Funding for this research was provided by:
China-U.S. Collaborative Program on Emerging and Re-emerging Infectious Diseases (5U2GGH000961-04)
the Chinese Ministry of Science and Technology Program for Important Infectious Diseases Control and Prevention (2017ZX10105015)
Received: 7 May 2019
Accepted: 16 July 2020
First Online: 25 July 2020
Change Date: 21 December 2020
Change Type: Correction
Change Details: An amendment to this paper has been published and can be accessed via the original article.
Ethics approval and consent to participate
: The China CDC Ethical Review Committee approved the project as a program evaluation. The United States Centers for Disease Control and Prevention approved the project as a routine surveillance activity. We maintained all project related data on a secure and password protected computer.
: Not applicable.
: We do not have any known conflicts of interest associated with this publication. There is no significant financial support for this work that could have influenced its outcome.