Background School attendance during the COVID-19 pandemic is intensely debated. Aim In November 2020, we assessed SARS-CoV-2 infections and seroreactivity in 24 randomly selected school classes and connected households in Berlin, Germany. Methods We collected oro-nasopharyngeal swabs and blood samples, examining SARS-CoV-2 infection and IgG antibodies by RT-PCR and ELISA. Household members self-swabbed. We assessed individual and institutional prevention measures. Classes with SARS-CoV-2 infection and connected households were retested after 1 week. Results We examined 1,119 participants, including 177 primary and 175 secondary school students, 142 staff and 625 household members. SARS-CoV-2 infection occurred in eight classes, affecting each 1–2 individuals. Infection prevalence was 2.7% (95% confidence interval (CI): 1.2–5.0; 9/338), 1.4% (95% CI: 0.2–5.1; 2/140), and 2.3% (95% CI: 1.3–3.8; 14/611) among students, staff and household members. Six of nine infected students were asymptomatic at testing. We detected IgG antibodies in 2.0% (95%CI: 0.8–4.1; 7/347), 1.4% (95% CI: 0.2–5.0; 2/141) and 1.4% (95% CI: 0.6–2.7; 8/576). Prevalence increased with inconsistent facemask-use in school, walking to school, and case-contacts outside school. For three of nine households with infection(s), origin in school seemed possible. After 1 week, no school-related secondary infections appeared in affected classes; the attack rate in connected households was 1.1%. Conclusion School attendance under rigorously implemented preventive measures seems reasonable. Balancing risks and benefits of school closures need to consider possible spill-over infection into households. Deeper insight is required into the infection risks due to being a schoolchild vs attending school.
【저자키워드】 COVID-19, SARS-CoV-2, children, adolescents, Schools, Germany, 【초록키워드】 SARS-COV-2 infection, COVID-19 pandemic, Infection, risk, RT-PCR, ELISA, Prevalence, IgG antibody, Secondary infection, Measures, Asymptomatic, household, IgG antibodies, Germany, attack rate, Households, School, Swab, preventive measures, infection risk, Berlin, SARS-CoV-2 infections, secondary infections, Blood, with infection, preventive measure, secondary school, school attendance, Participants, 95% CI, 95% confidence interval, Blood samples, infection risks, balancing, infection prevalence, benefit, Randomly, Result, selected, affected, collected, occurred, examined, required, nine, eight, individuals, affecting, case-contact, 【제목키워드】 cross-sectional, Transmission,