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.

Sickle cell disease (SCD) is associated with chronic systemic morbidity that extends beyond acute crises. However, data describing the clinical and laboratory adolescents and young adults with SCD at steady state in sub-Saharan Africa are limited. We described clinical and laboratory characteristics of adolescents and young adults with SCD at steady state in Uganda. We conducted a hospital-based cross-sectional study of 60 adolescents and young adults with SCD in steady state at Mulago National Referral Hospital. Descriptive statistics were used to summarize participant characteristics and medication use. The mean age was 16.5 {+/-} 3.3 years, and 34 (56.7%) participants were female. Mean hemoglobin was 9.1 {+/-} 2.2 g/dl. Mean systolic and diastolic blood pressures were 107.9 {+/-} 15.5 mmHg and 60.3 {+/-} 12.6 mmHg, respectively; mean heart rate was 89.5 {+/-} 15.5 beats/min. Fifty-two (86.7%) participants reported using hydroxyurea. These observations show that adolescents and young adults with SCD at steady state exhibit hematologic abnormalities and distinctive hemodynamic profiles that underscore substantial chronic subclinical abnormalities that extend beyond acute complications.

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.

BackgroundRabies remains a persistent public health threat in India, while gaps in surveillance and coordination of control measures undermine progress towards ending human rabies deaths. The World Health Organization advocates a One Health approach, combining mass dog vaccination, post-exposure prophylaxis (PEP), and Integrated Bite Case Management (IBCM). IBCM is not yet incorporated into Indias national rabies action plan for rabies elimination (NAPRE). This study seeks to generate robust evidence on the effectiveness, cost-effectiveness, feasibility, facilitators and barriers of IBCM implemented within Keralas Rabies Control Program. MethodsThis will be an implementation-research, adopting a stepped-wedge cluster randomized controlled trial (RCT) design. IBCM will be implemented across six administrative blocks in Thiruvananthapuram District, Kerala, across diverse rural and urban settings, and including tribal population representation. The IBCM intervention includes stakeholder training and support, and active animal surveillance aligned with WHO guidance. Suspect or probable rabies exposures presenting at selected health facilities and identified via a community-based hotline will trigger investigations and responses including dog vaccination and sensitization. Prior to IBCM implementation, baseline data will be collected on management of dog bites, bite patient incidence and health case seeking behaviours. Hospital-based event tracking of bite cases will be conducted at enrolled public health facilities before and after IBCM implementation. The resulting RCT data will be used to model the impacts and cost-effectiveness of IBCM, including the potential for cost savings through judicious PEP, if scaled up across Kerala. To understand the barriers and facilitators to IBCM implementation, we will use in-depth interviews and focus group discussions with stakeholders. DiscussionThere is an urgent need to strengthen rabies surveillance, including coordination across health and animal health sectors and outbreak responses to accelerate rabies elimination. IBCM is expected to lead to improved PEP completion, increased detection and laboratory confirmation of rabid dogs, strengthened dog vaccination coverage, and targeted outbreak responses in high-risk areas. This RCT will provide critical evidence to inform policy, support scale-up, generate insights into contextual barriers and facilitators for IBCM implementation, and guide Indias One Health rabies elimination strategy. Unlike the Goa model that relies on hotline reporting, this study evaluates a health-sector-initiated IBCM approach that identifies cases through dog-bite patients presenting to health facilities, enabling more comprehensive One Health integration and greater event capture. Trial registrationCTRI registration No. REF/2024/04/081804

BackgroundFollowing three rounds of successful Indoor Residual Spraying (IRS) implementation in the district of Sakassou (Cote dIvoire), IRS was withdrawn and replaced by insecticide treated nets (ITNs). This study evaluated the entomological and epidemiological impacts of Interceptor (IG2) ITNs distributed in Sakassou, to determine if the protection offered by IG2 nets was adequate to suppress malaria transmission post IRS withdrawal. MethodsThe Vector Control Optimization Model (VCOM) was adapted to evaluate the effectiveness of the IRS and IG2 deployment on malaria transmission dynamics. Additionally, we used an interrupted time series (ITS) model to analyze routinely reported malaria cases in the district health Information Management System (DHIS2) to determine the epidemiological impact of both interventions. Counterfactual trends were generated for the post IRS withdrawal with IG2. ResultsThe results of the VCOM showed a 55.4% (95%CI, 48.3 - 62.4) reduction in the human biting rate (HBR) when IRS was deployed and 48.8% [95%CI, 42.8 - 54.6]) when IG2 nets were distributed, compared to standard pyrethroid-only nets. No statistical difference was recorded between the HBR of IG2 and IRS (p=0.164). Similarly, there was no statistical difference between the entomological inoculation rate (EIR) of IRS (64.7% [95%CI, 56.6 - 72.8]) reduction and IG2 (61.9% [95%CI, 54.2 - 69.6]) reduction (p=0.616). Furthermore, the ITS showed 26% reduction in malaria cases that was recorded immediately after spraying (IRR = 0.74; 95% CI: 0.62-0.90; p = 0.002) with cumulative impact over time and spray rounds and similarly to IG2 performance (IRR = 1.00; p = 0.200). ConclusionThe study findings suggest that IG2 nets provided comparable entomological efficacy as clothianidin-based IRS but could not adequately suppress malaria cases after IRS withdrawal which could be due to plastic vector feeding behaviour. This study provides evidence that dual AI ITNs such as IG2 may be warranted as a contingency strategy after IRS withdrawal but may require additional studies for full recommendation.

BackgroundSevere acute malnutrition (SAM) among children under 5 years of age is generally treated in outpatient settings providing caregivers with weekly ready-to-use therapeutic food (RUTF) rations to be administered at home. Recent updates to global treatment guidelines suggest that RUTF dose can be reduced once children progress to moderate stage (MAM). No evidence exists on the optimal timing of the dosage reduction or on ideal visit frequency. ObjectivesWe aimed to test the impact of 1) immediate RUTF dose reduction (1a) versus including a 2-week transition (1b) among children admitted with SAM and 2) fortnightly (2a) versus weekly (2b) visit frequency during MAM phase among children admitted with SAM and MAM. Methods and findingsThis prospective cluster-randomized controlled non-inferiority trial followed a 2 x 2 factorial design and divided 39 health areas (clusters) of Nara, Mali, into 4 groups implementing: A) 1a+2a B) 1a+2b, C) 1b+2a, and D) 1b+2b. Simplified, combined treatment was used providing 2 daily RUTF sachets to children admitted as SAM (mid-upper arm-circumference=MUAC<115mm or edema) and 1 daily RUTF sachet to children admitted with MAM (MUAC 115-124mm). Recovery was declared when a child reached MUAC [&ge;]125mm and absence of edema for 2 consecutive visits. Depending on the randomization arm, children admitted with SAM transitioned into receiving 1 daily RUTF sachet immediately upon reaching MUAC[&ge;]115mm (A+B) or after 3 consecutive visits (2 weeks) with MUAC[&ge;]115mm (C+D). Weekly visits were applied for all children with MUAC<115mm and then depending on randomization arm, visits continued weekly (A+C) or fortnightly (B+D) in the MAM phase. The main outcome was recovery and a non-inferiority margin of 10% was applied. Between April and December 2023, a total of 6249 children with MUAC<125mm or edema were admitted to treatment including 1451 children with SAM. On average 98% of children recovered with a mean duration of treatment of 6 weeks. Immediate transition resulted in non-inferior recovery compared to 2-week transition from SAM to MAM and no differences were observed in program outcomes (proportion of recovered, defaulted, non-recovered, transferred to inpatient care and deceased). However, we observed a non-significant trend of slight increase in the proportion of children regressing back to SAM after being MAM among children following immediate transition compared to those benefitting from 2-week transition. Fortnightly visit frequency in MAM phase resulted in non-inferior recovery compared to weekly visits throughout and no differences were observed in program outcomes. Duration of treatment was 2.5 weeks longer with fortnightly visits during MAM phase resulting in 23 sachets higher RUTF consumption compared to weekly visits throughout. ConclusionsWe recommend applying weekly visits throughout treatment where feasible for both children with MAM and SAM at admission and including a 2-week transition period before reducing the RUTF dose for children admitted with SAM once they reach MAM criteria. Trial registrationThe study was registered to clinicaltrials.gov (NCT06594341).

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.

BackgroundDengue fever, one of the most widespread mosquito-borne diseases, declined markedly during the early COVID-19 pandemic due to lockdowns and reduced mobility. However, the sharp resurgence in 2023 raised concerns about the long-term epidemiological effects of pandemic-era measures. This study examines the sustained impact of COVID-19 public health policies on dengue transmission across seven high-burden countries in Southeast Asia and Latin America. MethodsMonthly dengue cases and COVID-19 policy indices from January 2020 to December 2023 were analyzed in seven countries with [&ge;]2,000 dengue cases in 2020. Based on the Oxford COVID-19 Government Response Tracker (OxCGRT), countries were grouped as Strict COVID-Control (SCC: Singapore, China) or Less Strict COVID-Control (LSCC: Indonesia, Argentina, Brazil, Colombia, Mexico). Generalized linear models assessed lagged effects of the Stringency Index and policy sub-components, adjusting for climate and reporting bias. FindingsDengue cases declined by 41.3% (95% CI: 36.2-46.5; p < 0.001) in 2020 relative to pre-pandemic levels. In LSCC countries, public information and vaccination policies were significantly protective ({beta} = -174,354; p < 0.001), reflecting indirect benefits of COVID-19 awareness infrastructure. In SCC countries, economic interventions showed mixed effects: debt relief reduced dengue risk ({beta} = -0.783; p = 0.003), while income support increased it ({beta} = 0.583; p = 0.003). InterpretationCOVID-19 policies exerted lasting, heterogeneous effects on dengue transmission. Strengthening communication, vector control, and vaccination in LSCC settings, and maintaining vigilance and integrated surveillance in SCC settings, are crucial for sustainable dengue preparedness.

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.

Mexico has experienced increased dengue incidence in recent years, and there are concerns that the changing climate may enhance dengue transmission in the future. Whilst previous studies have characterised spatial heterogeneities in the long-term average risk of dengue infection in Mexico, the extent to which dengue transmission changes year-to-year has not been investigated. Furthermore, the extent to which dengues four serotypes may differ in their transmissibility remains poorly characterised globally. In this study we characterised the spatial and temporal variations in dengue transmission intensity, as defined by the force of infection, across 27 states in Mexico, by analysing the annual dengue cases reported to surveillance between 2016 and 2023 using established catalytic models and a new, serotype-specific extension of these models that characterises differences in the transmission intensity of the different serotypes. We found evidence of large spatial, temporal, and serotype-specific heterogeneities in transmission intensity across Mexico. Serotype-specific force of infection estimates suggest that DENV-1 and DENV-2 have historically circulated at high levels across Mexico, with DENV-4 transmission intensity low throughout the period studied. Model estimated DENV-3 transmission intensity increased in some states in recent years, coinciding with large outbreaks. This work quantifies serotype-specific differences in dengue transmission intensity using routinely collected case-notification data and demonstrates how extensive RT-PCR-testing and new rapid diagnostic tests capable of discerning infecting serotypes can help to better understand the contributions of different serotypes to transmission.

BackgroundMalaria is a major health issue in Ethiopia, particularly in rural and semi-urban communities. The approaches used to combat malaria transmission in Ethiopia emphasize on vector control methods. However, the effectiveness of malaria prevention efforts may be influenced by difference in social and demographic factors, populations knowledge and practices of malaria prevention. This study aimed to assess malaria prevention practices and associated factors among households in Bube Town, Oromia Regional State, Western Ethiopia. ObjectiveTo assess malaria prevention practices and associated factors among households in Bube Town, Oromia Regional State, West Ethiopia. MethodA community-based cross-sectional study design was employed, with data collected via a questionnaire administered by interviewers. A systematic sampling technique was implemented during data collection, and the data were analyzed using SPSS version 25 after being entered into EpiData version 3.1 software. Binary logistic regression statistical analysis was done to determine association between dependent and outcome variables. Factors with P < 0.25 in the bivariate analysis were included in the multivariate regression analysis and eventually variables with a P-value < 0.05 at a 95% CI were considered to have a significant association with malaria prevention practices. ResultsThe prevalence of good malaria prevention practices was 62.7% (95% CI: 58.0%-66.0%). Associated factors for good malaria prevention practices include higher age (above 25 years old), female sex (AOR=1.7, 95% CI: 1.035-2.295), knowledge of malaria breeding sites (AOR=3.7, 95% CI: 1.482-9.235), and knowing that malaria is preventable (AOR=4.014, 95% CI: 1.502-10.71). ConclusionMore than half of Bube town households had good malaria prevention practices. Good practices were associated with being older, female, knowing where malaria breeds, and knowing that malaria is preventable. Raising community awareness and developing targeted interventions for males and young family members are crucial to advancing malaria prevention strategies.

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.

Deaths due to diarrhea among children younger than five have been rapidly decreasing, from an estimated 484,781 in 2010 to 245,966 in 2021. A report by the International Livestock Research Institute in 2012 found that the top 13 most important zoonoses were responsible for 2.2 million human deaths. Questions remain whether the benefits of animal ownership outweigh the potential harms of being exposed to potentially deadly zoonotic pathogens. This study uses national surveys to assess the association between animal ownership and under-5 diarrhea in sub-Saharan Africa. Our outcome was a two-week reported prevalence of diarrhea. Information about animal ownership, socio-economic status (SES), age of children, and the familys primary water source were used in this analysis. We used Poisson regression with a log link to output prevalence ratios from a mixed-effects model. The study population included 680,752 children under the age of five who lived in rural areas in sub-Saharan Africa between 2005-2022. Our model showed a slight increase of two-week reported diarrhea among children whose families owned animals (PR: 1.02, 95% CI: 1.00, 1.04). Families who owned more animals reported a lower diarrhea prevalence (11.22%) compared to families who owned fewer animals (13.71%). Additionally, children whose families owned no animals had a diarrhea prevalence of 12.09%, compared to children whose families owned more than one species of animal (12.20%). Families who only owned pigs had a diarrhea prevalence of 15.31%. This study continues to highlight the complicated relationship between animal ownership and reported diarrhea prevalence. Further research needs to examine the role of animal ownership in the context of local weather patterns, especially after extreme precipitation events following extended dry period. There remains an open question whether the benefits of animal ownership outweigh the potential pitfalls, especially in consideration of climate change.

BackgroundDespite ongoing rabies control efforts in Arequipa, Peru--including mass dog vaccination campaigns and reactive ring interventions--the region has failed to reduce the number of rabid dogs, leading to the first reported human dog-mediated rabies case after 8 years. The gaps in the rabies control program and the complex dynamics among stakeholders are unknown. ObjectiveTo integrate epidemiologic, socio-ecological, and policy data to identify the factors contributing to the 2023 human rabies case and propose strategies to make this a never event. MethodsWe used stakeholder mapping and field quantitative and qualitative data to identify the roles and connections of key actors in rabies control, identifying gaps in their functions. We then applied the Swiss Cheese model to characterize the defense layers against dog-mediated rabies, highlighting critical vulnerabilities across these protective barriers. ConclusionsWe identified multiple breaches in the defense against dog-mediated human rabies. Weak surveillance, insufficient dog vaccination, and inadequate management of free-roaming and feral dogs, coupled with bureaucratic inefficiencies, were key gaps. Outbreak responses were delayed and insufficient, and access to post-exposure prophylaxis (PEP) remained limited. Communication breakdowns exacerbated the problem. Systemic issues, such as outdated public health policies, insufficient training of health professionals, and fragmented efforts, further hindered timely exposure response. Dog ecology and demographic factors also contributed to dog rabies spread. These failures in policy, response, capacity, and external factors led to the 2023 human rabies case. Despite awareness of these challenges, the contributing conditions remain unchanged. Eliminating dog-mediated human rabies by 2030 will require targeted interventions, including enhanced surveillance, context-specific policy reforms, stronger community and institutional collaboration, and better management of free-roaming dogs.

BackgroundSnakebite envenoming (SBE) remains a major neglected tropical disease in Sudan. Venom-induced consumption coagulopathy (VICC) is the most frequent and fatal systemic complication, particularly following envenoming by hemotoxic Echis species. Robust clinical data on VICC in Sudan are limited. MethodsWe conducted a prospective hospital-based cohort study at Sinja Teaching Hospital, Sennar state, Sudan, from March to September 2022. All patients admitted with SBE were enrolled. VICC was diagnosed using the 20-minute whole blood clotting test (WBCT20) and laboratory coagulation assays. Clinical features, laboratory abnormalities, management, and outcomes were recorded until discharge or death. ResultsAmong 119 patients with SBE (mean age 34.5 {+/-} 9 years; 79.8% male), VICC developed in 96 (80.7%). Echis spp. were implicated in 86.6% of cases based on patient recognition. Spontaneous systemic bleeding occurred in 88.5% of VICC patients, and life-threatening hemorrhage in 30.2%, most commonly intracerebral hemorrhage. Acute kidney injury occurred in 36.5% of VICC cases. WBCT20 was positive in all VICC patients and showed high diagnostic sensitivity. Despite administration of fresh frozen plasma, mortality among VICC patients was 30.2%. All paediatric patients died. ConclusionsVICC was highly prevalent and associated with severe hemorrhage, acute kidney injury, and high mortality in this snakebite-endemic region of Sudan. Supportive therapy alone was insufficient to prevent fatal outcomes, reflecting delayed presentation and the absence of effective Echis-specific antivenom. Improved access to species-appropriate antivenom, early referral, and adherence to evidence-based management are critical to reducing snakebite-related mortality in Sudan. Author SummarySnakebite envenoming is a neglected tropical disease that disproportionately affects rural and agricultural communities in low-resource settings. In Sudan, snakebite remains a major but underreported cause of illness and death. One of its most serious complications is venom-induced consumption coagulopathy (VICC), a disturbance of blood clotting that can lead to severe bleeding and organ failure. We studied all patients admitted with snakebite envenoming to a teaching hospital in southeastern Sudan over six months. More than 80% of patients developed VICC, most often following bites attributed to Echis species, which are common in this region. Many patients experienced spontaneous bleeding, and nearly one-third developed life-threatening hemorrhage, most frequently bleeding in the brain. Acute kidney injury was common. Despite supportive treatment, almost one-third of patients with VICC died, and all children in the study died. Our findings highlight the severe and largely preventable burden of snakebite envenoming in this setting. Delayed presentation to hospital, reliance on traditional healers, and the lack of effective antivenom against locally prevalent snake species contributed to poor outcomes. This study highlights the urgent need to improve access to appropriate antivenom, strengthen health-care systems, and implement evidence-based management of snakebite envenoming to reduce avoidable deaths and disability in Sudan.