1. State Key Laboratory for Infectious Disease Prevention and Control, National Center for AIDS/STD Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China.
2. Sichuan Center for Disease Control and Prevention, Chengdu, People's Republic of China.
3. Guangdong Provincial Institute of Public Health, Guangzhou, People's Republic of China.
4. Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, People's Republic of China.