The incidence of bilharzia in the Durban area

The World Health Organization reviewing the problem of bilharziasis, commented: 'In recent years the prevalence of bilharziasis has shown an increase - an increase that is largely of man's own making, because, by the construction of dams, irrigation systems and other water conservation works in his attempts to relieve the problem of feeding the world's ever-growing population, he is creating the very conditions that favour the spread of the disease'.