Pyrethroid susceptibility reversal in < i > Aedes aegypti < /i > : A longitudinal study in Tapachula, Mexico

by Patricia Penilla-Navarro, Francisco Solis-Santoyo, Alma Lopez-Solis, Americo D. Rodriguez, Farah Vera-Maloof, Saul Lozano, Elsa Contreras-Mej ía, Geovanni Vázquez-Samayoa, Rene Torreblanca-Lopez, Rushika Perera, William C. Black IV, Karla Saavedra-Rodriguez Pyrethroid resistance inAedes aegypti has become widespread after almost two decades of frequent applications to reduce the transmission of mosquito-borne diseases. Because few insecticide classes are available for public health use, insecticide resistance management (IRM) is proposed as a strategy to retain their use. A key hypothesis of IRM assumes that negative fitness is associated with resistance, and when insecticides are removed from use, susceptibility is restored. In Tapachula, Mexico, pyrethroids (PYRs) were used exclusively by dengue control programs for 15 years, thereby contributing to selection for high PYR resistance in mosquitoes and failure in dengue control. In 2013, PYRs were replaced by organophosphates —insecticides from a class with a different mode of action. To test the hypothesis that PYR resistance is reversed in the absence of PYRs, we monitoredAe.aegypti ’s PYR resistance from 2016 to 2021 in Tapachula. We observed significant declining rates in the lethal concentration 50 (LC50), for permethrin and deltamethrin. For each month following the discontinuation of PYR use by vector control programs, we observed increases in the odds of mosquitoes dying by 1.5% and 8.4% for permethrin and d...
Source: PLoS Neglected Tropical Diseases - Category: Tropical Medicine Authors: Source Type: research