Hospitalizations for bronchiolitis among infants before and after the SARS-CoV-2 pandemic: an area-based study of the Emilia-Romagna Region, Italy

BackgroundBronchiolitis is the most frequent lower respiratory tract infection and a leading cause of hospitalization in infants. Our aim was to assess the incidence and characteristics of bronchiolitis requiring hospital admission in an Italian region before and after the SARS-CoV-2 pandemic.MethodsThis area-based retrospective study analyses 4,396 hospital discharge records (HDR) of children under 1 year of age admitted with a diagnosis of bronchiolitis (ICD9-CM codes 466.11 and 466.19), in Emilia-Romagna (Italy) from January1st, 2018 to December 31th, 2021. Weighted t-testing and Z-testing was carried out.Resultsin the study period, 2-4% of infants were admitted for bronchiolitis (10% of all admissions under 1 year) and 59% of them were aged less than 90 days. After a significant decrease in 2020, bronchiolitis resurged in 2021, and Respiratory Syncytial Virus (RSV) cases reached 82%. RSV cases were more likely to undergo non-invasive ventilation (NIV), oxygen supplementation and to receive i.v. (intravenous) infusions. There was an overall increasing trend in NIV and oxygen supplementation, and a decreasing trend in chest X-rays.ConclusionsThis area-based study shows reduced hospital admissions due to bronchiolitis during the SARS-CoV-2 pandemic and a resurgence of RSV infection after the easing of preventive measures. We also provide information on length of stay and need for hospital treatments. These area-based information will be helpful in assessing the impact of future universal prevention measures.