Chagas disease is one of the most important vector-borne diseases in Latin America. Instituting home improvement preventive measures and increasing health education contribute to successful control of the triatomine inse...Chagas disease is one of the most important vector-borne diseases in Latin America. Instituting home improvement preventive measures and increasing health education contribute to successful control of the triatomine insect vector. The impact of home and road improvements and health education upon the inhabitants of 37 human dwellings in three small towns in western Mexico were studied. Initially, few house roofs were made of concrete and few walls were cement-lined. Almost all houses initially lacked metal window screens and none used barbed wire fences. One year after the intervention, all of these measures were more common, and almost 100% of houses continued to use window screens and barbed wire fences ten years post-intervention. By ten years post-intervention, >75% of houses had cement-lined walls. Initially, 24.3% of human dwellings were infested with Usinger; at one and ten years post-intervention, only 2.7% of dwellings were infested. The abundance of peridomestic opossums decreased after intervention and remained low ten years later. Approximately 10% of dogs were infected in both surveys. Human infections decreased from 2.98% to zero by 13 years post-intervention. Implementation of these intervention measures led to the successful control of Chagas transmission in these towns.
Successful surveillance and control of mosquito arbovirus vectors requires effective and sensitive trapping methods for adult insects. The Biogents Sentinel (BGS) trap is widely used for mosquito trapping but has low cap...Successful surveillance and control of mosquito arbovirus vectors requires effective and sensitive trapping methods for adult insects. The Biogents Sentinel (BGS) trap is widely used for mosquito trapping but has low capture efficiency for both female and male under semi-field conditions. Efficiency refers to the proportion of mosquitoes that are trapped of those encountering the trap. We verified the efficiency of the BGS under field conditions in suburban Riverside, California, U.S.A., following our previous work determining the efficiency under semi-field conditions in Cairns, Northern Australia. The efficiency of the BGS with CO and a human skin odor mimic (BG-Lure) for both sexes in the field was 9%. This closely aligns with the results of our previous study, the efficiency for females being 5% and males being 9%. In the present study microclimatic conditions were monitored and capture occurred during periods of significantly lower mean temperature. There were no discernible changes in wind directionality or strength in the 60 s leading up to mosquito capture by the BGS. Our results support our previous findings that capture efficiency of the BGS for is low.
Mosquitoes affect human health and well-being globally through their roles as disease-causing pathogen vectors. Utilizing genetic techniques, we conducted a large-scale dietary study of three bat species common to the so...Mosquitoes affect human health and well-being globally through their roles as disease-causing pathogen vectors. Utilizing genetic techniques, we conducted a large-scale dietary study of three bat species common to the southeastern U.S.A., (Seminole bat) (evening bat), and (southeastern myotis). Through next-generation sequencing of a 180 bp portion of cytochrome oxidase subunit I (COI) of mitochondrial DNA from 180 bat guano samples, we documented consumption of 17 species of mosquitoes by bats, including six endemic arbovirus vectors. , , , , , and were consumed by 51.3%, 43.7%, 27.2%, 22.8%, 18.0%, and 12.7% of bats sampled, respectively. Consumption of two of these mosquito species was explained by spatial variables reflecting the prevalence of mosquito larval habitat, five were explained by bat traits (bat mass, bat species), and two were explained by these factors plus temporal variables (maximum daily temperature, time since sunset, date), making it challenging to offer specific guidance on how best to promote bats as a means of reducing arbovirus vector species. Our results show that common bat species of the southeastern U.S.A. consume endemic, but not exotic, arbovirus mosquito vectors. Future studies are needed to understand the impact of bat consumption on mosquito numbers and public health.
The study assessed the distribution of Malaysian adults associated with detection in low-rise residential areas using a modified sticky ovitrap (MSO). The relationship between and climatological parameters were also d...The study assessed the distribution of Malaysian adults associated with detection in low-rise residential areas using a modified sticky ovitrap (MSO). The relationship between and climatological parameters were also determined. Fifty-two weeks of surveillance using 273 MSOs were conducted in four installation areas of eleven sampling sites. Specimens were subjected to PCR using specific primers for detection. The relationship between climatological parameters and captured were analyzed using Spearman rank correlation coefficient test. The majority of were captured in residential houses (87%), followed by playgrounds or parks (11.5%), guardhouses (1%), and community halls (0.5%). Most of the specimens (92%) were superinfected with AlbA and AlbB strains. A positive correlation with no significant association was found for rainfall ( = 0.015, P = 0.072), relative humidity ( = 0.005, P = 0.526), minimum temperature ( = 0.005, P = 0.516), and mean temperature ( = 0.003, P = 0.689). MSO effectively captured a high number of that was determined to be the predominant mosquito species found in low-rise residential areas. The adult collection is not only influenced by climatological parameters but also by other factors, including environmental conditions and general sanitation status.
Ticks are known vectors of several viral, bacterial, and protozoal pathogens that cause disease in both humans and animals. While pathogen prevalence has been studied extensively in other portions of the United States, p...Ticks are known vectors of several viral, bacterial, and protozoal pathogens that cause disease in both humans and animals. While pathogen prevalence has been studied extensively in other portions of the United States, pathogen surveillance studies within tick populations in the central Appalachian region of Virginia is almost nonexistent. Two prominent species in this region are (the blacklegged tick) and (the lone star tick). In this study, we collected ticks biweekly from three habitat types (forest, urban, and pasture) across eight counties in southwest Virginia from June, 2019-November, 2020. and captures were screened for evidence of associated tick-borne pathogens. In this region, sensu stricto (15.3% in nymphs and 37.6% in (2.97% in nymphs and 2.33% in adults) were detected in ticks. Aside from two previously reported Powassan-positive ticks from Floyd County, VA, no additional Powassan-positive ticks are reported here. No evidence of Heartland virus (HRTV), or Bourbon virus (BRBV) was detected in collected Detection and confirmation of multiple emerging tick-borne pathogens in this region raises an increased concern for public health risk, calling for heightened awareness of tick-borne pathogen transmission and increased tick surveillance in understudied areas.
The last statewide survey of hard ticks in Alabama was in 1972. To address this deficit, we examined the distribution of the medically important species across the state, (Say), (Say), (L.), and (Koch), between April...The last statewide survey of hard ticks in Alabama was in 1972. To address this deficit, we examined the distribution of the medically important species across the state, (Say), (Say), (L.), and (Koch), between April, 2018 and February, 2021. Collections primarily involved dragging (April to July) and examination of harvested deer (November to February). A total of 2,927 ticks was collected from 110 sites; three species, and , represented 91.70% of all ticks collected. and were the most common species encountered in drags; dominated deer collections. was never found on deer, whereas was only found on deer. Stepwise regression (AIC) of drag data was linked to several site variables. Results suggest a linear response along a south (low abundance) to north (high abundance) gradient, in addition to increased abundance at sites with lower temperatures and greater precipitation and canopy cover.
Prior research on baiting and feeding of wildlife found changes in habitat and the concentration of wildlife on a local scale (e.g., hundreds of meters). Since changes in habitat and host density affect ticks, feeding wi...Prior research on baiting and feeding of wildlife found changes in habitat and the concentration of wildlife on a local scale (e.g., hundreds of meters). Since changes in habitat and host density affect ticks, feeding wildlife may lead to changes in tick and tick-borne disease ecology. We quantified the effect of feeding deer on ticks and tick-borne diseases at 79 pairs of sites with and without deer feeders during May-August of 2019 and 2020. We captured 0.4 fewer adult (p<0.05) and 1.2 fewer nymphal ticks (p=0.01) at feeder sites. This effect intensified over time with one fewer tick trapped at old feeders (≥5 years) compared to new feeders (<5 years, p<0.05). Greater daily wildlife visitation rates (p<0.001) may have allowed questing ticks to encounter hosts more readily. Most collected ticks were (92.8%), a vector of and pathogens, though prevalence of these pathogens did not differ (p>0.13) at a local scale. Supplemental deer feeding appears to influence ticks, possibly due to decreased tick habitat and increased wildlife use around feeders. Our findings indicate feeding does not lead to increased prevalence of or bacteria within locally.
Rock lizards of the genus are interesting research models due to their asexual reproduction. Ectoparasitic mites and ticks of these lizards are poorly known, despite some of these chelicerates being vector pathogens of...Rock lizards of the genus are interesting research models due to their asexual reproduction. Ectoparasitic mites and ticks of these lizards are poorly known, despite some of these chelicerates being vector pathogens of humans and wildlife. Here we document and curate previously known data on ectoparasitic Acari of rock lizards and, based on our extensive survey, provide an annotated list of these ectoparasitic arthropods (six tick species, one macronyssid species, and seven chigger species). We also provide new host records ( on , , , and ; on ; on ); and new geographical records ( in Russia and Georgia).
Localized cutaneous leishmaniasis (LCL) is endemic in the Yucatan Peninsula, with historical and contemporary records mainly in the states of Campeche and Quintana Roo. Recently, we reported autochthonous LCL cases and 2...Localized cutaneous leishmaniasis (LCL) is endemic in the Yucatan Peninsula, with historical and contemporary records mainly in the states of Campeche and Quintana Roo. Recently, we reported autochthonous LCL cases and 27.6% of asymptomatic infection in the municipality of Tinum, Yucatan, where no studies of Phlebotominae (Diptera: Psychodidae) sand flies have been carried out. In this work, from November, 2019 to February, 2020, we conducted a field study in three areas of Tinum to document, for the first time, the species of Phlebotominae in areas with records of human leishmaniasis transmission. In order of abundance, the species identified were , , and . Most of the sand flies were captured in a Shannon trap where 77.8% of collected specimens were females. The distribution of sand fly species showed some degree of heterogeneity among sites, and the highest species richness was registered in a site located in Xcalakoop. We also discuss the medical importance of , and as potential vectors of causal agents of LCL in this area
The biological effect of acetone extracts from three selected plants, and on the egg hatch rate, larvicidal activity, and larval development of L. was investigated. The egg hatch rate of was significantly reduced (P<...The biological effect of acetone extracts from three selected plants, and on the egg hatch rate, larvicidal activity, and larval development of L. was investigated. The egg hatch rate of was significantly reduced (P<0.01) when the extracts of were used. Moreover, the used extracts significantly exhibited a variable larvicidal activity against the (P<0.001). The most toxicity was observed when the larvae were treated with the acetonic extract of showing different toxicities with lower LCs at 140.1 ppm after two days and 51.3 ppm after ten days. In this observed time, larvae suffered chronic toxicities (increased mortality with increasing exposure time and sublethal endpoints, such as decreased larvae development) when treated with used plant extracts, leading to 96.7% mortality with and 91.5% and 85.7% mortalities with and , respectively. All concentrations significantly obstructed larvae development, causing significant reductions in both the proportion of pupation (P<0.001) and the emergence of adults (P<.001). The larval development reduction was observed under the extracts treatment, where only 15.2% and 9.7% of the larvae managed to reach pupal and adult stages, respectively. In conclusion, applying acetone extracts from to immature mosquito breeding sites may efficiently control mosquitoes to reduce the reliance on insecticides against these disease vectors.
Although Lyme disease is currently classified as exotic in Mexico, recent studies have suggested that it might be endemic there. We assessed the potential risk for the establishment of transmission in Mexico. To identif...Although Lyme disease is currently classified as exotic in Mexico, recent studies have suggested that it might be endemic there. We assessed the potential risk for the establishment of transmission in Mexico. To identify the potential routes of spread, Complex Inference Networks were used initially to identify potential vector-host interactions between hard ticks () and migratory birds in the U.S., and a model for predicting the most important potential bird hosts of hard ticks was then obtained. By using network metrics, -vectors were identified as those species with highest connectivity within and between network communities and had the potential to keep the pathogen circulating with many birds and to be dispersed to several regions. The climatic profile where these interactions occur in the U.S. was characterized and a geographic model for each -vector was built. The accuracy of these models to predict areas where hard ticks have been reported positive for allows one to identify areas of greater risk of Lyme disease emergence. These hard tick-bird interactions and their climatic profile were mapped into the winter ranges of birds in Mexico. Thus, those regions in Mexico with the highest potential for becoming endemic areas of Lyme disease through the arrival of hard ticks and birds infected by were identified These areas are candidates for future surveillance programs
Predator-prey interactions can have a significant impact on the abundance and distribution of species, but the outcome of these interactions is often context-dependent. In small freshwater habitats, predacious copepods a...Predator-prey interactions can have a significant impact on the abundance and distribution of species, but the outcome of these interactions is often context-dependent. In small freshwater habitats, predacious copepods are potential biological control agents for mosquito larvae. Through laboratory experiments, we tested if the presence of a non-mosquito prey (neonate influenced prey selection of the predaceous copepod () on 1 instar mosquitoes ( and ). Copepods were starved for 12 h prior to being exposed to the two prey types (larval mosquitoes and at three densities: 25 mosquitoes:75 , 50 mosquitoes:50 , 75 mosquitoes:25 . Single prey choice trials for each species as well as no-predator trials were also established for controls. Copepods were effective predators, with a single copepod consuming up to 37 1 instar mosquito larvae during the 24-h trials. The number of mosquitoes consumed increased with their relative density, but the proportion of mosquitoes consumed was highest when made up only 25% of the population. Results from our study show that in a simple predator/two-prey system, two species of larval mosquitoes ( and ) are preferentially consumed over an alternative zooplankton by the copepod predator
Monitoring mosquito populations is crucial for vector-borne disease surveillance. Routine mosquito surveillance in many regions of the United States is performed either by vector abatement districts or public health depa...Monitoring mosquito populations is crucial for vector-borne disease surveillance. Routine mosquito surveillance in many regions of the United States is performed either by vector abatement districts or public health departments. These surveillance programs often use multiple trap types and attractants to target key mosquito species, however setting different traps with varying attractants can be expensive and labor intensive. Because funding for mosquito control is highly variable throughout the U.S., some programs may be limited in their surveillance capabilities. To determine whether a single trap-attractant combination could provide specificity for key vector and nuisance species, as well as sensitivity for rare species, we compared the BG-Sentinel 2 and CDC miniature light traps paired with CO, UV-LED, BG Lure, BG Sweetscent, octenol, or chicken feathers. Trapping was conducted biweekly from June/July-October 2019 and 2020 in Montgomery and Prince George's County, MD. BG traps collected significantly more than CDC traps when paired with BG Lure, Sweetscent, or octenol. BG/CO traps collected both the greatest number of total mosquitoes and . BG/CO, CDC/CO, and CDC/UV traps provided the most diverse collections. Trapping with the CO-baited BG-Sentinel is recommended as an effective strategy for general mosquito surveillance when resources are limited.
Studies of the biodiversity of mosquito larval habitats are important for vector-borne disease control programs and help to improve vector distribution maps. This study was designed to investigate the geographical distri...Studies of the biodiversity of mosquito larval habitats are important for vector-borne disease control programs and help to improve vector distribution maps. This study was designed to investigate the geographical distribution of mosquito species and their larval habitats in urban, rural, and natural areas in northern Spain. Pre-imaginal stages were collected over two sampling periods (spring and summer) in 2019. In the laboratory, immature specimens were reared to the adult stage for species identification by morphological taxonomy and/or molecular methods. In total, 2,182 specimens belonging to 13 different native mosquito species of five genera were collected from 135 sampling points of which 59.2% harbored larvae. s.l. was the most abundant species (45.1%), followed by (12.3%), s.l. (10.2%), (9.5%), and nine other species with lower frequencies that accounted for less than 25%. By molecular identification, s.s. was identified as the only species within the species complex and as the predominant subspecies of the species complex. Margins in large sunlit water bodies were the most suitable sites for s.l., whereas s.l. was present in both natural and artificial habitats. The larval site index, species richness, and relative abundance of the mosquitoes were determined based on the characteristics of the sites where they were collected. The public health importance and ecology of some identified mosquitoes is also discussed.
Predators and their interactions with target prey influence the efficiency of control strategies. In the present study, we demonstrate the implementation of natural predator selection for controlling dengue vectors in no...Predators and their interactions with target prey influence the efficiency of control strategies. In the present study, we demonstrate the implementation of natural predator selection for controlling dengue vectors in northern Vietnam through field-based observation of aquatic insect predators in natural habitats and lab-based assessment of predatorial capacities for several aquatic insect predators. The selected species was then used to evaluate the predatory-prey interaction using functional responses (FRs) toward 3- and 4-instar larvae of four major medical mosquito species (, and ). The preference of selected predators for larvae over other mosquito larvae was also investigated. Both field observation and lab experiments indicated that the giant water bug was abundant and exhibited the highest predatory capacity for mosquito larvae. The predator exhibited type II FRs when offered each of the four prey species, and the greatest attack rates were observed for and , with only negligible differences observed in the handling times of the prey species. Further, Manly's selectivity (α) values calculated from the prey choice experiments showed that was preferred over both and . Together, these findings indicate that could be successfully used to facilitate the biological control of both and within the species' distributional overlap in Southeast Asia.
Packard, the groundhog tick or woodchuck tick, is the main known vector of Powassan virus (POWV) disease in North America and an ectoparasite that infests diverse small- and mid-size mammals for blood meals to complete i...Packard, the groundhog tick or woodchuck tick, is the main known vector of Powassan virus (POWV) disease in North America and an ectoparasite that infests diverse small- and mid-size mammals for blood meals to complete its life stages. Since spends much of its life cycle off the host and needs hosts for a blood meal in order to pass to the next life stage, it is susceptible to changes in environmental conditions. We used a maximum-entropy approach to ecological niche modeling that incorporates detailed model-selection routes to link occurrence data to climatic variables to assess the potential geographic distribution of under current and likely future climate conditions. Our models identified suitable areas in the eastern United States, from Tennessee and North Carolina north to southern Canada, including Nova Scotia, New Brunswick, eastern Newfoundland and Labrador, southern Quebec, and Ontario; suitable areas were also in western states, including Washington and Oregon and restricted areas of northern Idaho, northwestern Montana, and adjacent British Columbia, in Canada. This study produces the first maps of the potential geographic distribution of . Documented POWV cases overlapped with suitable areas in the northeastern states; however, the presence of this disease in areas classified by our models as not suitable by our models but with POWV cases (Minnesota and North Dakota) requires more study.