1. Department of Infectious Diseases, Chongqing Public Health Medical Center, Chongqing 400036, China
2. Center for Infectious Diseases, Beijing Youan Hospital, Capital Medical University, Beijing 100069, China
3. Department of Infectious Diseases, Liuzhou People's Hospital, Liuzhou 545006, Guangxi, China
4. Department of Infectious Disease, The Public Health Clinical Center of Chengdu, Chengdu 610066, Sichuan, China
5. Department of Infectious Disease, Guiyang Public Health Clinical Center, Guiyang 550004, Guizhou, China.