Flu season has hit Alberta a bit later than usual this year.
In the past five years, lab-confirmed influenza cases saw notable increases starting in October, a trend that’s only seen a month or two variance going back to 2009.
This year, that increase started in March, a shift of six months.
Dr. Craig Jenne, an associate professor in the University of Calgary’s department of microbiology, immunology and infectious diseases, said the uptick in influenza in Alberta shouldn’t come as a surprise given all the factors.
“We saw this fall that, for example, vaccination rates for seasonal influenza shots were lower than normal in the province, so that means we had reduced protection,” Jenne told Global News.
So far this flu season, only 27.3 per cent of Albertans have received influenza shots. That’s down from 37.4 per cent the year before.
“As we move through spring, we have seen most public health guidance begin to ease. So people are now gathering and many of those measures that have protected us for the last two years, wearing masks, limiting indoor gatherings – they’re gone.”
Provincial data showed unabated growth in lab-confirmed seasonal influenza following the start of Step 2, when public health measures like gathering limits and indoor mask mandates expired.
“Just like COVID, influenza is a respiratory virus, and it will absolutely take advantage of those settings to spread between people.”
So far this flu season, 707 Albertans have had lab-confirmed influenza. The most recent reporting period ending April 17, showed 247 people testing positive for Influenza A. A month prior, that number was just 53.
Jenne said those numbers only represent a fraction of the actual cases in the community as influenza is not tested for very widely – usually only for those who could see severe outcomes of influenza.
Broken down by age group, those aged 90+ have had the highest rate of lab-confirmed influenza. Under one year old comes in second, followed by 80 to 89 years old, then one to four and five to nine-year-olds.
ICU admissions have only been among those aged 50 to 79 years old.
An AHS spokesperson said increases in influenza cases are a reminder “that you can be contagious with influenza before you even feel sick.”
But stopped short of explaining the sudden increase in documented cases.
“We cannot say for certain why we are seeing a sudden increase in cases.”
In the 2021-2022 influenza season, Alberta hasn’t yet seen a death due to the disease. But Jenne said in the years before COVID-19, influenza was the leading cause of death from infectious disease in North America, including Alberta.
As for COVID-19, immunization and measures to prevent airborne virus spread are the best ways to prevent severe outcomes from influenza. But the ongoing pandemic has worn on people.
“People are exhausted, people are tired of it, and it’s understandable. But unfortunately, these viruses really don’t care,” Jenne said, noting the methods to protect the most vulnerable members of a population are well-known.
“Wearing masks when you can’t physically separate. Limiting indoor gatherings in communities or at times of the year when there is an active virus are really protective.
“And the hope is – and past experience tells us – that as the weather now begins to warm and we do transition to going outside a lot more, we should see those flu numbers start to come down in the coming weeks.”