Natural course and risk factors for complications

Pediatrics | 479

4th, 2020; only 128 were admitted to 66 hospitals, only one child died (Armann 2020). The European Surveillance System (TESSy) collects data from EU/EEA countries and the UK on laboratory-confirmed cases of COVID-19. Out of 576,024 laboratory confirmed COVID-19 cases 0,7% were 0-4 years, 0,6% 5-9 years, 0,9% 10-14 years (https://covid19-surveillance-report.ecdc.europa.eu). The multicentre cohort study (82 participating health-care institutions across 25 European countries), Paediatric Tuberculosis research Network (ptbnet) confirmed that COVID-19 is generally a mild disease in children. Of 582 children and adolescents (median age 5.0 years, 25% with pre-existing conditions) with PCR-confirmed SARS-CoV-2 infection, 363 (62%) were admitted to hospital and 48 (8%) required ICU admission. Significant risk factors for requiring ICU admission in multivariate analyses were being younger than 1 month (odds ratio 5.1), male sex (2.1) and pre-existing medical conditions (3.3). Four children died (Götzinger 2020).

The incubation period is believed to be 3-7 days (range 1-14 days) (She 2020), the clinical onset 5-8 days after infection with the virus. Children often have an asymptomatic or less severe COVID-19 disease course than adults (Zimmermann 2020, Parri 2020). Among a total of 100 children with SARSCoV-2 from Italy, 21% were asymptomatic, 58% had mild disease, 19% had moderate disease, 1% had severe disease, and 1% were in critical condition (Parri 2020). Due to the paucity of data it is as yet unclear which group of children may be at a higher risk for development of complications, e.g. children with underlying chronic pulmonary or cardiac disease, severe neurologic deficits, immunosuppressed or critically ill children, etc. Analogous to influenza there might be genetic susceptibility in some children (see below, pathophysiology, Clohisey 2019). Interestingly, in a flash survey from 25 countries with 10,000 children with cancer at risk and 200 tested, only 9 were found to be CoV-2 positive. They were asymptomatic or had mild disease (Hrusak 2020). Even in the severely immunosuppressed and in children with significant cardiac and pulmonary comorbidities COVID-19 can be overcome (Dinkelbach 2020). In The European Surveillance System (TESSy) deaths among children aged below 15 years are rare, 4 out of 44,695 (0.009%) were reported. The rate of hospitalization was higher in children under the age of five especially in infants compared to persons aged 5-29. However, it is believed that the threshold for admission is lower in young children. A severe course requiring ad-