Tropical Medicine and Infectious Disease

Background: Treponema pallidum quantitative polymerase chain reaction (qPCR) positivity and cycle threshold (Ct) by rapid plasma reagin (RPR), disease stage, and other characteristics are poorly characterized in routine-care specimens, leaving it unclear when qPCR of such specimens is informative for diagnosis. Methods: This Japanese multicenter cross-sectional study explored qPCR positivity and Ct by these characteristics. Nonblood specimens collected during routine care underwent qPCR at a central laboratory for this study. Bayesian logistic and normal regressions modeled positivity and mean Ct of TP0574 and polA with stage-specific continuous automated RPR terms, patient characteristics, collection site, and facility random intercepts. Estimates were standardized over the analyzed specimens. Population-group predictions were instead averaged within each group. Results: Among 154 nonblood specimens from 145 patients (71.7% non-MSM men and women) at 14 facilities, 109 (70.8%) were qPCR positive. At RPR 1, adjusted positivity was 72.2% (95% credible interval, 60.9%--82.9%) in primary and 43.8% (16.7%--69.9%) in secondary syphilis. Positivity showed a modest downward trend with RPR in primary but increased in secondary syphilis, reflecting a stage-by-RPR interaction (secondary-to-primary ratio of odds ratios, 1.78; 1.25--2.65). Predicted positivity showed an upward trend with RPR values among MSM; adjusted positivity was relatively high for genital/urethral/urinary and anal/perianal/rectal specimens. Adjusted mean Ct increased with RPR in primary and followed an inverted-U pattern in secondary syphilis. Conclusions: In primary syphilis, nonblood qPCR positivity was high even at low RPR. When serologic findings remain inconclusive in this stage, qPCR is highly recommended for securing an early diagnosis.

Background Malaria and HIV remain major causes of illness in sub-Saharan Africa, accounting for 94% of the global malaria burden and over two-thirds of the global HIV burden. HIV-related immunosuppression increases susceptibility to malaria, with a higher malaria burden of up to 47% and severe malaria complications compared to HIV-negative individuals. Socio-demographic factors, individual knowledge, attitude, and perception are recognized determinants of malaria prevention behaviours, but no study has modelled their combined contribution, and there is scant research on these factors among people living with HIV. We assessed the level of knowledge, attitudes, and perceptions towards malaria, and identified the predictors of malaria prevention practice among HIV-positive individuals in Kampala, Uganda. Methods This cross-sectional study enrolled 620 HIV-positive patients attending the ART clinic of China-Uganda Friendship Hospital, Naguru, selected by systematic random sampling. Data collection was conducted from 21st July 2025 to 18th August 2025 using a structured, interviewer-administered questionnaire that measured socio-demographic characteristics, knowledge, attitude, perception, and the practice of malaria prevention. Associations were assessed using Mann-Whitney U, Kruskal-Wallis H, and Spearman correlation. The independent predictors of good malaria prevention practice were identified using binary logistic regression. Results Participants had a mean age of 34.8 years, were predominantly female (68.9%), Baganda (38.1%) by tribe, and the majority had a secondary level of education(46.0%). Most had good knowledge of malaria (97.3%) and a positive attitude (90.5%), while 57.3% held a positive perception of malaria risk and prevention; only 62.6% reported good malaria prevention practice, and most prevention methods used were sleeping under a mosquito net (71.1 3%) and closing windows early in the evening (70.3%). In regression analysis, knowledge (adjusted odds ratio [AOR] 1.198, 95% CI 1.03-1.40, p = 0.023) and attitude (AOR 1.101, 95% CI 1.04-1.17, p = 0.001) independently predicted good practice, while perception did not (AOR 1.00, 95% CI 0.96-1.04, p = 0.994). Scores of Attitude, perception, and malaria prevention practices varied significantly, though non-linearly, by education level, and were highest among non-educated participants. Conclusions Despite near-universal knowledge and predominantly positive attitudes in this study, more than a third of HIV-positive participants did not practice adequate malaria prevention, and perception did not independently predict malaria prevention practice once knowledge and attitude were accounted for. Programmes seeking to close this know-do gap should pair health education with structural support for prevention tools rather than education alone.

Objectives To assess microfilaraemia, chronic lymphatic filariasis (LF)-related morbidity, and community knowledge and self-reported preventive behaviours in a rural community in northern Ghana following prolonged mass drug administration (MDA). Design Community-based cross-sectional study. Setting Birifor community, Lawra Municipality, Upper West Region, northern Ghana, from October 2024 to January 2025. Participants A total of 261 community members aged 10 years and above were selected using random sampling and participated in the study. Outcome measures Outcome measures included microfilaraemia detected by night blood microscopy, chronic LF-related morbidity identified through clinical examination, and community knowledge and self-reported preventive behaviours assessed using a structured questionnaire. Results No microfilariae were detected (0/261; 0%). Chronic lymphoedema was identified in five individuals (1.9%), all aged over 40 years. Awareness of LF was high (95.8%), yet only 39.5% of participants demonstrated good community knowledge and self-reported preventive behaviours. Misconceptions regarding transmission, particularly beliefs that LF is hereditary or caused by spiritual factors, were common. MDA participation was high (93.1%). All five individuals with chronic lymphoedema reported loss of income, and three (60%) reported additional household income loss due to caregiving responsibilities. Conclusions No microfilaraemia was detected, suggesting very low transmission in the study area, although residual infection cannot be excluded. Chronic LF-related morbidity and gaps in community knowledge persist despite high MDA participation. Sustained surveillance using more sensitive diagnostic approaches, together with morbidity management and disability prevention, community education and support for affected households, will be important to sustain LF elimination efforts.

Aim: Brucellosis remains endemic throughout the Mediterranean basin, the Middle East and Central Asia. Genitourinary involvement is an uncommon but clinically consequential focal complication that closely mimics urological emergencies and may precipitate unnecessary surgery. Contemporary data describing its frequency, laboratory signature and treatment outcomes in endemic settings remain limited. Material-Methods: We retrospectively screened all adults ([≥]18 years) with confirmed brucellosis managed at a tertiary infectious diseases unit between January 2008 and December 2020. Genitourinary involvement was defined as epididymo-orchitis, orchitis, epididymitis and/or brucellar pyelonephritis. Clinical, laboratory, ultrasonographic, therapeutic and outcome variables were abstracted using a standardised form. Proportions are reported with Wilson score 95% confidence intervals (CI). Reporting followed the STROBE statement. Result: Genitourinary involvement was identified in 18 of 125 patients with brucellosis (14.4%; 95% CI 9.3-21.6); 16 (88.9%) were men and the mean age was 35.2 years (range 22-62). Scrotal disease dominated the male presentation: epididymo-orchitis in 10 of 16 men (62.5%; 95% CI 38.6-81.5), orchitis in 4 (25.0%) and epididymitis in 2 (12.5%). Both women presented with pyelonephritis, one of whom developed a tubo-ovarian abscess requiring drainage. Constitutional features were near-universal (fatigue 100%, night sweats 88.9%, fever 77.8%). Leukocyte counts remained within the reference interval in every patient (mean 5,680/mm3), whereas erythrocyte sedimentation rate (mean 32 mm/h) and C-reactive protein (mean 24.2 mg/L) were only mildly to moderately raised. The Coombs anti-Brucella test was positive in 18 of 18 patients (100%) and the standard agglutination test in 17 of 18 (94.4%), whereas blood culture yielded Brucella melitensis in only 1 of 18 (5.6%). Concomitant extragenitourinary focal disease was present in 8 patients. All patients received doxycycline plus rifampicin; none required modification of the regimen or orchiectomy, and no treatment failure occurred (0 of 18; 95% CI 0-17.6). Median follow-up was 12 weeks (range 6-52) and no relapse was documented within this interval. Conclusions: In endemic regions, genitourinary brucellosis should be suspected in any patient with acute scrotal or flank symptoms accompanied by constitutional complaints, even when the leukocyte count is normal and acute-phase reactants are only marginally elevated. Coombs anti-Brucella serology rather than blood culture is the diagnostic cornerstone, and prompt doxycycline-rifampicin therapy averts surgical intervention.

Long-acting injectable human immunodeficiency virus (HIV) medicines expand treatment and prevention choices, but willingness to use them does not establish readiness to begin. We examined readiness to start these options, associated factors and conditions for acceptance among people living with HIV and pre-exposure prophylaxis (PrEP)-service clients in Uganda. This cross-sectional study analysed 225 participants at Mildmay Hospital and Kajjansi Health Centre IV in central Uganda. Readiness meant preferring initiation immediately or within three months. Modified Poisson regression estimated adjusted prevalence ratios (aPRs) and 95% confidence intervals (CIs), including age-by-service-group interaction. Separate models examined informational, perceptual and financial factors, adjusting for service group, age and sex. Logistic marginal standardisation checked demographic and expanded age comparisons. Overall, 108 participants (48.0%) were ready to start injectable HIV treatment or prevention, 111 (49.3%) wanted more information about these options, and six (2.7%) preferred initiation in six to twelve months. Readiness was 80.8% among people living with HIV aged 15-24 years and 34.4% among those aged 25 years or older (aPR 2.35, 95% CI 1.63-3.38). Corresponding proportions among PrEP-service clients were 39.2% and 41.4% (aPR 0.95, 95% CI 0.60-1.50; interaction p=0.002). In separate adjusted models, clinic-staff information (aPR 1.94, 95% CI 1.42-2.66), belief in greater effectiveness (2.00, 1.43-2.80) and a one-point increase in benefit score (3.27, 2.36-4.55) were associated with higher readiness. A one-point increase in concern score (0.70, 0.60-0.80) and financial difficulty sometimes or more often (0.68, 0.48-0.96) were associated with lower readiness. Fewer side effects was the leading condition for accepting injectable HIV treatment or prevention across service and readiness groups. Nearly half of participants were ready to start, while a similar proportion wanted further information about injectable options. Programmes should assess intended initiation timing alongside willingness and address safety, appointment flexibility, privacy and affordability through counselling and service planning.

Background: Localized or segmental overgrowth is a rare condition that may co-occur with vascular malformations. These diseases generally are caused by somatic mutations in the PI3K/AKT/mTOR pathway. Most lesions are progressive and may cause symptoms including pain, functional impairment, and disfigurement. Treatment options are limited, especially for the overgrowth component. Objective: To evaluate the efficacy and safety of the mTOR inhibitor sirolimus in patients with overgrowth with or without a vascular malformation over a 6-months treatment period. Methods: We conducted a single-arm, open-label, phase II study including 18 patients (12 pediatric, six adult) with overgrowth, all of whom initiated oral sirolimus. 16/18 (88.9%) participants received oral sirolimus for 6 months, with dosing adjusted to achieve target blood trough levels of 3-8 ng/mL. Primary outcome was radiological response at six months assessed by the Response Evaluation Criteria in Solid Tumors (RECIST) 1.1. Secondary outcome parameters were evaluated at three, six and nine months and included size and visual appearance of the overgrowth, quality of life (QoL), pain intensity, performance status, and safety. Results: No patient achieved complete or partial radiological response. 17 of 18 patients (94.4%) maintained stable disease at month six; one was not evaluable. QoL measured with WHOQOL-BREF improved modestly in patients aged >= 18 years (n=5, mean difference to baseline +9.3 (95%-CI: -0.9 to 19.5) in physical and +9.2 (95%-CI: 0.7 to 17.7) in psychological domains at month 6). In pediatric participants, no relevant improvement in KINDL total scores was observed over the study period. No significant changes occurred in pain scores. Performance status measured by the Lansky/Karnofsky scales showed minor improvement (mean +3.5 points (95%-CI: 1.0 to 6.1)). All patients experienced at least one adverse event, but no serious adverse events or CTCAE v5.0 grade [≥]3 toxicities occurred. Sirolimus was well tolerated. Six patients decided to resume sirolimus after study completion. Conclusions: Sirolimus induced minor lesion shrinkage in a subset of patients, although this did not meet the predefined radiological RECIST endpoint. However, sirolimus can lead to functional improvement in some adults, which may indicate that the primary radiological outcome did not capture patient-perceived benefit.

Wolbachia-based interventions were less effective in achieving introgression in Rio de Janeiro than other settings. Reduced introgression occurred in locations where dengue was historically high, raising concerns of inequity. We examined factors affecting Wolbachia introgression in Rio through trajectory modeling, spatiotemporal Bayesian models, and Ae. aegypti abundance estimation. During the intervention (2017-2020), Wolbachia introgression was 26% (median; IQR,14-44%), with four distinct trajectories. Despite receiving more releases, densely populated areas with low socioeconomic status had lower introgression. In spatiotemporally explicit multivariable regressions, higher Ae. aegypti abundance, temperature, population density and lower socioeconomic status were associated with reduced introgression. Improved characterization of Ae. aegypti abundance and other structural/environmental predictors of introgression could be used to calibrate release doses to ensure equitable benefits from Wolbachia interventions.

Background The abrupt withdrawal and uneven restoration of United States PEPFAR support in 2025 disrupted HIV service delivery in aid-dependent countries worldwide. In Zambia, decreases in HIV service delivery have been documented at a national level, but variations by facility and by quarter have largely been masked by existing aggregate district- and province-level estimates. We examined facility-level variation in HIV service volumes delivered before and after the funding cuts. Methods We analysed monthly District Health Information System (DHIS2) data covering testing volumes, ART initiations, and numbers on ART for January 2024-December 2025) for two sets of facilities: 1) 24 selected SENTINEL network facilities across four provinces (Central, Copperbelt, Lusaka, and Southern); and 2) all facilities in two districts, Chongwe in Lusaka Province, which was supported by the U.S. CDC under PEPFAR, and Mpongwe in Copperbelt Province, which was supported by USAID under PEPFAR. For each facility, we calculated quarterly 2025:2024 ratios of service volumes and summarized quarterly and annual percentage changes in numbers of tests, treatment initiations, and clients on ART. Results Aggregate HIV testing volumes declined 18% in SENTINEL facilities from 2024 to 2025, with 17 of 24 facilities showing net annual decreases. Aggregate ART initiations declined 16%, with 23 of 24 facilities experiencing net decreases. For both indicators, variation between quarters and among individual facilities matched or exceeded aggregate changes. Numbers of clients currently on ART were comparatively stable, with only 6 facilities showing net declines exceeding 5%. District-level analyses showed divergent patterns. Net aggregate testing volumes increased by 7% in Chongwe District, but 28/39 facilities experienced quarterly declines exceeding 10% in at least one quarter and fell by 40% in Mpongwe District overall. Only 4 of 36 sites in Chongwe showed a net loss of clients over the course of 2025, with most experiencing gains, while Mpongwe experienced substantial variation by facility, with many having declines of >30% during some quarters and 14 of the 25 facilities suffering a net loss from 2024 to 2025. Conclusions Facility-level performance varied substantially within the same district following the 2025 PEPFAR funding disruptions, with some sites losing most of their service volumes while others remained stable or exceeded 2024 levels. These findings emphasize the need for facility-level monitoring to target recovery support where it is needed most.

The COVID-19 pandemic substantially disrupted tuberculosis (TB) prevention, diagnosis, and treatment services worldwide. Despite increased TB notifications in Nepal during the post-pandemic recovery period, the geographic distribution and temporal clustering of notifications remain poorly understood. This study examined the spatial and temporal patterns of TB notifications across Nepal during the COVID-19 recovery period. We conducted a nationwide retrospective ecological analysis of district-level TB notifications across all 77 districts of Nepal from FY 2019/20 to FY 2023/24. Space-time, purely spatial, and purely temporal scan statistics were performed using a discrete Poisson model in SaTScan. Statistical significance was assessed using Monte Carlo simulation with 999 replications. A total of 172,155 TB cases were notified during the study period. TB notification rates increased by 51%, from 92 to 139 per 100,000 population between FY 2019/20 and FY 2023/24. Four statistically significant high-notification space-time clusters were identified (all p < 0.001). The primary cluster included Kathmandu, Lalitpur, Bhaktapur, Makwanpur, Bara, and Parsa districts during FY 2021/22-FY 2023/24 (RR = 1.60). Additional clusters were identified in western Nepal, the eastern Terai, and Rupandehi district. Purely temporal analysis showed a nationwide increase in notifications during FY 2022/23-FY 2023/24 (RR = 1.26, p = 0.001). TB notifications increased substantially during Nepals post-pandemic recovery period, with marked geographic and temporal heterogeneity. Integrating spatial and temporal surveillance may help identify areas requiring geographically targeted TB control strategies.

In England and Wales, Usutu virus (USUV) was detected in 2020 and is now established. West Nile virus (WNV) has so far only been detected in a single location, in two Aedes vexans mosquito pools sampled during 2023 surveillance. Given the growing threat to the UK from Culex-borne viruses there is a need to undertake risk assessments to contribute to preparedness and surveillance strategy for both viruses across human and animal health sectors. Here, we present the first application of a mechanistic R0-based model, incorporating temperature dependence and combining data on vector species distribution with projected future climate scenarios, to assess transmission suitability for WNV and USUV across England and Wales. Under current climate conditions, the two viruses showed comparable spatial patterns, with risk concentrated most heavily in the southeast along the Thames estuary and extending into Kent, Essex and Surrey, as well as around Cambridgeshire and adjacent counties, and across Yorkshire, Nottinghamshire and Lincolnshire. This pattern broadly corresponded with the cumulative distribution of Culex mosquito abundance established in our earlier work (Culex pipiens pipiens, Culex pipiens molestus and Culex torrentium). Both viruses were projected to show increasing transmission suitability risk over time, with substantially steeper increases under Representative Common Pathway (RCP) 8.5 then RCP 4.5. Equine WNV cases were predicted to be most likely in southeast England, in particular around Newmarket, driven by the region's dense horse population. Among the human population, London was identified as the highest-risk area, with Liverpool and Manchester also showing elevated risk levels, driven by a combination of high human and mosquito distributions. When human population distributions were age-adjusted to account for the proportion of over 60 years-olds, there was elevated risk in coastal regions, particularly in the east (Norfolk and Suffolk) and southeast (Kent) of England. The geographic distribution of positive mosquito and bird USUV cases recorded in 2023 and 2024 broadly overlapped with areas predicted to have higher USUV suitability, providing validation for the model's spatial outputs. By characterising relative spatial transmission suitability risk, this work adds to a growing understanding of where arbovirus emergence and spread are most likely across England and Wales, and can support decisions around resource allocation, targeted surveillance efforts, and public health readiness. The results also underscore the importance of incorporating climate change and vector ecology into future modelling work, given their likely influence on how arbovirus risk evolves over time.

Urogenital schistosomiasis, caused by Schistosoma haematobium, remains a major public health challenge among school-aged children in rural Ghana. Although urogenital indicators are well-established, systemic hepatic biomarker alterations in post-mass drug administration pediatric settings remain poorly characterized. This cross-sectional study evaluated point-of-care urinalysis profiles alongside a panel of serum hepatic and renal biomarkers in 174 children (aged 3 to 16 years) from the Sene West District, Ghana. Active infection (urine microscopy egg detection) was identified in 84 participants (48.3%, median egg count = 4.50 eggs/10 mL, IQR: 1.00 - 9.25). Active infection was strongly associated with microhematuria (57.1% vs. 11.1%, p < 0.001), proteinuria (42.9% vs. 22.2%, p = 0.004), and leukocyturia (27.4% vs. 4.4%, p < 0.001). Children with active infection also demonstrated a higher frequency of composite categorical hepatic biomarker alterations (60.7% vs. 37.8%, p = 0.002), whereas categorical renal alterations showed no significant difference (p = 0.332). Controlling for age and sex, multivariable logistic regression confirmed active infection as a significant independent predictor of composite hepatic biomarker alterations (aOR = 2.54, 95% CI: 1.37 - 4.69, p = 0.003), but not renal alterations (aOR = 1.40, p = 0.359). Continuous medians for individual serum biomarkers showed no significant differences between groups. Combining composite hepatic biomarker thresholds with routine dipstick screening improves the detection of subclinical morbidity in pediatric field settings.

Neoehrlichia mikurensis is widely detected in tick populations across Europe, yet its host range beyond small rodents remains poorly understood. Large wild mammals are frequently exposed to tick vectors, but their role in the transmission cycle of this bacterium is unclear. Wild boars (Sus scrofa) are among the most abundant large mammals in southern Sweden and commonly inhabit tick-infested environments, making them a potentially relevant host species. In this study, spleen samples from 87 wild boars collected between 2023 and 2025 across southern and central Sweden were analysed for the presence of N. mikurensis DNA using quantitative polymerase chain reaction. N. mikurensis DNA was not detected in any of the analysed samples, despite sampling in regions where the bacterium is known to be prevalent in ticks. These results indicate that wild boars may have a limited role in the maintenance of N. mikurensis in Sweden, although the possibility of rare or transient infection cannot be excluded. Despite being based on negative findings, this study contributes to a more comprehensive understanding of the host range of N. mikurensis and highlights the importance of continued evaluation of wildlife species in the transmission dynamics of tick-borne pathogens.

Background. Nigeria's reported Lassa fever case fatality ratio (CFR) rose from 18.9% at week 23 of 2025 to 25.0% in 2026, prompting concerns over failing clinical care. Because surveillance artefacts can also alter CFRs, candidate mechanisms that published data can resolve were identified and evaluated. Methods. This ecological study extracted weekly state-level counts from 474 Nigeria Centre for Disease Control and Prevention situation reports (2017-2026). Per a pre-specified plan, years were compared at phase-matched points, year-on-year CFR changes were decomposed into within-state and between-state components, and tipping-point ascertainment shifts calculated. Weekly incident and cumulative published totals were compared post hoc. Findings. Of 11 candidate mechanisms, 2 could be evaluated fully and 5 in part. On weekly incident counts, 2026 did not differ from 2025 at the phase-matched midpoint (+0.3 percentage points, 95% CI -5.0 to 7.6); within-state (-1.1, 95% CI -4.7 to 3.0) and between-state (+0.5, -2.0 to 2.9) components spanned zero. Conversely, the published cumulative CFR was 5.4 to 6.2 percentage points higher because 70 deaths were added retrospectively by week 36 outside weekly reports. Reconciling cumulative figures would require 279 missed survivors (6% of suspected cases not confirmed). Interpretation. The 2026 CFR rise came from deaths added to cumulative totals outside the weekly counts, and published data cannot attribute it to care. Endemic zoonotic CFRs cannot serve as clinical outcome measures unless testing volumes, deaths added late, and post-mortem sampling are published alongside case counts. Funding. US NSF-NIH-NIFA EEID; UK BBSRC; Birgitta Sintring Fellowship (Uppsala University).

Introduction: The continuing high and inequitable global malaria burden requires improved methods to understand trends and target control. Current methods often involve infection prevalence surveys, but additional parasitological measures could increase precision in estimating infection burdens of communities. Methods: Focusing on the country with most malaria globally, examinations of slides from 10,651 children under five sampled in the 2021 national Malaria Indicator Survey in Nigeria were performed to measure asexual parasite densities in infected children and discriminate sexual stages and species. Variation in these indices among the six different geopolitical zones and 37 individual states including the Federal Capital Territory were compared with the variation indicated by infection prevalence alone. Results: Among the six major geopolitical zones, only one had significantly higher asexual parasite prevalence than others, but parasite densities within infected children revealed more significant variation among the different zones. Comparing results for 2021 with previous data from 2018, one zone showed lower asexual parasite prevalence and two had lower sexual parasite prevalence, but three had higher asexual parasite densities in infected children. Variation in parasite densities among individual states also highlighted significant geographical and temporal differences, extending the detection of heterogeneity within each geopolitical zone. Overall trends were driven by the predominant parasite species Plasmodium falciparum as prevalence and density of the other species were much lower. Conclusions: Findings indicate that understanding complex patterns of geographical and temporal variation is enhanced by including asexual parasite density measurement, providing opportunities for more precise targeting of malaria control within high burden countries.

Aedes albopictus (Skuse), the Asian tiger mosquito, is a highly competent arboviral vector whose range has expanded substantially across the United States over the past four decades. Despite predictive models placing Nebraska within the species' climatically suitable range, its establishment status in the state has remained poorly characterized. Here, we report results from a nine-year mosquito surveillance program (2017-2025) conducted across 44 Nebraska counties in collaboration with the Nebraska Department of Health and Human Services. Ae. albopictus was detected in five counties, with sustained, annually increasing populations documented in Richardson, Douglas, and Lancaster counties. Richardson County recorded continuous detections during 2017-2025, with proportional representation rising to 60.50% of collected mosquitoes by 2025. In Douglas and Lancaster counties, temporal advancement of first seasonal detection in 2024 and 2025 provide evidence consistent with successful overwintering rather than annual reintroduction. A cumulative degree-day model predicted adult emergence in mid-May across all county-year combinations, consistently preceding trap deployment by two to seven weeks and revealing a systematic early-season surveillance gap. Generalized linear mixed-effects models indicated that trap-level detection persistence, rather than urban location, was the primary predictor of yearly Ae. albopictus positivity, suggesting that current invasion dynamics are driven by focal source populations. These findings provide strong evidence for the establishment of Ae. albopictus in eastern Nebraska and highlight the need for earlier seasonal surveillance and standardized criteria to define establishment in northward-expanding vector populations.

Tick-borne disease risk reflects the combined influence of vector abundance, pathogen prevalence, human exposure, and seasonal activity, yet these components are rarely integrated at the county level. We developed species-specific ecological risk scores for three medically important tick species (Acari: Ixodidae): Amblyomma americanum (L.), Dermacentor variabilis (Say), and Ixodes scapularis Say, across all 102 Illinois counties using data from 2019 to 2022. County-level predicted tick abundance and pathogen prevalence were scaled and combined using equal weights to generate primary vector-level risk scores. Robustness to the equal-weight assumption was evaluated by systematically varying the relative weights assigned to abundance and pathogen prevalence, while a separate sensitivity analysis incorporated reported tick-bite incidence where available. Associations with human disease were evaluated using negative binomial regression of tick-borne disease case counts on the corresponding risk scores, with county population included as an offset. Monthly phenology indicators were constructed by integrating human disease cases, reported tick bites, and sampled tick abundance and were evaluated in relation to temperature and precipitation. Seasonal risk was estimated by combining county-level vector risk with species-specific monthly phenology, generating monthly risk surfaces that were deployed through an interactive R Shiny application. Higher risk scores were significantly associated with greater disease case rates for each tick species. County rankings were highly stable under moderate changes in abundance and prevalence weighting. Seasonal activity differed among species, with A. americanum and D. variabilis showing concentrated warm-season risk and I. scapularis exhibiting a broader seasonal profile. These county-level seasonal risk maps identify where and when relative tick-borne disease risk is elevated in Illinois, supporting targeted prevention, surveillance, and clinical awareness.

In sub-Saharan Africa, human and animal health is threatened by African trypanosomoses. These diseases are caused by trypanosomes that are transmitted primarily by tsetse flies. Vector control remains one of the most effective strategies for reducing disease transmission, but requires a minimum level of knowledge of the population biology, ecology and dispersal patterns of the targeted vectors. In this respect, population genetic approaches using appropriate polymorphic genetic markers can provide valuable tools to inform and optimize control strategies. Senegal is currently engaged in a national tsetse control programme and has been identified as a study country within a European Union-funded research initiative, COMBAT (controlling and progressively minimizing the burden of animal trypanosomosis). Baseline entomological studies are currently underway in the Sine Saloum (Southern Senegal). This preliminary study aimed to characterize the population genetic structure and connectivity of tsetse fly species present in Southern Senegal, Glossina palpalis gambiensis and G. morsitans submorsitans, in order to assess their population sizes (geographically and demographically), population densities and dispersal capacities. The two species exhibited markedly contrasting population structures. The first, G. p. gambiensis, displayed an isolation by distance with rather dense subpopulations exchanging immigrants at short distances (1.6 km/generation) and continuously from Sine-Saloum to Casamance, in line with the apparent continuity of the mangrove network found along this coast. In contrast, G. m. submorsitans presented a relatively dense population over a 75 km wide area, fragmented into sparsely distributed, very dense and interconnected pockets. These findings indicate that G. p. gambiensis likely constitutes a large metapopulation comprising 3266 effective individuals on average (and up to 7765), whereas G. m. submorsitans appeared as a single and large population, scattered in small pockets that could be readily replenished by immigrants from distant areas in case of control. These results suggest that elimination is not a realistic option for any of these two populations. Alternatively, localized integrated pest management is likely to be the most effective approach for controlling the negative effects of these biting flies on domestic animals, by reducing trypanosome transmission. However, further entomological investigations and the use of more informative genetic markers are needed to obtain a more precise understanding of the epidemiological processes involved.

Brucellosis is a globally distributed and widely under-appreciated zoonotic bacterial disease that causes infertility and abortion in livestock and febrile illness in humans, sometimes with debilitating sequelae. Brucellosis incidence estimates typically focus on acute presentations and range from 50 to 100 per 100,000 people per year for endemic settings, showing marked variation within and between countries. Estimating brucellosis incidence in low-resource settings is complicated by lack of access to and utilisation of health care and high-quality diagnostic testing for many people in rural communities. To estimate brucellosis incidence in a pastoralist population in northern Tanzania, we developed a Bayesian model that integrates multiple data sources including diagnostic test results from a hospital-based prevalence study performed in 2016-2017, test sensitivity and specificity, and data from a community-based healthcare utilisation survey in 2019-2020. We show that this population experienced a high incidence of brucellosis with wide uncertainty, with estimates of 387.6 (95% HPDI: 103.3 - 903.5) illnesses per 100,000 people per year for the total population, 199.7 (95% HPDI: 16.2 - 584.6) for individuals aged >15 years, and 632.4 (95% HPDI: 180.1 - 1379.4) for children aged [&le;]15 years. These incidence estimates were among the highest in the world to date. The wide density intervals for these incidence estimates reflect uncertainty in the underlying parameter values used. Sensitivity analyses show that healthcare utilisation influenced incidence estimates the most. This result indicates that accounting for low levels of healthcare utilisation is essential to avoid under-estimating disease incidence. Our findings illustrate that brucellosis is a frequent cause of illness in this population. Increased access to treatment, prevention, and accurate diagnostic testing would greatly improve understanding of brucellosis epidemiology and the health of many people living in similar at-risk communities.

BACKGROUND: Indigenous tribes face a disproportionately high tuberculosis (TB) burden due to deep-rooted socioeconomic disadvantage, highlighting the need for strengthened, culturally sensitive control strategies. METHODS: We conducted a 21-year retrospective study (2005-2025) among tribal and neighboring non-tribal populations attending a tribal-serving hospital in Karnataka. Pre-Nikshay data were transcribed from paper registers, and post-Nikshay data were obtained from the digital system. We assessed negative binomial interrupted time-series regression model, data completeness, TB risk factors, and used multivariable logistic regression to identify determinants of poor treatment outcomes and household contact screening yield. RESULTS: We analyzed 1,512 TB cases (tribal = 1,021; non-tribal = 491). TB detection increased significantly over time, with a steeper rise among tribal populations (p<0.001). Nikshay implementation significantly improved data completeness (Wilcoxon W = 9900, p<0.001). Among tribal patients, males had higher odds of poor treatment outcome (aOR 2.81, 95% CI 1.70- 4.85; p<0.001). Diabetes (aOR 2.10, 95% CI 1.05- 4.03; p=0.029) was independently associated with poor treatment outcome. Among 503 index cases, 1,535 household contacts were identified and 1,161 (75.6%) screened; coverage was lower among tribal contacts (69.8% vs 87.2%; p<0.001). CONCLUSIONS: Nikshay strengthened TB surveillance and improved assessment of TB burden and risk factors in tribal communities.

Background Schistosomiasis is a parasitic disease caused by flatworms known as schistosomes. The infection cycle starts when people shed eggs through the stool or the urine. Larva infects freshwater snails to later infect humans through the skin during water based activities. Schistosomiasis is commonly associated with rural areas. In this study, we wanted to see if the schistosomiasis distribution is different in rural and urban areas, along with potential risk factors associated with schistosomiasis distribution. Methodology Fresh urine samples were collected from 1,699 school-aged children (5 - 15 years old) in urban and rural sites in the Kimpese health district. Prevalence of haematobium and mansoni schistosomiasis was determined using, respectively, the urine sedimentation and the Point-of-Care Circulating Cathodic Antigen test with a quantitative estimate of infection intensity obtained with an RDT-Reader. Collected risk factors were tested for association with schistosomiasis infection and its intensity. Results The overall prevalence of schistosomiasis found in urban and rural areas was 75% and 82% respectively, with higher prevalence of S. mansoni in rural schools, and higher S. haematobium prevalence in urban schools. The difference in total prevalence between schools in urban and rural areas was significant, X2 (1, N = 1699) = 13.03, p = .0003. S. mansoni intensity of infection was also higher in rural children (mean = 162 mV) compared to those in urban areas (mean = 76 mV) (p < 2e-16). Male gender, washing dishes in the river, and swimming were associated with schistosomiasis in urban areas. Age, Springs, and rivers were significant factors in rural sites. Age, river, and washing dishes in the river were factors associated with the intensity of infection. Conclusion Our results showed very high prevalence in both rural and urban areas, which implies that control programs should consider them with the same interest and also revise control strategies.