1. Division of Global HIV and Tuberculosis, Centers for Disease Control and Prevention , Atlanta, Georgia , USA
2. National Center for HIV/AIDS, Dermatology, and STDs, Cambodia Ministry of Health , Phnom Penh , Cambodia
3. Division of Global HIV and Tuberculosis, Centers for Disease Control and Prevention , Phnom Penh , Cambodia
4. Institute for Global Health Sciences, University of California San Francisco , San Francisco, California , USA