Monitoring of Insecticides

Monitoring of insecticides resistance in malaria vector (s) in Pakistan

The development of resistance against insecticides is the major threat to any program which relies on use of chemicals. It is important to know when a vector species develop resistance in order to decide the most appropriate resistance management strategies such as interruption of spraying, change of insecticides or rotation of insecticides, or by other means. Since the eradication era during early 1960ā€™s, Pakistan implemented vector control interventions very successfully depending on the use of chemicals, with indoor residual house spraying as the main intervention. Since 1995 Pakistan is continuously using pyrethoroids while in many part of the world the resistance in malaria vectors against pyrethroids has been reported. Despite this fact there has been no systematic effort to monitor the level of resistance in malaria vectors against insecticides in the country since 1990ā€™sā€™ due to lack of expertise and updated knowledge on vector (s). Directorate of Malaria Control (DoMC) developed this project for monitoring of insecticides resistance in malaria vector (s) to all four groups of insecticides i.e. Pyrethroids (Permethrin, 0.75%), Organochlorinated Hydrocarbon (DDT, 4%), Carbamate (Bendiocarb,0.1%), and Organophosphate (Malathion 5%). The trials will be conducted at 8 sentinel sites according to WHO guidelines. Both unfed and F-1 generation females anophelines will be used in susceptibility tests. The exposure time will 1 hrs. with exception that in case of Deltamethrin 0.05% and Permethrin 0.75% the exposure time will be 30 minutes. The exposure tubes will be kept +90F and relative humidity 70-80%. Mortalities will be recoded after 24 hrs. of hold periods. In long term it is expected that the results from this study will generate up-graded knowledge of resistance in malaria vectors against insecticides. The final recommendations of the study will also enable the national health planners and policy makers to make better informed decisions and design more effective resistance management strategies, including switching over from one group of insecticides to new one or rotation of insecticides groups, regular operational research and capacity building program. These recommendations will also provide guidelines for judicious and rational use of residual insecticides for future vector control.