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Epidemiology and Infection

Cambridge University Press (CUP)

Preprints posted in the last 7 days, ranked by how well they match Epidemiology and Infection's content profile, based on 84 papers previously published here. The average preprint has a 0.09% match score for this journal, so anything above that is already an above-average fit.

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Meningitis vaccination campaign in the context of COVID-19 in Cameroon

Mbang, M. A.; Cheuyem, F. Z. L.; Tchamani, R.; Debnet, J.; Ebongo, Z. N.; Fouda, A. A. B.

2026-06-04 public and global health 10.64898/2026.06.02.26354702 medRxiv
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Objective: The study aimed to describe the challenges, best practices, and lessons learned during meningitis vaccination campaigns conducted in the context of COVID-19 in Cameroon in 2020. Results: During the prevention campaigns, 3,460 individuals were selected. All were tested before the campaign (100%). Eight cases were positive, representing a positivity rate of 0.23% (8/3,460). The campaign was carried out using a fixed strategy in health facilities and prisons and a fixed-temporary strategy in communities. Most health areas received sufficient quantities of COVID-19 equipment for some items and insufficient quantities for others. No screening was done during or after the campaign. The main difficulties encountered were compliance with social distancing and the continuous wearing of gowns. The challenges faced were the screening of actors and the use of personal protective equipment. Lessons learned: aspects related to COVID-19 impacted the speed of the campaign. Vaccination coverage ranged from 91% to 140% in prisons on the one hand, and from 35% to 112% in the health areas surrounding prisons on the other. The campaign in the context of COVID-19 was effective. Compliance with barrier measures was not optimal due to difficulties encountered with aspects such as social distancing, continuous wearing of gowns, screening of participants during and after the campaign, and insufficient personal protective equipment.

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Investigation of the continuous spread of SARS-CoV-2 in the post pandemic time - Insights into the reason for the sustained spread despite the establishment of population immunity

Yi, B.

2026-06-08 epidemiology 10.64898/2026.06.05.26355009 medRxiv
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In spite of well-established global immune landscape, SARS-CoV-2 is still able to further spread and continue causing infection waves. The current understanding about the reason behind is limited, and it is still difficult to predict the evolution or spreading tread of SARS-CoV-2. Therefore, it is necessary to investigate whether the establishment of population immunity has changed the virus evolution or spreading pattern. In this investigation, one overall analysis of the SARS-CoV-2 spreading in the past several years have been carried out through one thorough genomic epidemiology study, with Germany being chosen as one representative location in view of the systemic efforts for genomic surveillance. The growth advantage of a few predominant variants in its early spreading period has been evaluated through a logistic regression model. The results have revealed that the major circulating SARS-CoV-2 variants since 2023 are mainly derived from the Omicron BA.2 family. Since middle of 2024, most predominant variants were produced primarily through recombination, indicating that the evolution derived from recombination might be the major driving force for the continuous spread of SARS-CoV-2 despite the existence of population immunity. Furthermore, the lower growth advantage of recently emerged variants might possibly lead to a tread of reduction in the frequency of infection wave. The information revealed from this investigation suggests that although short-term spreading tread can be affected by specific virus feature as well as local immunity landscape, the long-term spreading tread is mainly decided by the genomic diversity of the viruses, and can be predicted through phylogenetic and genomic epidemiology investigation. The results have emphasized the importance of maintaining the efforts for genomic surveillance of SARS-CoV-2, which is essential from both medical and research perspectives.

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Exploring emergency department attendance patterns during the UEFA European Football Championship 2024 in Germany

Charfeddine, N.; Schranz, M.; Schlump, C.; Rupprecht, M.; Ullrich, A.; Diercke, M.; AKTIN Research Group, ; Estupinan Mendez, J.

2026-06-09 epidemiology 10.64898/2026.06.08.26355151 medRxiv
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Background: Mass gathering events (MGEs) are associated with several public health challenges and may cause a strain on healthcare services. Literature findings on the impact of MGEs on emergency departments (EDs) are heterogeneous. Objectives: To examine shifts in ED attendance characteristics during a major sporting tournament, namely the UEFA European Football Championship 2024 held in Germany. Methods: We conducted a retrospective observational study using ED data from the Emergency Department Data Registry. We compared baseline ED attendance characteristics between the tournament and the reference period, defined as two weeks before and two weeks after the tournament, and between Germany game days and non-Germany game days. Hourly attendance patterns were analysed for all Germany games using a reference range. Results: We included data from 41 EDs, totalling 253,493 attendances during the study period. A 1.57% increase in attendance was observed during the tournament compared to the reference period, with baseline characteristics remaining similar. The median daily attendance within all EDs was slightly lower on Germany game days (4066) compared to non-Germany game days (4128). Modest changes were observed in the hourly attendance on Germany game days, most notable during the last Germany game where a decrease in attendance below the reference range extended over three hours. Conclusions: The observed shifts in ED attendance were minimal, suggesting that no major changes of public health relevance occurred in ED attendance during the tournament. We highlight the utility of using ED data for monitoring and for enhancing the understanding of the public health risks and challenges associated with MGEs.

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Translation and Cross-cultural Validation of Leprosy Case Detection Delay Questionnaire Among Persons Affected by Leprosy in Southeast Nigeria

Eze, C. C.; Murphy-Okpala, N. N.; Ekeke, N.; Nwafor, C.; Egbule, D.; Njoku, M.; Ezeakile, O.; Meka, A.; Iyama, F. S.; Ogbuefi, E.; Ugwu, O.; Solomon, M.; Adesigbin, C.; Chukwu, J.

2026-06-09 public and global health 10.64898/2026.06.06.26355058 medRxiv
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Introduction Reducing delays in leprosy case detection is essential for achieving global leprosy targets. Accurate measurement of these delays and their determinants relies largely on patient-reported data, as routine health records are often inadequate. The leprosy case detection delay (CDD) questionnaire, developed under the Post Exposure Prophylaxis for Leprosy (PEP4LEP) project, has been validated in Ethiopia, Mozambique, Tanzania, and Indonesia. However, it has not been adapted or validated for Nigeria or any major Nigerian indigenous language. This study aimed to culturally adapt and validate the CDD questionnaire for Igbo-speaking populations in Nigeria. Methodology/Principal Findings The CDD questionnaire underwent a standardized cross-cultural adaptation process. Content validity was assessed using item- and scale-level content validity indices, while construct validity was evaluated through hypothesis testing. Reproducibility was assessed using test-retest and inter-rater reliability; agreement using the Bland-Altman method and the Wilcoxon Signed-Rank test; reliability using Spearmans rank correlation coefficient and the Intraclass Correlation Coefficient (ICC); and internal consistency using Cronbachs alpha. Data were collected through face-to-face interviews with persons affected by leprosy at two time points separated by at least two weeks. Participants (n=100) had a mean age of 45.1 years (SD=18.7). Mean CDD was 77.2 months at baseline and 77.9 months at retest. The instrument demonstrated excellent content validity (I-CVI/S-CVI: 0.90-1.00), good internal consistency (Cronbachs =0.77), and excellent test-retest reliability (ICC=0.996, 95% CI: 0.994-0.997). Test and retest measurements were highly correlated ({rho}=0.985, p<0.001), with no evidence of systematic change over time (p=0.864). Seventy-two percent of participants reported identical CDD values across assessments. All items from the original English version were retained without modification. Conclusion/Significance The Igbo version of the CDD questionnaire demonstrated good validity and reliability and is suitable for assessing leprosy case detection delay among Igbo-speaking populations in Nigeria

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Spatial and temporal associations between animal ownership and malaria prevalence in Africa using cross-sectional national Demographic and Health Surveys

Topazian, H. M.; Morgan, C. E.; Goel, V.

2026-06-08 epidemiology 10.64898/2026.06.05.26355017 medRxiv
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Use of zooprophylaxis as a malaria control strategy has been recommended historically, but a complex relationship exists between animal ownership and malaria infection, with mixed associations described in the literature. We sought to characterize this relationship spatially and temporally in malaria-endemic regions of Africa. We used data from 392,843 individuals from 66 Demographic and Health surveys from countries within Africa to investigate the association between household animal ownership and Plasmodium infection. We used Bayesian models with Integrated Nested Laplace Approximation to incorporate spatially varying coefficient processes, allowing the association of interest to vary over space, time, and within strata of vector species occurrence, land cover, and number of animals owned by households. Spatially varying intercept models showed that ownership of cattle, chickens/poultry, goats, horses/donkeys/mules, pigs, and sheep was broadly associated with malaria infection, with odds ratios ranging from 1.55 to 1.67. However, spatially varying slope models revealed considerable heterogeneity, with odds ratio estimates for all animal types demonstrating both protective and harmful effects varying from 0.33 to 3.33 both subnationally and across time. We found no evidence that modification by vector species, number of animals owned, and land cover fully explained the variation in estimates. Unobserved localized cultural, behavioral, or ecological factors likely modify the association between animal ownership and malaria prevalence. Further exploring the nature of this relationship over space and time will be important to understanding how context-specific One Health dynamics between humans, animals and the environment affect malaria prevention and control efforts.

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Perceived Social Support and Self-Efficacy as Mediators Between Health Literacy and Quality of Life Among Middle-Aged and Older Adults with Hypertension: A Cross-Sectional Study in Six Central Provinces of China

Zhao, Y.; Yun, Y.; Bai, T.; Xiong, L.; Ruan, Y.; Zhao, H.; Wang, W.; Wang, F.

2026-06-08 public and global health 10.64898/2026.06.06.26355051 medRxiv
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Abstract Objective: The onset of hypertension occurs at a younger age in China, and the relationship between health literacy and quality of life among middle-aged and older hypertensive patients remains unclear. This study explored whether perceived social support and self-efficacy mediate the association between health literacy and quality of life in middle-aged and older hypertensive patients. Methods: A questionnaire was administered to 1,015 middle-aged and older hypertensive adults from communities in six central provinces of China. The EQ-5D scale, Perceived Social Support (PSS) scale, Self-Efficacy Scale (SES), and Health Literacy Scale (HLS) were used to assess quality of life, social support, self-efficacy, and health literacy, respectively. Mplus 8.3 software was used to construct a structural equation model for path analysis. Results: The mean PSS, SES, HLS, EQ-5D, and EQ-VAS scores were 15.57{+/-}3.45, 10.61{+/-}2.41, 9.49{+/-}2.86, 0.88{+/-}0.18, and 71.06{+/-}17.49, respectively. Health literacy and quality of life scores significantly differed among middle-aged and older hypertensive patients, and both showed positive correlations with perceived social support and self-efficacy (both P<0.001). Perceived social support and self-efficacy exhibited a chain mediated effect on the relationship between health literacy and quality of life (EQ-5D utility index and EQ-VAS), accounting for 28.57% of the total effect of the EQ-5D utility index and 27.26% of that of the EQ-VAS. This study is the first to elucidate the mechanism by which health literacy influences quality of life in middle-aged and older hypertensive patients through the chain-mediated effect of perceived social support and self-efficacy. Conclusion : Health literacy is significantly correlated with quality of life in middle-aged and older hypertensive patients. This correlation can directly or indirectly explain the impact on quality of life through mediating pathways involving perceived social support and self-efficacy. Keywords: hypertensive patients, perceived social support, self-efficacy, health literacy, quality of life, mediating effect

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Epidemiology of Cervical Precancerous Lesions: Prevalence and Predictors from Pap Smear Screening in Hawassa City Hospitals, Sidama Region, Ethiopia. Institutional-Based Cross-sectional Study

Fisshatsion, A. B.; Zewude, Y. A.; Nisro, A. M.; Abebe, R. F.

2026-06-10 public and global health 10.64898/2026.06.09.26355254 medRxiv
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Background: Cervical cancer is the fourth most common cancer in women worldwide and remains a major public health challenge. In Ethiopia, it is the second leading cause of cancer deaths, with around 8,000 new cases and 6,000 deaths each year. Region?specific data on the prevalence and predictors of precancerous lesions remain scarce, yet such information is vital for guiding targeted reproductive health strategies. This study therefore examined the prevalence and predictors of cervical precancerous lesions among women aged 21-60 years undergoing Pap smear screening in public hospitals in Hawassa City, Sidama Region. Methods: An institution-based cross-sectional study was conducted among 241 women attending Pap smear screening at public hospitals in Hawassa City from March to August 2025. Sociodemographic and clinical data were collected via interviews and medical records. Lesions were classified based on the standardized international framework for reporting cervical cytology results from Pap smears per the Bethesda system. Multivariable logistic regression identified predictors p<0.05). Result: Of 241 women screened (mean age 35.3 years), cervical epithelial abnormalities were detected in 52 (prevalence 21.6%). Atypical squamous cells of undetermined significance was the most common abnormality (16.6%). Multivariable analysis showed HIV infection was significantly associated with precancerous lesions (AOR = 3.7, 95% CI: 1.69-8.12, p<0.05), while hormonal contraceptive use was protective (AOR = 0.27, 95% CI: 0.11-0.67, p<0.05). Conclusion: These results underscore the urgent need to strengthen cervical cancer prevention through targeted screening and early intervention. Integrating routine HIV testing with Pap smear programs would be especially valuable. Health authorities should expand accessible screening for women aged 21-60, with particular attention to those living with HIV, to help reduce the burden of precancerous lesions.

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Elevating the patient perspective: Qualitative evaluation of non-U.S. born care navigation on latent tuberculosis infection screening and treatment adherence

Ramzy, L. M.; Rahman, M.; Luque, M. O.; Rodrigues, K. K.; Belknap, R.; Venci, J. A.; Francis, B.; Ruckard, B. J.; Moran-Ibarra, W.; Rasulo, R. M.; Matadi, A.; Ramirez, M. G.; Thee, P. S.; McFeron, H. D.; Monson, S. P.; For the Tuberculosis Epidemiologic Studies Consortium,

2026-06-08 public and global health 10.64898/2026.06.04.26354954 medRxiv
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Purpose: The purpose of this study was to examine the barriers and facilitators experienced by non-U.S. born persons during the diagnosis and treatment of latent tuberculosis infection (LTBI) in primary care settings, including the impact of culturally and linguistically congruent care navigation. Design: 25 interviews with non-U.S. born patients, along with focus groups and surveys with 31 primary care team members and leadership, were conducted. Setting: The study was conducted within a network of Federally Qualified Health Center (FQHC) clinics. Participants: Participants were adult non-U.S. born patients with LTBI and FQHC care team members. A purposefully selected subsample of randomized participants was interviewed. Intervention: Care navigators followed participants randomized to receive care navigation after a positive test for tuberculosis (TB) infection and offered health navigation and education about the importance of TB screening and treatment. Method: Data collection was followed by thematic analysis guided by a critical ideological paradigm. Results: Culturally and linguistically congruent navigation emerged as central to potentially reducing barriers, fostering trust, and improving treatment continuity. Participants without navigation support reported confusion and disengagement from care, while those with culturally aligned navigators described clarity and comfort, with influence overall by intrinsic motivation, relational support, and culturally shaped beliefs about care. Conclusion: Care navigation that includes culturally and linguistically congruent navigators whenever possible may help increase LTBI treatment completion among non-U.S. born populations. Limitations of the study include the potential influence of cultural norms, power dynamics, and selection bias.

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Estimating COVID-19 Cumulative Incidence from Seroprevalence Surveys accounting for Time-Varying Seroreversion: A Fully Bayesian Methodology

Owusu-Boaitey, N.; Meyer, M. J.; Herrera-Esposito, D.; Bottcher, L.; Lukz, M.; Cook, S.; Stoto, M. A.; Kraemer, J. D.

2026-06-10 epidemiology 10.64898/2026.06.09.26355264 medRxiv
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Seroprevalence surveys reveal the extent of humoral immunity against pathogens such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and under some circumstances represent cumulative incidence of prior infection. However, antibody waning - or seroreversion - biases these estimates by reducing assay sensitivity in a time-varying manner. Because assay sensitivity decays over time, naively using serosurveys can substantially bias estimates of SARS-CoV-2 cumulative incidence and fatality rates. The Bayesian assay-specific, time-varying sensitivity adjustment developed in this paper can reliably correct for this bias and account for the delay between infection and serosurvey. In seroprevalence studies conducted in the United States in 2020, adjusting for time-varying sensitivity increased cumulative incidence by up to 1.4-fold, with an adjustment of 1.08 for a national study. Our estimates contrast with a previously published 2-fold adjustment that did not account for assay design. This suggests that previous analyses overestimated cumulative incidence by applying seroreversion corrections that did not account for assay-specific effects, or underestimated cumulative incidence by not applying seroreversion corrections. These biases imply fatality rate underestimation and overestimation, respectively. Our model provides a framework for design-specific time-varying sensitivity corrections in seroprevalence surveys for other pathogens.

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A wealth index based on two-component polychoric principal component analysis reduces urban bias and improves socioeconomic classification in low- and middle-income country surveys: a validation study using LSMS surveys

Vidaletti, L. P.; Dos Santos, A. M.; Hellwig, F.; Barros, A. J. D.

2026-06-08 epidemiology 10.64898/2026.06.01.26354245 medRxiv
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Background: The traditional wealth index, based on principal component analysis (PCA), used in the Demographic and Health Surveys (DHS) and Multiple Indicator Cluster Surveys (MICS), suffers from urban bias, distorting estimates of health inequality. We compared the traditional index (PEAR1) with an alternative two-component polychoric PCA index (POLY2) using annual expenditure from 12 LSMS surveys as the gold standard to determine which provides more accurate SEP measures for equitable policy targeting. Methods: We compared the traditional wealth index (PEAR1) with a two-component polychoric PCA approach (POLY2) using 12 LSMS (Living Standards Measurement Study) surveys (2015-2022) from 12 African countries. Annual household consumption expenditure was the gold standard. We assessed agreement using weighted Cohen's kappa and validated against education (proportion of households with secondary or higher education) using the concentration index (CIX) and slope index of inequality (SII). Results: The POLY2 index showed higher agreement with expenditure quintiles (average national weighted kappa = 43.3%) than the PEAR1 index (35.1%), with notable improvements in urban (43.5% vs. 27.5%) and rural (35.3% vs. 22.4%) areas. POLY2 also attenuated extreme household distributions observed in PEAR1. Education validation showed that POLY2 produced intermediate inequality gradients between the flatter expenditure-based gradient and the steeper PEAR1-based gradient. Conclusion: The POLY2 wealth index is superior to the traditional index, reducing urban-rural bias and providing more accurate socioeconomic classifications. Its adoption in large-scale surveys such as DHS and MICS is recommended to improve equitable monitoring of health inequalities in low- and middle-income countries.

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A Decade of the Center for Disease Control and Prevention's FluSight Influenza Forecasting

Hines, A. G.; Mathis, S. M.; Johansson, M. A.; Biggerstaff, M.; Reed, C.; Borchering, R.

2026-06-08 epidemiology 10.64898/2026.06.05.26354941 medRxiv
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Since the U.S. 2013/14 influenza season, the CDC's FluSight Challenge has provided a platform for evaluating influenza forecasting models and fostering collaboration across institutions. The Challenge aims to improve the science and enhance the utility of infectious disease forecasts for public health decision making. We analyzed ten years of submitted forecasts (2014/15-2019/20 (influenza-like illness seasons) and 2021/22-2024/25 (hospital admissions seasons)) across a range of model types, including statistical, mechanistic, machine learning, and hybrid models. Influenza-like illness (ILI) forecasts were evaluated using the exponentiated logarithmic score (skill metric) while hospital admissions forecasts were evaluated using the log transformed relative Weighted Interval Score. Corresponding potential performance differences were assessed using Wilcoxon rank-sum tests, and associations with team participation history were evaluated using Spearman's rank correlation. Model performance varied by season, and no single model type consistently outperformed others. In ILI seasons, statistical models generally performed better than mechanistic and machine learning models, though consistent differences were not observed in more recent hospital admissions seasons. Ensemble forecasts showed better overall performance across seasons, and the CDC's FluSight ensemble ranked among the top-performing forecasts every year. We also found a positive correlation between forecast accuracy and the number of years a team participated in the Challenge, with statistically significant associations in four seasons. These findings highlight the benefits of ensemble approaches and sustained engagement in improving forecasting performance, while also underscoring the continued value of forecast evaluation before and following the COVID-19 pandemic. Insights from the FluSight Challenge can guide future infectious disease forecasting efforts and support more effective public health preparedness.

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Limitations of cross-border containment strategies for Bundibugyo ebolavirus

Middleton, C.; Larremore, D.

2026-06-08 epidemiology 10.64898/2026.06.04.26354820 medRxiv
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An ongoing outbreak of Bundibugyo virus disease (BVD) in the Democratic Republic of the Congo was deemed a public health emergency of international concern in May 2026. To prevent cross-border importation, many countries, including the United States, Canada, India, Thailand, and Kenya have already proposed containment strategies, and others are likely to follow suit. How well (or poorly) are screening and quarantine containment measures are likely to work? We leverage established epidemiological theory and develop a mathematical model of traveler screening and post-arrival quarantine for BVD to answer this question. We find that traveler screening via symptom screening or molecular testing will miss the majority of infected travelers, and should be complemented by post-arrival quarantine and monitoring of sufficient duration to detect those with long incubation periods. Our findings underscore the limitations of border screening and the importance of complementary measures like post-arrival quarantine to prevent local importation of BVD.

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Temporal and climatic drivers of uncomplicated malaria in Ghana: A Region Generalised Additive Model analysis.

Akurugu, E.; Awine, T.; Seidu, B.; Peprah, N. Y.; Mohammed, W.; Boateng, P.; Abiwu, P. H. A. K.; Silal, S. P.

2026-06-09 infectious diseases 10.64898/2026.06.06.26355054 medRxiv
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Abstract Background Malaria remains a major public health challenge in Ghana, despite recent reductions in cases due to various interventions. The endemicity of the disease varies across regions, influenced by diverse seasonal and temporal factors that support mosquito proliferation and malaria cases. This study used a Generalised Additive Models to explore the impact of weather conditions on malaria cases in Ghana. Methods Generalised Additive Models were used to examine the nonlinear effects of weather conditions on malaria cases. Monthly aggregated malaria cases from the District Health Information Management System II and average monthly rainfall and temperature data from the Ghana Meteorological Agency were analysed, covering 2012 to 2023. Regional Generalised Additive Models incorporating weather variables were developed, fitted, and validated against observed data using model diagnostics to identify the most suitable model for each region. Results The analysis revealed complex temporal patterns in malaria cases across Ghana, influenced by seasonal and long-term trends. Regions constituting the Coastal and Transitional Forest zones exhibited bimodal peak malaria seasons, while the Guinea Savannah showed a unimodal peak. Significant interactions between rainfall and temperature were identified, particularly in the Eastern region, where higher rainfall combined with temperatures around 27-28 {degrees}C were associated with higher malaria cases, reflecting the complex and region-specific nature of meteorological influences. Conclusions The findings point to the dynamic and heterogeneous nature of malaria caseloads in Ghana, emphasising the need for region-specific control strategies tailored to local climatic conditions. A key recommendation is the systematic integration of meteorological data into the National Malaria Data Repository to enable continuous monitoring of climatic influences and support timely, evidence-based intervention decisions. Future research should incorporate socio-economic factors, intervention coverage data, vector surveillance, and demographic characteristics into mathematical modelling frameworks for a more comprehensive understanding of malaria cases in Ghana.

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Pooled testing for SARS-CoV-2 surveillance in schools: real-world evaluation of transmission control, testing resources, and educational disruption

Colosi, E.; Calmon, L.; Fässli, M.; Koch, K.; Bielicki, J. A.; Colizza, V.

2026-06-04 infectious diseases 10.64898/2026.06.03.26354821 medRxiv
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Pooled testing programs were introduced during the COVID-19 pandemic to expand surveillance capacity while preserving testing resources, but evidence on their epidemiological impact in schools under real-world conditions remains limited. We analyzed data from the pooled testing program implemented in public primary schools of the canton of Basel-Landschaft, Switzerland, during the Fall-Winter 2021 Delta wave. We used an agent-based transmission model informed by pooled and individual testing results, school characteristics, contact networks, and community incidence. The model was fitted to pooled positivity ratios in four clusters of administrative areas with similar epidemic trajectories. We compared pooled testing with alternative protocols in terms of school transmission, testing volume, and student-days lost. During the study period, pooled testing was offered to 21'187 students across 62 public primary schools, with high and stable participation across clusters (mean 71-79%). The fitted model reproduced observed pool positivity trends well. Compared with pooled testing, reactive class closure, reactive screening, and symptomatic testing were associated with higher in-school transmission, with excess ranging from 50% to 87%, 63% to 104%, and 72% to 133% across clusters. Weekly individual screening achieved similar reductions in transmission but required 15-25 times more tests. Relaxing class closure after depooling substantially reduced student-days lost without increasing transmission. Under real-world conditions, pooled testing provided an effective and resource-efficient strategy to reduce SARS-CoV-2 transmission in primary schools. Combining early detection of asymptomatic infections with low testing demands, pooled testing offers a scalable approach to school surveillance and control for pandemic response in educational settings.

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Gendered pathways to adolescent mental health: An empirical assessment of a new conceptual framework

Alaze, A.; Hagen, D.; Schamberger, T.; Razum, O.; Miani, C.

2026-06-10 epidemiology 10.64898/2026.06.09.26355310 medRxiv
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Introduction Gender norms and roles are important determinants of physical and mental health in the key period of adolescence. Yet, the gendered pathways to mental health in adolescents are not fully understood. Using a conceptual framework for global adolescent mental health that we developed based on a Delphi process, we empirically investigated the associations between six gender-related constructs and adolescent mental health. Methods We used cross-sectional Gender and Adolescence: Global Evidence (GAGE) data from Ethiopia (2020) to explore the associations between sex, gender norms, psychological competencies, gender attitudes, gender roles, with the latter two also serving as mediators, and psychological distress (GHQ-12), using Structural Equation Modelling (SEM). Results The SEM model contained measurements from 1,584 adolescents, including 843 girls and 741 boys, with a median age of 13 years. Out of 14 pathways tested, we found statistically significant associations between psychological competencies and psychological distress; sex and gender attitudes; and between gender norms and psychological competencies, gender attitudes, and gender roles. Hence, the gender-related constructs were mostly associated with each other, rather than with psychological distress. Conclusion The gender-related constructs are strongly interrelated, thereby attenuating their individual effects on psychological distress. The interplay of gender-related constructs should be considered when developing interventions to promote mental health in adolescents.

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Knowledge, attitudes and practices regarding risk factors for cardiovascular disease among women in an urban slum of Kathmandu, Nepal: A cross-sectional study.

Kasaju, M.; Shrestha, A. P.; Oli, N.; Vaidya, A.

2026-06-08 public and global health 10.64898/2026.06.04.26354909 medRxiv
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Introduction: Cardiovascular diseases (CVDs) are the leading cause for death and disability worldwide accounting for 75% of deaths in low- and middle-income countries (LMICs) like Nepal. Urbanization and globalization remains the major cause of rise in CVDs among urban poor population along with growth in slum settlements. This study aims to assess the knowledge, attitude and practice (KAP) of CVDs and its risk factors among women of one such urban poor community in Nepal. Methodology: This cross-sectional study (n=388) in the Sinamangal-Minbhawan slum area was conducted using semi structured questionnaire based on STEPs survey and HARDIC study among the participants selected through convenient sampling. Descriptive analysis was done using SPSS version 21 and KAP scores were further categorized based on median score to perform multivariate logistic analysis. Additionally, Anthropometric and blood pressure measurements were also recorded and analyzed. Results: The median age (Interquartile range) of participants was 33 years (17) with majority of them being Dalit by ethnicity, housewives, with up to primary level education belonging to upper lower socioeconomic class. More than half (53.3%) of the participants were obese and over 23% were hypertensive. While half of the hypertensive women were aware of their status, only 3% had their blood pressure under control.The median knowledge, attitude and practice (KAP) scores were 12, 60 and 10 respectively. The KAP scores were positively associated with socioeconomic status of the participants. Conclusion: The study revealed low knowledge with high prevalence of behavioral risk factors of CVDs along with high prevalence of other metabolic risk factors like high body mass index, high waist hip ratio and hypertension among women of slum area with a positive attitude to prevent CVDs and its risk factors.

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A policy for delivery of essential medicines to vulnerable population in Argentina: a case study of the REMEDIAR program

Havela, M.; Bartolomeu, L.; Rubinstein, A.

2026-06-08 health systems and quality improvement 10.64898/2026.06.05.26354987 medRxiv
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Essential medicines are one of the cornerstones of financial protection and health equity. The REMEDIAR Program is an initiative of the Argentine Ministry of Health aimed at ensuring free access to essential medicines for the uninsured at the point of care in primary healthcare centers (PHC). This study analyzes the financing, procurement, and distribution of this program over two decades (2002 to 2024). It evaluates how the program's capacity to navigate economic and political challenges ensured an uninterrupted supply of essential drugs at the primary healthcare level in a federal country where health services are devolved to provinces. We adopted a mixed-methods approach to examine the duality between international concessional loans and domestic treasury funding. Findings reveal that while international financing enhanced predictability and efficiency, reducing procurement timelines from 458 to 235 days, it also constrained domestic planning through external conditionalities. Conversely, while national centralized procurement achieved superior price efficiency and lower dispersion, it faced rigidities in adapting to local needs. Territorial distribution analysis confirms that REMEDIAR reduced access barriers for vulnerable households without formal insurance. However, the program entered a stabilization phase, failing to consolidate robust coordination with subnational policies, becoming entrenched in its own operational logic. The study concludes that program effectiveness depends not only on resource volume but on management quality. To guarantee long-term sustainability, transition to national financing requires profound institutional redesign. This must integrate operational capacities with federal coordination and domestic regulations, ensuring that the primary healthcare supply chain remains resilient to macroeconomic volatility and political shifts, aligned with sub-national strategies.

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A Comparison of Manual and Automated Approaches to Developing Computable Algorithms for Identifying Acute Pancreatitis

Bann, M. A.; Carrell, D. S.; Gruber, S.; Heagerty, P. J.; Williamson, B. D.; Nelson, J. C.; Hazlehurst, B.; Felcher, A.; Nyongesa, D. B.; Slaughter, M. T.; Sapp, D. S.; Cronkite, D. J.; Ball, R.; Floyd, J. S.

2026-06-08 health informatics 10.64898/2026.06.05.26354934 medRxiv
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Objective: Clinical phenotyping methods that rely on clinical and informatics expertise can be time-intensive and costly. We tested both manual and highly automated approaches using electronic health record (EHR) data to identify an FDA Sentinel Initiative health outcome of interest, acute pancreatitis. Materials and Methods: We trained and evaluated machine learning algorithms using EHR data with two approaches: a custom approach that included manually curated features and trained on outcomes data validated with medical record review, and a highly automated approach that greatly simplifies and automates feature engineering and relies on low-cost silver-standard outcomes for model training. Results: Custom algorithms using manually curated structured claims data discriminated cases from non-cases with a high degree of accuracy (cv-AUC 0.89 [95%CI 0.84-0.94]); the inclusion of natural language processing (NLP)-derived covariates from clinical notes increased performance slightly (cv-AUC 0.91[95%CI 0.86-0.97]). The automated algorithm trained on the outcome count of diagnosis codes performed less well (AUC 0.80 [95% CI 0.75-0.85]) but improved using maximum lipase value as an outcome (AUC 0.88 [95% CI 0.84-0.92]). At a positive predictive value of 90%, the custom algorithm had a sensitivity of 92%, the automated algorithm trained on diagnosis code count had a sensitivity of 45%, and the automated algorithm trained on maximum lipase value had a sensitivity of 84%. However, a prediction rule derived by clinicians during chart review was nearly as accurate (maximum lipase value [&ge;] 3 times upper limit of normal; AUC 0.86, PPV 85%, sensitivity 92%). Discussion: Machine learning algorithms with manually curated structured data and NLP features trained on validated outcomes data successfully identified validated events. Use of an outcome in the automated model based on specific phenotype knowledge (maximum lipase value) allowed for performance similar to the custom model and with considerably less resources.

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Within-household transmission risk of pulmonary tuberculosis in the era of universal antiretroviral therapy

Khan, P. Y.; Govender, I.; McCreesh, N.; Sithole, M.; Mkwanzai, E.; Sweeney, S.; Ording-Jespersen, G.; Wong, E. B.; Hanekom, W.; Houben, R. M. G. J.; White, R. G. M. G. J.; Smit, T.; Smith, M. J.; Fielding, K.; Grant, A. D.

2026-06-09 epidemiology 10.64898/2026.06.01.26354571 medRxiv
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Background Tuberculosis remains the leading infectious cause of death worldwide. In the WHO African region, declining incidence has coincided with antiretroviral therapy (ART) scale-up, though whether this reflects reduced progression to disease or reduced transmission is unclear. We evaluated how ART and symptom status influence within-household Mycobacterium tuberculosis complex (MTBC) transmission risk. Methods We conducted a case-contact household study in rural South Africa, enrolling index adults with bacteriologically-confirmed pulmonary tuberculosis. MTBC immunoreactivity was measured in all child household contacts (aged 2-14 years) as a proxy measure of within-household transmission. We assessed the influence of index person ART status and symptom status, and explored effect-measure modification of the association between index person HIV status and transmission risk by sex. Results Among 755 child contacts of 296 index persons, effective ART was not associated with within-household MTBC transmission risk (risk ratio [RR], 1.07; 95% CI, 0.66-1.74). Among PLHIV engaged in ART care, WHO TB four-symptom screen (WHO4SS) status was not associated with transmission risk (RR, 0.80; 95% CI, 0.43-1.47), although absence of reported cough reduced risk (RR, 0.61; 95% CI, 0.38-0.96). A pronounced interaction between sex and HIV status was observed: HIV-negative women had the highest within-household MTBC transmission risk (30.5% vs. 14.3% in women with HIV) whereas risks were similar between HIV-positive and HIV-negative men. Conclusions We found no evidence that effective ART or WHO4SS status influenced within-household MTBC transmission risk, though confidence intervals were wide. Absence of reported cough was associated with lower risk, and transmission risk was highest among child contacts of HIV-negative women. These findings suggest reported cough is a useful marker of transmission risk and that routine tuberculosis screening within ART care may reduce transmission from PLHIV; intensified efforts are nonetheless needed to achieve earlier tuberculosis detection in HIV-negative individuals.

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Compositional microbiome-based signatures associate with general health status: findings from a large population-based cohort study

Pujolassos, M.; Kurilshikov, A.; Weersma, R. K.; Yang-Fu, J.; Zhernakova, A.; Calle, M. L.

2026-06-04 epidemiology 10.64898/2026.06.03.26354796 medRxiv
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While microbiome is increasingly recognized as crucial for human health, translating this knowledge into effective healthcare and preventive strategies remains challenging. Many studies focus on identifying changes in microbiome composition associated with disease and evaluating the potential of such disease-associated microbial profiles as biomarkers for disease diagnosis. Under the hypothesis that microbiome dysbiosis may reflect physiological alterations present long before disease onset, in this work, we analyse the potential of disease-specific microbial signatures not as a diagnostic tool when the disease is already present, but as a means of health assessment in the general population. Moreover, instead of trying to define a single health measure, we believe it is necessary to consider several ways in which the microbiome departs from health, according to different disease-related physiological changes. To evaluate our assumptions, we designed a two-stage study: the identification of disease-specific microbial signatures (discovery stage) and, subsequently, the study of their distribution in the general population to assess associations with general health (external validation stage). Specifically, in the discovery phase we characterized 16 disease-specific bacterial signatures from large public microbiome data using a compositional data analysis methodology. In the second phase, we quantified these microbial signatures in the Lifelines-DMP cohort, a large population-based cohort, and evaluated their association with self-reported health status. Results indicate that most disease-specific microbial signatures associate with health status, supporting our assumption that microbial composition can capture physiological alterations before disease onset, and highlighting the importance of considering multiple ways in which microbiome departs from a healthy state. These findings reaffirm the potential of microbial information as an additional tool in preventive medicine.