1. International Centre for Diarrhoeal Disease Research, Dhaka 1000, Bangladesh
2. The Population Council, One Dag Hammarskjold Plaza, New York, New York 10017
3. Maternal and Child Epidemiology Unit, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, United Kingdom
4. United Nations Development Programme, Kinshasa, Zaire