Susceptibility Status of The Malaria Vector Anopheles Arabiensis To Insecticides in Khartoum State, Sudan

Abstract

Background: Increasing insecticide resistancein the major anopheline vectors remain the main obstacle for malaria control programmes in African countries including Sudan.

Objectives: To assess the susceptibility status of Anopheles arabiensis the malaria vector to different classes of insecticides in Khartoum State.

Materials and Methods: Using WHO procedure, susceptibility tests were conducted on adults of An.arabiensis from nine sentinel sites in Khartoum State. Mortality rates and knockdown times of insecticides for An. arabiensis were calculated.

Results: A total of 8345 females of An.arabiensis were tested againsteight insecticides, these wereDDT 4%, fenitrothion 1%, malathion 5%, propoxur 0.1%, permethrin 0.75%, deltamethrin 0.05% and lambdacyhalothrin 0.05%. Of these insecticides tested, An. arabiensis from Khartoum State wassusceptible to only fenitrothion 1% and lambdacyhalothrin 0.05% with overall mean percentage mortalities 99±0.12 and 100±0.45 respectively.In addition, the overall results, revealed a low mean mortality rates in An. arabiensis indicating resistance to the other remaining insecticides.Furthermore, all populations of An. arabiensis from different sentinel sites showed variation in mortality rates for the tested insecticides. The exception were for fenitrothion 1% and lambdacyhalothrin 0.05% which were resulted in 100% mean mortality in An. Arabiensis in each sentinel sites. Similarly, the knock down time (KDT) of all insecticide tested for 50% and 95% of An. arabiensis varied between populations of sentinel sites.

Conclusion: In conclusion, An. arabiensis the main malariavector in Khartoum State is mainly susceptible to fenitrothion and lambdacyhalothrin. Therefore, these two insecticides could be the more suitable for malaria vector control in Khartoum State.

Key Words: Anopheles arabiensis; susceptibility; KDT, Khartoum State, Sudan