COVID-19 and schools: what is the risk of contagion? The results of an antigen rapid test-based screening campaign in Florence (Italy).

INTRODUCTION: in the COVID-19 era, the debate around the risk of contagion at school, is intense in Italy. The Department of Welfare and Wealth of Florence promoted a screening campaign with antigen rapid tests for all the students and school personnel. The aim of this study is to assess the SARS-Cov2 circulation in the school setting by means of a mass screening conducted in every primary and middle school of Florence. METHODS: All the students attending primary and middle schools of Florence and the school personnel were asked to take part. The campaign started on 16th November 2020 and was completed on 12th February 2021. If the antigen rapid test resulted positive, a molecular test was provided to confirm the result. RESULTS: 18,414 subjects were tested with 15,233 students (82.7%) and 3,181 members of the school personnel (17.3%). Only in 27 cases (0.15%) the rapid test gave a positive result. Moreover, only 14 of the 27 positive rapid tests were confirmed as positive by the molecular test. These results show a very low number of SARS-CoV-2 cases among the people tested (0.08% of the total). CONCLUSIONS: These results show that the spread of SARS-CoV-2 infection at school, during the months of the screening and with the respect of strict preventive measures was low.