Permethrin-impregnated bednets reduce nuisance arthropods in Gambian houses

The prevalence of bedbugs (Cimex hemipterus L.), chicken ticks (Argas persicus Oken) and headlice (Pediculus capitis De Geer) was surveyed in a rural area of The Gambia. At the beginning of the study 37.5% of children's beds were infested with bedbugs and 3.9% with chicken ticks, whilst the prevalence rate of pediculosis in children under 10 years old was 28.8%. Both bedbugs and headlice were clustered within compounds. Headlice prevalence increased with hair length and they were more common on girls than boys. Following this cross-sectional survey all bednets in the sixteen hamlets were either dipped in permethrin or a placebo. About 4 months later it was found that bedbugs and chicken ticks had disappeared from homes in which the bednets had been impregnated with permethrin. There was no reduction in hamlets with placebo-treated bednets. The rate of acquiring headlice between the two surveys was reduced by 91.1% in children who slept under insecticide-treated bednets compared with children with placebo-treated bednets. There were also significantly fewer day-flying and crawling insects, except earwigs, in homes of children who slept under insecticide-treated bednets compared with those with placebo-treated nets. These additional benefits of permethrin-treated bednets should contribute to their widespread acceptance and utilization by the community for personal protection.