VARIOUS PYRETHROIDS ON BEDNETS AND CURTAINS

Verandah trap huts in a Tanzanian village were used to assess the effe ctiveness of impregnated bednets and curtains in preventing hut entry and feeding by, and in killing of Anopheles gambiae and An. funestus. Permethrin, deltamethrin, lambdacyhalothrin and pyrethrum were used fo r impregnation of damaged or undamaged bednets, sisal eaves curtains o r bed curtains made of polypropylene fibre. The performance of the thr ee synthetic pyrethroids did not differ statistically significantly, e xcept that on a damaged net permethrin was better at preventing feedin g. Sisal eaves curtains deterred mosquitoes from hut entry but did not kill those that had entered. In assessing damaged nets and curtains i t must be recognised that anything less than the best vector control m ay have no appreciable impact on holoendemic malaria.