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In Brazil, Aedes aegypti resistance to temephos, used since 1967, was detected in several municipalities in 2000. Organophosphates were substituted by pyrethroids against adults and, in some localities, by Bti against larvae. However, high temephos resistance ratios were still detected between 2001 and 2004. Field-simulated assays confirmed a low temephos residual effect. Acethylcholinesterase and Mixed Function Oxidase profiles were not altered. In contrast, higher Esterase activity, studied with three substrates, was found in all examined populations collected in 2001. From 2001 to 2004, a slight reduction in
-Esterase (EST) and ß-EST activity together with a gradual increase of p-nitrophenyl acetate (PNPA)-EST was noted. Gluthathione-S-transferase alteration was encountered only in the northeast region in 2001, spreading the entire country thereafter. In general, except for
-EST and ß-EST, only one enzyme class was altered in each mosquito specimen. Data are discussed in the context of historic application of insecticides in Brazil.
Received September 27, 2006. Accepted for publication March 18, 2007.
Acknowledgments: The authors thank the Secretaria de Vigilância em Saúde and the Programa Nacional de Controle da Dengue for technical assistance and the Secretarias Estaduais and Municipais de Saúde from the different localities evaluated, for mosquito egg collection. We also thank Dr. W. G. Brogdon, for evaluation and validation of our biochemical protocol, Tânia Maria Rodrigues dos Santos and Nathalia Giglio Fontoura for technical assistance with, respectively, laboratory and field simulated bioassays, and Heloisa Diniz for preparing the map. The manuscript was reviewed and revised by Mitchell Raymond Lishon, native of Chicago, IL.
Financial support: This work was supported by Secretaria de Vigilância em Saúde/Ministério da Saúde, Programa de Desenvolvimento e Inovação Tecnológica em Saúde Pública/Fundação Oswaldo Cruz, Vice-Presidência de Serviços de Referência e Ambiente/Fundação Oswaldo Cruz, Conselho Nacional de Desenvolvimento Científico e Tecnológico, and Financiadora de Estudos e Projetos do Rio de Janeiro.
* Address correspondence to Denise Valle, Laboratório de Fisiologia e Controle de Artrópodes Vetores, Instituto Oswaldo Cruz, Fiocruz, Av. Brasil 4365, 21040-900 Rio de Janeiro, RJ, Brazil. E-mail: dvalle{at}ioc.fiocruz.br
Authors addresses: Isabela Reis Montella, Ademir Jesus Martins, Priscila Fernandes Viana-Medeiros, José Bento Pereira Lima, and Denise Valle, Laboratório de Fisiologia e Controle de Artrópodes Vetores, Instituto Oswaldo Cruz, Fiocruz, Av. Brasil 4365, 21040-900 Rio de Janeiro, RJ, Brazil/Instituto de Biologia do Exército, Rua Francisco Manuel 102, 20911-270 Rio de Janeiro, RJ, Brazil, Telephone: 55-21-2580-6598, E-mail: dvalle{at}ioc.fiocruz.br. Ima Aparecida Braga, Secretaria de Vigilância em Saúde, Ministério da Saúde, Esplanada dos Ministérios, Bloco G, Ed. Sede do Ministério da Saúde, 1° andar, 70058-900 Brasília, DF, Brazil.
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