This flu season has hit people harder than expected — and even though cases are dipping, experts warn the virus is still a threat.
Some Toronto hospitals have been operating at capacity, as children and seniors have been hit hard with flu complications. In one hospital, patients over 65 made up 72 per cent of influenza hospitalization admissions.
“We’re absolutely still in a very heavy influenza season,” said Dr. Michelle Murti, the medical officer of health at Toronto Public Health. “There’s still quite a lot of influenza coming ahead of us in the coming weeks.”
It all traces back to H3N2, a new mutated strain of Influenza A.
The strain tends to cause more severe infections than the H1N1 strain, another form of the Influenza A virus, and has been called a possible “mismatch” for this year’s flu vaccine, though doctors say it would still provide protection against the mutation.
The percentage of flu tests that were positive reached a high of 33.3 per cent for the week ending on Dec. 27, the highest number recorded in the past three seasons, according to the Public Health Agency of Canada’s latest numbers. In comparison, the peak last year was 27.6 per cent.
For the week ending on Jan. 3, there were 13,471 influenza detections, or 27.1 per cent, a decrease from the previous week, which sat at 33.3 per cent.
Since this current influenza wave reached such high numbers, Murti said it would take some time to come down. “We’ve only really come down to where we were last year.”
Here’s what you need to know about what the rest of the season will look like.
Are we expecting another influenza wave?
One thing to keep an eye on is the emergence of Influenza B virus, which can be a more severe infection for children. This “second wave” will likely last until late March or early April, Murti said.
Among national influenza detections, Influenza A accounted for 98.7 per cent of cases while Influenza B accounted for 1.3 per cent, according to the Public Health Agency of Canada.
Influenza A and Influenza B can lead to similar symptoms, such as fever, cough and body aches, though Influenza B is considered to be milder than Influenza A, which causes more severe illness.
There are “much fewer deaths and fewer associated hospitalizations” with Influenza B, said Dr. Alon Vaisman, an infection control and infectious disease physician at the University Health Network.
“Influenza B is less aggressive, less likely to cause morbidity, mortality than Influenza A,” he said.
What’s been happening inside hospitals this flu season?
Several hospitals are seeing all kinds of patients swarm their emergency departments, with severe respiratory symptoms. Many have implemented masking and handwashing protocols to protect both patients and staff, who are beginning to come down with illness.
Dr. Barry Pakes, a public health specialist physician and director of the Public Health and Preventive Medicine Residency Program at the University of Toronto, said he keeps seeing patients with “high fevers that last a long time and more respiratory distress than before.
“I was just overwhelmed by how incredibly sick people were compared to previous (seasons), even COVID.”
Throughout his 20-year career, Pakes said he’s never seen so many “really ill people,” and the strain placed on hospital staff and resources. The next four to six weeks will remain difficult for hospitals as they work through patients that were admitted throughout the holiday season with the flu.
What are the long-term effects of this strain?
While it’s still too early to understand the long-term effects of this strain, Pakes said virus infections usually cause lung scarring and breathing difficulties.
There have been “big pressures” on the health-care system, Murti said, because of this flu season, particularly for patients who need hospitalization.
“It’s not just an in-and-out with that infection that many people, especially for the elderly population, go to the hospital and they have to stay,” she said.
“Sometimes they get secondary infections, pneumonias, bacterial infections, that can be quite a life-changing experience.”
Is it too late to get my flu shot?
No, it’s not too late for you to get your flu shot.
While it’s recommended ahead of the flu season, Vaisman said there are still benefits to getting the vaccine. The shot contains several flu strains, aiming at providing broad protection against viruses that are most common in the coming flu season.
People looking to get the flu shot will still be protected from those strains and can “potentially gain immunity” from future strains.
“Vaccination is helpful regardless of where you are in the flu season.”
Many major pharmacies, including Shoppers Drug Mart and Rexall, offer flu shots, as do primary care providers, community clinics and travel health clinics. Flu shots are free for those six months and up, who live in Ontario.
What can you do to protect yourself and loved ones?
Despite the start of the flu’s decline, Murti said there is an ongoing risk for vulnerable populations, which includes children under five and people over 65.
Getting the flu vaccine remains the most effective prevention measure. Other measures include practising proper hand hygiene, masking, improving indoor air quality and staying home while sick.
“Whatever we can do to try to keep (the spread) coming down as quickly as we can is really helpful,” she said.
Vaisman hopes the discussion around this year’s flu season can extend into higher vaccination rates. He notes that influenza coverage in the 2023-24 flu season only reached 42 per cent, according to the Public Health Agency of Canada.
“This season reminds us how important it is, how deadly the flu is, how important it is to get influenza vaccination.”
