Annual cases of invasive meningococcal disease (IMD), a rare but dangerous bacterial infection, have hit the highest level seen in Canada in more than a decade.
This rapidly progressing illness is known for causing a host of serious complications, including meningitis — a swelling of the membranes around the brain and spinal cord — alongside bloodstream infection, sepsis, severe organ damage and even long-term disability or death.
Infants and young adults have some of the highest death rates, federal data shows.
“That’s a very significant consequence and very serious disease at such a young age,” said Dr. Cristin Muecke, a regional medical officer of health at Nova Scotia Health. “And so from that perspective, even though it is rare, the consequences are quite high.”
While annual case counts dropped dramatically after the rollout of meningococcal vaccines in the early 2000s — and they hit a record low in 2021 amid the sweeping restrictions of the COVID-19 pandemic — recent Canadian public health data shows a steady return of IMD.
There were 48 country-wide cases of IMD in 2021, 74 in 2022 and nearly 100 in 2023, according to figures from the Public Health Agency of Canada.
Preliminary provincial data compiled by CBC News shows a bigger jump since then, with at least 132 cases in 2024 and 155 in 2025 — marking the country’s highest tally since 2012. There have also been at least 63 cases across Canada’s 10 provinces so far this year. Data from the three territories wasn’t requested because the numbers are usually low due to population sizes.
While a post-pandemic rise in IMD cases wasn’t a surprise to infectious disease specialist Dr. Allison McGeer given the range of diseases that returned to typical levels in recent years, she said these bacterial infections are particularly challenging due to their severity.
This disease is also hard to predict, McGeer said. It’s caused by a range of bacterial subtypes that appear at varying levels in different provinces, sparking occasional outbreaks that seem to come out of nowhere.
“What’s unnerving about invasive meningococcal disease is that we’ve had several changes in epidemiology over time … that we don’t have good explanations for,” said McGeer, a senior clinician scientist with the Toronto Invasive Bacterial Diseases Network at Mount Sinai Hospital.
IMD has a death rate of 14 per cent in Canada, with infants and young adults among those most at risk of fatal outcomes. Another 15 to 20 per cent of people infected have long-term health impacts such as hearing loss, limb amputations or neurological disabilities.
The disease is spread through Neisseria meningitidis, a common bacteria that’s carried harmlessly by roughly one in 10 people. Six subtypes — meningococcal A, B, C, X, W and Y — are known for most often causing invasive forms of this infection.
In those cases, bacteria manages to enter the bloodstream, bypassing the immune system and leading to a sudden, severe illness.
That’s what Jason Fryza and Sandy Hilmarsen recall their daughter Leah experiencing in April 2024. The 11-year-old had been diagnosed with a basic ear infection, but just hours later, she had a rising fever and worsening headache, then started vomiting repeatedly.
“We looked at her and … something just didn’t seem right,” Fryza said.
The Thompson, Man., parents ended up rushing their daughter back to the nearest hospital.
Leah was later diagnosed with life-threatening bacterial meningitis and flown to the HSC Children’s Hospital — more than 650 kilometres away in Winnipeg — where clinicians discovered she also had a blood clot in her brain.
She ended up spending 10 days in hospital as medical teams gave her intensive treatment, including multiple MRIs and broad-spectrum antibiotics, her parents said. She’s since made a full recovery.
“We are grateful that they were able to recognize what was going on,” Hilmarsen said.
Manitoba has seen above-average case counts of IMD over the last three years amid an outbreak of meningococcal W that’s largely impacting young people in Winnipeg and Indigenous communities in northern parts of the province.
In 2025, there were four deaths out of 23 cases, an annual tally roughly five times higher than usual, Manitoba health officials said in January.
While most provinces aren’t seeing a major rise in IMD, several other regions are also experiencing a recent uptick in infections and deaths.
Saskatchewan’s annual IMD case count jumped from four in 2024 to 17 in 2025, with three infections reported so far this year, according to provincial data provided to CBC News.
Meanwhile, public health data in Ontario shows there were six fatal cases out of 30 total infections recorded in 2024, while preliminary data shows there were 39 cases for 2025 and another 42 so far this year.
In Quebec, there were fewer than five deaths — the province withheld the exact number for privacy reasons — out of 53 total cases in 2024, along with six deaths and 47 cases in 2025 and another 10 cases so far in 2026.
Toronto infectious disease specialist McGeer said it’s not clear why some parts of the country, such as Manitoba, are experiencing more cases than others.
The spread of the W subtype through parts of the province is also distinct, she added. “Is it going to spread around the world? Is it specific to Manitoba for some reason? And the answer is: We don’t know.”
The province has shifted its meningococcal vaccination strategy to tackle the outbreak, allowing children to get a vaccine that covers four subtypes of meningococcal bacteria at the age of one. Before 2024, children had to wait until Grade 6 for that shot, Manitoba’s chief provincial public health officer, Dr. Brent Roussin, recently told CBC Manitoba.
Currently, Canada recommends various vaccines that cover different bacterial subtypes — including the four-subtype shot that offers protection against meningococcal A, C, W, and Y, and different vaccines that protect against subtypes B and C.
A meningococcal C vaccine is usually given to babies and young children, while the shot offering protection against the four subtypes is typically given to higher-risk groups or, in some provinces, to all teenagers.
The meningococcal B vaccine is usually given only to kids at a higher risk, and again, its use varies between provinces — forcing some Canadian families to rely on private insurance or pay out of pocket to get the shot.
In Nova Scotia, vaccination strategies also changed in the wake of a 2022 outbreak of IMD caused by meningococcal B, which led to the death of a student at Dalhousie University.
The province started offering the meningococcal B vaccine for free to young adults living in congregate settings, such as university dorms or military barracks, said Muecke, the regional medical officer of health with Nova Scotia Health.
Muecke stressed that each province needs a tailored approach, given the striking differences in IMD subtypes and rates of infection between regions.
“While it’s instructive to look at what happens in other provinces and in other countries … we do have to be quite intentional about looking at what’s specifically going on in our area,” she said.
Overall uptake of meningococcal vaccines has also dropped in Canada, adding another complication for health teams trying to manage this challenging disease.
Coverage for the meningococcal C vaccine declined from more than 90 per cent of children up to the age of two in 2019, to less than 84 per cent by 2024, federal data shows.
Vaccination coverage for the four-subtype shot among teenagers has also dropped since the pandemic.
“It’s very worrisome that our coverage rates have changed,” said Dr. Joanne Langley, a pediatric infectious disease professor in the faculty of medicine at Dalhousie University in Halifax and the senior medical director of Meningitis Foundation Canada.
Langley attributes the drop to a mix of factors, including less accessibility during the COVID-19 pandemic, vaccine hesitancy and a lack of primary care providers in many regions.
Despite those hurdles — and the fact that no one shot protects against all meningococcal subtypes — she stressed that these vaccines remain the best way to protect children and young adults from developing IMD.
In rare cases where young people contract this serious infection, multiple experts said it’s important to know the warning signs and act fast, since someone’s condition can deteriorate within hours.
“It can start off looking a lot like many infections. You get a fever, a headache, you don’t feel well, you might feel nauseous,” Muecke said. “But it can then, unfortunately, develop quite quickly into a more serious condition.”
Red flags that signal a serious infection in the brain or blood can include an intense headache, a stiff neck, feeling sensitive to light, being confused or unusually drowsy or having the onset of a full body rash.
“Parents are the best advocates and the best able to perceive when something’s wrong with their child,” Langley said. “So if your child is different — if you’re worried — pursue getting the care they need.”
