International journal for parasitology最新文献

{"title":"Climatic suitability and phylogeography reveal cryptic diversity and public health risk in the Amblyomma testudinarium complex and other Asian Amblyomma.","authors":"Ernest J M Teo, Samuel Kelava, Mackenzie Kwak, Gita Sadaula Pandey, Ryo Nakao","doi":"10.1016/j.ijpara.2026.104902","DOIUrl":"10.1016/j.ijpara.2026.104902","url":null,"abstract":"<p><p>Amblyomma testudinarium sensu lato, a vector of medically important pathogens, including severe fever with thrombocytopenia syndrome virus, represents a species complex known from East Asia, South Asia, and Southeast Asia. Genetic and distributional data pertaining to these ticks are scattered, challenging One Health strategies. Using genetic information and distributional records of A. testudinarium s.l. and related species, we found two clades of A. testudinarium. We also found that Amblyomma javanense and Amblyomma varanense likely represent species complexes. We project the geographic ranges of the two A. testudinarium clades, highlighting variation in disease risk and gaps in knowledge that need to be answered for the betterment of public health.</p>","PeriodicalId":13725,"journal":{"name":"International journal for parasitology","volume":" ","pages":"104902"},"PeriodicalIF":3.3,"publicationDate":"2026-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148224758","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A novel hookworm vaccine candidate identified through immunomic profiling of human protective immunity.","authors":"Eti Sarkar, Connor McHugh, Michael Smout, Tamara Thomas, Li Liang, Rie Nakajima, Emily Silzel, Philip Felgner, Yide Wong, Paul Giacomin, James McCarthy, Paul Chapman, Suchandan Sikder, Alex Loukas","doi":"10.1016/j.ijpara.2026.104901","DOIUrl":"10.1016/j.ijpara.2026.104901","url":null,"abstract":"<p><p>Hookworms infect nearly half a billion people, causing approximately 2.1 million disability-adjusted life-years lost. While anthelmintic drugs are available, they do not prevent reinfection. A vaccine could provide long-term immunity, but none currently exists. We recently demonstrated that human subjects could be safely vaccinated with irradiated hookworm larvae, eliciting humoral and cellular immune responses that induce partial protection against challenge infection with non-irradiated parasites. Using immunomic approaches, we identified IgG targets in vaccinated individuals by screening a proteome microarray containing recombinant proteins sourced from the secretome of Necator americanus. We characterized the most immunoreactive N. americanus proteins and identified their orthologs in the rodent hookworm Nippostrongylus brasiliensis. These N. brasiliensis proteins were expressed recombinantly and tested for efficacy in a mouse challenge model. Our lead vaccine candidate NBR17057 - a homolog of Na_11335 provided robust protection against infection, evidenced by >90% reductions in intestinal worm burden and fecal egg counts, and elevated antigen-specific IgG levels. Vaccination also stimulated IgA⁺ B-cells, IgG1⁺/IgA⁺ plasma cells, and IgG1⁺/IgA⁺ germinal centre B-cells in inguinal lymph nodes, indicating gut immunity. Additionally, high levels of IgG1⁺/IgA⁺ B-cells, germinal centre B-cells, and plasma cells in the spleen suggest protection against systemic larval migration. The presence of IgG1⁺/IgA⁺ memory B-cells in both the lymph nodes and spleen indicates potential long-term immunity against reinfection. Our findings suggest that a N. brasiliensis L3 larval-stage protein NBR17057 and its homolog in N. americanus Na_11335 could serve as a promising subunit vaccine candidate targeting the infective larval stage of human hookworms.</p>","PeriodicalId":13725,"journal":{"name":"International journal for parasitology","volume":" ","pages":"104901"},"PeriodicalIF":3.3,"publicationDate":"2026-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148211183","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Co-occurrence patterns of internal parasitic nematodes and coccidia in wild bighorn sheep depend on host geography and environment.","authors":"Marci F Witczak, Robert S Spaan, Claire E Couch, Eilea R Delgadillo, Clinton W Epps, Justin L Sanders, Johannie M Spaan, Scott Torland, Donald Whittaker, Anna E Jolles, Brianna R Beechler","doi":"10.1016/j.ijpara.2026.104900","DOIUrl":"10.1016/j.ijpara.2026.104900","url":null,"abstract":"<p><p>Heterogeneity of internal parasite communities amongst host animals is shaped by processes at multiple scales, including landscape distribution of parasites, individual host suitability, and parasite interactions within a host. As a result, pathogen co-occurrence patterns vary across space and time and among host populations. Often the challenges of wildlife sampling limit understanding of the drivers of pathogen community heterogeneity in host animals. In this study, we explore patterns and drivers of parasite community heterogeneity amongst wild bighorn sheep (Ovis canadensis) hosts over time and across populations. We describe temporal patterns including (i) general seasonal patterns of nematode and coccidia infection and (ii) taxon-specific patterns that differ by parasite life histories for bighorn sheep in southeastern Oregon and northern Nevada over a five-month period. Additionally, we describe patterns of parasite associations, many of which appear to result from co-occurrence on the landscape and others that may arise from interactions among parasites within a host. At a lower taxonomic resolution, coccidia and nematodes were positively associated with Normalized Difference Vegetation Index (NDVI), a measure of landscape vegetation greenness; at a higher taxonomic resolution, Protostrongylus was the only nematode positively associated with NDVI. Eimeria was positively associated with Ostertagia and negatively associated with Marshallagia, both abomasal nematodes. These two associations were independent of host geographical distribution and landscape vegetation greenness, suggesting that these co-occurrences may be a result of parasite interactions. This study establishes a recent and geographically expansive exploration of internal nematodes and coccidia present in a wildlife system comprising multiple populations and demonstrate the need for future investigation into parasite interactions.</p>","PeriodicalId":13725,"journal":{"name":"International journal for parasitology","volume":" ","pages":"104900"},"PeriodicalIF":3.3,"publicationDate":"2026-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148175769","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative diagnostic evaluation of microscopy and targeted next-generation sequencing of the barcoding gene cytochrome oxidase subunit I for tick identification in British Columbia, 2021-2023.","authors":"Adriana Cabrera, Tracy D Lee, Angel Y Yao, John Tyson, Kathleen Kolehmainen, Isaac Singh, Martin Cheung, Min-Kuang Lee, LingHui David Su, Navdeep Chahil, Frankie Tsang, Stefan Iwasawa, Quinn Stewart, Erin Fraser, Louwrens P Snyman, Natalie Prystajecky, Jade Savage, Muhammad G Morshed, Catherine A Hogan","doi":"10.1016/j.ijpara.2026.104897","DOIUrl":"10.1016/j.ijpara.2026.104897","url":null,"abstract":"<p><p>Tick surveillance protocols in public health laboratories have traditionally relied on microscopy for species identification. However, recognition of emerging species with overlapping morphology, loss of expertise, and new technologies have highlighted the need for complementary testing approaches. We performed a comparative diagnostic evaluation assessing accuracy of next-generation sequencing targeting the barcoding portion of cytochrome oxidase subunit I (COI) against traditional microscopy for tick identification. A total of 306 Dermacentor and Ixodes ticks were included in the study. Overall agreement between the methods was >90%. Molecular testing highlighted the challenges with identifying ticks to the species level by morphology alone, especially for rare and/or emerging species. Molecular testing proved useful as a quality assurance tool for microscopy and highlighted the need for targeted continuing education to strengthen morphological analysis expertise. Finally, the COI NGS workflow demonstrated feasibility for integration into routine laboratory sequencing workflows. Our findings support the utility of COI sequencing as a complementary diagnostic approach in reference laboratories where tick identification and surveillance are performed.</p>","PeriodicalId":13725,"journal":{"name":"International journal for parasitology","volume":" ","pages":"104897"},"PeriodicalIF":3.3,"publicationDate":"2026-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148163163","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparing performance of copro-diagnostics for monitoring intestinal parasitic infections in the golden jackal (Canis aureus).","authors":"Elisabetta Ferraro, Paola Beraldo, Erica Marchiori, Giulia Simonato, Francesca Vianello, Sabrina Iraci, Mauro Giammarino, Alessandro Massolo, Rudi Cassini","doi":"10.1016/j.ijpara.2026.104899","DOIUrl":"10.1016/j.ijpara.2026.104899","url":null,"abstract":"<p><p>The golden jackal Canis aureus is regarded as a potential bridge host for emerging parasites in Europe to domestic animals, owing to its adaptability to live in human-dominated landscapes. As the species continues to expand in Europe, copromicroscopy offers a non-invasive alternative to necropsy-based methods to obtain epidemiology data, but its performance on jackals has never been assessed. We compared the performance of two copromicroscopic tests, flotation technique (FT) and Mini-FLOTAC (MF), to the Scraping, Filtration and Counting technique (SFCT), current standard for helminth detection, and assessed their agreement. The intestinal contents and corresponding fecal samples from 84 golden jackals were examined. Sensitivity and specificity of FT and MF relative to SFCT were estimated for each detected taxon (Toxocara canis, Trichuris vulpis, strongylids, Mesocestoides spp., and Taenia spp.). Associations between adult parasite burden and copromicroscopic positivity were explored using non-parametric tests and logistic regression models. Agreement between FT and MF was assessed using concordance and Gwet's γ(AC1). Both FT and MF detected the most prevalent helminth species at SFCT, but showed low sensitivity, ranging from 28.6% to 56.5%. Parasite intensity did not significantly influence copromicroscopic positivity for most taxa, and quantitative MF results did not linearly reflect parasite loads. The two methods showed comparable performance, suggesting that their use may be guided by operational constraints and study objectives. Despite their limitations, copromicroscopic techniques represent useful tools for epidemiological surveillance in jackal populations, provided that adequate sample sizes are used and prevalence estimates are adjusted for test sensitivity and specificity.</p>","PeriodicalId":13725,"journal":{"name":"International journal for parasitology","volume":" ","pages":"104899"},"PeriodicalIF":3.2,"publicationDate":"2026-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148163202","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Molecular and parasitological evidence of Leishmania (Mundinia) martiniquensis infection in a horse from Brazil.","authors":"João Augusto Franco Leonel, Mariana Dantas da Silva, Andreina de Carvalho Araujo, Geovanna Vioti, João Pedro Borges Martins, Ricardo de Francisco Strefezzi, Fredy Galvis-Ovallos, Eunice Aparecida Bianchi Galati, Trícia Maria Ferreira de Sousa Oliveira","doi":"10.1016/j.ijpara.2026.104898","DOIUrl":"10.1016/j.ijpara.2026.104898","url":null,"abstract":"<p><p>Leishmania (Mundinia) martiniquensis is an emerging human pathogen with increasing reports of infection in domestic animals. This study describes a naturally infected mare from Brazil with no history of international travel, presenting with persistent nodular cutaneous lesions and cervical lymph node enlargement, without evidence of systemic involvement. Considering the endemicity of cutaneous and visceral leishmaniasis in the study area, as well as previous reports of equine leishmaniasis, infection by Leishmania (Leishmania) infantum was initially suspected. Anti-L. (L.) infantum antibodies (titer 320) were detected by indirect immunofluorescence assay, and histopathological analysis of the lymph node revealed amastigote forms compatible with Leishmania spp. Therefore, while the etiological agent was still unknown, xenodiagnosis using Lutzomyia (Lutzomyia) longipalpis was performed during the diagnostic investigation based on the initial suspicion of L. (L.) infantum infection. Limited blood feeding was observed, and no evidence of parasite transmission was detected. In addition, flagellated parasites were isolated in vitro from a fine-needle aspiration biopsy of the cervical lymph node. Molecular characterization of clinical samples and culture isolate was performed by amplification of Leishmania spp. kinetoplast DNA (kDNA) and the internal transcribed spacer 1 (ITS1) region of Trypanosomatidae ribosomal DNA, followed by Sanger sequencing, which revealed the presence of L. (M.) martiniquensis. These findings provide documented evidence of natural infection by L. (M.) martiniquensis in a horse in Brazil and highlight the circulation of this emerging pathogen in areas endemic for cutaneous and visceral leishmaniasis. Furthermore, they reinforce the need for additional studies to better elucidate its epidemiological cycle and vector-host interactions.</p>","PeriodicalId":13725,"journal":{"name":"International journal for parasitology","volume":" ","pages":"104898"},"PeriodicalIF":3.2,"publicationDate":"2026-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148163154","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Systematics and phylogeny of Chalcinotrematinae (Digenea: Haploporidae): Erection of a new genus and description of two new species from South America through integrated analyses","authors":"Camila Pantoja ,&nbsp;Olena Kudlai ,&nbsp;Maarten P.M. Vanhove ,&nbsp;Rodney A. Bray ,&nbsp;José L. Luque ,&nbsp;Nikol Kmentová ,&nbsp;Tomáš Scholz","doi":"10.1016/j.ijpara.2025.11.005","DOIUrl":"10.1016/j.ijpara.2025.11.005","url":null,"abstract":"<div><div>The subfamily Chalcinotrematinae (Haploporidae) comprises an understudied group of digenean parasites infecting freshwater and brackish water fishes across the Americas, Africa, and Asia. Its systematics has rarely been investigated using molecular data, with DNA sequences available for only a few species representing two of the six recognised genera. We collected chalcinotrematine trematodes from freshwater fishes in the Jari River, Amazon Basin, Brazil, and in Misiones, Argentina. Specimens from Brazil were characterised through an integrative approach combining morphological examination with molecular data (partial 28S and ITS2 rDNA sequences), whereas those from Argentina were analysed morphologically. As a result, we describe two new species from Brazil: <em>Chalcinotrema arleneae</em> sp. nov. from <em>Leporinus friderici</em> and <em>Laemolyta proxima</em>, and <em>Unicoelium gerardoi</em> sp. nov. from <em>Hypostomus plecostomus</em>. This study provides the first molecular data for both <em>Chalcinotrema</em> and <em>Unicoelium</em>, expanding the phylogenetic framework of Chalcinotrematinae. <em>Paralecithobotrys brasiliensis</em> is recorded from Argentina in <em>Megaleporinus obtusidens</em>, extending its geographical range. We reassessed the generic limits of <em>Saccocoelioides</em>, the most species-rich genus within the subfamily. Based on combined morphological, molecular, host, and distributional evidence, we propose taxonomic revisions, establishing <em>Neosaccocoelioides</em> gen. nov. for several South American species formerly assigned to <em>Saccocoelioides</em>: <em>N. antonioi</em> comb. nov., <em>N. bacilliformis</em> comb. nov., <em>N. elongatus</em> comb. nov., <em>N. magnus</em> comb. nov., <em>N. miguelmontesi</em> comb. nov. (type species), and <em>N. szidati</em> comb. nov. Additionally, <em>N. platense</em> comb. nov., previously placed in <em>Chalcinotrema</em>, is transferred to the new genus. <em>Saccocoelioides chilkaensis</em> and <em>S. lizae</em> are considered <em>species inquirendae</em>; and <em>S. guaporense</em> is considered <em>incertae sedis.</em> These findings refine chalcinotrematine relationships and highlight the need for expanded molecular datasets to resolve systematic and biogeographical uncertainties.</div></div>","PeriodicalId":13725,"journal":{"name":"International journal for parasitology","volume":"56 6","pages":"Article 104753"},"PeriodicalIF":3.2,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145633127","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Adjuvant-driven modulation of epitope recognition and protective immunity in Bm86 vaccinated Holstein-Friesian cattle","authors":"Laura Jane Bishop ,&nbsp;Christian Stutzer ,&nbsp;Jannie Crafford ,&nbsp;Christine Maritz-Olivier","doi":"10.1016/j.ijpara.2025.11.006","DOIUrl":"10.1016/j.ijpara.2025.11.006","url":null,"abstract":"<div><div>Livestock production is vital to the economies and food security of African countries. Rising global demand for livestock-derived products intensifies the challenge of managing ticks and tick-borne diseases. This study aimed to optimize a Bm86-based vaccine for controlling <em>Rhipicephalus microplus</em>. Commercial Bm86-based vaccines show variable efficacy (0–100 %), reflecting incomplete understanding of the antigen and the immune response elicited. To address this, homologous challenge was conducted in Holstein-Friesian calves with Bm86 formulated with Montanide™ ISA 71 VG (referred to as Montanide™) and a novel Alum-based adjuvant alternative in two separate vaccine trials. Antibody responses were determined utilising indirect ELISA. Vaccine efficacy was assessed through controlled <em>R. microplus</em> challenge. Immunoinformatics mapped the antigenic regions of Bm86, followed by <em>ex vivo</em> validation using antisera from vaccinated cattle. Both adjuvant formulations induced high levels of Bm86-specific total IgG antibodies. However, only the Montanide™ formulation induced a protective response of 88.2 %, which correlated with total IgG antibody levels (<em>r</em> = 0.86). In contrast, the Alum-based adjuvant formulation induced low efficacy (2.3 %) with a strong inverse correlation with total IgG antibodies (<em>r</em> = −0.95). Both formulations induced an IgG1-biased (i.e. T-helper 2) antibody response, but the Montanide™ formulation conferred a more balanced IgG1/IgG2 response. The efficacy induced by the Montanide™ formulation strongly correlated with the levels of IgG2 antibodies (<em>r</em> = 0.91), suggesting that a balanced Th1/Th2 response plays a key role in protection. Despite its efficacy, the Montanide™ formulation caused adverse injection site effects, highlighting the need for safer alternatives. Epitope mapping identified similar linear B-cell epitope regions recognised by total IgG antibodies induced by vaccination with both adjuvant formulations. These findings suggest that Bm86 vaccination activates broader immune pathways than previously understood, emphasizing the need for exploration of additional immune markers to improve vaccine performance.</div></div>","PeriodicalId":13725,"journal":{"name":"International journal for parasitology","volume":"56 6","pages":"Article 104754"},"PeriodicalIF":3.2,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145668159","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Beneath the surface: gut microbes, cyathostomins and resident immune cells – Characterising the baseline","authors":"Zeynep Yerlikaya ,&nbsp;Raúl Miranda-CasoLuengo ,&nbsp;Hanne Jahns ,&nbsp;Orla Byrne ,&nbsp;Wim G. Meijer ,&nbsp;Grace Mulcahy ,&nbsp;Nikki Walshe","doi":"10.1016/j.ijpara.2025.11.007","DOIUrl":"10.1016/j.ijpara.2025.11.007","url":null,"abstract":"<div><div>Cyathostomins are the most prevalent and currently considered the most pathogenic gastrointestinal nematodes in horses. Their life cycle includes an encystment phase within the large intestinal mucosa, where up to 90 % of the total worm burden resides. Clinical disease ranges from chronic protein-losing enteropathy to acute, sometimes fatal, typhlocolitis. Despite their significance, the ecological interplay between cyathostomins, the host immune response, and the gut microbiota remains poorly understood. To our knowledge, this is the first study to investigate these interactions at the mucosal level. Eleven horses were randomly selected from an abattoir survey. Samples were collected from the caecum, right ventral colon, and left dorsal colon. Parasitological assessments included faecal egg counts, luminal worm enumeration, and mucosal larval counts. Immunological analysis comprised histopathology and immunohistochemistry, while microbiota profiling was performed using bioinformatics. All horses were infected with cyathostomins, including those with zero faecal egg counts. Mucosal larval burdens were highest in the caecum and right ventral colon, while luminal adult worms predominated in the ventral and dorsal colon. T lymphocytes and macrophages were the dominant immune cells in the mucosa; eosinophils and goblet cell hyperplasia showed no correlation with parasite load. Larval invasion of the submucosa was observed only in horses with high mucosal burdens, suggesting density-dependent tissue penetration. Microbiota analysis revealed increasing divergence along the intestinal tract, with caecal and faecal samples showing the greatest differences. These findings highlight regional specialization and suggest that faecal samples may not accurately reflect mucosal microbiota composition. This descriptive study provides novel insights into the spatial dynamics of cyathostomin infection, mucosal immunity, and microbiota composition in the equine large intestine, offering a foundation for future research into equine gastrointestinal health and parasitology.</div></div>","PeriodicalId":13725,"journal":{"name":"International journal for parasitology","volume":"56 6","pages":"Article 104755"},"PeriodicalIF":3.2,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145714306","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Environmental drivers of parasitic nematode infection in wild ungulates in the Serengeti National Park","authors":"Basil C. Senso ,&nbsp;Jason E. Donaldson ,&nbsp;T. Michael Anderson ,&nbsp;Aidan Trentinus ,&nbsp;Vanessa O. Ezenwa ,&nbsp;Ricardo M. Holdo","doi":"10.1016/j.ijpara.2026.104772","DOIUrl":"10.1016/j.ijpara.2026.104772","url":null,"abstract":"<div><div>Parasite infections in host populations frequently display seasonal patterns that can shape host behavior, fitness, and population dynamics. Despite recognition that seasonality plays a key role in infection dynamics across numerous host-parasite systems, the drivers of seasonal infection dynamics for parasites with different life cycles are often unknown. This lack of system-specific understanding restricts our ability to predict when and why parasite infections and their cascading effects on host populations will have the greatest impact. We investigated how seasonality and environmental variables at the likely time of infection are related to the infection intensity of two parasitic nematodes with contrasting life cycles: strongyle nematodes (direct life cycle) and lungworms (indirect life cycle). We conducted the study in two free-ranging ungulate species in Serengeti National Park, Tanzania: Coke’s hartebeest (<em>Alcelaphus buselaphus</em>) and topi (<em>Damaliscus lunatus</em>). We found a high prevalence of both parasites, with strongyle nematodes occurring in 95.5% of hartebeest and 93.1% of topi, and lungworms occurring in 100% of hartebeest and 99.7% of topi. Strongyle infection intensity peaked in the wet season but showed no strong association with precipitation, temperature, or animal density at the likely time of infection. In contrast, lungworm intensity peaked in the dry season and was associated negatively with precipitation and positively with animal occupancy. Our results highlight the importance of considering how parasite life cycles interact with environmental variables operating at different temporal scales, as seasonal infection patterns may emerge from processes acting at distinct times relative to parasite development and transmission. Identifying when parasite intensities are highest is critical for predicting when hosts are under the greatest ecological pressure due to parasitism.</div></div>","PeriodicalId":13725,"journal":{"name":"International journal for parasitology","volume":"56 6","pages":"Article 104772"},"PeriodicalIF":3.2,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146018425","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}