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Parasites & Vectors

Springer Science and Business Media LLC

Preprints posted in the last 7 days, ranked by how well they match Parasites & Vectors's content profile, based on 57 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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The epidemiological scenario of leptospirosis in Brazil from 2015 to 2024: An ecological study of socio-environmental and climatic determinants.

Fernandes, G. S. C.; Azevedo, B. O. P.; Damiano, D. K.; Lima, M. V. R.; Macena, P. d. P.; Teixeira, A. F.; Barazzone, G. C.; Nascimento, A. L. T. O.; Lopes, A. P. Y.

2026-04-17 epidemiology 10.64898/2026.04.15.26350927 medRxiv
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Background: Leptospirosis is a neglected tropical disease with substantial public health impact in Brazil, closely associated with socio-environmental vulnerabilities and climatic extremes. This study analyzed the epidemiological profile, spatiotemporal distribution, and climatic influences on leptospirosis incidence and lethality in Brazil from 2015 to 2024. Methods: An ecological time-series study was conducted using secondary data from the Notifiable Diseases Information System (SINAN). Variables included geographic region, probable infection environment, occupational, and educational level (ISCED-2011). The spatiotemporal correlation between disease incidence and El Nino-Southern Oscillation (ENSO) anomalies was assessed using the Oceanic Nino Index (ONI) and Spearman's rank correlation coefficient. Results: A total of 31,397 cases were notified, with an annual average of 3,140 cases. The South and North regions exhibited the highest incidence rates, while the Northeast and Southeast presented lethality rates above the national average (9.20%). A marked reduction in notifications occurred during the COVID-19 pandemic. Contaminations occurred predominantly in the domiciliary environment (64%). Rural workers (27.45%) and civil construction workers (18.63%) were the most affected occupational groups, with a higher incidence among illiterate and low-education populations. Climatic analysis revealed a positive spatial correlation between El Nino intensification and leptospirosis incidence in the South and Southeast, and a negative correlation in specific Northeastern states. Conclusion: The dynamics of leptospirosis in Brazil are complex and multifactorial, strongly influenced by macroclimatic variations and driven by deficits in basic sanitation and urbanization. Mitigating the disease burden requires sustained, region-specific public health strategies, targeted infrastructure improvements, and enhanced epidemiological surveillance to address underreporting.

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From district to community: fine-scale data and revised WHO guidance expand schistosomiasis treatment needs in Ethiopia and Zimbabwe

Carlin, A.; Fantaguzzi, C.; Seife, F.; Leta, G. T.; Phiri, I.; Dhanani, N.; Midzi, N.; Fleming, F. M.

2026-04-11 public and global health 10.64898/2026.04.07.26350372 medRxiv
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BackgroundSchistosomiasis remains a major public health challenge in sub-Saharan Africa. Recent World Health Organization (WHO) guidance calls for community-wide treatment and fine-scale data to optimise preventive chemotherapy (PC) strategies, yet the practical implications for resource allocation by health ministries are unclear. MethodsWe analysed epidemiological and cost data from Ethiopia and Zimbabwe to compare survey designs and five implementation scenarios. Scenarios varied by data source, administrative unit of implementation, WHO guidance on PC strategies. Outcomes were target population, praziquantel needs, and delivery costs. ResultsGeostatistical surveys reduced sample size by up to 90% and survey costs by [≥]72% compared with a design-based approach, while increasing spatial coverage. Applying updated WHO guidance expanded eligibility to pre-school-aged children and adults, and in one scenario increased treatment needs by 72% in Ethiopia and 262% in Zimbabwe. Correspondingly, praziquantel requirements and delivery costs were driven primarily by expanded age eligibility rather than geographic coverage. ConclusionsGeostatistical surveys provide substantial efficiency gains for impact assessments, enabling cost-efficient, granular targeting. However, implementing 2022 WHO guidance was the dominant driver of increases in programme scope and resource needs, underscoring the importance of accurate fine-scale data to guide efficient planning and budgeting toward elimination goals. Author summarySchistosomiasis control programmes are required to use finer-scale data and updated World Health Organization (WHO) guidance to decide where and how often to deliver praziquantel. We analysed national schistosomiasis data and programme costs from Ethiopia and Zimbabwe to compare different approaches to impact assessment surveys and to estimate how treatment needs change under alternative decision rules.We found that model-based geostatistical surveys can reduce the number of people that need to be sampled and the cost of surveys while providing more detailed information for planning at sub-district level. However, when we applied the 2022 WHO schistosomiasis guidance, expanded eligibility (including adults and pre-school-age children and a lower threshold for community-wide treatment) substantially increased the number of people needing treatment. In our scenarios, expanded eligibility drove much larger increases in praziquantel requirements and delivery costs than changes in geographic coverage. Our findings help health ministries to anticipate the operational and budget implications of updated guidance and highlight why accurate fine-scale data are essential for equitable and realistic planning toward elimination.

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Modelling serological cross-reactivity to disentangle the dynamics of West Nile and Usutu viruses in an emerging area

Bastard, J.; Migne, C.; Helle, T.; Agneray, E.; Bigeard, C.; Boudjadi, Y.; Chevrier, M.; Dumarest, M.; Gondard, M.; Martin-Latil, S.; Mathews-Martin, L.; Petit, T.; Charpentier, T.; Pouillevet, H.; Durand, B.; Metras, R.; Gonzalez, G.

2026-04-17 epidemiology 10.64898/2026.04.07.26350295 medRxiv
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Zoos may serve as sentinel sites for zoonotic vector-borne diseases. West Nile virus (WNV) and Usutu virus (USUV) are closely related orthoflaviviruses transmitted between Culex mosquitoes and a bird reservoir. Both viruses can also infect mammals, including humans, where they may cause symptoms and, more rarely, hospitalization and death. However, serological cross-reactivity between WNV and USUV complicates their differential diagnosis. Here, we aimed to reconstruct the dynamics of emergence of WNV in a zoo located in a newly affected area in Europe, using ELISA and Virus Neutralization Test (VNT) serological analysis of 1707 animal sera collected between 2015 and 2024. Combining this data in a model accounting for cross-reactivity with USUV, we estimated yearly forces of infection (FOI) by both viruses, and thus found that WNV likely circulated in the area one year prior to the first cases reported to the passive surveillance system. Our results also showed that, in the zoo, mammals and reptiles had a lower risk of infection than birds (relative risk of 0.14 [0.05; 0.28]), and that the exposure of birds to water (aquatic lifestyle or proximity to stagnant water) affected the risk. Finally, we estimated diagnosis parameters, including the sensitivity of the VNT (80.4% [76.5%; 84.3%]), the expected VNT titer value, and the level of serological cross-reactivity between viruses during the VNT. To conclude, our modelling framework allowed to disentangle the co-circulation of two closely related viruses, a crucial point in ensuring the reliable sentinel surveillance of these vector-borne zoonotic pathogens.

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Dengue risk perception and public preferences for vector control in Italy and France: utility and regret-based choice experiments

Andrei, F.; Tizzoni, M.; Veltri, G. A.

2026-04-11 epidemiology 10.64898/2026.04.10.26350604 medRxiv
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Background: Dengue is rapidly emerging in parts of Europe. How households value vector control attributes, and whether inferences depend on decision models or message framing, is unclear. Methods: We conducted a split-ballot online experiment among adults in Italy and France, as well as a hotspot subsample from Marche, Italy. National samples included 1,505 respondents in Italy and 1,501 in France; 183 respondents were recruited in Marche. Participants were randomised to a discrete choice experiment (random utility maximisation) or a regret-based choice experiment (random regret minimisation) and to one of three pre-task messages (control, loss aversion, community values). Each respondent completed 12 choice tasks comparing two dengue control programmes and an opt-out. We estimated mixed logit and mixed random-regret models with random parameters and treatment effects. Results: Across frameworks, nearby cases and high mosquito prevalence were the dominant drivers of programme uptake, whereas cost and operational burden were secondary. In pooled analyses, loss-aversion messaging increased the weight on high mosquito prevalence in both models (from 0.483 to 0.547 in the utility model; from 0.478 to 0.557 in the regret model). Cost effects were small nationally but larger in the hotspot subsample. Conclusions: Risk salience dominates preferences for dengue vector control in these European settings. Random utility and random regret models yield consistent rankings of attributes but differ in behavioural interpretation and some secondary effects; messaging effects were modest and context dependent.

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Chronic skin ulcers, Burkina Faso: review of consultation trends and patient types treated between 2013 and 2023 in the dermatology departments of Souro Sanou and Yalgado Ouedraogo University Hospitals

Christiana, K. A.; Anselme, M.; Juliette, T.-D.; Aristote Wendpanga, D. N.; Boukary, D.; Issouf, K.; Samuel, K. D.; Lydie, T. Y.; Madi, K.; Abdoulaye, O.; Madi, S.; Sanata, B.; Jacques, Z.; Therese, K.; Abdoul-Salam, O.; Baptiste, A. J.; Macaire, O.; Pascal, N.

2026-04-11 dermatology 10.64898/2026.04.07.26350370 medRxiv
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Social stigma surrounding chronic skin Ulcer leads patients to hide their wounds or delay seeking medical care. The aim of this study was to explore the types and causes of chronic skin ulcers among patients seen in the dermatology departments of two university hospitals in Burkina Faso. This was a cross-sectional, retrospective study covering an 11-year period, from 2013 to 2023. A review of consultation records allowed for the collection of sociodemographic and clinical data from 104 patients who were seen for chronic skin ulcers over the 11-year period, averaging 9 patients per year. The patients were primarily adults (n=60) and older adults (n=21). Leg ulcers were the condition observed in most patients (n=59). Eight cases of Buruli ulcer (7.69%) were identified among the 104 patients. Five of the eight cases, or 62.50%, were aged between 0 and 19 years. Half of the eight patients resided in Ouagadougou. These results highlight low utilization of dermatology services for chronic skin ulcers. Furthermore, indigenous cases of Buruli ulcer have been identified in Burkina Faso. Consequently, our findings call for the implementation of strategies focused on addressing social perceptions of these ulcers and on the screening and management of this disease.

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Bayesian spatial analysis of Plasmodium parasites prevalence and its determinants in selected regions of Mainland Tanzania

Challe, D. P.; Petro, D. A.; Francis, F.; Seth, M. D.; Madebe, R. A.; Kisambale, A. J.; Pereus, D.; Mandai, S. S.; Bakari, C.; Semboja, H. J.; Mwakasungula, S.; Chacha, G. A.; Budodo, R.; Mbwambo, D.; Aaron, S.; Lusasi, A.; Lazaro, S.; Mandara, C. I.; Makene, V. W.; Ishengoma, D. S.

2026-04-17 infectious diseases 10.64898/2026.04.13.26350696 medRxiv
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Background Malaria remains a major public health challenge globally and in Tanzania, driven by persistent Plasmodium parasite transmission, environmental variability, and socio-economic inequalities. Despite targeted control strategies, transmission remains heterogeneous and under-captured by routine surveillance. This study utilised community cross-sectional surveys (CSS) data and spatial modelling to determine household-level risk estimates and identify micro-hotspots to guide more efficient, evidence-based malaria interventions in Mainland Tanzania. Methods The CSS data used in this study were collected in 13 villages across five regions with moderate to high malaria transmission in Mainland Tanzania between July and August 2023. Individuals aged 6 months and above, residing in the study villages for 3 months and above, were enrolled after providing informed consent and tested for malaria using rapid diagnostic tests (RDTs). Socio-demographic, clinical, anthropometric, parasitological and geo-coordinates data were collected using structured electronic tools. Household-level Plasmodium parasite prevalence was modelled using Bayesian geostatistical methods implemented through Integrated Nested Laplace Approximation within a Stochastic Partial Differential Equation framework, incorporating relevant environmental covariates. Model performance was evaluated using the Watanabe-Akaike Information Criterion (WAIC). Results Bayesian models with village specific covariates consistently outperformed null models, as indicated by lower WAIC values. In Kyerwa district (Kagera region), grass cover increased the risk of Plasmodium parasite prevalence (Posterior mean (PM)=0.076; 95percent credible interval [CrI]: 0.040 -- 0.112), while altitude had a protective effect (PM = -0.002; 9percent CrI: -0.003 to -0.001), with strong sub-village clustering of malaria infection (variance=0.485; 95percent CrI [0.333 -- 0.730]). In Buhigwe district (Kigoma region), shrub cover increased the risk of Plasmodium parasite prevalence (PM=0.119; 95percent CrI: 0.029 -- 0.210) while in Ludewa (Njombe), both shrub (PM=0.512; 95% CrI: 0.066 -- 0.989) and grass (PM=0.490; 95percent CrI: 0.117 -- 0.879) increased the risk of infection, with pronounced sub-village clustering (variance=0.84; 95percent CrI: [0.38 -- 2.40] ). In Nyasa district (Ruvuma), shrub cover had a modest positive effect (PM=0.070; 95percent CrI: 0.005 -- 0.135), in Muheza district (Tanga region), its effect was influential (PM=0.160; 95percent CrI: 0.056 -- 0.266). Risk maps revealed fine scale heterogeneity in the household level risk of Plasmodium parasite prevalence. Conclusion There was pronounced micro-scale heterogeneity in Plasmodium transmission across the study districts, driven by localised environmental factors and strong spatial dependence. Altitude had a protective effect, while vegetation cover increased the risk of infection. Geostatistical models effectively identified household-level hotspots, highlighting the limitations of aggregated surveillance, emphasising the need for locally precision-guided malaria control strategies to improve intervention efficiency and enhance the ongoing elimination strategies.

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Assessing The Feasibility of AI-Driven Systems for Early Detection of Infectious Diseases at Julius Nyerere International Airport, Tanzania: Policy, Infrastructure, and Ethical Considerations

Malingumu, E. E.; Badaga, I.; Kisendi, D. D.; Pierre Kabore, R. W.; Yeremon, O. G.; Mohamed, M. A.; He, Q.

2026-04-13 public and global health 10.64898/2026.04.08.26350459 medRxiv
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This study evaluates the feasibility of implementing artificial intelligence (AI)-driven disease surveillance systems at Julius Nyerere International Airport (JNIA) in Tanzania, a key hub for regional and international travel. Through a mixed-methods approach combining qualitative interviews and quantitative surveys, the research assesses the infrastructure, human resource capacity, and regulatory frameworks necessary for AI integration. Findings indicate that while Port Health Officers are strongly optimistic about AIs potential to enhance disease detection, the airport faces significant barriers, including outdated infrastructure, insufficient technical resources, and a lack of trained personnel. Ethical and privacy concerns, particularly surrounding data security, also emerged as key challenges, compounded by limited public awareness and the socio-cultural acceptability of AI systems. Furthermore, the study identifies gaps in national policies and inter-agency coordination that hinder the effective implementation of AI technologies. The research concludes that while current conditions render AI adoption infeasible, strategic investments in infrastructure, workforce training, and policy development could pave the way for future integration, enhancing public health surveillance at JNIA and potentially other airports in low- and middle-income countries. This study contributes critical insights into the barriers and opportunities for AI-driven disease surveillance in low-resource settings, specifically focusing on a high-priority transit point, international airports. It emphasizes the importance of region-specific solutions to enhance health security in East Africa and supports the broader global health agenda by advocating for international collaboration and the development of scalable disease surveillance systems. Future research should explore pilot AI implementations at other airports to evaluate real-world challenges and refine AI systems for broader applicability, including cost-effectiveness analyses and integration of public perspectives on AI.

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Global determinants of vector-targeted insecticide use in public health: a modeling and mapping analysis

Heffernan, P. M.; van den Berg, H.; Yadav, R. S.; Murdock, C. C.; Rohr, J. R.

2026-04-13 public and global health 10.64898/2026.04.08.26350404 medRxiv
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BackgroundInsecticides remain the cornerstone of mosquito vector control for malaria, dengue, and other mosquito-borne diseases, yet global patterns of deployment and their socioeconomic and environmental drivers are poorly characterized. Understanding where and why insecticides are used is essential for better targeting control efforts and ensuring they are effective, equitable, and efficient. MethodsWe analyzed annual country-level insecticide-use data from 122 countries (1990-2019), reported as standard spray coverage for insecticide-treated nets (ITNs), residual spraying (RS), spatial spraying (SS), and larviciding (LA). Generalized linear mixed models and hurdle models quantified associations between deployment and disease incidence, human development index (HDI), human population density, temperature, and precipitation. Models were evaluated using repeated cross-validation and applied to generate downscaled predictions of insecticide use at subnational administrative region level 2 (ADM2) globally. FindingsInsecticide deployment increased with malaria and dengue incidence, but this response was substantially stronger in higher-HDI countries, indicating that deployment depends on socioeconomic capacity as well as disease burden that leads to weaker scaling in lower-resource settings. Intervention types exhibited distinct patterns; ITN use tracked malaria burden, whereas infrastructure-intensive approaches (e.g., RS and SS) were concentrated in higher-HDI settings and increased with Aedes-borne disease incidence. Downscaled ADM2-level maps uncovered substantial within-country heterogeneity that is obscured at the national scale, highlighting regions where predicted deployment remains low relative to disease risk across sub-Saharan Africa, South Asia, and parts of Latin America. InterpretationGlobal insecticide deployment reflects not only epidemiological need but also economic and logistical capacity, creating mismatches between risk and control. High-resolution mapping can support more equitable allocation of interventions, guide insecticide resistance stewardship, and improve strategic planning as climate and urbanization reshape mosquito-borne disease risk.

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Prevalence and Factors Associated with Family-Based HIV Index Case Testing in Wolaita Zone, Southern Ethiopia, 2023: A Cross-Sectional Study

Koyra, A. B.; Mohammed, F.; Eshete, T.

2026-04-11 epidemiology 10.64898/2026.04.08.26350444 medRxiv
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BackgroundFamily-based HIV index case testing identifies family members with unknown HIV status and links them to care. Data are limited in southern Ethiopia. MethodsA facility-based cross-sectional study was conducted among 377 adults on antiretroviral therapy (ART) in Wolaita Zone, Southern Ethiopia, from November 2022 to May 2023. Participants were selected using systematic random sampling. Data were collected via interviewer-administered semi-structured questionnaire. Multivariable logistic regression identified factors associated with index case family testing. Adjusted odds ratios (AOR) with 95% confidence intervals (CI) were calculated, and statistical significance was declared at p < 0.05. ResultsThe proportion of index case family testing for HIV was 84.9% (95% CI: 81.2- 88.6). In multivariable analysis, urban residence (AOR = 2.8; 95% CI: 1.16-6.75), duration on ART greater than 12 months (AOR = 13.0; 95% CI: 4.6-36.9), disclosure of HIV status to family members (AOR = 5.6; 95% CI: 1.9-16.5), discussion of HIV status with family members (AOR = 6.6; 95% CI: 1.9-23.2), and being counselled by health professionals to bring families for testing (AOR = 6.3; 95% CI: 2.1-19.0) were significantly associated with index case family testing. ConclusionThe prevalence of family-based HIV index case testing in Wolaita Zone was 84.9%, below the national 95% target. Health professionals should strengthen counselling on ART adherence, status disclosure, family discussion, and active referral to improve testing uptake among family members of people living with HIV.

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Bridging the Awareness Utilisation Gap in Reusable Menstrual Product Use Among Female Medical Students and Healthcare Professionals: A Cross-Sectional Study

Wami-Amadi, C. F.; Nonju, I. I.

2026-04-12 sexual and reproductive health 10.64898/2026.04.10.26350626 medRxiv
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Background: Reusable menstrual products provide sustainable and cost effective alternatives to disposable sanitary products; however, their adoption remains limited, even among healthcare professionals. Objectives: To assess awareness, knowledge, perceptions, and utilisation of reusable menstrual products among female medical students and healthcare professionals, and to identify predictors of willingness and use. Design: Cross sectional analytical study. Setting: An online survey was conducted among female medical students and healthcare professionals in Nigeria. Participants: A total of 203 female respondents aged 15 to 55 years. Intervention: Not applicable. Primary Outcome Measures: Utilisation of reusable menstrual products and willingness to adopt their use. Secondary Outcome Measures: Awareness, knowledge, perceptions, and barriers. Methods: Data were collected using a structured questionnaire and analysed using descriptive statistics, chi square tests, and logistic regression. Results: Awareness was high (96.06%), but utilisation was low, with 5.42% ever using and 4.43% currently using reusable products. About 31.53% were willing to use them. Respondent type was not associated with willingness (p = 0.735), although healthcare professionals had higher knowledge (p = 0.024). Positive perception predicted willingness (AOR = 7.58, 95% CI: 3.18 to 18.03, p < 0.001). Good knowledge (AOR = 14.96, p = 0.014) and increasing age (AOR = 1.28, p = 0.004) predicted utilisation. Conclusion: Despite high awareness, utilisation remains low. Perception influences willingness, while knowledge drives use. Targeted behavioural and educational interventions are needed. Keywords: Menstrual hygiene, reusable menstrual products, menstrual cup, sustainability, healthcare professionals

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Mediating Role of Depression and Anxiety in the Association Between Food Insecurity and Delayed TB Treatment in Botswana

Sakyi, E.; Molebatsi, K.; Modongo, C.; Shin, S. S.

2026-04-13 infectious diseases 10.64898/2026.04.08.26350465 medRxiv
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BackgroundDelayed tuberculosis (TB) treatment remains a major challenge to TB control and is associated with increased mortality, drug resistance, and onward transmission. Food insecurity may contribute to delayed TB treatment through economic, physical, and psychosocial pathways. Depression and anxiety are also associated with delayed TB treatment and may mediate the relationship between food insecurity and delayed TB treatment. This study examined the association between food insecurity and delayed TB treatment initiation and assessed the mediation roles of depression and anxiety for this relationship among people newly diagnosed with TB. MethodsWe recruited 180 participants newly diagnosed with TB in Gaborone, Botswana. Food insecurity, depression, and anxiety were measured using the Household Food Insecurity Access Scale, PHQ-9, and Zung Self-Rating Anxiety Scale, respectively. Delayed TB treatment was defined as > 2 months since first TB symptoms. Logistic regression was used to examine the association between food insecurity and delayed TB treatment. Causal mediation analysis was conducted to assess the mediating roles of depression and anxiety. ResultsAmong the 180 participants, 45 (25%) experienced delayed TB treatment initiation. Participants with delayed TB treatment had slightly higher median scores for food insecurity (2 vs. 1, p = 0.11), depression (9 vs. 6, p = 0.001), and anxiety (37 vs. 34, p = 0.05). There was insufficient evidence of an overall association between food insecurity and delayed TB treatment initiation (OR = 1.04, 95% CI 0.98-1.11, p = 0.20). Mediation analysis found insufficient evidence of total and direct effects through depression and anxiety. However, there was evidence of significant indirect effect through depression (OR = 1.04, 95% CI 1.01-1.08, p < 0.001) and a borderline indirect effect through anxiety (OR = 1.02, 95% CI 1.00-1.04, p = 0.05). ConclusionMediation analysis revealed associations between food insecurity and delayed TB treatment initiation mediated by depression and anxiety which were not evident in total effects analysis. These findings highlight the importance of considering both socioeconomic and psychological factors in addressing delayed TB treatment. Further studies are needed to confirm these pathways.

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Automated Detection of Dental Caries and Bone Loss on Periapical and Bitewing Radiographs using a YOLO Based Deep Learning Model

Alqaderi, H.; Kapadia, U.; Brahmbhatt, Y.; Papathanasiou, A.; Rodgers, D.; Arsenault, P.; Cardarelli, J.; Zavras, A.; Li, H.

2026-04-17 dentistry and oral medicine 10.64898/2026.04.12.26350726 medRxiv
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BackgroundDental caries and periodontal disease represent the most prevalent global oral health conditions, collectively affecting several billion people. The diagnostic interpretation of dental radiographs, a cornerstone of modern dentistry, is associated with considerable inter-observer variability. In routine clinical practice, clinicians are required to evaluate a high volume of radiographic images daily, a cognitively demanding task in which diagnostic fatigue, time constraints, and the inherent complexity of overlapping anatomical structures can lead to the inadvertent oversight of early-stage pathologies. Artificial intelligence (AI) offers a transformative opportunity to augment clinical decision-making by providing rapid, objective, and consistent radiographic analysis, thereby serving as a tireless adjunct capable of flagging findings that may be missed during routine human inspection. MethodsThis study developed and validated a deep learning system for the automated detection of dental caries and alveolar bone loss using a dataset of 1,063 periapical and bitewing radiographs. Two separate YOLOv8s object detection models were trained and evaluated using a rigorous 5-fold cross-validation methodology. To align with the clinical use-case of a screening tool where high sensitivity is paramount, a custom image-level evaluation criterion was employed: a true positive was recorded if any predicted bounding box had a Jaccard Index (IoU) > 0 with any ground truth annotation. Model performance was systematically evaluated at confidence thresholds of 0.10 and 0.05. ResultsAt a confidence threshold of 0.05, the caries detection model achieved a mean precision of 84.41% ({+/-}0.72%), recall of 85.97% ({+/-}4.72%), and an F1-score of 85.13% ({+/-}2.61%). The alveolar bone loss model demonstrated exceptionally high performance, with a mean precision of 95.47% ({+/-}0.94%), recall of 98.60% ({+/-}0.49%), and an F1-score of 97.00% ({+/-}0.46%). ConclusionThe YOLOv8-based models demonstrated high accuracy and high sensitivity for detecting dental caries and alveolar bone loss on periapical radiographs. The system shows significant potential as a reliable automated assistant for dental practitioners, helping to improve diagnostic consistency, reduce the risk of missed pathology, and ultimately enhance the standard of patient care.

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Thoracostomy Tube Infections: Prevalence and Associated Clinical Characteristics at a Tertiary Hospital in Northern Tanzania

Rwomurushaka, E. S.; Damas, L.; Niccodem, E.; Mwakyembe, T. E.; Msuya, D.; Chilonga, K.; Sango, M.

2026-04-17 surgery 10.64898/2026.04.15.26350981 medRxiv
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Background: Chest tube infection is one of the complications of the tube thoracostomy. Infectious complications may develop in 2% to 25% of patients who undergo thoracotomy tube placement. The use of prophylactic antibiotics to prevent infections associated with thoracostomy tubes remains a subject of debate. Current practices in managing infections related to tube thoracostomy are hindered by the lack of comprehensive and localised data on the microbial profile and their resistance patterns. Objective: To determine the prevalence of thoracostomy tube infections and associated clinical characteristics among patients treated with a thoracostomy tube at KCMC Zonal Referral Hospital. Methodology: Prospective cohort study done at KCMC Zonal Referral Hospital. Include all patients undergoing thoracostomy tube insertion from September 2024 to April 2025. Results: A total of 84 patients underwent tube thoracostomy during the study time. Of these 22 (26.2%) developed SSI. Out of the 22 samples collected, 17 (77.3%) had positive culture results. The most commonly identified pathogens were Pseudomonas aeruginosa (41.2%) and Staphylococcus aureus (29.4%). The highest overall susceptibility was observed with amikacin, effective against 10 (58.8%) of the tested organisms. The most common resistance was observed against ceftazidime (56.3%) and piperacillin-tazobactam (50.0%). Prolonged chest tube duration (>7 days) was the strongest independent predictor of tube thoracostomy infection. Conclusion: This study revealed a high prevalence of tube thoracostomy infection. Prolonged tube duration and admission to a non-surgical ward care emerge as key risk factors for SSI. These findings underscore the importance of limiting chest tube duration when clinically feasible and ensuring optimal postoperative care environments to minimise the risk of infection.

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Structural barriers to social protection and HIV prevention services for sex workers in Southeast Asia: a fixed-effects panel data analysis, 2018-2025

Hung, J.; Smith, A.

2026-04-16 health policy 10.64898/2026.04.12.26350700 medRxiv
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Introduction. Empirical evidence linking specific national structural policies to the provision of key HIV services in low- and middle-income settings remains scarce. This study addresses the research gap by quantifying the within-country relationships between six national structural policy indicators and the presence of the HIV prevention service component targeted at sex workers in Southeast Asia. Methods. We constructed a balanced panel dataset covering eight Southeast Asian countries from 2018 to 2025 from the UNAIDS Global AIDS Monitoring (GAM) framework. We used Fixed-Effects (FE) and Random-Effects (RE) models to analyse the relationships, with the FE model selected as the more statistically appropriate estimator. We enhanced robustness by using clustered standard errors and one-period lagged explanatory variables. Results. The primary finding from the FE model indicated a statistically significant and positive contemporaneous association between the existence of legal or administrative barriers to social protection (barriers_spi,t) and the presence of HIV prevention services for sex workers ({beta} = 0.8531; p < 0.001). However, the robustness check revealed a statistically significant negative association between the two when using the lagged barrier variable (barriers_spi,t-1), suggesting a decline in HIV prevention service availability over time ({beta} = -0.3540; p < 0.05). We did not find any other policy variable's coefficient to be statistically significant in the FE models. Conclusions. While the immediate recognition (contemporaneous effect) of structural barriers to access social protection may occur alongside prioritised HIV prevention service provision, the sustained presence of these impediments acts as a long-term constraint that undermines the effectiveness and sustainability of targeted HIV programmes. National HIV programmes must urgently prioritise the removal of structural barriers to ensure long-term service stability for key populations.

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Predictors of intention to use mobile health apps for comprehensive sexuality education among young people in the Democratic Republic of Congo: a correlational study

Maneraguha, F. K.; Cote, J.; Bourbonnais, A.; Arbour, C.; Chagnon, M.; Hatem, M.

2026-04-13 public and global health 10.64898/2026.04.09.26350561 medRxiv
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Background Comprehensive sexuality education (CSE) is essential to the health and well-being of young people. In the Democratic Republic of Congo (DRC), where more than 65% of the population is under the age of 25, access to interpersonal CSE remains limited owing to sociocultural and structural barriers. This exposes young people to persistent socio-sanitary vulnerabilities. In this context, mobile health apps (MHAs) constitute a promising solution, supported by the growing use of smartphones among young Congolese. However, this group's intention to use MHAs for CSE has been the subject of little research to date. Objective The aim of this study was to identify predictors of intention to use MHAs among young Congolese, based on the extended Unified Theory of Acceptance and Use of Technology (UTAUT2). Methods A predictive correlational study was conducted in eight public secondary schools in Bukavu (DRC) with a stratified random sample of 859 students. Predictors of intention to use--performance expectancy (PE), effort expectancy (EE), social influence (SI), facilitating conditions (FC), and perceived risk (PR)--and moderators--age, gender, and past MHA experience--were measured from data collected through a self-administered UTAUT questionnaire. Descriptive and multivariate analyses were run on SPSS version 28. Results Mean age of participants was 16.3 years (SD = 1.5). Boys made up 55.1% of the sample. Overall, 51.0% of the sample owned a smartphone, of which 62.3% reported having easy access to mobile data and 16.2% were already using MHAs to learn about sexual health. Intention to use MHAs was positively influenced by PE ({beta} = 0.523, p < 0.001), EE ({beta} = 0.115, p < 0.001), and SI ({beta} = 0.113, p < 0.001). FC (p = 0.260) and PR (p = 0.631), however, had no significant influence. Age moderated all of the relationships tested (F (1, 849-854) = 9.97-20.82; p [&le;] 0.002), with more marked effects observed among younger participants 14-15 years old. The final model explained 44% of the variance, indicating good predictive power. Conclusion Intention to use digital CSE was explained primarily by PE, EE, and SI and moderated by age. To strengthen this intention, stakeholders will need to promote e-interventions that are pertinent, easy to use, socially valorized, and tailored to young people's needs and to the local context.

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Prevalence and factors associated with reporting of sexual violence among secondary school adolescents in Ibadan Metropolis, Nigeria: A cross-sectional study

Olaniyan, H. O.; Olumide, A. O.

2026-04-11 public and global health 10.64898/2026.04.08.26344946 medRxiv
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BackgroundSexual violence (SV) is a major public health problem with far-reaching consequences; however, adolescent survivors rarely seek help. This underestimates the prevalence of SV and undermines prevention and response efforts. This study was conducted to determine the prevalence and reporting of sexual violence among adolescents in Ibadan, Nigeria. MethodsBetween September and October 2021, a cross-sectional study was conducted among 360 in-school adolescents in Ibadan South-West local government area, Nigeria. Adolescents were selected using multi-stage sampling. Information on experience and reporting of sexual violence was obtained with the aid of an interviewer-administered questionnaire. Data were analysed using descriptive and inferential statistics at p[&le;]0.05 level. ResultsRespondents mean age was 14.6{+/-}1.7 years, and 50% were female. Thirty-five per cent reported at least one incident within the past 12 months. Forms of sexual violence experienced included unwanted sexual touch (25.6%), forced sex (19.2%), attempted rape (15.2%), and suggestive comments (9.6%). Seventy per cent of adolescents who experienced sexual violence did not report to anyone; reasons included fear of getting in trouble (46.6%), thinking it was not a problem (31.8%), feeling it was their fault (30.7%), and embarrassment for self/family (27.3%). Adolescents who were closer to their mothers and younger adolescents were more likely to report their experience of sexual violence (p=0.006 and p=0.038, respectively). ConclusionSexual violence is common among in-school adolescents in Ibadan, yet reporting remains low. This study highlights the need to strengthen prevention and address barriers to reporting among adolescent survivors. Key MessageO_ST_ABSWhat is already known on this topicC_ST_ABSSexual violence has physical, psychological, and social consequences on the health and well-being of adolescent survivors, and low levels of reporting and help-seeking contribute to these consequences. What this study addsThis study provides evidence on the prevalence and reporting patterns of sexual violence among adolescents in Ibadan, Nigeria. It highlights key barriers and facilitators of reporting. How this study might affect research, practice, or policyThis study provides information about factors at individual, relationship, societal and policy levels that are associated with reporting and help-seeking among adolescent survivors of sexual violence in Ibadan, Nigeria. This highlights the importance of training stakeholders, such as parents, teachers, health workers, other caregivers and the adolescents themselves, on responding to sexual violence experience and reporting. It underscores the need for improved adolescent-friendly services, policy implementation and collaboration across families, schools, communities and states to address sexual violence.

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Adherence in Monitoring of ART response and turnaround time of results as per HIV viral load testing guideline among people living with HIV in Dar es salaam Region.

Masegese, T.; MUNG'ONG'O, G. S.; Kamala, B.; Anaeli, A.; Bago, M.; Mtoro, M. J.

2026-04-16 public and global health 10.64898/2026.04.14.26350908 medRxiv
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Background: HIV/AIDS remains a major public health challenge in Tanzania, where viral load suppression among adults on ART stands at 78% and HVL testing uptake among eligible patients is approximately 22%. Since the introduction of the National HVL Testing Guideline in 2015, little has been done to systematically evaluate its implementation. Objective: To evaluate adherence to the National HVL Testing Guideline across CTC clinics in Dar es Salaam Region, covering ART monitoring, documentation, turnaround time, and factors affecting implementation. Methods: A cross-sectional study was conducted in 2021 across 15 public health facilities with CTC clinics in all five Dar es Salaam districts. A total of 330 PLHIV on ART for more than six months were selected through systematic random sampling with proportional to size allocation, and 45 healthcare providers through convenient sampling. Data were collected via abstraction forms and self-administered questionnaires, and analysed using SPSS Version 23 with descriptive statistics, bivariate analysis, and binary logistic regression. Results: Only 25.1% of patients had their first HVL sample taken at six months as per guideline, with 68.8% delayed beyond six months. Second and third samples were similarly delayed. MoHCDGEC sample tracking forms were absent in 96.7% of facilities and incomplete in 99.1%, and no facility captured specimen acceptance or rejection as site feedback. Turnaround time exceeded the 14-day guideline threshold in 64.5%, 66.7%, and 69.4% of first, second, and third results respectively. Patient negligence (AOR=9.84; 95% CI: 1.83-52.77) and storage (AOR=5.72; 95% CI: 0.94-35.0) were independently associated with guideline adherence. Conclusion: Adherence to the National HVL Testing Guideline in Dar es Salaam is suboptimal across testing timelines, documentation, and turnaround time, with patient negligence and storage capacity as significant determinants. Targeted interventions are needed to strengthen patient education, improve storage infrastructure, enhance documentation systems, and support providers in adhering to guideline-specified timelines.

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Understanding community knowledge, attitudes and practices related to participation in household transmission investigations during infectious disease outbreaks

Meagher, N.; Hettiarachchi, D.; Hawkins, M. R.; Tavlian, S.; Spirkoska, V.; McVernon, J.; Carville, K. S.; Price, D. J.; Villanueva Cabezas, J. P.; Marcato, A. J.

2026-04-13 epidemiology 10.64898/2026.04.08.26350464 medRxiv
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BackgroundThe World Health Organization has developed several global template protocols for epidemiological investigations, including for household transmission investigations (HHTIs). These investigations facilitate rapid characterisation of novel or re-emerging respiratory pathogens and support evidence-based public health actions. Beyond technical readiness, community buy-in is central to the feasibility and acceptability of HHTIs. Research is needed to determine the perceived legitimacy among the community to inform local protocol adaptation and development of implementation plans that consider community attitudes and needs. MethodsIn 2025, we conducted a convenience survey of community members living in Victoria, Australia to explore: their understanding of emerging respiratory diseases; their willingness to take part in public health surveillance activities such as HHTIs; the acceptability of clinical and epidemiological data collection and respiratory/blood sample collection as main components of HHTIs, and; participant comfort towards including their companion animals in HHTIs. ResultsWe received 282 survey responses, of which 235 were included in the analysis dataset. Compared to the general Victorian population, our participants included a higher proportion of participants who reported being female, tertiary-educated, of Aboriginal and/or Torres Strait Islander heritage, born in Australia and speaking only English at home. Participants indicated overall high levels of comfort and acceptability towards participation in HHTIs, particularly in relation to clinical and epidemiological data collection, with lesser but still high levels of comfort with providing multiple respiratory specimens in a 14-day period. Participants were least comfortable with other specimens such as urine and blood. Involving companion animals in HHTIs was similarly acceptable as human-focused components. ConclusionsDespite our survey population being non-representative of the general Victorian population, our findings provide valuable descriptive insights into the acceptability of HHTIs in Victoria, Australia from which to benchmark future local and international surveys and community engagement activities.

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Gametocyte production and infectivity among Ugandan malaria patients infected with P. falciparum with partial resistance to artemisinins

Ayo, D.; Blanken, S. L.; Onyige, I.; Musasizi, E.; Proellochs, N.; Katairo, T.; Kiyaga, S.; Nsengimaana, B.; Wiringlimanna, I.; Semakumba, F. D.; Ssewanyana, I.; Lanke, K.; Opiyo, D.; Kamya, M. R.; Dondorp, A.; Briggs, J.; Etwop, T.; Greenhouse, B.; De Vries, L. E.; Etwop, T.; Huang, L.; Dorsey, G.; Drakeley, C.; Rosenthal, P. J.; Conrad, M. D.; Arinaitwe, E.; Okao, M.; Bousema, T.

2026-04-13 infectious diseases 10.64898/2026.04.09.26350477 medRxiv
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Background: Partial resistance to artemisinins (ART-R) has emerged in East Africa, associated with mutations in the Plasmodium falciparum kelch13 gene. It is currently unclear whether ART-R has implications for gametocyte production or for onward transmission to mosquitoes. Methods: In a cohort of uncomplicated malaria patients attending Kalongo Hospital in northern Uganda, we quantified carriage of PfKelch13 mutant parasites by conventional sequencing and droplet digital PCR (ddPCR) for the C469Y and A675V mutations. Prevalence and density of gametocytes and ring-stage parasites were assessed by microscopy and quantitative reverse-transcriptase PCR (qRT-PCR). Lumefantrine concentrations, indicative of prior malaria treatment, were determined by ultra-high performance liquid chromatography-tandem mass spectrometry. Transmission potential of wild-type and PfKelch13 mutant parasites was assessed by mosquito feeding assays and complemented with molecular characterization of parasites in wild-caught mosquitoes from household resting catches. Findings: We enrolled 235 patients with symptomatic P. falciparum infection; PfKelch13 C469Y or A675V mutations were detected in 35.8% (78/218) of infections by sequencing and 59.1% (136/230) by ddPCR. Gametocyte carriage was 24.0% (56/233) by microscopy and 56.6% (133/235) by qRT-PCR and not associated with the abundance of PfKelch13 mutant parasites by ddPCR (p=0.603). Among a total of 227 mosquito feeds with patient whole blood, 1.4% (120/8745) of mosquitoes became infected. Mosquito infection rates were positively associated with gametocyte density ({beta} = 0.39, 95% CI = 0.23-0.59, p < 0.001) without an observed interaction with the abundance of PfKelch13 mutant parasites (p = 0.452). PfKelch13 C469Y or A675V mutations were detected in 40.1% (21/52) of malaria-infected bloodmeals of field-caught mosquitoes and in 28.0% (7/25) of sporozoite-positive mosquitoes. Interpretation: We conclude that pfkelch13 mutations are very common in patients in northern Uganda with uncomplicated malaria, mostly in multiclonal infections. We observed no evidence that ART-R affected gametocyte production or transmission to mosquitoes. Funding: Dutch Research Council (NWO)

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Strengthening School Water, Sanitation and Hygiene (WASH) Programme Implementation: Evidence from Expert Consensus in Uasin Gishu County, Kenya

SERONEY, G. C.; Magak, N. A. G.; Mchunu, G. G.

2026-04-16 public and global health 10.64898/2026.04.14.26350916 medRxiv
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Introduction Access to safe water, sanitation, and hygiene (WASH) in schools is critical for child health, learning, and gender equity. In Kenya, the Kenya School Health Policy and the Basic Education Act outline standards for school WASH; however, implementation remains uneven due to inadequate infrastructure, weak inter-sectoral coordination, and limited financing. This study aimed to identify priority components for strengthening school WASH implementation and generate policy-relevant recommendations based on expert consensus in Uasin Gishu County, Kenya. Methods and Results A Delphi technique consisting of two iterative rounds was used to reach expert consensus. In Round 1, 20 purposively selected experts including head teachers, county education officials, public health officers, water and public works officers, and NGO representatives participated in key informant interviews. Emergent themes informed development of a structured Round 2 questionnaire administered through CommCare online app. Quantitative data were analyzed using descriptive statistics (means, standard deviations, percentage agreement), while qualitative responses underwent thematic coding using NVivo 12. Experts reached strong consensus on essential components required for strengthening school WASH implementation. Key priorities included clear governance structures, designated budget lines, inclusive infrastructure, menstrual hygiene management (MHM), curriculum integration, sustained capacity building, and systematic monitoring. Multi-sectoral collaboration and recognition of best-performing schools were also emphasized as important motivators for compliance and sustainability. Equity considerations particularly the need for disability-friendly facilities and school-community outreach were highlighted as critical. Agreement levels ranged from 74% to 100%, with most items scoring mean values between 4.5 and 4.8 on a 5-point Likert scale, indicating strong consensus among experts. Conclusion strengthening implementation of school WASH in Kenya requires coordinated governance, predictable funding, reliable water systems, inclusive sanitation, strengthened MHM, and consistent monitoring beyond infrastructure investment alone. Integrating these expert-validated priorities within existing national policies offers a practical pathway to improving learner health, reducing absenteeism especially among girls and promoting equitable educational outcomes.