Abstract

not-yet-known not-yet-known not-yet-known unknown Objective: To investigate the prevalence of clinical manifestations of post COVID-19 condition, also known as long COVID, in children hospitalized with COVID-19. Methods: This is a systematic review of observational studies. We conducted the search on the databases of PUBMED and EMBASE (up to March 15, 2023). We used the following search strategy: ”long COVID” OR ”post COVID-19” OR ”post-acute COVID-19” OR ”long-term COVID” OR ”COVID-19 sequelae” OR ”persistent COVID-19” OR ”chronic COVID-19”. We included observational studies (case-control, cross-sectional, cohort, or case series) that investigated the clinical manifestations of post COVID-19 condition in children (<18 years) admitted with COVID-19. We used the WHO case definition of post COVID-19 condition (ICD-10 U09). Four authors independently assessed the studies. We performed the meta-analysis of prevalence using a random-effects model. Results: Eleven studies involving 2279 patients were included. In the period between ≥3 months and <12 months after acute COVID-19, the most frequent symptom was exercise intolerance with a pooled prevalence of 29% (95% CI: 7-57%), followed by nonspecific respiratory symptoms (12%, 95% CI: 0-48%) and nonspecific gastrointestinal symptoms (10%, 95% CI: 0-37%). In the period ≥12 months after the initial infection, the pooled prevalence of post COVID symptoms was lower, with 6% (95% CI: 2-10%) for exercise intolerance and 3% (95% CI: 0-8%) for fatigue. Conclusions: Clinical manifestations of post COVID condition in hospitalized children include symptoms across multiple organ systems, with higher prevalence in the period up to 12 months after the acute phase of COVID-19.