1. Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
2. Social and Behavioral Interventions Program, Department of International Health, Room E5033, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore, MD 21205, USA
3. Department of Medicine, University of North Carolina, Chapel Hill, NC 27599, USA
4. Instituto de Estudios en Salud, Sexualidad y Desarrollo Humano, Universidad Peruana Cayetano Heredia, Lima, Peru
5. Department of Medicine, State University of New York at Buffalo, Buffalo, NY 14214, USA
6. Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, ON L8S 4L8, Canada
7. Department of HIV/AIDS, World Health Organization, 1211 Geneva, Switzerland