1. Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
2. U.S. Agency for International Development, Washington, District of Columbia.
3. ICF Macro, Beltsville, Maryland.
4. School of Public Health, Georgia State University, Atlanta, Georgia.
5. Instituto Nacional de Estadística e Informática, Lima, Peru.