Schistosomiasis is widely recognized as a disease that is socially determined. An understanding of the social and behavioural factors linked to disease transmission and control should play a vital role in designing policies and strategies for schistosomiasis prevention and control. To this must be added the awareness that schistosomiasis is also a disease of poverty. It still survives in poverty-stricken, remote areas where there is little or no safe water or sanitation, and health care is scarce or non-existent. For a variety of complex reasons, many of which are addressed in this book, the disease is particularly prevalent in sub-Saharan Africa, and persists in certain areas of rural China. This concern for human behaviour in an environment of poverty echoes the concerns of the new research priority for “diseases of poverty” identified by the Special Programme for Research & Training in Tropical Diseases.