Secondary transmission of COVID-19 in preschool and school settings in northern Italy after their reopening in September 2020: a population-based study

摘要

We report epidemiological investigations of transmission of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in 41 classes of 36 schools in Reggio Emilia province, northern Italy, from their reopening on 1 September to 15 October 2020. The overall secondary case attack rate was 3.2, reaching 6.6 in middle and high schools. More timely isolation and testing of classmates could be effective in reducing virus transmission in this setting.