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Evidence of increasing Leu-Phe knockdown resistance mutation in Anopheles gambiae from Niger following a nationwide long-lasting insecticide-treated nets implementation

BACKGROUND: At the end of 2005, a nationwide long-lasting insecticide-treated net (LLIN) distribution targeting the most vulnerable populations was implemented throughout Niger. A large number of studies in Africa have reported the existence of anopheline populations resistant to various insecticide...

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Autores principales: Czeher, Cyrille, Labbo, Rabiou, Arzika, Ibrahim, Duchemin, Jean-Bernard
Formato: Texto
Lenguaje:English
Publicado: BioMed Central 2008
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2562389/
https://www.ncbi.nlm.nih.gov/pubmed/18817574
http://dx.doi.org/10.1186/1475-2875-7-189
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author Czeher, Cyrille
Labbo, Rabiou
Arzika, Ibrahim
Duchemin, Jean-Bernard
author_facet Czeher, Cyrille
Labbo, Rabiou
Arzika, Ibrahim
Duchemin, Jean-Bernard
author_sort Czeher, Cyrille
collection PubMed
description BACKGROUND: At the end of 2005, a nationwide long-lasting insecticide-treated net (LLIN) distribution targeting the most vulnerable populations was implemented throughout Niger. A large number of studies in Africa have reported the existence of anopheline populations resistant to various insecticides, partly due to knockdown resistance (kdr) mutations, but few operational wide-scale control programmes were coupled with the monitoring of such mutations. The distribution of the kdr-west (kdr-w) Leu-Phe mutation was studied in Anopheles gambiae s.l. populations from Niger and temporal variations were monitored following the nationwide LLIN implementation. METHODS: Mosquitoes were collected from 14 localities during the wet seasons of 2005, 2006 and 2007 with additional sampling in the capital city, Niamey. After morphological identification of Anopheles gambiae s.l. specimens, DNA extracts were used for the determination of species and molecular forms of the Anopheles gambiae complex and for the detection of the kdr-w mutation. RESULTS: Around 1,500 specimens collected in the three consecutive years were analysed. All Anopheles arabiensis specimens analysed were homozygous susceptible, whereas the few Anopheles gambiae S forms exhibited a high overall kdr-w frequency. The M form samples exhibited a low overall kdr-w frequency before the LLIN distribution, that increased significantly in the two wet season collections following the LLIN distribution. Higher kdr frequencies were repeatedly noticed within host-seeking females compared to resting ones in indoor collections. In addition, preliminary results in M form urban populations from Niamey showed far higher kdr frequencies than in all of the rural sites studied. DISCUSSION: This study describes the first case of kdr mutation in Anopheles gambiae populations from Niger. It is suspected that the LLIN have caused the important temporal increase of kdr-w mutation observed during this study. While the kdr mutation is still found at a low level, this rapid increase could potentially lead to high kdr frequencies within a few years. CONCLUSION: These results are of prime importance in the effort to document multiple effects of operational control programmes on mosquito vectors, and to conceive sustainable control strategies for future malaria control programmes.
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spelling pubmed-25623892008-10-07 Evidence of increasing Leu-Phe knockdown resistance mutation in Anopheles gambiae from Niger following a nationwide long-lasting insecticide-treated nets implementation Czeher, Cyrille Labbo, Rabiou Arzika, Ibrahim Duchemin, Jean-Bernard Malar J Research BACKGROUND: At the end of 2005, a nationwide long-lasting insecticide-treated net (LLIN) distribution targeting the most vulnerable populations was implemented throughout Niger. A large number of studies in Africa have reported the existence of anopheline populations resistant to various insecticides, partly due to knockdown resistance (kdr) mutations, but few operational wide-scale control programmes were coupled with the monitoring of such mutations. The distribution of the kdr-west (kdr-w) Leu-Phe mutation was studied in Anopheles gambiae s.l. populations from Niger and temporal variations were monitored following the nationwide LLIN implementation. METHODS: Mosquitoes were collected from 14 localities during the wet seasons of 2005, 2006 and 2007 with additional sampling in the capital city, Niamey. After morphological identification of Anopheles gambiae s.l. specimens, DNA extracts were used for the determination of species and molecular forms of the Anopheles gambiae complex and for the detection of the kdr-w mutation. RESULTS: Around 1,500 specimens collected in the three consecutive years were analysed. All Anopheles arabiensis specimens analysed were homozygous susceptible, whereas the few Anopheles gambiae S forms exhibited a high overall kdr-w frequency. The M form samples exhibited a low overall kdr-w frequency before the LLIN distribution, that increased significantly in the two wet season collections following the LLIN distribution. Higher kdr frequencies were repeatedly noticed within host-seeking females compared to resting ones in indoor collections. In addition, preliminary results in M form urban populations from Niamey showed far higher kdr frequencies than in all of the rural sites studied. DISCUSSION: This study describes the first case of kdr mutation in Anopheles gambiae populations from Niger. It is suspected that the LLIN have caused the important temporal increase of kdr-w mutation observed during this study. While the kdr mutation is still found at a low level, this rapid increase could potentially lead to high kdr frequencies within a few years. CONCLUSION: These results are of prime importance in the effort to document multiple effects of operational control programmes on mosquito vectors, and to conceive sustainable control strategies for future malaria control programmes. BioMed Central 2008-09-25 /pmc/articles/PMC2562389/ /pubmed/18817574 http://dx.doi.org/10.1186/1475-2875-7-189 Text en Copyright © 2008 Czeher 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
Czeher, Cyrille
Labbo, Rabiou
Arzika, Ibrahim
Duchemin, Jean-Bernard
Evidence of increasing Leu-Phe knockdown resistance mutation in Anopheles gambiae from Niger following a nationwide long-lasting insecticide-treated nets implementation
title Evidence of increasing Leu-Phe knockdown resistance mutation in Anopheles gambiae from Niger following a nationwide long-lasting insecticide-treated nets implementation
title_full Evidence of increasing Leu-Phe knockdown resistance mutation in Anopheles gambiae from Niger following a nationwide long-lasting insecticide-treated nets implementation
title_fullStr Evidence of increasing Leu-Phe knockdown resistance mutation in Anopheles gambiae from Niger following a nationwide long-lasting insecticide-treated nets implementation
title_full_unstemmed Evidence of increasing Leu-Phe knockdown resistance mutation in Anopheles gambiae from Niger following a nationwide long-lasting insecticide-treated nets implementation
title_short Evidence of increasing Leu-Phe knockdown resistance mutation in Anopheles gambiae from Niger following a nationwide long-lasting insecticide-treated nets implementation
title_sort evidence of increasing leu-phe knockdown resistance mutation in anopheles gambiae from niger following a nationwide long-lasting insecticide-treated nets implementation
topic Research
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2562389/
https://www.ncbi.nlm.nih.gov/pubmed/18817574
http://dx.doi.org/10.1186/1475-2875-7-189
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