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Kenya has joined the global efforts in search of an effective vaccine for COVID-19 with the start of a trial evaluating the ChAdOx1 nCoV-2019 Oxford coronavirus vaccine. Following the necessary approvals from regulators, as well as the national ministry of health, and Kilifi county, the first volunteers for the trial have recently received their vaccinations.
Placental and Cord Blood DNA Methylation Changes Associated With Gestational Diabetes Mellitus in a Marginalized Population: The Untold Role of Saturated Fats.
The role of DNA methylation (DNAm) and its modulation by dietary factors in gestational diabetes mellitus (GDM) remains underexplored, particularly in marginalized populations. This study investigates DNAm alterations in GDM-exposed cord blood and placenta and their association with maternal dietary quality and single nutrient intake in a low-income population from the Myanmar-Thailand border. A matched case-control design (GDM: n = 38, controls: n = 34) was selected from a Myanmar-Thailand pregnancy cohort. Dietary intake was assessed via 24-h recalls and analyzed using Nutritionist Pro, with dietary quality evaluated by the healthy eating index (HEI). DNAm was profiled in 72 cord blood and 72 placental samples using the Infinium MethylationEPIC array. Significant differences in dietary vitamin D, total folate, and saturated fat intake were observed between the groups. RnBeads analyses revealed hypomethylation as the predominant DNAm pattern in GDM, particularly at ADORA2B (placenta) and ZFP57 (cord blood) promoters. The excessive intake of saturated fats was associated with GDM hypomethylation profiles and negatively correlated with ZFP57 methylation levels. This study highlights the influence of saturated fat intake on epigenetic changes in pregnancy, revealing potential biomarkers for GDM and emphasizing the need for tailored, population-specific nutritional interventions to mitigate transgenerational health impacts.
Operational evaluation of the deployment of Malaria/CRP Duo and Dengue Duo rapid diagnostic tests for the management of febrile illness by village malaria workers in rural Cambodia
Abstract Introduction The decline in malaria cases in Cambodia has led to a relative increase in non-malarial febrile illness. In rural Cambodia, village malaria workers (VMWs) provide early diagnosis and treatment for malaria, but their role and relevance are diminishing as malaria cases decline. Expanding VMW roles would ensure continued utilisation of their services until malaria elimination is achieved and strengthen community health services. Methods A mixed methods operational research study was implemented to evaluate the use of two combination-RDTs (combo-RDTs) as an expansion of the VMW role, enabling VMWs in Cambodia to test for diseases other than malaria for the first time. VMWs in 78 villages in Battambang and Pailin Provinces were trained and provided with either a Malaria/CRP Duo or Dengue Duo RDT to assess febrile patients. Data were collected on VMW consultations, and combo-RDT usage and results. Focus group discussions (FGDs) and competency assessments of combo-RDT usage were conducted with VMWs. The main objectives were to determine whether VMWs could perform these combo-RDTs correctly and follow management algorithms, and whether deployment had an impact on VMW consultation rates. Perspectives concerning role expansion and the feasibility of conducting additional tests were also explored. Results Between June 2022, and May 2023, a total of 2,425 febrile patients were assessed with either a Malaria/CRP Duo or Dengue Duo RDT. Active dengue infection (NS1- and/or IgM-positive) was identified in 1.2% (11/915) of patients. Positive CRP results (> 20 mg/L) were found for 3.2% (48/1,510) of patients. Following deployment, there was an immediate mean increase of 4.4 VMW consultations per month, from 9.0 to 13.4 (p < 0.01). Competency assessments revealed that some VMWs had difficulty performing the Dengue Duo RDT, particularly in collecting the correct blood volume. This limitation may have led to false-negative dengue NS1 results. VMWs and community members were keen to broaden the skills and responsibilities of VMWs. Conclusions Deploying combo-RDTs to VMWs led to a higher utilization of their services. Difficulties performing some aspects of the Dengue Duo RDT, low positivity rates, and a lack of actionable outcomes within the existing context of VMW services suggest that alternative interventions may be better suited for VMW role expansion at this time. Overall, VMWs and community members were receptive to the expansion of the VMW role for a wider range of diseases other than malaria.
Identifying context-specific determinants to inform improvement of antimicrobial stewardship implementation in healthcare facilities in Asia: results from a scoping review and web-based survey among local experts.
International guidelines are available for the assessment and improvement of antimicrobial stewardship (AMS) programmes: an important strategy to address the escalating global antimicrobial resistance problem. However, existing AMS assessment tools lack contextual specificity for resource-limited settings, leading to limited applicability in Asia. This project aimed to identify relevant themes from current guidance documents to help develop a context-specific assessment tool that can be applied by healthcare facilities (HCFs) to improve local implementation.We performed a sequential approach of a scoping review to identify relevant assessment themes for Asia and an expert survey for getting feedback on the relevance of assessment stems developed from the scoping review. We reviewed English-language published documents discussing AMS implementation or assessment at HCFs globally and in Asia. Themes were derived through content analysis and classified following the predefined context dimensions to develop assessment stems, defined as containing one identified determinant that may influence implementation outcomes. The survey consisting of identified assessment stems was reviewed by 20 locally identified experts in Asia who rated the level of relevance of these stems in AMS implementation in the region.National leadership, training and technical support, and policy and guidance were the most commonly identified themes among 100 themes identified from 73 reviewed documents. From these themes, we developed 131 assessment stems for the expert survey. Of the 131 assessment stems, 117 (89%) were considered relevant for AMS implementation in Asia by at least 80% of respondents. These stems were included in the process of developing a global AMS assessment tool to support HCFs to improve their programmes.In conclusion, national leadership and support represent a distinct and important aspect affecting AMS implementation in HCFs in Asia. The identified assessment themes have substantial value for the formulation of locally relevant implementation strategies tailored to the Asian context.
Pharmacokinetic-pharmacodynamic modeling of benznidazole and its antitrypanosomal activity in a murine model of chronic Chagas disease.
BACKGROUND: There is an urgent need for improved treatments for Chagas disease, a neglected tropical infection caused by the protozoan parasite Trypanosoma cruzi. Benznidazole, the first line therapy, has severe limitations such as poor tolerability and variable efficacy in the chronic stage of infection. To optimize dosing regimens, a better understanding of the pharmacokinetic/pharmacodynamic (PK/PD) relationship for benznidazole is crucial. This study aimed to characterize the population pharmacokinetic properties of benznidazole in mice and investigate the relationship between exposure and antitrypanosomal activity in T. cruzi infected mice. METHODOLOGY/PRINCIPAL FINDINGS: Antitrypanosomal activity was assessed in 118 BALB/c mice with chronic-stage T. cruzi infection, utilizing highly sensitive in vivo bioluminescence imaging (BLI). Benznidazole was administered at doses ranging from 10 to 100 mg/kg for 5-20 days. The pharmacokinetic properties of benznidazole were evaluated in 52 uninfected BALB/c mice using nonlinear mixed-effects modeling. The relationship between simulated benznidazole exposure and sterile parasitological cure in the BLI experiments was evaluated by logistic regression and partial least squares - discriminant analysis. Benznidazole pharmacokinetics in mice were well described by a one-compartment disposition model with first-order absorption, with higher doses associated with slower absorption. Univariate logistic regression revealed a significant correlation between drug exposure and the probability of parasitological cure. Total plasma exposure, time above IC90 and peak plasma concentration were all strongly associated with efficacy, provided that benznidazole was administered for at least 5 days. CONCLUSIONS/SIGNIFICANCE: This is the first study to successfully quantify the dose-response relationship for benznidazole in T. cruzi-infected mice using preclinical BLI data. Our results underscore the complexity of distinguishing PK/PD drivers of efficacy due to high collinearity between PK/PD index parameters, and we propose dose-fractionation studies for future research. Studying the PK/PD relationship using the BLI model provides valuable insights, aiding hypothesis generation through endpoint assessment of parasite infection.
Implementation strategies to improve outcomes in patients with established cardiovascular disease in sub-Saharan Africa: A systematic review.
The protocol was registered in PROSPERO prior to the study implementation (ID: CRD42023465781). The protocol can be accessed at crd.york.ac.uk/PROSPERO/display_record.php?RecordID=465781.
Identification of undetected SARS-CoV-2 infections by clustering of Nucleocapsid antibody trajectories.
During the COVID-19 pandemic, numerous SARS-CoV-2 infections remained undetected. We combined results from routine monthly nose and throat swabs, and self-reported positive swab tests, from a UK household survey, linked to national swab testing programme data from England and Wales, together with Nucleocapsid (N-)antibody trajectories clustered using a longitudinal variation of K-means (N = 185,646) to estimate the number of infections undetected by either approach. Using N-antibody (hypothetical) infections and swab-positivity, we estimated that 7.4% (95%CI: 7.0-7.8%) of all true infections (detected and undetected) were undetected by both approaches, 25.8% (25.5-26.1%) by swab-positivity-only and 28.6% (28.4-28.9%) by trajectory-based N-antibody-classifications-only. Congruence with swab-positivity was respectively much poorer and slightly better with N-antibody classifications based on fixed thresholds or fourfold increases. Using multivariable logistic regression N-antibody seroconversion was more likely as age increased between 30-60 years, in non-white participants, those less (recently/frequently) vaccinated, for lower cycle threshold values in the range above 30, and in symptomatic and Delta (vs. BA.1) infections. Comparing swab-positivity data sources showed that routine monthly swabs were insufficient to detect infections and incorporating national testing programme/self-reported data substantially increased detection. Overall, whilst N-antibody serosurveillance can identify infections undetected by swab-positivity, optimal use requires fourfold-increase-based or trajectory-based analysis.
The Ebola Data Platform: A prospective, standardised, clinical dataset collected during the 2013-2016 West African Ebola outbreak.
The Ebola Data Platform (EDP) was developed to strengthen knowledge and capacity across health, research, and humanitarian communities to reduce the impact of Ebola through responsible data use. This collaborative initiative was established by West African governments, NGOs, academic organisations, and intra-governmental health organisations directly involved in the 2013-2016 West African Ebola outbreak. The platform was established to provide a centralised, standardised dataset of individual patient data collected during the outbreak for the purpose of research to improve Ebola treatment and control, and includes over 13,600 patient records of individuals infected and treated from 22 different Ebola treatment centres across Guinea, Sierra Leone, Liberia, and Nigeria. Patient data are available from treatment centre triage and admission, inpatient clinical observations, and outcomes, with outpatient follow-up available for some datasets. Data include signs and symptoms, pre-existing comorbidities, vital signs, laboratory testing, treatments, complications, dates of admission and discharge, mortality, viral strains, and other data. This publication describes characteristics of the EDP dataset, its architecture, methods for data access and tools for utilising the dataset.
Longer-term virologic outcomes on tenofovir-lamivudine-dolutegravir in second-line ART
Background: Dolutegravir in second-line antiretroviral therapy (ART) is more effective with recycled tenofovir than switching to zidovudine. However, dolutegravir resistance is more frequent in second-line compared to first-line ART.Objectives: We report long-term virologic outcomes from a clinical trial.Method: AntiRetroviral Therapy In Second-line: investigating Tenofovir-lamivudine-dolutegravir (ARTIST) was a randomised, double-blind, phase II clinical trial. Eligible participants had two consecutive HIV-1 RNA ≥ 1000 copies/mL on first-line ART, mostly tenofovir-emtricitabine-efavirenz. Participants were switched to tenofovir-lamivudine-dolutegravir (TLD) with lead-in 50 mg dolutegravir twice daily in stage one (n = 62), and randomised to TLD with additional lead-in 50 mg dolutegravir or placebo for the first 14 days in stage two (n = 130). We present results up to 158 weeks, combining stages one and two.Results: We enrolled 192 participants: 127/176 (72%) had resistance (Stanford score ≥ 15) to both tenofovir and lamivudine. At week 48, 151/186 (81%; 95% confidence interval [CI] 75%, 87%) had HIV-1 RNA 50 copies/mL. Of 127 participants with follow-up through week 158, 78% (95% CI 70%, 85%) maintained HIV-1 RNA 50 copies/mL, 11% had HIV-1 RNA 50–999 copies/mL, and 11% had HIV-1 RNA ≥ 1000 copies/mL. Twenty-nine participants met criteria for resistance testing: one developed intermediate-level dolutegravir resistance (G118R mutation) at week 96, and one had high-level dolutegravir resistance (E138K, G118R, G163R, T66A mutations) detected at week 146.Conclusion: Among adults switching to TLD with detectable HIV-1 RNA and substantial tenofovir and lamivudine resistance, a high proportion maintained virologic suppression up to 158 weeks. Emergent dolutegravir resistance occurred in ~1% of participants after 2–3 years on second-line TLD.
Disease outbreak data to inform decision-making: the role of disease spread models in the Lao P.D.R. African Swine Fever epidemic, 2019.
Understanding the spread of African Swine Fever (ASF) between villages in the southeast-Asian, low - middle income country context is critical if this high impact disease is to be controlled by good policy and effective field activities in these resource-poor settings. Using governmental reporting data from the 2019 outbreak of ASF in Lao People's Democratic Republic, spatial clustering techniques were used to identify clusters of outbreak villages. Then Approximate Bayesian Computation with Sequential Monte Carlo was used to estimate the transmission parameters of ASF virus between the villages within these clusters. We used a simple disease spread model to understand the impact of parameter estimation on predicted disease spread and thus decision-making. Six clusters of radius 16 to 153km were identified over the 7 month outbreak period. Within these clusters, the basic reproduction number (R0) ranged from 13 to 32 between-villages and whole-village infectious periods ranged from 62 to 68 days. The final model outputs were compared to the original field report data. We found that the ability of the estimated parameters to match field data was heavily reliant on how the original field surveillance data was reported. Specifically, in situations in which cases in a cluster appeared to have been reported as batches (lack of temporal specificity) our modelling approach failed to produce satisfactory outputs in terms of model fit and precision of estimates. This study demonstrates that surveillance for transboundary diseases not only has immediate benefit for disease response, but that good quality surveillance data is valuable for informing future planning for disease response via appropriately parameterised disease spread models. There is a need for ongoing quality control of surveillance and support for field veterinary services to ensure quality data that can be used to drive policy and decision-making.
Applying the Shuffle Model of Differential Privacy to Vector Aggregation
In this work we introduce a new protocol for vector aggregation in the context of the Shuffle Model, a recent model within Differential Privacy (DP). It sits between the Centralized Model, which prioritizes the level of accuracy over the secrecy of the data, and the Local Model, for which an improvement in trust is counteracted by a much higher noise requirement. The Shuffle Model was developed to provide a good balance between these two models through the addition of a shuffling step, which unbinds the users from their data whilst maintaining a moderate noise requirement. We provide a single message protocol for the summation of real vectors in the Shuffle Model, using advanced composition results. Our contribution provides a mechanism to enable private aggregation and analysis across more sophisticated structures such as matrices and higher-dimensional tensors, both of which are reliant on the functionality of the vector case.
Understanding the primary healthcare context in rural South and Southeast Asia: a village profiling study
Abstract Background Understanding contextual factors is critical to the success of health service planning and implementation. However, few contextual data are available at the village level in rural South and Southeast Asia. This study addressed the gap by profiling representative villages across seven sites in Thailand (n=3), Cambodia, Laos, Myanmar and Bangladesh. Methods Key informant surveys supplemented by other information sources were used to collect data from 687 villages on four key indicators (literacy rate, and percentages of attended deliveries, fully immunised children and latrine coverage), as well as access to various services. Data were analysed descriptively. Results Sites varied considerably. Five were highly diverse ethno-culturally and linguistically, and all relied on primary health centres and village health/malaria workers as the main providers of primary healthcare. These were generally bypassed by severely ill patients for urban first-level referral hospitals and private sector facilities. While >75% of villages were near primary schools, educational attainment was generally low. Over 70% of villages at each site had mobile phone coverage and availability of electricity was high (≥65% at all sites bar Myanmar). Conclusion These results illustrate the similarities and differences of villages in this region that must be considered in public health research and policymaking.
The impact of mass screening and treatment interventions on malaria incidence and prevalence: a retrospective analysis of a malaria elimination programme in eastern Myanmar, and systematic review and meta-analysis
Abstract Background Targeted interventions are often needed to accelerate malaria elimination efforts. Mass screening and treatment (MSAT) involves testing all eligible and consenting individuals in an area for malaria and treating all positive individuals simultaneously. However, there are concerns regarding the impact of MSAT. This study evaluates the impact of MSAT on malaria incidence in Karen State, Myanmar, using routine surveillance data, and investigates the impact of MSAT in other settings through a systematic review and meta-analysis. Methods To investigate the impact of MSAT in Karen State, we retrospectively analysed routine malaria surveillance data collected in 10 villages where MSAT was done in 2018. Pre- and post-MSAT malaria incidences were compared, and a negative binomial mixed-effects model was used to estimate the relative change in monthly incidence for each additional year since MSAT. To investigate the impact of MSAT in other settings, we searched Scopus, Ovid MEDLINE, and Web of Science (end date 11th July 2022) for studies assessing the impact of MSAT interventions on the incidence or prevalence of malaria infections. Studies were summarized, and a random-effects meta-analysis was performed on studies grouped according to study design and the comparator used to assess the impact of MSAT. Results In the 10 villages in Karen State, there was an overall reduction in P. falciparum incidence following MSAT (Incidence Rate Ratio 0.37; 95% CI: 0.19, 0.73). However, this is likely due to the ongoing impact of early diagnosis and treatment services offered in these communities, as shown by an overall reduction in incidence in the surrounding area. Results from nine studies identified in the systematic review demonstrate the variable impact of MSAT, which is likely influenced by a variety of factors, including intervention coverage and uptake, baseline malaria endemicity, and methods used for MSAT delivery. Conclusions This retrospective analysis and systemic review highlights the complexities behind the success of targeted interventions for malaria elimination. While these interventions are important drivers for achieving elimination goals, particularly in high-burden settings, it is important that various factors be considered when determining their suitability and how to optimize implementation.