A man walks pass a sign for flu shots in Toronto. (Doug Ives/The Canadian Press)

Flu cases spike across Canada, signaling peak of epidemic: experts

The dominant influenza A strain is H3N2, which tends to infect seniors in greater numbers

The number of flu cases is continuing to rise across Canada, suggesting the peak of infections with one of the dominant circulating strains could come within a few weeks — or even sooner, say infectious diseases experts, who describe this influenza season as “unusual.”

“We really haven’t seen a season quite like this in a little while,” said Dr. Michelle Murti of Public Health Ontario, referring to the mix of two primary strains making people sick during this year’s epidemic.

The dominant influenza A strain is H3N2, a nasty virus that tends to infect the elderly in greater numbers, with concurrent circulation of a B strain, a type that typically causes less severe illness. Influenza B can also affect older people and is the strain that most often infects children.

READ MORE: Researchers claim the ‘man flu’ does exist

READ MORE: B.C. rolls out 2017 flu shots

“Normally in a season, we’ll see a peak of influenza A happening some time towards the end of December or through January,” Murti said Monday. “And as that is coming down toward the end of February, that’s when we start to see that peak of influenza B activity into the spring and later season.”

But this year’s B strain, known as B/Yamagata, began circulating in the fall, much earlier than is usually the case.

B.C., for example, is seeing an atypical 50-50 mix of H3N2 and B/Yamagata, although other regions in Canada may have different ratios of the two strains affecting their populations, Dr. Danuta Skowronski of the BC Centre for Disease Control said from Vancouver.

“The spike in influenza activity that we’re experiencing now is not unusual,” she said. “In fact, such a sharp increase in activity is a signature feature of influenza that distinguishes it from other respiratory viruses that have a more prolonged, grumbling activity through the winter period.”

Skowronski described graphs illustrating flu activity as looking like a church steeple — with a sudden rise, a peak and then a sharp decline.

“We are currently spiking, but whether we have passed the peak or are continuing to rise, it’s still too early to tell,” she said, adding that peaks may arrive at varying times across the country as regions and communities experience major upticks in cases at different points in the epidemic.

In its weekly FluWatch report, the Public Health Agency of Canada says there were 11,277 laboratory-confirmed cases of flu across the country as of Dec. 30 — about 70 per cent attributed to H3N2 — with more than 1,000 influenza-related hospitalizations and 34 deaths.

However, Murti said those figures are an underestimate of the actual number of cases, as most people don’t seek medical attention for flu and, therefore, aren’t tested. As well, not all provinces and territories keep track of hospitalizations due to influenza.

“Looking at our numbers over the last couple of weeks and knowing there’s a bit of a reporting delay, we’re certainly on the upswing right now in terms of increasing activity for flu,” she said of Ontario. “So probably in the next few weeks, we’re going to continue to see increased activity.”

Murti predicts the province’s peak — for H3N2 cases, at least — will likely come in the next few weeks.

“But you really don’t know the peak until you’re coming down the other side,” she said.

Sheryl Ubelacker, The Canadian Press

Just Posted

Eckville students brave the cold to participate in annual Terry Fox Run

Roughly 250 students ran the three kilometre course in support of cancer research.

128 Flags of Remembrance now flying in Sylvan Lake until Nov. 12

Centennial Park boasts 128 Canadian flags to honour 128,000 Canadians killed and missing in action.

New Habitat for Humanity project coming to Sylvan Lake

Habitat for Humanity Red Deer is spreading the word about the new build in Sylvan Lake

Local filmmaker works on documentary featuring women farmers

Red Deer woman receives $50,000 grant from STORYHIVE to produce documentary

Sylvan Lake and Eckville under snow fall warning

Environment Canada issued the warning Saturday morning.

Video: Flyers new mascot ‘Gritty’ a bearded, googly-eyed terror

The Philadelphia Flyers unveiled their new mascot Monday, and as one would expect of the team that gave us the “Broad Street Bullies,” he’s far from cuddly.

Edmonton cannabis company revenues more than triples to $19.1 million

Aurora Cannabis revenues more than triple in fourth quarter

Seattle one step closer to NHL after arena plan approved

Seattle City Council unanimously approved plans for a privately funded $700 million renovation of KeyArena

Hockey league gets $1.4M for assistance program after Humboldt Broncos crash

Program will help players, families, coaches and volunteers after the shock of the deadly crash

Canada has removed six out of 900 asylum seekers already facing U.S. deportation

Ottawa had said the ‘overwhelming majority’ had been removed

Appeal pipeline decision but consult Indigenous communities, Scheer says

The federal appeals court halted the Trans Mountain expansion last month

‘I’ll never forgive you:’ Victim impact statements at hearing for Calgary killer

Curtis Healy was found guilty of first-degree murder Friday in the death of Dawns Baptiste.

Man accused of mailing bomb to his brother in B.C. has died

Leon Nepper was found in ‘medical distress’ at the Whitehorse Correctional Centre on Sunday

Most Read