1. School of Information and Mathematics, Yangtze University, Jingzhou 434023, Hubei, P. R. China
2. School of Mathematics, Beijing University of Technology, Beijing 100124, P. R. China
3. National Center for Respiratory Medicine, State Key Laboratory of Respiratory Health and Multimorbidity; National Clinical Research Center for Respiratory Diseases Institute of Respiratory Medicine, Chinese Academy of Medical Sciences, Department of Pulmonary and Critical Care Medicine, Center of Respiratory Medicine, China-Japan Friendship Hospital, Beijing, China
4. China-Japan Friendship Hospital (Institution of Clinical Medical Sciences), Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100029, P. R. China
5. National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing 100021, P. R. China
6. Division of Infectious Disease, Chinese Center for Disease Control and Prevention, Beijing 102206, P. R. China