Epidemiological shifts in bronchiolitis patterns and impact of the COVID-19: A two-season comparative study

Abstract

Background: Bronchiolitis is a common lower respiratory tract infection (LRTI) affecting infants and young children. Respiratory syncytial virus (RSV) has historically been the primary causative agent, but other viruses also contribute to the LRTI epidemiology. Recent changes in epidemiology and clinical patterns due to the coronavirus disease 2019 (COVID-19) pandemic have raised concerns. This study aims to analyze the impact of the pandemic on bronchiolitis epidemiology and severity. Methods: Two consecutive bronchiolitis seasons (October 2021 to March 2022 and October 2022 to March 2023) were compared. Data on viral agents, hospitalization duration, clinical severity, and respiratory support requirements were collected from pediatric patients at San Marco Hospital, University of Catania. Results: In the 2021–2022 season, RSV was the predominant virus (40%), followed by other viruses, with mild clinical outcomes. In the 2022–2023 season, RSV remained prevalent (58.7%), but other viruses, including rhinovirus (RV) and influenza, showed a significant increase (p