1. Department of Infectious Diseases, the First Affiliated Hospital of Xi’an Jiaotong University, Xi’an 710061, China
2. Peking University Ditan Teaching Hospital, Beijing 100015, China
3. Beijing Key Laboratory of Emerging Infectious Diseases, Beijing 100015, China
4. Insitiute of Infectious Diseases, Beijing Ditan Hospital, Capital Medical University, Beijing 100015, China