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

## TL;DR

The study found that hospitalizations for bronchiolitis in infants dropped during the SARS-CoV-2 pandemic but rose again in 2021, with RSV being a major cause.

## Contribution

The study provides area-based insights into bronchiolitis hospitalization trends and treatment needs before and after the SARS-CoV-2 pandemic.

## Key findings

- Hospital admissions for bronchiolitis decreased in 2020 but resurged in 2021 after pandemic restrictions eased.
- RSV accounted for 82% of bronchiolitis cases and was associated with higher use of non-invasive ventilation and oxygen.
- There was a decreasing trend in chest X-rays and increasing use of non-invasive treatments over the study period.

## Abstract

Bronchiolitis 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.

This 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.

in 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.

This 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.