PYRETHROID-IMPREGNATED BED NETS FOR PERSONAL PROTECTION AGAINST MALARIA FOR AFGHAN REFUGEES

A field trial of permethrin-impregnated bed nets (PIBs) was conducted in 2 Afghan refugee villages in Pakistan. Nets were issued to only 10% of families (=1398 people); this simulated a situation in which bed n ets are gradually adopted by villagers in Afghanistan. A further 10% l acking bed nets were selected as controls from the same villages. An i nitial survey showed that 86% of household heads were aware that malar ia was transmitted by mosquito bites, but only 2% had used bed nets be fore. Trial families were encouraged to attend the village health cent res if they fell ill. Microscopy records showed that, between July and December 1991, 22.4% of the control group became infected with Plasmo dium vivax and 13.0% contracted P. falciparum while in the interventio n group only 9.9% contracted P. vivax (relative risk 0.58, confidence interval [CI] 95% 0.49-0.68) and only 3.8% contracted P. falciparum (r elative risk 0.39, 95% CI 0.29-0.53). A single treatment of the nets w ith permethrin at 0.5 g/m(2) remained protective throughout the 6 mont hs' transmission season. 73% of families claimed to use their nets eve ry night; members of families who claimed to use nets less regularly s howed an incidence similar to that of the control group. There was no sex or age difference in net use or protective efficacy. Headlouse inf estation rates were reduced in PIE users. Few nets were washed, given away or sold. The prospect for PIBs as personal protection appears goo d, despite people's lack of previous experience.