Canada's loss of measles-free status a setback, but 'reversible': health official

Canada's measles-free position revoked, says wellness Canada

Despite outstanding efforts made in Canada, the rural area has lost its measles elimination status and the virus is now considered endemic, said Dr. Jarbas Barbosa, director of the Pan American Health Organization (PAHO), in a media briefing held this morning.

The public health body made its decision about Canada after carefully reviewing the country’s epidemiological data, Barbosa said. It represents a setback, he added, but it's "also reversible" by keeping the country measles-free and increasing immunization coverage.

Canadian officials are “firmly committed” to achieving elimination again, Barbosa said.

"Measles is the most contagious virus known to humankind. One infected person can transmit the disease to up to 18 others. Thanks to vaccines, most people have never seen an outbreak in their lifetime," PAHO’s director told reporters.

He also stressed that when one country in the region has lost its elimination status, the region as a whole loses its status, and he warned of the ongoing risks of imported cases of measles from other regions.

Measles isn't just highly contagious, it's also incredibly dangerous.

Early on in an infection, people may experience a high fever, cough and runny nose — not unlike other, milder illnesses. Then comes the telltale rash: Red or purple, depending on someone's skin tone, the blotchy rash spreads over the body and can last up to a week.

Measles can also lead to a range of life-threatening complications, including pneumonia, brain swelling, even death. In some cases, it leads to a devastating, deadly brain disease that develops years after an initial infection.

The risks aren't as rare as you’d think.

U.S. Data shows roughly one in five unvaccinated individuals who get measles need to be hospitalized, and up to three in 1,000 children who catch the virus die. (Complications are more likely in high-risk groups such as young children under the age of five and people who are pregnant or immunocompromised.)

Graeme Bruce here, I’m a graphics and data producer. There have been more than 5,000 total cases of measles in Canada this year, as of Oct. 25, according to the Public Health Agency of Canada’s database, most of which were reported in Ontario and Alberta.

The staggering number caps off a 27-year run of Canada holding the measles elimination status, which it lost today.

While the 2025 number is dramatic, the weekly number of news cases has significantly decreased from the high seen in the spring.

The Public Health Agency of Canada has said it considers Oct. 27, 2024, the starting point of Canada's current measles outbreak, which has climbed to more than 5,100 confirmed and probable cases of the highly contagious virus that spreads in the air.

Public health officials say it started when an international traveller attended a wedding in New Brunswick last October. New Brunswick's outbreak ended in January, but guests at that wedding had already brought the virus to southwestern Ontario, where that province's outbreak was concentrated among closely knit Mennonite communities.

The same strain of measles virus went on to cause infections in nine provinces and one territory, according to federal health officials.

Canada's measles-free status revoked, says Health Canada

The Pan American Health Organization has notified the Public Health Agency of Canada that Canada no longer holds measles elimination status, says Health Canada. The health agency says that while 'transmission has slowed recently, the outbreak has persisted for over 12 months.'

What does losing this status mean for Canada? Infectious disease specialist Dr. Isaac Bogoch believes the consequences are twofold: it "bruises" the country's public health reputation and "it's a giant wake-up call that we have gaps in our public health infrastructure."

"We need to fill those gaps, and we need to do so urgently," the infectious diseases specialist said. "Canada should be a leader — a global leader — in public health."

While Canada does have a strong public health network, Bogoch says he hopes the loss of this status will lead to better programs and increased funding that will lower barriers to vaccine access and improve outreach and trust.

He believes misinformation and disinformation — deliberate efforts to subvert public health — are factors in the reduction of vaccination rates in the country.

"We've seen this play out in multiple areas of public health, and that's a difficult issue to contend with," Bogoch said.

Global guidelines define measles elimination as the "interruption of endemic measles virus transmission" for at least 12 months straight, alongside high-quality surveillance. Achieving that is no easy feat.

The measles virus is still circulating worldwide and often hitches a ride with travellers, meaning cases do regularly get imported into countries like Canada. The key is stopping the virus before it spreads.

Once measles transmission continues beyond a 12-month period — like it has in Canada over the last year — then the virus is considered endemic, and no longer "eliminated" in the country.

We’re still waiting to hear from Pan American Health Organization officials later this morning about what exactly led to their decision.

For the week ending Oct. 25, the latest available, the federal government reported 29 new measles cases in Canada, all confirmed.

Saskatchewan currently has the most new cases with 11, followed by B.C. With nine. Ontario declared an end to its large outbreak a little over a month ago, on Oct. 6. Alberta, which also had a large outbreak, currently has seven cases.

While measles elimination status is symbolic, doctors say the loss represents increased risk across the region of the Americas because communities and public health haven't achieved control of long chains of transmission, like spreading beyond single digits in a family.

Low vaccination rates with the measles, mumps and rubella (MMR) vaccine, which has a long safety record, is the main driver of spread, both federal and provincial public health officials have said.

Around the world during the COVID-19 pandemic, various countries experienced setbacks in measles surveillance and vaccination efforts — Canada included.

That's a big problem, since measles is the most contagious (yet vaccine-preventable) disease in the world, and uptake rates as high as 95 per cent are needed to curb transmission and prevent outbreaks.

But in many pockets of the country, vaccination rates in recent years have fallen far short.

The measles, mumps and rubella (MMR) vaccine for children comes in two doses. Coverage for the first dose decreased from about 90 per cent in 2019 to around 83 per cent in 2023, according to PHAC. For the second dose, it fell from about 86 per cent to around 76 per cent over the same time period.

Vaccination rates have been even lower in certain communities. In Quebec, for instance, some schools in the Montreal area had uptake as low as 30 to 50 per cent, officials said last year.

It's been a similar situation in Alberta as well, with uptake as low as 29 to 40 per cent in some areas. Once measles reaches communities like that, it often spreads like wildfire.

Canada gained its status of having eliminated measles in its general population in the 1990s, following successful outreach and public health programs to vaccinate people "such that when we saw imported cases of measles, we wouldn’t see sustained chains of transmission," said Dr. Isaac Bogoch, an infectious diseases specialist in Toronto.

"This is the most transmissible virus we know of. It's going to ultimately find non-immune individuals. And that's exactly what happened," he said.

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