COVID-19 Pandemic: Influence of Schools, Age Groups, and Virus Variants in Italy

The estimated smooth curve of the percentage of subjects positive to SARS-CoV-2 started decreasing in Italy at the beginning of January 2021, due to the government containment measures undertaken from Christmas until 7 January. Approximately two weeks after releasing the measures, the curve stopped to decrease and remained approximately constant for four weeks to increase again in the middle of February. This epidemic phase had a public health care impact since, from the beginning of the fourth week of February, the curve of the intensive care unit's occupancy started to grow. This wave of infection was characterized by the presence of new virus variants, with a higher than 80% dominance of the so-called English variant, since 15 April. School activities in Italy started at different times from 7 January until 8 February, depending on every region's decision. Our present data on the incidence of SARS-CoV-2 in different age groups in Italy are in agreement with literature reports showing that subjects older than 10 years are involved in virus transmission. More importantly, we provide evidence to support the hypothesis that also individuals of age 0-9 years can significantly contribute to the spread of SARS-CoV-2.

Automated summary

The estimated smooth curve of the percentage of subjects positive to SARS-CoV-2 in Italy started decreasing in early January 2021 due to government containment measures and new virus variants. The reopening of school activities and the involvement of different age groups in virus transmission also played a role.