A significant increase in kdr in Anopheles gambiae is associated with an intensive vector control intervention in Burundi highlands.

Hdl Handle:
http://hdl.handle.net/10144/48803
Title:
A significant increase in kdr in Anopheles gambiae is associated with an intensive vector control intervention in Burundi highlands.
Authors:
Protopopoff, N; Verhaeghen, K; Van Bortel, W; Roelants, P; Marcotty, T; Baza, D; D'Alessandro, U; Coosemans, M
Journal:
Tropical Medicine & International Health
Abstract:
OBJECTIVES AND METHODS: In Burundi, the occurrence of the knock down resistance (kdr) mutation in Anopheles gambiae sensu lato (s.l.) was determined for six consecutive years within the framework of a vector control programme. Findings were also linked with the insecticide resistance status observed with bioassay in An. gambiae s.l. and An. funestus. RESULTS: The proportion of An. gambiae s.l. carrying the East Leu-Ser kdr mutation was 1% before the spraying intervention in 2002; by 2007 it was 86% in sprayed valleys and 67% in untreated valleys. Multivariate analysis showed that increased risk of carrying the kdr mutation is associated with spraying interventions, location and time. In bioassays conducted between 2005 and 2007 at five sites, An. funestus was susceptible to permethrin, deltamethrin and DDT. Anopheles gambiae s.l. remained susceptible or tolerant to deltamethrin and resistant to DDT and permethrin, but only when kdr allele carriers reached 90% of the population. CONCLUSIONS: The cross-resistance against DDT and permethrin in Karuzi suggests a possible kdr resistance mechanism. Nevertheless, the homozygous resistant genotype alone does not entirely explain the bioassay results, and other mechanisms conferring resistance cannot be ruled out. After exposure to all three insecticides, homozygote individuals for the kdr allele dominate among the surviving An. gambiae s.l. This confirms the potential selection pressure of pyrethroids on kdr mutation. However, the high occurrence of the kdr mutation, even at sites far from the sprayed areas, suggests a selection pressure other than that exerted by the vector control programme.
Affiliation:
Department of Parasitology, Prince Leopold Institute of Tropical Medicine, Antwerp, Belgium. nprotopopoff@itg.be
Issue Date:
Dec-2008
URI:
http://hdl.handle.net/10144/48803
DOI:
10.1111/j.1365-3156.2008.02164.x
PubMed ID:
18983277
Language:
en
ISSN:
1365-3156
Appears in Collections:
Malaria

Full metadata record

DC FieldValue Language
dc.contributor.authorProtopopoff, N-
dc.contributor.authorVerhaeghen, K-
dc.contributor.authorVan Bortel, W-
dc.contributor.authorRoelants, P-
dc.contributor.authorMarcotty, T-
dc.contributor.authorBaza, D-
dc.contributor.authorD'Alessandro, U-
dc.contributor.authorCoosemans, M-
dc.date.accessioned2009-02-10T16:03:16Z-
dc.date.available2009-02-10T16:03:16Z-
dc.date.issued2008-12-
dc.identifier.citationA significant increase in kdr in Anopheles gambiae is associated with an intensive vector control intervention in Burundi highlands. 2008, 13 (12):1479-87 Trop. Med. Int. Healthen
dc.identifier.issn1365-3156-
dc.identifier.pmid18983277-
dc.identifier.doi10.1111/j.1365-3156.2008.02164.x-
dc.identifier.urihttp://hdl.handle.net/10144/48803-
dc.description.abstractOBJECTIVES AND METHODS: In Burundi, the occurrence of the knock down resistance (kdr) mutation in Anopheles gambiae sensu lato (s.l.) was determined for six consecutive years within the framework of a vector control programme. Findings were also linked with the insecticide resistance status observed with bioassay in An. gambiae s.l. and An. funestus. RESULTS: The proportion of An. gambiae s.l. carrying the East Leu-Ser kdr mutation was 1% before the spraying intervention in 2002; by 2007 it was 86% in sprayed valleys and 67% in untreated valleys. Multivariate analysis showed that increased risk of carrying the kdr mutation is associated with spraying interventions, location and time. In bioassays conducted between 2005 and 2007 at five sites, An. funestus was susceptible to permethrin, deltamethrin and DDT. Anopheles gambiae s.l. remained susceptible or tolerant to deltamethrin and resistant to DDT and permethrin, but only when kdr allele carriers reached 90% of the population. CONCLUSIONS: The cross-resistance against DDT and permethrin in Karuzi suggests a possible kdr resistance mechanism. Nevertheless, the homozygous resistant genotype alone does not entirely explain the bioassay results, and other mechanisms conferring resistance cannot be ruled out. After exposure to all three insecticides, homozygote individuals for the kdr allele dominate among the surviving An. gambiae s.l. This confirms the potential selection pressure of pyrethroids on kdr mutation. However, the high occurrence of the kdr mutation, even at sites far from the sprayed areas, suggests a selection pressure other than that exerted by the vector control programme.en
dc.language.isoenen
dc.rightsArchived on this site with the kind permission of Wiley-Blackwell, [url]http://www.blackwell-synergy.com/loi/tmi[/url]en
dc.subject.meshAnimalsen
dc.subject.meshAnopheles gambiaeen
dc.subject.meshBurundien
dc.subject.meshDDTen
dc.subject.meshGenes, Insecten
dc.subject.meshGenotypeen
dc.subject.meshHomozygoteen
dc.subject.meshInsecticide Resistanceen
dc.subject.meshInsecticidesen
dc.subject.meshMosquito Controlen
dc.subject.meshMutationen
dc.subject.meshNitrilesen
dc.subject.meshPermethrinen
dc.subject.meshPyrethrinsen
dc.titleA significant increase in kdr in Anopheles gambiae is associated with an intensive vector control intervention in Burundi highlands.en
dc.contributor.departmentDepartment of Parasitology, Prince Leopold Institute of Tropical Medicine, Antwerp, Belgium. nprotopopoff@itg.been
dc.identifier.journalTropical Medicine & International Healthen

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