1. Department of Acute Infectious Diseases Control and Prevention Jiangsu Provincial Center for Disease Control and Prevention Nanjing China
2. NHC Key Laboratory of Enteric Pathogenic Microbiology Nanjing China
3. Department of Epidemiology and Health Statistics School of Public Health Southeast University Nanjing China
4. Huaian Center for Disease Control and Prevention Huaian China
5. Key Laboratory of Environmental Medicine Engineering Ministry of Education Nanjing China
6. School of Public Health Nanjing Medical University Nanjing China