Summary

• During week 52 (December 25–31), all-cause activity increased by 23% among children under 2 years of age (+7,633 visits), by 7.7% among adults aged 15–74 (+17,248 visits), and by 14.7% among those aged 75 and older (+7,792 visits). Activity decreased among those aged 2–14. Hospitalizations also increased across all age groups (+15% (i.e., +827 hospitalizations) among children under 15 and +10% (i.e., +5,903 hospitalizations) among adults).

• Nearly all seasonal illnesses have increased over the past week, both among children (primarily under 2 years of age) and among adults. Of particular note are: - the increase in visits for influenza/flu-like illness among children (+56%, or +1,987 visits) and among adults (+107.5%, or +2,977 visits). These visits account for 2.6% of emergency department activity among adults and 7% among children, a higher proportion than that observed last year during the same period among children and adults aged 15–74, - an increase in visits for acute bronchitis (+24% among children and +62.3% among adults) and pneumonia (+17.4% among children and +52.4% among adults), at levels comparable to those of the previous year, - an increase in visits for isolated fever and ENT conditions across all age groups (respectively +20% and +23.6% across all ages), with a share of total activity higher than that of the previous year during this period, - an increase in visits among adults for gastroenteritis (+76%) and, to a lesser extent, for asthma (+36%).

• Among the most common conditions, excluding seasonal illnesses, there was an increase in visits among adults over 75 for cardiac decompensation (+24.6%) and dyspnea/respiratory failure (+21.6%).