1. Behavioral Sciences and Health Education, Emory University, Atlanta, Georgia, USA
2. Institute for Global Health and Sexually Transmitted Diseases Research, Southern Medical University, Guangzhou, China
3. University of North Carolina Project-China, Guangzhou, China
4. Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
5. London School of Hygiene and Tropical Medicine, London, UK
6. Department of Public Health, Xi’an Jiaotong-Liverpool University, Suzhou, China
7. School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
8. Dermatology Hospital, Southern Medical University, Guangzhou, China