Received: 26 March 2020
Accepted: 16 April 2020
First Online: 6 May 2020
Ethics approval and consent to participate
: This study was approved by the Ethics Committee of Wuhan Children’s Hospital (Wuhan Maternal and Child Health Care Hospital # WHCH 2020005). Written informed parental/guardian consent and child assent (where appropriate) were obtained prior to enrollment in the study.
: Not applicable.
: The authors declare that they have no competing interests.