1 State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China.
2 Beijing Center for Disease Control and Prevention, Beijing 100013, China.
3 Beijing Center for Disease Control and Prevention, Beijing 100013, China. Electronic address: bjcdcxm@126.com.
4 State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China. Electronic address: zhangjianzhong@icdc.cn.