1. Teaching and Research Office of Epidemiology and Health Statistics, School of Public Health, Southeast University, Nanjing, China.
2. Department of Infectious Disease Prevention and School Health, Nanjing Municipal Center for Disease Control and Prevention, Nanjing, China.
3. Department of AIDS and STD, Shanghai Municipal Center for Disease Control and Prevention, Shanghai Municipal Institutes for Preventive Medicine, Shanghai, China.
4. School of Public Health, Nantong University, Nantong, China.