Autor(es): Karunaratne, SHPP; Hemingway, J

Resumo: To determine the levels of malathion resistance and prevalence of the malathion carboxylesterase mechanism among mosquitoes in Sri Lanka.Methods Bioassays were carried out using WHO-recommended methods on samples of the following Sri Lankan mosquito vectors: Culex quinquefasciatus, C tritaeniorhynchus, C. gelidus; Anopheles culicifacies B, A subpictus; Aedes aegypti and A. albopictus.Findings M a lath ion-specific carboxylesterase mechanisms were found in A. culicifacies and A. subpictus, both giving high rates of insecticide metabolism. In contrast, malathion resistance in C quinquefasciatus and C. tritaeniorhynchus is linked to broad-spectrum resistance to organophosphorus compounds due to elevated levels of esterases that sequester malaoxon, but are unable to metabolize malathion.Conclusions Resistance among the Anopheles spp. must have occurred as a direct result of antimalarial activities, since malathion use in Sri Lanka is limited to public health treatments. In contrast, resistance among Culex spp. has resulted from large-scale use of the organophosphorus insecticide group as larvicides for filariasis control and on rice paddy, where C, tritaeniorhynchus predominantly breeds, for agricultural purposes.

Palavras-Chave: Malathion/Metabolism; Carboxylic Ester Hydrolases/Metabolism; Insecticide Resistance; Culicidae/Metabolism; Culex/Metabolism; Anopheles/Metabolism; Aedes/Metabolism; Prevalence; Sri Lanka

Imprenta: Bulletin of The World Health Organization, v. 79, n. 11, p. 1060-1064, 2001

Descritores: Aedes aegypti - Larvicide ; Aedes aegypti - Public health

Data de publicação: 2001