Cases of invasive meningococcal disease (IMD) are rising in some provinces, prompting health officials to warn Canadians about the serious risks and emphasize the importance of vaccination.
Last week, Toronto Public Health reported an increase in IMD cases since the beginning of 2024 in the region. So far this year, there have been 13 reported cases, surpassing the annual totals seen since 2002. Of those, two have been fatal, the agency stated.
This week, Manitoba reported a continuing spike in IMD cases since December 2023, while health officials in Kingston, Ont., warned of a rise in bacterial infection cases in February.
Several countries, including the United States, are reporting increases in cases of IMD this year, prompting health officials to warn that outbreaks of the disease can happen while travelling and in mass gatherings.
“Meningococcal is a potentially very dangerous bacteria. There are many different strains of it, some of which cause disease,” explained Dr. Ronald Gold, senior medical adviser of the Meningitis Research Foundation of Canada. “And you find them in maybe 20 per cent or 30 per cent of normal, healthy teenagers and young adults, they can carry the bacteria in their throat and they don’t get sick, but they can spread it to other people.”
He added that while teenagers and young adults appear to be the primary carriers of the bacteria, the reasons behind this phenomenon remain unknown.
In Canada, there are around 100 to 400 cases of meningitis reported every year, according to the Meningitis Foundation Canada, with the disease leading to fatalities in 10 per cent of all affected individuals. In Canada, infection often happens during the winter and spring months.
Young children under two are the most susceptible to IMD because they haven’t developed immunity yet, making them prone to the disease, Gold said. The elderly are also at increased risk.
What is invasive meningococcal disease?
IMD is a rare but serious bacterial disease with a relatively high case fatality rate and significant long-term effects, including limb amputations and permanent central nervous system injuries, according to the Public Health Agency of Canada (PHAC).
It is caused by the bacterium Neisseria meningitidis, which can cause meningitis (inflammation of the brain and spinal cord) as well as other severe conditions like blood infection and meningococcal pneumonia.
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There are different letters for different types of meningococcal, including A, B, C, Y and W. Meningitis B is the most common and deadly strain; it is rare but can lead to severe and life-threatening complications when contracted, PHAC stated.
“And when we say an invasive disease that means this bacteria, if you get it in your throat and you don’t have any immunity to it, it can invade into the bloodstream. And from the blood that can be an overwhelming infection itself is the most severe form of disease because it could go from somebody being perfectly normal to being dead within 24 hours,” Gold said.
“So it’s potentially one of the fastest fatal bacterial infections,” he added. Even if a patient receives antibiotics promptly, the damage to multiple organs can still be severe and fatal.
It also has the ability to infect the spinal fluid and membranes around the brain, causing meningitis, which can also be potentially fatal.
IMD is typically spread through respiratory droplets from coughing, sneezing, or close contact with an infected person.
“It does require very close direct contact between people because the spread is via droplets of saliva, kissing, sharing drinks, and things where you come into direct contact with the respiratory secretions of another person,” Gold said. “It doesn’t really spread very well through the air.”
This is why meningitis is so rampant among the military and university students, he said, because of the proximity in living quarters and sharing of personal belongings.
Why is it on the rise in some parts of Canada?
While Ontario and Manitoba are experiencing an increase in IMD rates, Gold explained that cases fluctuate unpredictably across the country.
“It’s happened in almost every province and territory at some point. There has been an increase. Often it may be one group like serogroup C becomes more common all over the country,” he said.
In Manitoba, the current serogroup that is spreading in the province is W, according to provincial data. And in Ontario, it is a mix, Dr. Chrstine Navarro, a physician at Public Health Ontario, told Global News.
“In Ontario, we always have some sort of a wide range of serogroups. The ones that we see in Ontario are serogroup C… we also see serogroup W, serogroup Y and serogroup B and rarely serogroup A, and occasionally one set may not fall into one of those categories.,” she said.
“We do have every year, a mix of all of those serogroup. And there can be a lot of variation not only across the country but even within a province, sort of what is circulating. And that changes over time.”
Symptoms of IMD develop two to 10 days after exposure, according to Health Canada. They can include:
- sudden fever
- drowsiness
- irritability or fussiness
- intense headache
- vomiting
- stiff neck
- a skin rash that spreads rapidly and begins as reddish and purplish spots that don’t disappear when pressed.
Severe cases can result in hallucination, coma and if untreated can lead to death, Health Canada warned.
“For the appearance of multiple symptoms, it is important for a person to be seen urgently, they should be seen in an emergency department to be assessed, immediately,” explained Navarro.
Vaccines can prevent IMD caused by five types of meningococcal bacteria A, B, C, Y and W.
In Canada, there is a meningococcal quadrivalent vaccine (which covers groups A, C, Y and W) for meningitis. However, this routine vaccination doesn’t protect against meningitis B. To safeguard against that strain, another vaccine is required, which costs money and requires a request from one’s family physician
The Canadian Paediatric Society (CPS) said there are currently three kinds of meningococcal vaccine available in Canada. Each vaccine provides different protection:
- Meningococcal C vaccine (Men-C-C) is usually given to babies and young children. It protects against type C of the meningococcus germ, which used to be very common before this vaccine was available.
- MCV-4 protects against 4 types of meningococcal germ (A, C, Y and W135). This vaccine is usually only given to people at higher risk of getting meningococcal disease (those with no spleen or who have certain medical conditions). In some provinces it is given to all teenagers.
- Meningococcal B vaccine (Men-B) protects children against type B. This vaccine is not given routinely but is usually given to children at higher risk of getting meningococcal disease.
Children should be immunized with Men-C-C at 12 months of age, CPS said. Teenagers should get a dose of MCV-4 or Men-C-C, usually at about 12 years of age. And it is recommended that children at higher risk for meningococcal disease (children with no spleen or who have certain medical conditions) should receive MCV-4 and Men-B vaccine starting as early as two months of age.
The B vaccines (a series of shots) have been shown to be effective in inducing antibodies that kill at least 80 per cent of group B strains, according to Meningitis Foundation Canada. The number of required doses varies based on the specific vaccine.
It is not included in Canada’s standard vaccination regimen, except in Nova Scotia and P.E.I. The cost varies by province; for instance, it is $130 per dose in British Columbia and $125 per dose in Ontario.
The vaccine is recommended for anyone between the ages of two months to 25 years of age.
