Post-COVID-19 condition in children: epidemiological evidence stratified by acute disease severity

Background: To determine the prevalence of pediatric Post-COVID-19 condition (PPCC), identify risk factors, and assess the quality of life in children with differing severities of acute COVID-19. Methods: During a prospective longitudinal study with a 1-year follow-up, we compared non-hospitalized (mild) and hospitalized (severe) COVID-19 cases to a negatively tested control group. Results: 579 children were included in this study. Of these, 260 had mild acute disease (median age:8, IQR:6–10), 60 had severe acute disease (median age:1, IQR:0.1–4.0), and 259 tested negative for SARS-CoV-2 (NT) (median age:8, IQR:5-10). At three months, 14.6% of the SARS-CoV-2 positive mild group (RR:6.31 (CI 95%: 2.71–14.67)) and 29.2% of the severe group (RR:12.95 (CI 95%: 5.37–31.23)) reported sequelae, versus 2.3% of the NT group. PPCC prevalence in the mild group decreased from 16.1% at one month to 4.4% at one year. Children with PPCC exhibited lower physical health-related quality of life scores and higher fatigue scores than the NT children. Conclusions: Severe acute COVID-19 in children leads to a higher PPCC prevalence than in mild cases. PPCC prevalence decreases over time. Risk factors at three months include prior medical history, hospital admission, and persistent fatigue one month after a positive test. Impact: We demonstrate children with severe COVID-19 are more likely to develop Post-COVID-19 condition than those with mild or no infections, and highlights the risk factors. Here we have stratified by acute disease severity, prospectively included a negative control group, and have demonstrated the heterogeneity in prevalence when utilizing various recent definitions of post-COVID. Identifying risk factors for pediatric post-COVID and highlighting the heterogeneity in prevalence based on various current definitions for post-COVID should aid in correctly identifying potential pediatric post-COVID cases, aiding in early intervention.