The Behavioral Determinants of Intestinal Schistosomiasis Transmission: Water Contact, Hygienic Practices and Risk Prevention. A study in Northern Senegal

Schistosomiasis (bilharzia) is one of the major parasitic diseases in the world, ranking second only to malaria in terms of its socio-economic and public health importance in tropical and subtropical areas (WHO, 1985; WHO, 2002). At least 200 million people are infected and 600 million at risk. An estimated 85% of all cases occur in Africa. Schistosomiasis is caused by infection with blood-dwelling fl uke worms (trematodes) of the genus Schistosoma. These are transmitted by fresh water snails and contracted through the skin during water contact. Humans can be infected by fi ve different species of the parasite, each of which has its own characteristics and effects. Except where mentioned differently, this thesis considers S. mansoni, the parasite of intestinal schistosomiasis in Northern Senegal.