Zhuhai Center for Disease Control and Prevention, University of North Carolina (UNC) at Chapel Hill - Project-China, University of North Carolina (UNC) at Chapel Hill - Project-China, University of North Carolina (UNC) at Chapel Hill - Project-China, Zhuhai Xutong Voluntary Services Center, Alfred Health - Melbourne Sexual Health Centre, Southern Medical University, University of North Carolina (UNC) at Chapel Hill - Department of Health Policy and Management, University of North Carolina (UNC) at Chapel Hill - Project-China, Zhuhai Center for Disease Control and Prevention, Zhuhai Center for Disease Control and Prevention, University of North Carolina (UNC) at Chapel Hill - Project-China, University of North Carolina (UNC) at Chapel Hill - Project-China, University of North Carolina (UNC) at Chapel Hill - Project-China, University of North Carolina (UNC) at Chapel Hill - Project-China, University of North Carolina (UNC) at Chapel Hill - Project-China, Peking University - Clinical Research Academy, Zhuhai Center for Disease Control and Prevention, Zhuhai Center for Disease Control and Prevention, University of North Carolina at Chapel Hill - Department of Biostatistics, Dermatology Hospital of Southern Medical University, Dermatology Hospital of Southern Medical University, Zhuhai Center for Disease Control and Prevention and University of North Carolina Project-China