Method
Prospective cohort with nested case-control study of all children tested by PCR for SARS-CoV-2 by nasopharyngeal/oropharyngeal sampling between March and October 2020. Children were identified prospectively via laboratory notification with age and sex-matching of SARS-CoV-2[+] to SARS-CoV-2[-] (1:2). Clinical data were extracted from the electronic medical record.