The conventional dosages of pyrethroid insecticides on mosquito nets assume that nets will be retreated at 6-12 month intervals.
However, dosage should be related to washing of nets ; if nets are only washed once or twice a year, their dosage requirements will be different to those which are washed fortnightly.
A'low-dose, frequent-wash'retreatment system might be technically more appropriate and more affordable where nets are washed frequently, as they are in Dar es Salaam.
Moreover, for use as a domestic insecticide, water-based formulations of pyrethroid are preferable to the more commonly used emulsifiable concentrates (ECs).
This paper reports laboratory evaluations of three formulations (ECs, Flowable, CS) of three pyrethroids (deltamethrin, lambdacyhalothrin, permethrin).
Insecticidal activity was tested using serial bioassays at a range of dosages using Anopheles gambiae.
The water-based formulations were no less effective than the ECs, even at the lowest dosages.
Nets treated with 3 mg/m2 and then repeatedly washed and retreated after each wash with either 3 mg/m2 or 1 mg/m2 were subjected to gas chromatography analysis.
This showed that the amounts of pyrethroid in the nets accumulated rapidly over the first few wash-retreatment cycles and then remained fairly stable over subsequent cycles. (...)
Mots-clés Pascal : Stratégie, Imprégnation, Insecticide, Pesticide, Pyréthrinoïde, Vecteur, Paludisme, Protozoose, Parasitose, Infection, Lutte phytosanitaire, Tanzanie, Afrique, Moustiquaire
Mots-clés Pascal anglais : Strategy, Impregnation, Insecticide, Pesticides, Pyrethroids, Vector, Malaria, Protozoal disease, Parasitosis, Infection, Pest and disease control, Tanzania, Africa
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 99-0262604
Code Inist : 002A37A. Création : 16/11/1999.