Summary

• During week 51 (December 18–24, 2017), all-cause activity increased slightly among children (+5%, or +4,871 visits) and remained stable among adults. Hospitalizations remained stable across all age groups.

• Among seasonal illnesses, the following stand out in particular: - an increase in visits for influenza/flu-like illness among children (+97%, or +1,682 visits) and among adults (+89%, or +1,260 visits). These visits account for 1% of emergency department activity among adults and 3% among children (2% last week). The share of activity among children is now higher than that observed last year for the same period. Related hospitalizations are stable except among those aged 75 and older, with 64% of hospitalizations in week 51 compared to 58% in week 50, - an increase in visits for ENT conditions (+23% among 2-14-year-olds and +28% among adults), acute bronchitis (+19% among 2- to 14-year-olds and +31% among adults), pneumonia (+10%) among adults over 15 years of age, and isolated fever (+18%) across all age groups.

• Among the most common conditions, aside from seasonal illnesses, the only notable trend is a slight increase in visits for urinary tract infections (+5%) among adults over 15 years of age.