Review ArticlesHow Common is Long COVID in Children and Adolescents?Zimmermann, Petra MD, PhD*,†,‡,§; Pittet, Laure F. MD-PhD‡,§,¶; Curtis, Nigel FRCPCH, PhD‡,§,‖ Author Information From the *Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland †Department of Paediatrics, Fribourg Hospital HFR, Fribourg, Switzerland ‡Department of Paediatrics, The University of Melbourne, Parkville, VIC, Australia §Infectious Diseases Research Group, Murdoch Children’s Research Institute, Parkville, VIC, Australia ¶Pediatric Infectious Diseases Unit, Geneva University Hospitals and Faculty of Medicine, Geneva, Switzerland ‖Infectious Diseases Unit, The Royal Children’s Hospital Melbourne, Parkville, Australia. Accepted for publication August 17, 2021 The authors have no funding or conflicts of interest to disclose. P.Z. drafted the initial article. L.P. and N.C. contributed to the writing and critical revision of the article, and all authors approved the final article as submitted. Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal’s website (www.pidj.com) Address for correspondence: Petra Zimmermann, MD, PhD, Faculty of Science and Medicine, University of Fribourg, Route des Arsenaux 41, 1700 Fribourg, Switzerland. E-mail: [email protected]. The Pediatric Infectious Disease Journal 40(12):p e482-e487, December 2021. | DOI: 10.1097/INF.0000000000003328 Buy SDC Metrics Abstract In children, the risk of coronavirus disease (COVID) being severe is low. However, the risk of persistent symptoms following infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is uncertain in this age group, and the features of “long COVID” are poorly characterized. We reviewed the 14 studies to date that have reported persistent symptoms following COVID in children and adolescents. Almost all the studies have major limitations, including the lack of a clear case definition, variable follow-up times, inclusion of children without confirmation of SARS-CoV-2 infection, reliance on self- or parent-reported symptoms without clinical assessment, nonresponse and other biases, and the absence of a control group. Of the 5 studies which included children and adolescents without SARS-CoV-2 infection as controls, 2 did not find persistent symptoms to be more prevalent in children and adolescents with evidence of SARS-CoV-2 infection. This highlights that long-term SARS-CoV-2 infection–associated symptoms are difficult to distinguish from pandemic-associated symptoms. Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.