Key points

Bronchiolitis

• An early outbreak, beginning in mid-September and unusually long (lasting 14 weeks).

• An intense outbreak, similar to the 2018–2019 season, with a peak in activity in early November in primary care and in late November in emergency departments.

• An outbreak characterized by low RSV circulation at the start of the outbreak and, overall, lower than in previous seasons.

Influenza

• An early epidemic, beginning in mid-November and lasting a long time (23 weeks).

• A double epidemic wave due to the successive circulation of two different influenza viruses: predominantly type A H3N2 during the first wave and type B during the second.

• The first wave was very intense and severe in terms of hospitalizations and mortality.

• The second wave was less severe but longer, particularly in community practice.

COVID-19

• Three successive waves of decreasing intensity.

• Exclusive circulation of the Omicron variant and its subvariants.

• More frequent infections and severe cases among people over 75 years of age.

Acute gastroenteritis

• Emergency department activity remained at baseline levels.

• An increase in activity in primary care beginning in early 2023, with an epidemic peak in early February.