Record number of invasive strep A infections in Canada, 6 children dead in Ontario

What to know about spread of invasive strep throat Infectious disease specialist Dr. Brian Conway breaks down what to know about the severe strep throat virus in Canada.

Canada's public health agency has logged a record number of potentially deadly strep A infections, particularly in children under the age of 15. At least six children have died in Ontario.

"The concern is that it can be rapidly progressive and life-threatening," Dr. Kwadwo Kyeremanteng, head of critical care at The Ottawa Hospital, told CTV News Channel. "We've seen more cases of this in our intensive care unit, and the results have been pretty significant where people have lost their limbs, people have passed away."

As of Jan. 9, the Public Health Agency of Canada (PHAC) has received more than 4,600 invasive group A streptococcus samples from 2023, which is the highest annual total ever recorded in Canada and a more than 40 per cent increase over a previous 2019 peak of 3,236 samples. According to PHAC, invasive group A streptococcus is endemic in the country, with 2,000 to 3,000 cases reported annually in recent years.

"Early laboratory data indicates that [invasive group A streptococcus] disease activity in 2023 was higher compared to pre-pandemic years," a PHAC spokesperson said in an emailed statement shared with CTVNews.ca. "The largest increases continue to be detected in children under 15 years of age."

Infections from group A streptococcus bacteria are typically mild and can cause strep throat, which is usually treated with antibiotics. More severe and invasive infections are much less common, but potentially deadly.

Invasive group A streptococcus occurs when strep A bacteria causes a deeper infection that can lead to lung infections like pneumonia, debilitating flesh-eating disease, or even toxic shock syndrome, which is when bacteria produces toxins that cause organs in the body to stop functioning. Approximately one in 10 people die from invasive infections, according to a U.S. study. Serious outcomes can include amputation and major organ damage.

"An invasive infection really means the bacteria has moved to a site that should normally be sterile, such as the blood or under the skin in soft tissue or muscle," University of Western Ontario microbiology and immunology professor John McCormick told CTVNews.ca. "This is what is sometimes called the flesh-eating disease and can progress very quickly. These infections can present in different ways but severe pain that is out of proportion to what you see is a common symptom, or something that would suggest a spreading infection or skin colour changes."

A Jan. 11 report from Public Health Ontario says that 48 people have died from strep A infections in the province since October, including 23 people aged 65 or older and six children under the age of nine.

"This is higher than the proportion of [invasive group A streptococcus] cases within the same age group that had a fatal outcome reported in the same reporting period for the previous season… and exactly half of the total number of pediatric deaths reported in the entire 2022-23 season," the Ontario report said.

Provinces like B.C., Manitoba and New Brunswick have also reported a recent increase in cases.

Dr. David Fisman is a physician and epidemiologist, as well as a professor at the University of Toronto's school of public health. Fisman says that viral infections like COVID, influenza and RSV can make people more vulnerable to subsequent bacterial infections, which could be driving new strep cases.

"They seem to do this by killing some of the immune defences in the upper airway, 'setting the table' for invasive infection," Fisman told CTVNews.ca. "Canadians should be aware and appropriately concerned about this, as invasive group A streptococcal infections [as opposed to 'strep throat'] is a serious and life threatening infection."

Health officials say you should seek medical attention if you believe you have an infection.

Initial symptoms may include fever, sore throat and mild skin infections like rashes, sores and blisters. Streptococcus bacteria can be transmitted through direct contact with infected skin wounds, or from fluids in the nose and throat that can be spread when an infected person coughs or sneezes.

"Antibiotics are used to treat both invasive and non-invasive [group A streptococcus] diseases," PHAC explains. "Early treatment may make symptoms less severe or prevent more serious complications."

Kyeremanteng from the Ottawa Hospital says that when it comes to treatment, "time is of the essence."

"One of the main messages that I'm hoping to [get] across… is that if you are having signs and symptoms, not to ignore them and to seek medical attention as soon as you can," Kyeremanteng added. "The key is to have early antibiotics provided, and monitoring."

PHAC says invasive group A streptococcus has been "a priority for monitoring and control" by provincial, territorial and federal authorities for more than two decades, and that all cases "must be reported" to public health authorities.

"Group A streptococcal infections are complicated infections," Dr. Dale Kalina, chief medical information officer at the Brant Community Healthcare System in Brantford, Ont., told CTV News Channel. "It doesn't matter how busy your local emergency department is: if you're concerned, if you're feeling unsafe, if you have any of these red flag symptoms, come into the hospital, reach out for medical attention, that is why we're here."

"They seem to do this by killing some of the immune defences in the upper airway, 'setting the table' for invasive infection," Fisman explained. "Canadians should be aware and appropriately concerned about this, as invasive group A streptococcal infections (as opposed to 'strep throat') is a serious and life threatening infection."

Health officials say you should seek medical attention if you believe you have a group A streptococcus infection. Initial symptoms may include fever, sore throat and mild skin infections like rashes, sores and blisters. Streptococcus bacteria can be transmitted through direct contact with infected skin wounds, or from fluids in the nose and throat that can be spread when an infected person coughs or sneezes.

"Antibiotics are used to treat both invasive and non-invasive [group A streptococcus] diseases," PHAC explains. "Early treatment may make symptoms less severe or prevent more serious complications."

PHAC says invasive group A streptococcus has been "a priority for monitoring and control" by provincial, territorial and federal authorities for more than two decades, and that all cases "must be reported" to public health authorities.

McCormick from the University of Western Ontario is studying deadly streptococcus bacteria at his lab with the aim of finding a vaccine. He estimates that 10 per cent of school-aged children carry the bacteria without showing symptoms.

"Some of the new strains have a mutation that causes them to be more toxic which is very likely contributing to the bacteria causing more aggressive infections," McCormick said. "If you believe you have a strep infection such as strep throat with painful swallowing, fever, swollen tonsils or a rash, people should go and see their family physician. A rapid strep test can be done and if positive antibiotics should be used."

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