Insecticide susceptibility of Anopheles stephensi to DDT and current insecticides in an elimination area in Iran.
Iran has recently initiated a malaria elimination program with emphasis on vector control strategies which are heavily reliant on indoor residual spraying and long-lasting insecticidal nets. Insecticide resistance seriously threatens the efficacy of vector control strategies. This study was conducted to determine the insecticide susceptibility of Anopheles stephensi to DDT and current insecticides in Jask county as an active malaria focus in southeastern Iran.



In this study, the anopheline larvae were collected from different aquatic habitats in Jask county and transported to insectarium, fed with sugar and then 3-day-old adults were used for susceptibility tests. WHO insecticide susceptibility tests were performed with DDT (4 %), malathion (5 %), lambda-cyhalothrin (0.05 %), deltamethrin (0.05 %) and permethrin (0.75 %).



The field strain of An. stephensi was found resistant to DDT and lambda-cyhalothrin. The LT50values for DDT and lambda-cyhalothrin in this species were 130.25, and 37.71 min, respectively. Moreover, An. stephensi was completely susceptible to malathion and permethrin and tolerant to deltamethrin.



The present study results confirm the resistance of the major malaria vector, An. stephensi, to DDT and lambda-cyhalothrin, and tolerance to deltamethrin, which could gradually increase and spread into other malaria endemic areas. Thus, there is a need for regular monitoring of insecticide resistance in order to select suitable insecticides for vector control interventions towards malaria elimination.
Department of Occupational Health Engineering, Faculty of Health, Hormozgan University of Medical Sciences, Bandar Abbas, Iran.
Mehdi
M
Zare
Social Determinants in Health Promotion Research Center, Hormozgan University of Medical Sciences, Bandar Abbas, Iran. mussa.soleimani@yahoo.com.|Department of Medical Entomology and Vector Control, Faculty of Health, Hormozgan University of Medical Sciences, P.O. Box: 79145-3838, Bandar Abbas, Iran. mussa.soleimani@yahoo.com.
Moussa
M
Soleimani-Ahmadi
Department of Nutrition Research, National Nutrition and Food Technology Research Institute, Faculty of Nutrition Sciences and Food Technology, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Sayed Hossein
SH
Davoodi
Social Determinants in Health Promotion Research Center, Hormozgan University of Medical Sciences, Bandar Abbas, Iran.|Department of Medical Entomology and Vector Control, Faculty of Health, Hormozgan University of Medical Sciences, P.O. Box: 79145-3838, Bandar Abbas, Iran.
Alireza
A
Sanei-Dehkordi
D000818:Animals; D000852:Anopheles; D003634:DDT; D007305:Insecticide Resistance; D007306:Insecticides; D007492:Iran / Q000453:epidemiology; D007814:Larva; D008288:Malaria / Q000453:epidemiology / Q000517:prevention & control; D008294:Malathion; D009032:Mosquito Control / Q000379:methods; D000072138:Mosquito Vectors; D009570:Nitriles; D026023:Permethrin; D011722:Pyrethrins
D007306:Insecticides; D009570:Nitriles; D011722:Pyrethrins; C017180:decamethrin; D026023:Permethrin; D003634:DDT; D008294:Malathion; C037304:cyhalothrin
Anopheles stephensi; Insecticide resistance; Iran; Jask; Malaria