1. College of Public Health, Zhengzhou University, Zhengzhou, Henan, China
2. Preventive Health Care Department, Zhaoxiang Town Community Health Service Center, Qingpu District, Shanghai, China
3. Anyang Center for Disease Control and Prevention, An Yang, Henan, China
4. College of Public Health and, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China