Indication of pyrethroid resistance in the main malaria vector, Anopheles stephensi from Iran

OBJECTIVE: To investigate insecticide resistance in target species for better insecticide resistance management in malaria control programs. METHODS: The status of insecticide resistance to different imagicides in Anopheles stephensi (An. stephensi) including DDT 4%, lambdacyhalothrin 0.50%, deltamethrin 0.05%, permethrin 0.75%, cyfluthrin 0.15% and etofenprox 0.50% was performed according to WHO standard method. RESULTS: The mortality rate to lambdacyhalothrin, permethrin, cyfluthrin, deltamethrin, etofenprox and DDT was (88.0 ± 3.2), (92.0 ± 2.7), (52.0 ± 5.0), (96.0 ± 2.2), (90.0 ± 3.0) and (41.0 ± 5.7) percent, respectively at diagnostic dose for one hour exposure time followed by 24 h recovery period. CONCLUSIONS: These results showed first indication of pyrethroid resistance in An. stephensi in a malarious area, from southern Iran. There is widespread, multiple resistances in the country in An. stephensi to organochlorine and some report of tolerance to organophosphate insecticides and recently to pyrethroids. However, results of this paper will provide a clue for monitoring and mapping of insecticide resistance in the main malaria vector for implementation of any vector control.