Transactions of The Royal Society of Tropical Medicine and Hygiene

Background Acute malnutrition remains a major public health challenge among children under five in Malawi due to undetected and untreated cases. While several policies and programmes are in place, they face significant resource input and implementation constraints. In this study, we evaluate the potential health impact and cost-effectiveness of three interventions designed to address constraints along the care pathway in childhood acute malnutrition management. These include improving early recognition of symptoms by caregivers, increasing attendance at routine growth monitoring visits through community outreach, and scaling up the availability of therapeutic food supplements. Methods and Findings We use a newly developed model representing the natural history and management of acute malnutrition, implemented within the Thanzi La Onse (TLO) dynamic individual-based simulation framework, which captures the public health system in Malawi. Each of the three interventions is assessed both individually and in combination, translated into seven scenarios which we evaluate in comparison to the status quo. The optimal strategy combines two interventions, improved caregiver awareness of early symptoms with increased availability of therapeutic food supplements. Over five years, this strategy is predicted to avert 840,470 (95% CI: 682,057-998,883) DALYs with total incremental costs of $34 million. This corresponds to an annual health expenditure increase of $0.32 per capita. At a cost-effectiveness threshold of $76 per DALY averted, the strategy results in an incremental net health benefit of 394,252 (95% CI: 235,839-552,665) DALYs averted. Conclusions The cost-effective strategy for addressing constraints in childhood acute malnutrition management is simultaneously improving caregiver recognition of early symptoms and expanding therapeutic food supplement availability. Out of the seven scenarios evaluated, this integrated approach was found to be the optimal strategy within the Malawian public health system, yielding substantial health at modest costs. These findings provide critical evidence to inform national policy and guide investment prioritisation for the management of childhood acute malnutrition.

Childhood malnutrition remains a major public health challenge in Ethiopia, where stunting and wasting co-exist but may arise from distinct spatial and etiological processes. Analyses focusing on a single outcome may overlook the interdependence of these conditions and their geographic heterogeneity. This study aimed to disentangle the determinants of stunting and wasting among children under five years of age using a Bayesian bivariate spatial modelling framework. Data from 5,405 children included in the 2019 Ethiopia Mini Demographic and Health Survey were analyzed. Stunting and wasting were modelled as correlated binary outcomes using Bayesian bivariate hierarchical geostatistical models implemented through SPDE-INLA, accounting for child, maternal, household, and environmental covariates, non-linear age effects, and spatial dependence. Model performance was assessed using the deviance information criterion, Watanabe-Akaike information criterion, and marginal log-likelihood. The bivariate model identified shared socio-economic and biological determinants. Multiple births, male sex, low maternal education, a higher number of under-five children, and household poverty were associated with increased risks of both outcomes. Female-headed households were associated with lower odds of stunting but higher odds of wasting. Spatial analysis revealed elevated residual stunting risk in the northern and central highlands, whereas wasting hotspots were concentrated in northeastern pastoralist regions. Residual spatial correlation was weak ({rho} = -0.12), indicating largely independent geographic patterns. These findings suggest that effective child nutrition policies in Ethiopia require outcome-specific and regionally tailored interventions addressing both chronic and acute forms of malnutrition.

The spread of Anopheles stephensi into the Horn of Africa represents one of the main challenges for malaria control, given the species ecological plasticity and resistance to multiple insecticides. In response to the World Health Organizations 2022 vector alert, an adaptive, model-based spatial surveillance framework was developed and evaluated to improve detection, mapping accuracy, and operational responsiveness during invasion. Adaptive surveillance utilises initial observations to guide subsequent surveillance, linking the surveillance design to the underlying geographical characteristics of Anopheles stephensi distribution through observed data. This dynamic approach targets areas of high uncertainty and/or abundance, making the design responsive rather than predetermined. Focusing on Djibouti and selected regions of Ethiopia and Kenya, the adaptive surveillance was designed on previous in-country Anopheles stephensi surveillance data integrated with assembled open-source environmental, epidemiological, and demographic covariates. Key driver factors of the average monthly Anopheles stephensi catches varied geographically, although seasonality was universally important. Adaptive site allocation was optimised using a multicriteria target function which combines the trapping probability and uncertainty from previous surveys, with a simulation based on peaks-over-threshold (generalized Pareto) modelling of exceedances and Bayes factor-guided prioritisation. The selected adaptive surveillance design is the one that minimise the uncertainty in Anopheles stephensi trapping probability in hotspot areas. Optimal adaptive designs required between 50 to 59 sites per country, with uncertainty reductions in the probability of trapping projected up to 36% in Djibouti and more than 60% in Ethiopia and Kenya, with more than 60% site implementation halving uncertainty in Djibouti and Kenya and reducing it by up to 75% in Ethiopia. The proposed adaptive surveillance framework operationalises WHO guidance, accelerates hotspot identification, and inform targeted ecological studies and control interventions. It is extensible to other urban vectors (e.g., Aedes aegypti), enabling integrated, cross-border surveillance essential to contain Anopheles stephensi during ongoing invasion.

In 2024, mpox cases surged in the Democratic Republic of the Congo (DRC) with cross-border spread to Burundi. We developed a transmission-dynamic model calibrated against surveillance data to understand drivers in enzootic (Clade Ia) and non-enzootic (Clade Ib) areas, and the potential impact of vaccination. In non-enzootic areas we estimated that 58-84% of transmission occurred within sexual networks. MVA-BN vaccination of sex workers could have averted 91% (95% CrI 81%-98%) of infections in Sud Kivu (DRC) but only 35% (95% CrI 26%-47%) in Bujumbura (Burundi), due to later outbreak detection. In historically enzootic Equateur (DRC), ongoing zoonotic spillover best explained sustained incidence. There, pledged Lc18m8 vaccines could have averted 42% (95% CrI 40%-46%) of infections; prioritising children improved impact. Across all settings, doubling vaccine coverage by using a single dose of MVA-BN outperformed two-dose strategies. Timely detection and tailored vaccination strategies are critical to reducing mpox burden.

Progress in malaria control has stagnated since the early 21st century in many countries, requiring new approaches such as the use of spatially-targeted interventions. Evidence on the effectiveness of spatially-targeted interventions is mixed. Their success can be dependent on whether the setting is endemic, the metrics used to target the intervention, and the spatial resolution and scale of deployment. We developed a two-age-class, spatially-explicit model of malaria at the community-scale for a district in southeastern Madagascar, accounting for environmental heterogeneity and human mobility. The model was fit to field-based case notifications and malaria prevalence data and then used to simulate three interventions: indoor residual spraying (IRS), long-lasting insecticide-treated nets (LLIN), and active case detection (ACD). We compared five spatial targeting scenarios for each simulated intervention: (i) equally distributed, (ii) targeting communities nearest or (iii) furthest from clinics, (iv) targeting communities with highest incidence, and (v) targeting communities that are spatially central. The non-targeted intervention was generally the most effective, but the least resource efficient. The second most effective intervention was based on spatial centrality, which reached a larger population while using fewer transportation resources than the equally distributed. No combination of interventions was able to eliminate malaria in the district, although a "perfect" ACD intervention could avert 100% of severe malaria cases. These results highlight the potential for targeted malaria interventions, especially in low-income settings, that take into account spatial structure in the human population and mobility to reduce malaria burden using fewer resources than conventional district-wide interventions.

BackgroundPlasmodium vivax (P. vivax) has emerged as the primary cause of malaria in Cambodia. Achieving malaria elimination and securing malaria-free certification requires a focused effort on addressing P. vivax malaria. This is essential because the elimination of P. vivax often lags behind that of Plasmodium falciparum, making it a critical component in the overall strategy. This study assesses the feasibility of the Mass Drug Administration (MDA) and P. vivax Serological Testing and Treatment (PvSeroTAT) integrated with Reactive Case Detection (RACD) in two of the highest malaria burden operational districts of Cambodia and examines the potential for integrating these two approaches with existing malaria elimination efforts. MethodsThis study employs an observational, prospective cohort design. MDA with chloroquine (CQ) will be conducted in Stung Treng through four monthly rounds, while RACD with PvSeroTAT will be implemented in Sen Monorom, targeting households near confirmed P. vivax cases. Data on coverage, compliance, cost, and stakeholder perceptions will be collected through surveys, interviews, and malaria case monitoring. A Composite Feasibility Index will integrate quantitative and qualitative indicators. Cost and budget impact analyses will assess scalability for malaria-endemic districts. DiscussionInnovative and targeted public health approaches and tools are necessary to ensure the elimination of the malaria parasite reservoir, including the hidden hypnozoites. While MDA with CQ clears active blood-stage infections leading to immediate reductions in malaria prevalence, PvSeroTAT can detect past exposure to P. vivax by using serological markers allowing for targeted treatment of individuals at risk of developing relapsing infections with an 8-aminoquinoline. This helps reduce the parasite reservoir more efficiently. This study will provide insight into operational feasibility, implementation costs, community acceptance, and long-term sustainability. The findings will guide Cambodias malaria elimination efforts through improved surveillance and targeted interventions. Trial RegistrationOSF Preregistration: https://doi.org/10.17605/OSF.IO/5KZH7, retrospectively registered 15 October 2025.

Background The Hump-nosed pit viper is a recognized but neglected medically significant species causing morbidity and mortality, with non-availability of a specific antivenom. There are many gaps in our understanding of its envenomation, including burden, clinical syndrome, complications and management. Methodology The study is a retrospective sub analysis of the Prospective VENOMS registry and hospital records of Hump Nosed Pit Viper envenomation from a single tertiary care center in coastal Karnataka from May 2018 to March 2024. Epidemiology, syndrome, complications and treatment strategies have been described. A linear mixed model analysis was conducted to study the effect of different therapeutic interventions in combating venom induced consumptive coagulopathy (VICC) Principal Findings Of 46 cases, 24 patients had VICC. The most common complications were AKI (21.7%), TMA (10.9%) and stroke (4.4%). Anaphylaxis to ASV (23.9%) was the most common therapeutic complication. Therapeutic interventions included ASV, administration of blood products and therapeutic plasma exchange along with supportive care. The linear mixed model revealed that administration of blood products (p=<0.001) had the strongest influence on the INR value, however, often resulting in a transient decline in INR value. ASV (p=0.052) caused only marginally significant change in INR. The role of TPE could not be statistically inferred, however, individual cases with severe VICC improved without complications, therefore it required further study but can be considered in critical cases. Conclusions/Significance This study describes the syndrome of hump-nosed pit viper envenomation, while highlighting the urgent need for a species-specific antivenom, recommends treatment strategies that can be used in the interim. Additionally, geo-spatial mapping draws attention to hotspots and the hypothesis that HNPV in coastal Karnataka have regionally distinct toxicity trends.

BackgroundMalaria transmission in Uganda is heterogenous, so the national malaria program needs information about the distribution of malaria to develop appropriate policies. While population-based community surveys estimate Plasmodium falciparum parasite rate (PfPR), they are too infrequent and sparse for routine malaria management. Health facility data is routinely collected and covers a large geographic scope, but the data is collected passively, variable in quality, and potentially highly biased. We aimed to triangulate test positivity rate (TPR) from health facility data to survey estimated PfPR data in Uganda to create monthly, high-resolution PfPR estimates. MethodsUsing matched health facility and survey data, we fit a multi-level logistic regression model that accounted for clustering at the district and region level, to predict PfPR from TPR. Additional covariates were explored to select a final model that reduced bias while prioritizing its utility for programmatic tasks. Model predictions were validated against observed PfPR and used to generate monthly district-level prevalence estimates from 2016 to 2024. Regional and national level estimates were made by weighting district level estimates by population. ResultsThe final model included a smoothed TPR term and proportion of severe malaria cases at a district-month level. Predicted PfPR was strongly positively correlated with the observed survey PfPR (Pearsons rank correlation rho =0.79, p<0.001). National estimates derived from predicted PfPR aligned well with survey estimates from the same time and area. ConclusionHealth Management Information System (HMIS) data, when paired with research data, can be used to estimate malaria prevalence with high spatial and temporal resolution. Estimates can be tested and models can be updated to help malaria programs best leverage facility data. In the context of declining survey frequency, HMIS-based modeling offers a resilient and cost-effective alternative for malaria surveillance and programmatic decision-making in Uganda and similar high-burden settings.

Seasonal Malaria Chemoprevention (SMC) is a promising intervention for Turkana, Northern Kenya, where malaria transmission is highly seasonal. Traditional malaria control methods, such as indoor residual spraying (IRS) and insecticide-treated nets (ITNs), are impractical due to the populations semi-nomadic lifestyle, temporary dwellings, sparse settlements, and limited access to health facilities. In 2024, following the WHOs updated guidance on SMC use, this intervention was implemented in Turkana Central for the first time, involving five monthly cycles of sulphadoxine-pyrimethamine with amodiaquine (SPAQ). To assess the programs feasibility, a mixed-methods study was conducted at the end of the campaign. Survey data from a randomly selected, representative sample of 449 households with 680 eligible children were analyzed using multi-level logistic regression to compare partial versus complete SMC adopters, accounting for clustering. It was supplemented by qualitative interviews involving 45 caregivers to explore barriers and facilitators to SMC adoption. The campaign achieved notable success, with 97% of children receiving at least one SMC cycle (95% CI: 94-99%), and 71% receiving all 5 cycles (95% CI: 66-75%), primarily through door-to-door delivery. The quality of delivery was evident, as 99% of caregivers reported direct observation of the first dose and proper instructions for subsequent days. Adherence to day 2 and 3 medication remained high at 95% (95% CI: 93.5-98.1). Regression analysis suggested that households familiar with their Community Health Promoter (CHP) and who communicated SMC information had lower odds of missing cycles. In contrast, children from wealthier families showed a 93% higher odds of missing cycles. Qualitative findings revealed that positive caregiver experiences with SMC effectiveness drove continuation, while late adoption was linked to illness/ineligibility, uncertainty, and rumors. Overall, these findings indicate that high and sustained SMC coverage is feasible in marginalized settings through adaptive delivery strategies and leveraging of trusted CHP networks, establishing a scalable model for similar mobile populations.

BackgroundThe widespread insecticide resistance increasingly threatens malaria elimination, prompting a reassessment of vector control strategies. As Tanzania transitions from standard pyrethroid-only insecticide-treated nets (ITNs) to new-generation nets, evaluating the impact of this shift on malaria transmission and resistance is critical. MethodsUsing the agent-based malaria model, EMOD, we assessed the impact of three ITN types, standard pyrethroid-only nets, pyrethroid-PBO nets (Olyset(R) Plus/PermaNet(R) 3.0), and the dual active, Interceptor(R) G2 nets (IG2) on malaria transmission and the evolution of insecticide resistance. We also evaluated different sequences for introducing the new-generation nets, and the impact of combining ITNs with indoor residual spraying (IRS). The model was calibrated using incidence and prevalence data from two regions in northwestern Tanzania, incorporating seasonality, insecticide resistance, and behaviors of dominant vectors Anopheles funestus (highly anthropophilic, endophilic) and Anopheles arabiensis (more opportunistic readily biting non-human hosts outdoors). ResultsChanging from standard pyrethroid-only ITNs to pyrethroid-PBO and thereafter to IG2 ITNs reduced homozygous-resistant An. funestus and An. arabiensis by 62.2% and 92.8%, respectively, and reduced incidence and prevalence by 94% and 75.2% respectively, under conditions where the probability of mosquito pyrethroid resistance was 0.75. Deploying IRS before the peak malaria transmission season in mid-May, in the second year following pyrethroid-PBO ITNs distribution, and repeating this every three years, reduced malaria incidence and prevalence by 76.4% and 52%, respectively. ConclusionIn contrast to continuous use of standard pyrethroid-only ITNs, which sustains resistance selection, transitioning to new-generation ITNs, with or without periodic IRS, can disrupt the evolutionary trajectory of pyrethroid resistance, reduce malaria burden, and strengthen progress toward elimination.

IntroductionHemophagocytic lymphohistiocytosis (HLH) is a serious condition induced by Dengue virus which becomes fatal if not detected early and treated appropriately. So objectives of the present study are to observe the different patterns of presentations, clinical features and outcome of HLH induced by Dengue. MethodsIn this observational study, 14 patients admitted and diagnosed HLH as per diagnostic criteria, were included after informed written consent. Study conducted in a period of six months from 01/07/2025 to 31/12/2025. All patients were followed up till discharge. After collection, all data were analyzed by Microsoft Excel 2010. Ethical clearance was taken from Ethical Review Board of the Medical College. ResultsAmong 14 cases, male were more affected then the female (78.6% VS 21.4%) and majority were in between 20 to 50 years age groups. Clinical data showed, all 14 cases had fever for >7 days, joint pain 3(21.4%), headache 11(78.6%), skin rashes 10(71.4%), retro-orbital pain 2(14.3%), vomiting 11(78.6%),bleeding 10(71.4%), cough 4(28.6%), loose motion 9(64.3%), abdominal pain 7(50.0%), anorexia 2(14.3%), Melaena 2(14.3%), jaundice 4(28.6%) and spleenomegaly 9(64.3%). One(7.1%) case had history of Hypertension. Laboratory data showed different level of Bi or Pancytopenia, high ferritin, high TG, low fibrinogen, raised liver enzymes and low sodium. Dengue RT PCR and serology results showed 8(42.9%) cases were both IG M and Ig G dengue antibody positive, 6 cases were RT PCR positive, 2 cases were IgM and another 4 cases were IgG positive. Outcome of patients revealed, among all 14 cases12(85.8%) patients improved uneventfully and 2 were shifted to ICU where one improved and one died. ConclusionDengue is prevailing for long time and different complications are evolving and HLH is a relatively newer incident among the dengue patients. Infection by different serotypes at different time or multiple dengue serotype infection may be related with HLH and it might be a future subject to explore and to evaluate.

Programmatic decisions regarding surveillance and intervention for trachoma are made at the district level, reflecting an implicit assumption that transmission within districts is sufficiently homogeneous. However, as trachoma transmission declines, residual pockets of transmission may become spatially heterogeneous at sub-district scales. Using cluster-level data from 12 districts in Amhara, Ethiopia (2019-2023), we assess the spatial structure of Pgp3 antibody responses, a sensitive measure of infection transmission. Spatial clustering was evident in higher prevalence districts but diminished as populations approach elimination. We show that as districts approach elimination sub-district heterogeneity disappears, and district-level summaries are likely sufficient to guide decision-making.

BackgroundArtemisinin-based combination therapies (ACTs) are the most widely used treatment for Plasmodium falciparum malaria. Kelch 13 mutations associated with artemisinin partial resistance (ART-R) have emerged in Sub-Saharan Africa (SSA) and are now reported in an increasing number of countries. ACT treatment failure rates are at risk of unprecedented increase. To summarise existing surveillance data and guide future surveillance, we produce modelled estimates of the spatiotemporal distributions of Kelch 13 and partner drug marker prevalence in SSA. MethodsWe develop and validate spatiotemporal statistical models, fitted within a Bayesian framework, given molecular surveillance data. We estimate the prevalence of Kelch 13 mutations that are validated or candidate markers of ART-R and the prevalence of the mutations Pfcrt-K76T, Pfmdr1-N84Y, Pfmdr1-Y186F, and Pfmdr1-D1246Y, associated with selection by pressure from the ACT partner drugs amodiaquine and lumefantrine. FindingsOur models reflect all existing clusters of ART-R-associated Kelch 13 mutations. We estimate the prevalence of these Kelch 13 mutations to be greater than 10% in 23% of the area of endemic malaria transmission in SSA in 2026. We also estimate that 5.8% of malaria cases in 2026 will be affected by a validated or a candidate ART-R marker. Our estimates of the prevalence of Pfcrt-K76T and other partner drug markers reflect sustained pressure from artemether-lumefantrine: we estimate the median prevalence of Pfcrt-76T across SSA to be 19% in 2026. InterpretationOur models allow readers to visualise variation in observed mutation prevalences and to extrapolate prevalence to regions in space and time that are not represented in surveillance data. To monitor the changing distribution of antimalarial resistance markers within the constraints of the current global health funding climate it is critical that validated, statistical frameworks are incorporated into decision-making workflows to make the best use of molecular surveillance data. FundingThis research was funded by the European Union under the Global Health EDCTP3 Joint Undertaking (grant agreement 101103076) and the Australian National Health and Medical Research Council (APP2019093). Research in contextO_ST_ABSEvidence before this studyC_ST_ABSOngoing systematic reviews of molecular surveillance of antimalarial resistance markers collate evidence of changing prevalences of Kelch 13 mutations associated with artemisinin partial resistance. However, there is a high degree of sampling bias in this data, and there are regions where limited surveillance has been carried out. We searched PubMed with the search terms: (((spatial OR spatiotemporal) AND (artemisinin OR Kelch)) AND (Africa)) AND (model* OR map OR mapping) which returned 30 results. We identified one recent pre-print describing spatiotemporal models of molecular markers of ART-R and partner drug resistance, however these models were not formally validated and model uncertainty may have been under-estimated. Added value of this studyWe use spatiotemporal statistical models to estimate resistance marker prevalence in regions where there has been no molecular surveillance. Our models predictions are contextualised by estimates of model uncertainty, and we validate our modelling framework through posterior predictive checks and by evaluating its predictive performance on held-out data. Implications of all available evidenceKelch 13 mutation prevalences are rising in all existing clusters where mutations have been identified, including in southern Africa. We estimate elevated prevalences in regions that neighbour existing clusters that are not well-represented in our surveillance dataset.

The Global Polio Eradication Initiative (GPEI) is known to be one of the most successful disease eradication initiatives with massive reductions in polio transmission as well as its contributions to strengthening health systems and capacity building. Existing analyses provide limited insight into how capacity was developed, which forms of capacity were strengthened or neglected, and how these efforts were experienced by implementers. Understanding these factors can be helpful as GPEI accelerates transition and integration into national health systems. This study examines GPEIs capacity-building efforts from the perspectives of GPEI workers across multiple roles, levels and countries. We conducted a qualitative secondary analysis of semi-structured key informant interviews with global, national, and subnational stakeholders involved in GPEI. Data were coded inductively and deductively analyzed through Capacity Building Pyramid by Potter and Brough 2004. Country-based co-authors reviewed findings for contextual accuracy. We found that GPEI substantially strengthened individual and infrastructure capacity through large-scale training of frontline health workers, development of immunization infrastructure, and establishment of operational. Polio-funded platforms enabled outreach to hard-to-reach populations and were leveraged for other health priorities. Despite substantial investments, capacity building has remained largely individual training and program centric. There was insufficient integration into national systems leading to constrained country ownership and, lack of diverse trainings leading to limited supervisory and management capacity. Lessons of capacity building done under GPEI provide important guidance for future planning, and implementation of large-scale interventions. These findings highlight the need to move beyond predominantly individual-focused training toward deliberate, systems-level capacity strengthening. As polio transition planning accelerates, global health policymakers and planners must prioritize systems-level capacity strengthening, sustainable financing, and national governance to ensure continuity of immunization and public health functions beyond GPEI. Leveraging GPEI assets for broader health system strengthening can accelerate progress toward universal immunization and health care.

BackgroundChikungunya virus (CHIKV) is an Aedes transmitted arbovirus. Demographic changes coupled with the expanding footprint of the mosquito from climate change have the potential to shift the global burden from the virus. MethodsHere we use projections of human demography and Aedes mosquitoes distribution to estimate baseline and future burden from CHIKV under different climate change scenarios in 178 countries. We then estimate the potential of vaccines to mitigate the growing burden. FindingsWe found that under RCP2.6 (an optimistic climate change scenario), the global population at risk from CHIKV will increase by 30.2% to 5.4 billion individuals. We estimated a 35% increase in annual infections, 49% increase in cases and a 128% increase in deaths. A similar impact was found under the more pessimistic RCP8.5 climate change scenario. In Europe and the Americas, the growing presence of Aedes will drive the growing case burden, with increases in human population size being key elsewhere. Ageing populations will result in major increases in the number of CHIKV-related deaths in all continents outside Africa. Vaccinating 50% of individuals aged 12y+ with a vaccine providing 70% protection against disease and 40% protection against infection would avert 29% of cases and 31% of deaths. InterpretationThese findings highlight how climate change will expand the footprint of CHIKV circulation, while demographic changes will lead to substantially increased case burden in affected countries. Vaccines will be critical to minimising this changing global burden. FundingCEPI

Low participation in public health testing can lead to biased estimates of disease prevalence and inefficient allocation of public health resources. We evaluated the impact of monetary incentives and revisits on participation in door-to-door COVID testing in rural western Kenya. We conducted a cross-sectional study of all residents in 12 villages in rural western Kenya. We offered an incentive of KSh 200 (1.85 USD), KSh 350 (3.23 USD), or KSh 700 (6.47 USD), randomized at the household level, for each household member >3 months old who participated in COVID testing. Among 7,049 individuals, 5,659 individuals consented to testing. Overall, after revisits, 78.2% consented in the KSh 200 group, 80.6% in the KSh 350 group, and 81.9% in the KSh 700 group. Among individuals offered KSh 200, revisiting increased the consent rate from 68.1% to 78.2%, or 7.3 percentage points higher than the first visit consent rate in the KSh 700 group. Participation was very high (96.9%) among available individuals, but 17.2% of individuals were never available. Offering KSh 200 minimized the cost per consenting individual in our sample, even with revisits, compared to higher amounts. However, individuals in the KSh 700 group were slightly more likely to test positive, which suggests these individuals are missed at lower incentive amounts. Overall 0.3% (95% CI: 0.2, 0.5) tested positive for current infection by qPCR on nasal swabs, and 8.6% (7.7, 9.6) tested positive for SARS-CoV-2-specific antibodies by ELISA on dried blood spots. Accounting for nonresponse bias suggests this COVID population burden may be an underestimate. Our findings suggest incentives can increase participation in household door-to-door public health surveillance testing and may improve disease prevalence estimates by reducing nonresponse bias. However, high incentives may not be cost effective when low incentives motivate very high levels of participation. Significance StatementAchieving high levels of participation in testing can inform public health strategies for reducing the spread of infectious diseases. Cash incentives are one tool for increasing participation, but there is little evidence on the effectiveness of this approach in low-resource settings. We find that cash incentives increase participation in free COVID-19 testing in rural Kenya and may reduce nonresponse bias.

BackgroundZero-dose children, defined as those who have not received a first dose of a diphtheria-pertussis-tetanus (DPT)-containing vaccine, represent one of the sharpest manifestations of inequity in immunisation systems. Nigeria remains one of the largest contributors to the global zero-dose burden, with North-East Nigeria facing intersecting crises of conflict, population displacement, governance fragility, and weakened primary health care. Existing research has largely focused on structural determinants such as poverty, maternal education, and rural residence, with far less attention to relational mechanisms and governance dynamics that shape caregiver decisions. MethodsWe conducted a cross-sectional secondary analysis of the 2023 Nigeria Demographic and Health Survey (NDHS) Childrens Recode dataset. Weighted descriptive statistics and survey-adjusted logistic regression models were used to estimate zero-dose prevalence and identify structural and health system-contact determinants among children aged 12-23 months ResultsThe weighted national zero-dose prevalence was 37.1% (95% CI: 35.2-39.0), meaning more than one in three eligible children had never received a DPT-containing vaccine. The strongest independent predictors of zero-dose status were no ANC visits (aOR = 6.68, 95% CI: 5.52-8.09), no maternal education (aOR = 4.70, 95% CI: 2.89- 7.67), poorest wealth quintile (aOR = 2.79, 95% CI: 1.82-4.27), home delivery (aOR = 1.41, 95% CI: 1.18-1.69), and rural residence (aOR = 1.45, 95% CI: 1.18-1.75). Crude regional disparities were marked but attenuated after adjustment, suggesting that the apparent North-East effect is largely mediated through structural and service-contact pathways. ConclusionZero-dose status in Nigeria reflects deep structural exclusion and fragmented early contact with the health system, rather than isolated individual preferences. ANC utilisation and place of delivery emerge as pivotal touchpoints where health systems can either build or erode trust and continuity of care. These findings provide a quantitative foundation for future research exploring relational and contextual mechanisms shaping immunisation exclusion.

BackgroundMaternal immunization (MI) can prevent major infectious diseases in mothers and children by boosting the immunity of pregnant women. Antenatal care (ANC) delivery platforms could be leveraged to effectively provide MI. Adding MIs into ANC could potentially enhance ANC services, positively influencing both maternal and infant health outcomes and yielding broader benefits. We model these potential ANC-mediated health benefits in five low- and middle-income countries: Ethiopia, Ghana, Kenya, Pakistan, and South Africa. MethodsWe first developed a conceptual framework delineating pathways through which MI-ANC could enhance ANC utilization and quality, leading to improved care-seeking for facility delivery, postnatal care, and major childhood vaccinations (e.g., measles, diphtheria-pertussis-tetanus [DPT] third dose), as well as decreased infant mortality. Using a decision-analytic model informed by Demographic and Health Survey data, we simulated the potential benefits of MI-ANC delivery across socioeconomic groups at varying hypothetical MI coverage levels. ResultsMI-ANC integration would be associated with improvements in maternal and child health outcomes across all countries studied, mediated through enhanced engagement with ANC services. Under a scenario of full MI-ANC coverage, for example, infant mortality in Ethiopias poorest quintile was projected to decline from approximately 60 to 50 deaths per 1,000 live births. In-facility delivery rates were estimated to increase from 11% to 35%, postnatal care utilization from 4% to 11%, measles-containing vaccine coverage from 43% to 71%, and DPT3 immunization from 36% to 63%. These improvements would vary substantially by country and socioeconomic group, with the largest gains observed in populations with lower baseline ANC utilization. ConclusionsIntegrating MIs into ANC services has the potential to yield ANC-mediated health benefits, particularly in settings with low baseline ANC utilization. These findings can help inform priority-setting, support the design of targeted pilot programs, and guide future empirical implementation research on the possible broader impacts of MI-ANC delivery.

Iron deficiency (ID) is the most common nutritional deficiency worldwide, often caused by insufficient dietary intakes. Oral supplementation is one of the means to improve iron status. This study evaluated the efficacy and safety of two low-dose iron supplements - >Your< Iron Forte Capsules (YIFC) and Ferrous Sulfate Capsules (FSC) - in individuals with dietary ID. One hundred and one participants (mean age 30.6 years; 98% women) with low iron stores (mean serum ferritin 16.1 {micro}g/L) were randomized to receive either YIFC or FSC once daily for 12 weeks. Changes in blood indices and iron-related parameters were assessed at four and 12 weeks of intervention relative to baseline. The primary outcome was the change in hemoglobin (Hb) after 12 weeks. Eighty-seven participants completed the study. Both supplements significantly increased Hb at 12 weeks (YIFC: mean 6.52 g/L, p<0.001; FSC: mean 5.71 g/L, p<0.001). Product-related adverse events (AEs) were few (17% of all AEs) and of mild to moderate intensity only. One participant receiving FSC withdrew due to a probable product-related AE. The frequencies of product-related AEs were similar between study arms, however, statistically significantly more AEs judged to be definitely related to the product occurred in in the FSC arm. While product-related AEs were confined to the gastrointestinal tract in the YIFC arm, they affected multiple organ systems in the FSC arm. Supplementation with either YIFC or FSC proved as an effective, well-tolerated, and safe strategy for improving iron status in non-anemic dietary iron deficiency. In terms of the AE profile, supplementation with YIFC may offer advantages over supplementation with FSC.

IntroductionNational surveys in Pakistan are typically representative only at national or provincial levels, leaving large uncertainties in district-level contraceptive prevalence. This obscures local heterogeneity and limits data-driven program planning. Administrative data, although more frequent and detailed, are often underused due to reporting and measurement challenges. This study develops a multi-source small area estimation (SAE) framework to generate district-level estimates of contraceptive prevalence rate (CPR) and modern contraceptive prevalence rate (mCPR) using routine commodities data. MethodsA two-stage Bayesian SAE model was constructed to integrate survey, supply, and census data. In Stage 1, contraceptive dispensation data from the Contraceptive Logistics Management Information System (cLMIS) were converted into inferred users, normalized to married women of reproductive age (MWRA) from the 2023 Census, and scaled to provincial CPR benchmarks from the Pakistan Social and Living Standards Measurement Survey (PSLM). In Stage 2, a bivariate hierarchical Bayesian model jointly estimated CPR and mCPR, accounting for measurement error and borrowing statistical strength from socioeconomic and demographic covariates. Convergence and model stability were assessed through standard diagnostics (R-hat, ESS, BFMI, divergence checks). ResultsDistrict-level estimates were produced for 121 districts. CPR ranged from 9% to 46% and mCPR from 6% to 35%. Aggregated provincial estimates were consistent with PSLM benchmarks (within {+/-} 0.6 percentage points). Comparison with published district studies showed mean absolute deviations around 4 percentage points. ConclusionThe Bayesian SAE framework generates statistically coherent, high-resolution contraceptive prevalence estimates, substantially improving visibility into geographic inequities in Pakistans family planning landscape. These granular metrics offer policymakers an actionable basis for prioritizing underserved districts and tailoring context-sensitive interventions.