[Resistance of Anopheles labranchiae to DDT in Morocco: identification of the mechanisms and choice of replacement insecticide].

A study of Anopheles labranchiae resistance in Morocco was conducted in the provinces of Kénitra, Khouribga, Larache, Khémisset and Salé during 2005. An. labranchiae was susceptible to propoxur, fenitrothion and permethrin and resistant to varying degrees to DDT. Genetically there was no change to the target site common to DDT and pyrethroids, the voltage gated sodium channel. The resistance seemed to be due to detoxification mechanisms specific to DDT. In principle, there should be no obstacle to the substitution of DDT by pyrethroids in Morocco. Resistance can then be detected and supervised by more reliable molecular tools in the Laboratory of Medical Entomology of the National Institute of Hygiene.