PLoS Neglected Tropical Diseases[JOURNAL]
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200 papers
Factors affecting detection and quantification of Schistosoma haematobium eggs in pooled urine samples.
Degarege A, Levecke B, Bilder CR … +6 more , Brett-Major DM, Animut A, Negash Y, Broadhurst MJ, Michaud TL, Erko B
PLoS Negl Trop Dis · 2026 Jun · PMID 42224359 · Full text
BACKGROUND: Building on our previous work showing that pooled urine testing can rapidly detect Schistosoma haematobium infections but has limited sensitivity in low-intensity settings or with large pool sizes, this study...
BACKGROUND: Building on our previous work showing that pooled urine testing can rapidly detect Schistosoma haematobium infections but has limited sensitivity in low-intensity settings or with large pool sizes, this study evaluated how urine volume, pool size, infection intensity, and diagnostic method affect the detection and quantification of S. haematobium eggs in pooled samples. METHODS: Between July 2022 and April 2023, 2,134 urine samples from school-age children living in three regional states of Ethiopia were individually examined by deploying urine filtration microscopy (UFM). Subsequently, 5, 10, 20 and 40 individual samples were strategically pooled and examined by deploying UFM and Fluke Catcher (FC) and varying volumes of urine (10, 20 and 30 mL). RESULTS: UFM was significantly more sensitive than FC for detecting S. haematobium eggs in pooled urine samples ([Formula: see text] =0.83, p < 0.001). There were significant interactions between the mean log of urine egg count (UEC) and volume of urine ([Formula: see text] =0.01, p = 0.021) or pool size ([Formula: see text] =-0.02, p = 0.007) for detecting S. haematobium eggs in pooled samples. The odds of detecting eggs in pooled samples in which the mean UEC of individual samples equaled 10 eggs/mL were 0.78 (95% CI:0.67-0.90) and 0.60 (95% CI:0.51-0.76) times lower when 10 mL rather than 20 mL and 30 mL was examined, respectively. There was a moderate or strong positive correlation between the mean egg count of pooled samples and the average egg count of the individual samples making the pools when pool sizes were 5, 10 or 20 (r ≥ 0.5). CONCLUSIONS: The diagnostic sensitivity of pooled testing for diagnosing S. haematobium infection is affected by a complex interplay between the pool size, the volume of urine examined, the mean UEC and the diagnostic method. The sensitivity of the pooled testing strategy may increase with larger urine volumes, higher infection intensity, and when UFM (rather than FC) is used for testing. However, sensitivity could decrease as the pool size increases. Use of UFM, larger urine volumes and smaller to moderate pool sizes could improve detection of S. haematobium infection in surveillance and mass deworming programs in low-intensity settings.
Performance of fecal inflammatory biomarkers to identify watery shigellosis: Findings from the Enterics for Global Health (EFGH) Shigella surveillance study.
Ogwel B, Khanam F, Badji H … +33 more , Charles M, Qureshi S, Horne B, Brennhofer SA, Platts-Mills JA, Sears K, Tennant S, Kim S, Omore R, Awuor AO, Okonji C, Iqbal J, Ahmed N, Hussain Z, Qadri F, Raz SMAA, Bhuiyan ES, Yori PP, Olortegui MP, Kosek MN, Jallow SJ, Ceesay BE, Conteh B, Nyirenda AK, Munthali V, Lefu C, Bhuiyan TR, Munga S, Hossain MJ, Cornick J, Qamar FN, Benkeser D, Rogawski McQuade ET
PLoS Negl Trop Dis · 2026 Jun · PMID 42224289 · Full text
BACKGROUND: Current syndromic guidelines for diarrhea treatment miss watery Shigella cases, leading to undertreatment of children who may benefit. Incorporating fecal inflammatory biomarkers into diagnosis may improve ca...
BACKGROUND: Current syndromic guidelines for diarrhea treatment miss watery Shigella cases, leading to undertreatment of children who may benefit. Incorporating fecal inflammatory biomarkers into diagnosis may improve case identification. METHODS: We conducted an ancillary analysis using samples from six sites (The Gambia, Kenya, Malawi, Bangladesh, Pakistan, and Peru) from the Enterics for Global Health (EFGH)-Shigella surveillance study, a facility-based hybrid study of children aged 6-35 months with diarrhea. Four fecal biomarkers were quantified by enzyme-linked immunosorbent assays at enrollment: myeloperoxidase, calprotectin, neutrophil gelatinase-associated lipocalin (lipocalin-2), and hemoglobin. An ensemble model with leave-one-site-out cross-validation was used to predict watery shigellosis, incorporating biomarkers and nine clinical and socio-economic predictors. We compared the predictive performance of the algorithm using: a) all predictors (including biomarkers); b) all non-biomarker predictors; c) all predictors (with selected biomarkers). RESULTS: Between June 2022 and August 2024, a total of 4,191/9,476 (44.2%) children presented with watery diarrhea (non-bloody) and had their whole stool tested for the biomarkers and 4,083 stool samples or rectal swabs were tested by qPCR; 735 (18.0%) had Shigella-attributable diarrhea by qPCR. The full model incorporating all 13 predictors achieved an area under the curve (AUC) of 0.75 [95% CI: 0.67-0.78], with a sensitivity of 0.67 and specificity of 0.75. Excluding biomarkers reduced model performance by 8% (AUC 0.67, 95% CI: 0.61-0.70). Adding hemoglobin alone improved the model's discriminatory ability by 7%, while further adding myeloperoxidase had marginal contribution (1%), and lipocalin-2 (0%) and calprotectin none (0%). CONCLUSION: Fecal hemoglobin substantially improved prediction scores for watery shigellosis. Consequently, implementation of point-of-care assays for hemoglobin could improve clinical diagnosis in these settings and inform appropriate antibiotic treatment.
High infection risk of intestinal helminths despite WASH interventions: A cross-sectional study in Khammouane province, Lao PDR.
Khounvisith V, Virachith S, Innoula N … +7 more , Vongphachanh B, Khenkha L, Hattendorf J, Sayasone S, Hübschen JM, Black AP, Odermatt P
PLoS Negl Trop Dis · 2026 Jun · PMID 42224275 · Full text
BACKGROUND: Despite the widespread implementation of water, sanitation and hygiene (WASH) program over the last two decades, Lao People's Democratic Republic (Lao PDR) remains highly endemic for intestinal helminth infec...
BACKGROUND: Despite the widespread implementation of water, sanitation and hygiene (WASH) program over the last two decades, Lao People's Democratic Republic (Lao PDR) remains highly endemic for intestinal helminth infections. We assessed the intestinal helminth infections burden and the link with WASH levels in an area with WASH interventions. METHOD: A cross-sectional study was conducted across 81 villages in Khammouane province, Lao PDR, where WASH interventions were implemented. Villages and 30 participants (aged 18-87 years) per village were randomly selected. Demographics, individual and household data, including WASH-related factors were collected. Stool samples were examined for intestinal helminth infections using formalin-ethyl acetate concentration technique (FECT). Logistic regression analysis was performed to identify risks associated with intestinal helminth infections. RESULTS: A total of 1530 participants were included. Multi-helminth species infection was very common, e.g., 30.1% had a double infection. Opisthorchis viverrini was most prevalent (56.9%), followed by hookworm (54.7%), minute intestinal flukes (22.7%), and Trichostrongylus spp. (10.7%). Overall, 56.1% and 44.4% had access to safely management water services and sanitation facilities, respectively, and 17.7% practiced open defecation. Improved WASH levels were not associated with reduced intestinal helminth infections. District of residence, age, gender and raw food consumption predicted helminth infections. E.g., O. viverrini infection was associated with residency in Mahaxai district (Mahaxai, aOR = 14.0; 95% CI = 9.5-20.6; p < 0.001 and Bulapha, aOR = 3.0; 95% CI = 2.0-4.4; p < 0.001). CONCLUSION: Our findings indicate a high intestinal helminth infections burden in this province, with several risk factors such as location, age, gender and consumption of raw food predicting helminth infection. Improved WASH levels are not associated with reduces prevalence of intestinal helminth infection in this cross-sectional study.
Spatiotemporal dynamics and serosurveillance landscape of brucellosis at the human-animal interface in the Chinese Southwest: A retrospective study.
Yang Q, Zhang N, Shi Y … +4 more , Yuan M, Zheng C, Li Z, Liu Z
PLoS Negl Trop Dis · 2026 May · PMID 42213764 · Full text
INTRODUCTION: Human brucellosis is re-emerging in the Chinese Southwest, and its epidemic characteristics remain unclear. METHODOLOGY: Descriptive epidemiology, Joinpoint regression, spatial autocorrelation, serological...
INTRODUCTION: Human brucellosis is re-emerging in the Chinese Southwest, and its epidemic characteristics remain unclear. METHODOLOGY: Descriptive epidemiology, Joinpoint regression, spatial autocorrelation, serological surveillance and pathogen analysis were adopted to clarify the epidemiological evolution of the disease. RESULTS: Between 2004 and 2024, 9,822 brucellosis cases occurred, dominated by 7,270 cases in Yunnan. The epidemic showed a persistent upward trend (AAPC ≥5.28, P < 0.05), and 51 cities/prefectures were identified with statistically significant increse (AAPC ≥ 9.30, P < 0.05). Serological surveillance of 36,459 individuals revealed a seropositivity rate of 2.13% (95%CI, 2.00%, 2.26%), identifying 1,831 new cases. Sheep/goats seropositivity at 1.02% (95%CI, 0.97%, 1.06%) and cattle at 0.45% (95%CI, 0.42%, 0.48%). Sustained elevated human incidence was validated by serological evidence, and seroprevalence trends in sheep/goats aligned closely with human epidemic dynamics. Human brucellosis has evolved from random to significantly geographically and spatial aggregated, spreading continuously with intensified clustering in central-eastern Yunnan, the Sichuan basin and Tibet's Ngari-Qamdo axis, highlighting these as priority control zones. Human brucellosis has transitioned from sporadic to locally endemic, with phased progression and increasing geographical clustering recently. Human brucellosis in the Chinese Southwest is characterized by the persistent dominance of B. melitensis bv. 3, primarily represented by the co-circulating MLVA-11 genotypes GT116 and GT125, which form a stable, widely disseminated lineage across the region. CONCLUSION: From the re-emergence to persistent endemicity of human brucellosis in study area, the extensive distribution of B. melitensis with unique genotyping reveals a stable zoonotic cycle that requires coordinated regional control.
From invisibility to political power: Policy lessons from a decade of Brazil's Social Forum for Infectious and Neglected Diseases.
Pinheiro EDS, Araújo CEL, Cunha ESM … +5 more , Rocha AMD, Lopes Nunes Galvão D, Souza EA, da Silva MPCAM, Ramos AN
PLoS Negl Trop Dis · 2026 May · PMID 42213745 · Full text
Neglected tropical diseases (NTDs) cluster among populations living in poverty and facing overlapping social, environmental, and political vulnerabilities. Brazil has one of the most significant NTD burdens in the Americ...
Neglected tropical diseases (NTDs) cluster among populations living in poverty and facing overlapping social, environmental, and political vulnerabilities. Brazil has one of the most significant NTD burdens in the Americas, yet affected populations have historically had limited influence on national health agendas. In 2016, amid democratic backsliding and fiscal austerity, civil society, researchers, and affected communities created the Brazilian Social Forum for Combating Infectious and Neglected Diseases (FSBEDIN) to strengthen political participation. Using documentary analysis of Forum letters (2016-2025), institutional records, and participant observation, we show how FSBEDIN evolved from a crisis-driven initiative into a recognized actor in Brazilian health governance. The Forum has linked disease-specific movements, expanded the presence of affected leaders in health councils and technical committees, supported leadership training, and helped catalyze the creation of a National Movement for Neglected Diseases. It also advances an agenda that connects NTD control to democracy, social justice, and pharmaceutical sovereignty. We argue that FSBEDIN offers practical lessons for implementing the World Health Assembly resolution on social participation and the WHO 2030 NTD roadmap. We propose policy measures for governments, the WHO, and development partners to institutionalize meaningful involvement of affected communities as a non-negotiable standard for NTD programs.
Unravelling the distribution of vectors of major vector-borne diseases in Koshi Province of Nepal: A concern of expansion in diverse geo-ecological and climatic regions.
Roy L, Uranw S, Pote Shrestha RR
PLoS Negl Trop Dis · 2026 May · PMID 42213710 · Full text
BACKGROUND: Vector-borne diseases (VBDs), including malaria, visceral leishmaniasis, lymphatic filariasis, Japanese encephalitis, and dengue, are major public health concerns and are either slated for elimination or proj...
BACKGROUND: Vector-borne diseases (VBDs), including malaria, visceral leishmaniasis, lymphatic filariasis, Japanese encephalitis, and dengue, are major public health concerns and are either slated for elimination or projected for control in Nepal. One of the major challenges in controlling these VBDs is halting their emergence and expansion in diverse geo-ecological and climatic regions. In this study, we collected vectors of major VBDs to assess their distribution, diversity, and associations with ecological variations and to provide an updated understanding of the current situation. METHODOLOGY/PRINCIPAL FINDINGS: A descriptive cross-sectional survey was conducted in five districts of Koshi Province, eastern Nepal, during May and June 2023 to collect vectors across three distinct geo-ecological and climatic regions: mountains, hills, and lowlands, situated at altitudes ranging from 98 to 1,274 meters. Adult mosquitoes and sand flies were captured using CDC miniature light traps, BG-Sentinel traps, and manual aspirators. We fitted generalized linear models (GLM) with a negative binomial distribution to assess the association between vector abundance and geo-ecological and climatic variables for two vector species (Culex quinquefasciatus and Phlebotomus argentipes). We found the malaria vector, Anopheles annularis, the lymphatic filariasis vector, Cx. quinquefasciatus and the visceral leishmaniasis vector, Ph. argentipes, across all three geo-ecological regions. Other vectors of the malaria parasite, An. pseudowillmori and An. willmori, and Japanese encephalitis vector Cx. tritaeniorhynchus were recorded only in hilly districts. Mean temperature and rainfall had a positive effect on Cx. quinquefasciatus density, but a deleterious effect on Ph. argentipes. Culex quinquefasciatus and Ph. argentipes were captured in higher abundance at the household level in the hills (IRR = 1.23 and IRR = 13.00, respectively) and mountains (IRR = 1.96 and IRR = 4.00, respectively) compared with the lowlands. CONCLUSION: Two major vectors, Cx. quinquefasciatus and Ph. argentipes were indiscriminately present in all geo-ecological regions. Climatic variables seemed conducive to vector survival, distribution, and growth across diverse altitudes from the lowlands to the high hills and mountains. Our findings highlight the need for the VBDs control programme to implement regular monitoring, strengthen existing surveillance systems, and support evidence-based planning and implementation of vector control interventions across wider geo-ecological regions to prevent disease transmission.
Clinical characteristics, treatment outcomes, and predictors of early mortality in Vibrio vulnificus infection in Eastern Thailand: A 6.5-year multicenter cohort study.
Hemapanpairoa J, Wongduang S, Wongwian T … +1 more , Santimaleeworagun W
PLoS Negl Trop Dis · 2026 May · PMID 42213704 · Full text
Vibrio vulnificus is a rapidly progressive, life-threatening pathogen endemic to coastal environments, yet clinical data from Southeast Asia remain limited despite substantial environmental contamination. We conducted a...
Vibrio vulnificus is a rapidly progressive, life-threatening pathogen endemic to coastal environments, yet clinical data from Southeast Asia remain limited despite substantial environmental contamination. We conducted a 6.5-year multicenter retrospective cohort study at two tertiary-care hospitals in Eastern Thailand to describe clinical characteristics, antimicrobial susceptibility, treatment practices, and factors associated with early mortality among adults with culture-confirmed V. vulnificus infection. Forty-nine patients were identified, most of whom presented with severe illness; 83.7% had bacteremia, 61.2% required mechanical ventilation, and 75.5% required vasopressor support. Skin and soft tissue infection was the most common syndrome, with necrotizing soft-tissue infection accounting for approximately two-thirds of cases. Antimicrobial susceptibility was uniformly high for fluoroquinolones, carbapenems, and third-generation cephalosporins, although susceptibility to doxycycline was unavailable. Despite high rates of empirical antimicrobial therapy (91.8%), mortality remained substantially high: 42.9% died within 48 hours, and 7-day mortality reached 49.0%. In multivariable analysis, elevated serum lactate and lack of surgical treatment were associated with early mortality, while chronic alcohol use and vasopressor requirement showed nonsignificant trends toward increased mortality. These findings highlight the fulminant nature of V. vulnificus infection and the narrow therapeutic window for effective intervention. In settings where necrotizing soft-tissue infection is common and patients present with advanced disease, early recognition, aggressive resuscitation, timely surgical management, and prompt initiation of antimicrobial therapy remain essential. This study provides region-specific epidemiologic and clinical insights that may inform clinical management and public health strategies in coastal communities at risk.
Leishmania major virulence attenuation in vitro: An old conundrum revisited in the omics era.
Gerasimov ES, Záhonová K, Ishemgulova A … +7 more , Novozhilova TS, Mishra SK, Kraeva N, Sádlová J, Volf P, Zimmer SL, Yurchenko V
PLoS Negl Trop Dis · 2026 May · PMID 42213660 · Full text
BACKGROUND: It has been known for decades that long-term cultivation of Leishmania in vitro frequently leads to a loss of virulence, which is attributed to the selective advantage of avirulent subpopulations that outgrow...
BACKGROUND: It has been known for decades that long-term cultivation of Leishmania in vitro frequently leads to a loss of virulence, which is attributed to the selective advantage of avirulent subpopulations that outgrow the virulent ones. In the case of L. major, avirulent parasites retained the ability, albeit reduced, to develop nearly normally in sand fly vectors; however, they could not induce lesions in BALB/c mice. Residual persistence in the inguinal lymph nodes permitted re-isolation and subsequent additional murine passages of these flagellates. While a parasite line obtained after five consecutive passages of avirulent Leishmania in mice was not fully restored to virulence, this line, as well avirulent parasites passaged five times through the sand fly vector Phlebotomus duboscqi developed very efficiently in sand flies. MATERIALS AND METHODS: Leishmania major cell lines with differing capacities for host survival were studied using genomic and transcriptomic approaches. Specifically, we focused on genetic mutations, gene copy number variation, differential gene expression, and differences in kinetoplast DNA, including RNA editing and minicircle repertoire. RESULTS: While genetic mutations contributed little to differences in host survival, changes in the gene copy number were correlated with alterations to avirulence. Survival capacity strongly correlated with gene expression patterns. Avirulent parasites showed increased abundance of ribosomal and translation-related transcripts compared with lines capable of persistent survival, suggesting selective pressure to restrict translational capacity in hosts. Most interestingly, the relative abundance of kinetoplast DNA minicircle classes, encoding guide RNAs, was altered during culture but reverted to the virulent pattern following mouse and sand fly passage. CONCLUSIONS: Our results indicate that at the DNA and mRNA levels, L. major survival in the insect vector or mammalian host is primarily driven by adaptive regulation of gene expression rather than fixed genetic changes. Modulation of translational capacity and host-specific expression programs appear central to parasite persistence, highlighting flexible cellular strategies that support survival in natural transmission cycles.
Cholera in Africa: Current trends, challenges, and control towards elimination strategies.
Muvunyi CM, Siddig EE, Ali ETO … +5 more , Iradukunda PG, Gashema P, de Dieu Harelimana J, Mazaba ML, Kaseya J
PLoS Negl Trop Dis · 2026 May · PMID 42207744 · Full text
Cholera remains a substantial public health challenge in Africa, despite the availability of effective vaccines, treatment, and preventive measures. Systemic issues such as inadequate water, sanitation, and hygiene (WASH...
Cholera remains a substantial public health challenge in Africa, despite the availability of effective vaccines, treatment, and preventive measures. Systemic issues such as inadequate water, sanitation, and hygiene (WASH) infrastructure, weak disease surveillance, socio-economic disparities, and ongoing conflict and instability drive its persistence. This article provides the current situation of cholera in Africa, highlighting systemic barriers to control, including data deficiencies, limited diagnostic capacity, and infrastructural deficits. Crucially, we underline the importance of integrated strategies encompassing enhanced surveillance, targeted vaccination campaigns, WASH improvements, and addressing social determinants like poverty and displacement. Strengthening multisectoral and multidisciplinary collaborations and leveraging technological innovations are vital steps toward eliminating cholera in Africa. Achieving this goal requires sustained political commitment, increased resource mobilization, and context-specific solutions tailored to the diverse challenges faced by vulnerable communities.
Global burden, projections, and causal factors of maternal sepsis and other maternal infections: A comprehensive epidemiological and mendelian randomization study.
Jiang A, Duan S, Wu S … +2 more , Yu W, Liang X
PLoS Negl Trop Dis · 2026 May · PMID 42201989 · Full text
BACKGROUND: Maternal sepsis and other maternal infections (MSMI) remain major contributors to global maternal morbidity and mortality. However, the integration of epidemiological trends with causal inference evidence rem...
BACKGROUND: Maternal sepsis and other maternal infections (MSMI) remain major contributors to global maternal morbidity and mortality. However, the integration of epidemiological trends with causal inference evidence remains limited. METHODS: Using data from the Global Burden of Disease (GBD) 2021 study, we assessed temporal trends in MSMI burden from 1990 to 2021 and projected future patterns using ARIMA and Bayesian age-period-cohort (BAPC) models. In parallel, we conducted a two-sample multivariable Mendelian randomization (MVMR) analysis to evaluate the causal effects of inflammatory biomarkers and related factors on MSMI risk. RESULTS: Although age-standardized rates declined globally, absolute case numbers increased in low-SDI regions, largely driven by population growth. Forecasting results differed between ARIMA and BAPC models, reflecting distinct underlying assumptions regarding temporal dynamics. MVMR analysis identified inflammatory biomarkers, including CRP, IL-13, IL-10, RANTES, and NT-proBNP, as key causal factors associated with MSMI. CONCLUSIONS: This study provides the first integrated framework combining global disease burden analysis with multivariable MR. By linking population-level trends with causal inference, our findings offer dual evidence to support targeted prevention strategies and advance precision public health interventions for MSMI.
Crimean-congo haemorrhagic fever virus circulates within broad ecological networks of ticks and vertebrates.
Estrada-Peña A, Carnell O, Wijburg SR … +2 more , Holding M, Sprong H
PLoS Negl Trop Dis · 2026 May · PMID 42201981 · Full text
We produced spatial datasets of the known distribution of Orthonairovirus haemorrhagiae (formerly Crimean-Congo haemorrhagic fever virus, CCHFV) by compiling human cases, virus isolations, and serological data from human...
We produced spatial datasets of the known distribution of Orthonairovirus haemorrhagiae (formerly Crimean-Congo haemorrhagic fever virus, CCHFV) by compiling human cases, virus isolations, and serological data from humans and animals, spanning from Europe to southern Africa, with the aim of virus range modelling. Models based solely on climatic variables produced unrealistic and overly extensive predictions, overestimating suitability in northern Europe and confirming that climate alone poorly explains CCHFV range. Approaches using only tick species distributions underperformed in many parts of Africa, reflecting the complexity of vector-host interactions and the absence of a strict tick-virus association. The integration of human-biting tick distributions, livestock density, and chorotypes yielded the most robust results, accurately capturing over 90% of known occurrences, by identifying vertebrate assemblages most likely to amplify the virus while reducing the number of explanatory variables. Chorotypes, representing clusters of co-occurring hosts, enhanced model performance and improved the delineation of both the Palearctic and African ranges limits of the virus. Our results support a generalist epidemiological model in which multiple tick species, together with a broad range of vertebrate hosts, sustain CCHFV circulation. This ecological flexibility, rather than strict vector specificity, likely explains the CCHFV wide biogeographical range and occasional lineage expansions across continents. This study provides the most comprehensive assessment to date of the determinants of the distribution of CCHFV. Although gaps remain, this study demonstrates that coupling abiotic and biotic predictors provides a more accurate and ecologically meaningful understanding of CCHFV distribution.
Interactions between mosquito genetic background and Wolbachia strain affect dengue virus blocking and fitness in South American populations of Aedes aegypti.
Ser SL, Dennington NL, Engler HI … +7 more , Harris ML, Jones MJ, Avila FW, Caragata EP, Hoffmann AA, Maciel de Freitas R, McGraw EA
PLoS Negl Trop Dis · 2026 May · PMID 42201949 · Full text
The mosquito Aedes aegypti is the primary vector of dengue virus, and the release of mosquitoes infected with the bacterium Wolbachia is an increasingly used strategy to reduce dengue transmission. This approach relies o...
The mosquito Aedes aegypti is the primary vector of dengue virus, and the release of mosquitoes infected with the bacterium Wolbachia is an increasingly used strategy to reduce dengue transmission. This approach relies on Wolbachia's ability to suppress virus replication within the mosquito, but the effectiveness of virus suppression and the associated fitness costs may depend on interactions among mosquito genetic background, Wolbachia strain, and dengue virus type. Here, we examined these interactions using mosquito populations from Brazil, Paraguay, and Peru infected with two Wolbachia strains, wMelM and wAlbB, and exposed to dengue virus serotype 1 or serotype 2. We measured dengue virus infection in transmission-relevant tissues and quantified mosquito survival, development, and reproduction under controlled laboratory conditions. Wolbachia infection reduced dengue virus infection overall, but the strength of virus suppression varied among mosquito populations, with the strongest blocking observed in Brazilian mosquitoes and the weakest in Peruvian mosquitoes. Across all populations, the wMelM strain consistently produced stronger dengue virus suppression than wAlbB, whereas mosquitoes infected with wAlbB generally exhibited higher fitness, with fitness effects varying among mosquito populations and life-history traits. Together, these results show that genetic interactions among the mosquito, Wolbachia, and dengue virus shape both virus blocking and mosquito fitness, highlighting trade-offs that may influence the establishment and long-term effectiveness of Wolbachia-based dengue control programs.
Feasibility study of an AI-powered mobile app to support cutaneous leishmaniasis diagnosis in the Brazilian Amazon.
Okita KL, Pinheiro TB, Oliveira-Ciabati L … +10 more , Alves BDS, Bonett PLG, Fragoso EL, Rivero-Zavala EJ, Fernandes AJ, Souza GC, Sales JEDS, Guerra MDGVB, Guerra JAO, Carvalho I
PLoS Negl Trop Dis · 2026 May · PMID 42201945 · Full text
BACKGROUND: Cutaneous leishmaniasis (CL) remains a major public health challenge, especially in Brazil's Amazon, where environmental and economic pressures sustain transmission. Delayed diagnosis drives morbidity, stigma...
BACKGROUND: Cutaneous leishmaniasis (CL) remains a major public health challenge, especially in Brazil's Amazon, where environmental and economic pressures sustain transmission. Delayed diagnosis drives morbidity, stigma, and costs. Community health workers are pivotal yet under-equipped for early triage. Artificial intelligence, effective in dermatologic imaging, is underused for CL; feasible, offline clinical tools could accelerate referral and timely care. This study aimed to evaluate the feasibility of an AI-assisted tool for early CL triage in the Brazilian Amazon by: (i) developing an AI model for CL identification from clinical skin lesion images; (ii) integrating the model into an offline-optimized mobile application for resource-limited settings; and (iii) conducting initial, real-world clinical validation. METHODS: Exploratory, IRB-approved feasibility study. Retrospective images from Brazilian Amazon sites informed a two-stage AI pipeline (lesion segmentation+classification) integrated into an offline mobile app. Multicenter validation in ideal- and real-world scenarios. Primary metric AUC-ROC; secondary sensitivity/specificity. One-sided tests: AUC-ROC [Formula: see text]0.70; ideal-world sensitivity [Formula: see text]0.75. RESULTS: For the Classification Model, 64 images were assigned to the test set while 1,160 were used for training and validation (80:20 split), with DenseNet121 yielding the highest accuracy of 0.88. The full AI pipeline (Segmentation and Classification models) achieved an accuracy of 0.81, an F1-score of 0.80, an AUC-ROC of 0.90, and a sensitivity of 0.76. In the ideal-world analysis, sensitivity reached 0.92, the F1-score was 0.84, and specificity was 0.42. CONCLUSIONS: We demonstrate the feasibility of an offline, AI-assisted mobile tool to support triage and referral for cutaneous leishmaniasis in the Brazilian Amazon. Performance reflects preliminary, descriptive point estimates from an initial diagnostic accuracy assessment and should be interpreted with caution; the tool is not intended for standalone diagnosis. Next steps include prospectively powered clinical validation, usability refinements, and regulatory evaluation, including alignment with ANVISA requirements in Brazil. Overall, this work represents an initial step toward closing the gap in clinically supported diagnostic tools for neglected tropical diseases in resource-constrained settings.
Clinical outcomes associated with schistosome infection and alcohol use: A systematic scoping review.
Lyne B, Lang MM, Lewington S … +1 more , Chami GF
PLoS Negl Trop Dis · 2026 May · PMID 42201925 · Full text
BACKGROUND: Schistosomiasis and alcohol use are major, co-occurring risk factors for liver disease in low and middle-income countries. However, their interactions and shared disease outcomes remain poorly understood. MET...
BACKGROUND: Schistosomiasis and alcohol use are major, co-occurring risk factors for liver disease in low and middle-income countries. However, their interactions and shared disease outcomes remain poorly understood. METHODS: We conducted a scoping review to understand how schistosome infection and alcohol use influence author-defined health outcomes. A systematic search was carried out on 3 March 2025 using the following databases: PubMed (1946 - present), Embase (1974 - present), Web of Science (1964 - present), Global Index Medicus (1901 - present), and Global Health (1973 - present). Quality of studies was assessed descriptively by assessing bias and confounding. RESULTS: The search yielded 2358 articles, with 21 studies eligible for synthesis. Most studies (76.2%, 16/21) focused on current S. mansoni infection, and the same proportion treated alcohol use as a binary variable. The most frequently reported clinical outcomes were periportal fibrosis (42.9%, 9/21), and biomarkers (19%, 4/21), including serum iron markers. For hepatic outcomes, both synergistic and antagonistic pathways are plausible, while for iron-related outcomes, an antagonistic relationship was supported. Cross-sectional studies were most common (66.7%, 14/21), limiting the ability to make assessments on the temporal relationships between exposures and clinical outcomes. Selection bias was the most frequently reported source of bias (28.6%, 6/21), and only four (19%) studies reported both adjusted and unadjusted analyses, allowing for an assessment of confounding. CONCLUSIONS: Co-occurring schistosomiasis and alcohol use has been associated with more severe liver pathology, presenting a significant public health concern in endemic areas. Current literature focuses on schistosome-related pathology, where alcohol use acts as a modifying factor. Future research should prioritise longitudinal designs with standardised definitions of alcohol use to better understand interactions between these two exposures for liver outcomes.
The impact of elevation and population density on dengue incidence and force of infection across the Philippines: Implications for climate-adapted surveillance.
Sy AK, Biggs J, Chowdhury SK … +11 more , Quinones MA, Salazar FV, Jones-Warner W, Ashall J, Sucaldito MNL, Cutiongco-de la Paz E, Capeding MRZ, Padilla CD, Villanueva SYAM, Hibberd ML, Hafalla JCR
PLoS Negl Trop Dis · 2026 May · PMID 42189923 · Full text
Climate change is accelerating the geographical expansion of Aedes mosquito vectors, facilitating the emergence of arboviral diseases such as dengue in new regions. However, there is limited understanding of how environm...
Climate change is accelerating the geographical expansion of Aedes mosquito vectors, facilitating the emergence of arboviral diseases such as dengue in new regions. However, there is limited understanding of how environmental factors, such as temperature and population density, differentially influence key metrics of dengue transmission. This study investigates how elevation (a proxy for temperature) and population density affect dengue incidence and force of infection (FOI), both independently and dependently, across the Philippines, with implications for climate-adapted surveillance and control. We conducted a nationwide, cross-sectional survey across the Philippines (2013-2019), combining national dengue case data (N = 1,112,317) with antibody IgG seroprevalence data from a representative sample (N = 22,270). Dengue FOI (the predicted rate at which individuals become exposed to DENV annually) and incidence were estimated across elevation and population density strata using catalytic models. Regression analyses were used to assess interactions between geographic factors and the dengue FOI. Elevation and population density were associated with FOI, but not with reported dengue incidence, which varied unpredictably over space and time. Urban, low-elevation barangays had the highest FOI (13.2%), while rural and urban, high-elevation areas had lower FOI (<7.7%). These patterns held across years, island groups, and regions. A statistical interaction between elevation and population density on the dengue FOI improved model fit (p < 0.0053) and revealed population density is a driver of transmission intensity in low lying areas (<1200m) but not in high elevation areas (>1200m). Dengue burden in the Philippines is highest in low-lying, urban areas and significantly lower in high-elevation zones, irrespective of population density, where cooler temperatures prevail. FOI is a more reliable metric than incidence for understanding transmission dynamics and guiding interventions. Our findings highlight the need for geographically tailored control strategies, particularly as climate change alters environmental and demographic conditions.
High-resolution automated mapping of potential Aedes larval container habitats using drone imagery and supervised machine learning in Dar es Salaam, Tanzania.
Hahm M, Guthula VB, Chilaule R … +14 more , Gominski D, Limwagu A, Chaki E, Okumu F, Tingitana L, Hermund A, Tusting LS, Fensholt R, Riberio G, Knudsen JB, Mottelson J, Mlacha Y, Cameron M, Igel C
PLoS Negl Trop Dis · 2026 May · PMID 42189914 · Full text
Larval source management is a key strategy to control the spread of Aedes-borne viral diseases including dengue, Zika, chikungunya, and yellow fever. However, locating potential larval habitats through traditional field...
Larval source management is a key strategy to control the spread of Aedes-borne viral diseases including dengue, Zika, chikungunya, and yellow fever. However, locating potential larval habitats through traditional field methods is challenging and labor-intensive at scale. Here, we demonstrate a scalable, high-resolution drone imagery and supervised machine learning approach to map potential Aedes larval container habitats across Dar es Salaam, Tanzania, a dense urban environment with informal settlements. Local larval surveillance and existing literature confirm epidemiological relevance of buckets and jerry cans, tires, and water tanks as key potential habitats. Drone images revealed rooftop tires, a container type likely overlooked during ground surveillance. We trained a U-Net deep learning model on very-high-resolution drone imagery (3-5 cm resolution) which was manually annotated across 4.6 km2, and applied it to predict containers across 27.27 km2, spanning 20 neighborhoods. The model predicted over 135,000 containers with detection accuracies of 75% for water tanks, 72% for tires, and 54% for buckets. Bucket and tire densities were strongly and positively correlated with population density across neighborhoods, whereas water tank density was not, suggesting the distribution of these container types reflect distinct underlying drivers. This study reveals otherwise difficult-to-observe container types, highlights the abundance and spatial heterogeneity of potential Aedes larval habitats across Dar es Salaam, and demonstrates a scalable approach for improving detection of potential Aedes larval container habitats in a dense urban environment.
Monoclonal antibody-based immunohistochemistry reveals residual Taenia solium antigens in calcified granulomas from pigs with neurocysticercosis.
Toribio LM, Tello-Ccente LB, Arroyo G … +6 more , Verastegui MR, Gilman RH, Nash TE, Garcia HH, Bustos JA, on behalf the Cysticercosis Working Group in Peru [CWGP]
PLoS Negl Trop Dis · 2026 May · PMID 42189889 · Full text
BACKGROUND: Neurocysticercosis (NCC), a parasitic brain infection caused by Taenia solium larvae, remains a leading cause of preventable epilepsy globally. Although calcified brain lesions were formerly considered as the...
BACKGROUND: Neurocysticercosis (NCC), a parasitic brain infection caused by Taenia solium larvae, remains a leading cause of preventable epilepsy globally. Although calcified brain lesions were formerly considered as the quiescent end stage of NCC, they may act as epileptogenic foci. It has been suggested that parasitic antigens within calcified lesions may act as potential triggers of inflammation and subsequent seizure activity. In this study, we developed and optimized immunohistochemistry (IHC) assays employing anti-Taenia solium monoclonal antibodies (mAbs) to detect residual cyst antigens in calcified lesions in a porcine NCC model and assessed antigen persistence for up to 12 months after successful antiparasitic treatment. METHODS/PRINCIPAL FINDINGS: Six mAbs raised against T. solium whole cyst (TsW5, TsW8, and TsW12), vesicular fluid (TsV3 and TsV4), and excretory/secretory products (TsE1) were used for IHC assay development and tested in brain sections containing viable brain cysts from NCC pigs and uninfected tissue from controls to optimize assay conditions, blocking, primary and secondary antibody dilutions. Optimized assays were subsequently performed in selected calcified granulomas (n = 20) obtained from NCC-infected pigs sacrificed at 4, 8, and 12 months after antiparasitic treatment to identify residual cyst antigens as well as their localization and area of reactivity. We observed residual cyst antigens in 65-80% of calcified granulomas, with TsW8 and TsV3 showing the highest percentages of immunoreactivity. Antigen localization followed two patterns, one with antigens entirely located within the calcified lesions (TsW5, TsW8, TsW12, and Tsv4) and another with antigens located outside the cyst in the perilesional brain tissue (TsV3 and TsE1). Antigen detection and the extent of reactivity declined progressively after antiparasitic treatment but persisted at detectable immunoreactive areas in calcified granulomas up to month 12 months after treatment. CONCLUSIONS/SIGNIFICANCE: T. solium antigens remain detectable in calcified granulomas and in the perilesional tissue for up to 12 months after antiparasitic treatment in the pig model.
Expanded molecular evidence of soil-transmitted helminth and Schistosoma spp. infections in Myanmar schoolchildren: A qPCR update.
Aung E, Collinson N, Han KT … +15 more , Hlaing NN, Aye MM, Htun MW, Wai KT, Myat SM, Thwe TL, Tun A, Wangdi K, Li Y, Williams GM, Clements ACA, Nery SV, McManus DP, Gray DJ, Gordon CA
PLoS Negl Trop Dis · 2026 May · PMID 42189884 · Full text
Building on our previous report of high prevalence of soil-transmitted helminth (STH) infections among Myanmar schoolchildren (Aung et al., Infectious Diseases of Poverty, 2022), we conducted additional molecular screeni...
Building on our previous report of high prevalence of soil-transmitted helminth (STH) infections among Myanmar schoolchildren (Aung et al., Infectious Diseases of Poverty, 2022), we conducted additional molecular screening of archival stool samples from the same cohort in Phyu Township, Bago Region, to investigate additional helminth infections. We also report finding of other helminths by Kato-Katz in the previous study that were not previously published. Stool samples utilised in this study were collected in 2016 and the DNA extracted in 2017 and kept stored at -20°C until further molecular characterisation in this study in 2025. Using quantitative PCR (qPCR), we detected Schistosoma DNA in two of 264 samples, Strongyloides stercoralis DNA in twelve, and Ancylostoma ceylanicum in eleven. Although sequencing of the Schistosoma-positive samples was unsuccessful, the molecular evidence aligns with other recent reports suggesting emerging or cryptic transmission of schistosomiasis in Myanmar. The epidemiology of schistosomiasis in the region remains poorly defined, highlighting the need for targeted snail surveys, environmental DNA (eDNA) monitoring, and host sampling to confirm transmission foci. This study demonstrates the added value of molecular diagnostics for complementing traditional parasitological methods and guiding surveillance and control strategies in areas of emerging endemicity.
Discovery of two novel mutations, R52H and N868D, in the voltage-gated sodium channel of Aedes aegypti associated with pyrethroid resistance.
Chung HH, Teng HJ, Chen SL
PLoS Negl Trop Dis · 2026 May · PMID 42189875 · Full text
Aedes aegypti is the primary vector of arboviruses, including the dengue virus. Insecticide-based vector control remains a key strategy for reducing mosquito populations and disrupting disease transmission; however, its...
Aedes aegypti is the primary vector of arboviruses, including the dengue virus. Insecticide-based vector control remains a key strategy for reducing mosquito populations and disrupting disease transmission; however, its effectiveness is increasingly challenged by resistance. Identifying resistance mechanisms is crucial for monitoring resistance trends and informing policy decisions for vector control and disease prevention. We aimed to investigate the voltage-gated sodium channel (vgsc) mutations in pyrethroid-resistant Ae. aegypti strains. In this study, we established a cypermethrin-resistant Ae. aegypti strain from field-collected mosquitoes in 2016 and performed whole-genome sequencing to identify resistance-associated vgsc mutations. Additionally, we genotyped field Ae. aegypti collected in 2024 to assess the variation and prevalence of resistance-related mutations. Our findings confirmed that R52H and N868D are associated with resistance, with R52H co-occurring with S989P+V1016G and N868D co-occurring with F1534C. The widespread presence of R52H and N868D, along with their co-circulation with other resistance-associated mutations in the field population, suggests that these mutations have been maintained under intense selection pressure. Furthermore, we identified 12 haplotypes and suggested a potential evolutionary trajectory based on co-occurrence patterns of mutation events. The emergence and persistence of novel vgsc mutations in field populations highlight the ongoing expansion of insecticide resistance in Taiwan and globally, which threatens the efforts for disease vector control. Understanding the functional impact of these mutations is essential for comprehensive monitoring and evaluating pyrethroid resistance dynamics. Systematic surveillance program is required to track resistance trends and guide evidence-based vector control strategies that ensure effective disease prevention and public health protection.
Climate change and Plasmodium vivax Malaria Risk in Brazil: Developing adaptive tool for Brazilian Municipalities.
C M Sousa T, Hacon SS, Pedra GU … +7 more , Lemos CMG, Sallum MAM, Ladeia-Andrade S, Reis FB, Arcoverde G, Alves L, Ometto J
PLoS Negl Trop Dis · 2026 May · PMID 42189861 · Full text
Climate change impacts ecosystems and health sectors, increasing the incidence of climate-sensitive diseases like malaria, mainly in tropical countries. This study assesses malaria risk, particularly related to Plasmodiu...
Climate change impacts ecosystems and health sectors, increasing the incidence of climate-sensitive diseases like malaria, mainly in tropical countries. This study assesses malaria risk, particularly related to Plasmodium vivax, under climate change scenarios for 2030 and 2050 for two greenhouse gas emission scenarios (RCP 4.5 and RCP 8.5), using the AdaptaBrasil MCTI approach, which supports decision-makers in enhancing climate adaptation strategies. A multilevel analysis was employed to identify key climate variables influencing malaria incidence (temperature, relative humidity, and the Simple Daily Intensity Index (SDII)). A logistic Binary Model was applied to estimate the climate threat associated with malaria incidence in all Brazilian municipalities for baseline and future scenarios. The Vulnerability Index, comprising Sensitivity and Adaptive Capacity dimensions, highlighted social susceptibility and healthcare access as crucial factors driving higher vulnerability. Road networks and land use factors shaped the Exposure Index, and the Climate Threat Index was based on maximum temperature, SDII, and relative humidity. Under both scenarios, the findings show a growing malaria risk across Brazil, with the most significant impact in the Amazon, expanding to the other regions, mainly the Southeast and Northeast, by 2050. Maximum temperature increases (β = 0.35) emerged as the most influential factor, followed by SDII (β = 0.19) and relative humidity (β = 0.12). These results emphasize the need for targeted public health and environmental interventions to address rising malaria risks, particularly in the Amazon. This study offers critical insights into the relationship between climate change and malaria, informing future policies for climate adaptation and public health preparedness in Brazil.
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