Search Results (49)

Urban coastal wetlands constitute important ecological interfaces where human activities, wildlife, and arthropod vectors interact, potentially increasing the risk of pathogen transmission. In the city of Veracruz, Mexico, several interdunal lagoons have been incorporated into urban areas and are intensively used for recreational activities; however, information on their mosquito fauna remains limited. This study aimed to characterize mosquito species composition, abundance, and diversity in three urban recreational interdunal lagoons in Veracruz. Adult mosquitoes were collected weekly during the rainy season (June–September) 2023 using CDC light traps. Specimens were identified based on morphological characters using standard taxonomic keys, including genitalia dissections for male specimens when necessary. Species richness, sampling completeness, and community structure were evaluated using non-parametric richness estimators, diversity indices, species accumulation curves, and similarity analyses. A total of 1465 adult mosquitoes belonging to 11 species and five genera were collected. Mosquito assemblages were characterized by low species richness and a marked dominance of Culex panocossa and Culex quinquefasciatus across all lagoons. Diversity indices were low, and species composition showed a high degree of similarity among sites. Notably, Uranotaenia apicalis was recorded for the first time in the state of Veracruz, expanding its known geographical distribution. These findings indicate that urban interdunal lagoons support simplified mosquito communities dominated by disturbance-tolerant species, highlighting their potential epidemiological relevance and the need for targeted vector surveillance in urban coastal environments. Full article

Oropouche fever (OF), caused by Oropouche virus (OROV), has expanded beyond its Amazonian range into Minas Gerais (MG), Brazil, raising concern about transmission in extra-Amazonian Atlantic Forest landscapes. Critical gaps persist regarding Culicoides vector communities, anthropophily, and climate-sensitive transmission risk in these newly affected regions. We conducted targeted entomological surveys outbreak-driven by human OF cases, standardized across five MG communities using CDC light traps and Protected Human Attraction (PHA) to characterize Culicoides composition. Females of Culicoides underwent RT-qPCR for OROV (n = 819) and physiological assessment (n = 312). We developed an entomological alert framework that integrates blood-fed abundance, minimum infection rate (MIR) upper confidence bounds, and environmental drivers (i.e., mean temperature, relative humidity and precipitation) via generalized additive mixed models, which explained 68% of the variability in Culicoides abundance and the alert index across communities. We collected 1171 Culicoides individuals representing five species (C. leopoldoi, C. paraensis, C. pusillus, C. foxi, and C. limai). C. leopoldoi (79.1%) and C. paraensis (20.3%) were the predominant species; notably, C. paraensis is recognized as the primary vector of OROV in the Americas. C. paraensis was documented for the first time in all five outbreak areas and dominated PHA captures (90%), suggesting anthropophily. Although no specimens tested OROV-positive (consistent with expected field infection rates of 0.01–1%), MIR upper bounds reached 132/1000 in low-sample settings and humidity and temperature strongly modulated abundance. This operational baseline and alert index transform virologically negative, sparse surveillance data into prioritized targets for intensified sampling and vector control during early, low-prevalence phases, when containment of OROV’s extra-Amazonian spread is still achievable. Full article

Visceral leishmaniasis (VL) is a zoonosis of major public health importance. In urban areas, Lutzomyia longipalpis is the primary vector of Leishmania (L.) infantum. This study assessed the seasonality, spatiotemporal distribution, and climatic factors associated with L. longipalpis abundance in Araçatuba, São Paulo State, and detected Leishmania spp. DNA in captured females. Monthly collections were conducted from March 2023 to February 2024 in 72 households across eight urban areas using CDC-type light traps placed indoors and in peridomestic environments. A total of 1641 specimens (1516 males and 125 females) were captured, with 92.4% originating from peridomestic areas. Area 3 had the highest density (n = 671) and was the only area with PCR-positive females (n = 3). Vector activity peaked in December 2023 (n = 335). Male abundance differed significantly among peridomestic areas, particularly between Areas 3, 5, 6, and 7. In peridomestic areas, higher final temperatures increased vector abundance, whereas higher initial temperatures and humidity reduced it. Indoors, final temperature, humidity, and month were significant predictors. L. longipalpis exhibited a defined seasonal and spatial pattern influenced by climatic conditions. The detection of PCR-positive females (Area 3) highlights the epidemiological role of the vector and underscores the need for targeted interventions to control VL. Full article

Mosquitoes (Diptera: Culicidae) exhibit vertical stratification patterns in forest environments, a fundamental ecological aspect for understanding niche occupation patterns, host-seeking behavior, and consequently arbovirus transmission mechanisms. Despite the relevance of this topic, available studies mostly focus on genera such as Aedes, Haemagogus, and Sabethes which are traditionally associated with arbovirus transmission. There are still important gaps regarding stratification and seasonality in the Mansoniini tribe, whose biology and epidemiological role remain underexplored, especially in highly biodiverse ecosystems such as the Atlantic Forest. This study evaluated the influence of seasonality and vertical stratification on the mosquito community, with a detailed focus on the Mansoniini tribe, in an Atlantic Forest fragment in Brazil, between May 2023 and December 2024. Captures were performed monthly using CDC light traps positioned at 1.5 m and 10 m heights, and specimens were morphologically identified. A total of 880 mosquitoes from nine genera and 24 species were captured, of which 91 (10.3%) belonged to the Mansoniini tribe. The most abundant species were Coquillettidia fasciolata and Mansonia titillans, recorded in both strata. Our results indicate no marked vertical segregation for the studied mosquito community in this specific location, but a strong influence of seasonality, particularly for the Mansoniini tribe, reinforcing the role of meteorological data on the population structure of these species. These site-specific findings offer a foundational ecological portrait and a robust methodological template for a neglected taxon. They generate critical, testable hypotheses about niche partitioning in fragmented forests and underscore the necessity for broader spatial replication to disentangle the relative influence of seasonal versus vertical drivers in similar ecosystems. Full article

Visceral leishmaniasis (VL) is a serious vector-borne disease affecting humans and dogs, posing major public health challenges in endemic regions. Control efforts often target sandfly vectors, whose larvae and pupae develop in soil. Environmental management, such as removing organic matter, reducing moisture, and pruning vegetation, aims to limit breeding sites and reduce sandfly populations. This study evaluated the impact of integrated interventions on sandfly behavior in priority areas for VL control in Araçatuba, São Paulo, Brazil. The control strategy combined environmental management, canine surveys, and educational actions across seven local work areas (LWAs). Between 2019 and 2021, CDC-type light traps were installed in intra- and peridomiciliary settings at twelve properties in LWA 5. Spatial risk analysis for canine transmission was conducted in LWAs 3 and 5 using a Generalized Additive Model, with results presented as spatial odds ratios. Vector prevalence was analyzed using negative binomial regression compared to historical municipal data. Intervention coverage averaged 52.91% of visited properties (n = 15,905), ranging from 48% to 76.8% across LWAs. Adherence to environmental management exceeded 85%. Of the 150 sandflies collected, 98.67% were Lutzomyia longipalpis and 1.33% Nyssomyia neivai. A 6% reduction in vector density was observed compared with historical data, although this difference was not statistically significant. Spatial risk varied among LWAs, indicating heterogeneous transmission levels. These findings suggest that integrated environmental and educational interventions may contribute to reducing vector density and that identifying priority areas tends to support surveillance and the effectiveness of disease control actions. Full article

Zoological gardens represent unique sites for vector and vector-borne disease studies. They offer suitable breeding habitats for vector development and a diverse range of vertebrate hosts for blood feeding of insect vectors. This study aimed to assess the prevalence of avian blood parasites (Haemosporida, Trypanosomatida) in wild-caught mosquitoes (Culicidae) and Culicoides biting midges (Ceratopogonidae) from the largest and oldest zoo in Lithuania. Insects were collected in May–August 2023 using UV-light, CDC and BG-Sentinel traps; collected material was analysed using both microscopy and PCR-based methods for parasite detection. Overall, 504 parous biting midges (10 species) and 59 mosquitoes (three species) were investigated. Haemosporidians (Haemoproteus minutus (hTURDUS2), H. homogeneae (hSYAT16), and H. asymmetricus (hTUPHI01)) were identified in 5.4% of the 174 tested biting midges. Haemoproteus asymmetricus hTUPHI01 sporozoites were seen in only one individual of Culicoides kibunensis. Of 108 Culicoides females, 3.7% carried trypanosomatids—parasites infecting birds (Trypanosoma bennetti group) and mammals (T. theileri group). Among the 59 tested mosquitoes, two (3.4%) Cx. pipiens/torrentium mosquitoes were found to be PCR-positive for trypanosomatids (T. culicavium and Crithidia brevicula). No haemosporidian parasite DNA was detected in the mosquitoes examined. This pilot study indicates that avian blood parasites circulate within the Lithuanian Zoo, highlighting the need for further research on transmission pathways, vector–host interactions, and potential risks. Full article

Background: In recent decades, malaria vector species distribution and insecticide resistance have taken new colonization steps across Africa. Understanding the malaria vector insecticide resistance status, blood meal source, and species composition is of paramount importance in designing evidence-based vector control strategies. This study assessed the blood meal sources, sporozoite (infectivity) rate, and knockdown resistance allele’s frequency in female Anopheles arabiensis in chosen villages of Jabi Tehnan District, Northwest Ethiopia. Methods: The host-seeking and resting Anopheles gambiae s.l. were collected using human landing catches (HLCs), CDC light traps (CDC-LTs), pyrethrum spray catches (PSCs), and pit shelters (PSs) both indoors and outdoors. The analysis of both blood meal sources and circumsporozoite proteins was performed using enzyme-linked immunosorbent assay (ELISA). The detection of knockdown resistance gene mutations and species identification were conducted using a polymerase chain reaction (PCR). Results: A total of 5098 female Anopheles gambiae s.l. were collected. Of these, 1690 (33.2%) were collected from HLCs, 1423 (27.9%) from CDC light traps, 1635 (32.0%) from PSCs, and only 350 (6.9%) from pit shelters (PSs). Of these, 57.2% (n = 2915) female Anopheles mosquitoes were collected indoors using CDC light traps (CDC-LTs), human landing catches (HLCs), and pyrethrum spray catches (PSCs), while 38.2% (n = 2183) were collected outdoors using human landing collection (HLC), CDC light traps (CDC-LTs), and artificial pit shelters (PSs). Molecular identification to the species level showed that among the 530 An. gambiae s.l. samples analyzed using PCR, 96.03% (509) were An. arabiensis, and 3.97% (21) were unidentified species. The biting peak was found to be from 22:00 to 00:00 h for An. arabiensis. However, their activity decreased sharply after 23:00 to 00:00 h. The distribution of knockdown resistance genes in the tested specimens of An. arabiensis consisted of 1.4% (n = 3) heterozygous resistant (RS), 17.9% (n = 38) homozygous resistant (RR), and 80.7% (n = 171) homozygous susceptible (SS) genotypes. A higher proportion of Anopheles mosquitoes analyzed for blood meal analysis had a human blood meal origin at 13.1% (n = 47), followed by bovine at 8.9% (n = 32) and mixed at 5.8% (n = 21). Conclusions: The dominant malaria vector species was Anopheles arabiensis in the study area with a higher human blood meal origin. The Kdr gene was confirmed in the tested An. arabiensis, indicating that an alternative insecticide class should be used in the study area. Full article

The Amazon hosts one of the richest diversities of mosquitoes in the family Culicidae, which are key both as arbovirus vectors and as environmental bioindicators. However, the state of Amapá remains poorly studied regarding its mosquito fauna. This study aimed to characterize the diversity and seasonal composition of Culicidae in the municipality of Mazagão, Eastern Amazon, within a rural landscape influenced by human activity and extreme climatic events. Three sampling campaigns were conducted between 2023 and 2024, covering rainy, intermediary, and dry periods. Mosquitoes were collected using Protected Human Attraction (PHA) and CDC light traps at both ground and canopy strata. A total of 3500 specimens were obtained, representing 38 species across 15 genera. The intermediary period yielded the highest abundance and richness, whereas the dry season presented very low diversity, probably because of severe drought and forest fires. Dominant species included Coquillettidia (Rhy.) venezuelensis, Cq. albicosta, and Mansonia titillans. There were significant differences in community diversity between dry and wetter periods, underscoring the strong role of seasonality in shaping mosquito populations. These findings represent the entomofaunistic survey of the region, contributing to biodiversity knowledge and highlighting potential public health risks, thus reinforcing the need for continuous entomological monitoring. Full article

Malaria remains a significant public health challenge in Angola, particularly in Cuando Cubango province. This study aimed to characterize the local Anopheles mosquito population, evaluate the impact of indoor residual spraying (IRS) on key entomological indicators, and assess the community knowledge, attitudes, and practices (KAP) related to malaria and vector control. Mosquito collections were conducted indoors at three sites over five months using CDC light traps and Prokopack aspirators. Ten Anopheles species were identified, with An. funestus s.s. being the predominant vector, accounting for 91.7% of the Funestus group. The overall Plasmodium falciparum circumsporozoite protein (CSP) infection rate was 9.2%, with Makua exhibiting the highest rate (10.2%). Following IRS, the indoor resting density of the Funestus group decreased significantly in Makua and Agostinho Neto. In Makua, An. funestus s.s. CSP infection rates decreased by 55% following IRS implementation; however, this reduction was not statistically significant. Knockdown resistance mutations were detected in An. arabiensis and An. gambiae s.s. The 2020/2021 IRS campaign achieved 95% spray coverage and reached 421,856 individuals. Complementary KAP surveys with 647 households showed that 87% of respondents correctly identified mosquitoes as malaria vectors, 78% recognized key symptoms, and 89% supported continued IRS. Reported adherence to post-IRS precautions exceeded 70% and preference for IRS over ITN was expressed by most households. These findings highlight both biological and social dimensions of malaria control, demonstrating that vector control, community acceptance, and entomological surveillance are essential for effective and sustainable malaria interventions in Cuando Cubango. Full article

The Centers for Diseases Control (CDC) light trap is widely used for malaria vector surveillance, but its acquisition logistics pose challenges in Africa. Evaluating new traps can improve surveillance tools. This study compared the efficiency of the BG-Pro UV and Silver Bullet 2.1 UV (SB 2.1 UV) against the UV LED CDC trap in western Kenya’s rice irrigation area. The traps were tested indoors in eight houses over 64 nights. Light properties and fan speed were analyzed using spectrometry and an anemometer. The BG-Pro UV trap performed better than the UV LED CDC trap for An. gambiae s.l. (RR 2.0, 95% CI 0.9–3.9) and An. funestus s.l. (RR 3.5, 95% CI 1.9–6.4). The SB 2.1 UV trap was more effective in capturing An. gambiae s.l. (RR 4.3, 95% CI 2.5–7.3) and An. funestus s.l. (RR 7.1, 95% CI 3.9–13.1), and also caught three times more Culex spp. (RR 2.7, 95% CI 1.2–6.0). SB 2.1 UV had the highest downstream force, and all traps emitting UV-A light had consistent wavelengths. Overall, the BG-Pro and SB 2.1 traps’ trapping efficiency was three to six times more than the CDC trap, making them promising surveillance tools, particularly in low-density malaria settings. Full article

Leishmaniasis is a zoonotic disease caused by protozoa of the genus Leishmania, transmitted by phlebotomine sand flies. Understanding the feeding behavior and infection rates of these vectors is crucial for disease surveillance and control. We aimed to investigate the natural infection rate of Leishmania spp. in phlebotomines and analyze their blood-feeding patterns in one of the priority areas of the state of São Paulo for the implementation of insecticide-impregnated dog collars. Sand flies were collected from urban and peri-urban areas between 2022 and 2024 using CDC light traps, manual aspiration, and Shannon traps. PCR was used to detect Leishmania DNA (SSU rDNA gene), and blood meal sources (COI gene). A total of 414 sand flies were collected, with 222 engorged females analyzed for blood meals and 192 specimens tested for Leishmania spp. infection. The predominant blood source was humans (67%), followed by chickens (64.1%), and dogs (18.9%), considering that 45.1% of the samples presented mixed blood meals. Leishmania infantum was found in 1% of the samples. These findings highlight the feeding plasticity of sand flies and their potential role in disease transmission, reinforcing the need for continuous epidemiological surveillance and vector control strategies, particularly the implementation of insecticide-impregnated dog collars. Full article

Assessing bloodmeal sources and sporozoite infection rates in mosquito vectors is essential for understanding their role in malaria transmission. This study investigated these factors in Hawassa, Southern Ethiopia—an area recently invaded by Anopheles stephensi—through adult mosquito collections conducted between January and April 2023 using BG-Pro traps, CDC Light Traps, and Prokopack Aspirators. A total of 738 female Anopheles mosquitoes were collected, including An. arabiensis (72.9%), An. pharoensis (13.4%), An. stephensi (7.5%), and An. coustani (6.2%). Human Blood Index (HBI) values were 23.3% for An. arabiensis, 43.8% for An. pharoensis, 8.3% for An. stephensi, and 25.0% for An. coustani. Plasmodium infection was detected in 8% of An. arabiensis and 4.7% of An. pharoensis, while An. stephensi and An. coustani were uninfected. The findings highlight the presence of multiple competent malaria vectors, with significant infection rates observed in both primary and secondary species, underscoring the need to include secondary vectors in control and surveillance programs. The detection of An. stephensi alongside native vectors adds complexity to malaria control efforts, reinforcing the importance of continuous monitoring to understand the changing dynamics of vector populations and their roles in transmission. Full article

Background: Malaria is a severe health problem in native communities of Condorcanqui in the Amazonas region of Peru. Recently, the number of malaria cases has increased considerably following a Plasmodium falciparum outbreak in 2019. However, there is no information on the anophelines acting as Plasmodium vectors in this area. This study aimed to identify Anopheles species circulating in previously unexplored native communities of Condorcanqui. Additionally, we sought to detect the presence of DNA from P. vivax and P. falciparum parasites in mosquitoes. Methods: During three exploratory visits between March and September 2022, 453 mosquitoes were collected using Shannon traps and CDC light traps. Only specimens morphologically identified as Anopheles sp. were subjected to molecular confirmation through PCR amplification and sequencing of the Cox1 barcode region. Plasmodium parasites were detected using nested PCR targeting of the 18S rRNA subunit, while human blood meal feeding was evaluated using a human β-globin marker. Results: A total of 66 specimens were molecularly confirmed as anopheline species: An. benarrochi B, An. triannulatus, An. Costai, and An. nimbus. Six specimens of An. benarrochi B were exclusively positive for Plasmodium parasites by PCR. Moreover, four specimens tested positive for Plasmodium and the presence of human blood, suggesting the anthropophilic behavior of An. benarrochi B and its possible role as a potential malaria vector in this area. Conclusions: In conclusion, while this study provides valuable insights into the potential role of Anopheles benarrochi as a malaria vector in Amazonas, further research is essential to fully understand its behavior and transmission dynamics in the region. Full article

The assessment of mosquito diversity in remnants of the Atlantic Forest, which are considered biodiversity hotspots, is crucial for studying patterns of behavior and adaptation, performing environmental monitoring, and public health. These studies provide valuable insights into the ecology and biology of these insects, contributing to a better understanding of forest ecosystems and the interactions among the species that inhabit them. The present study aimed to assess the variation in faunistic parameters of abundance, richness, diversity, and evenness along an environmental gradient. This gradient extends from the edge toward the interior of the fragment. The research tested the hypothesis that edge effects influence the distribution of mosquito species in the Tijuca National Park. Sampling was carried out from May 2022 to December 2023, occurring monthly over two consecutive days within the park area. Three different sampling points within the conservation unit were selected: sampling point 1, forest edge; sampling point 2, 35 m from the edge; and sampling point 3, 500 m from the edge, representing different distance gradients. Mosquitoes were captured using CDC light traps with CO₂, Shannon traps, and human-protected attraction; the combination of these traps provided a representative sampling of the diversity of adult mosquitoes present in the study area. An active search for immatures was performed in larval habitats using pipettes and entomological scoops. During the sampling period, a total of 1004 specimens were collected, comprising 320 immatures and 684 adults, representing 27 species. Statistical analyses showed that abundance and richness along the established gradient were not uniform among the sampling points. The Kruskal–Wallis test identified two distinct sampling points: the forest edge (point 1) and a location 35 m from the edge (point 2). The sampling point at the forest edge exhibited the highest levels of species richness, diversity, and evenness. However, given the brief duration of this study, it is crucial to expand the sampling efforts by increasing both the number and frequency of traps and collections. Such enhancements are essential to achieve a more thorough understanding of the ecological patterns and processes at play. Full article

Indoor residual spraying (IRS) and the use of insecticide-treated bednets for malaria vector control have contributed substantially to a reduction in malaria disease burden. However, these control tools have important shortcomings including being donor-dependent, expensive, and often failing because of insufficient uptake. We assessed the safety and efficacy of a user-friendly, locally tailored malaria vector control approach dubbed “Hut Decoration for Malaria Control” (HD4MC) based on the incorporation of a WHO-approved insecticide, Actellic^® 300 CS, into a customary hut decoration practice in rural Uganda where millions of the most vulnerable and malaria-prone populations live in mud-walled huts. Three hundred sixty households were randomly assigned to either the HD4MC (120 households), IRS (120 households) or control group without any wall treatment (120 households). Entomological indices were assessed using pyrethrum spray catching, CDC light traps and human landing catches. The Actellic^® 300 CS toxicity on acetylcholinesterase activity among applicators of HD4MC was evaluated using the Test-mate (Model 400) erythrocyte acetylcholinesterase (AChE) test V.2, whereas toxicity in household occupants was monitored clinically. The Actellic^® 300 CS level in house dust was analyzed using reversed-phase high-performance liquid chromatography (RP-HPLC). Entomological indices were compared between the three study arms at 1.5, 3 and 6 months post-intervention. HD4MC- and IRS-treated huts had a significantly reduced malaria vector density and feeding rate compared to control huts. There was no significant reduction in acetylcholinesterase activity at 1.5 and 24 h post exposure. Actellic^® 300 CS exposure did not result in any serious adverse events among the household occupants. In conclusion, HD4MC was safe and had comparable efficacy to canonical IRS. Full article