1 Mailman School of Public Health, Columbia University, New York, New York, United States of America, 2 Rollins School of Public Health, Emory University, Atlanta, Georgia, United States of America, 3 UNICEF Headquarters, New York, New York, United States of America, 4 UNICEF Bolivia, La Paz, Bolivia, 5 WaterAid, London, United Kingdom, 6 Liverpool School of Tropical Medicine, Liverpool, United...