Funding for this research was provided by:
Science and Technology Plan Program of Guangzhou (No. 201803040012)
Key Area R&D Program of Guangdong Province (No. 2019B020227005)
National Key Research and Development Program of China (No.2017YFC1307603)
Received: 31 July 2020
Accepted: 6 October 2020
First Online: 15 October 2020
Ethics approval and consent to participate
: The survey protocol was approved by the Institutional Review Board of the Centers for Disease Control and Prevention (Protocol 98–12, 2005–06 and 2011–17). All patients received informed consent before the start of the study.
: All authors approved and agreed to publish the final version of the manuscript.
: The authors declare that they have no conflict of interest.