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Insecticide resistance in Aedes aegypti from Tapachula, Mexico: Spatial variation and response to historical insecticide use.
Solis-Santoyo, Francisco; Rodriguez, Americo D; Penilla-Navarro, R Patricia; Sanchez, Daniel; Castillo-Vera, Alfredo; Lopez-Solis, Alma D; Vazquez-Lopez, Eduardo D; Lozano, Saul; Black, William C; Saavedra-Rodriguez, Karla.
Afiliação
  • Solis-Santoyo F; Instituto Nacional de Salud Pública, Centro Regional de Investigación en Salud Pública, Tapachula, Chiapas, México.
  • Rodriguez AD; Instituto Nacional de Salud Pública, Centro Regional de Investigación en Salud Pública, Tapachula, Chiapas, México.
  • Penilla-Navarro RP; Instituto Nacional de Salud Pública, Centro Regional de Investigación en Salud Pública, Tapachula, Chiapas, México.
  • Sanchez D; El Colegio de la Frontera Sur, Unidad Tapachula, Tapachula, Chiapas, México.
  • Castillo-Vera A; El Colegio de la Frontera Sur, Unidad Tapachula, Tapachula, Chiapas, México.
  • Lopez-Solis AD; Instituto Nacional de Salud Pública, Centro Regional de Investigación en Salud Pública, Tapachula, Chiapas, México.
  • Vazquez-Lopez ED; Jurisdicción Sanitaria VII, Tapachula Chiapas, Antiguo Hospital General de Tapachula, Tapachula, Chiapas, México.
  • Lozano S; Centers for Diseases Prevention and Control, Arboviral Diseases Branch, Fort Collins, Colorado, United States of America.
  • Black WC; Colorado State University, College of Veterinary Medicine and Biomedical Sciences Department of Microbiology, Immunology and Pathology, Arthropod Borne and Infectious Diseases Laboratory, Fort Collins, Colorado, United States of America.
  • Saavedra-Rodriguez K; Colorado State University, College of Veterinary Medicine and Biomedical Sciences Department of Microbiology, Immunology and Pathology, Arthropod Borne and Infectious Diseases Laboratory, Fort Collins, Colorado, United States of America.
PLoS Negl Trop Dis ; 15(9): e0009746, 2021 09.
Article em En | MEDLINE | ID: mdl-34570792
ABSTRACT

BACKGROUND:

Insecticide use continues as the main strategy to control Aedes aegypti, the vector of dengue, Zika, chikungunya, and yellow fever. In the city of Tapachula, Mexico, mosquito control programs switched from pyrethroids to organophosphates for outdoor spatial spraying in 2013. Additionally, the spraying scheme switched from total coverage to focused control, prioritizing areas with higher entomological-virological risk. Five years after this strategy had been implemented, we evaluated the status and variability of insecticide resistance among Ae. aegypti collected at 26 sites in Tapachula. METHODOLOGY/PRINCIPAL

FINDINGS:

We determined the lethal concentrations at 50% of the tested populations (LC50) using a bottle bioassay, and then, we calculated the resistance ratio (RR) relative to the susceptible New Orleans strain. Permethrin and deltamethrin (pyrethroids), chlorpyrifos and malathion (organophosphates), and bendiocarb (carbamate) were tested. The frequencies of the substitutions V1016I and F1534C, which are in the voltage-gated sodium channel and confer knockdown-resistance (kdr) to pyrethroid insecticides, were calculated. Despite 5 years having passed since the removal of pyrethroids from the control programs, Ae. aegypti remained highly resistant to permethrin and deltamethrin (RR > 10-fold). In addition, following 5 years of chlorpyrifos use, mosquitoes at 15 of 26 sites showed moderate resistance to chlorpyrifos (5- to 10-fold), and the mosquitoes from one site were highly resistant. All sites had low resistance to malathion (< 5-fold). Resistance to bendiocarb was low at 19 sites, moderate at five, and high at two. Frequencies of the V1016I ranged from 0.16-0.71, while C1534 approached fixation at 23 sites (0.8-1). Resistance profiles and kdr allele frequencies varied across Tapachula. The variability was not associated with a spatial pattern at the scale of the sampling. CONCLUSION/

SIGNIFICANCE:

Mosquito populations respond to selection pressure at a focal scale in the field. Spatial variation across sites highlights the importance of testing multiple sites within geographical regions.
Assuntos

Texto completo: 1 Coleções: 01-internacional Contexto em Saúde: 2_ODS3 / 3_ND / 4_TD Base de dados: MEDLINE Assunto principal: Resistência a Inseticidas / Aedes / Inseticidas Limite: Animals País/Região como assunto: Mexico Idioma: En Revista: PLoS Negl Trop Dis Ano de publicação: 2021 Tipo de documento: Article

Texto completo: 1 Coleções: 01-internacional Contexto em Saúde: 2_ODS3 / 3_ND / 4_TD Base de dados: MEDLINE Assunto principal: Resistência a Inseticidas / Aedes / Inseticidas Limite: Animals País/Região como assunto: Mexico Idioma: En Revista: PLoS Negl Trop Dis Ano de publicação: 2021 Tipo de documento: Article