5 results on '"Edi, Constant"'
Search Results
2. Intense malarial transmission during the dry season in irrigated rice-growing areas: a case study in Sakassou, Côte d'Ivoire.
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Beke, Obo Armel-Hermann, Zoh, Dounin Danielle, Assi, Serge-Brice, Gbalegba, Constant N. G., Assouho, Konan Fabrice, Azongnibo, Mardoché R. K., Edi, Constant A. V., Tanoh, Antoine M., Yapi, Grégoire Y., and Adja, Maurice A.
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ANOPHELES gambiae ,MATING grounds ,ANOPHELES ,AEDES aegypti ,VECTOR control ,MOSQUITOES - Abstract
The health district of Sakassou is one of the 83 health districts in Côte d'Ivoire, located in a zone with very high malarial transmission rates, with an incidence rate of -40% Therefore, to guide vector control methods more effectively, it was crucial to have a good understanding of the vectors in the area. This study aimed to determine the level of malarial transmission during the dry season in Sakassou, Côte d'Ivoire. Female Anopheles mosquitoes were sampled using human landing catches (HLCs) and pyrethrum spraying catches (PSCs). The larvae were collected using the 'dipping' method. A total of 10,875 adult female mosquitoes of Anopheles gambiae were collected. The PCR analysis revealed that all individuals were Anopheles coluzzii. The geographical distribution of potential breeding sites of Anopheles showed the presence of An. coluzzii in all the wetlands of the city of Sakassou. During the dry season, the human-biting rate of An. coluzzii was 139.1 bites/person/night. An exophagic trend was displayed by an adult female of An. coluzzii. The entomological inoculation rate during the dry season was 1.49 infectious bites/person/night. This study demonstrated that An. coluzzii was the main vector of malarial transmission in Sakassou, and the intensity of transmission remains high throughout the dry season. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
3. Small-scale field evaluation of PermaNet® Dual (a long-lasting net coated with a mixture of chlorfenapyr and deltamethrin) against pyrethroid-resistant Anopheles gambiae mosquitoes from Tiassalé, Côte d'Ivoire.
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Zahouli, Julien Z. B., Edi, Constant A. V., Yao, Laurence A., Lisro, Emmanuelle G., Adou, Marc, Koné, Inza, Small, Graham, Sternberg, Eleanore D., and Koudou, Benjamin G.
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ANOPHELES gambiae , *DELTAMETHRIN , *INSECTICIDE-treated mosquito nets , *MOSQUITOES , *INSECTICIDE resistance - Abstract
Background: Due to the rapid expansion of pyrethroid-resistance in malaria vectors in Africa, Global Plan for Insecticide Resistance Management (GPIRM) has recommended the development of long-lasting insecticidal nets (LLINs), containing insecticide mixtures of active ingredients with different modes of action to mitigate resistance and improve LLIN efficacy. This good laboratory practice (GLP) study evaluated the efficacy of the chlorfenapyr and deltamethrin-coated PermaNet® Dual, in comparison with the deltamethrin and synergist piperonyl butoxide (PBO)-treated PermaNet® 3.0 and the deltamethrin-coated PermaNet® 2.0, against wild free-flying pyrethroid-resistant Anopheles gambiae sensu lato (s.l.), in experimental huts in Tiassalé, Côte d'Ivoire (West Africa). Methods: PermaNet® Dual, PermaNet® 3.0 and PermaNet® 2.0, unwashed and washed (20 washes), were tested against free-flying pyrethroid-resistant An. gambiae s.l. in the experimental huts in Tiassalé, Côte d'Ivoire from March to August 2020. Complementary laboratory cone bioassays (daytime and 3-min exposure) and tunnel tests (nightly and 15-h exposure) were performed against pyrethroid-susceptible An. gambiae sensu stricto (s.s.) (Kisumu strain) and pyrethroid-resistant An. gambiae s.l. (Tiassalé strain). Results: PermaNet® Dual demonstrated significantly improved efficacy, compared to PermaNet® 3.0 and PermaNet® 2.0, against the pyrethroid-resistant An. gambiae s.l. Indeed, the experimental hut trial data showed that the mortality and blood-feeding inhibition in the wild pyrethroid-resistant An. gambiae s.l. were overall significantly higher with PermaNet® Dual compared with PermaNet® 3.0 and PermaNet® 2.0, for both unwashed and washed samples. The mortality with unwashed and washed samples were 93.6 ± 0.2% and 83.2 ± 0.9% for PermaNet® Dual, 37.5 ± 2.9% and 14.4 ± 3.9% for PermaNet® 3.0, and 7.4 ± 5.1% and 11.7 ± 3.4% for PermaNet® 2.0, respectively. Moreover, unwashed and washed samples produced the respective percentage blood-feeding inhibition of 41.4 ± 6.9% and 43.7 ± 4.8% with PermaNet® Dual, 51.0 ± 5.7% and 9.8 ± 3.6% with PermaNet® 3.0, and 12.8 ± 4.3% and − 13.0 ± 3.6% with PermaNet® 2.0. Overall, PermaNet® Dual also induced higher or similar deterrence, exophily and personal protection when compared with the standard PermaNet® 3.0 and PermaNet® 2.0 reference nets, with both unwashed and washed net samples. In contrast to cone bioassays, tunnel tests predicted the efficacy of PermaNet® Dual seen in the current experimental hut trial. Conclusion: The deltamethrin-chlorfenapyr-coated PermaNet® Dual induced a high efficacy and performed better than the deltamethrin-PBO PermaNet® 3.0 and the deltamethrin-only PermaNet® 2.0, testing both unwashed and 20 times washed samples against the pyrethroid-susceptible and resistant strains of An. gambiae s.l. The inclusion of chlorfenapyr with deltamethrin in PermaNet® Dual net greatly improved protection and control of pyrethroid-resistant An. gambiae populations. PermaNet® Dual thus represents a promising tool, with a high potential to reduce malaria transmission and provide community protection in areas compromised by mosquito vector resistance to pyrethroids. [ABSTRACT FROM AUTHOR]
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- 2023
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4. Resistance to pirimiphos-methyl in West African Anopheles is spreading via duplication and introgression of the Ace1 locus
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Grau-Bové, Xavier, Lucas, Eric, Pipini, Dimitra, Rippon, Emily, van ‘t Hof, Arjèn E., Constant, Edi, Dadzie, Samuel, Egyir-Yawson, Alexander, Essandoh, John, Chabi, Joseph, Djogbénou, Luc, Harding, Nicholas J., Miles, Alistair, Kwiatkowski, Dominic, Donnelly, Martin J., Weetman, David, Jorge Edouardo Amaya-Romero, Diego, Ayala, Battey, C. J., Philip, Bejon, Besansky, Nora J., Austin, Burt, Jorge, Cano, Caputo, Beniamino, Edi, Constant, Carlo, Costantini, Boubacar, Coulibaly, DELLA TORRE, Alessandra, Abdoulaye, Diabate´, João, Dinis, Eleanor, Drury, Jorge, Edouardo, Nohal, Elissa, John, Essandoh, Fontaine, Michael C., Godfray, H. Charles J., Hahn, Matthew W., Christa, Henrichs, Christina, Hubbart, Isaacs, Alison T., Musa, Jawara, Jeffreys, Anna E., Dushyanth, Jyothi, Maryam, Kamali, Kern, Andrew D., Kwiatkowski, Dominic P., Clarkson, Chris S., Lawniczak, Mara K. N., Gilbert Le Goff, Lucas, Eric R., Cinzia, Malangone, Mawejje, Henry D., Charles, Mbogo, Daniel, Mead, Janet, Midega, Alistair, Miles, Nwakanma, Davis C., Samantha, O’Loughlin, João, Pinto, Riehle, Michelle M., Vincent, Robert, Rockett, Kirk A., Rohatgi, Kyanne R., Kate, Rowlands, Schrider, Daniel R., Igor, Sharakhov, Victoria, Simpson, Jim, Stalker, Troco, Arlete D., Vernick, Kenneth D., David, Weetman, White, Bradley J., Wilding, Craig S., IRTA, Institute of Molecular Biology and Biotechnology (IMBB-FORTH), Foundation for Research and Technology - Hellas (FORTH), Maladies infectieuses et vecteurs : écologie, génétique, évolution et contrôle (MIVEGEC), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), Centre de Recherche Entomologique de Cotonou (CREC), Ministère de la Santé, The Wellcome Trust Centre for Human Genetics [Oxford], University of Oxford [Oxford], Liverpool School of Tropical Medicine (LSTM), Instituto de Higiene e Medicina Tropical (IHMT), Global Health and Tropical Medicine (GHTM), Vector borne diseases and pathogens (VBD), Institut de Recerca i Tecnologia Agroalimentàries = Institute of Agrifood Research and Technology (IRTA), University of Oxford, and Fontaine lab
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Cancer Research ,Insecticides ,Heredity ,Introgression ,Anopheles gambiae ,Anopheles Gambiae ,QH426-470 ,Disease Vectors ,Mosquitoes ,Ghana ,Insecticide Resistance ,Geographical Locations ,пиримифос-метил ,0302 clinical medicine ,Medical Conditions ,[SDV.MHEP.MI]Life Sciences [q-bio]/Human health and pathology/Infectious diseases ,Invertebrate Genomics ,Medicine and Health Sciences ,Genetics(clinical) ,Copy-number variation ,Association mapping ,Genetics (clinical) ,SDG 15 - Life on Land ,Data Management ,Genetics ,0303 health sciences ,education.field_of_study ,biology ,malaria vectors ,genomics ,insecticide resistance ,anopheles gambiae ,anopheles coluzzii ,Anopheles ,Eukaryota ,Phylogenetic Analysis ,Agriculture ,Genomics ,3. Good health ,Insects ,Phylogenetics ,Africa, Western ,Genetic Mapping ,Infectious Diseases ,[SDE]Environmental Sciences ,Acetylcholinesterase ,Agrochemicals ,Research Article ,Computer and Information Sciences ,африканские комары ,Evolutionary Processes ,DNA Copy Number Variations ,Arthropoda ,030231 tropical medicine ,Population ,Locus (genetics) ,Mosquito Vectors ,Genetic Introgression ,03 medical and health sciences ,SDG 3 - Good Health and Well-being ,Genes, Duplicate ,Animals ,Humans ,Evolutionary Systematics ,education ,Molecular Biology ,Ecology, Evolution, Behavior and Systematics ,030304 developmental biology ,Taxonomy ,Evolutionary Biology ,Haplotype ,Organisms ,Biology and Life Sciences ,Organothiophosphorus Compounds ,biology.organism_classification ,Invertebrates ,Malaria ,Insect Vectors ,Species Interactions ,Haplotypes ,Animal Genomics ,Vector (epidemiology) ,People and Places ,Africa ,[SDE.BE]Environmental Sciences/Biodiversity and Ecology ,Zoology ,Entomology - Abstract
Vector population control using insecticides is a key element of current strategies to prevent malaria transmission in Africa. The introduction of effective insecticides, such as the organophosphate pirimiphos-methyl, is essential to overcome the recurrent emergence of resistance driven by the highly diverse Anopheles genomes. Here, we use a population genomic approach to investigate the basis of pirimiphos-methyl resistance in the major malaria vectors Anopheles gambiae and A. coluzzii. A combination of copy number variation and a single non-synonymous substitution in the acetylcholinesterase gene, Ace1, provides the key resistance diagnostic in an A. coluzzii population from Côte d’Ivoire that we used for sequence-based association mapping, with replication in other West African populations. The Ace1 substitution and duplications occur on a unique resistance haplotype that evolved in A. gambiae and introgressed into A. coluzzii, and is now common in West Africa primarily due to selection imposed by other organophosphate or carbamate insecticides. Our findings highlight the predictive value of this complex resistance haplotype for phenotypic resistance and clarify its evolutionary history, providing tools to for molecular surveillance of the current and future effectiveness of pirimiphos-methyl based interventions., Author summary Control of mosquito populations via insecticidal tools or interventions is a mainstay of campaigns to reduce malaria transmission. However, especially in sub-Saharan Africa, continued insecticidal selection pressure on the most important species of Anopheles malaria mosquitoes has favoured the evolutionary selection of increasingly effective resistance mechanisms. We investigate the genetic basis of resistance to the organophosphate pirimiphos-methyl, the dominant insecticide now used for indoor residual spraying campaigns in Africa. Genome-wide association analysis of a population from Cote d’Ivoire showed that resistant specimens share a unique combination of mutations in one gene, the acetylcholinesterase enzyme, which constitute the prime cause of pirimiphos-methyl resistance. Further testing of these mutations in diagnostic assays involving two major malaria vectors, A. coluzzii and A. gambiae, validate their use as informative predictors of pirimiphos-methyl resistance. Using data from a large collection of whole genome sequenced specimens from a broader range of locations (Burkina-Faso, Côte d’Ivoire, Ghana, and Guinea), our evolutionary analyses demonstrate that these mutations emerged in A. gambiae and transferred into A. coluzzii by inter-specific hybridisation. Our results show how resistance mechanisms in key malaria vectors have developed and spread, and provide validated tools for molecular surveillance to inform public health campaigns.
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- 2021
5. Association of Reduced Long-Lasting Insecticidal Net Efficacy and Pyrethroid Insecticide Resistance With Overexpression of CYP6P4, CYP6P3, and CYP6Z1 in Populations of Anopheles coluzzii From Southeast Côte d'Ivoire.
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Meiwald, Anne, Clark, Emma, Kristan, Mojca, Edi, Constant, Jeffries, Claire L, Pelloquin, Bethanie, Irish, Seth R, Walker, Thomas, and Messenger, Louisa A
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MALARIA prevention ,PEST control ,INSECTICIDES ,ANIMAL experimentation ,HETEROCYCLIC compounds ,PROTECTIVE clothing ,DRUG resistance ,INSECTS ,MOSQUITOES - Abstract
Background: Resistance to major public health insecticides in Côte d'Ivoire has intensified and now threatens the long-term effectiveness of malaria vector control interventions.Methods: This study evaluated the bioefficacy of conventional and next-generation long-lasting insecticidal nets (LLINs), determined resistance profiles, and characterized molecular and metabolic mechanisms in wild Anopheles coluzzii from Southeast Côte d'Ivoire in 2019.Results: Phenotypic resistance was intense: >25% of mosquitoes survived exposure to 10 times the doses of pyrethroids required to kill susceptible populations. Similarly, the 24-hour mortality rate with deltamethrin-only LLINs was very low and not significantly different from that with an untreated net. Sublethal pyrethroid exposure did not induce significant delayed vector mortality effects 72 hours later. In contrast, LLINs containing the synergist piperonyl butoxide, or new insecticides clothianidin and chlorfenapyr, were highly toxic to A. coluzzii. Pyrethroid-susceptible A. coluzzii were significantly more likely to be infected with malaria, compared with those that survived insecticidal exposure. Pyrethroid resistance was associated with significant overexpression of CYP6P4, CYP6P3, and CYP6Z1.Conclusions: Study findings raise concerns regarding the operational failure of standard LLINs and support the urgent deployment of vector control interventions incorporating piperonyl butoxide, chlorfenapyr, or clothianidin in areas of high resistance intensity in Côte d'Ivoire. [ABSTRACT FROM AUTHOR]- Published
- 2022
- Full Text
- View/download PDF
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