Evolution of SARS-CoV-2 epidemics in pediatric population in Liguria (North-west Italy) from March 2020 to December 2022: what could we have learned?

Introduction: This retrospective analysis aims to follow the course of SARS-CoV-2 infections in pediatric population residing in Liguria, North-west Italy, from March 2020 to December 2022 and to relate it to the regional and national containment measures adopted, to assess the representativeness of the infection rate observed at the national level and to analyze the vaccination rates in different pediatric groups.

Methods: First episodes of SARS-CoV-2 infections registered in the national surveillance system were extracted and further anonymously analyzed for subjects aging ≤ 19 years. The absolute number of cases diagnosed daily during each year was compared to the number of residents in the region and graphical representations were used to visualize the trends in infection rates both annually and weekly in each year. Through narrative analysis, the relationship between changes in IR and key social events was analyzed.Applying the direct standardization method, the epidemiology of SARS-CoV-2 infection in pediatric population was compared with that observed in the same age group in Italy.All analyses were performed using Stata and Microsoft Excel.

Results: In the study period, 106,537 (17.4%) cases of SARS-CoV-2 infection were registered in subjects ≤ 19 years, out of a total of 610,404 cases reported in Liguria during that period. In the summer of 2020 the IR was close to zero, while later we observed increases and decreases in the IR in relation to activities and social restrictions adopted. Direct standardization showed an almost perfect coincidence between the expected cases in Italy, based on the Liguria incidence, and the observed cases.

Conclusions: Our results show that, in absence of effective therapies and vaccines, strict non-medical interventions (e.g. use of masks, improving indoor ventilation, physical social distancing, general lockdown) can be the only actions to counter the spread of a respiratory infection.