Search results for "anopheles"
showing 10 items of 29 documents
The Population Genomics of Anopheles gambiae Species Complex: Progress and Prospects
2021
Anopheles gambiae sensu lato is a species complex containing principal malaria vectors such as An. gambiae sensu stricto, An. coluzzii, and An. arabiensis. Numerous studies have shown dynamic species hybridization among member of this complex makes them an ideal model for studying evolution and speciation as well as for applied vector biology. Applying a population genomics approach to the An. gambiae and An. coluzzii species group has led to a number of important and epidemiologically relevant insights including: (1) organization of genomic divergence into “islands of speciation”; (2) competing models of population origin of An. gambiae and An. Coluzzii; (3) description of asymmetric intro…
Risk estimation for air travel-induced malaria transmission in central Europe – A mathematical modelling study
2019
Abstract Background Aim of our study was to identify conditions under which malaria transmission caused by imported infectious mosquitoes or travellers could occur at large central European airports, and if such transmission could be sustained by indigenous mosquitoes. Methods We developed a deterministic and a stochastic compartmental Susceptible-Exposed-Infectious-Recovered-Susceptible (humans)/Susceptible-Exposed-Infectious (mosquitoes) model with two mosquito (imported Anopheles gambiae, indigenous A. plumbeus) and three human (travellers, airport personnel exposed/not exposed to imported A. gambiae) populations. We assessed various scenarios to identify combinations of model parameters…
Proposed use of spatial mortality assessments as part of the pesticide evaluation scheme for vector control
2013
Background: The WHO Pesticide Evaluation Scheme to evaluate the efficacy of insecticides does not include the testing of a lethal effect at a distance. A tool was developed to evaluate the spatial mortality of an insecticide product against adult mosquitoes at a distance under laboratory and field conditions. Operational implications are discussed. Methods: Insecticide paint, Inesfly 5A IGR (TM), containing two organophosphates (OPs): chlorpyrifos and diazinon, and one insect growth regulator (IGR): pyriproxyfen, was the product tested. Laboratory tests were performed using "distance boxes" with surfaces treated with one layer of control or insecticide paint at a dose of 1 kg/6 sq m. Field …
Vertical transmission of naturally occurring Bunyamwera and insect-specific flavivirus infections in mosquitoes from islands and mainland shores of L…
2018
Background Many arboviruses transmitted by mosquitoes have been implicated as causative agents of both human and animal illnesses in East Africa. Although epidemics of arboviral emerging infectious diseases have risen in frequency in recent years, the extent to which mosquitoes maintain pathogens in circulation during inter-epidemic periods is still poorly understood. This study aimed to investigate whether arboviruses may be maintained by vertical transmission via immature life stages of different mosquito vector species. Methodology We collected immature mosquitoes (egg, larva, pupa) on the shores and islands of Lake Baringo and Lake Victoria in western Kenya and reared them to adults. Mo…
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2014
Malaria is still a primary health problem in Colombia. The locality of Tierradentro is situated in the municipality of Montelibano, Cordoba, in the northwest of Colombia, and has one of the highest annual parasite index of malaria nationwide. However, the vectors involved in malaria transmission in this locality have not yet been identified. In this study, the local anthropophilic Anopheles composition and natural infectivity with Plasmodium were investigated. In August 2009, 927 female Anopheles mosquitoes were collected in eight localities using the human landing catch method and identified based on their morphology. Cryptic species were determined by restriction fragment length polymorph…
Genetic and phenotypic variation of the malaria vector Anopheles atroparvus in southern Europe
2011
Abstract Background There is a growing concern that global climate change will affect the potential for pathogen transmission by insect species that are vectors of human diseases. One of these species is the former European malaria vector, Anopheles atroparvus. Levels of population differentiation of An. atroparvus from southern Europe were characterized as a first attempt to elucidate patterns of population structure of this former malaria vector. Results are discussed in light of a hypothetical situation of re-establishment of malaria transmission. Methods Genetic and phenotypic variation was analysed in nine mosquito samples collected from five European countries, using eight microsatell…
Efficacy of an insecticide paint against malaria vectors and nuisance in West Africa--part 2: field evaluation.
2010
Abstract Background Widespread resistance of the main malaria vector Anopheles gambiae to pyrethroids reported in many African countries and operational drawbacks to current IRS methods suggest the convenience of exploring new products and approaches for vector control. Insecticide paint Inesfly 5A IGR™, containing two organophosphates (OPs), chlorpyrifos and diazinon, and one insect growth regulator (IGR), pyriproxyfen, was tested in Benin, West Africa, for 12 months. Methods Field trials were conducted in six experimental huts that were randomly allocated to one or two layers of insecticide at 1 Kg/6 m2 or control. Evaluations included: (i) early mosquito collection, (ii) mosquito release…
Primera cita de Culex interrogator (Diptera: Culicidae) para la Hispaniola y actualización del listado de mosquitos de Jarabacoa, República Dominicana
2020
Desde que dio inicio el nuevo siglo, varios estudios sobre la culicidofauna de la Hispaniola han elevado el conocimiento de este grupo de artrópodos, muy relevantes desde el punto de vista médico y veterinario. En relación a la diversidad de la familia Culicidae, los hallazgos más recientes se han realizado en el municipio de Jarabacoa, República Dominicana. Con el objetivo de profundizar en la diversidad de los culícidos presentes en esta localidad montañosa de El Cibao, se procedió a la búsqueda de criaderos de mosquitos, sobre todo de origen natural, desde enero de 2018 hasta junio de 2019. La identificación de los especímenes se realizó mediante la utilización de lupa binocular y micros…
X-Ray induced sterility, dominant lethality and inherited semisterility in Anopheles pharoensis Theo (Dipt., Culicidae)
2009
Males 3-days old of the mosquito Anopheles pharoensis were x-irradiated with doses from 500 till 5000 r at a dose rate of 108 r/min and crossed immediately after irradiation with untreated virgin females. Sterility was calculated in the first three successive egg batches. Dose response was represented by a linear sterility curve with rapid increase in lower doses. The percent of induced dominant lethality was shown mainly in the egg stage of the offspring by a lethality curve almost parallel to the sterility one. The hatched larvae were reared to F 1 adults. All individuals of F 1 resulting from doses 1, 2 and 3 kr were back crossed to the other sex, mass mated for three days and the female…
Efficacy of an insecticide paint against insecticide-susceptible and resistant mosquitoes - Part 1: Laboratory evaluation
2010
Abstract Background The main malaria vector Anopheles gambiae and the urban pest nuisance Culex quinquefasciatus are increasingly resistant to pyrethroids in many African countries. There is a need for new products and strategies. Insecticide paint Inesfly 5A IGR™, containing two organophosphates (OPs), chlorpyrifos and diazinon, and insect growth regulator (IGR), pyriproxyfen, was tested under laboratory conditions for 12 months following WHOPES Phase I procedures. Methods Mosquitoes used were laboratory strains of Cx. quinquefasciatus susceptible and resistant to OPs. The paint was applied at two different doses (1 kg/6 m2 and 1 kg/12 m2) on different commonly used surfaces: porous (cemen…