1. Clinical and Research Center of Infectious Diseases, Beijing Ditan Hospital, Capital Medical University , Beijing , China
2. Institute of Infectious Diseases, Beijing Ditan Hospital, Capital Medical University , Beijing , China
3. Beijing Key Laboratory of Emerging Infectious Diseases, Institute of Infectious Diseases, Beijing Ditan Hospital, Capital Medical University , Beijing , China
4. National Center for Infectious Diseases, Beijing Ditan Hospital, Capital Medical University , Beijing , China