Posted: 24 January 2001

A tropical or subtropical intestinal disease of humans caused by parasitic flatworms or flukes. Using snails as intermediate hosts, the flukes are spread from person to person through polluted water and insanitary living habits. Deteriorating health and reduced resistance usually cause those infected to die of secondary diseases rather than schistosomiasis itself. Schistosomiasis is prevalent in Africa, South America and tropical Asia, where as many as 200 million people are infected.