What's behind Alberta's spike in flu numbers

If you thought May was too late for flu season, think again. 

Alberta Health Services data shows influenza cases have spiked across the province in recent weeks, with more than 200 cases being recorded in Calgary alone.

And those numbers may just be the tip of the iceberg according to Dr. Eddy Lang, clinical department head for emergency medicine for the Calgary zone with AHS.

"There are many, many more people out there who probably do have the flu," Lang told CBC Calgary News at 6.

"They just haven't tested for it."

Lang said health professionals carrying out COVID tests have been surprised to see results come back positive for influenza, given the prevalence of the COVID virus now in the province. 

He said it's unusual to see so many influenza cases at this time of year, but not necessarily surprising, now that travel has picked up and people are in closer contact with each other. 

"It's almost incredible that the last two winters have gone essentially without a flu season." 

Craig Jenne, an associate professor of microbiology, immunology and infectious diseases at the University of Calgary, said another potential cause of the recent spike in flu numbers is that not as many people were vaccinated against the virus this season. 

"We do have to keep in mind that at least early in the flu season … vaccines were well below our normal rate of vaccination in Alberta," said Jenne.

"So if we have a lower level of protection, it's perhaps not surprising that the flu season is stretching itself out a little longer than usual."

Jenne said that in the midst of needing multiple COVID-19 vaccine boosters, people are likely feeling the effects of vaccination fatigue.

"I think what we're seeing is really the effect of a couple of years of little to no flu that we perhaps let our guard down a little bit."

Lang said that while this year's bug doesn't seem particularly hard to beat, it's still something people should be aware of, especially as the infection will produce some similar symptoms as COVID. Jenne said it's important for Albertans to know that the flu is still a serious concern for some people. 

"Prior to the pandemic, influenza or the flu was actually the leading cause of death in Canada from any infectious disease," said Jenne. 

"It's something we've gotten used to. But it underscores that it does still have the potential to cause serious health impacts." 

Both Jenne and Lang said that they expect influenza numbers to decrease in the coming weeks as people start spending more time outdoors.