1. Sociomedical Sciences, Columbia University Mailman School of Public Health, New York, NY, USA
2. Heilbrunn Department of Population and Family Health, Columbia University Mailman School of Public Health, New York, NY, USA
3. Department of Pediatrics, Columbia University Medical Center, New York, NY, USA
4. Morgan Stanley Children's Hospital, New York-Presbyterian Hospital, New York, NY, USA
5. Population Council, Washington, DC, USA
6. Rakai Health Sciences Program, Kalisizo, Uganda