Funding for this research was provided by:
National Natural Science Foundation of China (81273137, 81773493, 81573211)
the National Key S&T Special Projects on Major Infectious Diseases (2012ZX10002)
Beijing Municipal Science & Technology Project (D141100000314001)
Received: 15 November 2018
Accepted: 10 June 2019
First Online: 22 June 2019
Ethics approval and consent to participate
: This study and all of the relevant experiments have been approved by the Ethical Board of the Beijing Institute of Microbiology and Epidemiology. All of the patients provided written informed consent, and the data were analyzed anonymously.
: Not applicable.
: The authors declare that they have no competing interests.