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Efficacy of bifenthrin-impregnated bednets against Anopheles funestus and pyrethroid-resistant Anopheles gambiae in North Cameroon
BACKGROUND: Recent field studies indicated that insecticide-treated bednets (ITNs) maintain their efficacy despite a high frequency of the knock-down resistance (kdr) gene in Anopheles gambiae populations. It was essential to evaluate ITNs efficacy in areas with metabolic-based resistance. METHODS:...
Autores principales: | , , , , , |
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Formato: | Texto |
Lenguaje: | English |
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BioMed Central
2006
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1584243/ https://www.ncbi.nlm.nih.gov/pubmed/16961938 http://dx.doi.org/10.1186/1475-2875-5-77 |
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author | Chouaibou, Mouhamadou Simard, Frédéric Chandre, Fabrice Etang, Josiane Darriet, Frédéric Hougard, Jean-Marc |
author_facet | Chouaibou, Mouhamadou Simard, Frédéric Chandre, Fabrice Etang, Josiane Darriet, Frédéric Hougard, Jean-Marc |
author_sort | Chouaibou, Mouhamadou |
collection | PubMed |
description | BACKGROUND: Recent field studies indicated that insecticide-treated bednets (ITNs) maintain their efficacy despite a high frequency of the knock-down resistance (kdr) gene in Anopheles gambiae populations. It was essential to evaluate ITNs efficacy in areas with metabolic-based resistance. METHODS: Bifenthrin was used in this experiment because it is considered a promising candidate for bednets impregnation. Nets were treated at 50 mg/m(2), a dose that has high insecticidal activity on kdr mosquitoes and at 5 mg/m(2), a dose that kills 95% of susceptible mosquitoes under laboratory conditions with 3 minutes exposure. Bednets were holed to mimic physical damage. The trial was conducted in three experimental huts from Pitoa, North-Cameroon where Anopheles gambiae displays metabolic resistance and cohabits with An. funestus. RESULTS: Bifenthrin at 50 mg/m(2 )significantly reduced anophelines' entry rate (>80%). This was not observed at 5 mg/m(2). Both treatments increased exophily in An. gambiae, and to a lesser extent in An. funestus. With bifenthrin at high dosage, over 60% reduction in blood feeding and 75–90% mortality rates were observed in both vectors. Despite presence of holes, only a single An. gambiae and two An. funestus females were collected inside the treated net, and all were found dead. The same trends were observed with low dosage bifenthrin though in most cases, no significant difference was found with the untreated control net. CONCLUSION: Bifenthrin-impregnated bednets at 50 mg/m(2 )were efficient in the reduction of human-vector contact in Pitoa. Considerable personal protection was gained against An. funestus and metabolic pyrethroid resistant An. gambiae populations. |
format | Text |
id | pubmed-1584243 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2006 |
publisher | BioMed Central |
record_format | MEDLINE/PubMed |
spelling | pubmed-15842432006-09-29 Efficacy of bifenthrin-impregnated bednets against Anopheles funestus and pyrethroid-resistant Anopheles gambiae in North Cameroon Chouaibou, Mouhamadou Simard, Frédéric Chandre, Fabrice Etang, Josiane Darriet, Frédéric Hougard, Jean-Marc Malar J Research BACKGROUND: Recent field studies indicated that insecticide-treated bednets (ITNs) maintain their efficacy despite a high frequency of the knock-down resistance (kdr) gene in Anopheles gambiae populations. It was essential to evaluate ITNs efficacy in areas with metabolic-based resistance. METHODS: Bifenthrin was used in this experiment because it is considered a promising candidate for bednets impregnation. Nets were treated at 50 mg/m(2), a dose that has high insecticidal activity on kdr mosquitoes and at 5 mg/m(2), a dose that kills 95% of susceptible mosquitoes under laboratory conditions with 3 minutes exposure. Bednets were holed to mimic physical damage. The trial was conducted in three experimental huts from Pitoa, North-Cameroon where Anopheles gambiae displays metabolic resistance and cohabits with An. funestus. RESULTS: Bifenthrin at 50 mg/m(2 )significantly reduced anophelines' entry rate (>80%). This was not observed at 5 mg/m(2). Both treatments increased exophily in An. gambiae, and to a lesser extent in An. funestus. With bifenthrin at high dosage, over 60% reduction in blood feeding and 75–90% mortality rates were observed in both vectors. Despite presence of holes, only a single An. gambiae and two An. funestus females were collected inside the treated net, and all were found dead. The same trends were observed with low dosage bifenthrin though in most cases, no significant difference was found with the untreated control net. CONCLUSION: Bifenthrin-impregnated bednets at 50 mg/m(2 )were efficient in the reduction of human-vector contact in Pitoa. Considerable personal protection was gained against An. funestus and metabolic pyrethroid resistant An. gambiae populations. BioMed Central 2006-09-11 /pmc/articles/PMC1584243/ /pubmed/16961938 http://dx.doi.org/10.1186/1475-2875-5-77 Text en Copyright © 2006 Chouaibou et al; licensee BioMed Central Ltd. http://creativecommons.org/licenses/by/2.0 This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( (http://creativecommons.org/licenses/by/2.0) ), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. |
spellingShingle | Research Chouaibou, Mouhamadou Simard, Frédéric Chandre, Fabrice Etang, Josiane Darriet, Frédéric Hougard, Jean-Marc Efficacy of bifenthrin-impregnated bednets against Anopheles funestus and pyrethroid-resistant Anopheles gambiae in North Cameroon |
title | Efficacy of bifenthrin-impregnated bednets against Anopheles funestus and pyrethroid-resistant Anopheles gambiae in North Cameroon |
title_full | Efficacy of bifenthrin-impregnated bednets against Anopheles funestus and pyrethroid-resistant Anopheles gambiae in North Cameroon |
title_fullStr | Efficacy of bifenthrin-impregnated bednets against Anopheles funestus and pyrethroid-resistant Anopheles gambiae in North Cameroon |
title_full_unstemmed | Efficacy of bifenthrin-impregnated bednets against Anopheles funestus and pyrethroid-resistant Anopheles gambiae in North Cameroon |
title_short | Efficacy of bifenthrin-impregnated bednets against Anopheles funestus and pyrethroid-resistant Anopheles gambiae in North Cameroon |
title_sort | efficacy of bifenthrin-impregnated bednets against anopheles funestus and pyrethroid-resistant anopheles gambiae in north cameroon |
topic | Research |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1584243/ https://www.ncbi.nlm.nih.gov/pubmed/16961938 http://dx.doi.org/10.1186/1475-2875-5-77 |
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