1. Department of Epidemiology, School of Public Health, and the Key Laboratory of Public Health Safety of Ministry of Education, Fudan University
2. Xuhui District Center for Disease Control and Prevention, Shanghai
3. Taizhou City Center for Disease Control and Prevention
4. Linhai District Center for Disease Control and Prevention
5. Sanmen District Center for Disease Control and Prevention
6. Wenlin District Center for Disease Control and Prevention
7. Huangyan District Center for Disease Control and Prevention, Zhejiang Province, China.