1. Department of Global Health and Population, Harvard School of Public Health, Boston, MA
2. Department of Nutrition, Harvard School of Public Health, Boston, MA
3. Division of Gastroenterology and Nutrition, Boston Children's Hospital and Harvard Medical School, Boston, MA
4. Department of Microbiology and Immunology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
5. UNICEF Headquarters, New York, NY
6. Department of Paediatrics and Child Health, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
7. Department of Epidemiology, Harvard School of Public Health, Boston, MA