Please use this identifier to cite or link to this item:
https://www.arca.fiocruz.br/handle/icict/28968
RESISTANCE TO DELTAMETHRIN BY DOMESTIC AND WILD TRIATOMA INFESTANS POPULATIONS IN THE MUNICIPALITY OF TORO TORO, POTOSI, BOLIVIA
Doença de Chagas
Deltamethrin
resistencia a inseticidas
macro e microgeografia
Triatoma infestan
Chagas disease
Deltamethrin
Insecticide resistance
Macro- and microgeography
Triatoma infestan
Author
Affilliation
Laboratório de Referência Triatomíneos e Epidemiologia da Doença de Chagas. Fundação Oswaldo Cruz. Instituto René Rachou. Belo Horizonte, MG, Brasil
Laboratório de Referência Triatomíneos e Epidemiologia da Doença de Chagas. Fundação Oswaldo Cruz. Instituto René Rachou. Belo Horizonte, MG, Brasil
Laboratório de Referência Triatomíneos e Epidemiologia da Doença de Chagas. Fundação Oswaldo Cruz. Instituto René Rachou. Belo Horizonte, MG, Brasil
CEADES Salud y Medio Ambiente/Plataforma Chagas. Cochabamba, Bolivia
Servicio Departamental de Salud – Potosi. Programa Nacional de Chagas. Potosi, Bolivia
Laboratório de Referência Triatomíneos e Epidemiologia da Doença de Chagas. Fundação Oswaldo Cruz. Instituto René Rachou. Belo Horizonte, MG, Brasil
Laboratório de Referência Triatomíneos e Epidemiologia da Doença de Chagas. Fundação Oswaldo Cruz. Instituto René Rachou. Belo Horizonte, MG, Brasil
Laboratório de Referência Triatomíneos e Epidemiologia da Doença de Chagas. Fundação Oswaldo Cruz. Instituto René Rachou. Belo Horizonte, MG, Brasil
CEADES Salud y Medio Ambiente/Plataforma Chagas. Cochabamba, Bolivia
Servicio Departamental de Salud – Potosi. Programa Nacional de Chagas. Potosi, Bolivia
Laboratório de Referência Triatomíneos e Epidemiologia da Doença de Chagas. Fundação Oswaldo Cruz. Instituto René Rachou. Belo Horizonte, MG, Brasil
Abstract
BACKGROUND: Chemical control with pyrethroid insecticides has been effective in reducing endemic areas of distribution of Triatoma infestans in the Southern Cone, as well as Bolivia; this had considerably reduced the infestation of households in a large part of the territory. Nowadays, areas such as the Chaco and the Inter-Andean Valleys are regions where the reach of vector control strategies is becoming limited, and infestations of insecticide-treated households are reported more often. The objective of this study was to determine if the persistence of T. infestans stems from changes in the susceptibility of its toxicological profile in four communities in the municipality of Toro Toro, Potosi, Bolivia.
METHODS: Susceptibility to deltamethrin of wild and domestic populations of T. infestans was evaluated in two stages (16 populations before and 13 populations after spraying) among DUs (structures in the intra- and peridomicile) and wild ecotopes, in four communities. Serial dilutions of deltamethrin in acetone (0.2 μl) were applied topically on standardized first-stage nymphs. Dose-response results were analyzed with the software PoloPlus and the relationships between lethal doses (LD) and resistance ratios (RR50) were determined.
RESULTS: Different degrees of RR50 were detected among the populations before and after spraying (25.66-54.70 and 21.91-40.67, respectively), as well as in different ecotopes within a DU (DU JC 3, 28.06-36.13, in mixed structures of corrals and chicken coops; and DU JG 3, 46.27-25.70, in kitchen roofs), or in the wild environment of the community JG Sil (29.21-40.67). The mortality of insects undergoing diagnostic dose (DD) was never higher than 34%.
CONCLUSION: The results obtained in this study showed resistance of T. infestans to deltamethrin in four communities, hence the complexity of this phenomenon is not only limited to the level of communities, but also applies to the microgeographical level, as in different ecotopes present within the DUs. This phenomenon should be considered while planning the activities of control programs.
Keywords in Portuguese
BoliviaDoença de Chagas
Deltamethrin
resistencia a inseticidas
macro e microgeografia
Triatoma infestan
Keywords
BoliviaChagas disease
Deltamethrin
Insecticide resistance
Macro- and microgeography
Triatoma infestan
Share