Alberta experiences late-season flu spike

Influenza cases have spiked in Alberta in recent weeks, marking a return of the illness after zero confirmed cases in the province last year.

Alberta's chief medical officer of health, Dr. Deena Hinshaw, said Wednesday during a COVID-19 update that there have been 707 cases of seasonal influenza recorded in the province this year.

Data online show a large number of those cases were lab-confirmed in April.

There were more than 8,000 lab-confirmed cases in the 201920 season.

“In Alberta, we have had more than 700 cases diagnosed this season, with the vast majority identified in the past two months,” said Hinshaw.

“Actions to lower the risk of influenza infection are the same as those we need to continue for COVID — washing our hands regularly, staying home if sick and, for those at higher risk of severe outcomes, considering actions like wearing masks when in public places.”

A total of 68 people in Alberta have needed hospital care, including three who were admitted to intensive care.

No one has died from the flu this year.

Dr. Jia Hu, a public health physician, said a number of respiratory illnesses appear to be flaring up in the province as people begin to interact with each other more often.

“What people are doing now is they're hanging out more, which is actually really good for people. But that brings back the flu. All the other respiratory viruses are back as well, you know, things like RSV,” said Hu.

“The other factor that I think is really interesting about this is because we didn't have any flu in the 2020-21 season, our vaccine uptake fell by quite a lot.”

This season, there have been just over 1.2 million flu shots administered in Alberta, according to data posted on the government's website.

Last year at this time, there had been more than 1.6 million doses administered.

Hu said that while Alberta typically has a low uptake, people's level of worry regarding a disease will affect the steps they take to protect themselves against it.

“Nobody should have any immunity right now from natural infection. So I think it'll be important for people to get vaccinated against flu in the fall,” said Hu.

Of the 707 cases in Alberta, 236 are in the Calgary zone while another 208 are in the South zone. Hu said Calgary typically sees cases before the rest of the province.

He said it is unclear why that occurs but that city density or international travel may play a part.

He said Calgary is often an indicator of what could happen in other parts of the province but noted this flu season is already close to being over, warning that Alberta's largest city may be showing early signs of what the next flu season may bring.

Alberta Health spokeswoman Lisa Glover said the spike late into the season is unusual but is not unique to Canada, with the United States and parts of Europe also experiencing a rise.

“This is not unexpected as jurisdictions begin to lift COVID -19 measures. Measures that have helped prevent COVID-19 transmission are also effective against influenza, which is much less transmissible,” said Glover.

She noted the 707 cases have been lab-tested to inform treatment, and it is expected there are more cases in the community.