THE EFFECT OF PERMETHRIN-IMPREGNATED SISAL CURTAINS ON VECTOR DENSITYAND MALARIA INCIDENCE - A PILOT-STUDY

Impregnation of bednets and curtains with suitable pyrethroids may red uce entomological inoculation rates (EIR) and malaria incidence. We co nducted a quasi-experimental pilot study over 3 months in Western Keny a on 20 houses with 54 children. Ten houses in the experimental site r eceived sisal curtains treated with permethrin at either 0.5g/m2 or 0. 1g/m2. Control houses had untreated curtains or none. Mosquito vector density (MVD), man biting rates (MBR), and residual insecticidal effec ts (REE) of permethrin were determined every two weeks. MVD was reduce d by 97.7% and 98.7% in houses from the 2 experimental groups with a 6 0% reduction with unimpregnated curtains. MBR varied from 6.4 (no curt ains), 1.7 (unimpregnated), 0.7 (0.5g/M2 curtains) to 0.4 (1.0g/m2 cur tains). RIE begun to decline after the fourth month. Malaria incidence remained similar at the two sites. We conclude that covering of eaves and windows with permethrin impregnated sisal curtains can reduce MVD and the number of mosquito bites to individuals sleeping in protected houses.