Funding for this research was provided by:
Korea Centers for Disease Control and Prevention (2014ER270502)
Received: 19 February 2020
Accepted: 8 June 2020
First Online: 17 June 2020
Ethics approval and consent to participate
: The present study was approved by the institutional reviews board (IRB) of Sungkyunkwan University (IRB no. 2018–10-020).
: Not applicable.
: The authors declare that they have no competing interests.