1. NHC Key Laboratory of Enteric Pathogenic Microbiology, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, China
2. National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
3. Nanjing Infectious Diseases Clinical Medical Center (The Second Hospital of Nanjing, Nanjing University of Chinese Medicine), Nanjing, P.R China
4. Department of Epidemiology and Health Statistics, School of Public Health, Southeast University, Nanjing, China
5. School of Public Health, Nanjing Medical University, Nanjing, People’s Republic of China
6. Nanjing Municipal Center for Disease Control and Prevention, Nanjing, People’s Republic of China
7. Yangzhou Center for Disease Control and Prevention, Yangzhou, Pople's Republic of China
8. The Third People's Hospital of Yangzhou, Yangzhou, People’s Republic of China