Acute respiratory infection emergency access in a tertiary care children hospital in Italy, prior and after the SARS-CoV-2 emergence.

Background: The COVID-19 pandemic has changed the epidemiology of acute respiratory infections (ARIs) in children. The aims of the present study were to describe the epidemiological trend of ARI emergency visits and virology results prior and after the SARS-CoV-2 emergence and to estimate the association of ARI emergency department (ED) visits with respiratory viruses.

Methods: This study was conducted at the Bambino Gesù Children's Hospital, a tertiary care children's hospital in the Lazio Region, Italy. The demographic and clinical information of children who accessed the ED and were diagnosed with ARI from January 1, 2018 to June 30, 2022 was retrospectively extracted from the electronic health records. The observed temporal trends in viruses diagnosed from respiratory samples were compared with the number of ARI ED visits over the same period through a multivariable linear regression model.

Results: During the study period, there were 72,959 ED admissions for ARIs and 33,355 respiratory samples resulted positive for viruses. Prior to the pandemic, respiratory syncytial virus (RSV) and influenza had a clear seasonal pattern, which was interrupted in 2020. In 2021-2022, RSV reached the highest peak observed during the study period, whereas influenza activity was minimal. The peaks of ARI ED visits corresponded to peaks of influenza, RSV, and rhinovirus in the 2018-2019 and 2019-2020 seasons, to SARS-CoV-2 and rhinovirus in 2020, and to RSV and parainfluenza in 2021-2022.

Conclusions: ARI resulting in ED visits should be included in the ARI disease burden measurement for a more accurate measure of the impact of preventive measures.