Canada’s colder weather goes hand-in-hand with respiratory virus season, with flu, RSV and COVID-19 circulating. While Canadians learned a lot about how to protect themselves from illness during the height of the pandemic, new information released by health care practitioners can help inform decisions, including the availability of flu shots.
We’ll be publishing an update on respiratory virus season at the beginning of each week. Looking for more information on the topic that you don’t see here? Email audience@globeandmail.com to see if we can help you.
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The latest news
- Influenza activity is on the rise across Canada, according to the Public Health Agency of Canada’s updated respiratory virus surveillance report. Toronto and the Vancouver coastal region of British Columbia were hit particularly hard in the third week of January but increased influenza activity was seen across much of the country. Only Newfoundland and the Northwest Territories appeared unaffected.
- Apart from the more well-known suspects, there are other viruses making the rounds across Canada. Infectious disease specialist Zain Chagla said case counts of norovirus are higher than expected for this time of year. Norovirus, sometimes known as the “winter vomiting disease,” is a highly contagious gastrointestinal illness that causes diarrhea and – you guessed it – vomiting. More on that below.
Outlook on RSV, COVID and flu in Canada:
- The proportion of tests that came back positive for flu during the third week of January was 13.6 per cent, up from 11.8 per cent the week prior, according to PHAC data updated last Friday. Quebec and B.C. have the highest positivity rates at 15.4 and 15.3, respectively, followed by Ontario at 14.1 per cent.
- Positivity rates for COVID continue to decline across Canada, dipping to 6.8 per cent from 8.5 per cent, while RSV rates are stable. Ontario continues to have the highest positivity rate for COVID at 11 per cent; the national average is 6.8 per cent. Meanwhile, Atlantic Canada and the Prairie provinces have the highest RSV activity.
Why is norovirus circulating and what can I do to protect myself and my family?
Part of the problem with norovirus is that it can spread easily and quickly between people, including by sharing food and utensils with an infected person, eating contaminated food or drinks, touching contaminated surfaces or by caring for someone who is sick (including by cleaning vomit or changing diapers).
“The amount of virus that’s needed to actually trigger an infection for someone is minuscule,” explained Dr. Chagla. Studies have suggested that as little as 15 particles of the virus can cause infection; other viruses require thousands. To put that into perspective, vomit has “millions and million” of particles. Just a trace can make you ill.
COVID-19 vaccines: What to expect in the next few months
Symptoms can start as soon as 12 hours after exposure and usually last a handful of days. Stomach pain, cramps and nausea are other common symptoms but people also experience chills, fatigue, headaches, muscle aches and a mild fever. Infected people are most contagious while they have symptoms and at least three days after recovery but can transmit the virus for up to three weeks post-illness.
Dr. Chagla said an easy way to protect yourself is by washing your hands. But, he warned, hand sanitizer won’t do the trick as the virus is more resistant to its chemicals. Instead, stick to the basics: regularly lather soap into your hands for about two minutes, making sure to clean your palms, the back of your hands, between your fingers and under your nails.
And, Dr. Chagla stressed, stay home if you are feeling sick.
Hospitalizations for COVID, RSV and flu:
- There have been about 1,355 flu-related hospitalizations across Canada since last August, according to PHAC, including 141 hospitalizations during the third week of January. More than 100 cases have required admission into intensive care units, and 56 deaths have been recorded, so far this season.
- COVID infections have sent 4,035 people to hospital with nearly 300 cases requiring intensive care. Just shy of 800 people have died since August, primarily among individuals 65 and older. PHAC does not have any data on severe outcomes related to RSV for the 2024-25 season.
How to protect yourself and your loved ones from respiratory viruses:
- Respiratory viruses can spread from person-to-person or through contact with contaminated surfaces or objects, such as phones, door handles or elevator buttons. To protect yourself and others, Health Canada recommends wearing a well-fitted respirator or mask, getting vaccinated, washing your hands regularly, cleaning high-touch surfaces, improving indoor ventilation, and covering your mouth when sneezing or coughing. People are encouraged to stay home when sick.
Seasonal shots:
Flu and COVID shots are available across the country. It is safe to receive both vaccines at the same time. Immunization information for all provinces and territories can be found here:
- Alberta
- British Columbia
- Manitoba
- Newfoundland
- New Brunswick
- Northwest Territories
- Nova Scotia
- Nunavut
- Ontario
- Prince Edward Island
- Quebec
- Saskatchewan
- Yukon
What are your questions about this year's respiratory virus season?
Canada’s colder weather goes hand-in-hand with respiratory virus season – especially with flu, RSV and COVID-19 circulating. The Globe will be publishing an update on respiratory virus season at the beginning of each week, providing information on how Canadians can protect themselves from illness and new information released by health care practitioners.
Have a seasonal illness-related question for our reporters? Share it below, or email us at audience@globeandmail.com.