1 Division of Infectious Diseases and Global Public Health, School of Medicine, University of California San Diego, La Jolla, CA 92093, USA. Electronic address: kdube@health.ucsd.edu.
2 Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada; Center for Interdisciplinary Research in Sexuality, AIDS and Society, Universidad Peruana Cayetano Heredia, Miraflores, Lima, Peru.