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

New apartment building proposed in Tofino

Tim Hackett hopes to build a 32-unit, three-storey apartment building.

Tla-o-qui-aht First Nation demands transparency from leadership

“Right now there’s a lot of heartache.”

Tofino’s council split on ice rink decision

“I don’t think that’s the highest priority of the dollars that we have for a recreation facility.”

“Intense” storms coming to Tofino and Ucluelet this week

“If you are near the water, it is important to be ‘Coastsmart,’ by staying above the high tide.”

Ucluelet’s indoor market keeps vendors humming through the off-season

“It brings people out, which is great and we showcase different talents, which is great.”

WATCH: Giant waves smash Ucluelet’s Amphitrite Point

Folks made their way to Ucluelet’s Amphitrite Point Lighthouse on Thursday, Jan.… Continue reading

Transportation watchdog must revisit air passenger obesity complaint

Canadian Transportation Agency must take new look at Gabor Lukacs’ complaint against Delta Air Lines

Gas plants verdict coming down today; ex-premier’s top aides to learn fate

Verdict to be delivered on senior staff to former Ontario premier Dalton McGuinty

WestJet appeals lost bid to scrap harassment lawsuit

Airline argues judge was wrong to have dismissed the company’s application to strike the legal action

Can U.S. border guards search your phone? Yes, and here’s how

Secretary of homeland security explains a new policy that let’s border guards check phones

‘Beautiful writer’ Nancy Richler dies of cancer in Vancouver hospital

Montreal-born author spent most of her adult life in B.C. as a fiction writer and novelist

Jury convicts spear-wielding Duncan man in 2015 Ladysmith RV park murder

Trever George Meers used a handmade spear to stab Rayna Johnson at the Campers Corners RV Park

Students frustrated by UBCO response to harassment allegations

Students on the Kelowna campus were unaware of resources and worried about lack of communication

Opinion: Dare to be smarter

Just say no works for more than just substance abuse

Most Read