Key Points

The 2022–2023 bronchiolitis epidemic in mainland France began in week 40 of 2022 (October 3–9, 2022). The peak was reached in week 48 of 2022 (November 28–December 4, 2022), and the outbreak ended in week 3 of 2023 (January 16–22, 2023). As in the previous season, the epidemic began early (6 weeks earlier than the average observed over the 2015–2020 period) and lasted longer (16 weeks vs. 12 weeks on average over the 2015–2020 period). This outbreak was characterized by very high intensity, nearly twice the average values of reference outbreaks, particularly in terms of emergency department visits and hospitalizations following emergency department visits for bronchiolitis among children under 2 years of age. However, the proportion of hospitalizations for bronchiolitis among children under two years of age following emergency department visits remained comparable to that of seasons preceding the circulation of SARS-CoV-2 (2015–2020), indicating that the epidemic was not particularly severe.