Bronchiolitis epidemics in France during the SARS-CoV-2 pandemic: The 2020-2021 and 2021-2022 seasons

Abstract

Objectives: We described bronchiolitis epidemics during the 2020-2021 and 2021-2022 seasons in France and their interaction with the COVID outbreak.

Patients and methods: Data on family physician (FP) visits, emergency department (ED) visits, hospitalizations for bronchiolitis for children˂2 years, and hospital virological data were analyzed and compared with previous seasons (2015-2020).

Results: The 2020-2021 epidemic arrived very late, and its impact was lower than in previous seasons (2015-2020) (FP visits: -23%, ED visits: -38%, and hospitalizations: -30%). The 2021-2022 epidemic started early (week 40) and lasted for a relatively long time (13 weeks). The impact was higher than in 2015-2020 (FP visits: +13%, ED visits: +34%, hospitalizations: +28%).

Conclusion: Findings from the 2020-2021 epidemic may be linked to the implementation of non-pharmaceutical COVID-19 prevention measures. For 2021-2022, findings may be linked to an "immunity debt" resulting from the lower impact of the previous season.

Keywords: Bronchiolitis; COVID-19; Epidemic; France; RSV.