Review of prevalence and distribution of schistosomiasis in Japan.

There has been a temporary increase in schistosomiasis japonica after World War II in each of the known endemic areas, but a national control programme, including use of molluscicides, lining irrigation ditches through rice paddies with concrete and the reclamation of swampy areas by drainage and filling, begun around 1950, drastically reduced the prevalence and distribution of the disease. It can be said that these measures together with improvements in agricultural techniques, mechanization of farming and also socioeconomic factors such as improvements in the living standards of the inhabitants and urbanization have brought about a rapid decrease in schistosomiasis in Japan.