Influence of the COVID-19 pandemic on the epidemiology of acute bronchiolitis

INTRODUCTION: The COVID-19 pandemic has changed the circulation of some viruses associated with acute bronchiolitis. We analyzed the epidemiology of bronchiolitis admissions during the COVID-19 pandemic compared with 8 previous epidemic seasons. METHODS: An observational and ambispective study was performed, including infants admitted with bronchiolitis in a tertiary hospital during 2 periods: COVID-19 pandemic (15th March 2020 to 3rd August 2021) and pre-pandemic (1st September 2012 to 14th March 2020). Demographic, clinical data and etiologies were collected. RESULTS: Five hundred ten patients were hospitalized with bronchiolitis: 486 in the pre pandemic period with an average of 61 admissions per season vs 24 during the pandemic, observing a 60.7% reduction in bronchiolitis admissions. During the pandemic, bronchiolitis outbreak was delayed until spring-summer 2021. Respiratory syncytial virus was the most frequent etiological agent in both periods. CONCLUSION: We observed a change in the seasonality of bronchiolitis during the pandemic COVID-19, possibly influenced by control measures against SARS-CoV-2.