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

Larosa, Elisabetta; Djuric, Olivera; Cassinadri, Mariateresa; Cilloni, Silvia; Bisaccia, Eufemia; Vicentini, Massimo; Venturelli, Francesco; Giorgi Rossi, Paolo; Pezzotti, Patrizio; Bedeschi, Emanuela; Costantini, Massimo; Giorgi Rossi, Paolo; Grilli, Roberto; Marino, Massimiliano; Formisano, Debora; Formoso, Giulio; Bedeschi, Emanuela; Perilli, Cinzia; Venturi, Ivano; Bisaccia, Eufemia; Larosa, Elisabetta; Cassinadri, Mariateresa; Cilloni, Silvia; Campari, Cinzia; Gioia, Francesco; Broccoli, Serena; Ottone, Marta; Pattacini, Pierpaolo; Besutti, Giulia; Iotti, Valentina; Spaggiari, Lucia; Mancuso, Pamela; Nitrosi, Andrea; Foracchia, Marco; Colla, Rossana; Zerbini, Alessandro; Massari, Marco; Ferrari, Anna Maria; Pinotti, Mirco; Facciolongo, Nicola; Lattuada, Ivana; Trabucco, Laura; De Pietri, Stefano; Danelli, Giorgio Francesco; Albertazzi, Laura; Bellesia, Enrica; Canovi, Simone; Corradini, Mattia; Fasano, Tommaso; Magnani, Elena; Pilia, Annalisa; Polese, Alessandra; Incerti, Silvia Storchi; Zaldini, Piera; Bonelli, Efrem; Orsola, Bonanno; Revelli, Matteo; Salvarani, Carlo; Venturelli, Francesco

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.