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The American Journal of Tropical Medicine and Hygiene

American Society of Tropical Medicine and Hygiene

Preprints posted in the last 7 days, ranked by how well they match The American Journal of Tropical Medicine and Hygiene's content profile, based on 68 papers previously published here. The average preprint has a 0.06% match score for this journal, so anything above that is already an above-average fit.

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Spatiotemporal Mapping of Point-of-Care Diagnostic Accessibility: A Data-Driven Pipeline for Point-of-Care Distribution Analysis in Western Uganda

Bergman, D.; Nyehangane, D.; Besancon, L.; Podkorytova, M.; Tsoumari, V.; Staikoglou, D.; Kimuli, A. N.; Richard, M. R.; Ogwok, P.; Nankoma, C.; Alfven, T.; Mwanga-Amumpaire, J.; Gaudenzi, G.

2026-09-01 public and global health 10.64898/2026.08.28.26361594 medRxiv
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All primary healthcare centers owned by the Ugandan government in the Western Region of Uganda were submitted to a questionnaire concerning current availability of POCT from the Essential diagnostic List 2 part 1a and 1b, and the African laboratory inventory done by African Society of Laboratory Medicine and AfricaCDC. The data from the questionnaire was then linked to open source geodata provided by TomTom, and population data to calculate and visualize the accessibility of captured POCT. Findings: Availability of POCT Malaria is almost 100%, HIV 68-90%, and >30% for a majority of the POCT in the EDL-2 panel. 90% of the population in Western Region live within 1 hour by car from most of the essential POCT. Figures in the complementary web-based application visualize the accessibility of POCT for Western Uganda. Diagnostic deserts are visualized. Interpretation: Access to POCT at primary health care facilities in western Uganda has expanded substantially over the past decades. The geo-mapping tool presented here could inform policy decisions on strengthening diagnostic capacity at the national, regional, and provincial level. Funding: Swedish Research Council and Infravis All supplementary materials and a preprint of this submission are available on our OSF repository https://osf.io/j7puk/.

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A mechanistic statistical model of dengue dynamics in an endemic region

Luna-Martinez, N.; Cruz-Rodriguez, E. X.; Bernal-Castro, E. A.

2026-09-03 epidemiology 10.64898/2026.09.01.26361961 medRxiv
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Background Dengue is a major public health challenge, and predictive models are crucial for early warning systems. However, many current modeling practices rely exclusively on climatic factors or employ complex algorithms that lack the interpretability needed for informed public health decision-making. To address these shortcomings, we developed and validated a multidimensional, interpretable statistical model to predict monthly dengue incidence. Methodology/Principal Findings We used a Generalized Linear Mixed Model (GLMM) with a Negative Binomial distribution to analyze 14 years (2010-2023) of spatiotemporal data from 37 municipalities in Huila, Colombia, an endemic region. The model integrates non-linear and lagged effects of climatic, demographic, and socioeconomic factors. The final model underwent rigorous external validation on an independent test set (2021-2023). Our model demonstrated high predictive discrimination (R2 = 0.743, Spearman's {rho} = 0.657), accurately capturing the timing of epidemic outbreaks. Key findings include the identification of an optimal thermal window for transmission at 27-28{degrees}C, a threshold effect for precipitation above 800 mm, and a saturation dynamic in outbreak autocorrelation. Conclusions/Significance This mechanistically-informed statistical approach provides a robust and transparent tool for epidemiological surveillance, successfully balancing high predictive performance with the explanatory power needed for effective, data-driven public health interventions.

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Usability, acceptability and feasibility of continuous glucose monitoring among children and adolescents with type 1 diabetes in Kenya

Amolo, P.; Mungai, L.; Karume, A. K.; Kibugi, J.; Mwende, W.; Botella, N.; Haldane, C.; Kamau, Y.; Marban-Castro, E.

2026-09-01 endocrinology 10.64898/2026.08.27.26361447 medRxiv
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Introduction Continuous Glucose Monitoring (CGM) is considered standard care in high-income countries. There is, however, limited published evidence on CGM use in low- and middle-income countries. The purpose of this study was to assess the usability, acceptability, and feasibility of CGM use among people living with type 1 diabetes (T1D) and caregivers in a low-resource setting. Research Design and Methods This prospective study conducted at the Kenyatta National Hospital purposively enrolled persons aged 4-25 years who had been on management for T1D for at least six months, and caregivers of those under 18 years. Fourty youth living with T1D used CGM for three months in place of self monitoring of blood glucose (SMBG). The System Usability Scale (SUS), a Theoretical Framework of Acceptability-based questionnaire, the Diabetes Distress Scale (DDS), the Glucose Monitoring Satisfaction Survey (GMSS), and a feasibility survey were administered. Outcomes were summarized descriptively, including means, medians, and frequencies using R statistical software. Results The median SUS score was 98.8 (IQR 92.5-100.0). Acceptability was high, and the median total GMSS score improved from 3.73 to 4.73. Among adolescents and adults, the median overall DDS score reduced from 1.54 to 1.36, with reductions in scores in all domains, except for hypoglycemia distress which increased, and physician distress which remained low. Among caregivers, the median overall DDS score declined from 2.05 (moderate distress) to 1.90 (low distress), with modest reductions in teen management and parent-teen relationship distress and a slight increase in personal distress. Median CGM active wear time was 89%. Conclusion This study comprehensively evaluated CGM across usability, acceptability, and feasibility outcomes, with the findings supporting the integration of CGM into routine diabetes management in low-resource settings. The short follow-up period, however, may not capture changing perceptions or long-term adherence.

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Location-allocation modeling identifies strategic health facilities to expand access to snakebite antivenom in the Brazilian Amazon

Garcia Campos, M. A.; Rocha, T. A. H.; Perez de Souza, J. V.; Murase, L. S.; Murta, F.; Sartim, M. A.; Sachett, J.; Seabra de Farias, A.; Azevedo Machado, V.; Wen, F. H.; Staton, C. A.; Monteiro, W. M.; Gerardo, C. J.; Nickenig Vissoci, J. R.

2026-08-31 public and global health 10.64898/2026.08.28.26360696 medRxiv
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Background: Snakebite envenoming is a major cause of preventable death and disability in the Brazilian Amazon, where long distances, sparse roads, and dependence on river transport delay access to antivenom. We developed location-allocation models to identify community health centers that could strategically expand access to antivenom in Amazonas State, Brazil. Methodology/Principal Findings: We conducted an ecological geospatial study using a 2025 WorldPop population surface, locations of existing and candidate health facilities, and a multimodal road-and-river transportation network derived from OpenStreetMap and HydroSHEDS. Population demand was represented by 7,065 populated centroids, including 1,586 within Indigenous territories. We applied a maximize-coverage algorithm with a six-hour travel-time threshold. Two models were developed: one for Amazonas excluding Manaus and one for populations living in Indigenous territories. Both models began with 77 facilities already providing antivenom and progressively added candidate community health centers until coverage gains plateaued. The plateau occurred at 110 facilities, corresponding to 33 additional centers. In the model excluding Manaus, this configuration covered 1,118,831 people, or 75.11% of the target population; 87.61% of those covered could reach care within three hours. In Indigenous territories, coverage increased from 50.55% to 69.50%, reaching 50,434 people, of whom 81.39% were within three hours of care. Validation used 3,595 snakebite notifications from the 30 highest-burden municipalities in the Brazilian Notifiable Diseases Information System during 2023-2025. The median proportion reaching care within six hours was 40.81% in observed data and 72.17% in model estimates. Conclusions/Significance: Strategically equipping 33 additional existing community health centers could substantially expand timely access to antivenom, particularly in rural and Indigenous areas. Location-allocation modeling that incorporates river transportation can support evidence-based decentralization of time-sensitive health services in geographically complex settings.

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Case Fatality of Leptospirosis in the Dominican Republic, 2012-2026: A 14-Year National Surveillance Analysis

Sanchez, J. J.; Alcantara, L. V.; De Luna, D.; Aleuy, O. A.; Bellon, M. B.; Cruz Raposo, J. L.; Dye, T. D. V.

2026-09-03 epidemiology 10.64898/2026.09.01.26361950 medRxiv
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Background: Case fatality reflects the quality and timeliness of clinical care for leptospirosis, yet no study has examined it at a national level in the Dominican Republic (DR), where leptospirosis is endemic. We describe the case fatality rate (CFR) of leptospirosis in the DR between 2012 and 2026 and identify associations with mortality. Methods: We conducted an analytical cross-sectional study, using national surveillance records merged with a discharge-condition extract via a composite key. We calculated CFR with Wilson 95% confidence intervals among 5,412 valid cases (suspected, probable, or confirmed) reported from January 2012 through June 2026. We compared proportions with Pearson's chi-square test, assessed annual trend with ordinary least squares linear regression, and fitted multivariable logistic regression models to account for confounding. Results: Overall CFR was 8.5% (460/5,412), with no significant annual trend (p=0.372). CFR was higher in men than women (p < 0.001) and increased significantly with age (p < 0.001). Male gender (OR: 1.79; 95%CI: 1.18-2.73) and pre-existing comorbidity (OR: 1.76; 95% CI: 1.21- 2.57) were independent predictors of death. Clinical complications were the strongest predictor in the adjusted model (OR: 3.16; 95%CI: 2.17-4.61), attenuating the gender effect. CFR varied widely by province (2.43-22.22%) and correlated negatively with incidence at the province level (p = 0.066). Conclusions: Leptospirosis case fatality is concentrated among men, people with comorbidity, and those who develop clinical complications. These national, long-term findings can help prioritize clinical and surveillance resources as extreme weather events are expected to intensify across the Caribbean.

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Antimicrobial resistance genomics across Africa: critical determinants, repository bias and regional coordination

Omani, R.; Maina, G. N.; Fasina, F. O.

2026-09-02 public and global health 10.64898/2026.08.31.26361859 medRxiv
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Public genomic repositories can support antimicrobial resistance (AMR) surveillance, but unequal sampling can bias interpretation. We characterised AMR determinants, multicountry genomic cluster overlap and surveillance gaps across Africa using an NCBI Pathogen Detection snapshot retrieved on 24 August 2026 for 55 African Union member states. Records were validated and deduplicated by BioSample, and complete AMRFinderPlus calls were summarised across five United Nations M49 subregions and eight overlapping regional economic communities (RECs). Country-pair cluster overlap was assessed using the Jaccard index, while project-based and composition-standardised sensitivity analyses evaluated repository bias. The dataset contained 86,829 unique BioSamples from 51 states; South Africa, Malawi and Kenya contributed 55.8%. Complete extended-spectrum {beta}-lactamase calls were detected in 21,513 isolates and carbapenemase calls in 4,642. blaCTX-M-15 dominated the ESBL profile, while NDM and OXA types predominated. Seventy clusters contained carbapenemase-positive isolates from at least two countries. A shared REC covered all participating countries in 38 clusters, while 32 crossed REC boundaries. Normalised country-pair overlap was low, with a maximum Jaccard index of 9.5%. Project balancing reduced the Northern African carbapenemase estimate from 32.3% to 17.9% and the Eastern African ESBL estimate from 36.9% to 12.5%. Public repositories identify determinants and clusters for investigation but do not estimate prevalence or transmission. AMR surveillance should combine national confirmation, regional institution-led investigation where countries share an REC, and continent-wide coordination through Africa CDC for cross-REC signals, supported by representative One Health sampling, standardised metadata and sustained African sequencing capacity.

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Access to malaria diagnosis and treatment in Zambia in the context of scaling-up community case management: results from repeated national cross-sectional surveys

Mao, Z.; Bennett, A.; Silumbe, K.; Miller, J. M.; Millar, J.; Slater, H.; Yukich, J. O.; Ashton, R. A.; Kyomuhangi, I.; Andrada, A.; Karabo, R.; Eisele, T.

2026-08-31 public and global health 10.64898/2026.08.25.26361362 medRxiv
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Background: Community case management has been scaled up nationally in Zambia over the last decade. However, there is limited evidence on how this nationwide implementation has affected febrile patients' access to malaria diagnosis and treatment in Zambia. Methodology: This study analyzed four rounds of Malaria Indicator Survey (MIS) data (2012-2021) to evaluate: 1) proportion of all-ages individuals with fever who sought treatment from a formal provider, 2) proportion of individuals going to CHWs over time, among those who sought treatment at a formal provider, 3) time duration between fever onset and treatment seeking at a formal provider, and 4) proportion of children <5 with malaria that received Artemether-Lumefantrine (AL) treatment. Mixed-effect logit models were employed to examine determinants of treatment-seeking behavior and factors affecting AL receipt among children <5 with malaria cases. Results: The proportion of febrile patients seeking treatment remained below 60% throughout 2012-2021, and AL receipt among children with malaria cases consistently stayed below 50%. The mean interval between fever onset and initial treatment-seeking encounter decreased from 2.42 days in 2012 to 1.71 days in 2021. Among formal care seekers, CHW utilization increased from 1.5% in 2012 to 10.0% in 2018 before declining to 3.2% in 2021. Longer walking time to the nearest health facility was associated with lower odds of treatment seeking, whereas CHW density was not associated with treatment seeking or AL receipt. Children who did not went to formal providers had lower odds of AL receipt than those who sought treatment from CHWs. Conclusion: Despite nationwide CCM scale-up over the last decade, significant barriers persist in malaria patients' access to diagnosis and treatment in Zambia. Our results indicate that while CCM coverage should be maintained and further expanded, additional complementary interventions are also needed to overcome remaining access barriers.

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Acceptability, feasibility, quality of life and diabetes distress score outcomes: A pragmatic randomised clinical trial on continuous glucose monitoring for people with type 1 diabetes

Marban-Castro, E.; Muhwava, L.; Girdwood, S.; Kemp, T.; Freitas, J.; Kamau, Y.; Otieno, M.; Akach, D.; Morato, A.; Sanz, S.; Fiechter, V.; Erkosar, B.; Watson, M.; Vetter, B.; Haldane, C.; Shilton, S.; Rheeder, P.; Dave, J. A.; Carrihill, M.; Karsas, M.

2026-08-31 endocrinology 10.64898/2026.08.26.26361479 medRxiv
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Introduction: Continuous glucose monitoring (CGM) offers an advancement over traditional self-monitoring of blood glucose (SMBG) for people living with type 1 diabetes (T1D). However, evidence on the acceptability and feasibility of different CGM use cases in African populations remains limited. Methods: This was a pragmatic three-arm, randomised controlled trial on CGM conducted among people living with T1D in three public healthcare clinics in South Africa. Participants were assigned to Arm 1 (continuous CGM), Arm 2 (periodic CGM), or Arm 3 (SMBG). Diabetes education was provided at all study visits. Feasibility was assessed by adherence to CGM use and through the Glucose Monitoring Satisfaction Survey (GMSS). Diabetes distress was measured by the Diabetes Distress Scale (DDS), health-related quality of life (HRQoL) by the EQ-5D scales, and acceptability using the Theoretical Framework of Acceptability (TFA). Surveys were collected on paper and transferred to OpenClinica. Analyses were performed in R. The trial was registered in the Clinical Trials Registry (NCT05944718) on July 13, 2023. Results: A total of 83 participants were included in Arm 1, 85 in Arm 2, and 80 in Arm 3. CGM mean active time was 55% in Arm 1 versus 69% in Arm 2. The proportion of participants meeting the [&ge;]70% active time threshold was higher in Arm 2 (52%) than in Arm 1 (34%). Diabetes' distress declined across arms during the intervention period, with no significant difference between arms; distress increased slightly six months post-intervention but remained below baseline. At 6 months, glucose monitoring satisfaction was significantly higher in both CGM arms than in the SMBG arm, and satisfaction increased over time in CGM arms. Health-related quality of life remained stable across arms during the intervention period with no significant difference between arms. High acceptability was observed in both CGM arms, with higher ratings in the periodic arm. Conclusions: CGM was acceptable to people living with type 1 diabetes and feasible to use in public-sector clinics in South Africa, with high acceptability under continuous and periodic use. Health-related quality of life remained stable across arms, and diabetes-related distress declined, during the intervention period, across arms. Glucose monitoring satisfaction rose significantly in both CGM arms compared to SMBG. Periodic CGM might be a promising and potentially more scalable option than continuous use for public-sector care.

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Characterizing the Burden of Scrub Typhus in Nepalese Children using Representative School-Based Cross-Sectional Serosurveys

Naga, S. R.; Shahi, S. B.; Gosai, S.; Maharjan, M.; Katuwal, N.; Morrison, E.; Andrews, J.; Shrestha, R.; Tamrakar, D.; Aiemjoy, K.

2026-08-31 infectious diseases 10.64898/2026.08.28.26361601 medRxiv
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Background Scrub typhus, an acute bacterial infection caused by Orientia tsutsugamushi, is an important, under-recognized etiology of febrile illness in South Asia. Accurate surveillance for scrub typhus in Nepal is challenging due to non-specific symptoms and limited diagnostic tools. Methods We conducted a representative school-based cross-sectional serosurvey in Kavrepalanchok and Dolakha, Nepal between November 2021 and April 2022 using two-stage sampling, we randomly selected 13 public schools and then up to 100 children aged 4-18 years per school. We collected capillary blood samples and tested for IgG responses to Orientia tsutsugamushi-derived recombinant 56-kDa antigen using commercially available ELISA kits. We estimated seroincidence rates using previously-published models of antibody decay dynamics from confirmed scrub typhus cases. We compared seroincidence to seroprevalence estimates using cutoffs derived from Gaussian finite mixture models applied to the study population. Results We enrolled a total of 827 children (participation rate: 94.8%). The median age was 10 years (IQR: 8-13), and 53.08% of the participants were female. The overall seroincidence rate was 6.3 new infections per 1000 person-years (95% CI: 4.7- 8.4), and the rate was slightly higher in peri-urban Kavrepalanchok (7.3; 95% CI: 4.9 - 10.3) compared with rural Dolakha (5.3; 95% CI: 3.3 - 8.5). Seroincidence increased with age, from 3.6 new infections per 1000 person-years (95% CI: 1.4- 9.7) among children aged 4- 7 years to 9.4 (95% CI: 6.2-14.3) among children aged 14-18 years. Seroincidence was higher in females (8.3; 95% CI: 5.9 -11.8) than in males (4.1; 95% CI: 2.4 - 6.9) (p=0.02). The overall seroprevalence was 6.5% (95% CI: 4.9-8.4) and followed a similar age and geographic trend to the seroincidence rate. Discussion Our findings reveal a substantial burden of pediatric scrub typhus in the Kavrepalanchok and Dolakha districts of Nepal. Seroincidence increased with age and was higher among females. School-based serosurveys offer an efficient sampling frame to rapidly assess population-level scrub typhus transmission intensity among children and adolescents, though may not represent out-of-school populations.

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Pharmacovigilance organization and training needs of health personnels in health facilities of Cameroon: a cross-sectional study

MURHABAZI BASHOMBWA, A.; TCHIO-NIGHIE, K. H.; NANA DJAPOU, M. C.; BUH NKUM, C.; BLAMA ABBA, I.; BEKOLO, C. E.; ATEUDJIEU, J.

2026-08-31 public and global health 10.64898/2026.08.26.26361382 medRxiv
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Health facilities (HFs) routinely administer medicines and are expected to ensure patient safety by detecting, reporting, investigating, and analysing adverse events following exposure to drugs (AEFED). This study aimed to assess the implementation of pharmacovigilance activities in referral and regional health facilities in Cameroon and to identify pharmacovigilance training needs among healthcare personnel (HP). This was a cross-sectional descriptive study targeting referral and regional health facilities and healthcare personnel involved in patient care and pharmacovigilance activities in Cameroon. Health facilities were selected using stratified purposive sampling, while healthcare personnel were selected through exhaustive sampling. Data were collected using semi-structured electronic questionnaires administered face-to-face by trained enumerators. The questionnaires assessed the organization, resources, and implementation of pharmacovigilance activities at health facilities, as well as healthcare personnel knowledge of pharmacovigilance concepts, previous training, and perceived training needs. Of the 14 eligible health facilities, 10 (71.4%) consented to participate in the study. Of the 10 health facilities, 4 (40.0%) had an established pharmacovigilance unit, while 3 (30.0%) reported conducting neither detection nor notification activities. Among the 261 healthcare personnel approached, 214 (81.9%) participated. Only 41.6% had needed knowledge to detect an adverse event, while 72.9% were aware of adverse event notification procedures. Previous exposure to pharmacovigilance training was reported by 37.9% of healthcare personnel, and all participants expressed a need for additional training, particularly on national pharmacovigilance regulations (69.2%), organization of the pharmacovigilance system (67.3%), and adverse event detection (67.3%). The main reported challenges by healthcare personnel in the implementation of pharmacovigilance activities included insufficient budget allocation, limited access to pharmacovigilance training, lack of pharmacovigilance guidelines and insufficient qualified human resources. Pharmacovigilance implementation in referral and regional health facilities in Cameroon remains limited, with gaps in organizational structures, resources, healthcare personnel knowledge, and training. Strengthening pharmacovigilance systems through improved facility capacity, availability of essential tools, and targeted healthcare personnel training is needed to enhance drug safety surveillance.

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Female contraceptive cover duration for miltefosine-containing regimens for the treatment of women with leishmaniasis

Chu, W.-Y.; Alves, F.; Dorlo, T. P. C.

2026-09-02 infectious diseases 10.64898/2026.08.31.26360682 medRxiv
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Introduction Miltefosine is the only approved oral antileishmanial agent, but its use in women of childbearing potential (WOCBP) is restricted due to preclinical teratogenicity. Current labeling recommends contraception during treatment and for at least five months thereafter, based solely on its long terminal elimination half-life. This study re-evaluated the required contraceptive duration using an exposure margin-based approach. Methods Virtual populations were generated from anthropometric data of 382 Indian, 4,462 Eastern African, and 4,019 Brazilian WOCBP with leishmaniasis. Published population pharmacokinetic models were used to simulate miltefosine exposure following 14-42-day regimens for visceral leishmaniasis (VL), post-kala-azar dermal leishmaniasis (PKDL), and cutaneous leishmaniasis (CL). A developmental safety exposure threshold was derived from the rat no-observed-adverse-effect level (0.6 mg/kg/day for 10 days) and adjusted using a 10-fold safety margin. Contraceptive durations resulting in median residual post-contraception exposure (AUCEOC-{infty}) below this threshold were considered supportive of contraceptive discontinuation. Results The developmental safety exposure threshold was estimated at 2.5 mg{middle dot}day/L. Despite pharmacokinetic differences across geographical regions and disease manifestations, required minimum contraceptive durations were consistent: three months from treatment initiation for the 14-day regimen, four months for 21- and 28-day regimens, and five months for the 42-day regimen. For the 14-day regimen, a single dose of a long-acting injectable contraceptive administered at treatment initiation would provide sufficient coverage. Conclusion An exposure margin-based approach supports shorter contraceptive durations than current recommendations. For the 14-day VL regimen, three months of contraception may provide a practical alternative to current labeling.

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Evaluating the roles of weather and bird dynamics in accurately forecasting West Nile virus infection in mosquitoes and humans

Oshinubi, K.; Covington, J.; Busser, N.; Townsend, J.; Will, J.; Ruberto, I.; Kretschmer, M.; Chen, Y.; Doerry, E.; Hepp, C. M.; Mihaljevic, J. R.

2026-08-31 epidemiology 10.64898/2026.08.27.26361564 medRxiv
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Mosquito-borne diseases pose a growing public health challenge as climate change reshapes vector population dynamics. West Nile virus (WNV), transmitted between birds and Culex mosquitoes, disproportionately affects Maricopa County, Arizona, one of the nation's highest-burden counties, yet whether models that include weather and avian dynamics improve forecast accuracy remains unclear. Using a 15-year weekly time series of mosquito abundance, mosquito infection prevalence, and human cases, we developed four mechanistic model configurations of varying complexity, from mosquito-human dynamics alone to full models incorporating avian dynamics and weather forcing. We fitted each model to the weekly-observed data, generated probabilistic 1- and 2-week-ahead forecast horizons, and evaluated forecasts against a historical baseline. All configurations fit the data equally regardless of weather or avian dynamics. However, models incorporating both birds and weather created more accurate forecasts of mosquito abundance and mosquito infection prevalence, and all configurations outperformed the baseline for forecasting human cases. Forecast accuracy was highest in summer and fall, and ensemble aggregation sometimes outperformed every individual model, stabilizing predictions across the 15-year record. These findings indicate that avian and weather dynamics are most critical for predicting mosquito-specific data, positioning this framework as a scalable tool for public health planning for WNV surveillance under climate change.

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Understanding urgent blood-donor mobilisability: a cross-sectional online survey of digitally reachable adults in Ghana

Shen, H.; Agorinya, I. A.; Ayanore, M. A.; Brede, M.; Chapman, A.; Head, M.

2026-08-31 public and global health 10.64898/2026.08.27.26361538 medRxiv
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Introduction Safe and timely blood availability remains a major global health challenge, especially in low- and middle-income countries. Digital tools may accelerate donor contact, but digital reachability alone does not ensure that people will notice, trust and act on urgent requests to support blood donation efforts. We examined factors associated with anticipated engagement in digitally coordinated urgent blood-donor mobilisation among digitally reachable adults in Ghana. Methods We conducted a cross-sectional online survey from September 2025 to January 2026 across Ghana's 16 regions. Participants were recruited via Facebook advertising and snowball sampling. Factors associated with urgent blood-donor mobilisability were assessed under four criteria: high future-donation willingness; high willingness to install a trusted donation app; high willingness to respond to a trusted urgent-request; and high practical flexibility to leave current activities. Descriptive analyses and multivariable logistic regression examined prevalence and associated factors. Results Among 1,067 participants, 577 (54.1%) met all four criteria. Future-donation willingness (91.8%), trusted-app installation willingness (83.2%) and trusted-request response willingness (82.7%) were common, whereas practical flexibility was lower (66.6%). In the adjusted model, high formal health-system trust (adjusted OR (AOR) 3.95, 95% CI 2.08-7.50), high digital-response readiness (AOR 2.26, 1.66-3.08), previous donation (AOR 1.47, 1.08-2.01), high donation knowledge (AOR 1.42, 1.03-1.97) and willingness to donate to strangers were positively associated with high mobilisability. Women (AOR 0.60, 0.43-0.83), participants reporting a work-schedule barrier (AOR 0.43, 0.29-0.66) and those travelling over 30 min to the nearest healthcare facility at night (AOR 0.66, 0.45-0.96) had lower adjusted odds. Conclusions Digital reachability and stated donation willingness may overestimate the population pool available for emergency donation. Digital blood-donor solutions should consider verifiable health-system requests, account for response readiness and current availability, and connect willing individuals with accessible collection options and transport support where needed.

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Identification of genetic variants in Pfs25 and functional evaluation in mosquito infection

Orfano, A.; Cisse, A.; Guo, Y.; Han, L.; Fikadu, N.; Thiam, L. G.; Ba, A.; Li, R.; Pouye, M. N.; Mangou, K.; Moore, A. J.; Sene, S. D.; Diallo, F.; Ngom, E. M.; Sadio, B.; Mbengue, A.; Membi, C.; Ngasala, B.; Bazie, T.; Some, F. A.; Olson, N.; Patel, S. D.; Shapiro, L.; Parikh, S.; Foy, B. D.; Cappello, M.; Vigan-Womas, I.; Premji, Z.; Dabire, R. K.; Ouedraogo, J.-B.; Sheng, Z.; Bei, A. K.

2026-08-31 infectious diseases 10.64898/2026.08.25.26361130 medRxiv
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Transmission-blocking vaccines (TBVs) are a promising strategy to reduce malaria transmission by targeting parasite stages within the mosquito. However, parasite genetic diversity may limit vaccine efficacy. We used next-generation amplicon deep sequencing to identify non-synonymous single nucleotide polymorphisms (SNPs) in Pfs25 from 184 Plasmodium falciparum isolates from Senegal, Tanzania, Ghana, and Burkina Faso. Prioritized SNPs were introduced into P. falciparum via CRISPR-Cas9. For the G116C variant, gametocyte development was evaluated by microscopy and qPCR, and mosquito infectivity was assessed by SMFAs. We identified 26 SNPs, including 24 novel variants. Functional assays showed that the Pfs25 G116C mutation did not affect gametocyte development or exflagellation. SMFA showed no significant differences in oocyst prevalence or intensity between mutant and WT parasites. These findings highlight the importance of integrating genetic surveillance with functional validation to guide the development of effective transmission blocking interventions

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Impact of Detection-Isolation-Leakage on the 2026 DRC Bundibugyo Ebolavirus Outbreak

Oraby, T.; Falay, D.; Ndeffo-Mbah, M. L.

2026-08-31 public and global health 10.64898/2026.08.25.26361360 medRxiv
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The 17th Ebola outbreak in the Democratic Republic of the Congo, announced on 15 May 2026, was attributed to Bundibugyo ebolavirus (BDBV). Although case isolation is the main control strategy, its effectiveness is compromised when patients escape isolation facilities before recovery. Between 14 May and 17 June 2026, 175 individuals reportedly left isolation facilities without formal discharge across Ituri Province. We assessed how this "isolation leakage" affects community transmission. We refined the SEIHFR framework to distinguish undetected community infections, detected but not-yet-isolated cases, isolated individuals, leakage, funeral-associated transmission, and removals. Using Bayesian inference, we fitted the model to daily Ituri surveillance data, escapee counts, and isolation census records. We estimated the leakage rate, reporting and detection probabilities, and the transmission rate, while fixing other parameters based on the BDBV literature. The model reproduced confirmed cases, deaths, discharges, and escapees. We estimated R_0=3.67 (95% HDI: 2.0-5.7), a leakage rate of {rho} {approx} 0.034 day^-1 (0.022-0.051), and high contact-tracing-driven detection (p_d {approx} 0.91-0.99). Leakage increased the detection-dependent reproduction number [R](p_d) from approximately 3.2 to above 5. Eliminating leakage reduced cumulative infections by about one-third, from 1,120 to 764, while the minimum detection level required for control increased from p_d [&ge;] 0.73 without leakage to p_d [&ge;] 0.87 at the fitted leakage rate. Shortening time to isolation prevented the most infections (73.4%; 59-84), followed by reducing leakage (29.7%; 14-52) and re-isolating escapees (12.6%; 6-24). Delaying leakage reduction until week 4 reduced its benefit from about 27% to below 2%. Isolation leakage represents a major transmission pathway that has until now gone largely unmeasured. While rapid initiation of isolation is highly beneficial, it cannot compensate for permeable isolation; therefore, early, community-driven efforts to control leakage, embedded within a multilayered response, are critical.

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Diversifying deaths: the shifting spectrum of childhood respiratory infectious mortality, 1990-2023: a systematic analysis of the Global Burden of Disease Study 2023

Li, D.; Chen, H.; Miao, Y.; Zhang, Y.; Wang, X.; Shen, C.

2026-09-03 epidemiology 10.64898/2026.09.01.26361937 medRxiv
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Background Childhood respiratory infectious deaths are partitioned across four Global Burden of Disease cause modules-26 etiological attributions within lower respiratory infections, tuberculosis, COVID-19, and whooping cough-never jointly reported. Whether the structure of this combined mortality spectrum has changed over time, and with what implications for intervention design, has not been quantified. We assembled and analyzed the integrated spectrum for children and adolescents aged 0-19 years, 1990-2023. Methods We integrated Global Burden of Disease Study 2023 (release v8352) estimates into a 29-node spectrum-26 lower respiratory infection etiologies plus tuberculosis, COVID-19, and pertussis-globally and across seven super-regions, with uncertainty propagated by summing bounds. We computed Shannon diversity, Herfindahl concentration, and effective cause counts; phenotyped pandemic-window collapse and rebound per cause; linked pathogen shares to WHO/UNICEF vaccine coverage; and mapped geographic concentration in sub-Saharan Africa and South Asia. Reporting follows GATHER. Results In 2023 the 29 causes jointly accounted for 965,330 deaths (95% uncertainty interval [UI] 680,096-1,342,437). Shannon diversity rose from 2.336 to 2.711 (+16.1%) between 1990 and 2023; the effective number of causes nearly doubled (5.57 to 9.94), inversely coupled to total deaths (Spearman rho = -0.997). Whooping cough ranked second (112,954 deaths; 95% UI 64,576-185,708; 11.7%) and showed the spectrum's only rebound above 100% (-57.4% collapse, +111.0% rebound). Tuberculosis ranked third (87,764; 57,779-124,912; 9.1%) with the highest concentration in sub-Saharan Africa and South Asia (87.1%). COVID-19 entered at rank five (52,899; 47,275-59,183; 5.5%). Nineteen of 29 causes exceeded the poverty-lock threshold (>80.59% of deaths in sub-Saharan Africa plus South Asia). Conclusions Childhood respiratory infectious mortality has become more diverse and more concentrated in poverty as it has declined. Single-pathogen interventions now address a shrinking share; the spectrum's structure argues for platform interventions-oxygen, antimicrobial access, referral-tailored jointly by age and geography, implying that pathogen-specific strategies alone cannot finish the remaining mortality agenda.

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No convergence in three decades: national trajectories of episode-fatality ratios for childhood lower respiratory infections in 204 countries, 1990-2023

Li, D.; Feng, Q.; Chen, H.; Li, J.; Wang, X.; Shen, C.

2026-09-03 epidemiology 10.64898/2026.09.01.26361942 medRxiv
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Background Lower respiratory infections (LRI) remain the leading infectious cause of death in children, and survival once ill is a direct tracer of health-system quality. Whether countries are converging toward the best survival performance achieved within their own region has never been tested at national level. We measured each country's distance to an empirical episode-fatality-ratio (EFR) frontier in 204 countries from 1990 to 2023. Methods For each country and year we computed EFR = LRI deaths/incident episodes using Global Burden of Disease (GBD) 2023 estimates for ages 0-19 years. Deaths span the full 1990-2023 series; episodes are observed for 1990, 2019 and 2023, with intermediate years linearly interpolated. The frontier was the 10th-percentile country EFR within each GBD super-region and year (sensitivity: 5th and 25th percentiles); the gap = EFR_country/EFR_frontier. We classified 33-year gap trajectories into catch-up phenotypes, ranked COVID-window (2019-2023) movers, cross-tabulated gap against avoidable deaths to build a priority list, and benchmarked upper respiratory infections (URI) at three time points as a near-zero-fatality contrast. Findings The median country's gap was 1.86 in 1990, 1.80 in 2019 and 1.86 in 2023; the share of countries more than twice their regional frontier was 44.6% in 1990 and 46.6% in 2023. Of 137 eligible countries, 67 narrowed and 69 widened their gap, with one unchanged. Nineteen countries achieved sustained catch-up, concentrated in North Africa and the Middle East (7) and Latin America (5), with China closing from 2.43 to 0.50, below its regional frontier; 28 countries regressed, led by Central Asia (Uzbekistan x3.5) and including the United States (x2.0). Over the COVID-19 window the median gap peaked at 2.00 in 2021 (+10.8% versus 2019, from unrounded medians) before returning to 1.86. Combining gap with avoidable deaths identifies two distinct policy problems: high-burden, moderate-gap giants (Nigeria 67,490 avoidable deaths, gap 2.4; India 54,109, gap 1.6) and extreme-gap outliers (Uzbekistan, gap 28.6). The Sub-Saharan Africa frontier fell further behind the High-income frontier (ratio 4.2 in 1990, 9.5 in 2023); the median Sub-Saharan African country sits 11.0 times the global 10th-percentile frontier but only 1.78 times its own regional frontier, so within-region benchmarking understates the region's true distance. URI gaps likewise did not converge (median 4.15 to 4.60). Interpretation Convergence toward the survival frontier is not the default national trajectory: over three decades the typical country made no net progress toward the best decile of its own region, and pandemic-era divergence was only partly reversed. National gap trajectories separate system-wide quality shortfalls from extreme outliers warranting audit, and expose a measurement trap in which regions whose frontiers stagnate appear closer to best practice than they are.

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Avoidable childhood respiratory-infection deaths: a frontier analysis of episode-fatality ratios in 204 countries, 1990-2023

Li, D.; Xie, J.; Xue, J.; Chen, H.; Wang, X.; Shen, C.

2026-09-03 pediatrics 10.64898/2026.09.01.26361882 medRxiv
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Background Respiratory infections remain the leading infectious cause of death among children and adolescents, yet the share of these deaths that could be averted with currently feasible care is not routinely quantified. Existing amenable-mortality frameworks rely on cause lists and population-level mortality benchmarks and do not exploit information on how many episodes occur. We propose an episode-fatality-ratio (EFR) frontier approach and apply it to lower respiratory infections (LRI), whooping cough (pertussis) and upper respiratory infections (URI) in 204 countries, 1990-2023. Methods For each cause, country and year we computed EFR = deaths/incident episodes using Global Burden of Disease (GBD) 2023 estimates for ages 0-19 years. The frontier was defined as the 10th-percentile country EFR within each GBD super-region, cause and year; avoidable deaths = max(0, deaths - episodes x frontier EFR). Primary estimates are deterministic; 95% uncertainty intervals (UIs) come from 2,000 Monte Carlo draws. Sensitivity analyses varied the frontier percentile, applied an aspirational global frontier, constructed pertussis counterfactuals, and recomputed all estimates within the single under-5 age band. Results In 2023, 333,803 childhood deaths from lower respiratory infections (95% UI 289,123-417,460; 46.9% of LRI deaths) were avoidable. Summing the three causes deterministically gives 391,034 avoidable deaths (46.5% of 840,444); the combined figure is a deterministic sum, and a UI is available for the LRI component only. The pertussis (43,958; 39.0%) and URI (13,273; 81.0%) estimates are secondary: their deterministic point values fall below their own Monte Carlo intervals and the underlying death estimates carry very wide uncertainty (global pertussis UI 12,545-321,874). Avoidable deaths fell from 1,050,468 (44.9%) in 1990, but between 2019 and 2023 the avoidable share for LRI+URI barely moved (48.7% to 47.7%) while absolute avoidable deaths fell 14.5%, a pattern consistent with stalled convergence to the frontier. Sub-Saharan Africa plus South Asia held 73.1% of avoidable deaths in 2023 versus 41.8% in 1990; ten countries accounted for 59.1%. Conclusion Nearly half of childhood respiratory-infection deaths remain avoidable relative to within-region best practice, and the residual burden is increasingly concentrated in low-income settings. In the pertussis counterfactual, most countries kept pace with their regional frontier, so further gains require advancing the frontier itself through quality-of-care improvements.

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Post-Discharge Experiences of Survivors Following the 2022 Ebola Virus Disease Outbreak in Uganda: An Exploratory Qualitative Study

Natukunda, J.; Muwanguzi, P.; Ngabirano, T. D.; Atuhaire, B.; Nalubega, S. J.; Auma, C.; Nabunya, R.

2026-09-03 public and global health 10.64898/2026.08.29.26361698 medRxiv
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Background: Ebola virus disease is a life-threatening illness caused by the Ebolavirus, with symptoms manifesting two to twenty-one days after infection. Although Uganda has faced multiple Ebola outbreaks, many patients survive only to encounter persistent challenges. Therefore, this study explored the post-discharge experiences of survivors following the 2022 Ebola Virus Disease outbreak in Uganda. Methods: An exploratory qualitative study comprising of in-depth participant interviews was conducted at Mubende Regional Referral Hospital in central Uganda. Interviews were face-to-face and data were analyzed manually by inductive content analysis. Ten male and female participants were Ebola Virus Disease survivors in Mubende district who had lived in the community for at least six months post-discharge from the Ebola Treatment Unit. Results: Four themes emerged: (i) Psychosocial Burdens and Social Exclusion, (ii) Economic Hardship and Loss of Financial Stability, (iii) Chronic Physical and Health Burdens Post-Recovery and (iv) Rebuilding Lives: Psychological, Social, and Medical Pathways to Recovery. Survivors faced significant emotional burdens such as survivor guilt, grief, trauma from loss, and anxiety about transmission risks. They experienced social isolation, stigma, and discrimination, which often led to their exclusion from community activities. Financially, they struggled with debt and the loss of livelihoods, compounded by ongoing health issues. Additionally, survivors endured chronic physical complications, including pain and fatigue, which hindered their recovery. Despite these challenges, survivors sought psychological, social, and medical pathways to recovery, including confirmation of their recovery, support from family and organizations, and health maintenance practices. Supportive medical care and community assistance were crucial in their physical and emotional rehabilitation. Conclusion: Ebola Virus Disease survivors in Uganda face significant psychosocial, health, social, and economic challenges post-discharge. The findings highlight the critical need for comprehensive medical and community-based support systems to aid survivors' recovery and well-being. Further research on long-term neurological effects and community reintegration programmes is needed to inform targeted interventions that support Ebola survivors and reduce stigma and discrimination.

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Types, Subtypes and Positivity Rates of Seasonal Influenza in Uganda, 2019-2023

Nankya, M. A.; Owor, N.; Kayiwa, J. T.; Lutwama, J. J.; Gidudu, S.; Bahizi, G.; Ario, A. R.

2026-09-01 infectious diseases 10.64898/2026.08.29.26361662 medRxiv
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Background: Seasonal influenza, commonly known as flu, is an acute respiratory, highly contagious illness caused by influenza viruses. A clear understanding of influenza seasonality is crucial for guiding prevention and treatment strategies, including decisions on vaccination timing to prevent outbreaks. While well documented in temperate regions, data on influenza epidemiology in tropical areas, particularly sub-Saharan Africa, remain limited. We described the types, subtypes and positivity rate of seasonal influenza in Uganda during 2019-2023. Methods: We abstracted data from the National Influenza database on positive seasonal influenza cases confirmed by Polymerase Chain Reaction. The cases were disaggregated by age group, sex, region, month and year of reporting. Using Microsoft excel, we calculated the influenza positivity rate and disaggregated it by strain, sex, age, region and time. Test positivity rate was computed as the number of positive cases as a percentage of the total samples tested. Results: Among 17,957 individuals tested, the overall positivity rate for seasonal influenza was 5% (936 cases). Positivity was higher among males compared to females (7% vs. 4%), with children aged 5-9 years having the highest positivity rate (16%), while individuals aged 50-54 years had the lowest (1%). The median positivity rate was 4%, with a range of 1-16%. Regionally, the central region reported a positivity rate of 5%, with rates across all regions ranging from 5% to 8%. Over time, there was a gradual decline in positivity rates, decreasing from 16.5% in 2019 to 5.3% in 2023. Seasonal influenza exhibited bimodal peaks, with the primary peak occurring between March and May and a secondary peak from October to December. Influenza A was the predominant strain, accounting for 70% of seasonal influenza cases (669/936). Among the Influenza A subtypes, H3N2 was most common, representing 63% of cases (425/669). Conclusions: The declining seasonal influenza positivity rates from 2019 to 2023 and the predominance of Influenza A and H3N2 highlight the need for sustained surveillance in Uganda. Given Influenza A's high genetic variability and potential for novel strain emergence, monitoring circulating strains, informing vaccine development, and implementing targeted interventions for high-risk groups and regions are critical to controlling and preventing outbreaks.