1. Guangdong Provincial Center for Skin Disease and STI Control, Guangzhou, Guangdong 510091, China
2. School of Public Health, Sun Yat-sen University, Guangzhou, Guangdong 510085, China
3. Kirby Institute, The University of New South Wales, Sydney, NSW 2052, Australia
4. Guangdong Pharmaceutical University, Guangzhou, Guangdong 511430, China
5. University of North Carolina Project-China, Guangzhou, Guangdong, 510091, China