Malaria mosquitoes mate in swarms, but how these swarms are formed and maintained remains poorly understood. We characterized three-dimensional spatiotemporal flight kinematics of males swarming at sunset above a ground marker. The location, shape, and volume of swarms were highly stereotypic, consistent over the complete swarming duration.
View Article and Find Full Text PDFTopical repellents provide protection against mosquito bites and their efficacy is often assessed using the arm-in-cage test. The arm-in-cage test estimates the repellent's protection time by exposing a repellent-treated forearm to host-seeking mosquitoes inside a cage at regular intervals until the first confirmed mosquito bite. However, the test does not reveal the repellents' behavioural mode of action.
View Article and Find Full Text PDFBackground: Indoor residual spraying (IRS) is one of the most effective malaria control tools. However, its application has become limited to specific contexts due to the increased costs of IRS products and implementation programmes. Selective spraying-selective spray targeted to particular areas/surfaces of dwellings-has been proposed to maintain the malaria control and resistance-management benefits of IRS while decreasing the costs of the intervention.
View Article and Find Full Text PDFIn addition to killing, mosquito nets treated with permethrin have been claimed to repel mosquitoes, reducing their success in passing through a holed net. We have tested this hypothesis by tracking mosquitoes in a modified World Health Organization tunnel test. In the original assay, mosquitoes are released at one end of the tunnel and have to pass through a holed piece of net to reach the bait at the other end.
View Article and Find Full Text PDFIn pursuing novel therapeutic solutions, drug discovery and development rely on efficiently utilising existing knowledge and resources. Repurposing know-how, a strategy that capitalises on previously acquired information and expertise, has emerged as a powerful approach to accelerate drug discovery and development processes, often at a fraction of the costs of de novo developments. For 80 years, collaborating within a network of partnerships, the Swiss Tropical and Public Health Institute (Swiss TPH) has been working along a value chain from innovation to validation and application to combat poverty-related diseases.
View Article and Find Full Text PDFBackground: Pyrethroid resistance in the key malaria vectors threatens the success of pyrethroid-treated nets. To overcome pyrethroid resistance, Interceptor G2 (IG2), a 'first-in-class' dual insecticidal net that combines alpha-cypermethrin with chlorfenapyr, was developed. Chlorfenapyr is a pro-insecticide, requiring bio-activation by oxidative metabolism within the insect's mitochondria, constituting a mode of action preventing cross-resistance to pyrethroids.
View Article and Find Full Text PDFBackground: Ivermectin (22,23-dihydroavermectin B: HB) is an endectocide used to treat worm infections and ectoparasites including lice and scabies mites. Furthermore, survival of malaria transmitting Anopheles mosquitoes is strongly decreased after feeding on humans recently treated with ivermectin. Currently, mass drug administration of ivermectin is under investigation as a potential novel malaria vector control tool to reduce Plasmodium transmission by mosquitoes.
View Article and Find Full Text PDFBackground: Knowing the species composition and insecticide resistance status of the target vector population is important to guide malaria vector control. The aim of this study was to characterize the malaria vector population in terms of species composition, insecticide susceptibility status and potential underlying resistance mechanisms in Ellibou, southern Côte d'Ivoire.
Methods: A 1-year longitudinal entomological survey was conducted using light traps and pyrethroid spray catches to sample adult mosquitoes in combination with larval sampling.
Human and animal vector-borne diseases, particularly mosquito-borne diseases, are emerging or re-emerging worldwide. Six invasive mosquito (AIM) species were introduced to Europe since the 1970s: , , , , and . Here, we report the results of AIMSurv2020, the first pan-European surveillance effort for AIMs.
View Article and Find Full Text PDFBackground: The continued spread of insecticide resistance in mosquito vectors of malaria and arboviral diseases may lead to operational failure of insecticide-based interventions if resistance is not monitored and managed efficiently. This study aimed to develop and validate a new WHO glass bottle bioassay method as an alternative to the WHO standard insecticide tube test to monitor mosquito susceptibility to new public health insecticides with particular modes of action, physical properties or both.
Methods: A multi-centre study involving 21 laboratories worldwide generated data on the susceptibility of seven mosquito species (Aedes aegypti, Aedes albopictus, Anopheles gambiae sensu stricto [An.
Background: Colonization of large part of Europe by the Asian tiger mosquito Aedes albopictus is causing autochthonous transmission of chikungunya and dengue exotic arboviruses. While pyrethroids are recommended only to reduce/limit transmission, they are widely implemented to reduce biting nuisance and to control agricultural pests, increasing the risk of insurgence of resistance mechanisms. Worryingly, pyrethroid resistance (with mortality < 70%) was recently reported in Ae.
View Article and Find Full Text PDForiginates from Southeast Asia and is considered one of the most invasive species globally. This mosquito is a nuisance and a disease vector of significant public health relevance. In Europe, is firmly established and widespread south of the Alps, a mountain range that forms a formidable biogeographic barrier to many organisms.
View Article and Find Full Text PDFBackground: Prospective malaria public health interventions are initially tested for entomological impact using standardised experimental hut trials. In some cases, data are collated as aggregated counts of potential outcomes from mosquito feeding attempts given the presence of an insecticidal intervention. Comprehensive data i.
View Article and Find Full Text PDFInsecticide resistance in Anopheles mosquitoes is seriously threatening the success of insecticide-based malaria vector control. Surveillance of insecticide resistance in mosquito populations and identifying the underlying mechanisms enables optimisation of vector control strategies. Here, we investigated the molecular mechanisms of insecticide resistance in three Anopheles coluzzii field populations from southern Côte d'Ivoire, including Agboville, Dabou and Tiassalé.
View Article and Find Full Text PDFFifth generation networks (5G) will be associated with a partial shift to higher carrier frequencies, including wavelengths comparable in size to insects. This may lead to higher absorption of radio frequency (RF) electromagnetic fields (EMF) by insects and could cause dielectric heating. The yellow fever mosquito (Aedes aegypti), a vector for diseases such as yellow and dengue fever, favors warm climates.
View Article and Find Full Text PDFPrevious studies have indicated widespread insecticide resistance in malaria vector populations from Cameroon. However, the intensity of this resistance and underlying mechanisms are poorly known. Therefore, we conducted three cross-sectional resistance surveys between April 2018 and October 2019, using the revised World Health Organization protocol, which includes resistance incidences and intensity assessments.
View Article and Find Full Text PDFMosquitoes are vectors of major diseases such as dengue fever and malaria. Mass drug administration of endectocides to humans and livestock is a promising complementary approach to current insecticide-based vector control measures. The aim of this study was to establish an insect model for pharmacokinetic and drug-drug interaction studies to develop sustainable endectocides for vector control.
View Article and Find Full Text PDFOver the past three decades, Europe has witnessed an increased spread of invasive aedine mosquito species, most notably Aedes albopictus, a key vector of chikungunya, dengue and Zika virus. While its distribution in southern Europe is well documented, its dispersal modes across the Alps remain poorly investigated, preventing a projection of future scenarios beyond its current range in order to target mosquito control. To monitor the presence and frequency of invasive Aedes mosquitoes across and beyond the Alps we set oviposition and BG-Sentinel traps at potential points of entry with a focus on motorway service areas across Switzerland.
View Article and Find Full Text PDFPeople's knowledge, attitudes, practices and beliefs (KAPB) pertaining to malaria are generally well described. However, little is known about population knowledge and awareness of insecticide resistance in malaria vectors. The aim of this study was to investigate KAPB related to insecticide resistance in malaria vectors due to the use of insecticides in agriculture and the prevention against mosquitoes.
View Article and Find Full Text PDFBackground: Understanding the dispersal dynamics of invasive mosquito species is fundamental to improve vector surveillance and to target control efforts. Aedes albopictus has been deemed a poor flyer as its range of active dispersal is generally assumed to be limited to a few hundred metres, while laboratory studies suggest this mosquito could actually fly several kilometres. The discrepancy may be due to differences in the local environment or to the methodological approach.
View Article and Find Full Text PDFBackground: The threat of mosquito-borne diseases is increasing in continental Europe as demonstrated by several autochthonous chikungunya, dengue and West Nile virus outbreaks. In Switzerland, despite the presence of competent vectors, routine surveillance of arboviruses in mosquitoes is not being carried out, mainly due to the high costs associated with the need of a constant cold chain and laborious processing of thousands of mosquitoes. An alternative approach is using honey-baited nucleic acid preserving cards (FTA cards) to collect mosquito saliva that may be analysed for arboviruses.
View Article and Find Full Text PDFFungi produce various defense proteins against antagonists, including ribotoxins. These toxins cleave a single phosphodiester bond within the universally conserved sarcin-ricin loop of ribosomes and inhibit protein biosynthesis. Here, we report on the structure and function of ageritin, a previously reported ribotoxin from the edible mushroom The amino acid sequence of ageritin was derived from cDNA isolated from the dikaryon AAE-3 and lacks, according to prediction, a signal peptide for classical secretion, predicting a cytoplasmic localization of the protein.
View Article and Find Full Text PDFThe past 40 years have seen a dramatic emergence of epidemic arboviral diseases transmitted primarily by mosquitoes. The frequency and magnitude of the epidemics, especially those transmitted by urban Aedes species, have progressively increased over time, accelerating in the past 10 years. To reduce the burden and threat of vector-borne diseases, the World Health Organization (WHO) has recently adopted the Global Vector Control Response (GVCR) in order to support countries in implementing effective sustainable vector control.
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