bifenthrin and Malaria--Falciparum

The efficacy of mosquito nets treated with bifenthrin (pyrethroid) and chlorpyrifos-methyl (organophosphate), alone and in mixture, was evaluated against the pyrethroid-resistant strain (VKPR) of Anopheles gambiae using the tunnel test technique. Results first showed that bifenthrin and chlorpyrifos-methyl kept a good excito-repellency effect against resistant mosquitoes despite the low doses applied on nets. With the mixture, irritancy significantly increased, which consequently limited the duration of exposure of females to impregnated surface. This phenomenon most probably explained the absence of synergism between bifenthrin and chlorpyrifos-methyl concerning the insecticidal activity of this mixture. This study demonstrated the importance of the mosquito behaviour in the global effectiveness of insecticide treated materials and in the development of alternative strategies for vector control. Concerning the prospective insecticide mixtures, not only will we have to consider the insecticidal properties of each insecticide selected, but also their excito-repellency which affects the time of duration of mosquitoes on the treated surface.

Topics: Animals; Anopheles; Bedding and Linens; Behavior, Animal; Chlorpyrifos; Cholinesterase Inhibitors; DDT; Drug Resistance, Multiple; Drug Synergism; Insect Vectors; Insecticide Resistance; Insecticides; Malaria, Falciparum; Mosquito Control; Protective Devices; Pyrethrins