Parasit Vectors [JOURNAL]
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200 papers
Are mosquito species present in Spain competent for Oropouche virus?
Gutiérrez-López R, Labiod N, López-de-Felipe M … +10 more , Sánchez-Mora P, Delacour-Estrella S, Martín-Ramírez A, Potente A, Pérez-Martínez E, Molina R, Sánchez-Seco M, Jiménez M, Vázquez A, Martín-Martín I
Parasit Vectors · 2026 Jun · PMID 42249428 · Full text
BACKGROUND: Oropouche virus (OROV; Orthobunyavirus) is an emerging arbovirus endemic to South America and the Caribbean, with imported cases in European countries, including Spain. Although primarily transmitted by bitin...
BACKGROUND: Oropouche virus (OROV; Orthobunyavirus) is an emerging arbovirus endemic to South America and the Caribbean, with imported cases in European countries, including Spain. Although primarily transmitted by biting midges (Culicoides spp.), OROV has been detected in several mosquito species, raising concerns about potential establishment in nonendemic regions. European populations of Aedes albopictus, and Culex pipiens, as well as the invasive Aedes aegypti, represent relevant models for assessing vector competence. OBJECTIVES: Here, we evaluated the vector competence of Spanish Cx. pipiens biotype molestus, Spanish Ae. albopictus, and Ae. aegypti (Liverpool strain), for the 2024 OROV outbreak strain. Female mosquitoes were orally exposed to infectious blood meals and maintained under controlled insectary conditions at 27 °C. In addition, an additional group received a second noninfectious blood meal. The survival of the mosquitoes was monitored, and infection, dissemination, and transmission rates were assessed at 7, 14, and 21 days post infection. Vertical transmission of the virus to the progenies was also analyzed. RESULTS: Overall, Ae. albopictus exhibited low infection rates, with occasional dissemination and transmission events. Aedes aegypti and Cx. pipiens biotype molestus showed infection and occasional dissemination, but no evidence of transmission. A second noninfectious blood meal did not significantly affect infection, dissemination, or transmission rates in any species. Viral loads in bodies and legs were low and did not differ significantly between species, time points, or feeding regimens. Survival was not affected by infection or blood-feeding regime. We did not find vertical transmission of OROV to the progenies. CONCLUSIONS: Regardless of virus dissemination in mosquitoes, our study indicates a poor vector competence of Spanish Ae. albopictus and no evidence of transmission under the conditions tested in Ae. aegypti and Cx. pipiens biotype molestus for the circulating OROV strain. These findings suggest a low risk for local OROV establishment in Spain, although continuous surveillance and research are warranted to monitor potential vector-virus adaptation.
Specificity of Phlebotomus papatasi and Phlebotomus tobbi recombinant salivary proteins developed as serological surveillance tool.
Přibylová H, Pekagirbas M, Arserim SK … +12 more , Yetismis K, Berberoglu U, Altug U, Elbaz S, Nachum-Biala Y, Kirstein OD, Baneth G, Özbel Y, Töz S, Maia C, Volf P, Kolářová I
Parasit Vectors · 2026 Jun · PMID 42244016 · Full text
BACKGROUND: Sand flies are vectors of various pathogens, primarily Leishmania and phleboviruses. The effectiveness of disease control strategies can be assessed using serological tests that measures antibodies against sa...
BACKGROUND: Sand flies are vectors of various pathogens, primarily Leishmania and phleboviruses. The effectiveness of disease control strategies can be assessed using serological tests that measures antibodies against sand fly saliva as a marker of host exposure and a proxy biomarker of sand fly-borne pathogens transmission. Recently, we proposed novel recombinant salivary proteins to evaluate exposure of dogs to Phlebotomus tobbi and P. papatasi. The aim of this study was to test vector and host specificity of these recombinant proteins. METHODS: Recombinant salivary proteins of P. papatasi (PAP-rSP32, PAP-rSP36, and PAP-rSP42) and P. tobbi (TOB-rSP10, TOB-rSP38, TOB-rSP56, TOB-rSP60) were tested in an enzyme-linked immunosorbent assay (ELISA) using sera from dogs and mice experimentally bitten by a single sand fly species as well as from naturally exposed dogs. RESULTS: Among the three P. papatasi recombinant proteins tested, rSP36 apyrase exhibited the highest vector species-specificity. It did not cross-react with antibodies from dogs or mice experimentally bitten by P. perniciosus, P. tobbi, P. sergenti, Sergentomyia schwetzi, Lutzomyia longipalpis, or two mosquito species (Culex pipiens molestus and C. quinquefasciatus), closely followed by rSP42 yellow-related protein. In contrast, PAP-rSP32 showed host-related species specificity, cross-reacting with murine anti-P. perniciosus antibodies, but not with canine ones. Among the four P. tobbi recombinants, rSP38 yellow-related protein was the only vector subgenus-specific antigen across all the murine sera tested, followed by rSP10 apyrase and rSP60 D7-related protein, which cross-reacted with anti-P. papatasi IgG. The other D7-related protein, rSP56, lacked sand fly-specificity as it cross-reacted with antibodies against Culex saliva. CONCLUSIONS: ELISA assays based on PAP-rSP36, PAP-rSP42, and TOB-rSP38 are recommended for large-scale field studies as they exhibited the highest species-specificity. These assays can provide epidemiologically relevant data that complement other surveillance and leishmaniasis control tools.
Leishmania infantum infection in Phlebotomus perniciosus and Phlebotomus perfiliewi (Diptera, Psychodidae) and their abundance in central Italy.
Del Lesto I, Scarpulla M, De Liberato C … +12 more , Magliano A, Greco S, Salvato L, Marafini G, Ermenegildi A, Carioti V, Chiavacci M, Cartolano C, Cacace R, Porchia BR, Millo A, Romiti F
Parasit Vectors · 2026 Jun · PMID 42243870 · Full text
BACKGROUND: Leishmaniasis caused by the parasitic protozoan Leishmania infantum is endemic in central and southern Italy, but systematic vector surveillance has historically been lacking. Following human cases of viscera...
BACKGROUND: Leishmaniasis caused by the parasitic protozoan Leishmania infantum is endemic in central and southern Italy, but systematic vector surveillance has historically been lacking. Following human cases of visceral leishmaniasis reported in the Lazio and Tuscany regions of Italy, we implemented a surveillance system aimed at describing the occurrence, seasonal dynamics and infection rates of the main vector species in these regions, consequently identifying periods and areas at higher risk of transmission.Affiliations. Kindly check that the affiliations are correctly presented. If incorrect, kindly modify on proofs. Specifically, please check whether the abbreviations in brackets are required for the city name; if not required, please deleteDone. Affiliations have been checked and abbreviations in brackets have been removed. Graphical abstract. A graphical abstract is mandatory for publication in this journal. Please provide a graphical abstract with proofs.Done. METHODS: Sand flies were collected with CDC-CO light traps from April to November 2023 at 75 rural and suburban farms and at three additional sites close to reported human leishmaniasis cases in urban areas. Traps were operated overnight at 1- or 2-week intervals, and the collected sand flies were sorted, counted and identified morphologically. Sites where sand flies were detected were characterised using bioclimatic variables and altitude, and then grouped into climate clusters using k-means clustering. Seasonal activity was analysed by fitting Gaussian generalised linear models with a negative binomial distribution to the abundance data. Pools of female sand flies were tested for L. infantum by real-time PCR, and infection rates were estimated per site and sampling date. RESULTS: A total of approximately 96,333 sand flies were captured in 40 of the 78 collection sites. Of the 13 provinces monitored, nine were positive for sand flies. Two species of sand flies were identified: Phlebotomus perfiliewi (76% of identified specimens) and P. perniciosus (24%), which co-occurred in most provinces. Three distinct climate clusters were defined, mainly separating coastal low-altitude areas from more inland, hilly sectors. Across clusters, adult sand fly activity peaked in early August, with longer activity periods and higher predicted abundances in coastal and low-altitude areas dominated by P. perfiliewi. Leishmania infantum DNA was detected in sand fly pools from eight sites in six provinces, with infected sand flies present from late June to mid-October. The highest infection estimates occurred at high-abundance rural foci dominated by P. perfiliewi and at hilly sites where P. perniciosus was more abundant. CONCLUSIONS: Both P. perniciosus and P. perfiliewi contribute significantly to L. infantum circulation in central Italy. The areas at risk, seasonal vector dynamics and infection rates identified in this study provide essential information for the timing and targeting of veterinary and public health interventions and awareness campaigns.
Molecular characterisation of extracellular vesicles released by Strongyloides stercoralis infective larvae isolated from a clinical sample.
Deiana M, Veschetti L, Reynolds K … +12 more , Hunt VL, Padovani N, Manfredi M, Vezzelli E, Rizzi E, Degani M, Malerba G, Ursini T, Ronzoni N, Piubelli C, Buonfrate D, Tiberti N
Parasit Vectors · 2026 Jun · PMID 42237397 · Full text
BACKGROUND: Extracellular vesicles (EVs) represent a key mechanism of host-pathogen crosstalk. Numerous helminth parasites have already been reported to shed EV-like structures carrying biomolecules, including small RNAs...
BACKGROUND: Extracellular vesicles (EVs) represent a key mechanism of host-pathogen crosstalk. Numerous helminth parasites have already been reported to shed EV-like structures carrying biomolecules, including small RNAs (sRNAs), with functional effects on target cells. However, the ability of Strongyloides stercoralis to release EVs has yet to be demonstrated. METHODS AND RESULTS: Following the isolation of S. stercoralis infective larvae (iL3s) from faecal samples obtained from a patient with strongyloidiasis, we showed that iL3s maintained in vitro for up to 48 h release EV-like structures. Transmission electron microscopy and nanoparticle tracking analysis highlighted vesicular structures enclosed by a bilayer and with a diameter of 120 nm in range. Small RNA sequencing identified multiple EV-associated sRNA types, including miRNAs, only partly overlapping with the previously described somatic miRNome. Comparative analyses revealed that several EV-associated miRNAs were conserved amongst Strongyloides spp., whereas others appeared specific to S. stercoralis. Prediction analyses indicated that miRNAs and other sRNAs may target human genes associated with the regulation of gene expression and immune response, supporting a potential role in host-parasite interaction. CONCLUSIONS: These findings provide the first experimental evidence that S. stercoralis iL3s release EVs carrying regulatory sRNAs and suggest that EV-mediated RNA delivery may represent an additional tool for host-pathogen interaction. More in-depth investigations of these EVs may provide novel insights into the pathophysiology of strongyloidiasis as well as novel targets for clinical applications.
Landscape modeling as a surveillance strategy for Trypanosoma cruzi vectors in Brazil.
de Oliveira F, Testai R, Ferreira MP … +4 more , Galvão C, Rocha DSB, Jansen AM, das Chagas Xavier SC
Parasit Vectors · 2026 Jun · PMID 42237388 · Full text
BACKGROUND: The transmission of Trypanosoma cruzi in nature is closely linked to the ecology of its vectors, the triatomine insects. Although the geographic distribution of these species is relatively well-known, underst...
BACKGROUND: The transmission of Trypanosoma cruzi in nature is closely linked to the ecology of its vectors, the triatomine insects. Although the geographic distribution of these species is relatively well-known, understanding the characteristics that define their ecological niche and how human interventions alter these conditions remains limited. Rapid and intense environmental changes, driven by activities such as agricultural expansion, raise important questions about how vector ecology is being transformed and the new implications for Chagas disease transmission risk. METHODS: This study aimed to develop Ecological Niche Models (ENMs) to map the environmental suitability for 14 triatomine species and T. cruzi in Brazil and to evaluate the impact of landscape modifications. Environmental variables were selected based on Spearman correlation, and models were generated using Maxnet, Random Forest, and Support Vector Machines. To ensure prediction robustness, only models with a True Skill Statistic (TSS) ≥ 0.7 were considered. Based on these predictions, a risk classification was developed that integrates vector diversity and parasite presence to identify areas with higher transmission risk. RESULTS: The results revealed a significant ecological transition of the vectors, which are adapting from natural ecosystems to agroecosystems, particularly pastures and soybean cultivation, bringing the transmission cycle closer to humans. Risk analyses indicated that the Midwestern, Northern, Northeastern, and Southeastern regions are the most vulnerable, with actual risk strongly associated with modified landscapes. CONCLUSIONS: The integrated use of geotechnologies proved essential for identifying and understanding the spatial distribution of vectors and the parasite, as well as for quantifying the impact of human activity. These findings provide important insights for improving Chagas disease surveillance and control strategies, considering the environmental complexity and ecological heterogeneity involved in its transmission.Graphical abstract is mandatory for publication in this journal. Please provide the graphical abstract.The graphical abstract has been included as a attachment.
RNAi targeting ABCB1-like efflux transporters improves miticide efficacy in resistant Varroa mites.
Ricigliano VA, Fine JD, Mueller R … +6 more , Rivera L, Litsey EM, Lucadello MC, Rinkevich FD, Rector BG, Nicklisch SCT
Parasit Vectors · 2026 Jun · PMID 42237131 · Full text
BACKGROUND: The ectoparasitic mite Varroa destructor is the gravest threat to managed honeybees, and its control relies on a limited number of chemical miticides. Among these, amitraz is widely used because of its strong...
BACKGROUND: The ectoparasitic mite Varroa destructor is the gravest threat to managed honeybees, and its control relies on a limited number of chemical miticides. Among these, amitraz is widely used because of its strong efficacy against mites and relatively low toxicity to bees. However, increasing resistance to amitraz in Varroa populations threatens its long-term effectiveness. While mutations in the mite's β2 octopamine receptor are strongly associated with amitraz resistance, additional mechanisms influencing toxicant uptake and efflux are believed to also contribute. ATP-binding cassette (ABC) transporters, including ABCB1/P-glycoproteins, are well-established mediators of xenobiotic efflux and pesticide tolerance across arthropods, making them promising targets for silencing via RNA interference (RNAi) to combat miticide resistance. METHODS: We cloned a full-length Varroa ABCB1-like transporter (VdABCB1) and synthesized dsRNAs targeting its coding sequence. Adult mites were treated with dsRNA prior to amitraz exposure in laboratory bioassays. Mite survival was analyzed longitudinally, and resistance-associated β2 octopamine receptor genotypes were determined. Varroa transcriptomic responses to dsRNA were assessed by RNA sequencing. Honeybee safety was evaluated in cage assays following chronic oral dsRNA exposure, including conservative tests co-administered with a known ABC transporter substrate. RESULTS: Mites exposed to ABCB1 dsRNA showed greater amitraz-induced mortality than those treated with non-specific dsRNA. This effect was observed across multiple trials and amitraz concentrations. Transcriptomic analyses of mites revealed a significant knockdown of ABCB1-like transcripts following RNAi treatment. Chronic dietary exposure to ABCB1 dsRNA did not impact honeybee survival. Toxicity assays with ABCB1 dsRNA on its own or together with acetamiprid (ABC transporter substrate) as a high-risk interaction control showed minimal adverse effects on bees. CONCLUSIONS: RNAi suppression of Varroa ABCB1-like transporters increased amitraz mortality in resistant mites, identifying transporter-mediated efflux as a modifiable component of amitraz resistance. These findings demonstrate that targeted disruption of detoxification pathways can enhance miticide efficacy while minimizing off-target effects in bees. RNAi-based synergists therefore represent a selective resistance management strategy that could extend the effective lifespan of amitraz and other miticides relied on by the beekeeping industry.
Detritus and larval competition influence phenotypic traits, nutrient stoichiometry, and vector competence for dengue virus in Aedes aegypti.
Reyes-Torres LJ, Yee DA, Alto BW
Parasit Vectors · 2026 Jun · PMID 42231485 · Full text
BACKGROUND: Aedes aegypti is the primary vector of dengue virus (DENV), a major arboviral disease affecting human health. Variation in detritus inputs and larval competition in containers where the species develop can in...
BACKGROUND: Aedes aegypti is the primary vector of dengue virus (DENV), a major arboviral disease affecting human health. Variation in detritus inputs and larval competition in containers where the species develop can influence female Ae. aegypti phenotypic traits, nutrient content (carbon, nitrogen, C:N ratio), and elemental isotopes (δC and δN), ultimately affecting vector competence for DENV. METHODS: Female Ae. aegypti were reared under simulated urban detritus levels (low, medium, and high) and larval intra- (30:0 and 60:0) and interspecific (30:30 and 60:60) competition with Ae. mediovittatus (Ae. aegypti: Ae. mediovittatus). Aedes aegypti were offered a DENV-1-infected bloodmeal. Transmission assays were conducted, followed by assessment of susceptibility to infection, disseminated infection, and transmission rates. Body nutrient composition and isotope values were measured and analyzed in relation to phenotypic traits and vector competence for DENV-1, with male body nutrient profiles used as proxies for females where sample sizes were limited. RESULTS: Longer development time and reduced wing length in Ae. aegypti were associated with low detritus. Wing length increased under interspecific competition with Ae. mediovittatus but decreased under intraspecific competition. Higher δN values in Ae. aegypti body tissues were associated with greater detritus availability and with interspecific competition. DENV-1 dissemination exhibited a nonlinear relationship with δN, showing high dissemination at low δN, the lowest dissemination at intermediate δN, and an increase at higher δN. Vector competence for DENV-1 was reduced under conditions of low detritus and low intraspecific competition (30:0). High interspecific competition combined with high detritus negatively affected Ae. aegypti phenotypic traits and reduced DENV-1 vector competence. Under the most extreme conditions (high interspecific competition, 60:60, and high detritus), Ae. aegypti failed to reach adulthood. At intermediate detritus levels for the same density, Ae. aegypti exhibited high rates of DENV-1 disseminated infection. CONCLUSIONS: This research underscores the importance of larval crowding and nutritional availability experienced during the immature stages of Ae. aegypti on adult nutrient stoichiometry and DENV-1 infection. These findings suggest the potential use of δN as a tool to assess how larval nutritional and competitive environments shape dengue vector competence, with implications for understanding and predicting Ae. aegypti-driven DENV-1 dynamics in urban and suburban areas. Interpretations should consider that female nutrient estimates were partially inferred from male data due to low female sample sizes, survivorship was estimated assuming a 1:1 sex ratio, and some high-mortality treatments lacked surviving adults.
Adaptive restructuring of the microbiota promotes overwintering survival of the tick Dermacentor silvarum.
Pei T, Nwanade CF, Wang Z … +4 more , Liu Z, Dai Y, Zhang X, Yu Z
Parasit Vectors · 2026 Jun · PMID 42231482 · Full text
BACKGROUND: Dermacentor silvarum is a medically important tick species in temperate regions of Asia that must survive prolonged cold exposure during winter. However, the impact of low-temperature stress on its microbial...
BACKGROUND: Dermacentor silvarum is a medically important tick species in temperate regions of Asia that must survive prolonged cold exposure during winter. However, the impact of low-temperature stress on its microbial community and the potential functional implications for overwintering remain poorly understood. METHODS: Adult ticks of D. silvarum were subjected to controlled low-temperature treatments (8, 4, 0, and -4 °C) for 7 days, with ticks maintained at 27 °C serving as controls. The bacterial 16S rRNA (V4 region) and fungal ITS1 regions were amplified and sequenced using the Illumina NovaSeq PE250 platform. Bioinformatics analyses were performed to assess microbial diversity, community composition, and predicted functional profiles. RESULTS: Cold exposure significantly altered both bacterial and fungal community structures, increasing overall microbial diversity. Proteobacteria and Actinobacteriota dominated the bacterial assemblages, whereas the Ascomycota and Basidiomycota were the predominant fungal phyla. A marked enrichment of psychrotolerant and metabolically versatile genera, including Pseudomonas, Sphingomonas, and Trichosporon, alongside a decline in the nutrient-provisioning symbiont Coxiella were observed in cold-treated ticks. Functional prediction suggested that the enriched taxa are potentially involved in antioxidative defense, cryoprotectant biosynthesis, membrane stabilization, and detoxification processes. CONCLUSIONS: The results demonstrate that low temperature drives a comprehensive reorganization of the microbiota in D. silvarum. The increase in psychrotolerant and detoxifying microbes likely reflects an adaptive host-microbe interaction that enhances tolerance to cold, oxidative, and osmotic stress, thereby promoting overwinter survival of the ticks. These findings provide new insights into the ecological resilience of tick-associated microbiomes and the symbiotic mechanisms underlying vector adaptation to climatic challenges.
Protein arginine methyltransferase 5 is essential for virulence in Toxoplasma gondii.
Xu L, Liang H, Bai S … +5 more , Xu R, Liu B, Xu X, Xu X, Liu M
Parasit Vectors · 2026 Jun · PMID 42231480 · Full text
BACKGROUND: Protein arginine methyltransferase 5 (PRMT5) is a key enzyme responsible for catalyzing symmetric dimethylarginine (SDMA) modifications and plays crucial roles in epigenetic regulation, transcription, and cel...
BACKGROUND: Protein arginine methyltransferase 5 (PRMT5) is a key enzyme responsible for catalyzing symmetric dimethylarginine (SDMA) modifications and plays crucial roles in epigenetic regulation, transcription, and cell cycle progression in eukaryotes. Although our previous study determined the expression and cellular localization of PRMT5 in tachyzoites and bradyzoites, and confirmed its type II PRMT activity, its functional significance in Toxoplasma gondii remains entirely uncharacterized. METHODS: This study aimed to explore the biological functions of PRMT5 in T. gondii. The prmt5 gene was disrupted in the type I RH strain using the clustered regularly interspaced short palindromic repeats (CRISPR) Cas9 system. The biological roles of PRMT5 were evaluated via multiple functional assays, including plaque formation, intracellular proliferation, host cell invasion, virulence, and tachyzoite to bradyzoite conversion assays. RNA sequencing was further performed to profile transcriptomic alterations induced by prmt5 disruption. RESULTS: Phenotypic characterization revealed that the ∆prmt5 strain exhibited reduced symmetric dimethylarginine (SDMA) levels as well as severe defects in plaque formation, invasion, intracellular replication, and bradyzoite differentiation. Accordingly, the virulence of the ∆prmt5 strain was dramatically attenuated, as all infected BALB/c mice survived over a 10-day period, in stark contrast to the 100% mortality observed in the wild-type control group within 10 days. RNA-sequencing analysis uncovered the molecular basis for these phenotypes, demonstrating that prmt5 disruption leads to global transcriptional dysregulation. Specifically, we identified a significant downregulation of genes associated with motor protein function and fatty acid metabolism pathways. CONCLUSIONS: Our research has demonstrated that PRMT5 plays a critical role in the proliferation, survival, pathogenicity, and regulation of gene expression in Toxoplasma gondii.
Polyunsaturated fatty acid and oxylipin profiles of Angiostrongylus cantonensis during cerebral-to-pulmonary migration illuminate parasite and host microenvironmental lipid signatures.
Tang Z, Lai J, Song Y … +4 more , Li S, Xiao L, Feng Y, Yuan D
Parasit Vectors · 2026 Jun · PMID 42231446 · Full text
BACKGROUND: Metabolic streamlining as a consequence of parasitism has resulted in the loss of lipid biosynthetic genes in nematodes. Angiostrongylus cantonensis, a zoonotic neurotropic parasite that causes eosinophilic m...
BACKGROUND: Metabolic streamlining as a consequence of parasitism has resulted in the loss of lipid biosynthetic genes in nematodes. Angiostrongylus cantonensis, a zoonotic neurotropic parasite that causes eosinophilic meningitis in mammals, completes a complex migration through the rat brain before maturing in the pulmonary arteries. Polyunsaturated fatty acids (PUFAs) and their bioactive metabolites (oxylipins) are known to modulate nematode survival; however, their abundance and endogenous biosynthetic capacity in A. cantonensis remain elusive. METHODS: We integrated comparative genomics, stage-specific transcriptomics, and lipidomics to reconstruct the expression patterns of the biosynthetic enzymes in A. cantonensis and characterize their dynamic PUFA and oxylipin profiles during the neuro-pulmonary transition from brain-residing fourth-stage (L4) to lung-migrating L5 larvae. RESULTS: Genomic and transcriptomic analyses revealed a streamlined biosynthetic repertoire in A. cantonensis. The worm lacks Δ6 desaturase and canonical cyclooxygenase (COX), lipoxygenase (LOX), and cytochrome P450 (CYP) enzymes, and expresses only residual levels of ptges2 and lta4h, which are markedly lower than those in free-living Caenorhabditis elegans across developmental stages. Using liquid chromatography-tandem mass spectrometry, L4-L5 larvae residing in the rat brain maintained stable PUFA and oxylipin profiles. In contrast, L5 larvae migrating to the lungs accumulated n-6 PUFAs and anti-inflammatory hydroxy eicosatetraenoic acids, epoxy eicosatrienoic acids and hydroxy docosahexaenoic acids, concurrent with reduced levels of pro-inflammatory prostaglandins and 5-oxo-eicosatetraenoic acid. CONCLUSIONS: These stage- and tissue-specific lipidomic shifts correlate with distinct host microenvironments encountered during migration. These findings provide a foundation for understanding the evolutionary adaptation of lipid metabolism in parasitic nematodes.
Bird trematodes in the era of rapid environmental change.
Heneberg P
Parasit Vectors · 2026 Jun · PMID 42231382 · Full text
BACKGROUND: Rapid climate warming, hydrological regulation, eutrophication, pollution, and habitat conversion are reshaping aquatic ecosystems in which bird trematodes complete complex life cycles. Because birds act as d...
BACKGROUND: Rapid climate warming, hydrological regulation, eutrophication, pollution, and habitat conversion are reshaping aquatic ecosystems in which bird trematodes complete complex life cycles. Because birds act as definitive hosts, dispersal agents, and trophic links among habitats, we provide a bird-focused review aimed at improving our understanding of how environmental change affects trematode transmission, community structure, and biogeography. METHODS: We reviewed evidence on avian trematodes across freshwater, coastal, artificial wetland, agricultural, and high-latitude systems. The review integrates mechanistic studies of temperature-dependent intramolluscan development, cercarial emergence, survival, and infectivity with field studies documenting changes in hydrology, intermediate-host availability, bird phenology, habitat use, and trematode community composition. RESULTS: Environmental change affects bird trematodes through multiple interacting pathways. Warming can accelerate cercarial production and shift emergence phenology, but effects are nonlinear and stage-specific because higher temperatures may also reduce cercarial survival or disrupt synchrony with bird hosts. Hydrological alteration, eutrophication, and pollution alter snail and second intermediate host communities, creating spatially heterogeneous transmission mosaics. Changes in bird distribution, migration timing, diet, and use of artificial habitats can either maintain transmission, increase exposure to generalist trematodes, or interrupt complex life cycles. Long-term and molecular studies indicate that disturbed systems may lose specialist trematodes, become functionally homogenized, or conceal cryptic lineage turnover under apparently stable morphology-based species lists. CONCLUSIONS: Bird-trematode systems respond to environmental change in context-dependent ways rather than through uniform increases or decreases in transmission. Birds can amplify, disperse, buffer, or interrupt trematode life cycles depending on host competence, movement, habitat connectivity, and intermediate-host availability. Future surveillance should combine stage-specific parasite sampling, molecular identification, bird movement data, and remote sensing to improve forecasts of trematode redistribution and transmission risk under ongoing environmental change.
Canine leishmaniosis on Favignana Island: a prospective observational study on infection dynamics, clinical outcomes and field safety in dogs receiving both vaccination (LETIFEND) and an antifeeding collar (SCALIBOR).
Foglia Manzillo V, Oliva G, Castelli G … +7 more , Bruno F, Rosenthal R, Montagnaro S, Balestrino I, La Rocca C, Colombo L, Gizzarelli M
Parasit Vectors · 2026 May · PMID 42218505 · Full text
BACKGROUND: Canine leishmaniosis (CanL) is endemic in Italy and is an important veterinary and public health concern. Integrated preventive strategies combining vaccination and vector control are recommended in endemic a...
BACKGROUND: Canine leishmaniosis (CanL) is endemic in Italy and is an important veterinary and public health concern. Integrated preventive strategies combining vaccination and vector control are recommended in endemic areas, and field data supporting the safety and effectiveness of this concurrent use are limited. METHODS: A longitudinal field study conducted on Favignana Island (Sicily, Italy) evaluated the concurrent use of a vaccine (LETIFEND, Leti) and sandfly repellent collar (SCALIBOR, MSD Animal Health). Client-owned dogs (154) were prescreened by clinical examination, serology, quantitative polymerase chain reaction (qPCR) and serological testing (SNAP4Dx Plus, IDEXX). Leishmania-negative dogs (62) were enrolled in the study, vaccinated, fitted with a deltamethrin-impregnated sandfly repellent collar, and monitored every 6 months for 24 months (2 transmission seasons). Follow-up evaluations included clinical examination, serological testing (SNAP Leish Test, IDEXX), and conjunctival swab qPCR; sera were stored for subsequent indirect immunofluorescence antibody testing (IFAT). After 12 months, dogs that remained negative received a booster vaccination and replacement collar. RESULTS: The proportion of dogs positive for CanL in the prescreen was 12.3% (19/154). Two dogs in the enrolled group (3.22%, 2/62) developed clinical signs compatible with CanL and tested positive (SNAPLeish,IDEXX) during the study. IFAT testing of enrolled dogs found low antibody titres in nine additional clinically healthy dogs corresponding to a cumulative infection incidence of 14.5% and an incidence density of 0.61% per dog-month. No local or systemic adverse reactions associated with the combined preventive protocol were recorded. CONCLUSIONS: Concurrent vaccination (LETIFEND, Leti) and preventive collar administration (SCALIBOR, MSD Animal Health) resulted in no adverse events, although there was a low incidence of clinical CanL and seroconversion over two consecutive transmission seasons. These findings support the use of integrated preventive strategies to limit the development of clinical disease in dogs living in endemic areas.
Molecular detection of zoonotic pathogens in fleas collected from dogs and cats in Portugal.
Pereira A, Cruz A, Cruz J … +3 more , Garcia-Dios D, Novo T, Maia C
Parasit Vectors · 2026 May · PMID 42218469 · Full text
BACKGROUND: Fleas are common ectoparasites of companion animals and key vectors of pathogens of veterinary and zoonotic relevance. Although flea infestations are highly prevalent in dogs and cats in Portugal, nationwide...
BACKGROUND: Fleas are common ectoparasites of companion animals and key vectors of pathogens of veterinary and zoonotic relevance. Although flea infestations are highly prevalent in dogs and cats in Portugal, nationwide data on flea-borne pathogens are limited. This study aimed to estimate the prevalence and characterize the molecular diversity of Bartonella spp., Rickettsia spp., and Dipylidium caninum in fleas collected from dogs and cats in mainland Portugal, and to identify associated epidemiological factors. METHODS: Fleas collected from dogs and cats across mainland Portugal were screened using conventional polymerase chain reaction (PCR) assays targeting the 16S-23S ribosomal RNA (rRNA) intergenic spacer region of Bartonella spp., the ompB gene of Rickettsia spp., and the 28S rRNA gene region of D. caninum. Positive amplicons were sequenced and analyzed phylogenetically. Associations between pathogen detection and epidemiological variables, including host species, host lifestyle, flea species, and geographic region, were evaluated using multivariable logistic regression models. RESULTS: A total of 1261 fleas were analyzed, with 24.7% positive for at least one pathogen. Bartonella spp. DNA was detected in 8.3% of fleas and was significantly more frequent in fleas from cats, particularly stray/sheltered animals, with regional differences also observed. Identified species included B. clarridgeiae, B. henselae, and B. rochalimae. Rickettsia spp. DNA was detected in 16.2% of fleas, predominantly in Ctenocephalides felis, with flea species, host species, and geographic region identified as independent predictors of positivity. Most sequences corresponded to R. felis, while R. asembonensis and Candidatus R. senegalensis, the latter reported for the first time in Europe, were also identified. Dipylidium caninum DNA was detected in 1.8% of fleas, all C. felis, with both canine- and feline-associated genotypes circulating in fleas from dogs and cats. Co-detection of pathogen DNA occurred in 2.1% of fleas, mostly Bartonella spp./Rickettsia spp. CONCLUSIONS: Fleas infesting companion animals in Portugal frequently harbor pathogens of veterinary and zoonotic relevance, with C. felis playing a central role in pathogen circulation at the human-animal interface. These findings reinforce the need for sustained surveillance and effective ectoparasite control within a One Health framework to reduce pathogen circulation and mitigate risks to both animal and public health.
Updated Canine Leishmaniosis Working Group recommendations for leishmaniosis in dogs: Q&A on clinical management.
Roura X, Paltrinieri S, Cortadellas O … +6 more , Fondati A, Lubas G, Zini E, Otranto D, Benali SL, Zatelli A
Parasit Vectors · 2026 May · PMID 42216067 · Full text
Canine leishmaniosis is an important vector-borne disease and a threat to dogs worldwide. Disease data are continuously being collected, with a consequent increase in the number of publications. This article provides pra...
Canine leishmaniosis is an important vector-borne disease and a threat to dogs worldwide. Disease data are continuously being collected, with a consequent increase in the number of publications. This article provides practical guidelines for veterinary practitioners on the diagnosis, treatment, and prevention of leishmaniosis in dogs. These Canine Leishmaniosis Working Group (CLWG) recommendations aim to provide practical answers to the most common questions on the clinical management of this disease.
Integrating molecular tools into leishmaniosis surveillance: evaluation of a commercial qPCR kit in sand fly vectors.
Dehesa-García B, Alonso H, Ruiz-Zarzuela I … +8 more , Cervera-Acedo C, Martínez-Durán D, Delacour S, Castillo JA, Oteo JA, Collantes F, Peris MP, Ruiz-Arrondo I
Parasit Vectors · 2026 May · PMID 42216021 · Full text
BACKGROUND: Leishmaniosis is a zoonotic disease caused by protozoan parasites of the Leishmania genus, primarily transmitted through the bites of infected female phlebotomine sand flies. Leishmania infantum is the most p...
BACKGROUND: Leishmaniosis is a zoonotic disease caused by protozoan parasites of the Leishmania genus, primarily transmitted through the bites of infected female phlebotomine sand flies. Leishmania infantum is the most prevalent Leishmania species in the Mediterranean Region, affecting both humans and animals, mainly dogs. Integrated surveillance strategies, including xenomonitoring, are essential for early detection and cost-effective control in endemic areas. In 2021, an increase in human leishmaniosis cases was reported in the Region of Murcia (Spain), prompting an intensified entomological surveillance effort aimed at assessing Leishmania prevalence in vector populations. Phlebotomine sand flies were collected and analysed to determine the circulation of Leishmania spp. in the area. Subsequently, these field-collected samples were used to evaluate the diagnostic performance of a commercial real-time PCR (qPCR) kit designed for the detection of Leishmania DNA. METHODS: A comparative-retrospective analysis was carried out at the Parasitology Laboratory of the Department of Animal Pathology, University of Zaragoza. A total of 314 DNA extracts from pooled female sand fly samples, collected in urban and peri-urban areas of 29 municipalities in the Region of Murcia near recently reported human leishmaniosis cases (2021-2022), were analysed. Sampling was conducted in June and September 2023 using CO-baited light traps to investigate the presence of Leishmania spp. in sand flies. The performance of the VIASURE qPCR assay (CerTest Biotec, Zaragoza, Spain) was assessed against a structured reference method consisting of an in-house qPCR assay, conventional PCR followed by Sanger sequencing and a SYBR Green qPCR used to resolve discordant results. RESULTS: Of the 314 pooled samples analysed, 21 tested positive for Leishmania spp. using the reference methods, while the VIASURE assay identified 23 Leishmania spp.-positive pooled samples. After resolving discrepancies, the obtained analytical sensitivity and specificity were 0.95 (95% confidence interval [CI] 0.76-0.99) and 0.99 (95% CI 0.97-0.99), respectively. CONCLUSIONS: The commercial VIASURE qPCR assay showed high concordance with established molecular methods and demonstrated reliable performance for detecting Leishmania DNA in sand fly vectors. To our knowledge, this is the first study to specifically validate a commercially available qPCR kit in phlebotomine sand flies. These findings support its potential utility in entomological surveillance programs and public health interventions in leishmaniosis-endemic regions.
Publisher Correction: Report of the Seventh Post-Kala-Azar Dermal Leishmaniasis Consortium Meeting, Kolkata, India, 28-29 November 2024.
Chatterjee M, Sengupta R, Cloots K … +1 more , Zijlstra EE
Parasit Vectors · 2026 May · PMID 42210299 · Full text
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Can dual active ingredient Interceptor® G2 insecticide-treated net (ITN) replace indoor residual spraying (IRS) efficiently? A case study in Sakassou, Côte d'Ivoire.
Chabi J, Shirima GS, Masanja B … +13 more , Coleman S, N'Guessan Gbalegba CG, Kouassi BL, N'Guessan Broudje BR, Ako Edi CV, Yokoly FN, Adimi WO, Kouame RA, Anian V, Kyerematen R, Egyir-Yawson A, Kiware S, Dadzie SK
Parasit Vectors · 2026 May · PMID 42210234 · Full text
BACKGROUND: Following three successful rounds of indoor residual spraying (IRS) implementation in the district of Sakassou (Côte d'Ivoire), IRS was withdrawn and replaced by insecticide-treated nets (ITNs). This study ev...
BACKGROUND: Following three successful rounds of indoor residual spraying (IRS) implementation in the district of Sakassou (Côte d'Ivoire), IRS was withdrawn and replaced by insecticide-treated nets (ITNs). This study evaluated the entomological and epidemiological impacts of Interceptor (IG2) ITNs distributed in Sakassou to determine whether the protection offered by IG2 ITNs was adequate to suppress malaria transmission post-IRS withdrawal. METHODS: This study is a quasi-experimental evaluation using historical data and additional data collections on entomological indicators and malaria incidence to assess malaria transmission trends in Sakassou. The vector control optimization model was adapted to evaluate the effectiveness of the IRS and IG2 ITN deployment on malaria transmission dynamics. Additionally, we used an interrupted time series model to analyze routinely reported malaria cases in the District Health Information Management System (DHIS2) to determine the epidemiological impact of both interventions. Counterfactual trends were generated for the post-IRS withdrawal period during which IG2 ITNs were distributed. RESULTS: The results showed a 55.4% (95% CI 48.3-62.4%) reduction in the human biting rate (HBR) when IRS was deployed and 48.8% (95% CI 42.8-54.6%) when IG2 ITNs were distributed, compared with standard pyrethroid-only nets. No statistical difference was recorded between the HBR of IG2 ITNs and IRS (P = 0.164) during the implementation of IG2 ITNs and the counterfactual of IRS. Similarly, IRS resulted in a 64.7% (95% CI 56.6-72.8%) decline in EIR while IG2 ITNs resulted in a comparable reduction of 61.9% (95% CI 54.2-69.6% ;P = 0.616) over the same period. Furthermore, a 26% reduction in malaria cases was recorded immediately after spraying (IRR = 1.02; 95% CI 1.00-1.04; P = 0.005) with cumulative impact over time and spray rounds and was similar to IG2 performance (IRR = 1.03; CI 1.00-1.07; P = 0.040). CONCLUSIONS: The study findings suggest that IG2 ITNs provided entomological efficacy comparable to clothianidin-based IRS but could not adequately suppress malaria cases after IRS withdrawal, possibly due to plastic-vector feeding behavior and late timing of IG2 deployment. Overall, the study shows how the dynamics of malaria transmission and operational decisions could impact the effectiveness of both IRS and ITNs as vector control tools. These findings provide key information for malaria programs and policymakers to consider when deploying vector control interventions as countries work toward malaria elimination.
Toll-like receptor-mediated innate immune response correlate with the pathogenicity of Eimeria tenella infection in SPF chickens.
Zhu H, Zheng G, Wang D … +7 more , Zhang Q, Han Y, Wang S, Wang Q, He H, Zhang L, Hu J
Parasit Vectors · 2026 May · PMID 42204750 · Full text
BACKGROUND: Eimeria tenella, one of the most virulent causative agents of coccidiosis, specifically colonizes the cecum and imposes substantial economic losses on the poultry industry. Toll-like receptors (TLRs), key med...
BACKGROUND: Eimeria tenella, one of the most virulent causative agents of coccidiosis, specifically colonizes the cecum and imposes substantial economic losses on the poultry industry. Toll-like receptors (TLRs), key mediators of the innate immune response, initiate rapid defense against invading parasites. However, their roles during E. tenella infection remain poorly defined. METHODS: In this study, coccidiosis infection parameters (cecal lesions, oocyst output, and clinical signs) were monitored, and the expression profiles of 10 chicken TLRs (chTLRs) and related immune genes in the cecum and spleen of E. tenella-infected chickens were characterized at multiple time points using quantitative real-time polymerase chain reaction (PCR) and histopathological analysis. Spearman correlation analysis was performed to evaluate associations between TLR expression and pathogenicity parameters. RESULTS: Infected chickens exhibited marked clinical signs, although no mortality occurred in either group. Cecal lesions became apparent by 96 h post-infection (hpi), peaking at 144 hpi, and were accompanied by significant epithelial necrosis and extensive inflammatory cell infiltration. Most TLR genes showed distinct expression patterns between the cecum and spleen: cecal TLRs were upregulated during the middle phase (24-72 hpi) of infection, whereas splenic TLRs were downregulated in later stages (96-168 hpi). Key proinflammatory cytokines-interleukin (IL)-1β, tumor necrosis factor (TNF)-α, and interferon (IFN)-γ-were elevated in the cecum during early infection but declined in the spleen during later phases. Infection also induced dynamic expression changes in the downstream signaling molecules myeloid differentiation factor 88 (MyD88) and nuclear factor-kappa B (NF-κB) p65 in both tissues. Spearman correlation analysis revealed that, in the cecum, chTLR7 positively correlated with both oocyst output and lesion scores, whereas chTLR2a positively correlated with lesion scores. By contrast, chTLR1a, chTLR1b, chTLR15, and chTLR21 negatively correlated with oocyst output. In the spleen, chTLR15 and chTLR21 positively correlated with oocyst output, while chTLR5 uniquely and negatively correlated with lesion scores. CONCLUSIONS: These findings identify both proinflammatory and potentially protective TLR pathways in subclinical coccidiosis.
Environmental factors influencing Culicoides vectors of Bluetongue in northwestern Spain: abundance, phenology and epidemiological risk.
Polina A, Martínez-Barciela Y, Ruiz-Arrondo I … +2 more , Estrada R, Garrido J
Parasit Vectors · 2026 May · PMID 42204727 · Full text
BACKGROUND: The genus Culicoides comprises several vectors of the Bluetongue virus (BTV) affecting livestock and other ruminants. The historical occurrence and recent re-emergence of this disease in Galicia (NW Spain) ma...
BACKGROUND: The genus Culicoides comprises several vectors of the Bluetongue virus (BTV) affecting livestock and other ruminants. The historical occurrence and recent re-emergence of this disease in Galicia (NW Spain) make it essential to identify the vector species present in the region, determine the factors influencing their abundance, analyse their seasonal activity period and identify areas of highest epidemiological risk. METHODS: A total of 2009 light-trap collections targeting Culicoides were conducted at representative sites across Galicia between 2008 and 2012. A subset of the 2009 dataset was used to analyse species phenology and epidemiological risk. Several climatic and environmental factors were obtained from different sources to determine their relationship with the abundance of the identified potential BTV vectors through Negative Binomial Generalized Linear Models (NBGLMM). RESULTS: Five potential BTV vectors were identified in the region: Culicoides obsoletus s.l., C. punctatus, C. newsteadi, C. pulicaris and C. imicola. NBGLMM provided a good fit for the Obsoletus complex (Rc = 0.68) and for C. punctatus (Rc = 0.54). Non-linear correlations were observed between Obsoletus complex abundance and environmental variables. High temperatures 6 months prior to the collection date were associated with a decrease in the abundance of the Obsoletus complex, whereas higher mean minimum temperatures 28 days prior to sampling, NDVI and seasonality had a positive impact. Culicoides punctatus abundance was negatively correlated with higher mean maximum temperatures 6 months before sampling, while higher mean minimum temperatures 2 months prior to collection, altitude and Csb-type climate were positively associated. The vector activity period (VAP) averaged 23.9 ± 6.0 weeks per year. The deterministic basic reproduction number R indicated a potential BTV transmission risk period of 16.5 ± 7.0 weeks annually, whereas the Monte Carlo approach estimated a period of 14.8 ± 5.6 weeks per year. This means a period approximately 31.0-38.1% shorter than the VAP, suggesting that periods of vector presence do not necessarily translate into sustained disease transmission potential. CONCLUSIONS: This research provides valuable insights into the ecological determinants of BTV vectors abundance under Atlantic climate conditions. These findings are crucial for understanding disease transmission dynamics and improving vector control strategies. By integrating climatic characteristics and identifying areas of highest epidemiological risk, public health interventions and management measures can become more targeted and efficient.
Mosquito- and biting-midge-borne arboviruses in Western Yunnan's border region, China.
Yang Y, He Y, Zhu Y … +6 more , Wu J, Zhao K, Li Z, Yang Z, Yin J, Wang J
Parasit Vectors · 2026 May · PMID 42204648 · Full text
BACKGROUND: Arboviruses that infect humans and other mammals pose significant public health challenges worldwide, particularly in developing countries. The border region of Yunnan Province, a key entry point for imported...
BACKGROUND: Arboviruses that infect humans and other mammals pose significant public health challenges worldwide, particularly in developing countries. The border region of Yunnan Province, a key entry point for imported arboviruses into China, is characterized by a subtropical climate and a rich diversity of mosquito and biting midge species, making it a high-risk area for arbovirus transmission. While some studies have focused on mosquito-borne viruses in this region, research on midge-borne viruses, particularly those with zoonotic relevance, remains limited. This study aimed to systematically investigate the diversity of arboviruses in both vector groups and to address critical gaps in the assessment of spillover risk. METHODS: In July 2018, mosquitoes and biting midges were collected from Mangshi, Yingjiang, Lushui, and Tengchong in the border region of western Yunnan Province, China. Following morphological classification, specimens were pooled for virus isolation using BHK-21 and C6/36 cells. Viral isolates were identified by reverse transcription polymerase chain reaction (RT-PCR) using virus-specific primers, and sequence analyses were performed using Clustal X, DNASTAR, and MEGA-X. RESULTS: A total of 8581 mosquitoes (8 species in 4 genera) and 18,298 biting midges (19 species) were collected. Culex tritaeniorhynchus dominated the mosquito populations in Mangshi (92.11%) and Yingjiang (97.23%), whereas Anopheles sinensis was predominant in Lushui (44.01%) and Tengchong (59.23%). Biting midge composition varied among regions, with Culicoides tainanus predominating in Mangshi (59.79%) and C. arakawai in Lushui (48.11%). In total, 189 viral strains representing 10 virus species in 8 families were isolated. Tibet orbivirus (TIBOV) was the most widely distributed virus (83 strains), occurring in all four regions, with biting midges accounting for most isolates (50/83 strains). Biting midges also contributed substantially to arbovirus diversity, yielding 13 Yunnan orbivirus (YUOV) strains, 4 Banna virus (BAV) strains, and the only Akabane virus (AKAV) isolate. In contrast, mosquitoes mainly harbored insect-specific viruses (ISVs), including 53 Manglie virus (MAV) strains. Novel viruses such as Culex-originated Tymoviridae-like virus (CuTLV) and Armigeres iflavirus (ArIFV) were identified in both vectors. These findings highlight biting midges as important yet understudied vectors, harboring distinct zoonotic and vector-associated viruses in this border region. CONCLUSIONS: This study demonstrates the circulation of diverse arboviruses in both mosquitoes and biting midges in the border region of western Yunnan Province. Notably, biting midges harbored multiple arboviruses, including several viruses with zoonotic potential or known pathogenicity, such as Tibet orbivirus (TIBOV), Yunnan orbivirus (YUOV), Banna virus (BAV), and Akabane virus (AKAV). These findings emphasize the important role of biting midges, alongside mosquitoes, in maintaining and potentially spreading these viruses in the local arboviral ecosystem. The study underscores the importance of including midge-borne viruses in future surveillance efforts, as they contribute substantially to the diversity and epidemiology of arboviral transmission in the region, with potential implications for public health.
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