Funding for this research was provided by:
Received: 11 June 2020
Accepted: 19 November 2020
First Online: 25 November 2020
Ethics approval and consent to participate
: All participating households gave their written consent for their participation in the study. This study received approval from the Ethics Committee of the School of Public Health at Zhejiang University (No. ZGL201803–1).
: Not applicable.
: The authors declare that they have no competing interests.