If you’re bundled up in blankets, battling a fever and feeling the aches set in, you’re not alone. Influenza A, better known as the flu, is on the rise.
Influenza cases have been on the rise in recent weeks, according to the Public Health Agency of Canada (PHAC). As of Feb. 1, 21.2 per cent of tests have come back positive for influenza, up from 16.91 per cent the previous week.
In Canada, flu season typically runs from November to April, and while anyone can catch the flu, the virus can sometimes lead to severe complications — even death, which is why experts stress the importance of the annual flu shot.
Compared to this time last year, PHAC data shows that flu cases are spiking much later than in previous seasons. During the 2022 to 2023 season, cases peaked at the end of November, while last year, the peak came at the end of December.
This flu season also appears to be returning to a more “pre-COVID” pattern, with cases rising in late January and early February, explained Christopher Labos, a Montreal-based cardiologist and epidemiologist.
“The flu is always a little bit different every year because it’s a different virus,” he told Global News. “But during COVID there was a lot of disruption to the normal circulatory patterns of viruses, like RSV during the summer and starting earlier and ending earlier. So there was a little bit of variability in 2021, 2022 and 2023.”
Because COVID-19 disrupted many viruses, it may explain why recent flu seasons peaked much earlier or later than usual. Labos believes this current season is more in line with pre-COVID flu patterns, where peaks typically occur in January.
It’s unclear when cases will decline, Labos added, but predicted a plateau in the next few weeks as warmer weather helps bring flu season to an end.
Flu is a contagious respiratory illness that infects the nose, throat and sometimes the lungs, according to the United States Centers for Disease Control and Prevention (CDC).
There are two main types that cause seasonal flu in humans: influenza A and influenza B. Influenza A is more common and can cause more severe outbreaks, while influenza B tends to be milder but still contributes to flu season.
Currently, in Canada, PHAC data shows influenza A is dominating, accounting for 94.2 per cent of all cases in Canada.
The flu spreads through respiratory droplets when an infected person coughs, sneezes or talks. These droplets can land in the mouths or noses of people who are nearby. It can also spread by touching contaminated surfaces and then touching the face.
It can be hard to tell the difference between symptoms of the flu and other respiratory illnesses like COVID-19, Labos said.
“There is a lot of overlap between the symptoms. You can maybe take a guess if you have very widespread myalgia — sore muscle pain consistent with influenza,” he explained. “If you’re having a very, very sore throat, that might be more consistent with COVID. But there is no reliable way to know. You have to test.”
Flu symptoms may vary from person to person, according to Health Canada. Symptoms usually appear one to four days after exposure to the virus and include:
- fever
- cough
- muscle aches and pain
- chills
- tiredness
- headache
- sore throat
- loss of appetite
- runny or stuffy nose
Children may also suffer from diarrhea, nausea and vomiting.
The most commonly-reported symptoms this flu season include cough and fever, according to PHAC.
Who is most at risk of the flu?
The elderly, immunocompromised individuals and those with preexisting health conditions are most at risk for severe cases and hospitalization.
PHAC data shows a majority of flu outbreaks in Canada (65.1 per cent) have been reported in long-term care facilities. Others include retirement homes and acute care.
However, while young, healthy individuals can usually recover from the flu at home, Labos emphasized many people underestimate how severe influenza can be.
“If you’re young and healthy, you probably will survive influenza and you might be able to ride out the symptoms at home,” he said. “But you are going to feel the muscle aches, and they can be incapacitating. So even young, healthy people can have fairly severe symptomatology.’
He added that influenza can be a very serious virus, claiming thousands of lives each year.
Although flu cases are up, PHAC said the rate of weekly hospitalizations linked with the virus has been generally stable in recent weeks.
Since Aug. 25, 2024, a total of 76 influenza-associated deaths were reported in Canada.
Flu symptoms can often be managed at home with plenty of rest, staying hydrated with fluids like water, and using over-the-counter medication to reduce fever and body aches, PHAC said. Most people recover from the flu in seven to 10 days.
In some cases, a health care provider may prescribe antiviral medication, especially if you have severe symptoms or are at higher risk for complications.
Over-the-counter cough and flu medicine should not be given to children under six unless specifically advised by a healthcare provider.
You should go to the emergency room if flu symptoms become severe, PHAC added. In adults, warning signs include difficulty breathing, chest pain, confusion, persistent dizziness, severe dehydration or a high fever that won’t go down.
For children, watch for fast or troubled breathing, bluish skin or lips, extreme drowsiness, irritability, fever with a rash or signs of dehydration like dry mouth and no urination for several hours.
Babies under three months should be seen if they have any fever, trouble feeding, difficulty breathing or unusual sleepiness.
The first line of defence against influenza is the flu shot, Labos said. With cases on the rise, he suggests that anyone who hasn’t been vaccinated should still get the shot, as it’s not too late.
“If you’re going to be in a high-risk situation or public transport, like a plane, if you’re going to be in a place where you’re breathing the same air with a bunch of different people and you’re at high risk, I would wear a mask,” he added.
And of course, washing your hands frequently with soap and water is one of the best ways to prevent the spread of germs.
