Canada is seeing a record number of invasive strep A cases: Here's what you should know about the disease

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Canada is seeing a record number of cases of invasive Group A strep, according to government data cited by CBC News.

There were more than 4,600 cases confirmed in 2023 at the National Microbiology Laboratory in Winnipeg. It's an increase of 40 per cent compared to the previous record high in 2019, according to the Public Health Agency of Canada (PHAC).

The news comes on heels of Public Health Ontario reporting there were 48 deaths between October and December, including six cases of children aged nine or younger. New Brunswick has also reported two deaths already in 2024, including a child under the age of nine and a person within the ages of 10 to 59.

Ontario's data indicates around three-quarters of people with a confirmed case of invasive Group A strep (iGAS) end up going to the hospital. In December alone, there were 222 cases reported, more than any other month for the province.

Other provinces and parts of the world are also seeing a spike in the disease. B.C.'s Centre for Disease Control announced in December the province was seeing higher levels of infections compared to historical levels. Quebec reported a 55 per cent rise in cases last year over pre-pandemic levels, and Manitoba noted it had 200 confirmed cases in 2023.

In December 2022, the World Health Organization urged people in Europe to take caution after a spike in cases and deaths. The U.S. Centers for Disease Control alerted people of cases amongst kids that same month.

A seven-year-old named Taitlyn from Vancouver underwent surgery to amputate her lower right leg and left toes in August 2023. Her father, Terry Ma, told Yahoo Canada she had been hospitalized for more than two months after contracting iGAS.

The doctors told Ma at the time "she is very sick and might not make it. ... No parents ever want to hear that." Taitlyn had a long road to recovery, and her father warned parents at the time to hit the "panic button" as soon as something seems off.

"Pay close attention to your child. ... You don't want to be too late," Ma previously told Yahoo Canada.

But what signs should be parents be looking out for when it comes to iGAS, and when should you worry?

Two experts recently told Yahoo Canada Canadians don't need to "lose sleep" over the recent spike in invasive strep cases, but they should be informed. They added the spike could likely be due to the removal of COVID-19 pandemic restrictions and a lack of immunity in children.

Here's what you need to know.

What is invasive group A streptococcus (iGAS)?

Group A streptococcus (GAS) is a common bacterial infection that grows inside the nose, throat and sometimes on the skin. It most often affects children and seniors, but anyone can have it.

Toronto infectious disease specialist Dr. Anna Banerji said it often causes strep throat and sinus infections, and it can escalate and cause issues like ulcers.

But, if it goes into a person's bloodstream it can serious conditions, including meningitis and toxic shock syndrome — which could become fatal.

Group A streptococcus is common, and "is more severe than other types of streptococcus," Banerji told Yahoo Canada.

But the invasive type — one that enters the bloodstream — is less common and causing concern.

Why are we seeing a spike in invasive strep cases?

Banerji explained there are several reasons for the increasing case numbers of iGAS — including some "post-pandemic" behaviours.

"We were all practicing public health measures before with masking and strep, that's in the throat, is generally spread by droplets. If you use masking, then you reduce the spread," she said.

"In the fall, when the kids when back to school and took off their masks, a lot of viruses and bacteria spread."

But, Banerji said many kids also hadn't been exposed to strep previously because of the pandemic restrictions, and "didn't have a lot of immunity." That's why younger patients tend to have more severe strep.

The expert said while strep lives in the throat, any virus infection could cause strep symptoms to develop.

"Because we had a horrible viral season this fall, we also saw more strep than usual."

John McCormick, a professor of immunology and epidemiology at Western University, says research now shows about 10 per cent of children will carry strep in their throats without any problems.

"But sometimes it does," he said. In the "rare" case of invasive strep, the bacteria can become "quite dangerous."

Though case numbers are increasing, they're not high and "it happen to essentially anybody."

McCormick echoed Banerji in saying the lack of immunity in children is likely the reason behind the recent spike.

"When there's less transmission, there's less strep," he added.

What Canadians should know about invasive strep

Should the average person worry about the recent spike in invasive strep? McCormick said no, but addded Canadians should stay informed.

"Mortality rates from invasive streptococcal disease ... can be quite high," he said. "That would obviously be the worst consequence."

However, other severe consequences can include the need to remove tissue and even amputation, according to McCormick.

"In general, people should not be really that worried," he said. "But they should just be ... using common sense."

McCormick said if your child is experiencing what looks like strep throat, they should see a health care professional and get diagnosed.

"If they have strep throat, (parents) probably shouldn't be sending their kids to school. If you have any kind of an open cut or sore, you should be using normal hygienic practices," he explained.

"If you have these types of symptoms, you shouldn't ignore them."

Banerji agreed.

"I don't think the average Canadian should lose sleep, cause we've just been through a major pandemic and it doesn't compare to (the strep increase)," she said.

"If you are sick, stay home because you don't want it to spread," Banerji advised. "The main thing is trying to reduce spread."

For those who are diagnosed, her advice is to "start the antibiotics early."

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