PLOS Neglected Tropical Diseases: New Articles

Identification of Leishmania spp. and Trypanosoma cruzi in bats captured in El Paso County, Texas

2026-04-03T14:00:00Z

by Juan C. Silva-Espinoza, Priscila S. G. Farani, Maria Fernanda Lopez, Edith Sandoval, Felipe Rodriguez, Kenneth A. Waldrup, Delfina C. Domínguez, Rosa A. Maldonado

Leishmania spp. and Trypanosoma cruzi are protozoan parasites that cause leishmaniasis and Chagas disease, respectively. In the United States, autochthonous transmission cycles of both Leishmania and T. cruzi have been documented, particularly in the southern and southwestern regions. Previous studies in El Paso, Texas, have identified dogs, cats, and several sylvatic mammals as infected hosts for these pathogens; however, the role of bats has remained largely unexplored. Here, we conducted a cross-sectional, observational study of 29 wild bats, opportunistically collected from domestic and peridomestic urban environments in El Paso, Texas, as part of local rabies surveillance. DNA extracted from available heart, spleen, skin, and lung tissues was analyzed by quantitative PCR targeting T. cruzi satellite DNA and Leishmania 18S rDNA, followed by DNA sequencing for confirmation. PCR-based molecular detection identified Leishmania spp. in six bats (24.1%) and Trypanosoma cruzi in thirteen bats (44.8%). DNA sequencing analysis confirmed the presence of parasite-specific DNA in four Leishmania-positive samples and twelve Trypanosoma cruzi-positive samples. Restriction fragment length polymorphism (RFLP) analysis showed that the digestion patterns of the T. cruzi samples differed from those observed in the TcBat reference control. However, given the limited characterization and known genetic variability of the TcBat lineage, as well as the constraints of PCR-RFLP–based typing, these findings do not conclusively exclude the possibility that the detected strains belong to the TcBat genotype. Co-detection of both parasites was detected in 3 out of 18 Tadarida brasiliensis specimens. Mapping of capture sites showed infected bats occurring in both urban and suburban areas of El Paso County. This study provides evidence of the molecular detection of Leishmania spp. and T. cruzi in bats from El Paso, Texas. These findings highlight bats as sylvatic hosts for medically important trypanosomatids in the U.S.–Mexico border region and emphasize the need for expanded surveillance to assess zoonotic risk and its environmental drivers.

Investigating impact of slash and clear vector control strategy on blackfly population and onchocerciasis transmission in a hotspot in Nigeria

2026-04-03T14:00:00Z

by Monsuru Adeleke, Olabanji Surakat, Bertram Nwoke, Kenneth Opara, Hayward Mafuyai, Zarat Iwalewa, Oluwadamilare Ganiu Dauda, Quadri Adeshina, Ilias Awoniyi, Murphy Nwoke, Friday Chikezie, Clement Yaro, Francisca Olamiju, Emmanuel Emukah, Chukwuemeka Makata, Olaitan Omitola, Ayodele Babalola, Benjamin Jacob

Background

The Edo–Ondo border remains a hotspot for onchocerciasis transmission and has been designated as a special intervention zone by Nigeria’s National Onchocerciasis Elimination Committee because of its persistent transmission and high blackfly biting rates. This study evaluated the effectiveness of the “slash-and-clear” vector control strategy and annual ivermectin distribution to interrupt transmission of Onchocerca volvulus in the area.

Methods

This study was implemented in two phases. Phase 1 (July–August 2023) involved slash-and-clear in four communities along the Ose River and its tributaries, while four others served as controls. Baseline biting rates were recorded for eight days, after which interventions were implemented in designated sites and fly collections continued for 29 days. Phase 2 (September 2023–June 2025) annual slash-and-clear was extended to 76 communities, including the original eight, where fly populations were continuously monitored. All collected blackflies were screened for O. volvulus infection using Ov ND5 qPCR pool screening.

Results

In Phase 1, biting rates in intervention communities decreased significantly by 51.1–91.9% (p < 0.05) along tributaries but increased in communities located directly on the Ose River or within 5 km. No significant changes were observed at the control sites. In Phase 2, sustained slash-and-clear across 76 communities resulted in significant reductions in blackfly densities, ranging from 39.7%–94.5%. Analysis of the flies showed infectivity for Ov ND5 genes in designated communities in the main Ose River and its tributaries indicating the presence of reservoirs of human Onchocerca volvulus microfilariae of onchocerciasis in the area.

Conclusion

The results of this study demonstrate the possibility of significant reduction in Simulium damnosum complex biting rates with sustained slash-and-clear activity in the region (most especially the tributaries). Therefore, we recommend further studies to determine drivers of transmission aside from flies to fast-track the elimination of onchocerciasis in the area.

Leishmania amazonensis amastigotes invade non-phagocytic cells via highly localized parasite-induced actin remodeling

2026-04-03T14:00:00Z

by Thamires Queiroz-Oliveira, Laura Valéria Rios-Barros, Anna Luiza Silva-Moreira, Isadora Vieira Santos-Brasil, Julyanna Oliveira-Castro, Juliana Almeida-Silva, Marcos André Vannier-Santos, Jane Lima-Santos, Maria Fátima Horta, Thiago Castro-Gomes

Intracellular parasites are pathogens that must invade and persist within host cells. In the case of Leishmania spp., it is generally assumed that the parasite must be phagocytosed to further establish residence within professional phagocytic cells. However, several studies report the presence of Leishmania spp. in non-phagocytic cells, highlighting their ability to enter cells independently of classical phagocytosis. Indeed, we have recently demonstrated that promastigotes, the infective form transmitted to hosts during the bite of the insect vector, subvert a lysosome-exocytosis-dependent membrane repair pathway to invade fibroblasts. Here, we investigate the invasion of non-phagocytic cells by L. amazonensis amastigotes, the infective form directly responsible for host-to-vector transmission, disease generation and parasite dissemination during infection in humans and other mammalian hosts. Our results show that amastigotes rapidly induce their entry into cells lacking classical phagocytic capability, where they survive, multiply, and persist. Invasion depends on parasite-induced actin remodeling confined to the parasite-host plasma membrane contact site, with localized recruitment of Rho GTPases that fuel actin polymerization at invasion foci. Our findings highlight the remarkable ability of Leishmania amastigotes to induce their own internalization into virtually any cell type, bypassing the need for conventional phagocytosis. This property may profoundly influence parasite biology by enabling amastigotes to cross cellular barriers, disseminate, and silently establish infection in diverse host cells. Importantly, when considering non-phagocytic cells, our results demonstrate that Leishmania amazonensis employs distinct, stage-specific invasion mechanisms: promastigotes co-opt host cell lysosomes, whereas amastigotes depend on F-actin dynamics.

In silico design of a novel multi-epitope mRNA vaccine candidate for BtHKU5-CoV-2 using immunoinformatics

2026-04-03T14:00:00Z

by Ningze Zheng, Yingqi Xu

Bat HKU5-CoV-2 (BtHKU5-CoV-2), a recently discovered bat-infecting merbecovirus, was found to infect human cell lines by utilizing the human angiotensin-converting enzyme 2 (ACE2) receptor, similar to SARS-CoV-2, which caused millions of deaths. Moreover, its broad host tropism has raised significant concerns about potential human spillover risk. Therefore, there is an urgent need to develop vaccines to combat the potential outbreak of BtHKU5-CoV-2. However, research focusing on BtHKU5-CoV-2 remains limited. In this study, we designed a novel multi-epitope vaccine for BtHKU5-CoV-2 using an immunoinformatics approach. Eight cytotoxic T lymphocyte (CTL) epitopes, seven helper T lymphocyte (HTL) epitopes, and five linear B lymphocyte (LBL) epitopes were screened from the spike glycoprotein of BtHKU5-CoV-2. The selected epitopes were joined together with appropriate linkers, and β-defensin II and MHC I-targeting domain (MITD) were incorporated into the construct to enhance vaccine immunogenicity. In silico analyses suggested that the designed vaccine may have favorable predicted antigenicity and immunogenicity while being non-toxic and non-allergenic. The tertiary structure of the multi-epitope vaccine was modeled and refined, and its structural plausibility was evaluated using in silico quality metrics. Molecular docking studies suggested plausible interaction modes between the vaccine construct and Toll-like receptor 2 (TLR2) and TLR4. Moreover, the mRNA was predicted to show potential interaction modes with TLR3, TLR7, and TLR8 receptors. Additionally, in silico immune simulations suggested that vaccination may elicit humoral and cellular immune responses. Collectively, these computational results suggest that the proposed mRNA vaccine is a potential candidate for BtHKU5-CoV-2. However, further experiments are necessary to validate its protective efficacy.

Glycosomal Aquaglyceroporin 1 dual role in iron homeostasis and antimony susceptibility in Leishmania amazonensis

2026-04-02T14:00:00Z

by Romario Lopes Boy, Ricardo Andrade Zampieri, Juliana Ide Aoki, Adriano Cappellazzo Coelho, Lucile Maria Floeter-Winter, Maria Fernanda Laranjeira-Silva

Leishmania parasites cause a spectrum of diseases known as leishmaniases and must acquire nutrients like iron while surviving host defenses. Aquaglyceroporin 1 (AQP1) is a membrane channel that, in L. major, localizes to the flagellum and mediates antimony uptake and cell-volume regulation. Here, we show that in L. amazonensis AQP1 is instead targeted to glycosomes and that its expression is modulated by iron availability. A CRISPR-Cas9–mediated knockout of AQP1 in L. amazonensis revealed its multifunctional importance. AQP1-null promastigotes displayed a significant growth defect, particularly under iron-depleted conditions, and were impaired in regulating cell volume under osmotic stress. The mutant parasites contained approximately 50% less intracellular iron than wild-type cells and showed an increase in total superoxide dismutase activity, underscoring a role for AQP1 in iron homeostasis and oxidative stress management. AQP1 deletion also markedly reduced virulence in murine macrophages and in infected mice. Strikingly, loss of AQP1 increased resistance to trivalent antimony (Sb^III), a first-line antileishmanial drug. AQP1-knockout promastigotes showed a 70% increase in Sb^III IC₅₀ and accumulated more Sb intracellularly than wild-type, suggesting an altered antimony handling. Altogether, L. amazonensis AQP1 is a glycosomal protein that links iron metabolism, osmoregulation, and antimony susceptibility. Its glycosomal targeting and multifaceted roles differ from those of AQP1 orthologs in other Leishmania species. These findings suggest the existence of additional antimony uptake mechanisms beyond AQP1, with implications for understanding drug resistance.

Advances in vaccine development through the controlled human infection models for hookworm and schistosomiasis

2026-04-02T14:00:00Z

by Marie-Astrid Hoogerwerf, Moses Egesa, Selidgji Todagbe Agnandji, Alex Loukas, Meta Roestenberg

Controlled human infection models can play an important role in vaccine development, particularly for neglected tropical diseases such as helminth infections. Currently, controlled infection models have been established for schistosomiasis and hookworm. This review highlights the developments in the controlled human schistosomiasis infection model (CHI-S) and the controlled human hookworm infection model (CHHI) and their contributions to vaccine development. In general, both models are considered safe and well-tolerated. Measures to decrease risk of potential adverse events were taken when developing the models. For both models, production of challenge agents follows the principles of Good Manufacturing Practice. Both models have proven to reliably detect infection and can be used to assess efficacy of immunization strategies. While hookworms and schistosomes are both helminths, the controlled human infection (CHI)-studies have also highlighted differences between these pathogens. Notably, schistosomiasis seems to induce more, dose-dependent, systemic symptoms, whereas in hookworm models skin symptoms are much more prominent. Infection levels for schistosomiasis are therefore limited and lower than those usually seen in endemic populations, whereas for hookworm it is possible to reach levels comparable to mild-moderate intensity infection in the field. Host responses to short-term infection were also different: short-term schistosome infection induced immune-tolerance, whereas short-term infection with hookworm larvae seems to induce a more pro-inflammatory response compared to that seen in the adult worms. Most studies have been performed in naïve non-endemic populations, however, currently the models are being expanded to endemic areas. This has raised new questions around the impact of non-native strains of parasites or vectors to the endemic parasite strains and the environment. Studies in endemic areas, however, will significantly contribute towards understanding the immunology of these helminth infections in pre-exposed individuals. In general, the success of these established models is encouraging to the further development of controlled human helminth infection models.

Oropouche virus outbreaks in northeast Brazil between 2024–25 are characterized by sustained transmission and spread to newly affected areas

2026-04-01T14:00:00Z

by Elverson Soares de Melo, Sophia Maria Dantas da Silva, Gustavo Barbosa de Lima, Adalúcia da Silva, Alexandre Freitas da Silva, Verônica Gomes da Silva, Elisa de Almeida Neves Azevedo, Letícia Welter Rother, Keilla Maria Paz e Silva, Diego Arruda Falcão, Andreza Pâmela Vasconcelos, Mayara Matias de Oliveira Marques da Costa, Eduardo Augusto Duque Bezerra, Thiago Franco de Oliveira Carneiro, Erik Matthaus de Lima Paiva, Janaina Correia Oliveira, Matheus Filgueira Bezerra, Marcelo Henrique Santos Paiva, Bartolomeu Acioli-Santos, Clarice Neuenschwander Lins de Morais, Tulio de Lima Campos, Gabriel da Luz Wallau

Oropouche virus (OROV) has recently expanded in Brazil, establishing transmission in non-endemic regions. This study aims to integrate epidemiological and molecular data to investigate OROV spread in Northeast (NE) Brazil between 2024 and 2025. OROV cases were analyzed regarding ecological risk factors and geographical clustering. Additionally, we sequenced 65 new OROV genomes from the Northeast states of Pernambuco, Paraíba, and Sergipe to infer the virus’s spatiotemporal dynamics in NE Brazil. A total of 2,806 confirmed cases were reported between March 2024 and April 2025, affecting 170 municipalities across eight out of nine NE states, with highly heterogeneous incidence. An ecological shift was observed, with OROV transmission moving from Atlantic Forest areas in 2024 to humid Caatinga zones in 2025. Phylogenetic reconstruction revealed multiple independent viral introductions in Northeast in 2024, including two in Pernambuco. The first, originating from the central Amazonas, became the main driver of local transmission and subsequently spread to Sergipe and Paraíba, causing outbreaks in 2024 and 2025, respectively. The second introduction remained restricted within Pernambuco. While several Northeast municipalities reported high OROV incidence, Jaqueira (Pernambuco) emerged as a key hub for regional viral spread. OROV showed sustained transmission in the region over a two-year period, characterized by marked spatiotemporal displacement consistent with short-lived, rapidly spreading outbreaks, followed by cryptic transmission and subsequent dissemination to new areas, ultimately driving renewed intense outbreaks.

Addressing the elephant in the room: Proceedings of the third annual Dengue Endgame Summit

2026-04-01T14:00:00Z

by Lauren E. Bahr, Alan L. Rothman, Alan D. T. Barrett, Darunee Buddhari, Derek A. T. Cummings, Rebecca C. Christofferson, Albert I. Ko, Eng Eong Ooi, Kathryn B. Anderson, Stephen J. Thomas, Adam T. Waickman

Dengue is a disease caused by four serologically and genetically distinct orthoflaviviruses spread by mosquitoes. It is the largest arthropod-borne viral disease in the world with millions of human cases each year. The third annual Dengue Endgame Summit was convened in Syracuse, New York, over August 12–14, 2025, to discuss the current state of dengue, global dengue control efforts, and paths towards achieving sustained and effective dengue control. The event brought together 181 participants from 48 institutions across 11 countries to address current dengue outbreaks, next-generation mosquito vector interventions, vaccine and antiviral development, immune correlates of protection, and human challenge models. Four key themes emerged from the in-depth and nuanced discussions at the summit: (1) dengue control will require globally coordinated but locally tailored approaches that account for regional transmission differences and diverse circulating viral serotypes and genotypes; (2) the evolving dengue burden necessitates the strategic deployment of countermeasures, including vaccines, antivirals, and vector control, matched to local epidemiology; (3) longstanding dogma surrounding dengue immunopathogenesis and immune correlates of protection should be systematically reevaluated in light of advances in our understanding of cellular immunity, trained innate immunity, and the interplay of multiple components of the immune response; and (4) sustained progress depends on multisectoral collaboration, adequate financial resources, political commitment, and integration with broader vector-borne disease control efforts. These discussions highlighted both the complexity of dengue control and the diverse opportunities for accelerating progress toward a dengue endgame.

Cost effectiveness of the Texas wildlife rabies Border Maintenance Zone

2026-04-01T14:00:00Z

by Stephanie Shwiff, Glenn Swanson, Steven Shwiff, Mike Bodenchuk, Joanne Maki

Rabies prevention in the United States (US) relies on a robust public health infrastructure that includes pet vaccination, post-exposure prophylaxis (PEP), and wildlife surveillance, costing $245–$510 million annually but saving over $1 billion in avoided healthcare expenditures. While canine rabies has been eliminated from the US, wildlife reservoirs continue to pose a zoonotic threat, particularly bats, skunks, raccoons, and foxes. Oral rabies vaccination (ORV) programs targeting coyotes, foxes, and raccoons have demonstrated significant public health and economic benefits across multiple states, with benefit-cost ratios consistently above 1.0. In 2023, the Texas Oral Rabies Vaccination Program (TX-ORVP) reduced bait density within its ORV program’s barrier maintenance zone (BMZ) to lower fixed costs. This study applies cost-effectiveness analysis (CEA) to assess whether these reductions remain economically viable under scenarios involving increased variable costs. Three scenarios were modeled: (1) enhanced surveillance without contingency actions, (2) rural incursions requiring contingency actions, and (3) comprehensive breaches involving surveillance, contingency actions, and increased PEP. Results indicate that surveillance costs could increase by up to 155% before negating savings, but any scenario requiring contingency actions renders the BMZ2023 cost-inefficient compared to pre-2023 practices. These findings underscore that while reduced bait density may appear cost-saving, heightened risk of rabies incursions can quickly erode economic sustainability. Sustained investment in wildlife rabies ORV programs is necessary for effective and efficient long-term rabies control and public health protection.

Long-term spatio-temporal trends in burden of fungal skin diseases in middle-aged and elderly people from 1990 to 2021

2026-04-01T14:00:00Z

by Qinglian Qin, Yuyuan Huang, Zedan Yang, Xiaoting Wei, Tongxue Qin, Jinming Su, Jie Liu, Rongfeng Chen, Wudi Wei, Zongxiang Yuan, Jingzhen Lai, Li Ye, Hao Liang, Junjun Jiang

Background

As a high incidence group, the elderly face the burden of fungal skin diseases, which has remained poorly quantified. This study aims to analyse the spatiotemporal trends in the burden of fungal skin diseases in middle-aged and elderly people from 1990 to 2021.

Methods

Data were obtained from the Global Burden of Disease (GBD) Study 2021. This study analysed incident cases, prevalent cases, disability-adjusted life years (DALYs), and their corresponding rates for fungal skin diseases in middle-aged and elderly people stratified by sex, age, socio-demographic index (SDI), GBD regions, and countries. Average annual percent change (AAPC) was calculated to assess temporal trends in the burden of fungal skin diseases.

Results

From 1990 to 2021, the global incidence, prevalence, and DALYs rates of fungal skin diseases in middle-aged and elderly people were consistently higher than those in the entire population. Globally, incident cases, prevalent cases, and DALYs of fungal skin diseases in middle-aged and elderly people increased by 124.09%, 124.13%, and 123.26%, respectively. In 2021, the incidence, prevalence, and DALYs rates were 38255.44 (95% uncertainty interval [UI]: 32832.61-44492.76), 12186.46 (95% UI: 10721.21-14030.06), and 64.66 (95% UI: 26.34-133.26) per 100,000 population, respectively. From 1990 to 2021, the incidence, prevalence, and DALYs rates exhibited overall upward trends, with AAPCs of 4.12% (95% confidence interval [CI]: 3.04%-5.20%), 4.18% (95% CI: 3.11%-5.24%), and 2.89% (95% CI: 1.89%-3.89%), respectively. Geographically, the highest burden was concentrated in Andean Latin America, Australasia, and Western Europe.

Conclusions

The global burden of fungal skin diseases in middle-aged and elderly people has increased over the past three decades, with significant disparities across sexes, SDI levels, regions, and countries. Targeted public health interventions and resource allocation are required to reduce the burden of fungal skin diseases in this vulnerable population.

Impact of inactivation methods on biosafety and antigen reactivity of Brucella melitensis from the perspective of Astral-DIA proteomics based on antibody immunoprecipitation mass spectrometry

2026-04-01T14:00:00Z

by Yijian Liu, Jiazhen Ge, Guodong Song, Pengcheng Gao, Mengzhu Qi, Wenhao Wang, Yingying Xie, Ziqing Wang, Renge Li, Yuefeng Chu, Fuying Zheng

Effective Brucella inactivation is essential for safe vaccine development, diagnostics, and sample handling, particularly in resource-limited regions without high-level biosafety facilities. This study evaluated heat (80°C/95°C, 10–20 min) and formaldehyde (0.4%/0.6%, 48–72 h) inactivation using the Rev.1 vaccine strain and three Brucella melitensis field isolates from Gansu (GS-XG1, GS-SN2, GS-MQ3). All field isolates were collected from a single geographic region (Gansu, China), which should be considered when interpreting the broader geographic generalizability of the findings. Complete inactivation of Rev.1 was achieved by heating at 80°C/95°C for 20 min or 0.6% formaldehyde for 48–72 h, with superior immunoreactivity compared to phenol inactivation as confirmed by ELISA and Western Blot. Field isolates showed greater resistance, surviving 80°C for 20 min and 0.4% formaldehyde for 72 h, requiring stricter conditions (95°C for 20 min or 0.6% formaldehyde for 72 h). Antibody immunoprecipitation-based Orbitrap Astral DIA proteomics covered ~60% of the proteome (~2,000/3,300 proteins) and identified 256, 311, and 318 differentially detected proteins (DDPs) for 80°C vs. 95°C heat, 48 h vs. 72 h formaldehyde, and heat vs. formaldehyde comparisons, respectively. These DDPs reflect inactivation-induced changes in protein detectability due to denaturation, aggregation, or cross-linking, rather than de novo gene expression (confirmed by metabolic inhibition assays showing complete absence of metabolic activity). Gene Ontology and KEGG analyses revealed that heat inactivation enriched cellular structure proteins while downregulating metabolic pathways, with 95°C potentially disrupting conformational epitopes. Formaldehyde treatment for 48 h better preserved soluble antigens and epitopes of ribosomal and regulatory proteins, whereas 72 h treatment caused greater cell envelope disruption. Protein-protein interaction networks indicated that heat inactivation enhanced immunoreactivity of membrane and stress proteins, making it suitable for targeted epitope studies, while formaldehyde preserved broader epitopes, benefiting whole-cell vaccines and multi-epitope screening. Inactivation protocols should be tailored to strain characteristics and intended applications. Astral-DIA proteomics provides molecular insights into antigenicity preservation, guiding future research on protein stability and epitope dynamics for improved brucellosis control.

Impact of projected climate and socioeconomic scenarios on state-wise annual dengue incidence in India using ensemble models

2026-03-31T14:00:00Z

by Avik Kumar Sam, Ipsita Pal Bhowmick, Harish C. Phuleria

India, the world's most populous country, has reported over 1 million dengue cases and ~3,000 deaths between 2007 and 2022. With the annual state-wise data, we examined the spatiotemporal distribution of dengue in 28 states and eight union territories for 16 years across India. Using state-wise data on climatic variables, socio-economic inequities and land-use land-cover changes, potential determinants for the state-wise transmission were identified through a supervised regression model. The identified determinants were then mapped to various novel developmental scenarios, which were designed based on the existing shared socio-economic pathways. To estimate the dengue burden for each scenario, ensemble models of XGBoost and Gradient Boosting regression algorithms were developed. We note that 73% of the cases occurred between 2016 and 2022, highlighting a significant increase in dengue outbreaks across the country. All Himalayan states, which witness colder temperatures, have witnessed a growth in cases: Himachal Pradesh reported 168 times more cases between 2016 and 2022 than those observed between 2007 and 2015. The models suggest that dengue incidences may potentially change under future socioeconomic burden, although projections are associated with substantial uncertainty and should be interpreted as potential trajectories rather than definitive forecasts. We estimate that development focused on sustainability (874.2 per 10 million; 95% CI: 535.4, 1212.9) and fossil fuels (888.02 per 10 million; 95% CI: 521.2, 1254.9) will relatively cause a lesser burden across the country by the 2030s. Southern states are projected to have higher dengue outbreaks, while Jharkhand, a historically malaria-endemic state, is estimated to report twice as many cases in 2050 as what was reported in 2022. Given the uncertainty associated with long-term projections, public health strategies may benefit from adaptive approaches which are backed by climate- and socioeconomic-data integrated early warning systems that can respond to evolving climatic and socioeconomic conditions influencing dengue transmission. Our study provides insights into how the spread of dengue will change with varying models of socio-economic development, which highlights the spatial heterogeneity in potential future dengue risk, suggesting that resource allocation and surveillance efforts may benefit from region-specific prioritisation instead of a uniform policy.

Assessment of the role of Haemophilus ducreyi coinfection on outcomes of Yaws treatment in the southwestern part of Ghana

2026-03-30T14:00:00Z

by Abigail Agbanyo, Michael Ntiamoah Oppong, Dzifa Kofi Ahiatrogah, Ruth Dede Tuwor, Clement Tettey, Joseph Azabire, Owusu Boakye Yiadom, Dennis Odai Laryea, Alex Owusu-Ofori, Richard Odame Phillips, Yaw Ampem Amoako

Background

Yaws, caused by Treponema pallidum subsp. pertenue (TP) is targeted for eradication by 2030 under the World Health Organization’s (WHO) initiative, which relies on mass drug administration (MDA) of azithromycin. Evidence of persistent lesions after treatment has been reported. While the occurrences of Haemophilus ducreyi (HD) in yaws-like lesions has been widely documented, there is limited evidence regarding its influence on treatment outcomes assessed at the WHO-recommended 4-week follow-up. In this study, we sought to detect the occurrence of H. ducreyi in yaws-confirmed cases and assess its influence on treatment outcomes.

Methodology

We conducted a prospective cohort study of school children from Wassa Amenfi East and Aowin Districts in Ghana. A total of 46 Dual Path Platform (DPP) positive yaws cases were subjected to PCR analysis to determine the aetiological agents, including T. pallidum and/or H. ducreyi. Treatment was with a single dose of oral azithromycin and outcomes were evaluated 4 weeks post-treatment, assessing clinical resolution and time to healing, with results stratified by the identified aetiological agents.

Findings

Of the 46 participants tested, 18/46 (39%) were positive for HD, 6 (13%) were TP positive, 3 (7%) were positive for TP/HD, and 19 (41%) were negative for both pathogens tested. Healing rate was 80.4% (95% Confidence Interval [CI], 73.9–95.5) for all cases; 72.2% (95% CI: 57.0–93.4) for HD only, 83.3% (95% CI: 43.6–97.0) for TP only, 100% (95% CI: 43.9–100) for TP/HD, and 84.2% (95% CI: 62.4–94.5) for negative cases. Complete healing was generally observed by day 15–20.

Conclusion

These results support the ongoing use of a single dose azithromycin in yaws elimination programmes, as evidenced by the healing rates observed. Nonetheless, greater focus should be directed toward improving diagnostic and treatment approaches for individual patients. Further research is necessary to better understand the aetiology of cutaneous ulcers in yaws-endemic regions.

Advanced machine learning approaches for predicting Neglected Tropical Disease co-endemicity in Kenya: A focus on soil-transmitted helminths, schistosomiasis, and lymphatic filariasis

2026-03-30T14:00:00Z

by Nkuba Nyerere, Damaris Felistus Mulwa

Background

Neglected Tropical Diseases (NTDs) affect 1.5 billion people worldwide with 39% of the global burden occurring in Africa. In Kenya, NTDs remain endemic despite control efforts, with co-endemicity of soil-transmitted helminths (STH), schistosomiasis (SCH), and lymphatic filariasis (LF) complicating intervention strategies. This study developed machine learning models to predict high-risk co-endemic areas using demographic and Water, Sanitation, and Hygiene (WASH) indicators.

Methodology

The study analyzed Kenya’s 2022 NTD co-endemicity data from the Expanded Special Project for Elimination of Neglected Tropical Diseases, incorporating WASH and population variables. Three machine learning algorithms, Random Forest, Gradient Boosting Machine, and Extreme Gradient Boosting (XGBoost) were trained to classify regions by STH prevalence levels and co-endemicity status. Model performance was evaluated using cross-validation, Receiver Operating Characteristic – Area under the Curve (AUC) and variable importance analysis.

Results

The RF model achieved the highest predictive performance (AUC = 0.70), followed by XGBoost (AUC = 0.66) and GBM (AUC = 0.62). Key predictors included improved sanitation access (mean importance score: 0.24), population density (0.21), and co-endemicity with LF/SCH (0.18). Spatial analysis identified Eastern and North-Eastern Kenya as persistent hotspots, correlating with low WASH coverage (<40%).

Conclusion

Machine learning models effectively identified the high-risk NTD co-endemic areas in Kenya, with RF outperforming other models. These findings support targeted interventions integrating WASH improvements with mass drug administration in identified hotspots. We propose a real-time dashboard for dynamic risk mapping to optimize resource allocation; a strategy aligned with Kenya’s NTD Elimination Strategic Plan 2030.

Paralytic rabies outbreak mimicking guillain–Barré syndrome in French Amazonia

2026-03-30T14:00:00Z

by Nathalie Deschamps, Claire Mayence, Perrine Parize, Maylis Douine, Clémentine Montagnac, Stephanie Houcke, Loïc Epelboin, Amina Nasri, Felix Djossou, Florence Larrous, Katherine Worsley-Tonks, Karim Hamiche, Alessandra Monaya, Cyril Rousseau, Samuel Gavohedo, Kinan Drak Alsibai, Magalie Demar, Bertrand de Toffol, Hervé Bourhy, Hatem Kallel

Background

In the Amazonian region, vampire bats are the primary reservoir of rabies virus, causing sporadic and lethal human rabies cases that often remain unnoticed. Managing human cases in this region is challenging and further complicated by atypical clinical forms and the potential exposure to various toxic compounds, particularly among gold miners.

Methods

We carried out clinical, electrical, biological and histological analysis of concurrent cases of progressive motor neuronopathy and fatal encephalitis in a context of regular exposure to bat bites of gold miners living in a small and remote gold mine camp in Amazonia, in French Guiana, South America.

Findings

We analyzed a spatio-temporal cluster of three suspected rabies cases in 2024 with a fatal outcome, with concomitant onset of acute bilateral lower-limb paralysis without demyelination, two of which occurred presumably two weeks after a bat-bite. Electroneuromyography suggested the involvement of the anterior horn of the spinal cord, as described in furious forms of rabies. None of the cases exhibited other cardinal signs of the furious form. Confirmation of rabies was obtained for them on sera and brain biopsies collected ante- and post-mortem respectively.

Interpretation

The concurrent occurrence of disease, the axonal motor neuropathy mimicking the motor form of Guillain Barré syndrome in the context of paralytic rabies, lead to diagnostic-wandering. This underscores the importance of thinking about vampire bat rabies virus in the presence of any atypical neurological picture in patients living in exposed areas in Latin America.

Reduced cytochrome P-450 (CYP) 2D6 activity and Plasmodium vivax malaria risk in Amazonians: A retrospective, population-based cohort study

2026-03-27T14:00:00Z

by Rodrigo M. Corder, Maria Carolina S. B. Puça, Carlos A. Prete, Winni A. Ladeia, Priscila T. Rodrigues, Igor C. Johansen, Tais Nobrega de Sousa, Marcelo U. Ferreira, on behalf of the Mâncio Lima Cohort Study Working Group

Background

Primaquine (PQ) is the only widely available drug that eliminates latent hypnozoites, thereby preventing relapses of Plasmodium vivax malaria. Because PQ biotransformation mediated by the cytochrome P-450 (CYP) isoenzyme CYP2D6 is required for therapeutic activity, patients with reduced CYP2D6 activity can experience relapse despite treatment. The minimum level of CYP2D6 activity for adequate anti-relapse PQ efficacy is unknown.

Methods and findings

We conducted a retrospective, population-based cohort study in the main malaria hotspot of Brazil. We fitted time-to-event data from cohort participants who experienced vivax malaria, using Cox proportional hazards models, to explore how genotype-determined CYP2D6 activity, expressed as activity scores (AS), modulates the risk of P. vivax recurrence within 6 months after treatment with chloroquine and PQ (total dose, 3.5 mg/kg). We analyzed community-wide P. vivax malaria incidence data, using a multivariable negative binomial regression model, to quantify the impact of reduced CYP2D6 activity on the overall risk of vivax malaria, whether from relapses or new infections. Among 466 P. vivax-infected cohort participants, those with null/low CYP2D6 activity (AS ≤ 0.25), but not participants with intermediate CYP2D6 activity (AS from 0.5 to 1.0), had twice the risk of recurrence compared to an AS > 1.0 (hazard ratio = 2.22, P = 0.004). However, vivax malaria incidence did not differ significantly across CYP2D6 activity levels during 5 years of follow-up of 997 Amazonians exposed to intense transmission (mean, 26.6 vivax malaria cases/100 person-years). These findings suggest that the excess of relapses among people with severely reduced CYP2D6 activity adds relatively little to the overall burden of vivax malaria episodes.

Conclusion

Amazonians with an AS ≤ 0.25, but not necessarily those with intermediate CYP2D6 activity, have a greater risk of recurrence after a PQ-treated P. vivax infection and require alternative relapse suppression regimens for the radical cure of vivax malaria.

Delivery of canine rabies vaccination programme in Kutupalong-Balukhali refugee camps, Cox’s Bazar, Bangladesh

2026-03-27T14:00:00Z

by Luke Gamble, Karlette A. Fernandes, Keiichiro Tazawa, Rubaiya Ahmad, Kamrul Islam, James Hood, Bernadette Abela, Balaji Chandrashekar, Frederic Lohr, Ryan M. Wallace, Tim Parkin, Andrew D. Gibson, Catherine Swedberg

Background

Rabies causes over 60,000 deaths annually, primarily among children, with dog bites responsible for nearly all human cases. Although mass dog vaccination is effective in low-resource settings, structured campaigns have rarely been implemented in refugee camps, where unmanaged dog populations and limited access to post-exposure prophylaxis heighten rabies risk. This study aimed to demonstrate the possibility of delivering systematic mass dog vaccination within a short operational timeframe in a humanitarian setting and to assess community perceptions of rabies risk and prevention.

Methodology/principal findings

In May 2025, a four-day mass dog vaccination campaign was conducted across the Kutupalong-Balukhali refugee settlement in Cox’s Bazar, Bangladesh, with real-time data collection to guide operations. Post-vaccination dog sight surveys assessed operational coverage, while community surveys evaluated knowledge, attitudes and practices (KAP) regarding rabies. Of the 2,275 dogs encountered, 1,781 (78.3%) were vaccinated, with 86.4% classified as unowned community dogs. The overall proportion of marked dogs across all surveyed zones was 71.5% (95% CI: 66.8–75.9%). In the community survey, 34.6% of 1,311 adult respondents (gender-adjusted) had heard of rabies, and 41.2% correctly identified dog bites as the primary route of transmission. Regarding appropriate post-bite care, 25.9% knew to both wash the wound and seek medical care. Approximately 8.7% of households experienced a dog bite in the preceding year, corresponding to a minimum annual incidence of 13.3 bites per 1,000 persons, equating to over 15,000 bites per year.

Conclusions/significance

This study represents the first structured mass dog vaccination campaign in a refugee setting, demonstrating that rabies control can be effectively implemented even in complex humanitarian contexts. The campaign’s success offers a replicable model for integrating zoonotic disease prevention into emergency health responses, underscoring the critical need to safeguard displaced populations from preventable diseases.

Three decades of discovery: An overview of Hendra virus, the original Henipavirus

2026-03-27T14:00:00Z

by Kim Halpin, Raúl Gómez Román

Hendra virus (HeV) emerged in Australia in 1994, causing a devastating outbreak among horses in Brisbane with spread to humans, resulting in one death. This nonsegmented, negative-stranded RNA virus belongs to the family Paramyxoviridae and represents the first zoonotic paramyxovirus isolated from bats. Flying foxes (genus Pteropus) serve as the natural reservoir, with all four mainland Australian species carrying antibodies with no apparent disease. HeV initiates infection by binding ephrin-B2 receptors on vascular endothelial cells, driving characteristic pathology involving vasculitis, thrombosis, and neurological complications. Horses are amplifying hosts, shedding virus abundantly in respiratory secretions and posing transmission risks to humans during invasive procedures. To date, seven confirmed human infections have been documented, with a 57% fatality rate, presenting as severe respiratory disease or progressive encephalitis. Two genetic variants are now recognized: the original HeV genotype 1 and the emerging HeV genotype 2, identified in limited equine cases. Recent surveillance of bat roosts revealed substantial viral diversity, with peak shedding occurring during winter—coinciding with equine spillover peaks. Prevention integrates multiple strategies: the licensed equine vaccine Equivac which provides One Health protection for both horses and human contacts; biosecurity measures including proper PPE; and habitat restoration to reduce nutritional stress in bat populations. Emerging therapeutics include monoclonal antibodies, with m102.4 showing cross-protective activity against both HeV and the closely related Nipah virus. No licensed human vaccines currently exist, though candidates are in development. Future prevention strategies increasingly recognize the importance of Indigenous-led conservation approaches alongside biomedical interventions. This review will focus on the history of HeV, virus replication and diversity, epidemiology, clinical manifestations, diagnosis, treatment, prevention, as well as ecological and interdisciplinary countermeasures.

Genomic analysis of human-infecting Leptospira borgpetersenii isolates in Sri Lanka: Expanded PF07598 gene family repertoire and less genome reduction than bovine isolates

2026-03-27T14:00:00Z

by Indika Senavirathna, Dinesha Jayasundara, Janith Warnasekara, Suneth Agampodi, Ellie J. Putz, Jarlath E. Nally, Darrell O. Bayles, Reetika Chaurasia, Joseph M. Vinetz

Leptospira borgpetersenii is a causative agent of human leptospirosis, with the potential to lead to severe disease manifestations. The first published analysis of L. borgpetersenii, performed on two strains of serovar Hardjo (L550 and JB197), suggested that the L. borgpetersenii genome is in the process of genome decay with functional consequences leading to a more obligately host-dependent life cycle. Whole genome analysis has only been carried out on few strains of L. borgpetersenii, with limited closed genomes and comprehensive analyses. Herein we report the complete, circularized genomes of seven non-typeable Leptospira borgpetersenii isolates from human leptospirosis patients in Sri Lanka. These isolates (all identified as strain ST144) were found to be nearly identical by whole genome analysis; serotyping with serogroup-specific reference antisera was unreactive, suggesting that these are members of a novel serogroup/serovar. We show that the L. borgpetersenii isolated from humans in Sri Lanka show less genomic decay than previously reported isolates: fewer pseudogenes (N = 141) and insertion sequence (IS) elements (N = 46) compared to N = 248, N = 270, and N = 400 pseudogenes, and N = 121 and N = 116 IS elements in other published L. borgpetersenii Hardjo genomes (strains L550, JB197 and TC112). Compared to previously published L. borgpetersenii whole genome analyses showing two or three VM proteins in L. borgpetersenii isolates from cattle, rats and humans, we found that all of the human L. borgpetersenii isolates from Sri Lanka, including previously reported serovar Piyasena, have four encoded VM proteins, one ortholog of L. interrogans Copenhageni LIC12339 (LA1402) and three orthologs of LIC12844 (LA0589). Our findings of fewer pseudogenes, IS elements, and expansion of the LIC12844 homologs of the PF07598 family in these human isolates suggests that this newly identified L. borgpetersenii serovar from Sri Lanka has unique pathogenicity. Comparative genome analysis and experimental studies of these L. borgpetersenii isolates offer deeper insights into the molecular and cellular mechanisms of leptospirosis pathogenesis.

A systematic review of adverse effects associated with systemic corticosteroids in the management of leprosy

2026-03-26T14:00:00Z

by Andie I. Lun, Barbara de Barros, Stephen L. Walker

Background

Leprosy is a chronic infectious disease caused by Mycobacterium leprae (M. leprae) and Mycobacterium lepromatosis (M. lepromatosis), primarily affecting the skin and peripheral nervous system. Leprosy is complicated by immune-mediated reactions which are risk factors for nerve damage and disability. Systemic corticosteroids are the mainstay of therapy; however, prolonged use in chronic or recurrent reactions carries significant risks but the evidence on the short- and long-term adverse effects of corticosteroids in leprosy is limited. We conducted a systematic review to evaluate corticosteroid-associated adverse effects in leprosy affected individuals.

Methodology

Eight electronic databases were searched (including PubMed, Embase and LILACS) without language or year restriction for studies reporting adverse effects associated with systemic corticosteroid use in individuals with leprosy. Eligible studies included randomised controlled trials, observational studies, case series and case reports. Data variability was assessed using Stata software.

Main findings

A total of 111 studies were included; of which 22 were randomised controlled trials. Due to heterogeneity, findings were synthesised narratively. The most frequently reported adverse effects were metabolic complications, with approximately one-third of individuals developing corticosteroid-induced lipodystrophy. Infections were the second most common adverse effect (15.5%), followed by gastritis (12.6%). Infections accounted for three-quarters of corticosteroid-associated mortality, predominantly due to tuberculosis, with 88.2% of corticosteroid-associated mortalities occurring in individuals with erythema nodosum leprosum (ENL). There was an association between ENL and the development of cataract and osteoporosis, with 69.7% of cataract cases and 84.4% of osteoporosis cases occurring among individuals with ENL.

Conclusion

This systematic review illustrates the range and severity of adverse effects affecting individuals with leprosy who received systemic corticosteroids. Although this review is limited by study heterogeneity, publication bias, and the scarcity of long-term data, it highlights the need for corticosteroid stewardship, structured pharmacovigilance and further research for safer therapeutic alternatives to corticosteroids for leprosy reactions.

Serotonin signaling modulates growth and motility in juvenile Fasciola hepatica

2026-03-26T14:00:00Z

by Emily Robb, Sarah Muise, Lana Watt, Rebecca Armstrong, Duncan Wells, Paul McCusker, John Harrington, Andreas Krasky, Paul M. Selzer, Nikki J. Marks, Aaron G. Maule

Fasciola hepatica causes fasciolosis, a parasitic disease that poses significant animal and human health challenges. Control relies on flukicides, most of which are adulticides, with only triclabendazole effective against the pathogenic migratory juvenile. Classical neurotransmitter pathways are widely targeted by anthelmintics yet remain underexplored for flukicide development. Here we explore the importance of serotonin (5-HT) signaling in juvenile fluke. In silico analyses confirmed all F. hepatica life stages express a complete 5-HT signaling pathway encompassing genes encoding proteins for 5-HT synthesis, transport, and reuptake, as well as five putative 5-HT G protein-coupled receptors (GPCRs). Homology and binding motif analyses supported the presence of two 5-HT₁ (Fh5HT_1A, Fh5HT_1B) and three 5-HT₇ (Fh5HT_7A, _-7B, _-7C) GPCRs. Immunocytochemistry and in situ hybridization revealed widespread neuronal expression of 5-HT, its synthetic enzyme tryptophan hydroxylase (FhTPH), and the GPCR Fh5HT_7C. 5-HT addition stimulated juvenile fluke motility; consistent with this observation, serotonin reuptake inhibition, which causes 5-HT persistence at synaptic junctions, also enhanced juvenile movement. Silencing of FhTPH, a key enzyme in 5-HT synthesis, blunted juvenile motility, a phenotype reversed by the addition of 5-HT. Silencing the fluke vesicular monoamine transporter (FhVMAT), which packages 5-HT into synaptic vesicles, reduced juvenile motility, whilst silencing the 5-HT reuptake transporter (FhSERT) which recycles synaptic 5-HT increased juvenile motility and growth, consistent with 5-HT accumulation enhancing effects. Whilst combinatorial silencing of Fh5HT₁ receptors reduced fluke motility, silencing Fh5HT₇ receptors led to a greater reduction in motility. Exogenous addition of 5-HT partially rescued motility deficits of juveniles with silenced Fh5HT₁ receptors, but 5-HT excitation was abolished in Fh5HT₇-RNAi juveniles, exposing their importance to fluke motility. Notably, sustained 5-HT exposure promoted juvenile growth, but these effects were not blunted by receptor-RNAi. The findings emphasize a central role of serotonin signaling in both juvenile motility and growth, exposing novel aspects of receptor function and encouraging therapeutic exploitation for liver fluke control.

A novel method for establishing a mouse model of hepatic echinococcosis: Ultrasound-guided percutaneous liver puncture modeling

2026-03-25T14:00:00Z

by Jingyu Wang, Jian Dong, Huijiao Jiang, Huan Zhao, Shengwen Lv, Zhen Wang, Xinhui Cao, Chenghao Liu, Xueling Chen, Xiangwei Wu

Introduction

Research on hepatic echinococcosis relies on stable, reproducible animal models. Traditional open-laparotomy modeling presents issues such as significant trauma and poor consistency.

Objective

To compare the efficacy and safety of ultrasound-guided percutaneous liver puncture inoculation versus traditional open-laparotomy in establishing a hepatic echinococcosis model in C57BL/6 mice.

Methods

Alveolar echinococcus (AE) cystic larvae or cystic echinococcus (CE) scolices were implanted into mouse livers using ultrasound-guided percutaneous liver puncture inoculation and traditional open surgery, respectively. Postoperative dynamic ultrasound monitoring, histopathology, and immunofluorescence staining were employed for systematic evaluation.

Results

The survival rate in the ultrasound-guided group reached 100% (30/30), significantly higher than the 80% (24/30) in the surgical group, representing a difference of 20 percentage points (95% CI: 5.7% to 34.3%; p = 0.039). The complication rate was only 6.7% (2/30) in the ultrasound-guided group, compared to 20% (6/30) in the surgical group, with a difference of -13.3 percentage points (95% CI: -30.2% to 3.6%; p = 0.133). Ultrasound-guided modeling achieved a 100% success rate, with more uniform lesion growth and accelerated progression. Histopathology revealed more typical fibrosis and immune microenvironment characteristics.

Conclusion

Ultrasound-guided percutaneous liver biopsy offers advantages including short procedure duration, minimal trauma, and high model consistency. It significantly enhances modeling efficiency while reducing surgical interference, providing a more reliable animal model platform for hepatic echinococcosis research.

Comparative studies of the effects of Naja ashei venom-derived proteins on model and native lipid membranes

2026-03-25T14:00:00Z

by Barbara Dyba, Barbara Kreczmer, Elżbieta Rudolphi-Szydło, Anna Barbasz, Vladimír Petrilla, Monika Petrillova, Jaroslav Legáth, Aleksandra Bocian, Konrad Kamil Hus

Venoms contain toxins that are increasingly recognized as valuable sources of biologically active compounds. In this study, we examined the biochemical and biophysical properties of PLA_₂, CRISP, and SVMP fractions isolated from Naja ashei venom with the detailed description of their interactions with cell membranes. By integrating these results with our previous analysis of the 3FTx fractions, we provide a broad and coherent overview of the most relevant protein components in N. ashei venom. Experiments were performed on two cancer cell lines with distinct membrane architectures: HL-60 (leukemia) and SK-N-SH (neuroblastoma). These lines differ particularly in membrane cholesterol content and in the saturation level of hydrophobic lipid parts. Our results enabled a comparative assessment of how each protein fraction modulates the mechanical and electrostatic properties of both model and native membranes. In agreement with predictions derived from model lipid systems, leukemia cell membranes were more susceptible to toxin-induced damage than neuroblastoma membranes, likely owing to their higher proportion of unsaturated lipids. Physicochemical analyses confirmed that the isolated PLA₂, CRISP, and SVMP fractions alter key membrane parameters, including stiffness, elasticity, lipid-protein interactions, and the net charge of the polar headgroup region. Importantly, this work provides new insights into the membrane-level effects of SVMP and CRISP proteins, which have been less comprehensively studied compared with well characterized 3FTx and PLA_₂ families. These results reveal distinct, cell membrane–dependent responses to N. ashei venom proteins and justify further basic research to better understand their action with cells.

Vaccination of mice with Trichinella spiralis serine proteinase enhanced gut epithelial barrier and elicited a high protective immunity

2026-03-24T14:00:00Z

by Jin Yi Wu, Xin Zhuo Zhang, Ru Zhang, Yao Zhang, Ruo Dan Liu, Xi Zhang, Shao Rong Long, Zhong Quan Wang, Jing Cui

Background

A Trichinella spiralis serine proteinase (TsSPc) was identified in the intestinal infective larva (IIL) surface and excretory-secretory (ES) antigens. Our previous study showed that recombinant TsSPc (rTsSPc) disrupted intestinal epithelial integrity and barrier function, and mediated larval invasion of intestinal mucosa. This study aims to investigate the impact of rTsSPc vaccination on intestinal epithelial integrity and its elicited protective immunity in a mouse model.

Methodology/principal finding

ELISA results demonstrated that rTsSPc immunization induced a systemic humoral immune response with serum-specific IgG antibody titer reaching 1:10⁵, and elicited a mixed Th1/Th2 immune response dominated by the Th2 type. In the rTsSPc-immunized mice, the TsSPc-specific intestinal sIgA level was also markedly increased (P < 0.0001); The secretion levels of IFN-γ and IL-4 in spleen, mesenteric lymph node (MLN) and Peyer’s patch (PP) cells were significantly increased (P < 0.0001). rTsSPc immunization blocked the binding of parasite-derived TsSPc and gut epithelial RACK 1 receptor, prevented the activation of MAPK/ERK1/2 pathway and enhanced gut epithelial integrity, and impeded the parasite invasion. Vaccination of mice with rTsSPc exhibited a 65.7% reduction of enteral adult burden with a 61.13% decline of female fecundity, and a 58.10% reduction of muscle larval burden. Intestinal inflammation of rTsSPc-immunized mice was also significantly alleviated, as demonstrated that goblet cell numbers were obviously decreased, expression level of mucins (Muc2 and Muc5ac) and pro-inflammatory cytokines (IL-6 and TNF-α) was evidently declined, while expression level of anti-inflammatory cytokines (IL-10 and TGF-β) was distinctly increased after infection. Moreover, peritoneal macrophages of rTsSPc-immunized mice exhibited a mixed M1/M2 polarization, but shifted to a predominant M2 polarization pattern post infection. ADCC assay confirmed that peritoneal macrophage of immunized mice had a stronger anti-rTsSPc antibodies-mediated cytotoxicity killing newborn larvae (P < 0.0001).

Conclusions

rTsSPc vaccination produced a high protective immunity through multiple synergistic mechanisms: eliciting an obvious humoral and cellular immunity, gut local mucosal sIgA responses; blocking the binding of parasite-derived TsSPc to gut RACK1 receptors and the activation of MAPK/ERK1/2 pathway, improved gut epithelial integrity, inhibiting larval invasion, enhancing macrophages’ ability of ADCC killing larvae, and finally reduced parasite burden and alleviated inflammation of intestines and skeletal muscles. TsSPc might be a promising novel candidate target for anti-T. spiralis vaccine.

Detection of Echinococcus multilocularis in coyotes in Washington State, USA highlights need for increased wildlife surveillance

2026-03-24T14:00:00Z

by Yasmine Hentati, Ellie Reese, Claire C. Curran, Erika M. Miller, Dakeishla M. Díaz-Morales, Samantha E.S. Kreling, Guilherme G. Verocai, Laura R. Prugh, Christopher J. Schell, Chelsea L. Wood

Echinococcus multilocularis is a zoonotic cestode that uses canids as definitive hosts and rodents as intermediate hosts. In humans, this parasite is the causative agent of alveolar echinococcosis. Recently, its range has been expanding across the Northern Hemisphere, and it is increasingly detected in wild canids, domestic dogs, and humans across Canada and the United States. While this expansion has been documented in isolated studies across the continent, a lack of routine sampling in wildlife hinders our ability to anticipate and mitigate further spread of E. multilocularis. We confirmed the presence of E. multilocularis in Washington State, USA, using a combination of morphological and molecular techniques across carcasses and field-collected scats of coyotes (Canis latrans), this region’s most common wild canid. Morphological identification of adult worms was confirmed by next-generation sequencing. Over a third of all samples tested positive for E. multilocularis when all methodologies were combined. Sequencing revealed a haplotype of E. multilocularis matching a documented haplotype originally of European origin in British Columbia, Canada. Our study provides the first confirmation of E. multilocularis in a wild host on the west coast of the contiguous United States and provides additional haplotype information crucial to tracking the geographical expansion of the parasite. We also provide a new next-generation sequencing primer targeting cestodes of canids. The difference in amplification between intestinal and fecal samples suggests that non-invasive fecal sampling using DNA metabarcoding - a popular method of helminth surveillance - may lead to underestimation of prevalence, hindering control measures. The global significance of these findings extends beyond North America; E. multilocularis is a major public health concern in Europe and Asia, where alveolar echinococcosis is increasingly diagnosed in humans. Our study highlights the urgent need for increased surveillance and improved diagnostic strategies worldwide, particularly in regions with significant human-wildlife contact.

Rapid identification of Biomphalaria spp. and diagnosis of Schistosoma mansoni infestation using MALDI-TOF mass spectrometry

2026-03-24T14:00:00Z

by Diara Sy, Lionel Almeras, Adama Zan Diarra, Souleymane Doucoure, Yacine Mbere Sarr, Coralie L’Ollivier, Papa Mouhamadou Gaye, El Hadji Ibrahima Ndiaye, Bruno Senghor, Doudou Sow, Cheikh Sokhna, Stephane Ranque

This study explores the use of Matrix-Assisted Laser Desorption/Ionization Time-of-Flight mass spectrometry (MALDI-TOF MS) to identify and differentiate Biomphalaria snails infected with the parasite S. mansoni, which causes schistosomiasis. The study was conducted on two snail species, Biomphalaria pfeifferi (collected in the field in Senegal) and Biomphalaria glabrata (a laboratory strain). The snails were infected in the laboratory with S. mansoni miracidia, and their infection was confirmed by cercariae emission tests and quantitative PCR (qPCR). MALDI-TOF MS was then used to analyse proteins from infected and uninfected snails to identify spectral differences. Based on protein profiles, the results of MALDI-TOF mass spectrometry made it possible to accurately differentiate between S. mansoni-infected snails and uninfected snails. An increase in the number of peaks detected and their intensity was observed for the spectra of S. mansoni-infected snails compared to uninfected snails. The application of principal component analysis (PCA) to these mass spectrometry profiles confirmed the discrimination between the two groups according to their infection status. In addition, specific discriminating peaks were identified for each snail species, allowing for the distinction of infected from uninfected snails. The present study revealed, for the first time, that MALDI-TOF MS appears to be a rapid, reliable, and specific tool for the diagnosis of schistosomiasis in snails, offering promising prospects for the surveillance and control of this disease in endemic areas. However, further work is needed to establish a MALDI-TOF MS reference spectra database specific to Schistosoma parasites and to standardise sample collection, storage, and preparation in order to apply this technique in the field.

The differential roles of Giardia duodenalis-secreted tenascins in inducing intestinal epithelial cell apoptosis and the attributed EGFR-STAT3 axis regulation

2026-03-23T14:00:00Z

by Shui Yu, Zhepeng Sun, Yiqi Wang, Peipei Zhang, Hongxing Sun, Ziqi Meng, Chufan Yang, Yu Shen, Zhanhao Guo, Wei Li

Giardia duodenalis is an important extracellular protozoan parasite of the gut responsible for waterborne diarrhea in human and nonhuman animals worldwide. Giardia trophozoites express and secrete excretory-secretory proteins (ESPs) affecting structural, cellular, and soluble components of the host small intestinal milieu, of which tenascins are present in high abundance. Giardia-induced intestinal epithelial cell (IEC) apoptosis is known as an important aspect of pathogenesis of giardiasis, while the underlying molecular mechanisms remain largely unclear. Here we used in vitro models of IECs to explore the regulatory mechanism of Giardia-induced apoptosis. We initially confirmed the occurrence of apoptosis and the activation of epidermal growth factor receptor (EGFR) when IECs were exposed to Giardia trophozoites, and EGFR activation involved Giardia-induced IEC apoptosis. The recombinant Tenascin15, Tenascin30, and Tenascin33 were then studied for their potential to activate EGFR/signal transducer and activator of transcription 3 (STAT3)-dependent IEC apoptosis. All the three recombinant proteins were demonstrated to be effective in triggering IEC apoptosis and EGFR/STAT3 activation. Strikingly, IEC apoptosis induced by rTenascin15 and rTenascin30 were found to be dependent on the activation and nuclear translocation of EGFR and STAT3, while this is not the case for rTenascin33. Collectively, our study identified tenascins as potential virulence factors related to Giardia-induced IEC apoptosis, and demonstrated that EGFR-STAT3 axis played a critical regulatory role in the process, advancing our understanding of the pathogenesis of Giardia infection.

Application of CRISPR/Cas13a system on the rapid detection of Salmonella spp.

2026-03-23T14:00:00Z

by Yongxin Huang, Wenli Liang, Mingyao Huang, Yingying Deng, Zhenyi Huang, Changhan Ai, Weiqing Tan, Lingxiao Jiang

Background

Salmonella spp. infections can manifest in various clinical symptoms, from asymptomatic carriage to gastroenteritis, and even severe sepsis. Given the rapid progression of the disease and its potential to cause severe outcomes or trigger cluster outbreaks, making the detection of Salmonella spp. critically important. Although broth enrichment culture is considered the gold standard, it is time-consuming and involves multiple steps, making it difficult to meet urgent diagnostic needs. Hence, prompt and precise detection of Salmonella spp. is crucial not only for early diagnosis and effective treatment, but also for preventing transmission, controlling outbreaks, and screening asymptomatic Salmonella carrier.

Methods

This study developed a clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR associated (Cas) -SE assay that integrated the advantages of the recombinase polymerase amplification (RPA) and CRISPR/Cas13a system for detecting Salmonella spp. The clinical performance of CRISPR/Cas13a-SE assay was evaluated by a cohort of 94 inpatients with diarrhea and three prospective studies.

Results

The CRISPR/Cas13a-SE assay can be completed within 60 minutes, and its limit of detection was 100 fg/μL. Compared to the broth enrichment culture, the CRISPR/Cas13a-SE assay demonstrated a sensitivity of 87.5% and a specificity of 98.8% in a cohort of 94 inpatients with diarrhea. In our prospective studies involved three distinct cohorts: 1,662 food handlers, 211 outpatients with diarrhea, and 154 inpatients with Gram-negative bacteremia. Compared with broth enrichment culture, CRISPR/Cas13a-SE assay had a high concordance rate of 98.79% (1,642/1,662), 99.52% (210/211), and 100.00% (154/154) respectively.

Conclusions

We demonstrated that the CRISPR/Cas13a-SE system showed excellent detection performance for infectious diarrhea caused by Salmonella spp. The combined use of CRISPR/Cas13a-SE with the blood culture method enhances the rapid diagnosis of invasive salmonellosis, which is crucial for early target-based therapy. Additionally, screening of asymptomatic Salmonella carrier will be benefit for disease prevention and control.

Descriptions of the natural history of erythema nodosum leprosum to inform clinical classification – A semi-systematic review

2026-03-23T14:00:00Z

by Barbara de Barros, Saba Lambert, Vivianne Lopes Antonio Dias, Diana N.J. Lockwood, Stephen L. Walker

Background

Erythema nodosum leprosum (ENL) is a severe immunological complication of leprosy, characterised by painful nodules, fever, arthralgia, oedema, and systemic symptoms. Temporal classifications—acute, recurrent, and chronic—are inconsistently applied, complicating data comparisons. Standardised and agreed definitions are essential to ensure consistency in diagnosis, research, and clinical management.

Objective

To examine how temporal classifications of ENL are used in modern literature and compare them to descriptions from the pre-corticosteroid era.

Methods

We conducted a semi-systematic review of historical and contemporary literature. Historical texts published before 1940, prior to the introduction of sulfone antibiotics and corticosteroids, were purposively selected to capture descriptions of the natural history of ENL. For modern studies, we systematically searched PubMed, EMBASE, LILACS, SciELO, Scopus, African Index Medicus, Cochrane, and ClinicalTrials.gov from May 2024 to March 2025. The systematic review identified 572 articles after de-duplication, and 41 met inclusion criteria for providing definitions of ENL subtypes.

Results

Five historical treatises were selected. Their clinical observations of nodular skin lesions with systemic symptoms—ranging in duration from weeks to months or even years—align with contemporary understandings of ENL. 41 studies included, at least one of the three temporal classifications (acute, recurrent, or chronic). The six-month criterion distinguishing acute and chronic ENL is used in all current definitions. However, definitions for recurrent and chronic ENL frequently overlapped, both referring to prolonged or multiple episodes after initial treatment, underscoring a lack of conceptual clarity.

Conclusion

The absence of standardised ENL terminology impedes data comparison, meta-analysis, and clinical guideline development. A Delphi consensus process and longitudinal observational studies are recommended to refine, standardise agreed ENL classifications.

Burden of cystic and alveolar echinococcosis in the Kyrgyz Republic

2026-03-23T14:00:00Z

by Gulnara Minbaeva, Nelya Akhunbaeva, Kalis Nogoibaeva, Vera Toygombaeva, Kenesh Dzhusupov, Paul R. Torgerson

The purpose of this study is to assess some aspects of the burden of cystic and alveolar echinococcosis in the Kyrgyz Republic. From 2015-2020 a total of 5568 cases of primary cystic echinococcosis (CE) were reported and a further 1008 recurrent cases. Over the same time period 880 primary cases of primary alveolar echinococcosis (AE) were reported and a further 343 recurrent cases. The estimated DALYs for CE was 7849, that is 1308 per annum or 19.5 per 100,000 per annum. For AE was there were 3809 DALYs, that is 634 per annum or 9.5 per 100,000 per annum. The proportion of fatal cases of AE was 3.6 times higher than from CE. The total economic damage in terms of purchasing power equivalent (PPE) from CE amounted to more than 10,5 million international US dollars. For AE it amounted to more than 5.1 million international US dollars. Most of the financial burden falls on the patients themselves and amounts to 68.4%, i.e., 1223 PPE dollars per case out of total spending 1615 PPE dollars per case. To reduce the social and economic burden of echinococcosis, it is necessary to timely identify the disease, prevent the development of complications and multiple lesions, and promote preventive chemotherapy where appropriate. A deep understanding of the etiology, epidemiology, clinical manifestations, and tactics of early diagnosis of various forms of echinococcosis is also important for timely detection, effective control, and, most importantly, the organization of preventive measures to combat this disease.