0, 3, 6, and 9 months. We compared changes in the prevalence of exercise-induced bronchoconstriction, allergen skin sensitization, flexural eczema on skin examination, questionnaire-reported allergic disease (wheeze and rhinitis symptoms), and immunological parameters (hookworm-induced IFN-gamma, IL-5, IL-10) between 0 and 12 months. RESULTS: One thousand four hundred and eighty-seven children (95% of these randomized) completed the study. The most common helminth infections were hookworm (65%) and Ascaris lumbricoides (7%). There was no effect of the therapy on the primary outcome, exercise-induced bronchoconstriction (within-participant mean percent fall in peak flow from baseline after anti-helminthic treatment 2.25 (SD 7.3) vs. placebo 2.19 (SD 7.8, P=0.9), or on the prevalence of questionnaire-reported wheeze [adjusted odds ratio (OR)=1.16, 95% confidence interval (CI) 0.35-3.82, P=0.8] and rhinitis (adjusted OR=1.39, 0.89-2.15, P=0.1), or flexural dermatitis on skin examination (adjusted OR=1.15, 0.39-3.45, P=0.8). However, anti-helminthic therapy was associated with a significantly higher allergen skin sensitization risk (adjusted OR=1.31, 1.02-1.67, P=0.03). This effect was particularly strong for children infected with A. lumbricoides at baseline (adjusted OR=4.90, 1.48-16.19, P=0.009). Allergen skin sensitization was inversely related to hookworm-specific IL-10 at baseline (adjusted OR=0.76, 0.59-0.99, P=0.04). No cytokine tested, including IL-10, changed significantly after the anti-helminthic therapy compared with the placebo. CONCLUSION: A significant reduction in worm burden over a 12-month period in helminth-infected children increases the risk of allergen skin sensitization but not of clinical allergic disease. The effect on skin sensitization could not be fully explained by any of the immunological parameters tested.

Löwenberg EC, Charunwatthana P, Cohen S, van den Born B-J, Meijers JCM, Yunus EB, Hassan MU, Hoque G, Maude RJ, Nuchsongsin F et al. 2010. Severe malaria is associated with a deficiency of von Willebrand factor cleaving protease, ADAMTS13. Thromb Haemost, 103 (1), pp. 181-187. | Citations: 42 (Scopus) | Show Abstract | Read more

Severe falciparum malaria remains a major killer in tropical countries. Central in the pathophysiology is mechanical obstruction in the microcirculation caused by cytoadherence and sequestration of parasitized erythrocytes. However, the pathogenesis of many features complicating severe malaria, including coma, renal failure and thrombocytopenia, remains incompletely understood. These disease manifestations are also key features of thrombotic thrombocytopenic purpura, a life-threatening disease strongly associated with a deficiency of the von Willebrand factor (VWF) cleaving protease, ADAMTS13. We measured plasma ADAMTS13 activity, VWF antigen and VWF propeptide levels in 30 patients with severe falciparum malaria, 12 patients with uncomplicated falciparum malaria and 14 healthy Bangladeshi controls. In patients with severe malaria ADAMTS13 activity levels were markedly decreased in comparison to normal controls (mean [95%CI]: 23% [20-26] vs. 64% [55-72]) and VWF antigen and propeptide concentrations were significantly elevated (VWF antigen: 439% [396-481] vs. 64% [46-83]; VWF propeptide: 576% [481-671] vs. 69% [59-78]). In uncomplicated malaria VWF levels were also increased compared to healthy controls but ADAMTS13 activity was normal. The results suggest that decreased ADAMTS13 activity in combination with increased VWF concentrations may contribute to the complications in severe malaria.

Tan PT, Heiny AT, Miotto O, Salmon J, Marques ETA, Lemonnier F, August JT. 2010. Conservation and diversity of influenza A H1N1 HLA-restricted T cell epitope candidates for epitope-based vaccines. PLoS One, 5 (1), pp. e8754. | Citations: 32 (Scopus) | Show Abstract | Read more

BACKGROUND: The immune-related evolution of influenza viruses is exceedingly complex and current vaccines against influenza must be reformulated for each influenza season because of the high degree of antigenic drift among circulating influenza strains. Delay in vaccine production is a serious problem in responding to a pandemic situation, such as that of the current H1N1 strain. Immune escape is generally attributed to reduced antibody recognition of the viral hemagglutinin and neuraminidase proteins whose rate of mutation is much greater than that of the internal non-structural proteins. As a possible alternative, vaccines directed at T cell epitope domains of internal influenza proteins, that are less susceptible to antigenic variation, have been investigated. METHODOLOGY/PRINCIPAL FINDINGS: HLA transgenic mouse strains expressing HLA class I A*0201, A*2402, and B*0702, and class II DRB1*1501, DRB1*0301 and DRB1*0401 were immunized with 196 influenza H1N1 peptides that contained residues of highly conserved proteome sequences of the human H1N1, H3N2, H1N2, H5N1, and avian influenza A strains. Fifty-four (54) peptides that elicited 63 HLA-restricted peptide-specific T cell epitope responses were identified by IFN-gamma ELISpot assay. The 54 peptides were compared to the 2007-2009 human H1N1 sequences for selection of sequences in the design of a new candidate H1N1 vaccine, specifically targeted to highly-conserved HLA-restricted T cell epitopes. CONCLUSIONS/SIGNIFICANCE: Seventeen (17) T cell epitopes in PB1, PB2, and M1 were selected as vaccine targets based on sequence conservation over the past 30 years, high functional avidity, non-identity to human peptides, clustered localization, and promiscuity to multiple HLA alleles. These candidate vaccine antigen sequences may be applicable to any avian or human influenza A virus.

Gaudin K, Millet P, Fawaz F, Olliaro P, White NJ, Cassus-Coussère C, Agbahoungha U, Dubost J-P. 2010. Investigation of porous graphitic carbon at high-temperature liquid chromatography with evaporative light scattering detection for the analysis of the drug combination artesunate--azithromycin for the treatment of severe malaria. J Chromatogr A, 1217 (1), pp. 75-81. | Citations: 9 (Web of Science Lite) | Show Abstract | Read more

Artesunate combined therapies represent the best option for the treatment of malaria and require the development of new methods of analysis. Retention, selectivity and detection with high-temperature liquid chromatography-porous graphitic carbon-evaporative light scattering detection was studied for artesunate and azithromycin separation. Organic solvent, concentration of organic modifiers, temperature and flow rate were all relevant parameters to optimize this separation. The behaviour of artesunate in the tested conditions appeared close to a neutral compound. In CH(3)OH, only azithromycin retention was dramatically altered depending on the [triethylamine]/[formic acid] ratio and on the temperature, whereas in CH(3)CN, azithromycin, artesunate, artemisinin and dihydroartemisinin retentions decreased with the temperature increase whatever the organic modifier ratio. The best efficiency was obtained with CH(3)CN. 25% variation of the concentration values of the organic modifiers did not significantly influenced the retention. The sensitivity of ELSD increased with the flow rate decrease. Peak area and S/N ratio dramatically decreased with the flow rate increase by 10- and 5-fold for artesunate and azithromycin, respectively. Non-linear calibration curves were obtained for both artesunate and azithromycin.

Chapman SJ, Vannberg FO, Khor CC, Rautanen A, Maskell NA, Davies CWH, Moore CE, Day NP, Crook DW, Davies RJO, Hill AVS. 2010. Mannose-binding lectin genotypes: lack of association with susceptibility to thoracic empyema. BMC Med Genet, 11 (1), pp. 5. | Citations: 5 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: The role of the innate immune protein mannose-binding lectin (MBL) in host defence against severe respiratory infection remains controversial. Thoracic empyema is a suppurative lung infection that arises as a major complication of pneumonia and is associated with a significant mortality. Although the pathogenesis of thoracic empyema is poorly understood, genetic susceptibility loci for this condition have recently been identified. The possible role of MBL genotypic deficiency in susceptibility to thoracic empyema has not previously been reported. METHODS: To investigate this further we compared the frequencies of the six functional MBL polymorphisms in 170 European individuals with thoracic empyema and 225 healthy control individuals. RESULTS: No overall association was observed between MBL genotypic deficiency and susceptibility to thoracic empyema (2 x 2 Chi square = 0.02, P = 0.87). Furthermore, no association was seen between MBL deficiency and susceptibility to the Gram-positive or pneumococcal empyema subgroups. MBL genotypic deficiency did not associate with progression to death or requirement for surgery. CONCLUSIONS: Our results suggest that MBL genotypic deficiency does not associate with susceptibility to thoracic empyema in humans.

Miotto O, Heiny AT, Albrecht R, García-Sastre A, Tan TW, August JT, Brusic V. 2010. Complete-proteome mapping of human influenza A adaptive mutations: implications for human transmissibility of zoonotic strains. PLoS One, 5 (2), pp. e9025. | Citations: 47 (Scopus) | Show Abstract | Read more

BACKGROUND: There is widespread concern that H5N1 avian influenza A viruses will emerge as a pandemic threat, if they become capable of human-to-human (H2H) transmission. Avian strains lack this capability, which suggests that it requires important adaptive mutations. We performed a large-scale comparative analysis of proteins from avian and human strains, to produce a catalogue of mutations associated with H2H transmissibility, and to detect their presence in avian isolates. METHODOLOGY/PRINCIPAL FINDINGS: We constructed a dataset of influenza A protein sequences from 92,343 public database records. Human and avian sequence subsets were compared, using a method based on mutual information, to identify characteristic sites where human isolates present conserved mutations. The resulting catalogue comprises 68 characteristic sites in eight internal proteins. Subtype variability prevented the identification of adaptive mutations in the hemagglutinin and neuraminidase proteins. The high number of sites in the ribonucleoprotein complex suggests interdependence between mutations in multiple proteins. Characteristic sites are often clustered within known functional regions, suggesting their functional roles in cellular processes. By isolating and concatenating characteristic site residues, we defined adaptation signatures, which summarize the adaptive potential of specific isolates. Most adaptive mutations emerged within three decades after the 1918 pandemic, and have remained remarkably stable thereafter. Two lineages with stable internal protein constellations have circulated among humans without reassorting. On the contrary, H5N1 avian and swine viruses reassort frequently, causing both gains and losses of adaptive mutations. CONCLUSIONS: Human host adaptation appears to be complex and systemic, involving nearly all influenza proteins. Adaptation signatures suggest that the ability of H5N1 strains to infect humans is related to the presence of an unusually high number of adaptive mutations. However, these mutations appear unstable, suggesting low pandemic potential of H5N1 in its current form. In addition, adaptation signatures indicate that pandemic H1N1/09 strain possesses multiple human-transmissibility mutations, though not an unusually high number with respect to swine strains that infected humans in the past. Adaptation signatures provide a novel tool for identifying zoonotic strains with the potential to infect humans.

Dellicour S, Tatem AJ, Guerra CA, Snow RW, ter Kuile FO. 2010. Quantifying the number of pregnancies at risk of malaria in 2007: a demographic study. PLoS Med, 7 (1), pp. e1000221. | Citations: 223 (Scopus) | Show Abstract | Read more

BACKGROUND: Comprehensive and contemporary estimates of the number of pregnancies at risk of malaria are not currently available, particularly for endemic areas outside of Africa. We derived global estimates of the number of women who became pregnant in 2007 in areas with Plasmodium falciparum and P. vivax transmission. METHODS AND FINDINGS: A recently published map of the global limits of P. falciparum transmission and an updated map of the limits of P. vivax transmission were combined with gridded population data and growth rates to estimate total populations at risk of malaria in 2007. Country-specific demographic data from the United Nations on age, sex, and total fertility rates were used to estimate the number of women of child-bearing age and the annual rate of live births. Subregional estimates of the number of induced abortions and country-specific stillbirths rates were obtained from recently published reviews. The number of miscarriages was estimated from the number of live births and corrected for induced abortion rates. The number of clinically recognised pregnancies at risk was then calculated as the sum of the number of live births, induced abortions, spontaneous miscarriages, and stillbirths among the population at risk in 2007. In 2007, 125.2 million pregnancies occurred in areas with P. falciparum and/or P. vivax transmission resulting in 82.6 million live births. This included 77.4, 30.3, 13.1, and 4.3 million pregnancies in the countries falling under the World Health Organization (WHO) regional offices for South-East-Asia (SEARO) and the Western-Pacific (WPRO) combined, Africa (AFRO), Europe and the Eastern Mediterranean (EURO/EMRO), and the Americas (AMRO), respectively. Of 85.3 million pregnancies in areas with P. falciparum transmission, 54.7 million occurred in areas with stable transmission and 30.6 million in areas with unstable transmission (clinical incidence <1 per 10,000 population/year); 92.9 million occurred in areas with P. vivax transmission, 53.0 million of which occurred in areas in which P. falciparum and P. vivax co-exist and 39.9 million in temperate regions with P. vivax transmission only. CONCLUSIONS: In 2007, 54.7 million pregnancies occurred in areas with stable P. falciparum malaria and a further 70.5 million in areas with exceptionally low malaria transmission or with P. vivax only. These represent the first contemporary estimates of the global distribution of the number of pregnancies at risk of P. falciparum and P. vivax malaria and provide a first step towards a more informed estimate of the geographical distribution of infection rates and the corresponding disease burden of malaria in pregnancy.

Price EP, Hornstra HM, Limmathurotsakul D, Max TL, Sarovich DS, Vogler AJ, Dale JL, Ginther JL, Leadem B, Colman RE et al. 2010. Within-host evolution of Burkholderia pseudomallei in four cases of acute melioidosis. PLoS Pathog, 6 (1), pp. e1000725. | Citations: 38 (Scopus) | Show Abstract | Read more

Little is currently known about bacterial pathogen evolution and adaptation within the host during acute infection. Previous studies of Burkholderia pseudomallei, the etiologic agent of melioidosis, have shown that this opportunistic pathogen mutates rapidly both in vitro and in vivo at tandemly repeated loci, making this organism a relevant model for studying short-term evolution. In the current study, B. pseudomallei isolates cultured from multiple body sites from four Thai patients with disseminated melioidosis were subjected to fine-scale genotyping using multilocus variable-number tandem repeat analysis (MLVA). In order to understand and model the in vivo variable-number tandem repeat (VNTR) mutational process, we characterized the patterns and rates of mutations in vitro through parallel serial passage experiments of B. pseudomallei. Despite the short period of infection, substantial divergence from the putative founder genotype was observed in all four melioidosis cases. This study presents a paradigm for examining bacterial evolution over the short timescale of an acute infection. Further studies are required to determine whether the mutational process leads to phenotypic alterations that impact upon bacterial fitness in vivo. Our findings have important implications for future sampling strategies, since colonies in a single clinical sample may be genetically heterogeneous, and organisms in a culture taken late in the infective process may have undergone considerable genetic change compared with the founder inoculum.

Rowa Y, Abuya TO, Mutemi WK, Ochola S, Molyneux S, Marsh V. 2010. Factors influencing implementation of the Ministry of Health-led private medicine retailer programmes on malaria in Kenya. BMC Public Health, 10 (1), pp. 93. | Citations: 6 (Scopus) | Show Abstract | Read more

BACKGROUND: Kenya has experienced a number of retail sector initiatives aimed at improving access to antimalarial medicines. This study explored stakeholders' perceptions of the role of private medicine retailers (PMRs), the value and feasibility of programme goals, perceived programme impact, factors influencing implementation and recommendations in three districts of Kenya. METHODS: This study was part of a larger evaluation of PMR programmes, including quantitative and qualitative components. The qualitative research was conducted to assess implementation processes and actors' experiences in the programmes, through focus group discussions with trained PMRs and mothers of children under five years, and in-depth interviews with programme managers, trainers and co-trainers. RESULTS: PMRs were perceived to provide rapid cheap treatment for non-serious conditions and used as a deliberate and continuously evaluated choice between different treatment sources. All stakeholders supported programme goals and most PMRs described increased customer satisfaction, more rational purchasing of medicine stock and increased medicine sales after participation. Factors undermining programme implementation included a lack of MoH resources to train and monitor large numbers of PMRs, the relative instability of outlets, medicines stocked and retail personnel, the large number of proprietary brands and financial challenges to retailers in stocking antimalarial medicines, and their customers in buying them. Unambiguous national support and a broad range of strategies are important to strengthen the feasibility of change in OTC antimalarial use. CONCLUSIONS: Understanding the context and implementation processes of PMR programmes and the perspectives of key actors are critical to identifying measures to support their effective implementation. Financial barriers underlie many described challenges, with important implications for policies on subsidies in this sector. In spite of barriers to implementation, increased exposure to programme activities promoted trust and improved relationships between PMRs and their clients and trainers, strengthening feasibility of such interventions. Public information can strengthen PMR training programmes by engaging local communities and may facilitate performance monitoring of PMRs by their clients.

Wertheim HFL, Puthavathana P, Nghiem NM, van Doorn HR, Nguyen TV, Pham HV, Subekti D, Harun S, Malik S, Robinson J et al. 2010. Laboratory capacity building in Asia for infectious disease research: experiences from the South East Asia Infectious Disease Clinical Research Network (SEAICRN). PLoS Med, 7 (4), pp. e1000231. | Citations: 14 (Scopus) | Show Abstract | Read more

Enhancing laboratory capacity is essential for generating reliable and accurate data from clinical research, especially in resource-constrained settings. Local well-trained laboratory experts and scientists are important to research, and must participate actively in scientific activities and continuing education programs. Improving laboratory capacity is more than supplying new equipment and reagents; it also includes a long-term commitment to staff training, quality control, and biosafety. Improved laboratory capacity optimizes responses to an epidemic or an outbreak of a novel virulent pathogens, and can support international agendas to reduce the impact of pandemic influenza viruses. © 2010 Wertheim et al.

Hien TT, Boni MF, Bryant JE, Ngan TT, Wolbers M, Nguyen TD, Truong NT, Dung NT, Ha DQ, Hien VM et al. 2010. Early pandemic influenza (2009 H1N1) in Ho Chi Minh City, Vietnam: a clinical virological and epidemiological analysis. PLoS Med, 7 (5), pp. e1000277. | Citations: 36 (Scopus) | Show Abstract | Read more

BACKGROUND: To date, little is known about the initial spread and response to the 2009 pandemic of novel influenza A ("2009 H1N1") in tropical countries. Here, we analyse the early progression of the epidemic from 26 May 2009 until the establishment of community transmission in the second half of July 2009 in Ho Chi Minh City (HCMC), Vietnam. In addition, we present detailed systematic viral clearance data on 292 isolated and treated patients and the first three cases of selection of resistant virus during treatment in Vietnam. METHODS AND FINDINGS: Data sources included all available health reports from the Ministry of Health and relevant health authorities as well as clinical and laboratory data from the first confirmed cases isolated at the Hospital for Tropical Diseases in HCMC. Extensive reverse transcription (RT)-PCR diagnostics on serial samples, viral culture, neuraminidase-inhibition testing, and sequencing were performed on a subset of 2009 H1N1 confirmed cases. Virological (PCR status, shedding) and epidemiological (incidence, isolation, discharge) data were combined to reconstruct the initial outbreak and the establishment of community transmission. From 27 April to 24 July 2009, approximately 760,000 passengers who entered HCMC on international flights were screened at the airport by a body temperature scan and symptom questionnaire. Approximately 0.15% of incoming passengers were intercepted, 200 of whom tested positive for 2009 H1N1 by RT-PCR. An additional 121 out of 169 nontravelers tested positive after self-reporting or contact tracing. These 321 patients spent 79% of their PCR-positive days in isolation; 60% of PCR-positive days were spent treated and in isolation. Influenza-like illness was noted in 61% of patients and no patients experienced pneumonia or severe outcomes. Viral clearance times were similar among patient groups with differing time intervals from illness onset to treatment, with estimated median clearance times between 2.6 and 2.8 d post-treatment for illness-to-treatment intervals of 1-4 d, and 2.0 d (95% confidence interval 1.5-2.5) when treatment was started on the first day of illness. CONCLUSIONS: The patients described here represent a cross-section of infected individuals that were identified by temperature screening and symptom questionnaires at the airport, as well as mildly symptomatic to moderately ill patients who self-reported to hospitals. Data are observational and, although they are suggestive, it is not possible to be certain whether the containment efforts delayed community transmission in Vietnam. Viral clearance data assessed by RT-PCR showed a rapid therapeutic response to oseltamivir.

Nga TVT, Karkey A, Dongol S, Thuy HN, Dunstan S, Holt K, Tu LTP, Campbell JI, Chau TT, Chau NVV et al. 2010. The sensitivity of real-time PCR amplification targeting invasive Salmonella serovars in biological specimens. BMC Infect Dis, 10 (1), pp. 125. | Citations: 44 (Scopus) | Show Abstract | Read more

BACKGROUND: PCR amplification for the detection of pathogens in biological material is generally considered a rapid and informative diagnostic technique. Invasive Salmonella serovars, which cause enteric fever, can be commonly cultured from the blood of infected patients. Yet, the isolation of invasive Salmonella serovars from blood is protracted and potentially insensitive. METHODS: We developed and optimised a novel multiplex three colour real-time PCR assay to detect specific target sequences in the genomes of Salmonella serovars Typhi and Paratyphi A. We performed the assay on DNA extracted from blood and bone marrow samples from culture positive and negative enteric fever patients. RESULTS: The assay was validated and demonstrated a high level of specificity and reproducibility under experimental conditions. All bone marrow samples tested positive for Salmonella, however, the sensitivity on blood samples was limited. The assay demonstrated an overall specificity of 100% (75/75) and sensitivity of 53.9% (69/128) on all biological samples. We then tested the PCR detection limit by performing bacterial counts after inoculation into blood culture bottles. CONCLUSIONS: Our findings corroborate previous clinical findings, whereby the bacterial load of S. Typhi in peripheral blood is low, often below detection by culture and, consequently, below detection by PCR. Whilst the assay may be utilised for environmental sampling or on differing biological samples, our data suggest that PCR performed directly on blood samples may be an unsuitable methodology and a potentially unachievable target for the routine diagnosis of enteric fever.

Aslam A, Chan H, Warrell DA, Misbah S, Ogg GS. 2010. Tracking antigen-specific T-cells during clinical tolerance induction in humans. PLoS One, 5 (6), pp. e11028. | Citations: 34 (Scopus) | Show Abstract | Read more

Allergen immunotherapy presents an opportunity to define mechanisms of induction of clinical tolerance in humans. Significant progress has been made in our understanding of changes in T cell responses during immunotherapy, but existing work has largely been based on functional T cell assays. HLA-peptide-tetrameric complexes allow the tracking of antigen-specific T-cell populations based on the presence of specific T-cell receptors and when combined with functional assays allow a closer assessment of the potential roles of T-cell anergy and clonotype evolution. We sought to develop tools to facilitate tracking of antigen-specific T-cell populations during wasp-venom immunotherapy in people with wasp-venom allergy. We first defined dominant immunogenic regions within Ves v 5, a constituent of wasp venom that is known to represent a target antigen for T-cells. We next identified HLA-DRB1*1501 restricted epitopes and used HLA class II tetrameric complexes alongside cytokine responses to Ves v 5 to track T-cell responses during immunotherapy. In contrast to previous reports, we show that there was a significant initial induction of IL-4 producing antigen-specific T-cells within the first 3-5 weeks of immunotherapy which was followed by reduction of circulating effector antigen-specific T-cells despite escalation of wasp-venom dosage. However, there was sustained induction of IL-10-producing and FOXP3 positive antigen-specific T cells. We observed that these IL-10 producing cells could share a common precursor with IL-4-producing T cells specific for the same epitope. Clinical tolerance induction in humans is associated with dynamic changes in frequencies of antigen-specific T-cells, with a marked loss of IL-4-producing T-cells and the acquisition of IL-10-producing and FOXP3-positive antigen-specific CD4+ T-cells that can derive from a common shared precursor to pre-treatment effector T-cells. The development of new approaches to track antigen specific T-cell responses during immunotherapy can provide novel insights into mechanisms of tolerance induction in humans and identify new potential treatment targets.

Tricou V, Vu HTT, Quynh NVN, Nguyen CVV, Tran HT, Farrar J, Wills B, Simmons CP. 2010. Comparison of two dengue NS1 rapid tests for sensitivity, specificity and relationship to viraemia and antibody responses. BMC Infect Dis, 10 (1), pp. 142. | Citations: 81 (Scopus) | Show Abstract | Read more

BACKGROUND: Dengue is a major public health problem in tropical and subtropical countries. Rapid and easy diagnosis of dengue can assist patient triage and care-management. The detection of DENV NS1 on rapid lateral flow tests offers a fast route to a presumptive dengue diagnosis but careful evaluations are urgently needed as more and more people use them. METHODS: The sensitivity and specificity of the Bio-Rad NS1 Ag Strip and SD Dengue Duo (NS1/IgM/IgG) lateral flow rapid tests were evaluated in a panel of plasma samples from 245 Vietnamese patients with RT-PCR confirmed dengue and 47 with other febrile illnesses. RESULTS: The NS1 rapid tests had similar diagnostic sensitivities (respectively 61.6% and 62.4%) in confirmed dengue cases but were 100% specific. When IgM/IgG results from the SD Dengue Duo were included in the test interpretation, the sensitivity improved significantly from 62.4% with NS1 alone to 75.5% when NS1 and/or IgM was positive and 83.7% when NS1 and/or IgM and/or IgG was positive. Both NS1 assays were significantly more sensitive for primary than secondary dengue. NS1 positivity was associated with the underlying viraemia as NS1-positive samples had a significantly higher viraemia than NS1-negative samples. CONCLUSIONS: These data suggest that the NS1 test component of these assays are highly specific and have similar levels of sensitivity. The IgM parameter in the SD Duo test improved overall test sensitivity without compromising specificity. The SD Dengue Duo lateral flow rapid test deserves further prospective evaluation in dengue endemic settings.

Fox A, Horby P, Ha NH, Hoa LNM, Lam NT, Simmons C, Farrar J, Van Kinh N, Wertheim H. 2010. Influenza A H5N1 and HIV co-infection: case report. BMC Infect Dis, 10 (1), pp. 167. | Citations: 1 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: The role of adaptive immunity in severe influenza is poorly understood. The occurrence of influenza A/H5N1 in a patient with HIV provided a rare opportunity to investigate this. CASE PRESENTATION: A 30-year-old male was admitted on day 4 of influenza-like-illness with tachycardia, tachypnea, hypoxemia and bilateral pulmonary infiltrates. Influenza A/H5N1 and HIV tests were positive and the patient was treated with Oseltamivir and broad-spectrum antibiotics. Initially his condition improved coinciding with virus clearance by day 6. He clinically deteriorated as of day 10 with fever recrudescence and increasing neutrophil counts and died on day 16. His admission CD4 count was 100/microl and decreased until virus was cleared. CD8 T cells shifted to a CD27+CD28- phenotype. Plasma chemokine and cytokine levels were similar to those found previously in fatal H5N1. CONCLUSIONS: The course of H5N1 infection was not notably different from other cases. Virus was cleared despite profound CD4 T cell depletion and aberrant CD8 T cell activation but this may have increased susceptibility to a fatal secondary infection.

Mirghani SE, Nour BYM, Bushra SM, Elhassan IM, Snow RW, Noor AM. 2010. The spatial-temporal clustering of Plasmodium falciparum infection over eleven years in Gezira State, The Sudan. Malar J, 9 (1), pp. 172. | Citations: 14 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Malaria infection and disease exhibit microgeographic heterogeneity which if predictable could have implications for designing small-area intervention. Here, the space-time clustering of Plasmodium falciparum infections using data from repeat cross-sectional surveys in Gezira State, a low transmission area in northern Sudan, is investigated. METHODS: Data from cross-sectional surveys undertaken in January each year from 1999-2009 in 88 villages in the Gezira state were assembled. During each survey, about a 100 children between the ages two to ten years were sampled to examine the presence of P. falciparum parasites. In 2009, all the villages were mapped using global positioning systems. Cluster level data were analysed for spatial-only and space-time clustering using the Bernoulli model and the significance of clusters were tested using the Kulldorff scan statistic. RESULTS: Over the study period, 96,022 malaria slide examinations were undertaken and the P. falciparum prevalence was 8.6% in 1999 and by 2009 this had reduced to 1.6%. The cluster analysis showed the presence of one significant spatial-only cluster in each survey year and one significant space-time cluster over the whole study period. The primary spatial-only clusters in 10/11 years were either contained within or overlapped with the primary space-time cluster. CONCLUSION: The results of the study confirm the generally low malaria transmission in the state of Gezira and the presence of spatial and space-time clusters concentrated around a specific area in the south of the state. Improved surveillance data that allows for the analysis of seasonality, age and other risk factors need to be collected to design effective small area interventions as Gezira state targets malaria elimination.

Abuya T, Amin A, Molyneux S, Akhwale W, Marsh V, Gilson L. 2010. Importance of strategic management in the implementation of private medicine retailer programmes: case studies from three districts in Kenya. BMC Health Serv Res, 10 Suppl 1 (Suppl 1), pp. S7. | Citations: 5 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: The home-management of malaria strategy seeks to improve prompt and effective anti-malarial drug use through the informal sector, with a potential channel being the Private Medicine Retailers (PMRs). Previous evaluations of PMR programmes focused on their impact on retailer knowledge and practices, with limited evidence about the influence of implementation processes on the impacts at scale. This paper examines how the implementation processes of three PMR programmes in Kenya, each scaled up within a district, contributed to the outcomes observed. These were a Ministry of Health programme in Kwale district; and two programmes supported by non-governmental organizations in collaboration with government in Kisii Central and Bungoma districts. METHODS: The research methods included 24 focus group discussions with clients and PMRs, 19 in-depth interviews with implementing actors, document review and a diary of events. The data were analysed using the combination of a broad policy analysis framework and more specific scaling up/diffusion of innovations frameworks. RESULTS: The Kisii programme, a case study of successful implementation, was underpinned by good relationships between district health managers and a "resource team", supported by a memorandum of understanding which enabled successful implementation. It had flexible budgetary and decision making processes which were responsive to local contexts, and took account of local socio-economic activities. In contrast, the Kwale programme, which had implementation challenges, was characterised by a complex funding process, with lengthy timelines, that was tied to the government financial management system which constrained implementation Although there was a flexible funding system in Bungoma, a perceived lack of transparency in fund management, inadequate management of inter-organisational relationships, and inability to adapt and respond to changing circumstances led to implementation difficulties. CONCLUSIONS: For effective scaling up of PMR programmes, the provision of technical support and adequate resources are vital, but not sufficient on their own. An active strategy to manage relationships between implementing actors through effective communication mechanisms is essential. Successful outcomes may be realised if a strong and transparent management system, including management of financial resources, is put in place. This study provides evidence of the value of assessing implementation processes as part of impact evaluation for public health programmes.

Lang TA, White NJ, Tran HT, Farrar JJ, Day NPJ, Fitzpatrick R, Angus BJ, Denis E, Merson L, Cheah PY et al. 2010. Clinical research in resource-limited settings: enhancing research capacity and working together to make trials less complicated. PLoS Negl Trop Dis, 4 (6), pp. e619. | Citations: 38 (Scopus) | Read more

Gething PW, Kirui VC, Alegana VA, Okiro EA, Noor AM, Snow RW. 2010. Estimating the number of paediatric fevers associated with malaria infection presenting to Africa's public health sector in 2007. PLoS Med, 7 (7), pp. e1000301. | Citations: 50 (Scopus) | Show Abstract | Read more

BACKGROUND: As international efforts to increase the coverage of artemisinin-based combination therapy in public health sectors gather pace, concerns have been raised regarding their continued indiscriminate presumptive use for treating all childhood fevers. The availability of rapid-diagnostic tests to support practical and reliable parasitological diagnosis provides an opportunity to improve the rational treatment of febrile children across Africa. However, the cost effectiveness of diagnosis-based treatment polices will depend on the presumed numbers of fevers harbouring infection. Here we compute the number of fevers likely to present to public health facilities in Africa and the estimated number of these fevers likely to be infected with Plasmodium falciparum malaria parasites. METHODS AND FINDINGS: We assembled first administrative-unit level data on paediatric fever prevalence, treatment-seeking rates, and child populations. These data were combined in a geographical information system model that also incorporated an adjustment procedure for urban versus rural areas to produce spatially distributed estimates of fever burden amongst African children and the subset likely to present to public sector clinics. A second data assembly was used to estimate plausible ranges for the proportion of paediatric fevers seen at clinics positive for P. falciparum in different endemicity settings. We estimated that, of the 656 million fevers in African 0-4 y olds in 2007, 182 million (28%) were likely to have sought treatment in a public sector clinic of which 78 million (43%) were likely to have been infected with P. falciparum (range 60-103 million). CONCLUSIONS: Spatial estimates of childhood fevers and care-seeking rates can be combined with a relational risk model of infection prevalence in the community to estimate the degree of parasitemia in those fevers reaching public health facilities. This quantification provides an important baseline comparison of malarial and nonmalarial fevers in different endemicity settings that can contribute to ongoing scientific and policy debates about optimum clinical and financial strategies for the introduction of new diagnostics. These models are made publicly available with the publication of this paper.

Vu TTH, Holmes EC, Duong V, Nguyen TQ, Tran TH, Quail M, Churcher C, Parkhill J, Cardosa J, Farrar J et al. 2010. Emergence of the Asian 1 genotype of dengue virus serotype 2 in viet nam: in vivo fitness advantage and lineage replacement in South-East Asia. PLoS Negl Trop Dis, 4 (7), pp. e757. | Citations: 64 (Web of Science Lite) | Show Abstract | Read more

A better description of the extent and structure of genetic diversity in dengue virus (DENV) in endemic settings is central to its eventual control. To this end we determined the complete coding region sequence of 187 DENV-2 genomes and 68 E genes from viruses sampled from Vietnamese patients between 1995 and 2009. Strikingly, an episode of genotype replacement was observed, with Asian 1 lineage viruses entirely displacing the previously dominant Asian/American lineage viruses. This genotype replacement event also seems to have occurred within DENV-2 in Thailand and Cambodia, suggestive of a major difference in viral fitness. To determine the cause of this major evolutionary event we compared both the infectivity of the Asian 1 and Asian/American genotypes in mosquitoes and their viraemia levels in humans. Although there was little difference in infectivity in mosquitoes, we observed significantly higher plasma viraemia levels in paediatric patients infected with Asian 1 lineage viruses relative to Asian/American viruses, a phenotype that is predicted to result in a higher probability of human-to-mosquito transmission. These results provide a mechanistic basis to a marked change in the genetic structure of DENV-2 and more broadly underscore that an understanding of DENV evolutionary dynamics can inform the development of vaccines and anti-viral drugs.

Abubakar IS, Abubakar SB, Habib AG, Nasidi A, Durfa N, Yusuf PO, Larnyang S, Garnvwa J, Sokomba E, Salako L et al. 2010. Randomised controlled double-blind non-inferiority trial of two antivenoms for saw-scaled or carpet viper (Echis ocellatus) envenoming in Nigeria. PLoS Negl Trop Dis, 4 (7), pp. e767. | Citations: 53 (Scopus) | Show Abstract | Read more

BACKGROUND: In West Africa, envenoming by saw-scaled or carpet vipers (Echis ocellatus) causes great morbidity and mortality, but there is a crisis in supply of effective and affordable antivenom (ISRCTN01257358). METHODS: In a randomised, double-blind, controlled, non-inferiority trial, "EchiTAb Plus-ICP" (ET-Plus) equine antivenom made by Instituto Clodomiro Picado was compared to "EchiTAb G" (ET-G) ovine antivenom made by MicroPharm, which is the standard of care in Nigeria and was developed from the original EchiTAb-Fab introduced in 1998. Both are caprylic acid purified whole IgG antivenoms. ET-G is monospecific for Echis ocellatus antivenom (initial dose 1 vial) and ET-Plus is polyspecific for E. ocellatus, Naja nigricollis and Bitis arietans (initial dose 3 vials). Both had been screened by pre-clinical and preliminary clinical dose-finding and safety studies. Patients who presented with incoagulable blood, indicative of systemic envenoming by E. ocellatus, were recruited in Kaltungo, north-eastern Nigeria. Those eligible and consenting were randomly allocated with equal probability to receive ET-Plus or ET-G. The primary outcome was permanent restoration of blood coagulability 6 hours after the start of treatment, assessed by a simple whole blood clotting test repeated 6, 12, 18, 24 and 48 hr after treatment. Secondary (safety) outcomes were the incidences of anaphylactic, pyrogenic and late serum sickness-type antivenom reactions. FINDINGS: Initial doses permanently restored blood coagulability at 6 hours in 161/194 (83.0%) of ET-Plus and 156/206 (75.7%) of ET-G treated patients (Relative Risk [RR] 1.10 one-sided 95% CI lower limit 1.01; P = 0.05). ET-Plus caused early reactions on more occasions than did ET-G [50/194 (25.8%) and 39/206 (18.9%) respectively RR (1.36 one-sided 95% CI 1.86 upper limit; P = 0.06). These reactions were classified as severe in 21 (10.8%) and 11 (5.3%) of patients, respectively. CONCLUSION: At these doses, ET-Plus was slightly more effective but ET-G was slightly safer. Both are recommended for treating E. ocellatus envenoming in Nigeria. TRIAL REGISTRATION: Current Controlled Trials ISRCTN01257358.

Tricou V, Minh NN, Van TP, Lee SJ, Farrar J, Wills B, Tran HT, Simmons CP. 2010. A randomized controlled trial of chloroquine for the treatment of dengue in Vietnamese adults. PLoS Negl Trop Dis, 4 (8), pp. e785. | Citations: 88 (Scopus) | Show Abstract | Read more

BACKGROUND: There is currently no licensed antiviral drug for treatment of dengue. Chloroquine (CQ) inhibits the replication of dengue virus (DENV) in vitro. METHODS AND FINDINGS: A double-blind, randomized, placebo-controlled trial of CQ in 307 adults hospitalized for suspected DENV infection was conducted at the Hospital for Tropical Diseases (Ho Chi Minh City, Vietnam) between May 2007 and July 2008. Patients with illness histories of 72 hours or less were randomized to a 3-day course of CQ (n = 153) or placebo (n = 154). Laboratory-confirmation of DENV infection was made in 257 (84%) patients. The primary endpoints were time to resolution of DENV viraemia and time to resolution of DENV NS1 antigenaemia. In patients treated with CQ there was a trend toward a longer duration of DENV viraemia (hazard ratio (HR) = 0.80, 95% CI 0.62-1.05), but we did not find any difference for the time to resolution of NS1 antigenaemia (HR = 1.07, 95% CI 0.76-1.51). Interestingly, CQ was associated with a significant reduction in fever clearance time in the intention-to-treat population (HR = 1.37, 95% CI 1.08-1.74) but not in the per-protocol population. There was also a trend towards a lower incidence of dengue hemorrhagic fever (odds ratio = 0.60, PP 95% CI 0.34-1.04) in patients treated with CQ. Differences in levels of T cell activation or pro- or anti-inflammatory plasma cytokine concentrations between CQ- and placebo-treated patients did not explain the trend towards less dengue hemorrhagic fever in the CQ arm. CQ was associated with significantly more adverse events, primarily vomiting. CONCLUSIONS: CQ does not reduce the durations of viraemia and NS1 antigenaemia in dengue patients. Further trials, with appropriate endpoints, would be required to determine if CQ treatment has any clinical benefit in dengue. TRIAL REGISTRATION: Current Controlled Trials number ISRCTN38002730.

Taylor WRJ, Burhan E, Wertheim H, Soepandi PZ, Horby P, Fox A, Benamore R, de Simone L, Hien TT, Chappuis F. 2010. Avian influenza--a review for doctors in travel medicine. Travel Med Infect Dis, 8 (1), pp. 1-12. | Citations: 5 (Scopus) | Show Abstract | Read more

First identified in humans in Hong Kong, influenza A/H5N1, known commonly as avian influenza, has caused human disease in 15 countries around the world. Although the current number of confirmed patients is tiny compared to seasonal and the recently emerged H1N1 'swine' influenza, H5N1 remains a candidate for the next highly pathogenic influenza pandemic. Currently, H5N1 has very limited ability to spread from person-to-person but this may change because of mutation or reassortment with other influenza viruses leading to an influenza pandemic with high mortality. If this occurs travellers are likely to be affected and travel medicine doctors will need to consider avian influenza in returning febrile travellers. The early clinical features may be dismissed easily as 'the flu' resulting in delayed treatment. Treatment options are limited. Oral oseltamivir alone has been the most commonly used drug but mortality remains substantial, up to 80% in Indonesia. Intravenous peramivir has been filed for registration and IV zanamivir is being developed. This review will focus on the epidemiological and clinical features of influenza A/H5N1 avian influenza and will highlight aspects relevant to travel medicine doctors.

Rose AMC, Mueller JE, Gerstl S, Njanpop-Lafourcade B-M, Page A-L, Nicolas P, Traoré RO, Caugant DA, Guerin PJ. 2010. Meningitis dipstick rapid test: evaluating diagnostic performance during an urban Neisseria meningitidis serogroup A outbreak, Burkina Faso, 2007. PLoS One, 5 (6), pp. e11086. | Citations: 16 (Scopus) | Show Abstract | Read more

Meningococcal meningitis outbreaks occur every year during the dry season in the "meningitis belt" of sub-Saharan Africa. Identification of the causative strain is crucial before launching mass vaccination campaigns, to assure use of the correct vaccine. Rapid agglutination (latex) tests are most commonly available in district-level laboratories at the beginning of the epidemic season; limitations include a short shelf-life and the need for refrigeration and good technical skills. Recently, a new dipstick rapid diagnostic test (RDT) was developed to identify and differentiate disease caused by meningococcal serogroups A, W135, C and Y. We evaluated the diagnostic performance of this dipstick RDT during an urban outbreak of meningitis caused by N. meningitidis serogroup A in Ouagadougou, Burkina Faso; first against an in-country reference standard of culture and/or multiplex PCR; and second against culture and/or a highly sensitive nested PCR technique performed in Oslo, Norway. We included 267 patients with suspected acute bacterial meningitis. Using the in-country reference standard, 50 samples (19%) were positive. Dipstick RDT sensitivity (N = 265) was 70% (95%CI 55-82) and specificity 97% (95%CI 93-99). Using culture and/or nested PCR, 126/259 (49%) samples were positive; dipstick RDT sensitivity (N = 257) was 32% (95%CI 24-41), and specificity was 99% (95%CI 95-100). We found dipstick RDT sensitivity lower than values reported from (i) assessments under ideal laboratory conditions (>90%), and (ii) a prior field evaluation in Niger [89% (95%CI 80-95)]. Specificity, however, was similar to (i), and higher than (ii) [62% (95%CI 48-75)]. At this stage in development, therefore, other tests (e.g., latex) might be preferred for use in peripheral health centres. We highlight the value of field evaluations for new diagnostic tests, and note relatively low sensitivity of a reference standard using multiplex vs. nested PCR. Although the former is the current standard for bacterial meningitis surveillance in the meningitis belt, nested PCR performed in a certified laboratory should be used as an absolute reference when evaluating new diagnostic tests.

Baker S, Favorov M, Dougan G. 2010. Searching for the elusive typhoid diagnostic. BMC Infect Dis, 10 (1), pp. 45. | Citations: 60 (Scopus) | Show Abstract | Read more

Typhoid (enteric) fever is still a common disease in many developing countries but current diagnostic tests are inadequate. Studies on pathogenesis and genomics have provided new insight into the organisms that cause enteric fever. Better understanding of the microorganisms explains, in part, why our current typhoid methodologies are limited in their diagnostic information and why developing new strategies may be a considerable challenge. Here we discuss the current position of typhoid diagnostics, highlight the need for technological improvements and suggest potential ways of advancing this area.

Cheah PY, Lwin KM, Phaiphun L, Maelankiri L, Parker M, Day NP, White NJ, Nosten F. 2010. Community engagement on the Thai-Burmese border: rationale, experience and lessons learnt. Int Health, 2 (2), pp. 123-129. | Citations: 17 (Scopus) | Show Abstract | Read more

Community engagement is increasingly promoted in developing countries, especially in international health research, but there is little published experience. The Shoklo Malaria Research Unit (SMRU) conducts research with refugees, migrant workers, displaced people, and day migrants on the Thai-Burmese border, and has recently facilitated the set up of the Tak Province Border Community Ethics Advisory Board (T-CAB). Valuable lessons have been learnt from consultation with the T-CAB especially in the area of participant recruitment and the informed consent process. A lot of new research questions have emerged from consultation with the T-CAB. This paper describes our experience, lessons learnt and the unique challenges faced working with the T-CAB from its initial conception to date. We conclude that consultation with the T-CAB has made improvements in our research in particular operational and ethical aspects of our studies.

Cheah PY, Lwin KM, Phaiphun L, Maelankiri L, Parker M, Day NP, White NJ, Nosten F. 2010. Community engagement on the Thai-Burmese border: rationale, experience and lessons learnt International Health,

Ashley EA, Stepniewska K, Lindegardh N, Annerberg A, Tarning J, McGready R, Phaiphun L, Singhasivanon P, White NJ, Nosten F. 2010. Comparison of plasma, venous and capillary blood levels of piperaquine in patients with uncomplicated falciparum malaria. Eur J Clin Pharmacol, 66 (7), pp. 705-712. | Citations: 18 (Web of Science Lite) | Show Abstract | Read more

PURPOSE: Dihydroartemisinin-piperaquine (DP) is a fixed-dose artemisinin-based combination treatment. Field pharmacokinetic studies would be simplified and facilitated by being able to use small volume capillary assays rather than venous blood. The aim of this study was to describe the relationship between piperaquine concentrations measured in capillary blood, venous blood and venous plasma. METHODS: Samples of plasma, whole blood obtained by venesection and capillary blood were taken simultaneously from patients with uncomplicated Plasmodium falciparum malaria treated with DP between 0 and 9 weeks after treatment. Piperaquine concentrations in venous and capillary samples were measured using solid phase extraction and analysis by liquid chromatography with ultraviolet detection. RESULTS: A total of 161 sets of the three measures were obtained from 54 patients. Piperaquine concentrations in the venous blood samples were approximately twofold higher and those in the capillary blood samples were threefold higher than the corresponding venous plasma concentrations. Capillary blood piperaquine concentrations were approximately 1.7-fold higher than venous blood concentrations, and this difference also increased with time. CONCLUSION: Differences in whole blood and plasma levels of piperaquine suggest compartmentalisation of the drug within blood cells, as also occurs with the structurally related quinoline chloroquine. The relationship between piperaquine concentrations in the venous plasma, venous blood and capillary blood is variable and unpredictable at low concentrations. However, within the range of concentrations usually present in patients between 3 and 21 days after treatment with currently recommended doses, the relationship between capillary and venous whole blood is predictable; consequently, capillary blood sampling can be used in field assessments.

Trung DT, Wills B. 2010. Systemic vascular leakage associated with dengue infections - the clinical perspective. Curr Top Microbiol Immunol, 338 (1), pp. 57-66. | Citations: 34 (Web of Science Lite) | Show Abstract | Read more

Vascular leakage is the most serious complication of dengue infection. However, despite considerable progress in understanding the immunological derangements associated with dengue, the pathogenic mechanisms underlying the change in vascular permeability remain unclear. Lack of suitable model systems that manifest permeability characteristics similar to human vascular endothelium has seriously impeded research in this area. Similarly, limited knowledge of the factors regulating intrinsic microvascular permeability in health, together with limited understanding of the alterations seen in disease states in general, has also hampered progress. Fortunately considerable advances have been made in the field of endothelial biology in recent years, especially following appreciation of the crucial role played by the endothelial surface glycocalyx, acting in concert with underlying cellular structures, in regulating fluid flow across the microvasculature. We review what is known about vascular leakage during dengue infections, particularly in relation to current knowledge of vascular physiology, and discuss potential areas of research that may help to elucidate the complex nature of this singular phenomenon in the future.

Linard C, Alegana VA, Noor AM, Snow RW, Tatem AJ. 2010. A high resolution spatial population database of Somalia for disease risk mapping. Int J Health Geogr, 9 (1), pp. 45. | Citations: 31 (Scopus) | Show Abstract | Read more

BACKGROUND: Millions of Somali have been deprived of basic health services due to the unstable political situation of their country. Attempts are being made to reconstruct the health sector, in particular to estimate the extent of infectious disease burden. However, any approach that requires the use of modelled disease rates requires reasonable information on population distribution. In a low-income country such as Somalia, population data are lacking, are of poor quality, or become outdated rapidly. Modelling methods are therefore needed for the production of contemporary and spatially detailed population data. RESULTS: Here land cover information derived from satellite imagery and existing settlement point datasets were used for the spatial reallocation of populations within census units. We used simple and semi-automated methods that can be implemented with free image processing software to produce an easily updatable gridded population dataset at 100 × 100 meters spatial resolution. The 2010 population dataset was matched to administrative population totals projected by the UN. Comparison tests between the new dataset and existing population datasets revealed important differences in population size distributions, and in population at risk of malaria estimates. These differences are particularly important in more densely populated areas and strongly depend on the settlement data used in the modelling approach. CONCLUSIONS: The results show that it is possible to produce detailed, contemporary and easily updatable settlement and population distribution datasets of Somalia using existing data. The 2010 population dataset produced is freely available as a product of the AfriPop Project and can be downloaded from: http://www.afripop.org.

Le VT, Phan TQ, Do QH, Nguyen BH, Lam QB, Bach VC, Truong HK, Tran TH, Nguyen VVC, Tran TT et al. 2010. Viral etiology of encephalitis in children in southern Vietnam: results of a one-year prospective descriptive study. PLoS Negl Trop Dis, 4 (10), pp. e854. | Citations: 38 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Acute encephalitis is an important and severe disease in children in Vietnam. However, little is known about the etiology while such knowledge is essential for optimal prevention and treatment. To identify viral causes of encephalitis, in 2004 we conducted a one-year descriptive study at Children's Hospital Number One, a referral hospital for children in southern Vietnam including Ho Chi Minh City. METHODOLOGY/PRINCIPAL FINDINGS: Children less than 16 years of age presenting with acute encephalitis of presumed viral etiology were enrolled. Diagnostic efforts included viral culture, serology and real time (RT)-PCRs. A confirmed or probable viral causative agent was established in 41% of 194 enrolled patients. The most commonly diagnosed causative agent was Japanese encephalitis virus (n = 50, 26%), followed by enteroviruses (n = 18, 9.3%), dengue virus (n = 9, 4.6%), herpes simplex virus (n = 1), cytomegalovirus (n = 1) and influenza A virus (n = 1). Fifty-seven (29%) children died acutely. Fatal outcome was independently associated with patient age and Glasgow Coma Scale (GCS) on admission. CONCLUSIONS/SIGNIFICANCE: Acute encephalitis in children in southern Vietnam is associated with high mortality. Although the etiology remains unknown in a majority of the patients, the result from the present study may be useful for future design of treatment and prevention strategies of the disease. The recognition of GCS and age as predictive factors may be helpful for clinicians in managing the patient.

Thanh TT, Pawestri HA, Ngoc NM, Hien VM, Syahrial H, Trung NV, van Doorn RH, Wertheim HFL, Chau NVV, Ha do Q et al. 2010. A real-time RT-PCR for detection of clade 1 and 2 H5N1 influenza A virus using locked nucleic acid (LNA) TaqMan probes. Virol J, 7 (1), pp. 46. | Citations: 7 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: The emergence and co-circulation of two different clades (clade 1 and 2) of H5N1 influenza viruses in Vietnam necessitates the availability of a diagnostic assay that can detect both variants. RESULTS: We developed a single real-time RT-PCR assay for detection of both clades of H5N1 viruses, directly from clinical specimens, using locked nucleic acid TaqMan probes. Primers and probe used in this assay were designed based on a highly conserved region in the HA gene of H5N1 viruses. The analytical sensitivity of the assay was < 0.5 PFU and 10-100 ssDNA plasmid copies. A total of 106 clinical samples (58 from patients infected with clade 1, 2.1 or 2.3 H5N1 viruses and 48 from uninfected or seasonal influenza A virus-infected individuals) were tested by the assay. The assay showed 97% concordance with initial diagnostics for H5 influenza virus infection with a specificity of 100%. CONCLUSIONS: This assay is a useful tool for diagnosis of H5N1 virus infections in regions where different genetic clades are co-circulating.

Tran Tan T, Pawestri HA, My NN, Minh HV, Syahrial H, Vu TN, Van Doorn RH, Wertheim HF, Van Vinh CN, Quang HD et al. 2010. A real-time RT-PCR for detection of clade 1 and 2 H5N1 Influenza A virus using Locked Nucleic Acid (LNA) TaqMan probes Virology Journal, 7 | Citations: 6 (Scopus) | Show Abstract | Read more

Background. The emergence and co-circulation of two different clades (clade 1 and 2) of H5N1 influenza viruses in Vietnam necessitates the availability of a diagnostic assay that can detect both variants. Results. We developed a single real-time RT-PCR assay for detection of both clades of H5N1 viruses, directly from clinical specimens, using locked nucleic acid TaqMan probes. Primers and probe used in this assay were designed based on a highly conserved region in the HA gene of H5N1 viruses. The analytical sensitivity of the assay was < 0.5 PFU and 10 - 100 ssDNA plasmid copies. A total of 106 clinical samples (58 from patients infected with clade 1, 2.1 or 2.3 H5N1 viruses and 48 from uninfected or seasonal influenza A virus-infected individuals) were tested by the assay. The assay showed 97% concordance with initial diagnostics for H5 influenza virus infection with a specificity of 100%. Conclusions. This assay is a useful tool for diagnosis of H5N1 virus infections in regions where different genetic clades are co-circulating. © 2010 Tan et al; licensee BioMed Central Ltd.

van de Beek D, Farrar JJ, de Gans J, Mai NTH, Molyneux EM, Peltola H, Peto TE, Roine I, Scarborough M, Schultsz C et al. 2010. Adjunctive dexamethasone in bacterial meningitis: a meta-analysis of individual patient data. Lancet Neurol, 9 (3), pp. 254-263. | Citations: 132 (Scopus) | Show Abstract | Read more

BACKGROUND: Dexamethasone improves outcome for some patients with bacterial meningitis, but not others. We aimed to identify which patients are most likely to benefit from dexamethasone treatment. METHODS: We did a meta-analysis of individual patient data from the randomised, double-blind, placebo-controlled trials of dexamethasone for bacterial meningitis in patients of all ages for which raw data were available. The pre-determined outcome measures were death at the time of first follow-up, death or severe neurological sequelae at 1 month follow-up, death or any neurological sequelae at first follow-up, and death or severe bilateral hearing loss at first follow-up. Combined odds ratios (ORs) and tests for heterogeneity were calculated using conventional Mantel-Haenszel statistics. We also did exploratory analysis of hearing loss among survivors and other exploratory subgroup analyses by use of logistic regression. FINDINGS: Data from 2029 patients from five trials were included in the analysis (833 [41.0%] aged <15 years). HIV infection was confirmed or likely in 580 (28.6%) patients and bacterial meningitis was confirmed in 1639 (80.8%). Dexamethasone was not associated with a significant reduction in death (270 of 1019 [26.5%] on dexamethasone vs 275 of 1010 [27.2%] on placebo; OR 0.97, 95% CI 0.79-1.19), death or severe neurological sequelae or bilateral severe deafness (42.3%vs 44.3%; 0.92, 0.76-1.11), death or any neurological sequelae or any hearing loss (54.2%vs 57.4%; 0.89, 0.74-1.07), or death or severe bilateral hearing loss (36.4%vs 38.9%; 0.89, 0.73-1.69). However, dexamethasone seemed to reduce hearing loss among survivors (24.1%vs 29.5%; 0.77, 0.60-0.99, p=0.04). Dexamethasone had no effect in any of the prespecified subgroups, including specific causative organisms, pre-dexamethasone antibiotic treatment, HIV status, or age. Pooling of the mortality data with those of all other published trials did not significantly change the results. INTERPRETATION: Adjunctive dexamethasone in the treatment of acute bacterial meningitis does not seem to significantly reduce death or neurological disability. There were no significant treatment effects in any of the prespecified subgroups. The benefit of adjunctive dexamethasone for all or any subgroup of patients with bacterial meningitis thus remains unproven. FUNDING: Wellcome Trust UK.

Horby P, Sudoyo H, Viprakasit V, Fox A, Thai PQ, Yu H, Davila S, Hibberd M, Dunstan SJ, Monteerarat Y et al. 2010. What is the evidence of a role for host genetics in susceptibility to influenza A/H5N1? Epidemiology and Infection, 138 (11), pp. 1550-1558. | Citations: 37 (Scopus) | Show Abstract | Read more

The apparent family clustering of avian influenza A/H5N1 has led several groups to postulate the existence of a host genetic influence on susceptibility to A/H5N1, yet the role of host factors on the risk of A/H5N1 disease has received remarkably little attention compared to the efforts focused on viral factors. We examined the epidemiological patterns of human A/H5N1 cases, their possible explanations, and the plausibility of a host genetic effect on susceptibility to A/H5N1 infection. The preponderance of familial clustering of cases and the relative lack of non-familial clusters, the occurrence of related cases separated by time and place, and the paucity of cases in some highly exposed groups such as poultry cullers, are consistent with a host genetic effect. Animal models support the biological plausibility of genetic susceptibility to A/H5N1. Although the evidence is circumstantial, host genetic factors are a parsimonious explanation for the unusual epidemiology of human A/H5N1 cases and warrant further investigation. Copyright © 2010 Cambridge University Press.

Yu H, Liao Q, Yuan Y, Zhou L, Xiang N, Huai Y, Guo X, Zheng Y, Van Doorn HR, Farrar J et al. 2010. Effectiveness of oseltamivir on disease progression and viral RNA shedding in patients with mild pandemic 2009 influenza A H1N1: Opportunistic retrospective study of medical charts in China BMJ (Online), 341 (7775), pp. 714. | Citations: 77 (Scopus) | Show Abstract | Read more

Objective: To describe the clinical features and effectiveness of oseltamivir on disease progression and viral RNA shedding in patients with mild pandemic 2009 influenza A(H1N1) virus infection. Design: Opportunistic retrospective review of medical charts of patients with confirmed 2009 H1N1 identified through the national surveillance system in China from May to July 2009. Setting: Under coordination of the Ministry of Health, local health departments were asked to collect medical records of confirmed patients and send them to the Chinese Centre for Disease Control and Prevention on a voluntary basis as part of the public health response. Population: 1291 patients with confirmed 2009 H1N1 infection and available data for chart review. Main outcome measures: Demographic characteristics, comorbidities, symptoms and signs, laboratory tests, findings on chest radiography, antiviral treatment, duration of fever, and duration of viral RNA shedding. Results: The median age of 1291 patients was 20 years (interquartile range 12-26); 701 (54%) were male. The most common symptoms were fever (820, 64%), cough (864, 67%), sore throat (425, 33%), sputum (239, 19%), and rhinorrhoea (228, 18%). Of 920 patients who underwent chest radiography, 110 (12%) had abnormal findings consistent with pneumonia. Some 983 (76%) patients were treated with oseltamivir from a median of the third day of symptoms (2-4). No patients required admission to the intensive care unit or mechanical ventilation. 2009 H1N1 was shed from one day before onset of symptoms to up to eight days after onset in most (91%) patients, with a median of 5 (3-6) days of shedding after onset. Treatment with oseltamivir significantly protected against subsequent development of radiographically confirmed pneumonia (odds ratio 0.12, 95% confidence interval 0.08 to 0.18), and treatment started within two days of symptom onset reduced the duration of fever and viral RNA shedding. Conclusions: Chinese patients with 2009 H1N1 infection predominantly presented with features of uncomplicated, self limiting acute respiratory illness. 2009 H1N1 might be shed longer than seasonal influenza virus. Treatment with oseltamivir was associated with a significantly reduced development of radiographically confirmed pneumonia and a shorter duration of fever and viral RNA shedding. Though these patients benefited from treatment, the findings should be interpreted with caution as the study was retrospective and not all patients underwent chest radiography.

Buchy P, Vong S, Chu S, Garcia J-M, Hien TT, Hien VM, Channa M, Ha DQ, Chau NVV, Simmons C et al. 2010. Kinetics of neutralizing antibodies in patients naturally infected by H5N1 virus. PLoS One, 5 (5), pp. e10864. | Citations: 44 (Scopus) | Show Abstract | Read more

BACKGROUND: Little is known about the kinetics of anti-H5 neutralizing antibodies in naturally H5N1-infected patients with severe clinical illness or asymptomatic infection. METHODS: Using H5N1 microneutralisation (MN) and H5-pseudotype particle-based microneutralisation assays (H5pp) we analyzed sera sequentially obtained from 11 severely ill patients diagnosed by RT-PCR (follow-up range 1-139 weeks of disease onset) and 31 asymptomatically infected individuals detected in a sero-epidemiological study after exposure to H5N1 virus (follow-up range: 1-2 month-11 months after exposure). RESULTS: Of 44 sera from 11 patients with H5N1 disease, 70% tested positive by MN (antibody titre > or = 80) after 2 weeks and 100% were positive by 3 weeks after disease onset. The geometric mean MN titers in severely ill patients were 540 at 1-2 months and 173 at 10-12 months and thus were higher than the titers from asymptomatic individuals (149 at 1-2 months, 62.2 at 10-12 months). Fractional polynomial regression analysis demonstrated that in all severely ill patients, positive titers persisted beyond 2 years of disease onset, while 10 of 23 sera collected 10-11 months after exposure in asymptomatically infected individuals tested negative. CONCLUSIONS: Our results indicate that people with asymptomatic H5N1 infection have lower H5N1 antibody titres compared to those with severe illness and that in many asymptomatically infected patients the antibody titer decreased to levels below the threshold of positivity within one year. These data are essential for the design and interpretation of sero-epidemiological studies.

Horby P, Wertheim H, Ha NH, Trung NV, Trinh DT, Taylor W, Ha NM, Lien TTM, Farrar J, Van Kinh N. 2010. Stimulating the development of national Streptococcus suis guidelines in Viet Nam through a strategic research partnership. Bull World Health Organ, 88 (6), pp. 458-461. | Citations: 3 (Web of Science Lite) | Show Abstract | Read more

PROBLEM: Streptococcus suis is a common cause of adult bacterial meningitis in Viet Nam, and possibly other parts of Asia, yet this disabling infection has been largely neglected. Prevention, diagnosis and treatment are relatively straightforward and affordable but, in early 2007, no national diagnostic, case management or prevention guidelines existed in Viet Nam. APPROACH: Enhanced detection of S. suis infections was established in 2007 as part of a collaborative research programme between the National Hospital for Tropical Diseases, a key national hospital with very close links to the Ministry of Health, and a research group affiliated with Oxford University based in Viet Nam. The results were reported directly to policy-makers at the Ministry of Health. LOCAL SETTING: Viet Nam is a low-income country with a health-care system that has seen considerable improvements and increased autonomy. However, parts of the system remain fairly centralized the Ministry of Health. RELEVANT CHANGES: Following the improved detection and reporting of S. suis cases, the Ministry of Health issued guidance to all hospitals in Viet Nam on the clinical and laboratory diagnosis, treatment and prevention of S. suis. A public health laboratory diagnostic service was established at the National Institute of Hygiene and Epidemiology and training courses were conducted for clinicians and microbiologists. Ministry of Health guidance on surveillance and control of communicable diseases was updated to include a section on S. suis. LESSONS LEARNT: Research collaborations can efficiently inform and influence national responses if they are well positioned to reach policy-makers.

Chau TNB, Anders KL, Lien LB, Hung NT, Hieu LTM, Tuan NM, Thuy TT, Phuong LT, Tham NTH, Lanh MN et al. 2010. Clinical and virological features of Dengue in Vietnamese infants. PLoS Negl Trop Dis, 4 (4), pp. e657. | Citations: 35 (Scopus) | Show Abstract | Read more

BACKGROUND: Infants account for a small proportion of the overall dengue case burden in endemic countries but can be clinically more difficult to manage. The clinical and laboratory features in infants with dengue have not been extensively characterised. METHODOLOGY/PRINCIPAL FINDINGS: This prospective, cross-sectional descriptive study of infants hospitalized with dengue was conducted in Vietnam from November 2004 to December 2007. More than two-thirds of 303 infants enrolled on clinical suspicion of dengue had a serologically confirmed dengue virus (DENV) infection. Almost all were primary dengue infections and 80% of the infants developed DHF/DSS. At the time of presentation and during hospitalization, the clinical signs and symptoms in infants with dengue were difficult to distinguish from those with other febrile illnesses, suggesting that in infants early laboratory confirmation could assist appropriate management. Detection of plasma NS1 antigen was found to be a sensitive marker of acute dengue in infants with primary infection, especially in the first few days of illness. CONCLUSIONS/SIGNIFICANCE: Collectively, these results provide a systematic description of the clinical features of dengue in infants and highlight the value of NS1 detection for diagnosis.

McGready R, Nosten F. 2010. New Malaria Drugs (volume 71, number 1, 2010) Drug Development Research, 71 (3), pp. 219-220. | Read more

Boel ME, Lee SJ, Rijken MJ, Paw MK, Pimanpanarak M, Tan SO, Singhasivanon P, Nosten F, McGready R. 2010. Castor Oil for Induction of Labor: Not Harmful, Not Helpful Obstetrical & Gynecological Survey, 65 (2), pp. 77-78. | Citations: 2 (Scopus) | Read more

Piola P, Nabasumba C, Turyakira E, Dhorda M, Lindegardh N, Nyehangane D, Snounou G, Ashley EA, McGready R, Nosten F, Guerin PJ. 2010. Efficacy and safety of artemether-lumefantrine compared with quinine in pregnant women with uncomplicated Plasmodium falciparum malaria: an open-label, randomised, non-inferiority trial. Lancet Infect Dis, 10 (11), pp. 762-769. | Citations: 61 (Scopus) | Show Abstract | Read more

BACKGROUND: Malaria in pregnancy is associated with maternal and fetal morbidity and mortality. In 2006, WHO recommended use of artemisinin-based combination treatments during the second or third trimesters, but data on efficacy and safety in Africa were scarce. We aimed to assess whether artemether-lumefantrine was at least as efficacious as oral quinine for the treatment of uncomplicated falciparum malaria during the second and third trimesters of pregnancy in Mbarara, Uganda. METHODS: We did an open-label, randomised, non-inferiority trial between October, 2006, and May, 2009, at the antenatal clinics of the Mbarara University of Science and Technology Hospital in Uganda. Pregnant women were randomly assigned (1:1) by computer generated sequence to receive either quinine hydrochloride or artemether-lumefantrine, and were followed up weekly until delivery. Our primary endpoint was cure rate at day 42, confirmed by PCR. The non-inferiority margin was a difference in cure rate of 5%. Analysis of efficacy was for all randomised patients without study deviations that could have affected the efficacy outcome. This study was registered with ClinicalTrials.gov, number NCT00495508. FINDINGS: 304 women were randomly assigned, 152 to each treatment group. By day 42, 16 patients were lost to follow-up and 25 were excluded from the analysis. At day 42, 137 (99.3%) of 138 patients taking artemether-lumefantrine and 122 (97.6%) of 125 taking quinine were cured-difference 1.7% (lower limit of 95% CI -0.9). There were 290 adverse events in the quinine group and 141 in the artemether-lumefantrine group. INTERPRETATION: Artemisinin derivatives are not inferior to oral quinine for the treatment of uncomplicated malaria in pregnancy and might be preferable on the basis of safety and efficacy. FUNDING: Médecins Sans Frontières and the European Commission.

Maude RJ, Lubell Y, Socheat D, Yeung S, Saralamba S, Pongtavornpinyo W, Cooper BS, Dondorp AM, White NJ, White LJ. 2010. The role of mathematical modelling in guiding the science and economics of malaria elimination. Int Health, 2 (4), pp. 239-246. | Citations: 8 (Web of Science Lite) | Show Abstract | Read more

Unprecedented efforts are now underway to eliminate malaria from many regions. Despite the enormous financial resources committed, if malaria elimination is perceived as failing it is likely that this funding will not be sustained. It is imperative that methods are developed to use the limited data available to design site-specific, cost-effective elimination programmes. Mathematical modelling is a way of including mechanistic understanding to use available data to make predictions. Different strategies can be evaluated much more rapidly than is possible through trial and error in the field. Mathematical modelling has great potential as a tool to guide and inform current elimination efforts. Economic modelling weighs costs against characterised effects or predicted benefits in order to determine the most cost-efficient strategy but has traditionally used static models of disease not suitable for elimination. Dynamic mathematical modelling and economic modelling techniques need to be combined to contribute most effectively to ongoing policy discussions. We review the role of modelling in previous malaria control efforts as well as the unique nature of elimination and the consequent need for its explicit modelling, and emphasise the importance of good disease surveillance. The difficulties and complexities of economic evaluation of malaria control, particularly the end stages of elimination, are discussed.

Koh GCKW, Maude RJ, Paris DH, Newton PN, Blacksell SD. 2010. Review: Diagnosis of scrub typhus American Journal of Tropical Medicine and Hygiene, 82 (3), pp. 368-370. | Citations: 95 (Scopus) | Show Abstract | Read more

Scrub typhus is transmitted by trombiculid mites and is endemic to East and Southeast Asia and Northern Australia. The clinical syndrome classically consists of a fever, rash, and eschar, but scrub typhus also commonly presents as an undifferentiated fever that requires laboratory confirmation of the diagnosis, usually by indirect fluorescent antibody (IFA) assay. We discuss the limitations of IFA, debate the value of other methods based on antigen detection and nucleic acid amplification, and outline recommendations for future study. Copyright © 2010 by The American Society of Tropical Medicine and Hygiene.

Mai LQ, Wertheim HFL, Duong TN, van Doorn HR, Hien NT, Horby P. 2010. A Community Cluster of Oseltamivir-Resistant Cases of 2009 H1N1 Influenza New England Journal of Medicine, 362 (1), pp. 86-87. | Citations: 43 (Scopus) | Read more

Kaur H, Green MD, Hostetler DM, Fernández FM, Newton PN. 2010. Antimalarial drug quality: methods to detect suspect drugs Therapy, 7 (1), pp. 49-57. | Citations: 23 (Scopus) | Show Abstract | Read more

Malaria is a major public health problem in the endemic countries of Africa, Asia and Latin America. Poor quality antimalarials are of major, but neglected, concern in the control of Plasmodium falciparum malaria. They cause treatment failure and economic loss, and engender drug resistance and loss of confidence in health systems. The emergence of resistance to the artemisinin derivatives in Asia bodes ill for malaria control in Africa, and strenuous efforts are needed to improve the quality of the world's supply of antimalarials. This article reviews the problem and discusses methods available to determine the quality of antimalarials. © 2010 Future Medicine Ltd.

Aslam A, Chan H, Ogg GS, Warrell DA, Misbah S. 2010. Tracking Antigen-Specific T-Cells during Clinical Tolerance Induction in Humans PLoS ONE, 5 (6), | Citations: 3 (Scopus) | Show Abstract | Read more

Allergen immunotherapy presents an opportunity to define mechanisms of induction of clinical tolerance in humans. Significant progress has been made in our understanding of changes in T cell responses during immunotherapy, but existing work has largely been based on functional T cell assays. HLA-peptide-tetrameric complexes allow the tracking of antigen-specific T-cell populations based on the presence of specific T-cell receptors and when combined with functional assays allow a closer assessment of the potential roles of T-cell anergy and clonotype evolution. We sought to develop tools to facilitate tracking of antigen-specific T-cell populations during wasp-venom immunotherapy in people with wasp-venom allergy. We first defined dominant immunogenic regions within Ves v 5, a constituent of wasp venom that is known to represent a target antigen for T-cells. We next identified HLA-DRB1*1501 restricted epitopes and used HLA class II tetrameric complexes alongside cytokine responses to Ves v 5 to track T-cell responses during immunotherapy. In contrast to previous reports, we show that there was a significant initial induction of IL-4 producing antigen-specific T-cells within the first 3-5 weeks of immunotherapy which was followed by reduction of circulating effector antigen-specific T-cells despite escalation of wasp-venom dosage. However, there was sustained induction of IL-10-producing and FOXP3 positive antigen-specific T cells. We observed that these IL-10 producing cells could share a common precursor with IL-4-producing T cells specific for the same epitope. Clinical tolerance induction in humans is associated with dynamic changes in frequencies of antigenspecific T-cells, with a marked loss of IL-4-producing T-cells and the acquisition of IL-10-producing and FOXP3-positive antigen-specific CD4+ T-cells that can derive from a common shared precursor to pre-treatment effector T-cells. The development of new approaches to track antigen specific T-cell responses during immunotherapy can provide novel insights into mechanisms of tolerance induction in humans and identify new potential treatment targets. © 2010 Aslam et al.

Hang VTT, Holmes EC, Veasna D, Quy NT, Hien TT, Quail M, Churcher C, Parkhill J, Cardosa J, Farrar J et al. 2010. Emergence of the Asian 1 genotype of dengue Virus serotype 2 in viet Nam: in vivo fitness advantage and lineage replacement in South-East Asia PLoS Neglected Tropical Diseases, 4 (7), | Citations: 88 (Scopus) | Show Abstract | Read more

A better description of the extent and structure of genetic diversity in dengue virus (DENV) in endemic settings is central to its eventual control. To this end we determined the complete coding region sequence of 187 DENV-2 genomes and 68 E genes from viruses sampled from Vietnamese patients between 1995 and 2009. Strikingly, an episode of genotype replacement was observed, with Asian 1 lineage viruses entirely displacing the previously dominant Asian/American lineage viruses. This genotype replacement event also seems to have occurred within DENV- 2 in Thailand and Cambodia, suggestive of a major difference in viral fitness. To determine the cause of this major evolutionary event we compared both the infectivity of the Asian 1 and Asian/American genotypes in mosquitoes and their viraemia levels in humans. Although there was little difference in infectivity in mosquitoes, we observed significantly higher plasma viraemia levels in paediatric patients infected with Asian 1 lineage viruses relative to Asian/ American viruses, a phenotype that is predicted to result in a higher probability of human-to-mosquito transmission. These results provide a mechanistic basis to a marked change in the genetic structure of DENV-2 and more broadly underscore that an understanding of DENV evolutionary dynamics can inform the development of vaccines and antiviral drugs. © 2010 Ty Hang et al.

Karkey A, Arjyal A, Anders KL, Boni MF, Dongol S, Koirala S, My PVT, Nga TVT, Clements ACA, Holt KE et al. 2010. The burden and characteristics of enteric fever at a healthcare facility in a densely populated area of Kathmandu. PLoS One, 5 (11), pp. e13988. | Citations: 30 (Scopus) | Show Abstract | Read more

Enteric fever, caused by Salmonella enterica serovars Typhi and Paratyphi A (S. Typhi and S. Paratyphi A) remains a major public health problem in many settings. The disease is limited to locations with poor sanitation which facilitates the transmission of the infecting organisms. Efficacious and inexpensive vaccines are available for S. Typhi, yet are not commonly deployed to control the disease. Lack of vaccination is due partly to uncertainty of the disease burden arising from a paucity of epidemiological information in key locations. We have collected and analyzed data from 3,898 cases of blood culture-confirmed enteric fever from Patan Hospital in Lalitpur Sub-Metropolitan City (LSMC), between June 2005 and May 2009. Demographic data was available for a subset of these patients (n = 527) that were resident in LSMC and who were enrolled in trials. We show a considerable burden of enteric fever caused by S. Typhi (2,672; 68.5%) and S. Paratyphi A (1,226; 31.5%) at this Hospital over a four year period, which correlate with seasonal fluctuations in rainfall. We found that local population density was not related to incidence and we identified a focus of infections in the east of LSMC. With data from patients resident in LSMC we found that the median age of those with S. Typhi (16 years) was significantly less than S. Paratyphi A (20 years) and that males aged 15 to 25 were disproportionately infected. Our findings provide a snapshot into the epidemiological patterns of enteric fever in Kathmandu. The uneven distribution of enteric fever patients within the population suggests local variation in risk factors, such as contaminated drinking water. These findings are important for initiating a vaccination scheme and improvements in sanitation. We suggest any such intervention should be implemented throughout the LSMC area.

Mwaniki MK, Gatakaa HW, Mturi FN, Chesaro CR, Chuma JM, Peshu NM, Mason L, Kager P, Marsh K, English M et al. 2010. An increase in the burden of neonatal admissions to a rural district hospital in Kenya over 19 years. BMC Public Health, 10 (1), pp. 591. | Citations: 17 (Scopus) | Show Abstract | Read more

BACKGROUND: Most of the global neonatal deaths occur in developing nations, mostly in rural homes. Many of the newborns who receive formal medical care are treated in rural district hospitals and other peripheral health centres. However there are no published studies demonstrating trends in neonatal admissions and outcome in rural health care facilities in resource poor regions. Such information is critical in planning public health interventions. In this study we therefore aimed at describing the pattern of neonatal admissions to a Kenyan rural district hospital and their outcome over a 19 year period, examining clinical indicators of inpatient neonatal mortality and also trends in utilization of a rural hospital for deliveries. METHODS: Prospectively collected data on neonates is compared to non-neonatal paediatric (≤ 5 years old) admissions and deliveries' in the maternity unit at Kilifi District Hospital from January 1(st) 1990 up to December 31(st) 2008, to document the pattern of neonatal admissions, deliveries and changes in inpatient deaths. Trends were examined using time series models with likelihood ratios utilised to identify indicators of inpatient neonatal death. RESULTS: The proportion of neonatal admissions of the total paediatric ≤ 5 years admissions significantly increased from 11% in 1990 to 20% by 2008 (trend 0.83 (95% confidence interval 0.45-1.21). Most of the increase in burden was from neonates born in hospital and very young neonates aged < 7 days. Hospital deliveries also increased significantly. Clinical diagnoses of neonatal sepsis, prematurity, neonatal jaundice, neonatal encephalopathy, tetanus and neonatal meningitis accounted for over 75% of the inpatient neonatal admissions. Inpatient case fatality for all ≤ 5 years declined significantly over the 19 years. However, neonatal deaths comprised 33% of all inpatient death among children aged ≤ 5 years in 1990, this increased to 55% by 2008. Tetanus 256/390 (67%), prematurity 554/1,280(43%) and neonatal encephalopathy 253/778(33%) had the highest case fatality. A combination of six indicators: irregular respiration, oxygen saturation of <90%, pallor, neck stiffness, weight < 1.5 kg, and abnormally elevated blood glucose > 7 mmol/l predicted inpatient neonatal death with a sensitivity of 81% and a specificity of 68%. CONCLUSIONS: There is clear evidence of increasing burden in neonatal admissions at a rural district hospital in contrast to reducing numbers of non-neonatal paediatrics' admissions aged ≤ 5 years. Though the inpatient case fatality for all admissions aged ≤ 5 years declined significantly, neonates now comprise close to 60% of all inpatient deaths. Simple indicators may identify neonates at risk of death.

Tran TH, Nguyen TD, Nguyen TT, Ninh TT, Tran NB, Nguyen VM, Tran TT, Cao TT, Pham VM, Nguyen TC et al. 2010. A randomised trial evaluating the safety and immunogenicity of the novel single oral dose typhoid vaccine M01ZH09 in healthy Vietnamese children. PloS one, 5 (7), | Citations: 4 (Scopus) | Show Abstract | Read more

BACKGROUND: The emergence of drug resistant typhoid fever is a major public health problem, especially in Asia. An oral single dose typhoid vaccine would have major advantages. M01ZH09 is a live oral single dose candidate typhoid vaccine containing Salmonella enterica serovar Typhi (Ty2 aroC(-)ssaV(-)) ZH9 with two independently attenuating deletions. Studies in healthy adults demonstrated immunogenicity and an acceptable safety profile. OBJECTIVES: We conducted a randomised placebo controlled, single-blind trial to evaluate the safety and immunogenicity of M01ZH09 in healthy Vietnamese children aged 5 to 14 years. METHODS: Subjects were randomly assigned to receive either a nominal dose of 5x10(9) CFU of M01ZH09 or placebo and were followed up for 28 days. The primary safety outcome was the proportion of subjects with any adverse event attributed to M01ZH09. The primary immunogenicity endpoint was the proportion of subjects who showed a positive immune response to M01ZH09 in the Salmonella Typhi lipopolysaccharide (LPS) specific serum IgA and IgG ELISA. PRINCIPAL FINDINGS: One hundred and fifty-one children were enrolled, 101 subjects received M01ZH09 and 50 subjects received placebo. An intention to treat analysis was conducted. There were no serious adverse events and no bacteraemias. In the M01ZH09 group, 26 (26%; 95% CI, 18-5%) of 101 subjects experienced adverse events compared to 11 (22%; 95% CI, 12-36%) of 50 subjects in the placebo group (odds ratio (OR) [95%CI] = 1.23 [0.550-2.747]; p = 0.691). Faecal shedding of S. Typhi (Ty2 aroC(-)ssaV(-)) ZH9 was detected in 51 (51%; 95% CI, 41-61%) of 100 M01ZH09 subjects. No shedding was detected beyond day 3. A positive immune response, defined as 70% increase (1.7 fold change) in LPS specific serum IgG (day 14 or 28) and/or 50% increase (1.5 fold change) in LPS specific serum IgA (day 7 or 14) from baseline was detected in 98 (97%; 95% CI, 92-99%) of 101 M01ZH09 recipients and 8 (16%; 95% CI, 7-29%) of 50 placebo recipients. Twenty-eight (100%; 95% CI, 88-100%) of 28 vaccine recipients who were evaluated in the LPS specific IgA ELISPOT assay showed a positive response compared to none of the 14 placebo recipients tested. CONCLUSIONS: This was the first phase II trial of a novel oral candidate typhoid vaccine in children in an endemic country. M01ZH09 had an appropriate safety profile and was immunogenic in children. TRIAL REGISTRATION: Controlled-trials.com ISRCTN91111837.

Youssef RM, Alegana VA, Amran J, Noor AM, Snow RW. 2010. Fever prevalence and management among three rural communities in the North West Zone, Somalia Eastern Mediterranean Health Journal, 16 (6), pp. 460-466. | Citations: 3 (Scopus) | Show Abstract

Between March and August 2008 we undertook 2 cross-sectional surveys among 1375 residents of 3 randomly selected villages in the district of Gebiley in the North-West Zone, Somalia. We investigated for the presence of malaria infection and the period prevalence of self-reported fever 14 days prior to both surveys. All blood samples examined were negative for both species of Plasmodium. The period prevalence of 14-day fevers was 4.8% in March and 0.6% in August; the majority of fevers (84.4%) were associated with other symptoms including cough, running nose and sore throat; 48/64 cases had resolved by the day of interview (mean duration 5.4 days). Only 18 (37.5%) fever cases were managed at a formal health care facility: 7 within 24 hours and 10 within 24-72 hours of onset. None of the fevers were investigated for malaria; they were treated with antibiotics, antipyretics and vitamins.

Feachem RGA, Phillips AA, Targett GA, Snow RW. 2010. Call to action: priorities for malaria elimination. Lancet, 376 (9752), pp. 1517-1521. | Citations: 68 (Scopus) | Read more

Feachem RGA, Phillips AA, Hwang J, Cotter C, Wielgosz B, Greenwood BM, Sabot O, Rodriguez MH, Abeyasinghe RR, Ghebreyesus TA, Snow RW. 2010. Shrinking the malaria map: progress and prospects The Lancet, 376 (9752), pp. 1566-1578. | Citations: 240 (Scopus) | Show Abstract | Read more

In the past 150 years, roughly half of the countries in the world eliminated malaria. Nowadays, there are 99 endemic countries - 67 are controlling malaria and 32 are pursuing an elimination strategy. This four-part Series presents evidence about the technical, operational, and financial dimensions of malaria elimination. The first paper in this Series reviews definitions of elimination and the state that precedes it: controlled low-endemic malaria. Feasibility assessments are described as a crucial step for a country transitioning from controlled low-endemic malaria to elimination. Characteristics of the 32 malaria-eliminating countries are presented, and contrasted with countries that pursued elimination in the past. Challenges and risks of elimination are presented, including Plasmodium vivax, resistance in the parasite and mosquito populations, and potential resurgence if investment and vigilance decrease. The benefits of elimination are outlined, specifically elimination as a regional and global public good. Priorities for the next decade are described. © 2010 Elsevier Ltd.

Moonen B, Cohen JM, Snow RW, Slutsker L, Drakeley C, Smith DL, Abeyasinghe RR, Rodriguez MH, Maharaj R, Tanner M, Targett G. 2010. Operational strategies to achieve and maintain malaria elimination The Lancet, 376 (9752), pp. 1592-1603. | Citations: 201 (Scopus) | Show Abstract | Read more

Present elimination strategies are based on recommendations derived during the Global Malaria Eradication Program of the 1960s. However, many countries considering elimination nowadays have high intrinsic transmission potential and, without the support of a regional campaign, have to deal with the constant threat of imported cases of the disease, emphasising the need to revisit the strategies on which contemporary elimination programmes are based. To eliminate malaria, programmes need to concentrate on identification and elimination of foci of infections through both passive and active methods of case detection. This approach needs appropriate treatment of both clinical cases and asymptomatic infections, combined with targeted vector control. Draining of infectious pools entirely will not be sufficient since they could be replenished by imported malaria. Elimination will thus additionally need identification and treatment of incoming infections before they lead to transmission, or, more realistically, embarking on regional initiatives to dry up importation at its source. © 2010 Elsevier Ltd.

Okiro EA, Alegana VA, Noor AM, Snow RW. 2010. Changing malaria intervention coverage, transmission and hospitalization in Kenya. Malar J, 9 (1), pp. 285. | Citations: 48 (Scopus) | Show Abstract | Read more

BACKGROUND: Reports of declining incidence of malaria disease burden across several countries in Africa suggest that the epidemiology of malaria across the continent is in transition. Whether this transition is directly related to the scaling of intervention coverage remains a moot point. METHODS: Paediatric admission data from eight Kenyan hospitals and their catchments have been assembled across two three-year time periods: September 2003 to August 2006 (pre-scaled intervention) and September 2006 to August 2009 (post-scaled intervention). Interrupted time series (ITS) models were developed adjusting for variations in rainfall and hospital use by surrounding communities to show changes in malaria hospitalization over the two periods. The temporal changes in factors that might explain changes in disease incidence were examined sequentially for each hospital setting, compared between hospital settings and ranked according to plausible explanatory factors. RESULTS: In six out of eight sites there was a decline in Malaria admission rates with declines between 18% and 69%. At two sites malaria admissions rates increased by 55% and 35%. Results from the ITS models indicate that before scaled intervention in September 2006, there was a significant month-to-month decline in the mean malaria admission rates at four hospitals (trend P < 0.05). At the point of scaled intervention, the estimated mean admission rates for malaria was significantly less at four sites compared to the pre-scaled period baseline. Following scaled intervention there was a significant change in the month-to-month trend in the mean malaria admission rates in some but not all of the sites. Plausibility assessment of possible drivers of change pre- versus post-scaled intervention showed inconsistent patterns however, allowing for the increase in rainfall in the second period, there is a suggestion that starting transmission intensity and the scale of change in ITN coverage might explain some but not all of the variation in effect size. At most sites where declines between observation periods were documented admission rates were changing before free mass ITN distribution and prior to the implementation of ACT across Kenya. CONCLUSION: This study provides evidence of significant within and between location heterogeneity in temporal trends of malaria disease burden. Plausible drivers for changing disease incidence suggest a complex combination of mechanisms, not easily measured retrospectively.

Dunachie SJ, Berthoud T, Keating SM, Hill AVS, Fletcher HA. 2010. MIG and the regulatory cytokines IL-10 and TGF-β1 correlate with malaria vaccine immunogenicity and efficacy. PLoS One, 5 (9), pp. e12557. | Citations: 12 (Web of Science Lite) | Show Abstract | Read more

Malaria remains one of the world's greatest killers and a vaccine is urgently required. There are no established correlates of protection against malaria either for natural immunity to the disease or for immunity conferred by candidate malaria vaccines. The RTS,S/AS02A vaccine offers significant partial efficacy against malaria.mRNA expression of five key cytokines interferon-gamma (IFN-γ), monokine induced by gamma (MIG), interleukin-10 (IL-10), transforming growth factor-β (TGF-β) and forkhead box P3 (FoxP3) in peripheral blood mononuclear cells were measured by real-time RT-PCR before and after vaccination with RTS,S/AS02A and Modified Vaccinia virus Ankara encoding the circumsporozoite protein (MVA-CS) in healthy malaria-naïve adult volunteers. The only significant change was in IFN-γ mRNA expression, which was increased seven days after vaccination (P  =  0.04). Expression of MIG mRNA seven days after vaccination correlated inversely with time to detection of parasites by blood film in an experimental sporozoite challenge (r = 0.94 P  =  0.005). An inverse relationship was seen between both TGF-β1 and IL-10 mRNA at baseline and the anti-circumsporozoite IgG antibody response (r  =  -0.644 P  =  0.022 and r =  -0.554 P = 0.031 respectively). This study demonstrates the potential for MIG expression as a correlate of protection against malaria. Baseline levels of the regulatory cytokines TGF-β and IL-10 inversely correlated with antibody levels post vaccination and warrant further studies to improve understanding of individual differences in response to vaccination.

Boel M, Carrara VI, Rijken M, Proux S, Nacher M, Pimanpanarak M, Paw MK, Moo O, Gay H, Bailey W et al. 2010. Complex Interactions between soil-transmitted helminths and malaria in pregnant women on the Thai-Burmese border. PLoS Negl Trop Dis, 4 (11), pp. e887. | Citations: 45 (Scopus) | Show Abstract | Read more

BACKGROUND: Deworming is recommended by the WHO in girls and pregnant and lactating women to reduce anaemia in areas where hookworm and anaemia are common. There is conflicting evidence on the harm and the benefits of intestinal geohelminth infections on the incidence and severity of malaria, and consequently on the risks and benefits of deworming in malaria affected populations. We examined the association between geohelminths and malaria in pregnancy on the Thai-Burmese border. METHODOLOGY: Routine antenatal care (ANC) included active detection of malaria (weekly blood smear) and anaemia (second weekly haematocrit) and systematic reporting of birth outcomes. In 1996 stool samples were collected in cross sectional surveys from women attending the ANCs. This was repeated in 2007 when malaria incidence had reduced considerably. The relationship between geohelminth infection and the progress and outcome of pregnancy was assessed. PRINCIPAL FINDINGS: Stool sample examination (339 in 1996, 490 in 2007) detected a high prevalence of geohelminths 70% (578/829), including hookworm (42.8% (355)), A. lumbricoides (34.4% (285)) and T.trichuria (31.4% (250)) alone or in combination. A lower proportion of women (829) had mild (21.8% (181)) or severe (0.2% (2)) anaemia, or malaria 22.4% (186) (P.vivax monoinfection 53.3% (101/186)). A. lumbricoides infection was associated with a significantly decreased risk of malaria (any species) (AOR: 0.43, 95% CI: 0.23-0.84) and P.vivax malaria (AOR: 0.29, 95% CI: 0.11-0.79) whereas hookworm infection was associated with an increased risk of malaria (any species) (AOR: 1.66, 95% CI: 1.06-2.60) and anaemia (AOR: 2.41, 95% CI: 1.18-4.93). Hookworm was also associated with low birth weight (AOR: 1.81, 95% CI: 1.02-3.23). CONCLUSION/SIGNIFICANCE: A. lumbricoides and hookworm appear to have contrary associations with malaria in pregnancy.

McGready R, Ashley EA, Wuthiekanun V, Tan SO, Pimanpanarak M, Viladpai-Nguen SJ, Jesadapanpong W, Blacksell SD, Peacock SJ, Paris DH et al. 2010. Arthropod borne disease: the leading cause of fever in pregnancy on the Thai-Burmese border. PLoS Negl Trop Dis, 4 (11), pp. e888. | Citations: 35 (Scopus) | Show Abstract | Read more

BACKGROUND: Fever in pregnancy is dangerous for both mother and foetus. In the 1980's malaria was the leading cause of death in pregnant women in refugee camps on the Thai-Burmese border. Artemisinin combination therapy has significantly reduced the incidence of malaria in the population. The remaining causes of fever in pregnancy are not well documented. METHODOLOGY: Pregnant women attending antenatal care, where weekly screening for malaria is routine, were invited to have a comprehensive clinical and laboratory screen if they had fever. Women were admitted to hospital, treated and followed up weekly until delivery. A convalescent serum was collected on day 21. Delivery outcomes were recorded. PRINCIPAL FINDINGS: Febrile episodes (n = 438) occurred in 5.0% (409/8,117) of pregnant women attending antenatal clinics from 7-Jan-2004 to 17-May-2006. The main cause was malaria in 55.5% (227/409). A cohort of 203 (49.6% of 409) women had detailed fever investigations and follow up. Arthropod-borne (malaria, rickettsial infections, and dengue) and zoonotic disease (leptospirosis) accounted for nearly half of all febrile illnesses, 47.3% (96/203). Coinfection was observed in 3.9% (8/203) of women, mostly malaria and rickettsia. Pyelonephritis, 19.7% (40/203), was also a common cause of fever. Once malaria, pyelonephritis and acute respiratory illness are excluded by microscopy and/or clinical findings, one-third of the remaining febrile infections will be caused by rickettsia or leptospirosis. Scrub and murine typhus were associated with poor pregnancy outcomes including stillbirth and low birth weight. One woman died (no positive laboratory tests). CONCLUSION/SIGNIFICANCE: Malaria remains the leading cause of fever in pregnancy on the Thai-Burmese border. Scrub and murine typhus were also important causes of fever associated with poor pregnancy outcomes. Febrile pregnant women on the Thai-Burmese border who do not have malaria, pyelonephritis or respiratory tract infection should be treated with azithromycin, effective for typhus and leptospirosis.

Wikramaratna PS, Simmons CP, Gupta S, Recker M. 2010. The effects of tertiary and quaternary infections on the epidemiology of dengue. PLoS One, 5 (8), pp. e12347. | Citations: 34 (Scopus) | Show Abstract | Read more

The epidemiology of dengue is characterised by irregular epidemic outbreaks and desynchronised dynamics of its four co-circulating virus serotypes. Whilst infection by one serotype appears to convey life-long protection to homologous infection, it is believed to be a risk factor for severe disease manifestations upon secondary, heterologous infection due to the phenomenon of Antibody-Dependent Enhancement (ADE). Subsequent clinical infections are rarely reported and, since the majority of dengue infections are generally asymptomatic, it is not clear if and to what degree tertiary or quaternary infections contribute to dengue epidemiology. Here we investigate the effect of third and subsequent infections on the transmission dynamics of dengue and show that although the qualitative patterns are largely equivalent, the system more readily exhibits the desynchronised serotype oscillations and multi-annual epidemic outbreaks upon their inclusion. More importantly, permitting third and fourth infections significantly increases the force of infection without resorting to high basic reproductive numbers. Realistic age-prevalent patterns and seroconversion rates are therefore easier reconciled with a low value of dengue's transmission potential if allowing for more than two infections; this should have important consequences for dengue control and intervention measures.

Gitonga CW, Karanja PN, Kihara J, Mwanje M, Juma E, Snow RW, Noor AM, Brooker S. 2010. Implementing school malaria surveys in Kenya: towards a national surveillance system. Malar J, 9 (1), pp. 306. | Citations: 37 (Scopus) | Show Abstract | Read more

OBJECTIVE: To design and implement surveys of malaria infection and coverage of malaria control interventions among school children in Kenya in order to contribute towards a nationwide assessment of malaria. METHODS: The country was stratified into distinct malaria transmission zones based on a malaria risk map and 480 schools were visited between October 2008 and March 2010. Surveys were conducted in two phases: an initial opportunistic phase whereby schools were selected for other research purposes; and a second phase whereby schools were purposively selected to provide adequate spatial representation across the country. Consent for participation was based on passive, opt-out consent rather than written, opt-in consent because of the routine, low-risk nature of the survey. All children were diagnosed for Plasmodium infection using rapid diagnostic tests, assessed for anaemia and were interviewed about mosquito net usage, recent history of illness, and socio-economic and household indicators. Children's responses were entered electronically in the school and data transmitted nightly to Nairobi using a mobile phone modem connection. RDT positive results were corrected by microscopy and all results were adjusted for clustering using random effect regression modelling. RESULTS: 49,975 children in 480 schools were sampled, at an estimated cost of US$ 1,116 per school. The overall prevalence of malaria and anaemia was 4.3% and 14.1%, respectively, and 19.0% of children reported using an insecticide-treated net (ITN). The prevalence of infection showed marked variation across the country, with prevalence being highest in Western and Nyanza provinces, and lowest in Central, North Eastern and Eastern provinces. Nationally, 2.3% of schools had reported ITN use >60%, and low reported ITN use was a particular problem in Western and Nyanza provinces. Few schools reported having malaria health education materials or ongoing malaria control activities. CONCLUSION: School malaria surveys provide a rapid, cheap and sustainable approach to malaria surveillance which can complement household surveys, and in Kenya, show that large areas of the country do not merit any direct school-based control, but school-based interventions, coupled with strengthened community-based strategies, are warranted in western and coastal Kenya. The results also provide detailed baseline data to inform evaluation of school-based malaria control in Kenya.

Takeuchi R, Lawpoolsri S, Imwong M, Kobayashi J, Kaewkungwal J, Pukrittayakamee S, Puangsa-art S, Thanyavanich N, Maneeboonyang W, Day NPJ, Singhasivanon P. 2010. Directly-observed therapy (DOT) for the radical 14-day primaquine treatment of Plasmodium vivax malaria on the Thai-Myanmar border. Malar J, 9 (1), pp. 308. | Citations: 31 (Scopus) | Show Abstract | Read more

BACKGROUND: Plasmodium vivax has a dormant hepatic stage, called the hypnozoite, which can cause relapse months after the initial attack. For 50 years, primaquine has been used as a hypnozoitocide to radically cure P. vivax infection, but major concerns remain regarding the side-effects of the drug and adherence to the 14-day regimen. This study examined the effectiveness of using the directly-observed therapy (DOT) method for the radical treatment of P. vivax malaria infection, to prevent reappearance of the parasite within the 90-day follow-up period. Other potential risk factors for the reappearance of P. vivax were also explored. METHODS: A randomized trial was conducted from May 2007 to January 2009 in a low malaria transmission area along the Thai-Myanmar border. Patients aged ≥ 3 years diagnosed with P. vivax by microscopy, were recruited. All patients were treated with the national standard regimen of chloroquine for three days followed by primaquine for 14 days. Patients were randomized to receive DOT or self-administered therapy (SAT). All patients were followed for three months to check for any reappearance of P. vivax. RESULTS: Of the 216 patients enrolled, 109 were randomized to DOT and 107 to SAT. All patients recovered without serious adverse effects. The vivax reappearance rate was significantly lower in the DOT group than the SAT group (3.4/10,000 person-days vs. 13.5/10,000 person-days, p = 0.021). Factors related to the reappearance of vivax malaria included inadequate total primaquine dosage received (< 2.75 mg/kg), duration of fever ≤ 2 days before initiation of treatment, parasite count on admission ≥ 10,000/µl, multiple P. vivax-genotype infection, and presence of P. falciparum infection during the follow-up period. CONCLUSIONS: Adherence to the 14-day primaquine regimen is important for the radical cure of P. vivax malaria infection. Implementation of DOT reduces the reappearance rate of the parasite, and may subsequently decrease P. vivax transmission in the area.

Dondorp AM, Fanello CI, Hendriksen IC, Gomes E, Seni A, Chhaganlal KD, Bojang K, Olaosebikan R, Anunobi N, Maitland K et al. 2010. Artesunate versus quinine in the treatment of severe falciparum malaria in African children (AQUAMAT): An open-label, randomised trial The Lancet, 376 (9753), pp. 1647-1657. | Citations: 422 (Scopus) | Show Abstract | Read more

Severe malaria is a major cause of childhood death and often the main reason for paediatric hospital admission in sub-Saharan Africa. Quinine is still the established treatment of choice, although evidence from Asia suggests that artesunate is associated with a lower mortality. We compared parenteral treatment with either artesunate or quinine in African children with severe malaria. This open-label, randomised trial was undertaken in 11 centres in nine African countries. Children ( < 15 years) with severe falciparum malaria were randomly assigned to parenteral artesunate or parenteral quinine. Randomisation was in blocks of 20, with study numbers corresponding to treatment allocations kept inside opaque sealed paper envelopes. The trial was open label at each site, and none of the investigators or trialists, apart from for the trial statistician, had access to the summaries of treatment allocations. The primary outcome measure was in-hospital mortality, analysed by intention to treat. This trial is registered, number ISRCTN50258054. 5425 children were enrolled; 2712 were assigned to artesunate and 2713 to quinine. All patients were analysed for the primary outcome. 230 (8·5) patients assigned to artesunate treatment died compared with 297 (10·9) assigned to quinine treatment (odds ratio [OR] stratified for study site 0·75, 95 CI 0·63-0·90; relative reduction 22·5, 95 CI 8·1-36·9; p=0·0022). Incidence of neurological sequelae did not differ significantly between groups, but the development of coma (65/1832 [3·5] with artesunate vs 91/1768 [5·1] with quinine; OR 0·69 95 CI 0·49-0·95; p=0·0231), convulsions (224/2712 [8·3] vs 273/2713 [10·1] ; OR 0·80, 0·66-0·97; p=0·0199), and deterioration of the coma score (166/2712 [6·1] vs 208/2713 [7·7] ; OR 0·78, 0·64-0·97; p=0·0245) were all significantly less frequent in artesunate recipients than in quinine recipients. Post-treatment hypoglycaemia was also less frequent in patients assigned to artesunate than in those assigned to quinine (48/2712 [1·8] vs 75/2713 [2·8] ; OR 0·63, 0·43-0·91; p=0·0134). Artesunate was well tolerated, with no serious drug-related adverse effects. Artesunate substantially reduces mortality in African children with severe malaria. These data, together with a meta-analysis of all trials comparing artesunate and quinine, strongly suggest that parenteral artesunate should replace quinine as the treatment of choice for severe falciparum malaria worldwide. The Wellcome Trust. © 2010 Elsevier Ltd.

Monatrakul P, Mungthin M, Dondorp AM, Krudsood S, Udomsangpetch R, Wilairatana P, White NJ, Chotivanich K. 2010. Modulating effects of plasma containing anti-malarial antibodies on in vitro anti-malarial drug susceptibility in Plasmodium falciparum. Malar J, 9 (1), pp. 326. | Citations: 4 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: The efficacy of anti-malarial drugs is determined by the level of parasite susceptibility, anti-malarial drug bioavailability and pharmacokinetics, and host factors including immunity. Host immunity improves the in vivo therapeutic efficacy of anti-malarial drugs, but the mechanism and magnitude of this effect has not been characterized. This study characterized the effects of 'immune' plasma to Plasmodium falciparumon the in vitro susceptibility of P. falciparum to anti-malarial drugs. METHODS: Titres of antibodies against blood stage antigens (mainly the ring-infected erythrocyte surface antigen [RESA]) were measured in plasma samples obtained from Thai patients with acute falciparum malaria. 'Immune' plasma was selected and its effects on in vitro parasite growth and multiplication of the Thai P. falciparum laboratory strain TM267 were assessed by light microscopy. The in vitro susceptibility to quinine and artesunate was then determined in the presence and absence of 'immune' plasma using the 3H-hypoxanthine uptake inhibition method. Drug susceptibility was expressed as the concentrations causing 50% and 90% inhibition (IC50 and IC90), of 3H-hypoxanthine uptake. RESULTS: Incubation with 'immune' plasma reduced parasite maturation and decreased parasite multiplication in a dose dependent manner. 3H-hypoxanthine incorporation after incubation with 'immune' plasma was decreased significantly compared to controls (median [range]; 181.5 [0 to 3,269] cpm versus 1,222.5 [388 to 5,932] cpm) (p= 0.001). As a result 'immune' plasma reduced apparent susceptibility to quinine substantially; median (range) IC50 6.4 (0.5 to 23.8) ng/ml versus 221.5 (174.4 to 250.4) ng/ml (p = 0.02), and also had a borderline effect on artesunate susceptibility; IC50 0.2 (0.02 to 0.3) ng/ml versus 0.8 (0.2 to 2.3) ng/ml (p = 0.08). Effects were greatest at low concentrations, changing the shape of the concentration-effect relationship. IC90 values were not significantly affected; median (range) IC90 448.0 (65 to > 500) ng/ml versus 368.8 (261 to 501) ng/ml for quinine (p > 0.05) and 17.0 (0.1 to 29.5) ng/ml versus 7.6 (2.3 to 19.5) ng/ml for artesunate (p = 0.4). CONCLUSIONS: 'Immune' plasma containing anti-malarial antibodies inhibits parasite development and multiplication and increases apparent in vitro anti-malarial drug susceptibility of P. falciparum. The IC90 was much less affected than the IC50 measurement.

Minetti A, Camelique O, Hsa Thaw K, Thi S, Swaddiwudhipong W, Hewison C, Pinoges L, Bonnet M, Guerin PJ. 2010. Tuberculosis treatment in a refugee and migrant population: 20 years of experience on the Thai-Burmese border. Int J Tuberc Lung Dis, 14 (12), pp. 1589-1595. | Citations: 12 (Scopus) | Show Abstract

SETTING: Although tuberculosis (TB) is a curable disease, it remains a major global health problem and an important cause of morbidity and mortality among vulnerable populations, including refugees and migrants. OBJECTIVE: To describe results and experiences over 20 years at a TB programme in refugee camps on the Thai-Burmese border in Tak Province, Thailand, and to identify risk factors associated with adverse outcomes (e.g., default, failure, death). DESIGN: Retrospective review of routine records of 2425 patients admitted for TB treatment in the Mae La TB programme between May 1987 and December 2005. RESULTS: TB cases notified among refugees decreased over 20 years. Among patients treated with a first-, second- or third-line regimen, 77.5% had a successful outcome, 13.5% defaulted, 7.6% died and 1.3% failed treatment. Multivariate analysis for new cases showed higher likelihood of adverse outcomes for patients who were Burmese migrants or Thai villagers, male, aged >15 years or with smear-negative pulmonary TB. CONCLUSION: These findings suggest that treatment outcomes depend on the programme's capacity to respond to specific patients' constraints. High-risk groups, such as migrant populations, need a patient-centred approach, and specific, innovative strategies have to be developed based on the needs of the most vulnerable and marginalised populations.

Warrell DA, Theakston RDG, Wuester W. 2010. Destruction of the collection of reptiles and arthropods at Butantan Institute: a view from the United Kingdom JOURNAL OF VENOMOUS ANIMALS AND TOXINS INCLUDING TROPICAL DISEASES, 16 (4), pp. 534-536. | Citations: 7 (Scopus)

Mwaniki MK, Talbert AW, Mturi FN, Berkley JA, Kager P, Marsh K, Newton CR. 2010. Congenital and neonatal malaria in a rural Kenyan district hospital: an eight-year analysis. Malar J, 9 (1), pp. 313. | Citations: 18 (Scopus) | Show Abstract | Read more

BACKGROUND: Malaria remains a significant burden in sub-Saharan Africa. However, data on burden of congenital and neonatal malaria is scarce and contradictory, with some recent studies reporting a high burden. Using prospectively collected data on neonatal admissions to a rural district hospital in a region of stable malaria endemicity in Kenya, the prevalence of congenital and neonatal malaria was described. METHODS: From 1st January 2002 to 31st December 2009, admission and discharge information on all neonates admitted to Kilifi District Hospital was collected. At admission, blood was also drawn for routine investigations, which included a full blood count, blood culture and blood slide for malaria parasites. RESULTS: Of the 5,114 neonates admitted during the eight-year surveillance period, blood slide for malaria parasites was performed in 4,790 (93.7%). 18 (0.35%) neonates with Plasmodium falciparum malaria parasitaemia, of whom 11 were admitted within the first week of life and thus classified as congenital parasitaemia, were identified. 7/18 (39%) had fever. Parasite densities were low, ≤50 per μl in 14 cases. The presence of parasitaemia was associated with low haemoglobin (Hb) of <10 g/dl (χ² 10.9 P = 0.001). The case fatality rate of those with and without parasitaemia was similar. Plasmodium falciparum parasitaemia was identified as the cause of symptoms in four neonates. CONCLUSION: Congenital and neonatal malaria are rare in this malaria endemic region. Performing a blood slide for malaria parasites among sick neonates in malaria endemic regions is advisable. This study does not support routine treatment with anti-malarial drugs among admitted neonates with or without fever even in a malaria endemic region.

Baird JK. 2010. Eliminating malaria - All of them The Lancet, 376 (9756), pp. 1883-1885. | Citations: 36 (Scopus) | Read more

Hay SI, Gething PW, Snow RW. 2010. India's invisible malaria burden The Lancet, 376 (9754), pp. 1716-1717. | Citations: 32 (Scopus) | Read more

Mirghani SE, Nour BYM, Bushra SM, Hassan I, Snow RW, Noor AM. 2010. The spatial-temporal clustering of Plasmodium falciparum infection over eleven years in Gezira State, The Sudan Malaria Journal, 9 (Suppl 2), pp. P65-P65. | Citations: 11 (Scopus) | Read more

Tandhavanant S, Thanwisai A, Limmathurotsakul D, Korbsrisate S, Day NP, Peacock SJ, Chantratita N. 2010. Effect of colony morphology variation of Burkholderia pseudomallei on intracellular survival and resistance to antimicrobial environments in human macrophages in vitro. BMC Microbiol, 10 (1), pp. 303. | Citations: 21 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Primary diagnostic cultures from patients with melioidosis demonstrate variation in colony morphology of the causative organism, Burkholderia pseudomallei. Variable morphology is associated with changes in the expression of a range of putative virulence factors. This study investigated the effect of B. pseudomallei colony variation on survival in the human macrophage cell line U937 and under laboratory conditions simulating conditions within the macrophage milieu. Isogenic colony morphology types II and III were generated from 5 parental type I B. pseudomallei isolates using nutritional limitation. Survival of types II and III were compared with type I for all assays. RESULTS: Morphotype was associated with survival in the presence of H2O2 and antimicrobial peptide LL-37, but not with susceptibility to acid, acidified sodium nitrite, or resistance to lysozyme, lactoferrin, human neutrophil peptide-1 or human beta defensin-2. Incubation under anaerobic conditions was a strong driver for switching of type III to an alternative morphotype. Differences were noted in the survival and replication of the three types following uptake by human macrophages, but marked strain-to strain-variability was observed. Uptake of type III alone was associated with colony morphology switching. CONCLUSIONS: Morphotype is associated with phenotypes that alter the ability of B. pseudomallei to survive in adverse environmental conditions.

Vallée J, Thaojaikong T, Moore CE, Phetsouvanh R, Richards AL, Souris M, Fournet F, Salem G, Gonzalez J-PJ, Newton PN. 2010. Contrasting spatial distribution and risk factors for past infection with scrub typhus and murine typhus in Vientiane City, Lao PDR. PLoS Negl Trop Dis, 4 (12), pp. e909. | Citations: 20 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: The aetiological diagnostic of fevers in Laos remains difficult due to limited laboratory diagnostic facilities. However, it has recently become apparent that both scrub and murine typhus are common causes of previous undiagnosed fever. Epidemiological data suggests that scrub typhus would be more common in rural areas and murine typhus in urban areas, but there is very little recent information on factors involved in scrub and murine typhus transmission, especially where they are sympatric - as is the case in Vientiane, the capital of the Lao PDR. METHODOLOGY AND PRINCIPAL FINDINGS: We therefore determined the frequency of IgG seropositivity against scrub typhus (Orientia tsutsugamushi) and murine typhus (Rickettsia typhi), as indices of prior exposure to these pathogens, in randomly selected adults in urban and peri-urban Vientiane City (n = 2,002, ≥35 years). Anti-scrub and murine typhus IgG were detected by ELISA assays using filter paper elutes. We validated the accuracy of ELISA of these elutes against ELISA using serum samples. The overall prevalence of scrub and murine typhus IgG antibodies was 20.3% and 20.6%, respectively. Scrub typhus seropositivity was significantly higher among adults living in the periphery (28.4%) than in the central zone (13.1%) of Vientiane. In contrast, seroprevalence of murine typhus IgG antibodies was significantly higher in the central zone (30.8%) as compared to the periphery (14.4%). In multivariate analysis, adults with a longer residence in Vientiane were at significant greater risk of past infection with murine typhus and at lower risk for scrub typhus. Those with no education, living on low incomes, living on plots of land with poor sanitary conditions, living in large households, and farmers were at higher risk of scrub typhus and those living in neighborhoods with high building density and close to markets were at greater risk for murine typhus and at lower risk of scrub typhus past infection. CONCLUSIONS: This study underscores the intense circulation of both scrub and murine typhus in Vientiane city and underlines difference in spatial distribution and risk factors involved in the transmission of these diseases.

Boni MF, de Jong MD, van Doorn HR, Holmes EC. 2010. Guidelines for identifying homologous recombination events in influenza A virus. PLoS One, 5 (5), pp. e10434. | Citations: 40 (Web of Science Lite) | Show Abstract | Read more

The rapid evolution of influenza viruses occurs both clonally and non-clonally through a variety of genetic mechanisms and selection pressures. The non-clonal evolution of influenza viruses comprises relatively frequent reassortment among gene segments and a more rarely reported process of non-homologous RNA recombination. Homologous RNA recombination within segments has been proposed as a third such mechanism, but to date the evidence for the existence of this process among influenza viruses has been both weak and controversial. As homologous recombination has not yet been demonstrated in the laboratory, supporting evidence, if it exists, may come primarily from patterns of phylogenetic incongruence observed in gene sequence data. Here, we review the necessary criteria related to laboratory procedures and sample handling, bioinformatic analysis, and the known ecology and evolution of influenza viruses that need to be met in order to confirm that a homologous recombination event occurred in the history of a set of sequences. To determine if these criteria have an effect on recombination analysis, we gathered 8307 publicly available full-length sequences of influenza A segments and divided them into those that were sequenced via the National Institutes of Health Influenza Genome Sequencing Project (IGSP) and those that were not. As sample handling and sequencing are executed to a very high standard in the IGSP, these sequences should be less likely to be exposed to contamination by other samples or by laboratory strains, and thus should not exhibit laboratory-generated signals of homologous recombination. Our analysis shows that the IGSP data set contains only two phylogenetically-supported single recombinant sequences and no recombinant clades. In marked contrast, the non-IGSP data show a very large amount of potential recombination. We conclude that the presence of false positive signals in the non-IGSP data is more likely than false negatives in the IGSP data, and that given the evidence to date, homologous recombination seems to play little or no role in the evolution of influenza A viruses.

Yu H, Liao Q, Yuan Y, Zhou L, Xiang N, Huai Y, Guo X, Zheng Y, van Doorn HR, Farrar J et al. 2010. Effectiveness of oseltamivir on disease progression and viral RNA shedding in patients with mild pandemic 2009 influenza A H1N1: opportunistic retrospective study of medical charts in China. BMJ, 341 (sep28 1), pp. c4779. | Citations: 59 (Web of Science Lite) | Show Abstract | Read more

OBJECTIVE: To describe the clinical features and effectiveness of oseltamivir on disease progression and viral RNA shedding in patients with mild pandemic 2009 influenza A(H1N1) virus infection. DESIGN: Opportunistic retrospective review of medical charts of patients with confirmed 2009 H1N1 identified through the national surveillance system in China from May to July 2009. SETTING: Under coordination of the Ministry of Health, local health departments were asked to collect medical records of confirmed patients and send them to the Chinese Centre for Disease Control and Prevention on a voluntary basis as part of the public health response. Population 1291 patients with confirmed 2009 H1N1 infection and available data for chart review. MAIN OUTCOME MEASURES: Demographic characteristics, comorbidities, symptoms and signs, laboratory tests, findings on chest radiography, antiviral treatment, duration of fever, and duration of viral RNA shedding. RESULTS: The median age of 1291 patients was 20 years (interquartile range 12-26); 701 (54%) were male. The most common symptoms were fever (820, 64%), cough (864, 67%), sore throat (425, 33%), sputum (239, 19%), and rhinorrhoea (228, 18%). Of 920 patients who underwent chest radiography, 110 (12%) had abnormal findings consistent with pneumonia. Some 983 (76%) patients were treated with oseltamivir from a median of the third day of symptoms (2-4). No patients required admission to the intensive care unit or mechanical ventilation. 2009 H1N1 was shed from one day before onset of symptoms to up to eight days after onset in most (91%) patients, with a median of 5 (3-6) days of shedding after onset. Treatment with oseltamivir significantly protected against subsequent development of radiographically confirmed pneumonia (odds ratio 0.12, 95% confidence interval 0.08 to 0.18), and treatment started within two days of symptom onset reduced the duration of fever and viral RNA shedding. CONCLUSIONS: Chinese patients with 2009 H1N1 infection predominantly presented with features of uncomplicated, self limiting acute respiratory illness. 2009 H1N1 might be shed longer than seasonal influenza virus. Treatment with oseltamivir was associated with a significantly reduced development of radiographically confirmed pneumonia and a shorter duration of fever and viral RNA shedding. Though these patients benefited from treatment, the findings should be interpreted with caution as the study was retrospective and not all patients underwent chest radiography.

Le T, Hong Chau TT, Kim Cuc NT, Si Lam P, Manh Sieu TP, Shikuma CM, Day JN. 2010. AIDS‐associated Cryptococcus neoformans and Penicillium marneffei coinfection: a therapeutic dilemma in resource‐limited settings. Clin Infect Dis, 51 (9), pp. e65-e68. | Citations: 7 (Scopus) | Show Abstract | Read more

AIDS&#x2010;associated Cryptococcus neoformans and Penicillium marneffei coinfection has not been adequately studied and poses unique therapeutic challenges in resource&#x2010;limited settings. Itraconazole poorly penetrates the central nervous system, whereas fluconazole has poor activity against P. marneffei. We prospectively report management of 1 patient and retrospectively review 7 coinfection cases from Vietnam.

Boni MF, de Jong MD, van Doorn HR, Holmes EC. 2010. Guidelines for identifying homologous recombination events in influenza A virus PLoS ONE, 5 (5), | Citations: 43 (Scopus) | Show Abstract | Read more

The rapid evolution of influenza viruses occurs both clonally and non-clonally through a variety of genetic mechanisms and selection pressures. The non-clonal evolution of influenza viruses comprises relatively frequent reassortment among gene segments and a more rarely reported process of non-homologous RNA recombination. Homologous RNA recombination within segments has been proposed as a third such mechanism, but to date the evidence for the existence of this process among influenza viruses has been both weak and controversial. As homologous recombination has not yet been demonstrated in the laboratory, supporting evidence, if it exists, may come primarily from patterns of phylogenetic incongruence observed in gene sequence data. Here, we review the necessary criteria related to laboratory procedures and sample handling, bioinformatic analysis, and the known ecology and evolution of influenza viruses that need to be met in order to confirm that a homologous recombination event occurred in the history of a set of sequences. To determine if these criteria have an effect on recombination analysis, we gathered 8307 publicly available full-length sequences of influenza A segments and divided them into those that were sequ enced via the National Institutes of Health Influenza Genome Sequencing Project (IGSP) and those that were not. As sample handling and sequencing are executed to a very high standard in the IGSP, these sequences should be less likely to be exposed to contamination by other samples or by laboratory strains, and thus should not exhibit laboratory-generated signals of homologous recombination. Our analysis shows that the IGSP data set contains only two phylogenetically-supported single recombinant sequences and no recombinant clades. In marked contrast, the non-IGSP data show a very large amount of potential recombination. We conclude that the presence of false positive signals in the non-IGSP data is more likely than false negatives in the IGSP data, and that given the evidence to date, homologous recombination seems to play little or no role in the evolution of influenza A viruses. © 2010 Boni et al.

Alvarez-Uria G, Day JN, Nasir AJ, Russell SK, Vilar FJ. 2010. Reduction in neutrophil count during hepatitis C treatment: drug toxicity or predictor of good response? Dig Dis Sci, 55 (7), pp. 2058-2062. | Citations: 3 (Scopus) | Show Abstract | Read more

BACKGROUND: Bone marrow suppression is a well-recognized toxicity of the treatment of hepatitis C virus (HCV). Reduction of the peginterferon dose because of neutropenia is common in clinical practice. However, reduction of peginterferon dose during the first weeks of HCV treatment is associated with failure to achieve sustained virological response. AIMS: The objective of this study is to investigate whether the fall of neutrophil count during hepatitis C treatment is associated with achieving sustained virological response. METHODS: We performed an observational study of patients who completed peginterferon and ribavirin treatment in an Infectious Diseases Department in Manchester, UK. RESULTS: Of the 74 patients included in the analysis, 78% had genotype 2 or 3 hepatitis C and 15% had liver cirrhosis. Sustained virological response was achieved in 78% of patients. On univariate analysis, factors related to achieving sustained virological response were younger age, genotype 2 or 3, baseline neutrophil count, and fall of neutrophil count during treatment. Multivariate analysis showed baseline neutrophil count >3.5 x 10(3) cells/mm(3) [odds ratio (OR) 5.7; 95% confidence interval (CI) 1.24-26.3] and a reduction of neutrophil count >60% (OR 4.5; 95% CI 1.03-19.9) to be independently associated with achieving sustained virological response. Neutropenia was not associated with an increased risk of infections. CONCLUSIONS: In this observational study, higher baseline neutrophil count and fall of neutrophil count during the treatment of hepatitis C was associated with achieving sustained virological response. These findings could have important implications for the monitoring and management of HCV treatment with peginterferon if they are confirmed in other studies.

Pontororing GJ, Kenangalem E, Lolong DB, Waramori G, Sandjaja, Tjitra E, Price RN, Kelly PM, Anstey NM, Ralph AP. 2010. The burden and treatment of HIV in tuberculosis patients in Papua Province, Indonesia: a prospective observational study. BMC Infect Dis, 10 (1), pp. 362. | Citations: 11 (Scopus) | Show Abstract | Read more

BACKGROUND: New diagnoses of tuberculosis (TB) present important opportunities to detect and treat HIV. Rates of HIV and TB in Indonesia's easternmost Papua Province exceed national figures, but data on co-infection rates and outcomes are lacking. We aimed to measure TB-HIV co-infection rates, examine longitudinal trends, compare management with World Health Organisation (WHO) recommendations, and document progress and outcome. METHODS: Adults with newly-diagnosed smear-positive pulmonary TB managed at the Timika TB clinic, Papua Province, were offered voluntary counselling and testing for HIV in accordance with Indonesian National Guidelines, using a point-of-care antibody test. Positive tests were confirmed with 2 further rapid tests. Study participants were assessed using clinical, bacteriological, functional and radiological measures and followed up for 6 months. RESULTS: Of 162 participants, HIV status was determined in 138 (85.2%), of whom 18 (13.0%) were HIV+. Indigenous Papuans were significantly more likely to be HIV+ than Non-Papuans (Odds Ratio [OR] 4.42, 95% confidence interval [CI] 1.38-14.23). HIV prevalence among people with TB was significantly higher than during a 2003-4 survey at the same TB clinic, and substantially higher than the Indonesian national estimate of 3%. Compared with HIV- study participants, those with TB-HIV co-infection had significantly lower exercise tolerance (median difference in 6-minute walk test: 25 m, p = 0.04), haemoglobin (mean difference: 1.3 g/dL, p = 0.002), and likelihood of cavitary disease (OR 0.35, 95% CI 0.12-1.01), and increased occurrence of pleural effusion (OR 3.60, 95% CI 1.70-7.58), higher rates of hospitalisation or death (OR 11.80, 95% CI 1.82-76.43), but no difference in the likelihood of successful 6-month treatment outcome. Adherence to WHO guidelines was limited by the absence of integration of TB and HIV services, specifically, with no on-site ART prescriber available. Only six people had CD4+ T-cell counts recorded, 11 were prescribed co-trimoxazole and 4 received ART before, during or after TB treatment, despite ART being indicated in 14 according to 2006 WHO guidelines. CONCLUSIONS: TB-HIV co-infection in southern Papua, Indonesia, is a serious emerging problem especially among the Indigenous population, and has risen rapidly in the last 5 years. Major efforts are required to incorporate new WHO recommendations on TB-HIV management into national guidelines, and support their implementation in community settings.

Berkley JA, Munywoki P, Nokes DJ. 2010. In reply JAMA - Journal of the American Medical Association, 304 (9), pp. 964-965. | Read more

Randall LM, Kenangalem E, Lampah DA, Tjitra E, Mwaikambo ED, Handojo T, Piera KA, Zhao ZZ, de Labastida Rivera F, Zhou Y et al. 2010. A study of the TNF/LTA/LTB locus and susceptibility to severe malaria in highland papuan children and adults. Malar J, 9 (1), pp. 302. | Citations: 10 (Scopus) | Show Abstract | Read more

BACKGROUND: Severe malaria (SM) syndromes caused by Plasmodium falciparum infection result in major morbidity and mortality each year. However, only a fraction of P. falciparum infections develop into SM, implicating host genetic factors as important determinants of disease outcome. Previous studies indicate that tumour necrosis factor (TNF) and lymphotoxin alpha (LTα) may be important for the development of cerebral malaria (CM) and other SM syndromes. METHODS: An extensive analysis was conducted of single nucleotide polymorphisms (SNPs) in the TNF, LTA and LTB genes in highland Papuan children and adults, a population historically unexposed to malaria that has migrated to a malaria endemic region. Generated P-values for SNPs spanning the LTA/TNF/LTB locus were corrected for multiple testing of all the SNPs and haplotype blocks within the region tested through 10,000 permutations. A global P-value of < 0.05 was considered statistically significant. RESULTS: No associations between SNPs in the TNF/LTA/LTB locus and susceptibility to SM in highland Papuan children and adults were found. CONCLUSIONS: These results support the notion that unique selective pressure on the TNF/LTA/LTB locus in different populations has influenced the contribution of the gene products from this region to SM susceptibility.

Le VT, Phan TQ, Do QH, Nguyen BH, Lam QB, Bach VC, Truong HK, Tran TH, Nguyen VVC, Tran TT et al. 2010. Viral etiology of encephalitis in children in southern Vietnam: results of a one-year prospective descriptive study. PLoS neglected tropical diseases, 4 (10), | Citations: 50 (Scopus) | Show Abstract

Acute encephalitis is an important and severe disease in children in Vietnam. However, little is known about the etiology while such knowledge is essential for optimal prevention and treatment. To identify viral causes of encephalitis, in 2004 we conducted a one-year descriptive study at Children's Hospital Number One, a referral hospital for children in southern Vietnam including Ho Chi Minh City. Children less than 16 years of age presenting with acute encephalitis of presumed viral etiology were enrolled. Diagnostic efforts included viral culture, serology and real time (RT)-PCRs. A confirmed or probable viral causative agent was established in 41% of 194 enrolled patients. The most commonly diagnosed causative agent was Japanese encephalitis virus (n = 50, 26%), followed by enteroviruses (n = 18, 9.3%), dengue virus (n = 9, 4.6%), herpes simplex virus (n = 1), cytomegalovirus (n = 1) and influenza A virus (n = 1). Fifty-seven (29%) children died acutely. Fatal outcome was independently associated with patient age and Glasgow Coma Scale (GCS) on admission. Acute encephalitis in children in southern Vietnam is associated with high mortality. Although the etiology remains unknown in a majority of the patients, the result from the present study may be useful for future design of treatment and prevention strategies of the disease. The recognition of GCS and age as predictive factors may be helpful for clinicians in managing the patient.

Kypraios T, O'Neill PD, Huang SS, Rifas-Shiman SL, Cooper BS. 2010. Assessing the role of undetected colonization and isolation precautions in reducing methicillin-resistant Staphylococcus aureus transmission in intensive care units. BMC Infect Dis, 10 (1), pp. 29. | Citations: 40 (Scopus) | Show Abstract | Read more

BACKGROUND: Screening and isolation are central components of hospital methicillin-resistant Staphylococcus aureus (MRSA) control policies. Their prevention of patient-to-patient spread depends on minimizing undetected and unisolated MRSA-positive patient days. Estimating these MRSA-positive patient days and the reduction in transmission due to isolation presents a major methodological challenge, but is essential for assessing both the value of existing control policies and the potential benefit of new rapid MRSA detection technologies. Recent methodological developments have made it possible to estimate these quantities using routine surveillance data. METHODS: Colonization data from admission and weekly nares cultures were collected from eight single-bed adult intensive care units (ICUs) over 17 months. Detected MRSA-positive patients were isolated using single rooms and barrier precautions. Data were analyzed using stochastic transmission models and model fitting was performed within a Bayesian framework using a Markov chain Monte Carlo algorithm, imputing unobserved MRSA carriage events. RESULTS: Models estimated the mean percent of colonized-patient-days attributed to undetected carriers as 14.1% (95% CI (11.7, 16.5)) averaged across ICUs. The percent of colonized-patient-days attributed to patients awaiting results averaged 7.8% (6.2, 9.2). Overall, the ratio of estimated transmission rates from unisolated MRSA-positive patients and those under barrier precautions was 1.34 (0.45, 3.97), but varied widely across ICUs. CONCLUSIONS: Screening consistently detected >80% of colonized-patient-days. Estimates of the effectiveness of barrier precautions showed considerable uncertainty, but in all units except burns/general surgery and one cardiac surgery ICU, the best estimates were consistent with reductions in transmission associated with barrier precautions.

Lubell Y, Mills AJ, Whitty CJM, Staedke SG. 2010. An economic evaluation of home management of malaria in Uganda: an interactive Markov model. PLoS One, 5 (8), pp. e12439. | Citations: 7 (Web of Science Lite) | Show Abstract | Read more

BACKGROUND: Home management of malaria (HMM), promoting presumptive treatment of febrile children in the community, is advocated to improve prompt appropriate treatment of malaria in Africa. The cost-effectiveness of HMM is likely to vary widely in different settings and with the antimalarial drugs used. However, no data on the cost-effectiveness of HMM programmes are available. METHODS/PRINCIPAL FINDINGS: A Markov model was constructed to estimate the cost-effectiveness of HMM as compared to conventional care for febrile illnesses in children without HMM. The model was populated with data from Uganda, but is designed to be interactive, allowing the user to adjust certain parameters, including the antimalarials distributed. The model calculates the cost per disability adjusted life year averted and presents the incremental cost-effectiveness ratio compared to a threshold value. Model output is stratified by level of malaria transmission and the probability that a child would receive appropriate care from a health facility, to indicate the circumstances in which HMM is likely to be cost-effective. The model output suggests that the cost-effectiveness of HMM varies with malaria transmission, the probability of appropriate care, and the drug distributed. Where transmission is high and the probability of appropriate care is limited, HMM is likely to be cost-effective from a provider perspective. Even with the most effective antimalarials, HMM remains an attractive intervention only in areas of high malaria transmission and in medium transmission areas with a lower probability of appropriate care. HMM is generally not cost-effective in low transmission areas, regardless of which antimalarial is distributed. Considering the analysis from the societal perspective decreases the attractiveness of HMM. CONCLUSION: Syndromic HMM for children with fever may be a useful strategy for higher transmission settings with limited health care and diagnosis, but is not appropriate for all settings. HMM may need to be tailored to specific settings, accounting for local malaria transmission intensity and availability of health services.

Leelahavarong P, Chaikledkaew U, Hongeng S, Kasemsup V, Lubell Y, Teerawattananon Y. 2010. A cost-utility and budget impact analysis of allogeneic hematopoietic stem cell transplantation for severe thalassemic patients in Thailand. BMC Health Serv Res, 10 (1), pp. 209. | Citations: 16 (Scopus) | Show Abstract | Read more

BACKGROUND: Hematopoietic stem cell transplantation (HSCT) is the only curative treatment available to severe thalassemic patients. The treatment, however, is very costly, particularly in the context of low and middle income countries, and no studies have been carried out to explore its economic justifiability. This study aimed to estimate the cost-utility of HSCT compared with blood transfusions combined with iron chelating therapy (BT-ICT) for severe thalassemia in Thailand, and to investigate the affordability of HSCT using a budget impact analysis. METHODS: A Markov model was used to estimate the relevant costs and health outcomes over the patients' lifetimes taking a societal perspective as recommended by Thailand's health technology assessment guidelines. All future costs and outcomes were discounted at a rate of 3% per annum. Primary outcomes of interest were lifetime costs, quality adjusted life years (QALYs) gained, and the incremental cost-effectiveness ratio (ICER) in Thai baht (THB) per QALY gained. RESULTS: Compared to BT-ICT, the incremental cost-effectiveness ratio increased with patient age from 80,700 to 183,000 THB per QALY gained for related HSCT and 209,000 to 953,000 THB per QALY gained for unrelated HSCT among patients aged 1 to 15 years (US$1= 34 THB). The governmental budget impact analysis showed that providing 200 related HSCT to patients aged 1 to 10 years, in accordance with the current infrastructure limitations, would initially require approximately 90 million additional THB per year. CONCLUSIONS: At a societal willingness to pay of 100,000 THB per QALY gained, related HSCT was likely to be a cost-effective and affordable treatment for young children with severe thalassemia in Thailand.

White LJ, Schukken YH, Dogan B, Green L, Döpfer D, Chappell MJ, Medley GF. 2010. Modelling the dynamics of intramammary E. coli infections in dairy cows: understanding mechanisms that distinguish transient from persistent infections. Veterinary research, 41 (2), pp. 13. | Citations: 1 (Scopus) | Show Abstract

The majority of intramammary infections with Escherichia coli in dairy cows result in transient infections with duration of about 10 days or less, although more persistent infections (2 months or longer) have been identified. We apply a mathematical model to explore the role of an intracellular mammary epithelial cell reservoir in the dynamics of infection. We included biological knowledge of the bovine immune response and known characteristics of the bacterial population in both transient and persistent infections. The results indicate that varying the survival duration of the intracellular reservoir reproduces the data for both transient and persistent infections. Survival in an intracellular reservoir is the most likely mechanism that ensures persistence of E. coli infections in mammary glands. Knowledge of the pathogenesis of persistent infections is essential to develop preventive and treatment programmes for these important infections in dairy cows. INRA, EDP Sciences, 2009

Olotu A, Fegan G, Williams TN, Sasi P, Ogada E, Bauni E, Wambua J, Marsh K, Borrmann S, Bejon P. 2010. Defining clinical malaria: the specificity and incidence of endpoints from active and passive surveillance of children in rural Kenya. PloS one, 5 (12), | Show Abstract

Febrile malaria is the most common clinical manifestation of P. falciparum infection, and is often the primary endpoint in clinical trials and epidemiological studies. Subjective and objective fevers are both used to define the endpoint, but have not been carefully compared, and the relative incidence of clinical malaria by active and passive case detection is unknown. We analyzed data from cohorts under active and passive surveillance, including 19,462 presentations with fever and 5,551 blood tests for asymptomatic parasitaemia. A logistic regression model was used to calculate Malaria Attributable Fractions (MAFs) for various case definitions. Incidences of febrile malaria by active and passive surveillance were compared in a subset of children matched for age and location. Active surveillance identified three times the incidence of clinical malaria as passive surveillance in a subset of children matched for age and location. Objective fever (temperature≥37.5°C) gave consistently higher MAFs than case definitions based on subjective fever. The endpoints from active and passive surveillance have high specificity, but the incidence of endpoints is lower on passive surveillance. Subjective fever had low specificity and should not be used in primary endpoint. Passive surveillance will reduce the power of clinical trials but may cost-effectively deliver acceptable sensitivity in studies of large populations.

Checkley AM, Chiodini PL, Dockrell DH, Bates I, Thwaites GE, Booth HL, Brown M, Wright SG, Grant AD, Mabey DC et al. 2010. Eosinophilia in returning travellers and migrants from the tropics: UK recommendations for investigation and initial management. J Infect, 60 (1), pp. 1-20. | Citations: 61 (Scopus) | Show Abstract | Read more

Eosinophilia is a common finding in returning travellers and migrants, and in this group it often indicates an underlying helminth infection. Infections are frequently either asymptomatic or associated with non-specific symptoms, but some can cause severe disease. Here the British Infection Society guidelines group reviews common and serious infectious causes of eosinophilia, and outlines a scheme for investigating returning travellers and migrants. All returning travellers and migrants with eosinophilia should be investigated with concentrated stool microscopy and strongyloides serology, in addition to tests specific to the region they have visited. Terminal urine microscopy and serology for schistosomiasis should also be performed in those returning from Africa. Eosinophilia is also a feature of significant non-infective conditions, which should be considered.

Nguyen NTK, Ha V, Tran NVT, Stabler R, Pham DT, Le TMV, van Doorn HR, Cerdeño-Tárraga A, Thomson N, Campbell J et al. 2010. The sudden dominance of blaCTX-M harbouring plasmids in Shigella spp. Circulating in Southern Vietnam. PLoS neglected tropical diseases, 4 (6), | Citations: 27 (Scopus) | Show Abstract | Read more

BACKGROUND: Plasmid mediated antimicrobial resistance in the Enterobacteriaceae is a global problem. The rise of CTX-M class extended spectrum beta lactamases (ESBLs) has been well documented in industrialized countries. Vietnam is representative of a typical transitional middle income country where the spectrum of infectious diseases combined with the spread of drug resistance is shifting and bringing new healthcare challenges. METHODOLOGY: We collected hospital admission data from the pediatric population attending the hospital for tropical diseases in Ho Chi Minh City with Shigella infections. Organisms were cultured from all enrolled patients and subjected to antimicrobial susceptibility testing. Those that were ESBL positive were subjected to further investigation. These investigations included PCR amplification for common ESBL genes, plasmid investigation, conjugation, microarray hybridization and DNA sequencing of a bla(CTX-M) encoding plasmid. PRINCIPAL FINDINGS: We show that two different bla(CTX-M) genes are circulating in this bacterial population in this location. Sequence of one of the ESBL plasmids shows that rather than the gene being integrated into a preexisting MDR plasmid, the bla(CTX-M) gene is located on relatively simple conjugative plasmid. The sequenced plasmid (pEG356) carried the bla(CTX-M-24) gene on an ISEcp1 element and demonstrated considerable sequence homology with other IncFI plasmids. SIGNIFICANCE: The rapid dissemination, spread of antimicrobial resistance and changing population of Shigella spp. concurrent with economic growth are pertinent to many other countries undergoing similar development. Third generation cephalosporins are commonly used empiric antibiotics in Ho Chi Minh City. We recommend that these agents should not be considered for therapy of dysentery in this setting.

Molyneux S, Kamuya D, Marsh V. 2010. Community members employed on research projects face crucial, often under-recognized, ethical dilemmas American Journal of Bioethics, 10 (3), pp. 24-26. | Citations: 16 (Scopus) | Read more

Sengaa J, Ndiritua M, Osundwaa J, Irimua G, English M. 2010. Computer aided learning to link evidence to paediatric learning and practice: a pilot in a medical school in a low income setting. Int Health, 2 (3), pp. 212-215. | Show Abstract | Read more

Bridging the gap between research evidence and practice is problematic in low income settings. Wereport medical students' experience with a pilot computer aided learning (CAL) program developed to enable students to explore research evidence supporting national guidelines. We asked 50 students to enter data from pre-set clinical scenarios, diagnose the severity of pneumonia/asthma and suggest treatment and then compare their diagnosis and treatment with that suggested by a computer algorithm based on the guidelines. Links to evidence supporting the guideline-suggested diagnosis and treatment were provided. Brief evidence summaries and video clips were accessed by 92% of students and full text articles by 86%. The majority of the students showed an interest in the CAL approach and suggested the scope of the approach be expanded to other illnesses. Such a system might provide one means to help students understand the link between research and policy and ultimately influence practice.

Mullei K, Mudhune S, Wafula J, Masamo E, English M, Goodman C, Lagarde M, Blaauw D. 2010. Attracting and retaining health workers in rural areas: Investigating nurses views on rural posts and policy interventions BMC Health Services Research, 10 (SUPPL. 1), | Citations: 27 (Scopus) | Show Abstract | Read more

Background. Kenya has bold plans for scaling up priority interventions nationwide, but faces major human resource challenges, with a lack of skilled workers especially in the most disadvantaged rural areas. Methods. We investigated reasons for poor recruitment and retention in rural areas and potential policy interventions through quantitative and qualitative data collection with nursing trainees. We interviewed 345 trainees from four purposively selected Medical Training Colleges (MTCs) (166 pre-service and 179 upgrading trainees with prior work experience). Each interviewee completed a self-administered questionnaire including likert scale responses to statements about rural areas and interventions, and focus group discussions (FGDs) were conducted at each MTC. Results. Likert scale responses indicated mixed perceptions of both living and working in rural areas, with a range of positive, negative and indifferent views expressed on average across different statements. The analysis showed that attitudes to working in rural areas were significantly positively affected by being older, but negatively affected by being an upgrading student. Attitudes to living in rural areas were significantly positively affected by being a student at the MTC furthest from Nairobi. During FGDs trainees raised both positive and negative aspects of rural life. Positive aspects included lower costs of living and more autonomy at work. Negative issues included poor infrastructure, inadequate education facilities and opportunities, higher workloads, and inadequate supplies and supervision. Particular concern was expressed about working in communities dominated by other tribes, reflecting Kenyas recent election-related violence. Quantitative and qualitative data indicated that students believed several strategies could improve rural recruitment and retention, with particular emphasis on substantial rural allowances and the ability to choose their rural location. Other interventions highlighted included provision of decent housing, and more rapid career advancement. However, recently introduced short term contracts in named locations were not favoured due to their lack of pension plans and job security. Conclusions. This study identified a range of potential interventions to increase rural recruitment and retention, with those most favored by nursing students being additional rural allowances, and allowing choice of rural location. Greater investment is needed in information systems to evaluate the impact of such policies. © 2010 Wafula et al; licensee BioMed Central Ltd.

Warren J, Goodyear-Smith F, Miller D, Warren D, Paton C, Mabotuwana T, Arroll B. 2010. An integrated electronic lifestyle and mental health patient self-assessment for general practice: Design and initial field study Health Care and Informatics Review Online, 14 (4), pp. 18-25. | Citations: 4 (Scopus) | Show Abstract

The Case-finding and Help Assessment Tool (CHAT) is a validated self-administered lifestyle and mood assessment assessing problem drinking, smoking, other drug use, gambling, anxiety, depression, abuse, anger and physical inactivity. Herein we present development and initial acceptability assessment of an electronic version (eCHAT) for use by patients at the general practice immediately prior to consultation with their general practitioner (GP). The system is designed to allow patients to undertake the eCHAT interview using a touchscreen display and to then provide the assessment data to the GP through their Practice Management System (PMS) for follow-up discussion with the patient. After initial feedback and subsequent minor modifications in a laboratory setting, the tool was deployed consecutively to two general practices. Fifty-one consenting adult patients completed a feedback survey. In addition to the patient feedback, a focus group of GP users, developers and researchers identified further issues for refinement of the system. Initial issues included the challenge of achieving a simple and reliable user interface design for patients to identify themselves. Subsequent to modification for this, eCHAT is found to be usable and acceptable for patients in the GP setting. In response to the focus group feedback, the PMS display for use by the GP in consultation has been modified to provide summary as well as detailed information about the eCHAT results. Further research directions include a randomised controlled trial to assess the impact of eCHAT screening on overall quality-of-life, and development of Web and mobile interfaces.

Graves N, Harbarth S, Beyersmann J, Barnett A, Halton K, Cooper B. 2010. Estimating the cost of health care-associated infections: mind your p's and q's. Clin Infect Dis, 50 (7), pp. 1017-1021. | Citations: 76 (Scopus) | Show Abstract | Read more

Monetary valuations of the economic cost of health care-associated infections (HAIs) are important for decision making and should be estimated accurately. Erroneously high estimates of costs, designed to jolt decision makers into action, may do more harm than good in the struggle to attract funding for infection control. Expectations among policy makers might be raised, and then they are disappointed when the reduction in the number of HAIs does not yield the anticipated cost saving. For this article, we critically review the field and discuss 3 questions. Why measure the cost of an HAI? What outcome should be used to measure the cost of an HAI? What is the best method for making this measurement? The aim is to encourage researchers to collect and then disseminate information that accurately guides decisions about the economic value of expanding or changing current infection control activities.

Arnold ME, Carrique-Mas JJ, Davies RH. 2010. Sensitivity of environmental sampling methods for detecting Salmonella Enteritidis in commercial laying flocks relative to the within-flock prevalence. Epidemiol Infect, 138 (3), pp. 330-339. | Citations: 29 (Scopus) | Show Abstract | Read more

The objective of this study was to estimate the sensitivity of three different sampling/testing methodologies for the detection of Salmonella Enteritidis in commercial egg-laying flocks relative to the within-flock prevalence. The following methods were compared on 21 farms: (1) The European Union (EU) baseline survey method (five faecal and two dust samples); (2) an in-house method that involved collecting 10 dust and 10 faecal samples into jars with buffered peptone water, and (3) a method involving single samples of pooled faeces and dust that has been adopted as a monitoring method for the National Control Programme across the EU (the NCP method). Testing of individual bird ovaries/oviduct and caeca was carried out on each flock, and the sensitivity of each sampling method was estimated relative to the within-flock prevalence using Bayesian methods. Results showed that the sensitivity of all the sampling methods increased as the within-flock prevalence increased, and that all were more efficient than individual bird sampling for detection of S. Enteritidis in commercial flocks. The in-house method was the most sensitive of the methods compared, with a 98% power to detect a 0.1% prevalence, and the NCP method the least sensitive, with a 93% power to detect a prevalence of 20%.

Arnold ME, Papadopoulou C, Davies RH, Carrique-Mas JJ, Evans SJ, Hoinville LJ. 2010. Estimation of Salmonella prevalence in UK egg-laying holdings. Prev Vet Med, 94 (3-4), pp. 306-309. | Citations: 10 (Scopus) | Show Abstract | Read more

As part of an EU-wide programme to reduce the prevalence of Salmonella in commercial egg-laying holdings, the EU has set for the UK an annual target of 10% reduction in the prevalence of Salmonella Enteritidis and Salmonella Typhimurium in commercial egg-laying holdings. To assist in demonstrating such a reduction, it is very important to obtain an accurate as possible baseline prevalence for Salmonella. The objective of this study was to provide a baseline estimate of the Salmonella prevalence in egg-laying holdings in the UK. Data from an EU baseline survey for Salmonella in UK commercial egg-laying flocks were therefore analysed using Bayesian methods, taking into account the sampling of only 1 flock per holding and estimates of the test sensitivity of the methods used in the EU baseline survey. In addition, in the UK the majority of the eggs come from farms which have participated in voluntary monitoring programmes for Salmonella since the early 1990s, and this data was also used, along with a prior estimate of the test sensitivity of voluntary surveillance. Results indicated that a true prevalence 14% for Salmonella Enteriditis and Typhimurium, and 18% for all serovars, both of these estimates being higher than has previously been reported from the EU baseline survey data. It is also shown that the sensitivity of voluntary surveillance is low, and it will therefore be important to compare results from "official" and "non-official" samples to check that the sampling performed in the National Control Plan is as sensitive as expected.

Snow LC, Davies RH, Christiansen KH, Carrique-Mas JJ, Cook AJC, Evans SJ. 2010. Investigation of risk factors for Salmonella on commercial egg-laying farms in Great Britain, 2004-2005. Vet Rec, 166 (19), pp. 579-586. | Citations: 41 (Scopus) | Show Abstract | Read more

In 2004/05, all European Union member states were required to carry out standardised prevalence surveys to establish the baseline prevalence of Salmonella in commercial laying flocks. As part of the survey in Great Britain, additional data were collected from 380 of the enrolled laying hen holdings to investigate risk factors for Salmonella at farm level. Stratified, simple random sampling was used to select holdings from which dust and boot swab samples were collected and tested for Salmonella using a modification of ISO 6579:2002. Using a multivariable logistic model weighted to account for the survey design, several factors significantly associated with Salmonella and Salmonella Enteritidis status were identified. Larger holdings (>or=30,000 birds) were found to be at higher risk of Salmonella (odds ratio [OR] 4.79, P=0.025), while vaccination (OR 0.28, P=0.013), providing foot dips with brushes (OR 0.27, P=0.042), washing and disinfecting the house at depopulation (OR 0.19, P=0.003), having a clean car park away from house (OR 0.14, P=0.001), using an independent (OR 0.19, P=0.007) or other non-company (OR 0.40, P=0.049) source of feed, being over 1 km from the nearest neighbouring farm (OR 0.45, P=0.021) and the presence of cats and dogs on the farm (OR 0.26, P=0.002) or on contiguous farms (OR 0.44, P=0.030) reduced the risk of any Salmonella serovars being present. Factors found to be associated specifically with an increased risk of S Enteritidis infection included holding size (OR 14.88, P=0.001) and frequent sightings of rats (OR 8.17, P<0.001) or mice (OR 5.78, P=0.006). Non-caged systems (OR 0.14, P=0.002), vaccination (OR 0.08, P=0.001), the use of a non-company feed source (OR 0.11, P=0.003), running the site as all-in/all-out (OR 0.06, P<0.001) and the presence of cats and dogs on the farm (OR 0.14, P=0.002) were associated with a reduced risk.

Mueller-Doblies D, Carrique-Mas JJ, Sayers AR, Davies RH. 2010. A comparison of the efficacy of different disinfection methods in eliminating Salmonella contamination from turkey houses. J Appl Microbiol, 109 (2), pp. 471-479. | Citations: 17 (Scopus) | Show Abstract | Read more

AIMS: This study aimed to compare the efficacy of different disinfection methods in eliminating Salmonella contamination from turkey houses. METHODS AND RESULTS: Fifty depopulated turkey houses which had all housed Salmonella-positive flocks were visited after cleaning and disinfection. A minimum of 45 swab samples from different surfaces were taken per house and analysed for the presence of Salmonella. The sampled surfaces included intact floor surfaces, floor cracks, walls, feeders, drinkers, anteroom, nestboxes and miscellaneous items. Houses were grouped according to the disinfectant which had been used and the efficacy of the different groups of disinfectants was compared. Sixty-eight % of houses tested positive for Salmonella after C&D. Out of 4440 samples, 207 tested positive for Salmonella, giving an overall sample prevalence of 4.7%. There was no significant difference in the level of residual contamination between breeding, rearing and finishing houses. Products containing a mixture of formaldehyde, glutaraldehyde and quaternary ammonium compounds (QAC) performed significantly better than products containing hydrogen peroxide and peracetic acid. Cleaning and disinfection was least effective in nestboxes and anterooms. CONCLUSIONS: Thorough cleaning and the choice of a suitable disinfectant are crucial if Salmonella contamination of turkey houses is to be eliminated. SIGNIFICANCE AND IMPACT OF THE STUDY: This study shows that disinfectants containing a mixture of formaldehyde, glutaraldehyde and QAC perform significantly better under field conditions than oxidising products and should therefore be the first choice for disinfection of turkey premises where Salmonella is present.

Wales AD, Carrique-Mas JJ, Rankin M, Bell B, Thind BB, Davies RH. 2010. Review of the carriage of zoonotic bacteria by arthropods, with special reference to Salmonella in mites, flies and litter beetles. Zoonoses Public Health, 57 (5), pp. 299-314. | Citations: 30 (Scopus) | Show Abstract | Read more

This systematic review considers the relationship between arthropods commonly found in and around livestock premises and zoonotic bacteria. The principal focus is upon insects and arachnids on poultry units, where houses, litter and manure provide good conditions for the growth, multiplication and protection of flies, beetles and mites, and where zoonotic pathogens such as Salmonella and Campylobacter are prevalent. Other members of the Enterobacteriaceae and the taxa Clostridium, Helicobacter, Erysipelas and Chlamydiaceae are also discussed. Salmonella is widely distributed in the flies of affected livestock units and is detectable to a lesser degree in beetles and mites. Persistent carriage appears to be common and there is some field and experimental evidence to support arthropod-mediated transmission between poultry flocks, particularly carry-over from one flock to the next. Campylobacter may readily be isolated from arthropods in contact with affected poultry flocks, although carriage is short-lived. There appears to be a role for flies, at least, in the breaching of biosecurity around Campylobacter-negative flocks. The carriage of other zoonotic bacteria by arthropods has been documented, but the duration and significance of such associations remain uncertain in the context of livestock production.

Buchy P, Vong S, Chu S, Garcia JM, Hien TT, Hien VM, Channa M, Ha Q, Chau NV, Simmons C et al. 2010. Kinetics of neutralizing antibodies in patients naturally infected by H5N1 virus. PloS one, 5 (5), | Citations: 7 (Scopus)

Atterbury RJ, Davies RH, Carrique-Mas JJ, Morris V, Harrison D, Tucker V, Allen VM. 2010. Effect of delivery method on the efficacy of Salmonella vaccination in chickens. Vet Rec, 167 (5), pp. 161-164. | Citations: 5 (Scopus) | Show Abstract | Read more

To investigate whether the efficacy of live vaccines is influenced by the mode of vaccine delivery, a widely-used UK live commercial Salmonella Enteritidis vaccine was delivered to pullet chicks either by spray, in drinking water, or in combination with a bivalent vaccine containing inactivated Salmonella Enteritidis and Salmonella Typhimurium. The birds were subsequently challenged with 10(2) or 10(8) colony-forming units (cfu) of Salmonella Enteritidis through drinking water at either six or 20 weeks of age. Ten days after the challenge, the birds were euthanased and their caecal contents cultured for Salmonella. All of the vaccinated groups contained fewer Salmonella Enteritidis-positive birds than the unvaccinated groups. The 'spray-vaccinated' group contained significantly fewer Salmonella Enteritidis-positive birds than the 'water-vaccinated' group after challenge with 10(8) cfu at 20 weeks. However, there was little or no difference at the other challenge time points between the groups that received vaccine through different modes of delivery.

Featherstone CA, Reichel R, Snow LC, Davies RH, Christiansen KH, Carrique-Mas JJ, Evans SJ. 2010. Investigation of risk factors for Salmonella on fattening-turkey farms. Epidemiol Infect, 138 (10), pp. 1427-1438. | Citations: 9 (Scopus) | Show Abstract | Read more

A cross-sectional study into risk factors for Salmonella was undertaken using data gathered from 252 fattening turkey flocks in the UK. The data was derived from the EU baseline survey conducted during 2006 and 2007, in addition to a voluntary questionnaire. Multivariate logistic regression models identified significant risk factors for Salmonella spp. and Salmonella Typhimurium. A decreased risk of Salmonella spp. infection was associated with a history of intestinal illness in the sampled flock (OR 0.17), the use of wood shavings as litter (OR 0.21), use of disinfectant in the cleaning process (OR 0.25), incineration of dead birds on farm (OR 0.29), seasonal production (OR 0.31), farm staff also working with cattle (OR 0.31), and the presence of pigs on neighbouring farms (OR 0.38). The risk of isolating Salmonella spp. varied according to the company from which the poults were sourced. A reduced risk of S. Typhimurium infection was associated with the use of wax blocks to control rodents (OR 0.09), using mains water (OR 0.19) and having a Salmonella test programme (OR 0.23). An increased risk of S. Typhimurium infection was associated with storage of items around the turkey house (OR 5.20), evidence of mice (OR 4.71) and a soil surface surrounding the turkey house (OR 2.70). This study therefore identifies a number of important practical measures which can be implemented by farmers and veterinarians within the turkey industry to assist in the control of salmonellosis at the farm level.

Carrique-Mas JJ, Willmington JA, Papadopoulou C, Watson EN, Davies RH. 2010. Salmonella infection in cattle in Great Britain, 2003 to 2008. Vet Rec, 167 (15), pp. 560-565. | Citations: 21 (Scopus) | Show Abstract | Read more

Surveillance data for clinical disease in cattle in Great Britain due to Salmonella infections were analysed for the period 2003 to 2008 in order to describe seasonality and to investigate possible associations between Salmonella diagnoses and other variables such as region, climate, age and production type. A clear seasonal pattern was shown for Salmonella infection, coinciding with the second half of the year. The incidence of Salmonella Dublin and Salmonella Typhimurium was highest in the west of the country, which has the greatest cattle density, but this was not a feature of diagnoses with other serovars. Abortion was a more common clinical sign of S Dublin infections, but was relatively unusual in the case of S Typhimurium. The observed clinical picture and age of affected animals were largely determined by the seasonality of dairy cattle calving in Great Britain.

Abubakar SB, Abubakar IS, Habib AG, Nasidi A, Durfa N, Yusuf PO, Larnyang S, Garnvwa J, Sokomba E, Salako L et al. 2010. Pre-clinical and preliminary dose-finding and safety studies to identify candidate antivenoms for treatment of envenoming by saw-scaled or carpet vipers (Echis ocellatus) in northern Nigeria Toxicon, 55 (4), pp. 719-723. | Citations: 35 (Scopus) | Show Abstract | Read more

The aim of this study was to identify candidate antivenoms with specific activity against the venom of the saw-scaled or carpet viper (Echis ocellatus) in northern Nigeria, where bites by this species cause great morbidity and mortality but where effective antivenoms have become scarce and unaffordable. Selected antivenoms were destined to be compared by randomised controlled clinical trials (RCTs). Standard pre-clinical neutralisation assays were carried out in rodents. We included two licensed antivenoms of established clinical efficacy and 6 candidate antivenoms. Although 6 of the tested antivenoms showed promising efficacy, all but 3 were excluded from further study because of inadequate pre-clinical efficacy or because they were unavailable or unaffordable for the anticipated RCTs. Median effective doses (ED 50 ) of the remaining three candidate antivenoms suggested that the following doses might neutralise the maximum observed venom yield of 24.8mg (dry weight) of venom milked from captive E. ocellatus: 10ml of MicroPharm " EchiTAb G" (ET-G) antivenom; 30ml of Instituto Clodomiro Picado " EchiTAb-Plus-ICP" (ET-Plus) antivenom; 50ml of VacSera, Cairo " EgyVac" antivenom. A preliminary clinical dose-finding and safety study of these three antivenoms was carried out in 24 patients with incoagulable blood after E. ocellatus bites who were not severely envenomed. A 3+3 dose escalation design was employed. Initial doses of 10ml ET-G and 30ml ET-Plus restored blood coagulability in groups of 6 patients with early mild reactions (pruritus only) in not more than one third of them. EgyVac antivenom did not fulfil efficacy or safety criteria in 12 patients. On the basis of these results, ET-G and ET-Plus were selected for comparison in a RCT. © 2009 Elsevier Ltd.

Opiyo N, English M. 2010. In-service training for health professionals to improve care of the seriously ill newborn or child in low and middle-income countries (Review). Cochrane Database Syst Rev, 2015 (4), pp. CD007071. | Citations: 11 (Scopus) | Show Abstract | Read more

BACKGROUND: A variety of emergency care training courses based on developed country models are being promoted as a strategy to improve the quality of care of the seriously ill newborn or child in developing countries. Clear evidence of their effectiveness is lacking. OBJECTIVES: To investigate the effectiveness of in-service training of health professionals on their management and care of the seriously ill newborn or child in low and middle-income settings. SEARCH STRATEGY: We searched The Cochrane Register of Controlled Trials (CENTRAL), the Specialised Register of the Cochrane EPOC group (both up to May 2009), MEDLINE (1950 to May 2009), EMBASE (1980 to May 2009), CINAHL (1982 to March 2008), ERIC / LILACS / WHOLIS (all up to October 2008), and ISI Science Citation Index Expanded and ISI Social Sciences Citation Index (both from 1975 to March 2009). We checked references of retrieved articles and reviews and contacted authors to identify additional studies. SELECTION CRITERIA: Randomised controlled trials (RCTs), cluster-randomised trials (CRTs), controlled clinical trials (CCTs), controlled before-after studies (CBAs) and interrupted time series studies (ITSs) that reported objectively measured professional practice, patient outcomes, health resource /services utilization, or training costs in healthcare settings (not restricted to studies in low-income settings). DATA COLLECTION AND ANALYSIS: We independently selected studies for inclusion, abstracted data using a standardised form, and assessed study quality. Meta-analysis was not appropriate. Study results were summarised and appraised. MAIN RESULTS: Two studies of varied designs were included. In one RCT of moderate quality, Newborn Resuscitation Training (NRT) was associated with a significant improvement in performance of adequate initial resuscitation steps (risk ratio 2.45, 95% confidence interval (CI) 1.75 to 3.42, P < 0.001, adjusted for clustering) and a reduction in the frequency of inappropriate and potentially harmful practices (mean difference 0.40, 95% CI 0.13 to 0.66, P = 0.004). In the second RCT, available limited data suggested that there was improvement in assessment of breathing and newborn care practices in the delivery room following implementation of Essential Newborn Care (ENC) training. AUTHORS' CONCLUSIONS: There is limited evidence that in-service neonatal emergency care courses improve health-workers' practices when caring for a seriously ill newborn although there is some evidence of benefit. Rigorous trials evaluating the impact of refresher emergency care training on long-term professional practices are needed. To optimise appropriate policy decisions, studies should aim to collect data on resource use and costs of training implementation.

Thuong NTT, Dunstan S. 2010. Human genetic susceptibility to tuberculous meningitis in Vietnamese population Kekkaku, 85 (3), pp. 171-175. | Show Abstract

A case-control study of TLR2 candidate found that genotype 597CC was associated with susceptibility to tuberculous meningitis (TBM) (OR = 3.26) 1) . SNP C558T on TIRAP was found to be associated with increased susceptibility to TBM in this same Vietnamese cohort 2 ) (OR= 3.02). The co-inheritance of TLR2 SNP T597C and TIRAP SNP C558T increases susceptibility to TBM (OR = 5.4). The interaction between polymorphisms on TLR2 and TIRAP in TB patients and M. tuberculosis strains shows that individuals with the C allele of TLR2 T597C are more likely to have TBM caused by the Beijing genotype (OR=1.91) than other individuals. TBM patients with CC genotype of TLR2 T597C have higher risk of disease caused by the Beijing genotype (OR=4.48). This provides evidence that M.tuberculosis genotype influences clinical disease phenotype 3) . A genome-wide case-control association study of 250,000 SNPs indicated that there are SNP marker profiles which are specifically associated with the susceptibility to, or protection from, clinical phenotypes of TB (data not yet published). Microarrays were used to determine gene expression profiles of over 38,500 genes from ex-vivo M.tuberculosis stimulated macrophages isolated from latent (LTB), PTB and TBM. These results suggest that distinct macrophage responses are associated with different clinical forms of tuberculosis and that the innate immune response may regulate clinical outcomes 4) . Overall, the work presented in these studies contributes to the current knowledge of the genetic basis of TB, and more specifically of TBM, and provides novel insights into the molecular pathogenesis of TB.

Yeo TW, Lampah DA, Tjitra E, Gitawati R, Darcy CJ, Jones C, Kenangalem E, McNeil YR, Granger DL, Lopansri BK et al. 2010. Increased asymmetric dimethylarginine in severe falciparum malaria: Association with impaired nitric oxide bioavailability and fatal outcome PLoS Pathogens, 6 (4), pp. 1-8. | Citations: 49 (Scopus) | Show Abstract

Asymmetrical dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthase (NOS), is a predictor of mortality in critical illness. Severe malaria (SM) is associated with decreased NO bioavailability, but the contribution of ADMA to the pathogenesis of impaired NO bioavailability and adverse outcomes in malaria is unknown. In adults with and without falciparum malaria, we tested the hypotheses that plasma ADMA would be: 1) increased in proportion to disease severity, 2) associated with impaired vascular and pulmonary NO bioavailability and 3) independently associated with increased mortality. We assessed plasma dimethylarginines, exhaled NO concentrations and endothelial function in 49 patients with SM, 78 with moderately severe malaria (MSM) and 19 healthy controls (HC). Repeat ADMA and endothelial function measurements were performed in patients with SM. Multivariable regression was used to assess the effect of ADMA on mortality and NO bioavailability. Plasma ADMA was increased in SM patients (0.85 μM; 95% CI 0.74-0.96) compared to those with MSM (0.54 μM; 95%CI 0.5-0.56) and HCs (0.64 μM; 95%CI 0.58-0.70; p < 0.001). ADMA was an independent predictor of mortality in SM patients with each micromolar elevation increasing the odds of death 18 fold (95% CI 2.0-181; p = 0.01). ADMA was independently associated with decreased exhaled NO (r s =20.31) and endothelial function (r s =20.32) in all malaria patients, and with reduced exhaled NO (r s =-0.72) in those with SM. ADMA is increased in SM and associated with decreased vascular and pulmonary NO bioavailability. Inhibition of NOS by ADMA may contribute to increased mortality in severe malaria.

Thwaites GE, United Kingdom Clinical Infection Research Group (UKCIRG). 2010. The management of Staphylococcus aureus bacteremia in the United Kingdom and Vietnam: a multi-centre evaluation. PLoS One, 5 (12), pp. e14170. | Citations: 16 (Scopus) | Show Abstract | Read more

BACKGROUND: Staphylococcus aureus bacteremia is a common and serious infection worldwide and although treatment guidelines exist, there is little consensus on optimal management. In this study we assessed the variation in management and adherence to treatment guidelines of S. aureus bacteremia. METHODOLOGY/PRINCIPAL FINDINGS: We prospectively recorded baseline clinical characteristics, management, and in-hospital outcome of all adults with S. aureus bacteremia treated consecutively over one year in eight centres in the United Kingdom, three in Vietnam and one in Nepal. 630 adults were treated for S. aureus bacteremia: 549 in the UK (21% methicillin-resistant), 80 in Vietnam (19% methicillin-resistant) and 1 in Nepal. In the UK, 41% had a removable infection focus (50% intravenous catheter-related), compared to 12% in Vietnam. Significantly (p<0.001) higher proportions of UK than Vietnamese patients had an echocardiogram (50% versus 28%), received more than 14 days antibiotic therapy (84% versus 44%), and received >50% of treatment with oral antibiotics alone (25% versus 4%). UK centres varied significantly (p<0.01) in the proportions given oral treatment alone for >50% of treatment (range 12-40%), in those treated for longer than 28 days (range 13-54%), and in those given combination therapy (range 14-94%). 24% died during admission: older age, time in hospital before bacteremia, and an unidentified infection focus were independent predictors of in-hospital death (p<0.001). CONCLUSIONS/SIGNIFICANCE: The management of S. aureus bacteremia varies widely between the UK and Vietnam and between centres in the UK with little adherence to published guidelines. Controlled trials defining optimal therapy are urgently required.

Cox AP, Tosas O, Tilley A, Picozzi K, Coleman P, Hide G, Welburn SC. 2010. Constraints to estimating the prevalence of trypanosome infections in East African zebu cattle Parasites & Vectors, 3 (1), pp. 82-82. | Read more

Ranford-Cartwright LC, Sinha A, Humphreys GS, Mwangi JM. 2010. New synchronization method for Plasmodium falciparum Malaria Journal, 9 (1), pp. 170-170. | Read more

Blacksell SD, Jenjaroen K, Phetsouvanh R, Wuthiekanun V, Day NPJ, Newton PN, Ching W-M. 2010. Accuracy of AccessBio Immunoglobulin M and Total Antibody Rapid Immunochromatographic Assays for the Diagnosis of Acute Scrub Typhus Infection. Clin Vaccine Immunol, 17 (2), pp. 263-266. | Citations: 21 (Scopus) | Show Abstract | Read more

Using archived samples, we assessed the diagnostic capacity of a rapid immunochromatographic test (ICT) for the detection of Orientia tsutsugamushi IgM and total antibodies to aid with the diagnosis of acute scrub typhus infection in febrile patients in Laos. The sensitivity and the specificity of the ICT for the detection of IgM were 96.8% (121/125 samples; 95% confidence interval [CI], 92.1 to 99.1%) and 93.3% (98/105 samples; 95% CI, 86.7 to 97.3%), respectively. For the detection of total antibodies, the sensitivity was 97.6% (122/125 samples; 95% CI, 93.1 to 99.5%), but the specificity was much lower, at 71.4% (75/105 samples; 95% CI, 61.8 to 79.8%).

Gutiérrez JM, Williams D, Fan HW, Warrell DA. 2010. Snakebite envenoming from a global perspective: Towards an integrated approach. Toxicon, 56 (7), pp. 1223-1235. | Citations: 112 (Scopus) | Show Abstract | Read more

Snakebite envenoming is a neglected public health challenge of compelling importance in many regions of the world, particularly sub-Saharan Africa, Asia, Latin America and Papua-New Guinea. Addressing the problem of snakebite effectively demands an integrated multifocal approach, targeting complex problems and involving many participants. It must comprise: (a) Acquisition of reliable information on the incidence and mortality attributable to snakebite envenoming, and the number of people left with permanent sequelae. (b) Improvements in production of effective and safe antivenoms, through strategies aimed at strengthening the technological capacity of antivenom manufacturing laboratories. (c) Increasing the capacity of low-income countries to produce specific immunogens(snake venoms) locally, and to perform their own quality control of antivenoms. (d) Commitments from regional producers to manufacture antivenoms for countries where antivenom production is not currently feasible. (e) Implementation of financial initiatives guaranteeing the acquisition of adequate volumes of antivenom at affordable prices in low-income countries. (f) Performance of collaborative studies on the safety and effectiveness of antivenoms assessed preclinically and by properly designed clinical trials. (g) Development of antivenom distribution programmes tailored to the real needs and epidemiological situations of rural areas in each country. (h) Permanent training programmes for health staff, particularly in rural areas where snakebites are frequent.(i) Implementation of programmes to support those people whose snakebites resulted in chronic disabilities. (j) Preventive and educational programmes at the community level, with the active involvement of local organizations and employing modern methods of health promotion. Such an integrated approach, currently being fostered by the Global Snake Bite Initiative of the International Society on Toxinology and by the World Health Organization, will help to alleviate the enormous burden of human suffering inflicted by snakebite envenoming.

White NJ, Turner GDH, Medana IM, Dondorp AM, Day NPJ. 2010. The murine cerebral malaria phenomenon. Trends Parasitol, 26 (1), pp. 11-15. | Citations: 108 (Scopus) | Show Abstract | Read more

P.berghei ANKA infection in CBA or CB57BL/6 mice is used widely as a murine 'model' of human cerebral malaria (HCM), despite markedly different histopathological features. The pathology of the murine model is characterised by marked inflammation with little or no intracerebral sequestration of parasitised erythrocytes, whereas HCM is associated with intense intracerebral sequestration, often with little inflammatory response. There are now more than ten times as many studies each year of the murine model than on HCM. Of 48 adjunctive interventions evaluated in the murine model, 44 (92%) were successful, compared with only 1 (6%) of 17 evaluated in HCM during the same period. The value of the mouse model in identifying pathological processes or therapeutic interventions in human cerebral malaria is questionable.

Chapman SJ, Khor CC, Vannberg FO, Rautanen A, Segal S, Moore CE, Davies RJO, Day NP, Peshu N, Crook DW et al. 2010. NFKBIZ polymorphisms and susceptibility to pneumococcal disease in European and African populations. Genes Immun, 11 (4), pp. 319-325. | Citations: 20 (Scopus) | Show Abstract | Read more

The proinflammatory transcription factor nuclear factor-kappaB (NF-kappaB) has a central role in host defence against pneumococcal disease. Both rare mutations and common polymorphisms in the NFKBIA gene encoding the NF-kappaB inhibitor, IkappaB-alpha, associate with susceptibility to bacterial disease, but the possible role of polymorphisms within the related IkappaB-zeta gene NFKBIZ in the development of invasive pneumococcal disease (IPD) has not been reported previously. To investigate this further, we examined the frequencies of 22 single-nucleotide polymorphisms spanning NFKBIZ in two case-control studies, comprising UK Caucasian (n=1008) and Kenyan (n=723) individuals. Nine polymorphisms within a single UK linkage disequilibrium (LD) block and all four polymorphisms within the equivalent, shorter Kenyan LD block displayed either a significant association with IPD or a trend towards association. For each polymorphism, heterozygosity was associated with protection from IPD when compared with the combined homozygous states (for example, for rs600718, Mantel-Haenszel 2 x 2 chi(2)=7.576, P=0.006, odds ratio (OR)=0.67, 95% confidence interval (95% CI) for OR: 0.51-0.88; for rs616597, Mantel-Haenszel 2 x 2 chi(2)=8.715, P=0.003, OR=0.65, 95% CI: 0.49-0.86). We conclude that multiple NFKBIZ polymorphisms associate with susceptibility to IPD in humans. The study of multiple populations may aid in fine mapping of associations within extensive regions of strong LD ('transethnic mapping').

McGready R, Blacksell SD, Luksameetanasan R, Wuthiekanun V, Jedsadapanpong W, Day NPJ, Nosten F. 2010. First report of an Orientia tsutsugamushi type TA716-related scrub typhus infection in Thailand. Vector Borne Zoonotic Dis, 10 (2), pp. 191-193. | Citations: 6 (Scopus) | Show Abstract | Read more

Orientia tsutsugamushi causes scrub typhus and is a rural zoonosis endemic in the Asia Pacific region. This is the first report of O. tsutsugamushi TA716-like strain in a human in Thailand. The patient was in the 1st trimester of pregnancy when she developed scrub typhus. The O. tsutsugamushi strain TA716 was detected from her admission blood sample, and the pregnancy ended in spontaneous abortion. The effects of scrub typhus in pregnant women and the pregnancy outcome are sparsely documented in the published medical literature. Improved clinical recognition and laboratory diagnosis will be essential to better define the morbidity caused by this zoonosis especially in pregnancy.

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