Measles has exploded in Europe. Clinicians say it's only a matter of time before outbreaks hit Canada

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After an explosion of measles cases in Europe, medical experts say it's just a "question of time" before outbreaks happen in Canada, thanks to high rates of global travel and low rates of vaccinations.

There were 42,200 measles cases across more than 40 European countries last year, the World Health Organization (WHO) announced this week — a more than 40-fold increase from 2022, which saw fewer than 1,000 cases. In December, the organization said there had been more than 20,000 hospitalizations and at least five deaths in the European region.

Globally, the situation is even grimmer, with a spike in infections in 2022 that included nine million known cases and 136,000 reported deaths, mostly among children.

The WHO said the rise in cases in Europe has accelerated in recent months, and the upward trend is expected to continue if urgent measures — like vaccination efforts — aren't taken to prevent further spread of this potentially deadly infection.

"It's not something that is mild," said Dr. Kate O'Brien, a Canadian pediatric infectious diseases specialist and director of the WHO's department of vaccines and immunization. "And it's not something to be taken lightly."

Canada eliminated measles back in 1998 through widespread vaccination programs.

Here, the vaccine is given to children as two doses of a combined shot that also protects against a combination of infections — either measles, mumps and rubella, or measles, mumps, rubella and varicella. 

The annual case count remains small — only a dozen confirmed infections were reported country-wide in 2023 — and most cases are now acquired through travel outside the country.

But clinicians say outbreaks are still a risk. Canada, like many other countries, hasn't hit the 95 per cent vaccination coverage required to prevent its spread.

"Measles is probably the most infectious human virus that is known, and as a result, in order to prevent measles infections, vaccination rates have to be really high in a community," said O'Brien. 

"What's happened is, over the course of the pandemic, we've had a historic backsliding in the immunization rates around the world."

In Europe, the level of coverage with two doses of the measles vaccine dropped from 92 per cent in 2019 to 91 per cent by 2022, WHO data shows. Nearly two million infants also missed their measles vaccination in the first two years of the pandemic. 

That means children are particularly at risk, clinicians say. Measles spreads easily through the air, leads to high hospitalization rates, and can cause a hacking cough, high fever and a prominent rash. In more serious cases, it leads to pneumonia, brain damage, and death in up to three out of every 1,000 children infected.