Zheng, Huizhen
Jia, Katherine Min
Sun, Riyang
Hu, Pui
Wang, Maggie Haitian
Zee, Benny Chung-Ying
Liang, Wenjia
Chong, Ka Chun http://orcid.org/0000-0001-5610-1298
Funding for this research was provided by:
Shenzhen Municipal Science and Technology Program (JCYJ20150630165236958)
National Natural Science Foundation of China (81473035, 71974165)
Article History
Received: 23 February 2019
Accepted: 26 February 2020
First Online: 6 March 2020
Ethics approval and consent to participate
: This study was reviewed and approved by the Medical Ethics Committee of the Guangdong CDC. Informed consent was waived by the Committee, as the data were collected for the purpose of routine public health surveillance activities. The data were anonymized before analysis.
: Not applicable.
: All authors declare that they have no competing interests.