1. Department of Infectious Diseases, The Fourth Affiliated Hospital of Harbin Medical University, Harbin, China.
2. Department of Epidemiology and Health Statistics, Public Health College of Jilin Medical University, Jilin, China.
3. Department of Infectious Diseases, Changchun Infectious Disease Hospital, Changchun, China.
4. Department of Microbiology, Harbin Medical University, Harbin, China.
5. Department of Infectious Diseases, The Third People's Hospital of Shenzhen, Shenzhen, China.