Helminth infections are caused by parasitic worms (including tapeworms and roundworms). These diseases are associated with poverty, and in school-age populations in developing countries, intestinal helminth infections rank first among the causes of all communicable and noncommunicable diseases. This book is based on papers presented at an OECD conference, held in Bali, Indonesia in February 2000, which sought to review activities for the control of diseases due to soil-transmitted helminth infections in Indonesia and neighbouring countries.