1. Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
2. NGO Via Libre
3. Epidemiology, HIV and STD Unit, School of Public Health, Universidad Peruana Cayetano Heredia
4. Department of Microbiology, School of Science, Universidad Peruana Cayetano Heredia, Lima, Peru
5. Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA