Parasit Vectors [JOURNAL]
Sun
200 papers
Evaluation of the diagnostic performance of a commercial ELISA based on two recombinant antigens for the diagnosis of Strongyloides stercoralis infection.
Guevara ÁG, Vicuña Y, Anselmi M … +6 more , Marquez M, Huerlo FR, Valerio M, Mazzi C, Tamarozzi F, Buonfrate D
Parasit Vectors · 2026 Jul · PMID 42401974 · Full text
BACKGROUND: The WHO guideline for the public health control of Strongyloides stercoralis recommends the deployment of Baermann or agar plate culture to estimate the infection prevalence. However, the guideline includes t...
BACKGROUND: The WHO guideline for the public health control of Strongyloides stercoralis recommends the deployment of Baermann or agar plate culture to estimate the infection prevalence. However, the guideline includes the possible use of antibody-based assays, which might be preferred in some countries. An ELISA based on two recombinant antigens (Strongy Detect ELISA by InBios), performed on dried blood spots (DBS), demonstrated suitable for use in a diagnostic study carried out in remote areas of Ecuador ("ESTRELLA"). A new version of that assay, which aimed at improving specificity according to the indications reported in the target product profile (TPP) for the diagnostics for S. stercoralis, was recently made available in the market. Aim of this study was to compare the performance of the two versions of that ELISA. METHODS: The DBS collected in the context of the study in Ecuador were tested with the new ELISA. Sensitivity, specificity, positive and negative predictive values (PPV and NPV, respectively) were calculated with Bayesian Latent Class Analysis (BLCA). Bayesian estimates were reported as posterior medians with corresponding 95% credible intervals (CrI). Test agreement was calculated with both BLCA and Cohen's kappa. RESULTS: Sensitivity was 66.7% (95% CrI 52.8-80.6) for the new assay, versus 78.8% (95% CrI 66.7-89.2) of the old version (posterior probability that the new test had higher sensitivity = 0.1). Specificity was markedly higher for the new version compared to the previous assay: 98.8% (95% CrI 97.9-99.4) versus 90.1% (95% CrI 87.6-92.4), respectively (posterior probability that the new test had higher specificity = 1). PPV for the new ELISA proved good at all prevalence values considered, going from 80.1% (CrI 67.0-89.4%) when prevalence was 7% to 95.8% (92.5%, 97.9%) with 30% prevalence. The agreement was fair (Cohen's kappa 0.38; 95% CI 0.26-0.49). CONCLUSIONS: The new version of the Strongy Detect ELISA demonstrated improved specificity with a moderate reduction in sensitivity compared to the previous version, meeting the TPP requirements in terms of diagnostic performance. Adherence with the other TPP requirements was out of the scope of this study, and should be assessed elsewhere.
Trouble from the tiger: first detection of dengue virus in Aedes albopictus in Australia during a 2024 dengue outbreak on Masig Island.
Muzari MO, Graham MC, Ehlers G … +5 more , Bellwood R, Davis J, Peniyamina D, Devine GJ, Johnson BJ
Parasit Vectors · 2026 Jul · PMID 42401942 · Full text
BACKGROUND: Dengue is not endemic in Australia and outbreaks occur occasionally after viraemic travellers visit parts of Queensland where dengue vectors are prevalent. Prior to 2016, Aedes aegypti was the primary vector...
BACKGROUND: Dengue is not endemic in Australia and outbreaks occur occasionally after viraemic travellers visit parts of Queensland where dengue vectors are prevalent. Prior to 2016, Aedes aegypti was the primary vector of dengue in Australia. However, several dengue outbreaks have occurred more recently on islands in the Torres Strait region where Ae. aegypti has been displaced by Aedes albopictus following its first detection in the islands in 2005. METHODS: In November 2024, adult female Ae. albopictus were collected during a dengue outbreak on Masig Island where Ae. aegypti is now absent after displacement by Ae. albopictus. Collected mosquitoes were pooled and screened for the presence of dengue virus by qRT-PCR and direct RNA sequencing. RESULTS: Dengue virus RNA was detected by qRT-PCR in 9 of 12 mosquito pools. RNA sequencing of three positive pools confirmed the virus as belonging to dengue serotype 3 (DENV-3), consistent with the clinical serotype identified during the 2024 outbreak. Sequencing further detected four insect-specific viruses, including Bio Sioux River virus, reported in Australia for the first time. CONCLUSIONS: These results represent the first detection and whole genome sequencing of dengue virus in Ae. albopictus collected in Australia. The detection of DENV-3 RNA in Ae. albopictus during a concurrent outbreak of the same serotype in the absence of Ae. aegypti supports the ability of Ae. albopictus to drive independent dengue outbreaks. The findings confirm the risk of dengue outbreaks in mainland Australia if Ae. albopictus were to invade and expand beyond its current distribution in the Torres Strait.
Mitochondrial COI and 16S rDNA barcoding improve species delimitation of ixodid ticks in Peninsular Malaysia.
Husin NA, Low VL, AbdulRahim MHS … +7 more , Abdullah Halim MR, AbdulHalim AA, Mohd-Redzuan MAA, Jiliun EA, Mohd Kharip Shah AK, Makepeace BL, Ya'cob Z
Parasit Vectors · 2026 Jul · PMID 42400034 · Full text
BACKGROUND: Hard ticks (Acari: Ixodidae) are major vectors of zoonotic pathogens affecting humans and animals. Accurate species identification is essential for surveillance and disease risk assessment but is often hinder...
BACKGROUND: Hard ticks (Acari: Ixodidae) are major vectors of zoonotic pathogens affecting humans and animals. Accurate species identification is essential for surveillance and disease risk assessment but is often hindered by morphological similarity and intraspecific variation. In Malaysia, tick studies have largely relied on morphology or single-gene barcoding, with limited taxonomic and geographic coverage. METHODS: This study applied a multilocus mitochondrial approach using cytochrome c oxidase I (COI) and 16S ribosomal DNA (rDNA) to evaluate species boundaries among ixodid ticks from Peninsular Malaysia. Ticks were collected from wild and domestic hosts between 2022 and 2023. A total of 319 specimens representing 14 morphologically defined species were analysed using COI and 16S rDNA sequencing, with additional reference sequences retrieved from GenBank for comparative analyses. Phylogenetic reconstruction, barcode gap assessment, and four species delimitation methods (ASAP, ABGD, bPTP, and GMYC) were employed to assess genetic divergence and identification accuracy. RESULTS: Molecular analyses were largely congruent with morphological identification. Distance-based delimitation methods (ASAP and ABGD) recovered operational taxonomic units (OTUs) largely consistent with morphologically defined species, whereas tree-based approaches (bPTP and GMYC) inferred substantially higher numbers of OTUs, reflecting sensitivity to intraspecific mitochondrial structuring. These additional subdivisions are interpreted conservatively as population-level genetic differentiation rather than evidence of distinct species. Clear barcode gaps were observed for COI and the concatenated COI + 16S rDNA datasets, whereas partial overlap occurred with 16S rDNA alone. COI demonstrated the highest and most consistent performance for routine species identification, while concatenated datasets improved phylogenetic resolution but reduced assignment clarity under strict barcoding criteria. CONCLUSIONS: Overall, COI remains the most effective mitochondrial marker for routine species identification of ixodid ticks in Peninsular Malaysia. These findings highlight the value of integrative approaches combining morphology and molecular data to strengthen tick taxonomy and support surveillance of tick-borne pathogens in the region.
Immune-reproductive cross talk in mosquitoes: molecular pathways and energy homeostasis.
Zheng F, Zhao C, Li X … +5 more , Liu T, Wang S, Liu Z, Yu S, Wang Y
Parasit Vectors · 2026 Jul · PMID 42399999 · Full text
In the field of global health, mosquito-borne infectious diseases (such as malaria, dengue fever, and Zika) remain serious public health concerns. Recent research has emphasized that mosquitoes must coordinate their repr...
In the field of global health, mosquito-borne infectious diseases (such as malaria, dengue fever, and Zika) remain serious public health concerns. Recent research has emphasized that mosquitoes must coordinate their reproductive output and immune defenses under limited energy and nutritional conditions, forming a tightly regulated trade-off. This process involves complex signaling pathways and stage-specific molecular mechanisms. Key factors, such as juvenile hormone (JH), 20-hydroxyecdysone (20E), autophagy pathways, immune-regulatory genes, and metal ions, can potentially influence this equilibrium state, thereby either promoting or inhibiting the occurrence and development of mosquito-borne infectious diseases. However, the exact mechanism underlying this regulation remains unclear. This review summarizes recent findings on how these components interact at the molecular and physiological levels, with the aim of developing a rational framework for identifying potential molecular targets and developing new strategies for vector control.
A novel activation-related gene P158 is essential for evagination and early development of Echinococcus multilocularis protoscoleces.
Xin Z, Wang Z, Fu Y … +12 more , Jin C, Zhou X, Wu Y, Zhi W, Chu M, Zheng L, Zhang A, Qian C, Nonaka N, Nakao R, Guo Z, Liu G
Parasit Vectors · 2026 Jul · PMID 42393807 · Full text
BACKGROUND: Alveolar echinococcosis is a lethal zoonotic parasitic disease caused by Echinococcus multilocularis. The activation and subsequent evagination of protoscoleces (PSCs) in the host digestive tract are critical...
BACKGROUND: Alveolar echinococcosis is a lethal zoonotic parasitic disease caused by Echinococcus multilocularis. The activation and subsequent evagination of protoscoleces (PSCs) in the host digestive tract are critical steps for establishing infection in definitive hosts, yet the underlying molecular mechanisms remain poorly understood. METHODS: In this study, we employed an in vitro PSC activation model combined with transcriptomic analysis to identify activation-associated genes. A novel gene, designated P158, was further characterized by transcriptional unit analysis and functional knockdown assays to assess its role in PSC evagination, viability, tegument integrity, energy metabolism, and early metacestode development. RESULTS: We confirmed that P158 constitutes an independent transcriptional unit from the adjacent DDX1 gene of E. multilocularis and found that P158 expression was significantly upregulated following activation. Knockdown of P158 led to a significant reduction in PSC evagination rate and impaired metacestode vesicular development in vitro. Concurrently, decreased cellular viability and damage to the microtriches indicated compromised tegument structural integrity. Further mechanistic analysis showed that P158 knockdown triggered metabolic dysregulation, characterized by reduced ATP levels, shrinkage of glycogen storage cells, and depletion of intracellular glycogen reserves. CONCLUSIONS: These findings demonstrate that P158 plays an essential role in promoting PSC evagination and early development by maintaining tegument structural integrity and regulating energy metabolism homeostasis. This study highlights P158 as a potential target for interventions aimed at blocking parasite development at the definitive host stage.
Seroprevalence of Dirofilaria immitis in traveling dogs: implications for transboundary pathogen movement.
Quintana TA, Aguinaga B, Mitchell J … +3 more , Schieferecke G, Seetahal JFR, Jesudoss Chelladurai JRJ
Parasit Vectors · 2026 Jul · PMID 42393794 · Full text
BACKGROUND: Dirofilaria spp. are parasitic filarial nematodes endemic worldwide that infect dogs but are also zoonotic. Traveling dogs may serve as carriers of zoonotic parasites, including Dirofilaria immitis, introduci...
BACKGROUND: Dirofilaria spp. are parasitic filarial nematodes endemic worldwide that infect dogs but are also zoonotic. Traveling dogs may serve as carriers of zoonotic parasites, including Dirofilaria immitis, introducing them to new regions. However, the risks of importation from endemic areas are unknown. METHODS: To study seroprevalence in travelling dogs, we first established the signal-to-positive (S/P) cutoffs for the DiroCHEK ELISA assay (Zoetis) by spectrophotometry at three wavelengths (490, 620, or 650 nm). We also validated the assay for testing serum pools using known D. immitis-positive serum. We tested sera collected from 6699 dogs traveling from 34 countries between September 2022 and December 2023 using the spectrophotometric method. Samples were tested in serum pools initially, with pool sizes ranging from 5 to 15 samples based on reported prevalence. All pools were tested with and without heat treatment to disassociate immune complexes. Where sample numbers were insufficient to form a pool, samples were tested individually without heat treatment. Dogs in pools that tested positive were retested individually without heat treatment. Prevalence was calculated from pooled testing and individual testing results. RESULTS: We tested 649 serum pools, of which 50 heat-treated pools and 11 non-heat-treated pools tested positive spectrophotometrically. Of these 61 positive pools, 7 tested positive in non-heat treated and heat-treated conditions, resulting in 54 unique pools. During re-testing of individual dogs from the positive pools, 31 pools contained dogs infected with D. immitis, while 23 pools had no positive individuals identified, indicating the presence of cross-reactive nematodes or antigen-antibody complexes. The prevalence of D. immitis and cross-reactive nematodes based on pooled testing was 0-5.32%. Due to the unavailability of specific serological tests for cross-reactive nematodes, they were not identified further. The prevalence of D. immitis based on individual testing was 0-11.1%, which was lower than the reported prevalence in their countries of origin. CONCLUSIONS: Our findings indicate that traveling dogs may carry D. immitis and cross-reactive nematodes, increasing the risk of introducing these parasites and/or novel parasite genetics to new areas. While pooled testing allows for screening populations rapidly, this methodology may underestimate true prevalence, particularly in low-prevalence regions.
A comprehensive proteome and the first phosphoproteome reveal extensive phosphorylation of carbohydrate metabolism in Cryptosporidium parvum sporozoites.
Wang D, Li M, Wang C … +3 more , Li H, Yin J, Zhu G
Parasit Vectors · 2026 Jul · PMID 42393791 · Full text
BACKGROUND: Cryptosporidium parvum is an obligate apicomplexan parasite and a major cause of diarrheal disease in humans and animals worldwide. Despite its public health importance, the molecular regulation of parasite m...
BACKGROUND: Cryptosporidium parvum is an obligate apicomplexan parasite and a major cause of diarrheal disease in humans and animals worldwide. Despite its public health importance, the molecular regulation of parasite metabolism, particularly at the post-translational level, remains poorly understood. This study aims to understand major pathways regulated by protein phosphorylation in sporozoites, the parasite invasive stage, by comparative analysis of the proteomic and phosphoproteomic profiles. METHODS: The proteome and phosphoproteome of excysted sporozoites of C. parvum were determined by data-independent acquisition-based mass spectrometry. Highly abundant pathways at proteomic and phosphoproteomic levels were identified by functional enrichment. A relative phosphorylation index (RPI) was developed for comparative assessment of phosphorylation propensity across proteins. RESULTS: Proteomics identified 2,272 proteins in the sporozoites, representing 58% of the predicted parasite proteome. Phosphoproteomics identified 8,994 phosphorylation sites across 2,141 proteins; after intensity filtering, 833 phosphoproteins were retained for downstream analysis, representing 36.7% of the detected proteome. The correlations between transcript and protein abundances are weak. Proteins involved in carbohydrate metabolism, particularly glycolysis, are highly abundant in the proteome and phosphoproteome. Proteins in carbohydrate metabolism, signaling, cytoskeletal organization, and host-parasite interaction are selectively phosphorylated. In carbohydrate metabolism, starch degradative enzymes exhibit greater phosphorylation propensity than glycolytic and fermentative enzymes. CONCLUSIONS: The C. parvum sporozoites translate more than half of the protein-coding genes, in which one-third of the proteome is phosphorylated in varied degrees. In the highly active energy metabolism, starch degradation enzymes show greater phosphorylation propensity than core glycolytic and fermentative enzymes. This study reveals the first phosphoproteome and the largest proteome for C. parvum, providing a resource for further investigations of the functional regulation by protein phosphorylation.
Molecular characterization of Blastocystis sp., Cryptosporidium spp., and Giardia spp. in Eld's deer (Rucervus eldii) and their forest rangers in Hainan, China.
Zhang Y, Li J, Xie Z … +15 more , Han X, Du W, Qiang Y, Ren G, Lei S, Chang Y, Liu X, Lai X, Wang Y, Li X, Zhou Y, Han W, Qi X, Wang H, Lu G
Parasit Vectors · 2026 Jul · PMID 42393789 · Full text
BACKGROUND: Blastocystis sp., Cryptosporidium spp., and Giardia spp. are significant zoonotic enteric protozoans colonizing/parasitizing humans and animals worldwide. Eld's deer (Rucervus eldii) is a globally endangered...
BACKGROUND: Blastocystis sp., Cryptosporidium spp., and Giardia spp. are significant zoonotic enteric protozoans colonizing/parasitizing humans and animals worldwide. Eld's deer (Rucervus eldii) is a globally endangered tropical deer species. Prevalence and genetic diversity of these pathogens in wild Eld's deer and occupationally exposed human populations remain limited. This study investigated the occurrence, molecular characteristics, and zoonotic potential of these three protozoans in wild Eld's deer and their forest rangers in Hainan, China. METHODS: A total of 217 fresh fecal samples were collected from wild Eld's deer across two isolated habitats, and 19 stool samples were obtained from forest rangers, within the Hainan Bangxi Provincial Nature Reserve from March to August 2021. Genomic DNA was extracted and examined by polymerase chain reaction (PCR) targeting the SSU rRNA region for Blastocystis sp., and by nested PCR targeting the SSU rRNA region for Cryptosporidium spp., and the bg and gdh region for Giardia spp. The subtypes, species, and genotypes of positive amplicons were determined through sequence homology analysis and phylogenetic reconstruction using the neighbor-joining method. RESULTS: The overall prevalence of Blastocystis sp., Cryptosporidium spp., and Giardia spp. in wild Eld's deer were 25.8% (56/217), 5.5% (12/217), and 2.8% (6/217), respectively. Co-infections were detected in 3.2% (7/217) of deer samples. In Eld's deer, six Blastocystis subtypes were identified (ST10, ST21, ST23, ST24, ST25, ST26), with ST10 being predominant (57.1%). Five Cryptosporidium species/genotypes were characterized (Cryptosporidium bovis, Cryptosporidium xiaoi, Cryptosporidium sp. bamboo rat genotype I, Cryptosporidium sp. bamboo rat genotype III, and Cryptosporidium sp. hamster genotype), with C. bovis being predominant (50.0%). All Giardia spp.-positive samples were identified as Giardia bovis (previously known as assemblage E). In the forest rangers, one Blastocystis ST3, two C. xiaoi, and one Cryptosporidium sp. hamster genotype were detected. Notably, the isolates of Cryptosporidium sp. hamster genotype in human and wild Eld's deer showed 100% homology based on SSU ribosomal RNA (rRNA) gene sequencing analysis. Three novel sequences within Blastocystis subtypes (ST10 and ST26), three novel Cryptosporidium sequences (Cryptosporidium sp. bamboo rat genotype I, Cryptosporidium sp. bamboo rat genotype III, and Cryptosporidium sp. hamster genotype), and five novel G. bovis sequences (based on bg and gdh genes) were identified. CONCLUSIONS: This first molecular survey reveals high genetic diversity of Blastocystis sp., Cryptosporidium spp., and Giardia spp. in wild Eld's deer in China, including the detection of shared Cryptosporidium species/genotypes between this endangered deer and sympatric forest rangers. These findings suggest potential zoonotic transmission at the wildlife-human interface and underscore the need for an integrated One Health surveillance strategy in protected areas to mitigate cross-species transmission risks, thereby contributing to both wildlife conservation and public health protection.
Droplet digital PCR-based pathogen monitoring system improves identifying Haemaphysalis longicornis infected with Bandavirus dabieense and other tick-borne pathogens at low concentrations.
Baek Y, Jeong JH, Jeong DE … +3 more , Kang JG, Shin Y, Kim IH
Parasit Vectors · 2026 Jul · PMID 42387608 · Full text
BACKGROUND: Asian long-horned ticks, Haemaphysalis longicornis, vector viruses, bacteria and parasites that cause major zoonotic diseases in human. In order to prevent and manage the spread of tick-borne zoonosis, it is...
BACKGROUND: Asian long-horned ticks, Haemaphysalis longicornis, vector viruses, bacteria and parasites that cause major zoonotic diseases in human. In order to prevent and manage the spread of tick-borne zoonosis, it is important to monitor pathogen prevalence in wild tick populations using molecular diagnostics with high detection performance. In this study, we introduce a novel droplet digital PCR (ddPCR)-based pathogen monitoring system to identify Haemaphysalis longicornis ticks infected with Bandavirus dabieense and other zoonotic pathogens at low concentrations with higher sensitivity and accuracy from existing molecular detection methods. METHODS: Using metrologically certified B. dabieense RNA reference materials, we directly compared the detection limits between ddPCR and quantitative PCR (qPCR). Then, among 502 individual H. longicornis adult ticks collected from fields, we determined the detection rate of ticks infected with B. dabieense. We also investigated tick innate immune system, JAK/STAT, for its relevance in identifying ticks infected with low concentrations of B. dabieense. From B. dabieense-infected ticks, we examined for other tick-borne pathogens and nucleic acid concentrations of identified pathogens using ddPCR. RESULTS: Our ddPCR-based method showed high sensitivity by 20 times lower detection limits than that of qPCR. Detection rate of ticks infected with B. dabieense from fields was 35.9%. Among ticks infected with low B. dabieense virus concentrations, defined by the B. dabieense RNA copy numbers in bottom 25% quartiles observed from infected ticks, STAT expression level was significantly higher compared to laboratory strains and uninfected field populations. Lastly, multiplexed ddPCR results indicated that individual ticks can harbor up to four different pathogens concurrently. CONCLUSIONS: Our newly developed ddPCR-based pathogen monitoring system improves the identification of H. longicornis infected with B. dabieense and other tick-borne pathogens at low nucleic acid concentrations compared with qPCR. In addition, our results suggest that STAT expression may provide exploratory and complementary insight into tick innate immune activation in low-copy B. dabieense infections, and that ddPCR-based multiplexing can detect co-infections with multiple tick-borne pathogens in individual ticks. These findings highlight the potential of ddPCR as a sensitive and practical tool for surveillance and management of tick-borne zoonotic pathogens in vector populations.
Field evaluation of a novaluron-based larvicide tablet (MOSQINOk 0.8P) in irrigated rice agroecosystems of The Gambia: a controlled quasi-experimental study.
Jawara EA, Nyassi MT, Sanneh S … +6 more , Samateh W, Gibba B, Gomez SS, Soumare HM, Ali AI, Al-Zaidi S
Parasit Vectors · 2026 Jul · PMID 42387578 · Full text
BACKGROUND: Larval source management remains a potentially important supplementary strategy for malaria vector control, particularly in irrigated agroecosystems, where mosquito breeding habitats are relatively stable and...
BACKGROUND: Larval source management remains a potentially important supplementary strategy for malaria vector control, particularly in irrigated agroecosystems, where mosquito breeding habitats are relatively stable and predictable. This study evaluated the operational effectiveness of a novaluron-based larvicide tablet (MOSQINOk 0.8P) for reducing mosquito larval and adult densities in irrigated rice-growing communities in The Gambia. METHODS: A quasi-experimental controlled field study was conducted between September and December 2025 in two irrigated rice-growing communities in the Central River Region of The Gambia. Janjangbureh was assigned as the intervention site and Sankuli Kunda as the untreated control. Larval habitats were monitored weekly, while adult mosquitoes were collected biweekly using CDC light traps. Difference-in-differences analyses using negative binomial generalized estimating equation models were used to estimate intervention effects. RESULTS: MOSQINOk application was associated with a significant reduction in total larval density per dip (IRR = 0.459, 95% CI 0.216-0.974; p = 0.042), corresponding to an estimated 54.1% reduction relative to the control site. Late instar larval densities also declined in the intervention arm (IRR = 0.485, 95% CI 0.186-1.260), although this was not statistically significant. Pupae were nearly absent in treated habitats following larvicide application. Adult Anopheles densities also declined in the intervention arm, with difference-in-differences models showing reductions in overall adult Anopheles (IRR = 0.385, 95% CI 0.121-1.225), Anopheles gambiae s.l. (IRR = 0.316, 95% CI 0.098-1.014), and Anopheles funestus (IRR = 0.443, 95% CI 0.107-1.834). CONCLUSIONS: These findings provide preliminary evidence that MOSQINOk 0.8P can contribute to suppression of mosquito larval populations and may reduce adult vector densities in irrigated rice agroecosystems. Larger and longer-term studies are warranted to confirm effectiveness and scalability.
Integrative morphological and DNA barcoding analysis of Forcipomyia (Lasiohelea) midges: cryptic diversity and first molecular detection of multiple Leishmania species in a leishmaniasis-endemic focus in Southern Thailand.
Nadeem M, Sunantaraporn S, Promrangsee C … +7 more , Sricharoensuk C, Ampol R, Boonserm R, Somwang P, Khositharattanakool P, Siriyasatien P, Preativatanyou K
Parasit Vectors · 2026 Jun · PMID 42381029 · Full text
BACKGROUND: Ceratopogonid midges of the genus Forcipomyia (subgenus Lasiohelea) are small hematophagous insects widely distributed across tropical regions. In Australia, developmental stages of Leishmania (Mundinia) macr...
BACKGROUND: Ceratopogonid midges of the genus Forcipomyia (subgenus Lasiohelea) are small hematophagous insects widely distributed across tropical regions. In Australia, developmental stages of Leishmania (Mundinia) macropodum have been observed in Forcipomyia (Lasiohelea), suggesting that biting midges may play a role in Leishmania transmission beyond traditional sand fly vectors. However, in Southeast Asia-where leishmaniasis caused by Mundinia species is an emerging autochthonous disease in humans-fundamental information on Forcipomyia (Lasiohelea) diversity and its association with Leishmania remains limited. METHODS: An integrated morphological-molecular approach was employed to characterize Forcipomyia (Lasiohelea) midges collected using sweep nets from a leishmaniasis-endemic area in Nakhon Si Thammarat Province, Southern Thailand, near the residence of a patient with locally acquired cutaneous leishmaniasis, during January and June 2025. Morphological examination of mandibular dentition, sensory pits, cibarial armature, and spermathecal structure was combined with mitochondrial cox1 barcoding, Bayesian and maximum likelihood phylogenetic analyses, and species delimitation methods (ASAP and mPTP). Because females of the subgenus Lasiohelea possess a single spermatheca, only single-spermatheca females were selected for species identification. Specimens identified as Lasiohelea were subsequently screened for Leishmania using 18S rRNA-qPCR and ITS1-PCR, followed by nanopore-based ITS1 metabarcoding for species-level identification. Vertebrate blood meal sources were also characterized using vertebrate cox1 metabarcoding. RESULTS: From 264 collected midges, 72 female specimens with a single spermatheca were selected for analysis. Integrated morphological and molecular data identified seven Lasiohelea specimens forming four genetic clusters, comprising F. (L.) parvitas (n = 2) and three lineages closely related to F. (L.) peditata (n = 2), F. (L.) humilavolita (n = 2), and F. (L.) taiwana (n = 1). These were clearly separated from non-Lasiohelea taxa, including F. (Euprojoannisia) fuscimana and two unclassified Ceratopogonidae lineages. Phylogenetic and species delimitation analyses revealed cryptic genetic diversity despite morphological similarity. Leishmania DNA was detected in six of seven Lasiohelea specimens. Nanopore ITS1 metabarcoding identified autochthonous species (L. (Mundinia) martiniquensis and L. (M.) orientalis) and additional Leishmania species (L. (Leishmania) amazonensis and L. (L.) major), including mixed-species detections in four specimens. A single engorged specimen contained DNA from red junglefowl (Gallus gallus spadiceus). CONCLUSIONS: This study provides the first integrated characterization of Forcipomyia (Lasiohelea) diversity and associated Leishmania detection in Southeast Asia. The results identified several putatively distinct species within Lasiohelea and provide evidence of natural exposure of these midges to multiple Leishmania species, suggesting a complex parasite-midge association and parasite co-circulation in the local environment. Although vector competence was not assessed, these findings suggest that Forcipomyia (Lasiohelea) may be involved in the circulation of Leishmania parasites and may represent promising candidates for further investigation of vector competence. Future studies focusing on host associations, parasite development, and experimental transmission are needed to clarify their epidemiological significance.
Geographic variability of severe fever with thrombocytopenia syndrome virus genomes in the Miyazaki Prefecture, Japan: a cross-sectional molecular epidemiological study.
Narita T, Yano K, Miura M … +8 more , Nomachi T, Shinden M, Tsuru N, Onitsuka S, Yoshino S, Yamamoto S, Ando S, Okabayashi T
Parasit Vectors · 2026 Jun · PMID 42380936 · Full text
BACKGROUND: Severe fever with thrombocytopenia syndrome (SFTS) is a tick-borne disease caused by the SFTS virus (SFTSV). In Japan, the highest number of SFTS cases has been reported in the Miyazaki Prefecture. Despite pr...
BACKGROUND: Severe fever with thrombocytopenia syndrome (SFTS) is a tick-borne disease caused by the SFTS virus (SFTSV). In Japan, the highest number of SFTS cases has been reported in the Miyazaki Prefecture. Despite previous genomic studies, the regional genomic diversity of SFTSV in Japan remains poorly characterized at the prefectural level. Hence, we aimed to analyze the whole genome sequencing of SFTSV strains collected in the Miyazaki Prefecture to assess their genomic diversity. METHODS: Epidemiological data from patients were analyzed, and amplicon-based whole genome sequencing of SFTSV was performed using serum or plasma samples collected between 2012 and 2023 in the Prefecture. The resulting sequences were used to construct a phylogenetic tree, and the distribution of SFTSV genotypes was analyzed according to the presumed regions of infection. RESULTS: The phylogenetic analysis revealed that four genotypes of SFTSV were present in the Prefecture, including currently unclassifiable genotypes and a novel subgenotype named J4. Analysis of the geographic distribution of each genotype revealed an association between genotypes and presumed regions of infection. Notably, potential genetic reassortment and recombination events were confirmed in Japanese strains. CONCLUSIONS: This study provides the largest whole genome sequencing of SFTSV conducted in Japan to date and confirms that SFTSV genotypes in the Miyazaki Prefecture exhibits strong regionality. Accordingly, we hypothesized that the dispersion of SFTSV through ticks and wild animals may be relatively limited. SFTSV genome analysis may help to estimate infection locations, particularly for cases with an unclear exposure history.
Optimisation and analytical assessment of a TaqMan™ probe-based real-time PCR assay designed to diagnose infection with Schistosoma japonicum.
Archer J, Hingel S, Abarsosa C … +3 more , Zabala K, Nailes JM, Webster BL
Parasit Vectors · 2026 Jun · PMID 42374591 · Full text
BACKGROUND: Intestinal schistosomiasis, caused by infection with Schistosoma japonicum, remains a zoonotic neglected tropical disease (NTD) of significant public health importance in parts of China, the Philippines, and...
BACKGROUND: Intestinal schistosomiasis, caused by infection with Schistosoma japonicum, remains a zoonotic neglected tropical disease (NTD) of significant public health importance in parts of China, the Philippines, and Indonesia. Ongoing schistosomiasis control programmes in these areas have achieved significant reductions in disease prevalence, transmission, and morbidity associated with infection; however, they have also presented new challenges, particularly in detecting and monitoring low-intensity and low-prevalence S. japonicum infections. Highly sensitive and highly specific diagnostic assays are therefore needed for effective disease diagnosis and transmission monitoring in low-endemicity areas, and the development of such assays has been recommended by the World Health Organisation. METHODS: We first aimed to determine whether a Schistosoma spp. genus-specific real-time PCR assay routinely used to diagnose infections with African schistosome species (namely Schistosoma mansoni and Schistosoma haematobium), as well as two more recently developed S. japonicum species-specific real-time PCR assays, can accurately diagnose low-intensity S. japonicum infections. We also sought to optimise one of the S. japonicum species-specific real-time PCR assays by adding the same DNA extraction and PCR internal positive control target commonly used with the Schistosoma spp. genus-specific real-time PCR assay. This was done using in silico analyses and endpoint PCR with Sanger sequencing and real-time PCR using genomic DNA isolated from Schistosoma spp. adult worms, HO spiked with individual S. japonicum ova, and naïve human faecal material also spiked with individual S. japonicum ova. RESULTS: We demonstrate that the Schistosoma spp. genus-specific real-time PCR assay and one of the S. japonicum species-specific real-time PCR assays described here are likely incapable of reliably diagnosing low-intensity S. japonicum infections. We also demonstrate that the other S. japonicum species-specific real-time PCR assay can be performed using an additional DNA extraction and PCR internal positive control target and may reliably diagnose low-intensity S. japonicum infections. CONCLUSIONS: Whilst clinical assessment of the optimised S. japonicum species-specific real-time PCR assay described here is needed, it is our hope that this assay will become a standard and routinely used method to diagnose low-intensity S. japonicum infections and will be used support future S. japonicum transmission surveillance and elimination programmes.
Emergence and spatial distribution of knockdown resistance in a suburban population of Aedes albopictus.
Baltzegar JF, Butler CD, Ding JY … +4 more , Beeson CM, Reed EMX, Reiskind MH, Burford Reiskind MO
Parasit Vectors · 2026 Jun · PMID 42365369 · Full text
BACKGROUND: Aedes albopictus is a major vector of arboviral diseases and is often targeted by pyrethroid-based mosquito control in residential areas. While knockdown resistance (kdr) mutations are well-documented in Ae....
BACKGROUND: Aedes albopictus is a major vector of arboviral diseases and is often targeted by pyrethroid-based mosquito control in residential areas. While knockdown resistance (kdr) mutations are well-documented in Ae. aegypti, their emergence in Ae. albopictus has been less studied, particularly in suburban environments, where insecticide application is often uncoordinated. Understanding the temporal and spatial dynamics of resistance evolution in this context is critical for preserving the effectiveness of public health interventions. METHODS: We conducted longitudinal sampling of Ae. albopictus populations in Wake County, North Carolina, from 2016 to 2024. Using a novel allele-specific PCR melt curve assay, we genotyped 2,669 mosquitoes at the F1534S locus in the voltage-gated sodium channel gene. Resistance allele frequencies were calculated annually and mapped across the county for three key years, representing the pre-emergence (2016), initial detection (2018), and widespread phases of resistance development (2023). Selection and dominance were estimated using the Wright-Fisher approximate Bayesian computation algorithm for locus F1534S. RESULTS: The F1534S resistance allele was first detected in 2018 at a central neighborhood in Wake County. By 2023, the allele had become distributed throughout the sampling region, with the highest observed frequencies near the site of first detection. Resistance allele frequency peaked at 0.36 in 2023, accompanied by an increase in heterozygous and homozygous resistance genotypes. Temporally sampled sites showed consistent trends in rising frequencies of the resistance allele, with all temporally sampled locations harboring resistance genotypes by 2022. The resistance allele was estimated to have a high selection coefficient and to be partially recessive in this population. CONCLUSIONS: Our findings reveal rapid emergence and spatial distribution of the F1534S kdr allele in a suburban population of Ae. albopictus. The observed distribution of resistance alleles is consistent with strong genetic selection. These results highlight the need for proactive resistance monitoring and integrated management strategies that address private-sector contributions to insecticide selection pressure.
Divergent responses to urbanisation and forest cover shape the spatial distribution of Culex pipiens ecotypes in western Switzerland.
Perrin A, Deillon C, Christe P … +1 more , Glaizot O
Parasit Vectors · 2026 Jun · PMID 42363267 · Full text
BACKGROUND: Arthropod-borne viruses are increasingly reported across Europe, with Culex pipiens serving as the main vector of West Nile and Usutu viruses. The C. pipiens complex comprises two ecologically distinct ecotyp...
BACKGROUND: Arthropod-borne viruses are increasingly reported across Europe, with Culex pipiens serving as the main vector of West Nile and Usutu viruses. The C. pipiens complex comprises two ecologically distinct ecotypes, pipiens and molestus, which can hybridise. These ecotypes are thought to differ in habitat preference, with C. p. molestus more frequent in urban environments and C. p. pipiens in natural ones. However, many studies have either not distinguished between these ecotypes or have investigated them without considering a clear landscape gradient. This information is nevertheless important for understanding vector distribution and the potential implications for virus transmission pathways and spillover risk. METHODS: A season-long survey was conducted from May to September 2025 across 57 sampling sites in Switzerland. Mosquitoes were morphologically identified, and C. pipiens ecotypes were distinguished using molecular analyses. We characterised landscape composition and their scale of effects, as well as meteorological conditions on the sampling dates to determine their influence on the presence and relative proportion of each C. pipiens ecotype. RESULTS: Agricultural landscapes promoted all ecotypes, urbanisation positively influenced C. p. pipiens but not C. p. molestus, and forest cover reduced the presence and relative proportion of hybrids. In addition, temperature was positively correlated with all ecotype presence, whereas rainfall had no detectable effect. CONCLUSIONS: The responses to landscape variables differ among C. pipiens ecotypes and across different landscape features. This highlights the complex, context-dependent interactions between the ecology of mosquitoes and the composition of their habitat, which ultimately determine their spatial distribution patterns.
Portable experimental hut tents (PEHTs): a conceptual framework for improved malaria vector control decision-making with a review of fixed experimental hut sites in Africa.
Oxborough RM, Wickramasinghe T, Gopakumar N … +11 more , Fong M, Sabtiu ARM, Qualls WA, Diclaro JW, Stamey J, Xue RD, Tiruha Y, Churcher TS, Park S, Afrane Y, Messenger LA
Parasit Vectors · 2026 Jun · PMID 42363266 · Full text
BACKGROUND: Insecticide-treated nets (ITNs) remain the primary vector control method across sub-Saharan Africa to prevent malaria transmission, with 2.2 billion pyrethroid (PY) ITNs distributed since 2004. Widespread PY...
BACKGROUND: Insecticide-treated nets (ITNs) remain the primary vector control method across sub-Saharan Africa to prevent malaria transmission, with 2.2 billion pyrethroid (PY) ITNs distributed since 2004. Widespread PY resistance has contributed to stalling progress in recent years; however, new ITNs containing the pyrrole, chlorfenapyr, or the synergist piperonyl butoxide can provide improved efficacy. With more vector control options but limited resources, malaria programs face complex decisions influenced by local transmission intensity, mosquito species, and dynamic insecticide resistance patterns. Decisions are often based on subnational bioassay data, which are not indicative of ITN field performance of newer non-neurotoxic insecticides. METHODS: The gold-standard entomological method for assessing ITN performance is experimental hut trials; however, hut sites are fixed in place and often not representative of high-malaria-burden contexts. This manuscript consists of two components: the first is a literature review of fixed experimental hut sites in Africa. The second describes a new conceptual framework and design of portable experimental hut tents (PEHTs). RESULTS: The literature review identified 34 experimental hut sites in malaria-endemic Africa. The West-African style hut was the most widely adopted design, used in 24 sites, with most (19/34) located near rice fields for consistent vector yield. The novel PEHT design is based on West African-style huts, using large cabin-style tents equipped with a veranda and 3D-printed lightweight mosquito entry points. A major advantage of PEHTs is their portability for use within high-malaria-burden villages to evaluate community-used ITNs of varying ages against local malaria vector populations, which can support data-driven subnational vector control tailoring. Beyond the evaluation of ITNs, PEHTs can be utilized for studies of new vector control technologies, such as spatial repellent emanators, and can generate evidence for improved vector control practices during humanitarian emergencies, military deployments, and in settings with emerging vector-borne disease threats. CONCLUSIONS: This study describes the innovative concept and design of PEHTs for expanded evaluation of vector control tools in a wider geographical range against local, heterogeneous mosquito populations.
Serological and molecular positivity for Leishmania infantum in dogs referred to two veterinary hospitals in Barcelona, Spain.
Corominas P, Fernández M, Viñeta C … +4 more , Blasi-Brugué C, Pol G, Francino O, Roura X
Parasit Vectors · 2026 Jun · PMID 42363239 · Full text
BACKGROUND: Leishmania infantum is endemic in the Mediterranean basin, with dogs serving as the primary domestic reservoir for human infection. Although the city of Barcelona has historically been considered a low-risk a...
BACKGROUND: Leishmania infantum is endemic in the Mediterranean basin, with dogs serving as the primary domestic reservoir for human infection. Although the city of Barcelona has historically been considered a low-risk area, recent environmental and demographic changes may favor parasite transmission. This study aimed to estimate and compare the positivity to L. infantum using serological and molecular methods in dogs referred to a veterinary hospital in the city of Barcelona (urban) and to another located in its residential metropolitan area (peri- urban), and to assess potential associated risk factors. METHODS: A cross-sectional study was conducted from September 2022 to September 2023 at two veterinary referral hospitals in the urban (hospital A) and peri-urban (hospital B) areas of Barcelona. Blood and conjunctival swab samples were analyzed by quantitative ELISA and qPCR targeting L. infantum kinetoplast DNA. RESULTS: A total of 189 client-owned dogs were enrolled (77 from hospital A and 112 from hospital B). Of these, 93/189 (49.2%) were presented for an annual check-up and appeared healthy, while 96/189 (50.8%) were sick. Leishmania infantum infection-defined as positivity by ELISA and/or qPCR-was detected in 10.6% (20/189) dogs, exclusively among sick patients (20/96;20.8%). None of the healthy dogs tested positive. Both serological and molecular tests yielded a 6.3% (12/189) positivity. All qPCR-positive dogs belonged to hospital B, resulting in a higher positivity rate among dogs referred to the peri-urban hospital (15.2%) than among those referred to the urban hospital (3.9%). Significant associations were identified between positivity and both clinical status (P < 0.001) and hospital location (P = 0.013), but not with the other variables evaluated. CONCLUSION: The findings confirm active L. infantum transmission among dogs in Barcelona, with higher positivity among dogs referred to a hospital in the peri-urban area.
Influence of Cryptosporidium parvum and Giardia duodenalis on glucose transport mechanisms and tight junctions in co-infected enterocytes.
Delling C, Kirchner M, May K … +1 more , Dengler F
Parasit Vectors · 2026 Jun · PMID 42351155 · Full text
BACKGROUND: Cryptosporidium parvum and Giardia duodenalis (assemblages A and B) are ubiquitously occurring protozoan parasites infecting a broad range of hosts. Co-infection with both parasites in suitable hosts have bee...
BACKGROUND: Cryptosporidium parvum and Giardia duodenalis (assemblages A and B) are ubiquitously occurring protozoan parasites infecting a broad range of hosts. Co-infection with both parasites in suitable hosts have been reported, but information on structural or functional alterations in host cells caused by simultaneous infection is rare. Previous findings showing an enhanced replication of G. duodenalis during co-infection suggest synergistic effects of both parasites that were investigated in this in vitro study. METHODS: The tight junction proteins claudin (CLDN) 1, 4, 6, and 7 as well as the glucose transporters (GLUT) 1 and 2 of IPEC-J-2 cells were examined comparing single and co-infections on gene expression level after 24 h, 48 h, and 72 h post infection (p.i.). Additionally, an analysis of intracellular glucose levels was performed 48 h p.i. RESULTS: No significant changes of the gene expression of the examined tight junction proteins were observed. Regarding the glucose transporters, GLUT2 was significantly decreased in cells infected by C. parvum sporozoites compared to cells infected by G. duodenalis trophozoites 48 h p.i. (p = 0.017) as well as compared to uninfected control cells (p = 0.021). Additionally, co-infected cells showed a significantly increased intracellular glucose level (p = 0.022) and C. parvum infected cells a non-significant trend of an increased intracellular glucose level (p = 0.056) in comparison to control cells. Compared to G. duodenalis mono-infected cells, co-infected cells showed a tendency for higher intracellular glucose levels (p = 0.057). CONCLUSION: Cryptosporidium parvum had an impact on GLUT2 transcript abundance and also increased glucose levels in mono- and co-infection under the tested conditions, while G. duodenalis did not alter the examined glucose transporter and tight junctions markers in this model.
Cyclin-dependent kinase-inhibitor screening and structural analysis identify a CDK-like kinase candidate in Naegleria fowleri.
Kim MJ, No JH
Parasit Vectors · 2026 Jun · PMID 42343468 · Full text
BACKGROUND: Primary amebic meningoencephalitis (PAM) caused by Naegleria fowleri is a highly fatal central nervous system infection for which effective treatment options remain limited. This study explored CDK-related pa...
BACKGROUND: Primary amebic meningoencephalitis (PAM) caused by Naegleria fowleri is a highly fatal central nervous system infection for which effective treatment options remain limited. This study explored CDK-related pathways in N. fowleri using a focused CDK inhibitor library and structure-based analysis of a selected CDK-like protein. METHODS: A library of 126 CDK inhibitors was screened against N. fowleri trophozoites using a luminescence-based ATP viability assay, and active compounds were further evaluated in dose-response assays. Human CDK1-9 sequences were used for BLASTp searches against the N. fowleri proteome, followed by comparative sequence analysis with Trypanosoma brucei cdc2-related kinases (CRKs). Nf_CDK-like protein1 (FDP41_013684) was selected for homology modeling, molecular docking, and 100-ns molecular dynamics simulations. RESULTS: Screening identified 23 active CDK inhibitors with IC values ≤ 10 μM against N. fowleri, including five prioritized compounds with submicromolar activity: AZD5438, GSK-3 inhibitor IX, milciclib, roniciclib, and SU9516 (IC, 0.30-0.88 μM). Sequence analysis identified five CDK-like proteins in the N. fowleri proteome, among which Nf_CDK-like protein1 showed the highest similarity to T. brucei CRK3 and shared approximately 58-61% sequence identity with human CDK1/2. Conserved kinase features, including the glycine-rich loop, αC-helix, hinge region, DFG motif, and activation loop, were retained in Nf_CDK-like protein1. Docking analysis placed all five prioritized compounds within the predicted ATP-binding cleft, with shared interactions around Lys60, Tyr42, Asp113, and the hinge-proximal residues Ile110 and Asp111. Molecular dynamics simulations showed generally stable protein backbones and ligand poses over 100 ns. CONCLUSIONS: This study identified multiple CDK inhibitor scaffolds with potent in vitro activity against N. fowleri and supports Nf_CDK-like protein1 as a plausible CDK-like kinase target candidate through integrated phenotypic and structure-based analyses, with direct biochemical validation needed in future studies. These findings suggest that CDK-like pathways may represent a relevant molecular axis in N. fowleri and provide a basis for future structure-guided optimization of anti-amoebic candidates.
Comparative proteomics reveals distinct functions and localization of invasive Entamoeba histolytica and non-invasive Entamoeba moshkovskii proteins.
Leetachewa S, Khomkhum N, Roytrakul S … +3 more , Reamtong O, Chavalitshewinkoon-Petmitr P, Moonsom S
Parasit Vectors · 2026 Jun · PMID 42343385 · Full text
BACKGROUND: Entamoeba histolytica is a pathogenic protozoan accountable for amoebiasis, while Entamoeba moshkovskii is considered non-invasive. Despite morphological similarity, the molecular mechanisms underlying their...
BACKGROUND: Entamoeba histolytica is a pathogenic protozoan accountable for amoebiasis, while Entamoeba moshkovskii is considered non-invasive. Despite morphological similarity, the molecular mechanisms underlying their different pathogenicity remain largely undefined. METHODS: Trophozoite proteins from axenic cultures of E. histolytica and E. moshkovskii were separated and identified using GeLC-MS/MS, and classified using Gene Ontology. Selected and differentially expressed proteins were validated by peptide-specific antibody production, ELISA, and immunofluorescence to determine cellular localization. RESULTS AND DISCUSSION: A total of 1,077 and 1,201 proteins were identified from E. histolytica and E. moshkovskii, respectively. The 801 of Entamoeba common proteins included kinases, GTPase-activating proteins, and heat shock proteins, reflecting conserved cellular processes. E. histolytica-unique proteins involved in nitrogen compound metabolism, vesicle-mediated transport, and catalytic activities, whereas E. moshkovskii proteins were related to lipid metabolism and environmental resilience. Subcellular localization revealed species-specific distribution of MmpL and AIG1-family proteins, suggesting potential roles in pathogenicity and host-immune response. A large proportion of hypothetical proteins was identified, highlighting gaps and opportunities for future study. CONCLUSIONS: Our study highlights conserved and divergent functions and cellular locations of Entamoeba species-specific proteins as insights for distinct pathogenicity and adaptation. MmpL and AIG1 proteins were proposed as potential targets for further diagnostic and therapeutic development.
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