1 Microbiology Laboratory, Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing 100045, China; Respiratory Department, Shenzhen Children's Hospital, Shenzhen 518038, China.
2 Pediatrics Department, Beijing Chaoyang Hospital affiliated to Capital Medical University, Beijing, China.
4 Microbiology Laboratory, Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing 100045, China; Respiratory Department, Shenzhen Children's Hospital, Shenzhen 518038, China. Electronic address: yyh628628@sina.com.