Parasit Vectors [JOURNAL]
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200 papers
Impact of male-sterilizing doses and mating status on blood feeding rates and longevity in Aedes aegypti, Aedes albopictus, and Anopheles arabiensis females.
Yamada H, Somda NSB, Poda BS … +9 more , Kraupa C, Wallner T, Mamai W, Bourtzis K, Mashatola T, Kotla SS, de Beer CJ, Balestrino F, Bouyer J
Parasit Vectors · 2026 Mar · PMID 41864925 · Full text
The irradiation of female mosquitoes has been shown to influence blood feeding behavior, depending on dose, life stage at irradiation, and mating status. In sterile male releases during the sterile insect technique (SIT)...
The irradiation of female mosquitoes has been shown to influence blood feeding behavior, depending on dose, life stage at irradiation, and mating status. In sterile male releases during the sterile insect technique (SIT) programs, a small number of sterile females can be released accidentally, which may pose a manageable but nonnegligible risk regarding disease transmission. In this study, female Aedes aegypti, Aedes albopictus, and Anopheles arabiensis were exposed to gamma irradiation at male-sterilizing doses and the blood feeding rates and longevity of mated versus unmated sterile females were assessed. Although some differences were observed between the three species, generally females irradiated at the pupal stage showed a marked decrease in blood feeding rates, while irradiated adults showed slightly higher feeding rates, more pronounced in the second week (for Aedes spp.). Overall, blood feeding females irradiated as pupae that were mated died soonest, while in the non-blood fed groups, irradiation only correlated with negative effects on survival in Ae. aegypti, and mating status correlated with diminished survival in Ae. albopictus. Although the overall risk of a small number of mated, irradiated females participating in disease transmission in SIT programs is expected to be very low, rigorous sex separation and quality control will minimize this risk, and developing genetic sexing strains to ensure safety should be prioritized.
Knockout of aminopeptidase N3 confers resistance to low concentrations of Bacillus thuringiensis Cry4Ba protoxin in Aedes aegypti.
Yang X, Huang W, Wei J … +4 more , Xu X, Champer J, Zhang L, Wang J
Parasit Vectors · 2026 Mar · PMID 41862985 · Full text
BACKGROUND: Bacillus thuringiensis is widely employed for biological control. It can effectively suppress populations of various mosquito species, including Aedes aegypti. However, the precise mechanism underlying the ac...
BACKGROUND: Bacillus thuringiensis is widely employed for biological control. It can effectively suppress populations of various mosquito species, including Aedes aegypti. However, the precise mechanism underlying the action of Cry protein produced by Bacillus thuringiensis on Ae. aegypti remains elusive. On the basis of our previous research findings, five Aedes aminopeptidase N proteins (AeAPNs) were identified from the brush border membrane vesicles (BBMV) of Ae. aegypti that could bind to Cry4Ba or Cry11Aa. Further analysis confirmed that AeAPN1 and AeAPN2 are not functional receptors for these proteins. In this study, we investigated an additional aminopeptidase N (AeAPN3, AAEL012774) as a potential binding receptor for Cry proteins. METHODS: Comprehensive bioinformatics analysis involving whole-genome screening, genetic mapping, structural characterization, phylogenetic analysis, and spatiotemporal expression profiling were used to identify Ae. aegypti aminopeptidase N homologs. Ligand blotting and enzyme-linked immunosorbent assay (ELISA) were used to measure binding affinity to Cry4Ba. To elucidate its functional role as a potential receptor mediating Cry4Ba activity in Ae. aegypti midgut cells, AeAPN3 was knocked out with CRISPR/Cas9 technology. RESULTS: A total of 29 homologs of Ae. aegypti aminopeptidase N were identified in this study. Then, we expressed GST-APN3 fusion protein in E. coli and found that it had high-affinity binding to Cry4Ba protein (K = 20.53 nM). Mosquito larvae had approximately threefold higher resistance against Cry4Ba after AeAPN3 knockout, indicating its significant involvement as an active receptor mediating Cry4Ba activity. CONCLUSIONS: Overall, this study provides a foundation for elucidating the specific larvicidal mechanisms of Bacillus thuringiensis (Bt) against mosquito populations.
Correction: On the integrative taxonomy of Trichophoromyia Barretto, 1962 and its relationship with Nyssomyia Barretto, 1962 (Diptera, Psychodidae, Phlebotominae): species delimitation, phylogeny, genus and subgenus description.
Rodrigues BL, Vasconcelos Dos Santos T, Brilhante AF … +9 more , de Souza Pinto I, Rocha EG, Pereira Júnior AM, da Silva Costa G, de França KP, de Souza Cavalcante K, Shimabukuro PHF, Medeiros JF, Galati EAB
Parasit Vectors · 2026 Mar · PMID 41857640 · Full text
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Small particles of Echinococcus granulosus (spegs) and Echinococcus multilocularis (spems) promote follicular T helper cell expansion and are associated with IgE and IgG4 class switching in human lymph nodes.
Schreiber L, Zhang L, Grimm J … +4 more , Mellert K, Nell J, Möller P, Barth TFE
Parasit Vectors · 2026 Mar · PMID 41851909 · Full text
BACKGROUND: Cystic echinococcosis (CE) and alveolar echinococcosis (AE) are zoonotic diseases caused by the larval stages of Echinococcus granulosus and E. multilocularis. Prior studies have identified small particles fr...
BACKGROUND: Cystic echinococcosis (CE) and alveolar echinococcosis (AE) are zoonotic diseases caused by the larval stages of Echinococcus granulosus and E. multilocularis. Prior studies have identified small particles from the outer layer of parasitic lesions termed spegs (from E. granulosus) and spems (from E. multilocularis), which appear to interact with the human immune system, leading to lymph node enlargement. METHODS: We analyzed lymph nodes from CE (n = 3) and AE (n = 3) patients by immunohistochemical staining for spegs/spems and CD57. Automated image analysis revealed a significantly increased number of CD57-positive cells in Echinococcus particle-positive germinal centers compared with speg-/spem-negative germinal centers. Double immunofluorescence staining was used to characterize CD57-positive cells with markers for CD2, CD3, CD4, CD8, PD-1, Granzyme B, Perforin, and T-cell intracellular antigen 1 (TIA1). Additionally, IgG4 and IgE immunostaining was performed on liver lesions and lymph nodes containing spegs and spems and compared with unaffected controls. RESULTS: Spegs and spems were found to accumulate in the germinal centers of the lymph nodes. Affected germinal centers showed a higher number of CD57-positive cells, which coexpressed CD2, CD3, CD4, and PD-1 but lacked cytotoxic markers (CD8, Granzyme B, Perforin, TIA1), identifying them as follicular helper T cells (Tfh). Furthermore, the speg- and spem-affected liver and lymph node sections exhibited significantly increased numbers of IgG4-, IgE-, and CD57-positive cells. CONCLUSIONS: Spegs and spems are associated with changes in the host immune response, characterized by an increased accumulation of Tfh in germinal centers. This finding is accompanied by the presence of IgE and IgG4 plasma cells in the lymph node and the perilesional area, suggesting parasite-associated immunomodulatory processes in echinococcosis.
Integrated vector and arbovirus surveillance in Cyprus: first reports of Usutu virus and Culex pipiens bioform diversity highlight potential for zoonotic arbovirus transmission.
Sharma AA, Martinou AF, Cadar D … +3 more , Omirou M, Neira M, Christophides GK
Parasit Vectors · 2026 Mar · PMID 41851880 · Full text
BACKGROUND: Anthropogenic pressures, including urbanisation, globalisation and climate change, have facilitated an increased risk for emergence or re-emergence of mosquito-borne diseases into regions such as the Eastern...
BACKGROUND: Anthropogenic pressures, including urbanisation, globalisation and climate change, have facilitated an increased risk for emergence or re-emergence of mosquito-borne diseases into regions such as the Eastern Mediterranean and Middle East. Cyprus is a major stop-over site for migratory birds and has previously experienced outbreaks of West Nile virus (WNV). The island has native mosquito vector populations; however, it has also seen the recent establishment of invasive Aedes albopictus and Ae. aegypti mosquitoes. Given the dynamic climatic conditions and the shifting ecological and epidemiological landscapes in the region, the need for routine vector and pathogen surveillance has never been more critical. METHODS: Herein, we present the results from localised adult mosquito surveillance that were conducted in two cities of Cyprus between 2019 and 2022. Mosquito taxa were identified through morphological analysis, and molecular techniques were used to further characterise the Culex pipiens bioforms. Engorged mosquito midguts were analysed to determine host blood meals. Metagenomic next-generation sequencing was employed to screen mosquito pools for arboviruses. RESULTS: Our results provide the first report of Usutu virus in Cx. pipiens mosquitoes in Cyprus. Blood meal analysis identified multiple vertebrate hosts, including Cetti's warbler, a bird species previously reported to be seropositive for WNV on the island. Additionally, we report the presence of both Cx. pipiens pipiens and Cx. pipiens molestus, an ornithophilic and a mammophilic bioform, respectively, as well as their hybrids. CONCLUSIONS: Our findings highlight the urgent need for enhanced mosquito surveillance strategies where mosquito populations will be regularly screened for pathogens to mitigate emerging risks of arbovirus transmission in Cyprus.
Risk and protective factors for canine visceral leishmaniasis in the Americas: a systematic review update with meta-analysis.
Duarte AGS, Werneck GL, de Farias Lelis S … +8 more , da Silva ES, Dos Santos ÁO, Bruhn FRP, Gontijo TS, Donato LE, Barbosa DS, Soares PHA, Belo VS
Parasit Vectors · 2026 Mar · PMID 41851798 · Full text
BACKGROUND: Identification of risk and protective factors for canine visceral leishmaniasis (CVL) is essential to understand the epidemiology of the disease and direct prevention and control strategies. Building on a pre...
BACKGROUND: Identification of risk and protective factors for canine visceral leishmaniasis (CVL) is essential to understand the epidemiology of the disease and direct prevention and control strategies. Building on a previous systematic review, this study presents new findings relating to the associations between CVL and a range of variables. METHODS: The systematic review included articles from the previous review (up to September 2011) and additional studies published thereafter regarding factors associated with CVL in the American continent. The inclusion criteria encompassed studies that analyzed associations between CVL and socioeconomic, environmental, household-level, or dog-level variables, regardless of the diagnostic method employed. Meta-analyses were conducted using random-effects models and subgroup analyses, while the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to classify levels of evidence. RESULTS: Of the 111 studies included in the analysis, the vast majority were cross-sectional (87.4%), conducted in Brazil (95.5%), and employed serological diagnostic tests alone (77.5%). The variables most consistently associated with CVL, based on moderate levels of evidence, were short-haired dogs, dogs dwelling in the peridomicile or with free access to the street, and proximity of the domicile to green areas. Male dogs, large dogs, ectoparasite-infested animals, dogs in contact with horses, and living in homes with yards also had higher odds of infection, although the levels of evidence were low. Other variables associated with CVL but assigned with very low levels of evidence included the presence of chickens, cats, sand flies, and other dogs in the dog environment; previous cases of CVL in the domicile; substandard custodianship; and guardians with poor education and low income. The quality of the studies has improved since the last review, although methodological limitations were still present, in particular, the absence of control for confounders. CONCLUSIONS: The analyses performed in this review strengthen the current knowledge of CVL and highlight the importance of further research to better understand some of the associated variables. Additional cohort and case-control studies are required, particularly those utilizing molecular diagnostics and adequate control for confounding factors. This review represents progress in understanding the determinants of CVL in the Americas and provides support for improving prevention and control strategies.
Current issues in heartworm chemotherapy.
Geary TG
Parasit Vectors · 2026 Mar · PMID 41851772 · Full text
Several issues that affect prevention and treatment of heartworm infections require more intensive research. The incidence of heartworm infection in the USA is increasing, but the factors that underlie this trend remain...
Several issues that affect prevention and treatment of heartworm infections require more intensive research. The incidence of heartworm infection in the USA is increasing, but the factors that underlie this trend remain incompletely understood. The contributions of climate change, vector range expansion, client compliance and resistance to macrocyclic lactones (ML) are likely interrelated and require investigation. Molecular-level research has not yet identified the causative mechanisms underlying ML resistance (MLR), but surveys of genomic markers associated with the trait reveal worrying trends in the presence and frequency of these resistance alleles. Research is needed to confirm the phenotypic relevance of these markers and to identify the gene(s) responsible for it. Developing highly inbred strains of MLR heartworms may be necessary but would require multigenerational studies of targeted breeding of selected parasites in dogs. A second issue of concern for veterinarians is the increasing extra-label use of emodepside products for the treatment of multiple anthelmintic drug resistant (MADR) canine hookworms (Ancylostoma caninum), which are already common throughout the USA. Emodepside is not approved for use in dogs in the USA, but a cat topical product containing the drug is, and is being used orally in hookworm-infected dogs. Emodepside has activity against larval and adult stages of many filarial parasites and the safety of this drug in heartworm-infected dogs has not been reported. It is perhaps unlikely that such studies will be undertaken, given the lack of economic motivation. Nonetheless, a review of the relevant literature leads to the conclusion that the status of heartworm infection in a dog bearing an apparently MADR hookworm infection be determined before starting treatment with emodepside, with caution exercised should it ensue.
Spatial distribution of urogenital schistosomiasis in school-aged children in Togo: an oversampling survey in three districts in 2022.
Ataba E, Lack FA, Kamassa HE … +13 more , Alidou S, Yakpa K, Fleming FM, Sossou E, Hemou M, Tchalim M, Datagni G, Seim A, Gnossike P, Vounatsou P, Pullan R, Gass K, Dorkenoo AM
Parasit Vectors · 2026 Mar · PMID 41851746 · Full text
BACKGROUND: Despite concerted global efforts, urogenital schistosomiasis remains an important public health challenge in sub-Saharan Africa. Understanding the local dynamics of this disease is crucial for effectively pla...
BACKGROUND: Despite concerted global efforts, urogenital schistosomiasis remains an important public health challenge in sub-Saharan Africa. Understanding the local dynamics of this disease is crucial for effectively planning interventions to eliminate urogenital schistosomiasis as a public health concern. This study, conducted in southern Togo, aimed to comprehensively describe the epidemiology of Schistosoma haematobium infection among school-aged children after more than a decade of control using preventive chemotherapy. METHODS: A cross-sectional study was conducted from July to August 2022 among children aged 5 to 14 years in selected villages across three districts of the Plateaux region of Togo. Coordinates of each surveyed household were recorded, and sociodemographic data were gathered using a pre-tested questionnaire. Urine samples were visually examined for macrohematuria and tested for microhematuria. Urine filtration was performed to quantify S. haematobium eggs. RESULTS: In total, 3146 households were enrolled, and 6400 school-aged children provided urine samples. The overall prevalence of macrohematuria was 4.48% (95% CI [4.21-4.75]) and of microhematuria was 16.11% (95% CI [15.65-16.57]), while 15.0% (95% CI [14.55-15.45]), of children were S. haematobium egg-positive. Prevalence varied across villages and districts, with Ogou district exhibiting the highest prevalence by all three indicators. The prevalence of heavy-intensity infection ranged from 0.92% (95% CI [0.69-1.15]) in the Est-Mono district to 12.91% (95% CI [12.3-13.52]) in the Ogou district, averaging 3.40% (95% CI [2.95-3.85]) in the Anié district. CONCLUSIONS: This study highlights geographic variability in the distribution of S. haematobium, even after more than a decade of PC. The detailed data provided can support the development of more targeted treatment strategies, focusing on areas where S. haematobium remains prevalent. This approach may accelerate progress toward achieving the WHO goal of eliminating schistosomiasis as a public health concern.
Detection of supergroup B Wolbachia strains and their co-infection with Plasmodium falciparum in wild Anopheles funestus in southeastern Tanzania: implications for malaria control.
Mmweteni RE, Philbert AB, Mkandawile G … +12 more , Abilahi F, Abbasi S, Msemo J, Milonge S, Tumbo FA, Mwalugelo Y, Muyaga LL, Msaky D, Kipekepeke AR, Okumu FO, Kaindoa EW, Baldini F
Parasit Vectors · 2026 Mar · PMID 41845520 · Full text
BACKGROUND: Evidence of natural infection with Wolbachia and its negative correlation with Plasmodium falciparum among wild malaria vectors has opened new avenues for utilization of Wolbachia in malaria vector control. H...
BACKGROUND: Evidence of natural infection with Wolbachia and its negative correlation with Plasmodium falciparum among wild malaria vectors has opened new avenues for utilization of Wolbachia in malaria vector control. However, the interaction between Wolbachia and Plasmodium parasites in mosquitoes tends to be species-specific and may show ecological variations. Among the primary malaria vectors in Tanzania, natural Wolbachia infection has only been observed in Anopheles arabiensis, while there is still limited information on Wolbachia natural infection in Anopheles funestus sensu lato, and its interaction with P. falciparum in the mosquito species. Therefore, this study investigated the prevalence of natural infection and co-infection of Wolbachia and P. falciparum in the An. funestus s.l. in southeastern Tanzania, and characterized the Wolbachia strains detected. METHODS: The study was conducted in five villages in southeastern Tanzania between March and June 2024. Mosquitoes were collected from 52 households using Centers for Disease Control and Prevention (CDC) light traps and Prokopack aspirators, followed by morphological identification. Detection of An. funestus sibling species and Wolbachia was performed using conventional polymerase chain reaction (PCR) and nested PCR (Wolbachia only). Sanger sequencing was performed as a confirmatory test followed by phylogenetic analysis of the detected Wolbachia strains. P. falciparum sporozoites were detected using enzyme-linked immunosorbent assay (ELISA). RESULTS: Wolbachia was detected in almost half of all wild An. funestus s.l. tested using the primary PCR (prevalence = 46.5%, N = 400); and more than half when nested PCR approach was used (prevalence = 70.8%, N = 400). Only three mosquitoes carried P. falciparum sporozoites (prevalence = 0.8%, N = 400) and only one showed co-infection with Wolbachia (prevalence = 0.3%, n = 400). Sequencing and phylogenetic analysis involving both the 16S rDNA, coxA, and wsp Wolbachia genes showed that the detected strains clustered with Wolbachia supergroup B, specific for Dipterans. CONCLUSIONS: Unlike findings from the previous study, this study demonstrates that An. funestus s.l. in southeastern Tanzania are infected with Wolbachia, at a surprisingly high prevalence. This study also provides the first report on Wolbachia-P. falciparum co-infection status in An. funestus s.l. in Tanzania. Further studies with larger sample sizes are needed to confirm the association between native Wolbachia and P. falciparum in wild An. funestus s.l. in southeastern Tanzania.
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 Mar · PMID 41845479 · Full text
The Post-Kala-Azar Dermal Leishmaniasis (PKDL) Consortium convened its seventh meeting from 28 to 29 November 2024 in Kolkata, India, to advance research and public health strategies related to PKDL and visceral leishman...
The Post-Kala-Azar Dermal Leishmaniasis (PKDL) Consortium convened its seventh meeting from 28 to 29 November 2024 in Kolkata, India, to advance research and public health strategies related to PKDL and visceral leishmaniasis. This report summarizes the key discussions and outcomes of the meeting and proposes a way forward for addressing the last-mile challenge of eliminating leishmaniasis as a public health problem in South Asia and subsequently East Africa.
Efficacy of Revolution Plus (selamectin plus sarolaner) for the prevention of transmission of Borrelia burgdorferi from infected Ixodes scapularis to cats.
Isdale R, Myers JAE, Holzmer S … +5 more , Shaw K, King V, Rodriguez JY, Hawley J, Lappin MR
Parasit Vectors · 2026 Mar · PMID 41845441 · Full text
BACKGROUND: Borrelia burgdorferi and Anaplasma phagocytophilum are transmitted by Ixodes spp., with antibodies having been detected in cats in endemic areas. The combination of selamectin plus sarolaner (Revolution Plus/...
BACKGROUND: Borrelia burgdorferi and Anaplasma phagocytophilum are transmitted by Ixodes spp., with antibodies having been detected in cats in endemic areas. The combination of selamectin plus sarolaner (Revolution Plus/Stronghold Plus; Zoetis; RP) is effective against Ixodes spp. for 1 month. The objective of this study was to determine whether RP protects cats against transmission of B. burgdorferi from Ixodes scapularis by killing the ticks before transmission occurs. Transmission of A. phagocytophilum was also monitored. METHODS: Ten cats per group were treated once topically either with placebo solution (0.1 ml/kg) or with the minimum label dose of RP (6.0 mg/kg selamectin plus 1.0 mg/kg sarolaner). Thirty days post-treatment, cats were infested with 50 wild-caught adult I. scapularis. Ticks were counted, categorized, and removed on day 35. Blood collections for serology occurred on days -6, 30 (prior to infestation), 49, 63, 77, 91, and 104. Serum antibody assay results (B. burgdorferi and A. phagocytophilum) and polymerase chain reaction (PCR) of skin biopsies (B. burgdorferi) were used to define infection rates in the cats. RESULTS: Treatment with RP resulted in a 100% reduction of I. scapularis ticks compared with placebo-treated cats. In placebo-treated cats, antibodies against B. burgdorferi, A. phagocytophilum, both agents, and B. burgdorferi DNA in skin (five, nine, six, and three cats, respectively) were detected by day 104. In contrast, none of the RP-treated cats developed B. burgdorferi antibodies or DNA in skin biopsies, and A. phagocytophilum antibodies were detected in only two cats, significantly lower than in placebo-treated cats. CONCLUSIONS: Results suggest that a single application of RP at the minimum label dose reduces the risk of infection by both B. burgdorferi and A. phagocytophilum, when infected at the end of the dosing interval.
Diagnostic potential of a multi-antigen ELISA for feline leishmaniosis.
Lima CM, Felgueiras Ó, Brito M … +8 more , Carbonara M, Otranto D, Magalhães A, Ferreira R, Tavares J, Cardoso L, da Silva AC, Santarém N
Parasit Vectors · 2026 Mar · PMID 41840735 · Full text
BACKGROUND: Leishmania infantum is a sand fly-transmitted zoonotic protozoan, endemic in the Mediterranean basin and responsible for human, canine (CanL), and feline (FeL) leishmaniosis. While dogs are the primary reserv...
BACKGROUND: Leishmania infantum is a sand fly-transmitted zoonotic protozoan, endemic in the Mediterranean basin and responsible for human, canine (CanL), and feline (FeL) leishmaniosis. While dogs are the primary reservoir host, a growing number of FeL cases have been reported in this region despite the absence of pathognomonic clinical signs and limited diagnostic tools. Herein, we evaluate the performance of seven serological tools for CanL in detecting antibodies to Leishmania in cats, aiming to improve FeL diagnosis. METHODS: Five ELISAs based on Leishmania-specific antigens (soluble promastigote Leishmania antigens, SPLA; recombinant Leishmania proteins K39 [rK39], K28, and KDDR, and L. infantum cytosolic peroxiredoxin, LicTXNPx), indirect fluorescent antibody test (IFAT), and direct agglutination test (DAT) were compared for detecting anti-Leishmania antibodies in 274 cats. Blood samples from the same cats were molecularly tested. Statistical analysis was performed based on clustering of multivariate serological data. Reference serological profiles were first defined in a control group. Study group data were subsequently classified according to these profiles, with principal component analysis used for dimensionality reduction and graphical representation. Associations between seropositivity and clinicopathological alterations were determined using seropositivity thresholds. RESULTS: Cats exhibited attenuated and heterogeneous antibody responses to L. infantum serological tests. Agreement between individual tests was variable, with poor concordance when single markers were considered. Multivariate analysis, based on clustering of serological responses, showed that positivity to multiple antigens was associated with clinically affected cats. Positivity to multiple Leishmania-specific ELISA antigens was associated with diverse clinical presentations and prognostic laboratory alterations, including anaemia, thrombocytopenia, and hypergammaglobulinaemia. CONCLUSIONS: Integrating multi-antigen ELISA, particularly rK39, SPLA, and LicTXNPx, into FeL diagnostic workflows, alongside molecular and clinical assessment, improves epidemiological surveillance, early detection, and disease management. These findings support the development of serological strategies tailored to feline hosts for enhanced surveillance and management.
Onchocerca volvulus infection prevalence and intensity in Logo and Nyarambe Health Zones in Ituri, Democratic Republic of the Congo in 2010 and in 2021-2023: results of screening for clinical trials of moxidectin versus ivermectin.
Ngave FN, Wonyarossi DU, Abhafule GM … +23 more , Mande JL, Nyathirombo A, Uvon CB, Raciu AA, Mandro M, Adroba PT, Ukety TO, Mananu IA, Abeditho GL, Upenjirwoth JU, Aliang'o CM, de Dieu N Unega J, Nigo MM, Bakajika D, Uvoyo JU, Mambandu GL, Halleux CM, Vaillant M, Schritz A, Mosqueira B, Mumbere M, Kinrade S, Kuesel AC
Parasit Vectors · 2026 Mar · PMID 41840733 · Full text
BACKGROUND: In Ituri Province, 7576 and 1056 volunteers living in Logo and Nyarambe Health Zone (HZ), respectively, were screened in 2021-2023 for two studies comparing moxidectin and ivermectin in individuals with ≥ 0 O...
BACKGROUND: In Ituri Province, 7576 and 1056 volunteers living in Logo and Nyarambe Health Zone (HZ), respectively, were screened in 2021-2023 for two studies comparing moxidectin and ivermectin in individuals with ≥ 0 Onchocerca volvulus skin microfilariae density (SmfD, microfilariae/mg skin). Site selection was based on the trial capacity established for the moxidectin Phase 3 study and SmfD measured among 1373 and 36 individuals screened in HZ Logo and Nyarambe, respectively, in 2010. We compared the SmfD measured in 2010 and 2021-2023 in Logo HZ where ivermectin mass administration was never implemented and provide descriptive statistics for SmfD from Nyarambe HZ. METHODS: Four skin snips from each consenting/assenting individual ≥ 12 years old were weighed and incubated in isotonic saline for ≥ 8 h. Emerged microfilariae were counted and SmfD calculated as the mean of the microfilariae/mg skin of each snip. Other data collected included age, gender, village of residence, and history of ivermectin treatment. RESULTS: In 2010 and 2021-2023, respectively, adults (18-93 years old) represented 92.1% and 73.2%, and women 36.9% and 46.6% of the 1373 and 7547 volunteers from Logo HZ without reported prior ivermectin treatment. Among these adults and adolescents (12-17 years), no microfilariae were detected in snips from 23.3% and 26.9% in 2010 and 89.8% and 96.8% in 2021-2023, respectively, with mean ± standard deviation SmfD being 24.30 ± 35.52 and 11.8 ± 18.37 in 2010 and 1.1 ± 6.44 and 0.3 ± 2.62 in 2021-2023, respectively. CONCLUSIONS: Given that the reduction in infection prevalence and intensity in Logo HZ cannot be attributed to ivermectin distribution, it has to be due to reduction in infective vector biting rates, possibly linked to a recently proposed change in vector species triggered by land-use changes. Because SmfD reflects transmission events approximately 2-15 years earlier, infective vector biting rate assessment is needed to determine current transmission rates. Reduced transmission shifts macrofilariae age distribution toward older macrofilariae with lower reproductive capacity. Comparison of the results from the Phase 3 and the ongoing efficacy study might help determine whether drug susceptibility changes significantly with macrofilariae age. Should that be the case, transmission models evaluating the impact of mass drug administrations could be adjusted.
Signal peptide variation in cyst lectins as a potential marker for pathogenic Acanthamoeba spp.
Tsai CM, Cheng WH, Lin WC
Parasit Vectors · 2026 Mar · PMID 41840427 · Full text
BACKGROUND: Acanthamoeba species are free-living protists widely distributed in natural and artificial environments, including freshwater, soil, and water-associated facilities. Some isolates can cause opportunistic huma...
BACKGROUND: Acanthamoeba species are free-living protists widely distributed in natural and artificial environments, including freshwater, soil, and water-associated facilities. Some isolates can cause opportunistic human infections, such as Acanthamoeba keratitis and granulomatous amoebic encephalitis. The life cycle of Acanthamoeba includes an active trophozoite stage and a dormant cyst stage. The cyst is surrounded by a complex double-layered wall composed of cellulose and multiple structural proteins, including cyst wall lectins. While the architecture and molecular composition of the cyst wall have been investigated, inter-isolate sequence variation of cyst wall components remains poorly characterized. METHODS: We performed a genome-based comparative analysis of 31 previously characterized cyst wall lectins, analyzing the homologous sequence of each lectin across 31 publicly available Acanthamoeba genomes. Isolates were classified as clinical or environmental on the basis of their reported sources. Sequence similarity-based clustering was conducted to identify lectins associated with clinical isolates. For selected genes, sequence features at the 5' region were further examined and experimentally validated by polymerase chain reaction using long-term axenic clinical isolates maintained at National Cheng Kung University Hospital. RESULTS: Similarity-based clustering identified eight cyst wall lectins that formed clusters enriched for clinical isolates. Among these, three lectins showed pronounced sequence variation at the 5' region in multiple clinical isolate genomes. Polymerase chain reaction (PCR) validation confirmed that these variations were present in clinical isolates and were not attributable to genome assembly artifacts. Sequence analysis suggested that these variations may affect signal peptide features at the amino terminus of the proteins. CONCLUSIONS: Our findings reveal previously underexplored sequence diversity in cyst wall lectins across Acanthamoeba isolates. This diversity may contribute to differences in cyst wall architecture between clinical and environmental isolates. These results provide new insight into cyst-associated molecular features that may be linked to pathogenic potential and offer a foundation for future studies on cyst-mediated adaptation and infection.
Scabies among Dutch higher education students: do cases notify their contacts and do contacts take adequate measures?
Stolk WA, Stradmeijer MD, Voeten HACM … +3 more , Lewis-van Disseldorp IM, de Zwart-Slats D, Mevissen FEF
Parasit Vectors · 2026 Mar · PMID 41840400 · Full text
BACKGROUND: Scabies incidence has rapidly increased in the Netherlands, particularly among higher education students. We hypothesized that effective control in this group is hindered by poor contact notification by index...
BACKGROUND: Scabies incidence has rapidly increased in the Netherlands, particularly among higher education students. We hypothesized that effective control in this group is hindered by poor contact notification by indexes and limited treatment by contacts. We assessed this in a questionnaire study. METHODS: An online questionnaire was distributed to students, focusing on their adherence to notification (indexes), and treatment and hygiene recommendations (contacts), as well as their health seeking behaviour. RESULTS: Of the indexes (n = 308), 59% had experienced multiple scabies episodes and almost two-thirds had not been notified beforehand. Notably, 48% self-diagnosed their condition. Most indexes notified all regular (bed) partners and housemates, 53% also notified all casual bed partners. Contacts (n = 269) were usually notified by the index; in 57% of cases the notifier was a housemate. After notification, many contacts washed their bedding (85%), washed their clothes or put them in bags (81%); applied permethrin/benzoate cream (78%), avoided physical contact with others (74%); many also notified their own contacts (59%). The general practitioner was frequently contacted, especially by indexes, although experiences were often rated poorly owing to conflicting or incorrect information. CONCLUSIONS: The high proportion of unnotified indexes suggests a notification gap. Especially casual bedpartners often remain unnotified, presenting a risk for onward transmission. Contacts generally took adequate measures, although premature notification of their contacts may lead to unnecessary treatment or 'notification fatigue.' Enhancing healthcare support and communication might help to improve notification and prophylactic treatment behaviours and may play a crucial role in breaking the chain of transmission.
Single-cell transcriptomics reveals lipid metabolism reprogramming in macrophages in vitro during early stages of Leishmania donovani infection.
Li FR, Sun Q, Wang Q … +4 more , Qu LL, Li ZH, Yi ZJ, Yang BB
Parasit Vectors · 2026 Mar · PMID 41827050 · Full text
BACKGROUND: Leishmania donovani can cause visceral leishmaniasis, clinically manifested as fever, hepatosplenomegaly, and anemia. If left untreated, it may lead to death owing to complications from other diseases and inf...
BACKGROUND: Leishmania donovani can cause visceral leishmaniasis, clinically manifested as fever, hepatosplenomegaly, and anemia. If left untreated, it may lead to death owing to complications from other diseases and infections. However, the pathogenesis of L. donovani infection remains unclear. METHODS: In this study, we utilized single-cell transcriptomic sequencing technology to analyze the transcriptomic landscape of macrophages infected with L. donovani in mice. RESULTS: The results showed that the parasite infection rate within macrophages gradually decreased over time. By comparing the transcriptomic profiles of infected cells, bystander cells, and unexposed cells, we identified precise modulation of several key pathways: first, the "Fabp4/Cd36 lipid metabolism pathway" is activated during early infection. Significant changes in genes such as Fabp4 are observed in infected cells, suggesting that the parasite hijacks the host lipid metabolic pathway to create a lipid sanctuary. Additionally, as the duration of infection increases, aging-related genes Plk1, Cenpa, Bub1b, H2afx, and Cdkn2d were activated, suggesting that infection may initiate cellular senescence. Meanwhile, infected cells mediated coordinated immune responses in bystander cells through secretory signals, as evidenced by concurrent expression trends of genes such as Il1rn, Ccl3, and Hmox1 in both cell types. Further analysis revealed that parasite gene expression levels were significantly higher in M2 macrophages than in M1 macrophages, indicating that an M2-polarized microenvironment is more conducive to intracellular parasite survival. Additionally, parasite gene expression profiling revealed transcriptional remodeling characteristics during the transition from promastigotes to amastigotes, manifested as a significant decrease in the total number of expressed genes over time. CONCLUSIONS: This study analyzed the host immune response process and the characteristics of parasite-host interactions during L. donovani infection, which may provide a theoretical basis for the development of novel anti-infective treatment strategies in the future.
Biochemical, molecular, and in silico insights into the effects of cyphenothrin on Culex quinquefasciatus mosquitoes.
Saha A, Das S, Das P … +4 more , Ghosh S, Tamang A, Thakur S, Saha D
Parasit Vectors · 2026 Mar · PMID 41827045 · Full text
BACKGROUND: Cyphenothrin, a type II synthetic pyrethroid, is widely recommended by the World Health Organization (WHO) for control programs for mosquitoes such as Culex quinquefasciatus. This cosmopolitan mosquito specie...
BACKGROUND: Cyphenothrin, a type II synthetic pyrethroid, is widely recommended by the World Health Organization (WHO) for control programs for mosquitoes such as Culex quinquefasciatus. This cosmopolitan mosquito species plays a pivotal role in transmitting several neglected tropical diseases, including lymphatic filariasis, West Nile virus, Japanese encephalitis, and so on. Besides treatment, vector control programs heavily rely on insecticides, leading to varying resistance due to prolonged exposure. METHODS: The present study assessed the susceptibility status of field-collected Cx. quinquefasciatus larvae from two filarial endemic districts of sub-Himalayan West Bengal against cyphenothrin. All the wild populations have been exposed to their respective lethal concentration doses. Monooxygenase levels and carboxylesterase activities were quantified both in the wild and cyphenothrin-exposed populations. The expression profiles of selected carboxylesterase (esterase A and esterase B) and CYP450 (CYP6AA7, CYP9J40, and CYP9J45) genes were also assessed. Molecular docking analyses were performed to evaluate the binding affinities and interaction mechanisms of cyphenothrin with the selected proteins. RESULTS: Most of the populations showed elevated resistance status to cyphenothrin. In enzymatic assays, elevated levels of monooxygenases and carboxylesterases are found both in the wild and cyphenothrin-exposed populations. The expression profiles of selected CYP450s and carboxylesterase genes indicated an upregulation in the studied wild and exposed populations. Furthermore, molecular docking simulations corroborated the strong binding affinities of cyphenothrin to these detoxification enzymes. CONCLUSIONS: These findings suggest the involvement of a few detoxifying genes in resistance development against cyphenothrin in Cx. quinquefasciatus mosquitoes and advocates the urgent need for regular resistance monitoring, molecular surveillance, gene knockdown studies, and incorporation of synergists into integrated vector management frameworks to sustain effectiveness of mosquito control programs.
Programmatic implementation of Ovicol ovitraps for Aedes spp. control in Colombia: operational adherence, effectiveness and comparisons with AGO and BG-Sentinel traps.
Mosquera L, Osorio J, Herrera O … +1 more , Montenegro D
Parasit Vectors · 2026 Mar · PMID 41827031 · Full text
BACKGROUND: The global expansion of Aedes aegypti and Aedes albopictus mosquitoes has intensified arboviral epidemics, generating annual socio-economic losses exceeding 2 billion US dollars, mainly in the Americas. The d...
BACKGROUND: The global expansion of Aedes aegypti and Aedes albopictus mosquitoes has intensified arboviral epidemics, generating annual socio-economic losses exceeding 2 billion US dollars, mainly in the Americas. The desiccation-resistant egg stage plays a key role in mosquito persistence and spread, yet this developmental stage remains insufficiently targeted by current control strategies. In this context, the objective of this study was to evaluate the operational feasibility and effectiveness of a low-cost, handcrafted ovitrap (Ovicol) using two types of bioattractants, implemented by two territorial health entities (Entidades Territoriales de Salud [ETSs]) in Colombia, and to compare its performance with that of industrial autocidal gravid ovitraps (AGO) and BG-Sentinel (BGS) traps METHODS: Ovicol traps were baited with bird seed or molasses + yeast bioattractants. In Santa Marta, traps were installed in public areas (markets, cemeteries, sports complexes) using diflubenzuron as insecticide; in San José del Guaviare, the traps were deployed in buildings (hotels, schools, health centers) using a combination of diflubenzuron and Bacillus thuringiensis israelensis (BTi) as insecticide treatment. Data were analyzed through descriptive statistics, analysis of variance/chi-square test, nonparametric tests and spatial cluster detection. RESULTS: In Santa Marta, 41,677 eggs (100% Ae. aegypti) were eliminated and inactivated in 5 weeks. The Oviposition Positivity Index (OPI) ranged from 40.6% to 74.5%, with up to 88% of traps lost to the study at one site due to vandalism. In Guaviare, Ovicol traps registered oviposition within 24 h and outperformed AGO in terms of Aedes detection (65.2% vs. 30.8%, respectively; r = 0.87; P < 0.001). The fermented bird seed attractant achieved higher positivity (Kruskal-Wallis H = 9.42; P = 0.009). Compared with BGS traps, Ovicol showed superior stability in the field, with BGS traps limited by ≥ 70% rate of electrical disconnection during weekends, and low concordance (kappa: - 0.17). CONCLUSIONS: Ovicol is a cost-effective, operationally simple, and eco-sustainable tool for Aedes surveillance and control. By outperforming AGO and complementing BGS traps, Ovicol enhances spatiotemporal resolution for early microfocus detection and targeted response. Acting as a lethal trap, one diflubenzuron tablet (normally for 200 l) can treat approximately 800 Ovicol (0.25 L each), extending coverage to approximately 800 households and achieving an approximately 800-fold increase in larvicide efficiency. These findings support Ovicol's incorporation into national programs to promote sustainable, community-driven integrated vector management.
A tiger is not always a satyr: role of male mating behaviour in interspecific mating interactions between Aedes aegypti and Aedes albopictus.
Vollans M, Zhang C, Alfonso-Parra C … +4 more , Paaijmans KP, Gubbins S, Bonsall MB, Cator LJ
Parasit Vectors · 2026 Mar · PMID 41827030 · Full text
BACKGROUND: Interspecific mating between Aedes aegypti and Aedes albopictus, which act as vectors of a wide range of arboviruses, is predicted to have an important influence on their future distributions and disease cont...
BACKGROUND: Interspecific mating between Aedes aegypti and Aedes albopictus, which act as vectors of a wide range of arboviruses, is predicted to have an important influence on their future distributions and disease control efforts. While interspecific insemination has been documented in a range of laboratory and field studies, rates vary between populations. It has been suggested that the outcome of mating interactions is driven by evolved variation in both the male ability to mate interspecific females and ability of females to resist interspecific males. However, there has been relatively little dissection of the behaviours that underlie interspecific insemination rates. METHODS: We compared insemination rates between sympatric, allopatric, and lab-adapted strains of Ae. aegypti (Colombia, Arizona, and Liverpool, respectively) and allopatric and sympatric strains of Ae. albopictus (Montpellier and Colombia, respectively). We then used both live observations and high-speed videography to compare intraspecific and interspecific mating interactions. RESULTS: We found very low rates of interspecific mating across all strains used. Both behavioural observations and high-speed videography suggested that female resistance behaviours were not responsible for low interspecific mating. Interestingly, we documented male Ae. albopictus consistently aborting interspecific mating attempts. CONCLUSIONS: This study provides additional evidence for strong pre-copulatory species barriers between Ae. aegypti and Ae. albopictus and adds male avoidance as a possible mechanism to maintain these barriers. Considering female resistance, the ability of males to overcome that resistance, and male avoidance of interspecific matings together will be important for informing understanding of how we expect interspecific mating rates to vary across populations and respond to selective pressures such as mass-release strategies.
Control and mitigation of dengue and Zika virus transmission in a hospital in Recife, Brazil: a successful experience with an integrated control program against Aedes aegypti.
Candida-Silva HE, Ferreira HRP, Mendonça JA … +9 more , da Silva RA, Krokovsky L, Martins LO, Barbosa KEDS, Ribeiro FJ, de Oliveira CMF, Ayres CFJ, Paiva MHS, de Melo-Santos MAV
Parasit Vectors · 2026 Mar · PMID 41827002 · Full text
BACKGROUND: The presence of Aedes aegypti in healthcare facilities represents a significant epidemiological threat, as it is the primary vector of dengue (DENV), Zika (ZIKV), and chikungunya (CHIKV) viruses. In the absen...
BACKGROUND: The presence of Aedes aegypti in healthcare facilities represents a significant epidemiological threat, as it is the primary vector of dengue (DENV), Zika (ZIKV), and chikungunya (CHIKV) viruses. In the absence of effective alternatives to chemical insecticides for eliminating adult mosquitoes, healthcare facilities may become focal points for arbovirus transmission, compromising the safety of patients and healthcare employees. Vector control remains the main approach for mitigating arbovirus transmission. This study investigated the impact of an effective integrated control program (ICP) implemented in a hospital in Recife, Pernambuco, Brazil, where arbovirus circulation in mosquitoes was detected. METHODS: Entomological monitoring was conducted through mechanical aspiration inside the Hospital das Clínicas (HC). Specimens were counted, identified, grouped by species, classified according to blood-feeding status, and recorded by capture station. Viral infection was assessed using nonstructural protein 1 (NS1) by enzyme-linked immunosorbent assay (ELISA) and a triplex reverse transcription quantitative polymerase chain reaction (RT-qPCR) for the detection of DENV, ZIKV, and CHIKV. Infection rates were calculated using the minimum infection rate (MIR). ICP actions included environmental management, larvicide application at breeding sites, ovitraps to collect and destroy eggs, toxic sugar baits, and intensified mechanical aspiration to eliminate adult mosquitoes. Three phases were defined: pre-ICP (initial survey), ICP (all actions), and post-ICP (larvicidal treatment). RESULTS: During the ICP, a sustained reduction in female mosquito density was observed, reaching 99% for Ae. aegypti and 88% for Culex quinquefasciatus. Six months after ICP, ELISA detected infected females in 9 of 14 stations (64%). The MIR for Ae. aegypti decreased from 50 to 44, while Cx. quinquefasciatus showed a slight increase. RT-qPCR revealed 11 ZIKV-positive pools (eight Ae. aegypti and three Cx. quinquefasciatus). After 12 months of ICP, only one Ae. aegypti DENV-positive pool was detected by both techniques in a single station (pediatrics). Both techniques detected infection even in pools containing a single female, underscoring their high sensitivity. At 18 months of ICP, all pools tested negative for arboviruses. CONCLUSIONS: Molecular and antigen-based approaches confirmed the mitigation of arbovirus circulation in hospital-associated mosquitoes, demonstrating that the continuous elimination of Ae. aegypti females (> 99%) is critical in these settings to prevent nosocomial transmission.
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