Public health is of central importance in the design and implementation of excreta disposal projects, and better health is the main social and economic benefit that planners and economists hope to gain by investing in excreta disposal systems. To achieve this gain as much information as possible is needed about the interactions between excreta and health - information not only about broad epidemiological issues of disease prevention through improved excreta disposal, but also about the effect of particular excreta disposal and reuse technologies on the survival and dissemination of particular pathogens. This book sets out to provide such information for a broad readership. It is intended for the wide spectrum of professionals concerned with sanitation and public health. The book has two parts. Part one, entitled "The Health Hazards of Excreta: Theory and Control, " presents a distillation of available knowledge about excreta, night soil, and sewage and their effects on health. Part two, entitled "Environmental Biology and Epidemiology of Specific Excreted Pathogens, " contains twenty eight chapters, each describing the environmental properties of a specific excreted pathogen or group of excreted pathogens and the epidemiology and control of the infections these pathogens cause.