This year’s flu season has begun earlier than usual, according to the Public Health Agency of Canada.
The agency’s weekly FluWatch report found that there were 3,176 cases reported across Canada this season so far up to November 24, the most recent data available. Nine deaths were reported.
Flu cases are ramping up about a month earlier than average, said Dr. Gerald Evans, chair of the division of infectious diseases and a professor of medicine at Queen’s University.
He’s not sure why, saying it could be due to pure chance — somebody importing it from the southern hemisphere.
“The only thing I can tell you that’s a little worrisome is that, as you know, kids are still in school for another two weeks,” he said. “Schools bring kids together. Kids are very good virus factories — when they get infected, they make a lot of virus and they shed a lot of it. So if you get influenza into the community while schools are still in attendance, you tend to amplify it.”
That could mean a “takeoff” over the next few weeks, he said, in which case flu might peak over the holiday season. “As a health care worker it’s kind of your worst-case scenario,” he said, since a lot of staff might be on holiday.
WATCH: It has hit hard and hit early. An emergency room doctor is warning Calgary could have many more hospitalizations than usual this flu season.
So far, kids are also being hit hardest by the flu, according to public health data.
“The number of pediatric hospitalizations is significantly higher than in recent years,” reads a recent FluWatch report. “The number of influenza outbreaks remains within expected levels. However, the settings in which outbreaks have been reported this season suggests that younger age-groups are being affected more than in previous seasons.”
Dr. Isaac Bogoch, an infectious diseases specialist at the Toronto General Hospital, warns it’s a bit too early to say for sure whether this year’s flu strain is actually harder on children, or whether the higher numbers this year of hospitalized children are just a coincidence, and the trend won’t continue.
“It’s so early in the flu season that I think it’s very challenging to draw meaningful conclusions from the data that we have so far.”
“It’s very difficult to know how this will pan out at the end of the year.”
It’s also too early, said Evans, to tell how well the flu shot is working this year. “You need data to determine that.”
The Public Health Agency of Canada simply doesn’t have information on whether people who caught the flu had been vaccinated or not, said a spokesperson.
Instead, Evans said, researchers have to take samples of the virus and analyze them to see how well they match to strains that were in this year’s vaccine. This process can take weeks, and good results aren’t usually available until January.
WATCH: Staying healthy during the cold & flu season
Very early tests published in the most recent FluWatch report found that most of the roughly 100 viruses they found were strains present in this year’s vaccine.
“Right now, from what we can see, it looks like a very good match,” Evans said. Researchers were predicting, based on the southern hemisphere’s flu season, that the flu shot would be a better match than last year’s.
Even in a good year, though, the vaccine doesn’t confer complete immunity.
“If you’re looking at healthy people who get the flu shot in a good matched year, you’re looking at vaccine efficacy that should be around 70 per cent,” he said. However, that’s still better than zero.
Canadians aren’t very good about getting their flu shot, though. In the 2016-17 flu season, only about 36 per cent of adults got vaccinated, according to a national survey.
Even though flu season started early, you should still get vaccinated if you haven’t yet, Bogoch said.
“It’s the beginning of December and there is still a long season ahead of us. If you haven’t gotten the vaccine, absolutely go and get it.”
Evans agrees. “I think people should be really jumping on it now. To get the full immunogenic effect it takes about two weeks from your shot, but if it’s about to peak in two or three weeks, it’s the perfect time to get it.”