Epidemiology of COVID-19 in children

478 | CovidReference.com

human coronaviruses. In many children there are co-infections with other viruses such as Adeno-, Boca-, Rhino-, RSV-, Influenza- or Parainfluenza virus. There seems to be a cyclical pattern with seasonal outbreaks between December and May or March to November in the southern hemisphere. Single-strand RNA coronaviruses are capable of mutation and recombination leading to novel coronaviruses that can spread from animals to humans. They have caused epidemics leading to significant case fatality rates (10% in SARSCoV, Hong Kong 2002; more than 30% in MERS-CoV, Saudi Arabia 2012). Because of the high case fatality rate, both SARS-COV and MERS-COV have a low potential for long-term sustained community transmission. Accordingly, no human SARS-CoV infections have been reported since July 2003. It is estimated that in SARS-CoV-2, one person infects 2-3 other persons. In clusters (e.g. nosocomial outbreaks) this number might be much higher. In both SARS-CoV and MERS-CoV, super-spreading events with one individual infecting up to 22 (SARS) or even 30 individuals (MERS) have been reported, especially in nosocomial outbreaks. In SARS-CoV a total of 41 children were reported with no deaths. Similarly, in MERS-CoV only 38 children were reported in two studies, with two deaths (Zimmermann 2020).

On April 6 the US CDC reported 2572 (1.7%) children under 18 years among 149,082 reported cases from 12 February to 2 April 2020. The availability of data was extremely limited (less than 10% available on symptoms, 13% on underlying conditions, 33% on whether children were hospitalized or not). Three deaths were reported to the CDC but no details were given. The median age was 11 and they were 57% males. 15 children were admitted to an ICU (≤ 2%). Children < 1 year accounted for the highest percentage (15-62%) of hospitalization (CDC 2020). The Chinese CDC report (Dong 2020) comprises 2143 pediatric patients from January 16 to February 8 2020. Only 731 children (34,1%) were laboratory confirmed cases. The median age was 7 years with 56,6% boys, less than 5% were classified as severe and less than 1% as critical.. The Korean Center for Disease Control and Prevention reported on 20 March that 6.3% of all COVID-19 cases were children under 19 years of age; again, the children had a mild form of the disease (Korean Center for Disease Control and Prevention. Press releases, https://www.cdc.go.kr). Italian data published on 18 March showed that only 1,2% of the 22,512 Italian cases with COVID-19 were children; no deaths were reported in this and in the Spanish cohort from Madrid (2 March to 16 March) (Livingstone 2020, Tagarro 2020). In Germany, 9657 children and adolescents with COVID-19 were reported up to May