1. a Department of International Health , Johns Hopkins University Bloomberg School of Public Health , Baltimore , Maryland
2. b Rakai Health Sciences Program , Rakai District, Uganda
3. c Institute of Public Health , Kampala , Uganda
4. e School of Medicine , Makerere University , Kampala , Uganda
5. f Bloomberg School of Public Health, Department of Population and Family Health Sciences , John Hopkins University , Baltimore , Maryland
6. d Mailman School of Public Health, Center for Population and Family Health , Columbia University , New York