PLoS Neglected Tropical Diseases[JOURNAL]
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200 papers
Flubendazole 2.0: Designing a large field trial in dogs for a challenging setting.
Dupper AC, Ramesh B, Binkley L … +17 more , Cleveland CA, Haynes EK, Verocai GG, Saleh MN, Yabsley MJ, Geary TG, Mackenzie CD, Torres-Velez F, Elder DL, Najahi-Missaoui W, Unterwegner K, Zirimwabagabo H, Sidouin MK, Tchindebet Oaukou P, Richard Ngandolo BN, Weiss AJ, Garabed R
PLoS Negl Trop Dis · 2026 Jul · PMID 42391310 · Full text
Dracunculiasis, or Guinea worm disease (GWD), was targeted for eradication in 1986 after which, the annual incidence decreased by over 99.9%. As human cases of GWD near elimination, dogs have become the primary reservoir...
Dracunculiasis, or Guinea worm disease (GWD), was targeted for eradication in 1986 after which, the annual incidence decreased by over 99.9%. As human cases of GWD near elimination, dogs have become the primary reservoir for the parasite and remain a challenge for eradication efforts. The high burden of GWD in dogs relative to humans highlights the need for therapeutic interventions in conjunction with behavioral interventions. Laboratory experiments in ferrets demonstrated that flubendazole is partially effective in inhibiting the infectivity of D. medinensis larvae. However, the implementation of large clinical field trials in dogs has proven challenging in settings where access to study areas is unreliable throughout the year and attrition is high. Alternative study design approaches are required to address these challenges. This paper outlines challenges encountered during a previous field trial and ways in which these challenges were addressed in the study design and implementation for a second clinical trial of flubendazole in dogs. The results of the second clinical trial are outlined in a separate manuscript.
Temporal and spatial patterns of Leprosy in Uganda, 2020-2024: A nationwide surveillance analysis.
Abbo G, Migisha R, Mfitundinda E … +8 more , Bulage L, Amanya G, Mulindwa A, Kengonzi R, Turyahabwe S, Luzze H, Kwesiga B, Ario AR
PLoS Negl Trop Dis · 2026 Jul · PMID 42391308 · Full text
INTRODUCTION: Despite sustained elimination efforts, leprosy transmission persists in Uganda. The World Health Organization's Towards Zero Leprosy strategy targets zero infections and Grade 2 Disability (G2D) by 2030. Ug...
INTRODUCTION: Despite sustained elimination efforts, leprosy transmission persists in Uganda. The World Health Organization's Towards Zero Leprosy strategy targets zero infections and Grade 2 Disability (G2D) by 2030. Uganda's National TB and Leprosy Strategic Plan aims to reduce child cases to <3% and G2D to <5%. We assessed temporal trends and spatial distribution of leprosy in Uganda from 2020-2024 to evaluate progress toward these targets. METHODS: We conducted a descriptive analysis using national surveillance data from the District Health Information System 2 (DHIS2). Newly diagnosed leprosy cases reported between 2020 and 2024 were analyzed by age, sex, clinical type, and disability grade. Incidence was calculated using annual mid-year population estimates from the Uganda Bureau of Statistics. Temporal trends were assessed using the Mann-Kendall test and Sen's slope estimator. Spatial distribution of incidence, child cases, and G2D proportions was examined using QGIS at the regional and district levels. RESULTS: Between 2020 and 2024, Uganda reported 1,935 new leprosy cases, with an overall incidence of 8.8 per 1,000,000 population. Multibacillary disease accounted for 86% of cases, and 21% presented with Grade 2 Disability (G2D). Children aged ≤15 years comprised 14% of cases, consistently exceeding the national elimination target of 3%. No significant monotonic trend was observed in overall incidence (p = 0.89), child proportion (p = 0.069), or G2D proportion (p = 0.14). Spatial analysis demonstrated persistent concentration of high incidence in the West Nile region, with 9 of 13 districts bearing the highest disease burden. Elevated G2D proportions were observed intermittently in the Teso and Ankole regions. CONCLUSION: Leprosy incidence in Uganda remained relatively stable from 2020 to 2024; however, persistently high proportions of multibacillary disease, child cases, and G2D indicate ongoing transmission and delayed diagnosis in specific regions. Targeted interventions, including strengthened contact tracing and active case detection in high-burden areas, are essential to accelerate progress toward national elimination goals.
Prevalence and risk factors of asymptomatic Plasmodium spp. infection in the military population of the Colombian National Army.
Oliveros C, Correa-Cárdenas CA, Orjuela LI … +17 more , Albarracin L, Márquez EK, Alvarado MT, Pérez J, Chacón D, Ortíz FLS, Romero Y, Ruiz-Jara P, Herrera-Jiménez V, Daza CD, Duque MC, Rivera-Rincón Y, Méndez C, Cantillo-Barraza O, Patiño LH, Rámirez JD, Cucunubá ZM
PLoS Negl Trop Dis · 2026 Jul · PMID 42391276 · Full text
BACKGROUND: Asymptomatic malaria plays a critical role in sustaining transmission in endemic regions, yet its magnitude and determinants remain insufficiently characterized in military populations frequently exposed duri...
BACKGROUND: Asymptomatic malaria plays a critical role in sustaining transmission in endemic regions, yet its magnitude and determinants remain insufficiently characterized in military populations frequently exposed during field operations. This study sought to estimate the prevalence of asymptomatic Plasmodium spp. infection and identify associated risk factors among Colombian military personnel deployed in high-endemicity areas in 2022. METHODOLOGY/PRINCIPAL FINDINGS: A cross-sectional survey was conducted in four departments with the highest malaria transmission (Antioquia, Chocó, Córdoba, and Nariño). A total of 773 participants underwent thick blood smear microscopy, rapid diagnostic testing (RDT), conventional PCR, and real-time PCR. The prevalence of asymptomatic infection detected by conventional PCR/qPCR was 2.59%, with the highest municipal rates observed in El Bagre and Carepa (Antioquia), followed by Tumaco, Quibdó, and Tierralta. P. falciparum accounted for most infections (60%), followed by P. vivax (25%) and mixed infections (15%). qPCR demonstrated the greatest diagnostic sensitivity. Statistical analyses identified frequency of bed net use, number of lifetime and recent malaria episodes, department of origin, department and duration of patrol, number of patrol sites, and age as the main associated risk factors. CONCLUSIONS/SIGNIFICANCE: These findings highlight the relevance of asymptomatic Plasmodium spp. infections among Colombian military personnel and underscore the need to integrate their detection into routine malaria surveillance. Strengthening identification of low-density infections in highly exposed populations may contribute to reducing transmission, improving clinical management, and enhancing operational readiness in endemic areas.
Mobility and non-household environments: Understanding dengue transmission patterns in urban contexts.
Peña-García VH, Ndenga BA, Mutuku FM … +3 more , Bisanzio D, LaBeaud AD, Mordecai EA
PLoS Negl Trop Dis · 2026 Jul · PMID 42391249 · Full text
Households (HH) have been traditionally described as the main environments where people are at risk of dengue and other arbovirus infections. Mounting entomological evidence suggests a larger role for environments other...
Households (HH) have been traditionally described as the main environments where people are at risk of dengue and other arbovirus infections. Mounting entomological evidence suggests a larger role for environments other than HH. Recently, an agent-based model (ABM) estimated that over half of infections occur in non-household (NH) environments such as workplaces, markets, and recreational sites. Despite the inferred importance of NH sites, we do not yet know how their urban spatial configurations, and human and vector mobility between them, affects their role in dengue transmission. To address this gap, we expanded an ABM calibrated with field data from Kenya to examine movement of people and vectors under different spatial configurations of buildings. We assessed the number of people traveling between HH and NH and the distances traveled, in three urban configurations: NH distributed randomly (scattered), concentrated in a single center, or clustered in multiple centers. Across simulations, the number of people moving was the most influential variable, with higher movement between HH and NH increasing case numbers. The number of cases was also higher when NH were scattered compared to centered or clustered. Intriguingly, the distance people traveled from HH to NH had little effect on dengue burden but influenced the spatial clustering of infections. These findings underscore the role of NH as major spreaders of infections between HH and NH environments, and the importance of human movement in driving dengue dynamics.
Hantavirus stability and inactivation.
Vandenabeele L, Ayanwale A, Pietschmann T … +1 more , Nilsson-Payant BE
PLoS Negl Trop Dis · 2026 Jul · PMID 42391226 · Full text
Hantaviruses are zoonotic viruses that can cause highly pathogenic disease, including hantavirus cardiopulmonary syndrome (HCPS) and haemorrhagic fever with renal syndrome (HFRS), in humans with case-fatality rates of up...
Hantaviruses are zoonotic viruses that can cause highly pathogenic disease, including hantavirus cardiopulmonary syndrome (HCPS) and haemorrhagic fever with renal syndrome (HFRS), in humans with case-fatality rates of up to 50%. However, our understanding of the basic viral life cycle and the underlying causes of viral pathogenesis remains sparse, in large part due to a lack of molecular biology tools for hantaviruses and the need to work in high-containment laboratory facilities with these viruses. The stability and inactivation of hantavirus particles has been examined in some limited previous studies, however, a comprehensive, detailed and robust investigation of the stability of multiple hantaviruses has not been performed yet. Here, we investigated the kinetics of infectious Tula virus (TULV) particle production in Vero E6 cells and subsequent stability in cell culture media. In addition, we evaluated the stability of infectious virus particles in response to different physical and environmental stresses, including heat, freezing, dehydration and UV exposure, answering key questions about the environmental transmission potential of hantaviruses. Interestingly, we observed a remarkable stability of TULV when stored at room temperature or colder, as well as after dehydration, which suggests that hantaviruses could remain infectious for a sustained period of time after being secreted by their host species. Subsequently, we determined the ability of commonly used virus inactivation methods, including RNA and protein extraction buffers, to inactivate TULV both in a cell-free and cell-associated context and found that TULV was efficiently inactivated by all these methods similar to other enveloped RNA viruses. Finally, we successfully validated the complete inactivation using these inactivation methods using the highly pathogenic HCPS-causing New World Andes virus (ANDV) and the HFRS-causing Old World Hantaan virus (HTNV). These results provide valuable information about safe and effective inactivation methods of viral samples and about the environmental risk potential of hantaviruses.
Disability as a neglected outcome of neglected tropical diseases: A systematic review.
Barrionuevo CCLB, Valente JDS, Silva BMD … +10 more , Goulart CDL, Maciel A, Santos-de-Araújo AD, Amaral CMSSBD, Silva Junior EFD, Santos SVAD, Gomes E, Cubas-Vega N, Arêas GPT, Almeida-Val F
PLoS Negl Trop Dis · 2026 Jul · PMID 42384755 · Full text
BACKGROUND: Neglected tropical diseases (NTDs) affect more than one billion people worldwide, predominantly in low-resource settings. While substantial progress has been made in reducing transmission and mortality, the l...
BACKGROUND: Neglected tropical diseases (NTDs) affect more than one billion people worldwide, predominantly in low-resource settings. While substantial progress has been made in reducing transmission and mortality, the long-term disabilities resulting from NTDs remain insufficiently recognized and inadequately addressed within control programs. OBJECTIVE: To identify, describe, and systematize the types of disabilities reported among individuals affected by NTDs, providing a comprehensive overview of the magnitude and diversity of long-term functional impairments associated with these conditions. METHODS: This systematic review was conducted in accordance with PRISMA 2020 guidelines. A comprehensive search was performed in PubMed, Cochrane Central, Embase, CINAHL, LILACS, and Web of Science databases, without restrictions on language or publication date. Studies reporting long-term disabilities or sequelae in individuals diagnosed with WHO-listed NTDs were included. Data on study characteristics, population demographics, and disability types were extracted and synthesized descriptively. Methodological quality was assessed using design-specific tools (MINORS, CARE checklist, and Jadad scale). RESULTS: The initial search identified 958 records across databases. After removal of duplicates (n = 478), 480 records were screened, of which 310 were assessed for full-text eligibility. Following the application of inclusion and exclusion criteria, 130 studies were included in the final analysis, encompassing 551,574 individuals from 25 countries. Overall, 29% (n = 158,104) of evaluated individuals presented with at least one form of disability. Physical and motor impairments were the most prevalent (24.6%, n = 135,683), predominantly associated with leprosy-related neuropathic and musculoskeletal sequelae. Visual impairment was the second most frequent disability (1.81%, n = 10,007), largely attributable to trachoma and onchocerciasis. Cardiovascular, neurological, psychological, and social impairments were also reported. Considerable heterogeneity and underreporting of disability outcomes were observed across studies. CONCLUSIONS: Disability represents a substantial and underappreciated outcome of NTDs, extending far beyond infection-related morbidity. The high burden of long-term physical, visual, and other functional impairments underscores the urgent need to integrate disability assessment, rehabilitation services, and disability-inclusive development into NTD control strategies. Addressing these gaps is essential to advance patient-centered care and achieve the broader goals of the WHO NTD Roadmap and Universal Health Coverage.
Massive scabies outbreak in Rohingya refugee camps, Cox's Bazar: Epidemiology and impact of a mass drug administration (MDA) campaign - A retrospective study.
Halder CE, Hasan MA, Okello JC … +11 more , Otieno D, Soma ER, Das PP, Rahman MM, Atiquzzaman M, Tassdik H, Barasa DW, Poly JT, Al Mamun A, Bhuiyan ATMRH, Prue UM
PLoS Negl Trop Dis · 2026 Jul · PMID 42384720 · Full text
BACKGROUND: Since 2021, Rohingya refugee camps in Cox's Bazar, Bangladesh, have experienced a significant and concerning increase in the prevalence of scabies. In response to the massive outbreak, an extensive Mass Drug...
BACKGROUND: Since 2021, Rohingya refugee camps in Cox's Bazar, Bangladesh, have experienced a significant and concerning increase in the prevalence of scabies. In response to the massive outbreak, an extensive Mass Drug Administration (MDA) campaign was conducted by WHO Bangladesh, in collaboration with the Government of Bangladesh and Health Sector partners, from November 29, 2023, to February 01, 2024. OBJECTIVES: The objectives of the study were: a) to determine the epidemiological characteristics (i.e., magnitude, age-sex distribution, and attack rate) of the scabies outbreak in the Rohingya refugee camps; and b) to evaluate the impact and durability of MDA in reducing the burden of scabies in the refugee camps. METHODOLOGY: This was a retrospective observational study that utilized deidentified and anonymized data from 35 health facilities of the International Organization for Migration (IOM) spanning the period from January 1, 2021, to December 31, 2024. RESULTS: A total of 384,852 cases of scabies were reported, with an overall attack rate of 5,562.59 scabies cases per 10,000 population over 4 years. Females had a slightly higher case proportion (53.51%) and attack rate (ARR: 1.104, p < 0.001). Children under 5 years (36.31%) had the highest burden and attack rate, about twice the overall attack rate. Using this age group as reference, the attack rate declined significantly with increasing age, 5,561.85 among adolescents (ARR: 0.496, p < 0.001) to 4,377.88 among individuals over 60 years (ARR: 0.390, p < 0.001). 77% of the cases were reported among the Rohingya refugees; however, the attack rate was higher among host communities (7,721.34 per 10,000 vs. 5,138.24 per 10,000 among refugees). Overall, 5.80% of scabies cases were associated with secondary bacterial infections. Interrupted time series (ITS) analysis showed a sharp and immediate decline in scabies cases following MDA initiation, representing a reduction of 1,885 cases per week (p < 0.001) - equivalent to a weekly decline of approximately 100% from the pre-MDA peak. The decline persisted for 6 months (decreasing trend of 69.98 cases/week, p < 0.001), after which a statistically significant upward rebound was observed (72.04 additional cases per week, p = 0.002). CONCLUSION: The study revealed a high burden of scabies among the Rohingya refugees and the adjacent host community. MDA was an effective approach for a rapid and substantial reduction of the disease burden. However, the impact cannot be sustained unless the underlying factors of the scabies outbreak are addressed.
Elimination of gambiense human African trypanosomiasis as a public health problem in Republic of Guinea: Paving the way for zero transmission.
Kagbadouno M, Camara O, Diallo BM … +26 more , Camara AD, Soumah A, Leno M, Béavogui F, Gassama MD, Camara I, Coulibaly B, Kaba D, Camara A, Boiro S, Ilboudo H, Rayaisse JB, MacLeod A, Ndungu J, Bieler S, Bessell P, Ott D, Lejon V, Ravel S, Courtin F, Solano P, Jamonneau V, Bart JM, Rotureau B, Bucheton B, Camara M
PLoS Negl Trop Dis · 2026 Jul · PMID 42384642 · Full text
The Republic of Guinea has faced an important challenge with human African trypanosomiasis (HAT), which was endemic over the last century. After initial control in the 1960s-1970s, HAT resurged in the 1990s along the Gui...
The Republic of Guinea has faced an important challenge with human African trypanosomiasis (HAT), which was endemic over the last century. After initial control in the 1960s-1970s, HAT resurged in the 1990s along the Guinean coast, driven by economic and demographic pressures on the mangrove ecosystem. In response, the Guinean government established a national control program in 2002, focusing on medical mass screenings. In 2012, vector control using tiny targets was introduced in the East Boffa focus to reduce fly density and human-vector contact. However, the Ebola epidemic from 2013 to 2016 disrupted these efforts, leading to a reliance on passive screening. Resuming screenings in 2016-2017 revealed increased cases in all foci except the East Boffa area, where vector control had been effective. Vector control continued during the SARS-CoV2 pandemic and at the same time targeted door-to-door screenings were introduced to target high-risk individuals. Since 2018, around 30,000 at-risk individuals have been screened annually. These strategies reduced the total number of new cases below 1 per 10,000 inhabitants in endemic areas over the period 2019-2023, allowing to validate the elimination of HAT as a public health problem. The Guinean team and partners then focused on systematic spatial monitoring of patients and community engagement in vector control. The program also integrates control of other neglected tropical diseases and addresses new research questions, especially about anatomical and animal reservoirs for parasites. These efforts, combined with implementation of improved diagnostic tests and new oral treatments, through active involvement in multiple clinical trials and studies, now aim to interrupt HAT transmission by 2030.
Implementing mass dog rabies vaccination through a community-based continuous approach: A socio-anthropological process evaluation.
Duamor CT, Lankester F, Hampson K … +6 more , Lugelo A, Lushasi KS, Sambo M, Changalucha JJ, Czupryna A, Wyke S
PLoS Negl Trop Dis · 2026 Jun · PMID 42378304 · Full text
INTRODUCTION: Mass dog vaccination to control rabies usually involves centralized planning and team-led annual campaigns. We evaluated the implementation processes of a decentralized, community-based continuous approach...
INTRODUCTION: Mass dog vaccination to control rabies usually involves centralized planning and team-led annual campaigns. We evaluated the implementation processes of a decentralized, community-based continuous approach to mass dog vaccination (CBC-MDV), delivered as an arm of a randomized controlled trial (RCT) across the Mara region, Tanzania. We employed the socio-anthropological framework to assess the implementation process of the CBC-MDV approach. METHODS: We embedded a mixed method process evaluation into the RCT and conducted in-depth interviews with district and village-level implementers, focus group discussions with ward-level implementers and community leaders and members, non-participant observation of the campaigns, and an audit of the vaccination campaign activities. We analyzed the resulting data following the five domains of the socio-anthropological framework. FINDINGS: Refining the five domains, we report that 1) Environmental context affected CBC-MDV campaigns, which were interrupted by rainy and farming seasons, school schedules, market days and funerals, whilst village size and routes of access reduced their reach. 2) Social difference and pressures, and community involvement influenced delivery; cultural celebrations and social statuses of implementors hindered delivery, while by-laws and perceived rabies risk improved delivery. Community involvement facilitated implementation, but there was a need to strategically select who did what and how. 3) Strategies and incentives affected implementers, who were motivated by training and resources provided, and delivered 88% of components as planned. 4) Socio-materiality and resilience of intervention strategies and tools made it feasible to deploy the required equipment across a wide geographic scale, with adequate vaccination opportunities, but implementers found house-to-house and on-demand strategies demanding and less effective than central point delivery. 5) Governance also affected delivery with closer supervision by veterinary officials and community leaders, and co-reflexive appraisal of implementation with communities constrained by resource limitations. CONCLUSIONS: CBC-MDV with local storage of dog vaccine can be deployed across the rural landscape of Tanzania. Deeper involvement of communities in planning when and how campaigns are conducted, and in the appraisal of outcomes can significantly address barriers to dog-owner participation. The socio-anthropological framework provides a useful framing for understanding intervention delivery but not refinement for use cases.
Diagnostic competence and health worker knowledge of female genital schistosomiasis management in a rural Ghanaian district.
Gbeze C, Karikari AB, Asirifi SA … +5 more , Alahaman NB, Appiah SCY, Essé-Diby C, Mensah GI, Addo KK
PLoS Negl Trop Dis · 2026 Jun · PMID 42378303 · Full text
BACKGROUND: Schistosomiasis is a neglected tropical disease with a greater burden in Africa, including Ghana. Female Genital Schistosomiasis (FGS), a gynaecological manifestation of urogenital schistosomiasis, is often m...
BACKGROUND: Schistosomiasis is a neglected tropical disease with a greater burden in Africa, including Ghana. Female Genital Schistosomiasis (FGS), a gynaecological manifestation of urogenital schistosomiasis, is often missed or misdiagnosed due to similarities with sexually transmitted infections and other gynaecological infections, with limited ease of health worker identification and diagnostic capability. This study assessed healthcare workers' knowledge and diagnostic capacity for FGS in the Central Gonja District of Ghana. METHODS: A quantitative cross-sectional study sampled 237 healthcare workers from 19 facilities near the Black and the White Volta rivers using a three-phase multistage sampling process. Data was collected via a self-administered Kobo Toolbox questionnaire, focusing on sociodemographic factors, whether facilities had functional screening tools for FGS and health workers' capacity to diagnose and treat these conditions. Analysis was conducted in Statistical Package for Social Sciences (SPSS), employing descriptive statistics and Pearson's chi-square tests to assess inferential associations between variables and health workers' knowledge of FGS/schistosomiasis, which served as the main outcome variable. RESULTS: The study involved health workers with a mean age of 31.6 ± 4.18 years, of whom 52.3% were male. Knowledge gaps were significant: only 30% (71/237) demonstrated good understanding of schistosomiasis and merely 16.9% (40/237) showed adequate knowledge of FGS. Despite 91.6% recognition of schistosomiasis ('Bilharzia'), knowledge of genital manifestations lagged severely (FGS: 26.8%, MGS (Male genital schistosomiasis): 18.1%). While demographic factors showed no association, experienced staff demonstrated better FGS knowledge (p = 0.003). Critical health system deficiencies emerged; 74% of facilities lacked laboratories, 90% lacked praziquantel and 100% lacked FGS diagnostic capacity. Even among clinicians, < 43% knew standard FGS treatment and only 1/3 considered FGS in relevant diagnoses. CONCLUSION: In the Central Gonja District of the savannah region located in the northern part of Ghana, where schistosomiasis prevalence is classified as moderate (10-49%), healthcare workers demonstrated limited knowledge and diagnostic capacity regarding FGS. These findings highlight the need to integrate FGS into reproductive health guidelines, strengthen healthcare worker training and improve diagnostic resources for early detection and management in endemic settings.
Experimental evidence of early-phase transmission of Yersinia pestis by Synopsyllus fonquerniei and Xenopsylla brasiliensis.
Rakotobe Harimanana R, Sebbane F, Harimalala M
PLoS Negl Trop Dis · 2026 Jun · PMID 42378209 · Full text
BACKGROUND: Flea-borne transmission of the plague bacillus, Yersinia pestis, occurs through two regurgitation-based mechanisms. One, called early-phase transmission (EPT), takes place within 24-96 hours post-infection th...
BACKGROUND: Flea-borne transmission of the plague bacillus, Yersinia pestis, occurs through two regurgitation-based mechanisms. One, called early-phase transmission (EPT), takes place within 24-96 hours post-infection through a poorly understood mechanism. The second requires an intrinsic incubation period and relies on the formation of a biofilm obstructing the flea's proventriculus. Although these mechanisms have been described in different flea species, they have never been characterized in Xenopsylla brasiliensis and Synopsyllus fonquerniei, which are two flea vectors suspected and confirmed to contribute to Y. pestis transmission in Madagascar. Because EPT may facilitate rapid pathogen spread, this study aimed to experimentally assess the ability of both flea species to transmit Y. pestis via EPT. METHODOLOGY: Cohorts of starved X. brasiliensis and S. fonquerniei fleas were artificially infected with Y. pestis. From day 1 (D1) to day 4 (D4) post-infection (p.i.), pools of ten infected fleas were fed on sterile mouse blood. After feeding, bacterial loads in both the blood and the fleas were determined by Colony Forming Unit (CFU) counts on blood agar to assess bacterial transmission. Fleas were also observed under a binocular microscope to determine whether the foregut was blocked, as indicated by the presence of fresh blood in the foregut but not in the midgut. PRINCIPAL FINDINGS: The results showed that X. brasiliensis and S. fonquerniei were able to transmit Y. pestis as early as 24 hours p.i., although transmission events were infrequent. No correlation was found between flea bacterial load (ranging from 4.0 x 101 to 4.4 x 105 CFU) and transmission success. Blockage was observed in 1% of S. fonquerniei (D3 and 4 p.i) and 0.75% of X. brasiliensis (D4 p.i.), without detectable transmission by these blocked fleas during the experimental window. CONCLUSION: This study provides the first experimental evidence that X. brasiliensis and S. fonquerniei can support early-phase transmission of Y. pestis and are capable of developing proventricular blockage under laboratory conditions. These findings refine our understanding of the potential contribution of these flea species to plague transmission dynamics in Madagascar.
Prevalence, distribution, and phylogenetics of the tick-borne relapsing fever spirochete Borrelia turicatae in the soft tick Ornithodoros turicata americanus in Florida.
Canino N, Torhorst CW, Botero-Cañola S … +2 more , Wilson KN, Wisely SM
PLoS Negl Trop Dis · 2026 Jun · PMID 42371983 · Full text
In the southwestern United States, the occurrence and potential for disease spread of Tick-Borne Relapsing Fever (TBRF) has been studied. In Florida, Borrelia pathogens that cause TBRF have only been found in two domesti...
In the southwestern United States, the occurrence and potential for disease spread of Tick-Borne Relapsing Fever (TBRF) has been studied. In Florida, Borrelia pathogens that cause TBRF have only been found in two domestic dogs (Canis lupus familiaris), yet the soft tick vector, Ornithodoros turicata americanus, is commonly found throughout the state. The goal of our study was to provide the first large-scale investigation of this disease system in the southeastern US. Our objectives were to: 1) describe the occurrence and prevalence of Borrelia spp. in ticks found throughout their distribution; and 2) phylogenetically describe the pathogen species compared to other isolates of B. turicatae. We pooled ticks by sample location and extracted DNA from over 3,000 ticks systematically collected throughout Florida. Conventional PCR was used with a genus-wide IGS primer to detect any Borrelia spp. present in the ticks. We discovered a low but detectable prevalence (7/745; 0.94%) of the pathogen within localized foci, which could present an epidemiological risk to humans and companion animals in those areas. We Sanger sequenced the 7 pools that were positive for Borrelia spp. and created a phylogenetic tree with our samples and 27 previously described isolates. Our tree showed clustering of our samples into two distinct clades, one that fit with Texas isolates and one that was entirely distinct. We hypothesized that a combination of biogeographic and host influences may be the driving force behind the history of Borrelia turicatae in Florida. Future research is needed to improve our understanding of the drivers of pathogen occurrence and the phylogeography of this species. By understanding the occurrence and phylogenetics of Borrelia turicatae in the state, we can better comprehend and mitigate the risk of this neglected vector-borne disease for humans and companion animals in Florida.
The cobras (genus Naja) of Myanmar: An updated species list with information on identification, distributions, and medical importance.
Balchan NR, Oo WP, Wogan GOU … +2 more , Keyler DE, Wüster W
PLoS Negl Trop Dis · 2026 Jun · PMID 42371977 · Full text
The cobra diversity of Myanmar has long been a source of confusion, complicating public health responses to snakebites resulting from this medically important genus. By integrating distributional data, natural history in...
The cobra diversity of Myanmar has long been a source of confusion, complicating public health responses to snakebites resulting from this medically important genus. By integrating distributional data, natural history information, and clinical evidence, we clarify the composition and distribution of Myanmar's cobra fauna and evaluate the implications for envenoming and snakebite management. We confirm the presence of five cobra species (Naja fuxi, N. kaouthia, N. mandalayensis, N. siamensis, and N. sumatrana) in Myanmar through voucher specimens and/or diagnostic photographic records and identify one additional unconfirmed species (N. sagittifera) that may occur in the country based on distributional proximity. Encounter records showed significant within-year temporal variation, with reports peaking in December and during the dry season. Because data derive from opportunistic citizen science submissions, these patterns likely reflect seasonal differences in detection and human activity rather than biological seasonality. Differences from wet-season peaks reported elsewhere highlight the importance of sampling framework in shaping apparent temporal trends. Review of clinical and toxicological information shows that only one species is represented in locally produced antivenom, raising concern about limited cross-neutralization for other cobra species in the country. Traditional practices remain common in many communities and include harmful methods that delay access to medical care or worsen injuries. Clinical evidence demonstrates that neurotoxicity, respiratory failure, and localized tissue destruction are the principal complications of cobra envenoming, often requiring antivenom therapy, airway support, mechanical ventilation, infection management, and surgical intervention in severe cases. The broader-than-recognized diversity of cobras in Myanmar, combined with high encounter probabilities, synanthropic tendencies, and gaps in public awareness, continues to hinder effective management of snakebite. Improved community education, expanded venom and antivenom research, and timely access to appropriate medical care are essential for reducing the burden of cobra envenomation in Myanmar.
Spatiotemporal differentiation of Plasmodium vivax populations in the western Greater Mekong Subregion using a 22-SNP barcode.
Wu Z, Zeng W, Brashear AM … +11 more , Wu Y, Wang L, Soe MT, Aung PL, Sattabongkot J, Kyaw MP, Yang Z, Cao Y, Zheng L, Cui L, Zhao Y
PLoS Negl Trop Dis · 2026 Jun · PMID 42371949 · Full text
BACKGROUND: A high-resolution molecular tool for tracking and differentiating closely-related Plasmodium vivax populations is critically needed. This study aimed to develop and validate a novel single nucleotide polymorp...
BACKGROUND: A high-resolution molecular tool for tracking and differentiating closely-related Plasmodium vivax populations is critically needed. This study aimed to develop and validate a novel single nucleotide polymorphism (SNP) barcode to monitor the progress of malaria elimination in the Great Mekong Subregion (GMS). METHODOLOGY/PRINCIPAL FINDINGS: A total of 210 P. vivax clinical samples were collected across four time points in three international border areas: China-Myanmar border, Thailand-Myanmar border, and Bangladesh-Myanmar border. Parasites were genotyped at 36 SNPs using MassARRAY technology (Sequenom), with Sanger sequencing validation for low-efficiency loci. The complexity of infection (COI) was estimated via a maximum likelihood approach implemented in COIL, while genetic diversity metrics were computed in GenAIEx version 6.5. Population differentiation was assessed through molecular variance analysis, Mantel rank test, and pairwise FST estimation. Genetic structure was resolved using principal component analysis, phylogenetic analysis, and ADMIXTURE. 198 samples were successfully genotyped at 22 validated SNPs, revealing 37.9% polyclonal infections. The proportion of polyclonal infections differed significantly among the five P. vivax populations (P = 0.0001, Pearson Chi-square test, χ2 = 23.15), with 2020 CMB samples having the highest proportion (56.1%). The average COI was highest in BMB parasites (1.109 ± 0.007). The TMB 2018 samples exhibited the maximal nucleotide diversity (π = 0.342 ± 0.033) and expected heterozygosity (He = 0.325 ± 0.04). The P. vivax populations from the western GMS showed significantly reduced genetic diversity in recent years compared to earlier timepoints (0.372 ± 0.009 vs. 0.426 ± 0.009; P < 0.0001, Student's t-test). Pairwise FST values indicated moderate to high genetic differentiation (0.165 - 0.417) across nine population pairs, except for the temporally proximal CMB populations, which showed low differentiation. Structure analysis consistently resolved three discrete genetic clusters corresponding to CMB, TMB, and BMB parasite populations. CONCLUSIONS/SIGNIFICANCE: This 22-SNP barcode provides a high-resolution genotyping tool capable of differentiating P. vivax parasite infections from the western GMS. Our data demonstrate that sustained malaria control interventions drive the fragmentation of P. vivax populations into genetically distinct transmission foci, creating opportunities for elimination strategies in border hotspots.
Reinfection dynamics of owned dogs with Echinococcus granulosus sensu lato in endemic rural areas of central Iran: Implications for cystic echinococcosis control.
Mirbadie SR, Shamsaddini S, Rahimi MT … +5 more , Matini M, Mohaghegh MA, Baneshi MR, Fasihi Harandi M, Fallah M
PLoS Negl Trop Dis · 2026 Jun · PMID 42371948 · Full text
BACKGROUND: Cystic echinococcosis (CE), caused by the tapeworm Echinococcus granulosus sensu lato (E. granulosus s. l.), is highly endemic worldwide including in Iran, where dogs serving as definitive hosts play a critic...
BACKGROUND: Cystic echinococcosis (CE), caused by the tapeworm Echinococcus granulosus sensu lato (E. granulosus s. l.), is highly endemic worldwide including in Iran, where dogs serving as definitive hosts play a critical role in transmission dynamics of the disease. Regular deworming of dogs is an essential part of any successful CE control program. However, dogs can become easily reinfected after praziquantel (PZQ) administration, and the rate of reinfection of dogs in an endemic area is considered an indicator of the intensity of CE transmission. This study aimed to evaluate reinfection rate in the owned dogs after PZQ treatment in Semnan province, in North of Iran. METHODS: A cohort of 381 guard and sheepdogs was monitored for 15 months post-treatment with PZQ. Reinfection was assessed at 3, 6, 9, 12, and 15 months by fecal sampling. Samples were microscopically examined for taeniid eggs after formalin-ether sedimentation, and were confirmed by PCR using E. granulosus s. l.-specific primers. Kaplan-Meier survival analysis was used to calculate the cumulative survival rate over a 15-month period. A Cox proportional hazards regression model was employed to identify risk factors associated with the time to reinfection with E. granulosus s.l. RESULTS: Fecal samples from 151 sheepdogs and 230 guard dogs from 290 farms, were examined. At baseline, microscopic and copro-PCR analyses revealed that 12.6% positive for taeniid eggs, of which 31 samples (8.1%) were positive for E. granulosus s. l. The reinfection rate was estimated as 9.6%, 10.7%, 15.6%, 22.5%, and 33.2% at 3, 6, 9, 12, and 15 months after initial treatment with PZQ, respectively. Sheepdogs showed significantly higher reinfection risks (29.8%) compared to the guard dogs (16.7%). Dogs whose owners practiced home slaughter were 2.02 times more likely to become reinfected. Only 17.3% (66/381) of the dogs were reported to be regularly dewormed by the owners. CONCLUSION: This study demonstrates that re-infection of dogs with E. granulosus s.l. is common in CE-endemic regions of Iran. The high rate of re-infection has significant implications for CE control, particularly in determining the most effective frequency for administering PZQ to prevent sustained transmission.
Editorial Note: Tick-borne relapsing fever Borreliosis, a major public health problem overlooked in Senegal.
PLOS Neglected Tropical Diseases Editors
PLoS Negl Trop Dis · 2026 Jun · PMID 42371834 · Full text
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A rapid immunochromatographic test for antibody detection as a new tool for monitoring malaria caused by Plasmodium vivax.
Sampaio JR, Coelho FF, Soares IDS … +17 more , Oliveira JKA, Gazzinelli-Guimarães AC, Carvalho AF, Valiate BVS, Costa CM, Junqueira C, Silva AMV, Oliveira-Silva M, Pereira DB, de Pina-Costa A, Siqueira AM, Castro MC, Souza RP, Antonelli LRDV, Fernandes APSM, Gazzinelli RT, Almeida GG
PLoS Negl Trop Dis · 2026 Jun · PMID 42361195 · Full text
Eliminating malaria caused by Plasmodium vivax remains a challenge, especially in areas of low transmission, where the high proportion of asymptomatic and subpatent infections limits the effectiveness of national eradica...
Eliminating malaria caused by Plasmodium vivax remains a challenge, especially in areas of low transmission, where the high proportion of asymptomatic and subpatent infections limits the effectiveness of national eradication program control strategies. Antibody levels against parasite's antigens wane several months after treatment. Since the acquisition and maintenance of antimalarial humoral immunity depends on the infection, antibodies can serve as biomarkers of parasite exposure, emerging as a promising alternative for monitoring recent exposure to the parasite. We developed and validated a rapid diagnostic test that detects IgG (Ab-RDT) against two blood-stage antigens of P. vivax. The Ab-RDT identified a gradual decrease in antibody levels in treated individuals, suggesting that a positive test reflects recent exposure to the parasite or maintenance of infection. In agreement, a longitudinal study showed that a positive test, on Ab-RDT or ELISA, was strongly associated with the risk of subsequent detection of parasitemia by qPCR, highlighting the tests' usefulness in identifying individuals who were recently exposed or are more likely to be infected. The field performance of the Ab-RDT was 80.1% sensitivity and 89.4% specificity, using ELISA as a reference method, reinforcing the potential of antibody detection as a valuable tool to support malaria surveillance for P. vivax, especially for monitoring transmission in regions moving towards eradication, thereby enabling more strategic efforts in malaria control.
Contrasting geographic patterns of parasite and hantavirus diversity in the rodent Oligoryzomys longicaudatus (Rodentia, Cricetidae).
Brennan RN, Palma RE, Paulson SL … +2 more , Hernandez-Mazariegos WC, Escobar LE
PLoS Negl Trop Dis · 2026 Jun · PMID 42361152 · Full text
Host-parasite interactions arise from a complex interplay of evolutionary history, ecological context, and community structure, yet these dimensions are rarely examined together. Here, we introduce a unified framework th...
Host-parasite interactions arise from a complex interplay of evolutionary history, ecological context, and community structure, yet these dimensions are rarely examined together. Here, we introduce a unified framework that links the macroevolutionary processes shaping host-parasite associations with the microevolutionary dynamics driving intraspecific viral and host diversity. This approach reveals how evolutionary and ecological forces jointly structure parasite and viral diversity across a host's range. We used the hantavirus host Oligoryzomys longicaudatus in South America as a model system to explore this analytical framework. The objective of this study was to uncover potential factors contributing to parasite and viral diversity in this system in a framework that can be applied to other disease systems. Our data suggest that parasite richness peaks in environmentally optimal, central regions of the host's range, while hantavirus diversity peaks toward environmental and geographic margins. This dynamic connection among host ecology, parasite community turnover, and viral evolution illustrates how geographic and environmental variation influence host-parasite evolution. By bridging micro- and macroevolutionary signals, our analytical framework provides a biologically sound approach for describing host, parasite, and viral diversification in a changing world, and a foundation to explain how diseases emerge across changing landscapes.
Long-term disability outcomes in Hansen's disease: A 20-year comparative study of Lepromatous vs. Tuberculoid Leprosy.
Ma EJ, Adler BL, Armstrong AW … +1 more , Ochoa MT
PLoS Negl Trop Dis · 2026 Jun · PMID 42361034 · Full text
BACKGROUND: Leprosy remains an important cause of disability, even in non-endemic settings. Risk of neuropathy and functional impairment differs across the disease spectrum, yet contemporary U.S. data are limited. OBJECT...
BACKGROUND: Leprosy remains an important cause of disability, even in non-endemic settings. Risk of neuropathy and functional impairment differs across the disease spectrum, yet contemporary U.S. data are limited. OBJECTIVE: To compare disability-related outcomes among patients with lepromatous versus tuberculoid leprosy in a large U.S. electronic health record (EHR) network. METHODS: Using the TriNetX U.S. Collaborative Research Network (2005-2025), patients with lepromatous (ICD-10-CM A30.4-A30.5) and tuberculoid (A30.1-A30.2) leprosy were identified. Disability-related outcomes were defined using ICD-10-CM and CPT codes. Patients with prior disability were excluded to assess incident events. Cohorts were propensity score-matched (1:1) on demographics and comorbidities. Odds ratios (OR) and hazard ratios (HR) with 95% confidence intervals (CI) were calculated. RESULTS: A total of 341 lepromatous and 129 tuberculoid patients were identified (median follow-up 1,138 vs 1,021 days). Lepromatous leprosy was associated with higher risk of incident disability-related outcomes (OR 1.89, 95% CI 1.16-3.07). Kaplan-Meier analysis demonstrated lower outcome-free survival in the lepromatous cohort (HR 1.76, 95% CI 1.15-2.71). CONCLUSIONS: In this U.S.-based cohort, lepromatous leprosy was associated with greater disability-related morbidity compared to tuberculoid leprosy. However, meaningful risk was observed across both subtypes, supporting structured longitudinal follow-up for all patients.
Molecular detection and subtype characterization of Blastocystis in diarrheal outpatients in Shanghai, China: A case-control study.
Zhao W, Guan Y, Yu Q … +4 more , Zhang K, Zhang Z, Zhou H, Song B
PLoS Negl Trop Dis · 2026 Jun · PMID 42361025 · Full text
BACKGROUND: Blastocystis is the most prevalent enteric protozoan colonizing the human gastrointestinal tract, yet its clinical relevance and molecular epidemiological profiles in Shanghai, China's largest international m...
BACKGROUND: Blastocystis is the most prevalent enteric protozoan colonizing the human gastrointestinal tract, yet its clinical relevance and molecular epidemiological profiles in Shanghai, China's largest international megacity, remain unclear. The present study investigated the occurrence, subtype distribution, genetic diversity, and clinical associations of Blastocystis in diarrheal outpatients in Shanghai, China. METHODS: A case-control study was conducted with 370 fecal specimens (220 from diarrheal patients, 150 age- and sex-matched non-diarrheal healthy controls) collected between June 2023 and March 2026. Blastocystis was detected via PCR amplification of the small subunit ribosomal RNA (SSU rRNA) gene, with Sanger sequencing for subtype assignment. Statistical analyses were performed using categorical tests and logistic regression. RESULTS: The overall Blastocystis prevalence was 11.62% (43/370), significantly higher in diarrheal patients (16.8%; 37/220) than in controls (4.0%; 6/150, P < 0.001), with a higher detection rate in chronic (27.3%; 12/44) versus acute (14.2%; 25/176) diarrhea. Only two subtypes were identified: dominant ST3 (76.7%) and ST1 (23.3%). ST1 exhibited higher genetic diversity and showed an exploratory association with chronic diarrhea (P = 0.042, uncorrected for multiple testing). Age 7-18 years showed a borderline positive correlation with detection in diarrheal patients. CONCLUSIONS: This study found that Blastocystis detection was significantly correlated with diarrheal symptoms in the Shanghai outpatient population. ST3 was the dominant circulating subtype, and a potential association between ST1 and chronic diarrhea was identified, which requires confirmation in larger prospective studies. These results contribute to the regional molecular epidemiological database of Blastocystis and may inform clinical decision-making for patients with persistent unexplained diarrhea.
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