Deltamethrin resistance in Aedes aegypti results in treatment failure in Merida, Mexico.

• Published in: PLOS Neglected Tropical Diseases
• Main Authors: Gonzalo M Vazquez-Prokopec, Anuar Medina-Barreiro, Azael Che-Mendoza, Felipe Dzul-Manzanilla, Fabian Correa-Morales, Guillermo Guillermo-May, Wilbert Bibiano-Marín, Valentín Uc-Puc, Eduardo Geded-Moreno, José Vadillo-Sánchez, Jorge Palacio-Vargas, Scott A Ritchie, Audrey Lenhart, Pablo Manrique-Saide
• Format: Article in Journal/Newspaper
• Language: English
• Published: Public Library of Science (PLoS) 2017
• Subjects: Arctic medicine. Tropical medicine; RC955-962; Public aspects of medicine; RA1-1270; Arctic
• Online Access: https://doi.org/10.1371/journal.pntd.0005656; https://doaj.org/article/7128cb2c2b6949e4ac0711e31cc3b9b0

The operational impact of deltamethrin resistance on the efficacy of indoor insecticide applications to control Aedes aegypti was evaluated in Merida, Mexico. A randomized controlled trial quantified the efficacy of indoor residual spraying (IRS) against adult Ae. aegypti in houses treated with either deltamethrin (to which local Ae. aegypti expressed a high degree of resistance) or bendiocarb (to which local Ae. aegypti were fully susceptible) as compared to untreated control houses. All adult Ae. aegypti infestation indices during 3 months post-spraying were significantly lower in houses treated with bendiocarb compared to untreated houses (odds ratio <0.75; incidence rate ratio < 0.65) whereas no statistically significant difference was detected between the untreated and the deltamethrin-treated houses. On average, bendiocarb spraying reduced Ae. aegypti abundance by 60% during a 3-month period. Results demonstrate that vector control efficacy can be significantly compromised when the insecticide resistance status of Ae. aegypti populations is not taken into consideration.