Received: 30 May 2021
Accepted: 4 November 2021
First Online: 22 December 2021
: The study was approved by the Ethics Committee in the National Institute of Parasitic Diseases, China CDC. The objectives, procedures and potential risks of this study were orally explained and informed to all participants. A written consent form was also obtained with signature of the participant or his/her guardian for a child.
: Not applicable.
: Xiao-Nong is an Editor-in-Chief of the journal <i>Infectious Diseases of Poverty.</i> He was not involved in the peer-review or handling of the manuscript. The authors have no other competing interests to disclose.