Insecticide resistance is a significant challenge facing the successful control of mosquito vectors globally. Bioassays are currently the only method for phenotyping resistance. They require large numbers of mosquitoes for testing, the availability of a susceptible comparator strain, and often insectary facilities.
View Article and Find Full Text PDFArboviruses including dengue, Zika, and chikungunya are amongst the most significant public health concerns worldwide. Arbovirus control relies on the use of insecticides to control the vector mosquito Aedes aegypti (Linnaeus), the success of which is threatened by widespread insecticide resistance. The work presented here profiled the gene expression of Ae.
View Article and Find Full Text PDFDengue, Zika and chikungunya are diseases of global health significance caused by arboviruses and transmitted by the mosquito Aedes aegypti, which is of worldwide circulation. The arrival of the Zika and chikungunya viruses to South America increased the complexity of transmission and morbidity caused by these viruses co-circulating in the same vector mosquito species. Here we present an integrated analysis of the reported arbovirus cases between 2007 and 2017 and local climate and socio-economic profiles of three distinct Colombian municipalities (Bello, Cúcuta and Moniquirá).
View Article and Find Full Text PDFFused filament fabrication (FFF) 3D printers are increasingly used in industrial, academic, military, and residential sectors, yet their emissions and associated user exposure scenarios are not fully described. Characterization of potential user exposure and environmental releases requires robust investigation. During operation, common FFF 3D printers emit varying amounts of ultrafine particles (UFPs) depending upon feedstock material and operation procedures.
View Article and Find Full Text PDFInt J Environ Res Public Health
July 2020
The United Kingdom (UK) has reported a single detection of the eggs of the invasive mosquito vector in each of the three years from 2016 to 2018, all in southeast England. Here, we report the detection of mosquito eggs on three occasions at two sites in London and southeast England in September 2019. Mosquito traps were deployed at 56 sites, in England, Scotland, Wales, and Northern Ireland, as part of a coordinated surveillance programme with local authorities, Edge Hill University, and government departments.
View Article and Find Full Text PDFBackground: The international movement of used tyres is a major factor responsible for global introductions of Aedes invasive mosquitoes (AIMs) (Diptera: Culicidae) that are major disease vectors (e.g. dengue, Zika, chikungunya and yellow fever).
View Article and Find Full Text PDFMosquito-borne diseases resulting from the expansion of two key vectors, Aedes aegypti and Aedes albopictus (Diptera: Culicidae), continue to challenge whole regions and continents around the globe. In recent years there have been human cases of disease associated with Chikungunya, dengue and Zika viruses. In Europe, the expansion of Ae.
View Article and Find Full Text PDFResistance to pyrethroids in mosquitoes is mainly caused by target site insensitivity known as knockdown resistance (). In this work, we examined the point mutations present in portions of domains I, II, III, and IV of the sodium channel gene in mosquitoes from three Colombian municipalities. A partial region coding for the sodium channel gene from resistant mosquitoes was sequenced, and a simple allele-specific PCR-based assay (AS-PCR) was used to analyze mutations at the population level.
View Article and Find Full Text PDFBackground: Aedes aegypti is a cosmopolite mosquito, vector of arboviruses. The worldwide studies of its insecticide resistance have demonstrated a strong loss of susceptibility to pyrethroids, the major class of insecticide used for vector control. French overseas territories such as French Guiana (South America), Guadeloupe islands (Lesser Antilles) as well as New Caledonia (Pacific Ocean), have encountered such resistance.
View Article and Find Full Text PDFBackground: There has been rapid scale-up of malaria vector control in the last ten years. Both of the primary control strategies, long-lasting pyrethroid treated nets and indoor residual spraying, rely on the use of a limited number of insecticides. Insecticide resistance, as measured by bioassay, has rapidly increased in prevalence and has come to the forefront as an issue that needs to be addressed to maintain the sustainability of malaria control and the drive to elimination.
View Article and Find Full Text PDFBackground: Pyrethroid insecticide-treated bed nets (ITNs) help contribute to reducing malaria deaths in Africa, but their efficacy is threatened by insecticide resistance in some malaria mosquito vectors. We therefore assessed the evidence that resistance is attenuating the effect of ITNs on entomological outcomes.
Methods And Findings: We included laboratory and field studies of African malaria vectors that measured resistance at the time of the study and used World Health Organization-recommended impregnation regimens.
The mosquito Aedes aegypti is the main vector of Dengue and Yellow Fever flaviviruses. The organophosphate insecticide temephos is a larvicide that is used globally to control Ae. aegypti populations; many of which have in turn evolved resistance.
View Article and Find Full Text PDFIdentification of the major loci responsible for insecticide resistance in malaria vectors would aid the development and implementation of effective resistance management strategies, which are urgently needed to tackle the growing threat posed by resistance to the limited insecticides available for malaria control. Genome-wide association studies in the major malaria vector, Anopheles gambiae, have been hindered by the high degree of within-population structuring and very low levels of linkage disequilibrium hence we revisited the use of quantitative trait loci (QTL) mapping to study resistance phenotypes in this vector species. Earlier work, identified two major QTL associated with pyrethroid resistance in A.
View Article and Find Full Text PDFMosquitoes are vectors of several major human diseases and their control is mainly based on the use of chemical insecticides. Resistance of mosquitoes to organochlorines, organophosphates, carbamates and pyrethroids led to a regain of interest for the use of neonicotinoid insecticides in vector control. The present study investigated the molecular basis of neonicotinoid resistance in the mosquito Aedes aegypti.
View Article and Find Full Text PDFBackground: The mosquito Aedes aegypti is one of the most important disease vectors because it transmits two major arboviruses, dengue and yellow fever, which cause significant global morbidity and mortality. Chemical insecticides form the cornerstone of vector control. The organophosphate temephos a larvicide recommended by WHO for controlling Ae.
View Article and Find Full Text PDFChanges in gene expression before, during and after five generations of permethrin laboratory selection were monitored in six strains of Aedes aegypti: five F(2)-F(3) collections from the Yucatán Peninsula of Mexico and one F(2) from Iquitos, Peru. Three biological replicate lines were generated for each strain. The response to selection was measured as changes in the lethal and knockdown permethrin concentrations (LC(50), KC(50)) and in the frequency of the Ile1,016 substitution in the voltage-gated sodium channel (para) gene.
View Article and Find Full Text PDFBackground: Pyrethroid resistance can be considered the main threat to the continued control of many mosquito vectors of disease. Piperonyl butoxide (PBO) has been used as a synergist to help increase the efficacy of certain insecticides. This enhancement stems from its ability to inhibit two major metabolic enzyme systems, P450s and non-specific esterases, and to enhance cuticular penetration of the insecticide.
View Article and Find Full Text PDFBackground: The yellow fever mosquito Aedes aegypti is a major vector of dengue and hemorrhagic fevers, causing up to 100 million dengue infections every year. As there is still no medicine and efficient vaccine available, vector control largely based on insecticide treatments remains the only method to reduce dengue virus transmission. Unfortunately, vector control programs are facing operational challenges with mosquitoes becoming resistant to commonly used insecticides.
View Article and Find Full Text PDFThe effect of exposure of Aedes aegypti larvae for 72h to sub-lethal concentrations of the herbicide glyphosate and the polycyclic aromatic hydrocarbon benzo[a]pyrene on their subsequent tolerance to the chemical insecticides imidacloprid, permethrin and propoxur, detoxification enzyme activities and transcription of detoxification genes was investigated. Bioassays revealed a significant increase in larval tolerance to imidacloprid and permethrin following exposure to benzo[a]pyrene and glyphosate. Larval tolerance to propoxur increased moderately after exposure to benzo[a]pyrene while a minor increased tolerance was observed after exposure to glyphosate.
View Article and Find Full Text PDFBackground: Insecticide resistance in Anopheles mosquitoes is threatening the success of malaria control programmes. This is particularly true in Benin where pyrethroid resistance has been linked to the failure of insecticide treated bed nets. The role of mutations in the insecticide target sites in conferring resistance has been clearly established.
View Article and Find Full Text PDFTrans R Soc Trop Med Hyg
November 2009
Pyrethroid insecticide resistance in Anopheles gambiae sensu stricto is a major concern to malaria vector control programmes. Resistance is mainly due to target-site insensitivity arising from a single point mutation, often referred to as knockdown resistance (kdr). Metabolic-based resistance mechanisms have also been implicated in pyrethroid resistance in East Africa and are currently being investigated in West Africa.
View Article and Find Full Text PDFThe mosquito Aedes aegypti is the principal vector of dengue and yellow fever flaviviruses. Permethrin is an insecticide used to suppress Ae. aegypti adult populations but metabolic and target site resistance to pyrethroids has evolved in many locations worldwide.
View Article and Find Full Text PDFThe effect of exposure of Aedes aegypti larvae to sub-lethal doses of the pyrethroid insecticide permethrin, the organophosphate temephos, the herbicide atrazine, the polycyclic aromatic hydrocarbon fluoranthene and the heavy metal copper on their subsequent tolerance to insecticides, detoxification enzyme activities and expression of detoxification genes was investigated. Bioassays revealed a moderate increase in larval tolerance to permethrin following exposure to fluoranthene and copper while larval tolerance to temephos increased moderately after exposure to atrazine, copper and permethrin. Cytochrome P450 monooxygenases activities were induced in larvae exposed to permethrin, fluoranthene and copper while glutathione S-transferase activities were induced after exposure to fluoranthene and repressed after exposure to copper.
View Article and Find Full Text PDFInsect Biochem Mol Biol
January 2008
Annotation of the recently determined genome sequence of the major dengue vector, Aedes aegypti, reveals an abundance of detoxification genes. Here, we report the presence of 235 members of the cytochrome P450, glutathione transferase and carboxy/cholinesterase families in Ae. aegypti.
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