Paediatric acute bronchiolitis is typically seasonal, occurring from October to April in the northern hemisphere, but COVID-19 preventive measures led to a decrease in cases during the 2020-21 season.
A study involving 6,334 infants in Spain examined the epidemiological changes in acute bronchiolitis cases before, during, and after COVID-19 interventions from September 2021 to August 2023.
The findings revealed unexpected out-of-season peaks in bronchiolitis cases in the summers of 2021 and 2022, along with significant increases in hospitalization metrics in 2022-2023 compared to prior seasons.