Control of Schistosoma mansoni transmission by provision of domestic water supplies. A preliminary report of a study in St Lucia.

As an experimental control measure to reduce the transmission of S. mansoni, an individual household water supply was provided in 400 houses in 5 rural settlements of the Riche Fond Valley, St Lucia. This population of about 2 000 had previously been dependent for water on infective streams and rivers. Six other settlements in the valley, all provided with limited piped water from public standpipes, served as the comparison area. After 2 years the incidence, prevalence, and intensity of infection with S. mansoni were significantly lower in the household water supply area, whereas all these indices of infection had increased in the comparison area. An adequate, reliable, and convenient supply of water can reduce the transmission of S. mansoni and should be considered as a control measure in other endemic areas.