Canada's annual flu season is back.
"At the national level, influenza activity has crossed the seasonal threshold, indicating the start of an influenza epidemic," the Public Health Agency of Canada (PHAC) said in its weekly FluWatch report, posted on Monday.
"All surveillance indicators are increasing and most are above expected levels typical of this time of year."
Indicators include people self-reporting cough and fever at levels beyond typical for this time of year and visits to doctors for flu-like symptoms.
Localized flu activity was reported in regions of New Brunswick, Ontario, Saskatchewan and Alberta. It was spreading less commonly in regions of Newfoundland and Labrador, P.E.I., Nova Scotia, New Brunswick, Quebec, Ontario, Saskatchewan and Alberta, the report said.
This year's flu season also started "more than a month earlier than typically observed in pre-pandemic seasons."
During the height of the COVID-19 pandemic, flu did not circulate in Canada.
Influenza was also at historic lows in both the Northern and Southern hemispheres last year as public health measures like staying home when sick, masking, physical distancing and lockdowns were in place to stop the spread of COVID-19, according to PHAC's annual influenza report.
Overall, respiratory syncytial virus (RSV) activity is increasing and also exceeds expected levels for this time of year, the agency's Respiratory Virus Report said for the week ending Nov. 5.
WATCH | Flu cases on the rise across Canada: