1. Department of International Health, The Johns Hopkins School of Hygiene & Public Health, Baltimore, MD 21205
2. Ivo de Carneri Foundation, Milan, Italy
3. Schistosomiasis and Intestinal Parasites Unit, Division of Control of Tropical Diseases, World Health Organization, Geneva 27, Switzerland
4. Nepal Netra Jyoti Sangh, Kathmandu, Nepal
5. Ministry of Health, Zanzibar, United Republic of Tanzania