Permethrin-treated chaddars and top-sheets: appropriate technology for protection against malaria in Afghanistan and other complex emergencies

Insecticide-treated mosquito nets (ITN) provide excellent protection agains t malaria; however, they have a number of shortcomings that are particularl y evident in politically unstable countries or countries at war: not everyo ne at risk can necessarily afford a net, nets may be difficult to obtain or import, nets may not be suitable for migrants or refugees sleeping under t ents or plastic shelter. There is a need to develop cheaper, locally approp riate alternatives for the most impoverished and for victims of complex eme rgencies. Afghan women, in common with many Muslim peoples of Asia, wear a veil or wrap known as a chaddar to cover the head and upper body. This clot h doubles as a sheet at night, when they are used by both sexes. A randomiz ed controlled trial was undertaken in which 10% of the families of an Afgha n refugee camp (population 3950) in north-western Pakistan had their chadda rs and top-sheets treated with permethrin insecticide at a dosage of 1 g/m( 2) while a further 10% had their chaddars treated with placebo formulation. Malaria episodes were recorded by passive case detection at the camp's hea lth centre. From August to November the odds of having a falciparum or viva x malaria episode were reduced by 64% in children aged 0-10 years and by 38 % in refugees aged <20 years in the group using permethrin-treated chaddars and top-sheets. Incidence in refugees over 20 years of age was not signifi cantly reduced. The cost of the permethrin treatment per person protected ( US$0.17) was similar to that for treating bednets (and cost only 10-20% of the price of a new bednet). An entomological study simulating real-life con ditions indicated that host-seeking mosquitoes were up to 70% less successf ul at feeding on men sleeping under treated chaddars and some were killed b y the insecticide. Permethrin-treated top-sheets and blankets should provid e appropriate and effective protection from malaria in complex emergencies. In Islamic and non-Islamic countries in Asia, treated chaddars and top-she ets should offer a satisfactory solution for the most vulnerable who cannot afford treated nets.