Cross-sectional case-control studies (Blue)
In mid-March 2020, many countries decided to close schools in an attempt to limit the spread of SARS-CoV-2, the virus causing Covid-19. Sweden was one of the few countries that decided to keep preschools (generally caring for children 1 to 6 years of age) and schools (with children 7 to 16 years of age) open. In this article, the authors present data from Sweden on COVID-19 among children 1 to 16 years of age and their teachers. In Sweden, COVID-19 was prevalent in the community during the spring of 2020. Social distancing was encouraged in Sweden,but wearing face masks was not. Data on severe COVID-19, as defined by intensive care unit (ICU) admission, were prospectively recorded in the nationwide Swedish intensive care registry. The authors followed all children who were admitted to an ICU between March 1 and June 30, 2020 (school ended around June 10) with laboratory-verified or clinically verified Covid-19, including patients who were admitted for multisystem inflammatory syndrome in children (MIS-C, which is likely to be related to COVID-19). The number of deaths from any cause among the 1,951,905 children in Sweden (as of December 31, 2019) who were 1 to 16 years of age was 65 during the pre–COVID-19 period of November 2019 through February 2020 and 69 during 4 months of exposure to COVID-19 (March through June 2020). From March through June 2020, a total of 15 children with COVID-19 (including those with MIS-C) were admitted to an ICU (0.77 per 100,000 children in this age group). No child with COVID-19 died. Data from the Public Health Agency of Sweden showed that fewer than 10 preschool teachers and 20 schoolteachers in Sweden received intensive care for COVID-19 up until June 30, 2020 (20 per 103,596 schoolteachers, which is equal to 19 per 100,000). As compared with other occupations (excluding health care workers), this corresponded to sex- and age-adjusted relative risks of 1.10 (95% confidence interval [CI], 0.49 to 2.49) among preschool teachers and 0.43 (95% CI, 0.28 to 0.68) among schoolteachers.
The authors concluded that even if the presence of some limitations, their study shows that, despite Sweden’s having kept schools and preschools open, a low incidence of severe COVID-19 among schoolchildren and children of preschool age during the SARS-CoV-2 pandemic was found. Among the 1.95 million children who were 1 to 16 years of age, 15 children had COVID-19, MIS-C, or both conditions and were admitted to an ICU, which is equal to 1 child in 130,000.