Department of Epidemiology and Biostatistics Key Laboratory of Environment and Health of Ministry of Education School of Public Health Tongji Medical College Huazhong University of Science and Technology Wuhan 430030 China;
Department of Preventive Medicine School of Medicine Ningbo University Ningbo 315211 China;
Institute of Infectious Disease Control and Prevention Hubei Provincial Center for Disease Control and Prevention Wuhan 430079 China;