DDT and pyrethroid resistance status and laboratory evaluation of bio-efficacy of long lasting insecticide treated nets against Culex quinquefasciatus and Culex decens in Ghana
Center for International Health, Department of Infectious Diseases and Tropical Medicine, Ludwig-Maximilians-Universität Munich, Germany; Department of Entomology and Wildlife, School of Biological Sciences, University of Cape Coast, Ghana; Bavarian Health and Food Safety Authority (LGL), Oberschleissheim, Germany; Noguchi Memorial Institute for Medical Research, University of Ghana, Ghana
Nuisance from Culex mosquitoes in Ghana has a serious negative impact on the standard of living in many urban communities. In addition, a perceived lack of efficacy of long lasting insecticide treated nets (LLINs) against nuisance mosquitoes contributes to their discontinued use. This again compromises malaria control, even if Anopheles species themselves would still be susceptible to the insecticides used. Control strategies involve pyrethroid insecticides but information on Culex mosquito susceptibility to these insecticides is limited. A nationwide survey was conducted to address this problem. In adults, susceptibility to permethrin, deltamethrin and DDT as well as enzyme activity and kdr mutation were determined. Cone and tunnel bioassay were also carried out to determine the efficacy of LLINs against the mosquitoes. Culex quinquefasciatus and Culex decens were identified in the study area. Higher deltamethrin and DDT resistance and relatively low permethrin resistance were observed in both species. High enzyme activities and kdr mutations were observed in C. quinquefasciatus but not in C. decens. However, reduced efficacy of LLINs was observed in both mosquito species. This adds up to the evidence of the spread of pyrethroid resistance in mosquitoes and its negative impact on control strategies. © 2015 Elsevier B.V.
chlorphenotane; cytochrome P450; deltamethrin; esterase; genomic DNA; glutathione transferase; insecticide; permethrin; pyrethroid; unspecific monooxygenase; bioassay; DDT; disease control; disease spread; enzyme activity; malaria; mosquito; pyrethroid; Anopheles gambiae; Article; bioassay; controlled study; Culex; Culex decens; Culex quinquefasciatus; enzyme activity; gene; gene mutation; Ghana; kdr gene; laboratory test; malaria control; nonhuman; polymerase chain reaction; urban population; Ghana; Culex decens; Culex pipiens quinquefasciatus