ABSTRACT
Schistosomiasis (Bilharziasis) is a parasitic infection of various mammals including man and domestic livestock, caused by ‘blood-flukes’ of the genus Schistosoma. Two hundred million people are estimated to be infected and a further 500-600 million people at risk (Doumenge et al., 1987; World Health Organisation, 1993). The most extensive areas of infection are in Africa, China and the neotropics. A comprehensive general account of schistosomiasis is provided by Jordan & Webbe (1982) and Jordan et al. (1993); particular aspects of the biology of the parasites and hosts are considered in specialised reviews (Loker, 1983; Rollinson & Simpson, 1987; Basch, 1991).
