Sichuan University - West China School of Public Health, Nanjing Medical University, Sichuan University, Yulin Community Health Service Center, Yale University, National University of Singapore (NUS) - Duke-NUS Medical School, Alfred Health - Melbourne Sexual Health Centre, Sichuan University, Sichuan University, Peking University - Institute of Population Research, The Bill & Melinda Gates Foundation - Beijing Representative Office, The Bill & Melinda Gates Foundation - Beijing Representative Office, University of North Carolina (UNC) at Chapel Hill, London School of Hygiene & Tropical Medicine - Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine - Centre for Mathematical Modelling of Infectious Diseases, London School of Hygiene & Tropical Medicine - Department of Infectious Disease Epidemiology, University of North Carolina (UNC) at Chapel Hill, Washington University in St. Louis, Southern Medical University - Acacia Labs of SMU Institute for Global Health (SIGHT), University of North Carolina Project-China, Duke University - Duke Global Health Institute, University of North Carolina (UNC) at Chapel Hill - Division of Infectious Disease and London School of Hygiene & Tropical Medicine - Department of Clinical Research