1. Center of Infectious Diseases, West China Hospital of Sichuan University, Chengdu, China
2. Laboratory of Infectious and Liver Diseases, Institution of Infectious Diseases, West China Hospital of Sichuan University, Chengdu, China
3. West China School of Public Health, Sichuan University, Chengdu, China
4. West China School of Medicine, Sichuan University, Chengdu, China
5. National Center for Birth Defect Monitoring, Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, West China Second University Hospital, Chengdu, China