Resistance Status of Anopheles maculipennis and Anopheles superpictus to the Conventional Insecticides in Northeastern Caspian Littoral, Iran

Abstract

Background: Malaria resurgence has occurred in the northern half parts of Iran. Factors such as the continual move­ment of local people from problematic malaria foci in southeastern Iran toward the Caspian Littoral and wide use of pesticides in the agriculture sector were led to establish the diseases in the prone area. There are no new data on the re­sistance status of main malaria vectors in the Caspian Littoral, and this study was aimed at renewal data on conventional insecticides. Methods: The field strain of adult Anopheles superpictus and Anopheles maculipennis were collected using the hand catch method and transferred to the laboratory. The susceptibility tests were carried out against DDT 4%, Malathion 5%, Permethrin 0.75%, Deltamethrin 0.05%, and Lambda-cyhalothrin 0.05%, followed by the WHO’s procedure. Results: The primary malaria vector in Caspian Littoral is An. maculipennis, which still resistance to DDT and mortali­ty rate, LT50 and LT90 of female mosquitoes were 75.0%, 54.2, minutes and 111.3 minutes. The under ’verification re­quired’ status of An. maculipennis was also revealed to Lambda-cyhalothrin based on recent WHO’s criteria. The ma­laria vector An. superpictus is also considered the second malaria vectors in the west parts of the studied area, which shown to be susceptible to all insecticides tested. Conclusion: DDT resistance is persisted in An. maculipennis despite stopping residual spraying with DDT since 1978 in the Caspian Littoral, but the occurrence of pyrethroid under ’verification required’ status is a progressive threat to the possible development of cross-resistance in the future.

Keywords

• Anopheles maculipennis; Anopheles superpictus; Insecticide resistance; Malaria; Caspian Littoral