Canada Faces Loss of Measles Elimination Status After Yearlong Outbreak Infects Over 5,000

Canada is waiting to learn whether it will keep a distinction it has held since 1998. Health officials said this week that a measles outbreak lasting a full year, with more than 5,000 people infected and two infants dead, has put the country's measles elimination status in jeopardy.

The outbreak began in October 2024 in New Brunswick and has since spread across multiple provinces. It is the first continuous transmission of measles in Canada in more than 25 years, which is why the elimination status is now in question.

The rule for losing that status is specific. Daniel Salas, an immunization expert with the Pan American Health Organization, told NBC News that a country must have 12 months of continuous transmission of the same genotype and the same strain of the virus before it can be said to have lost elimination. Canada's outbreak has now reached that mark.

PAHO is part of the World Health Organization. It meets next week in Mexico City to review the data and decide whether to strip Canada of its measles-free status. If the status is revoked, officials said, Canada will have to carry out a "corrective action plan" to regain it.

Dr. Isaac Bogoch, an infectious disease specialist at the University of Toronto, told CTV News that the possible loss is "a wake-up call that we need to do better in vaccinating our general public so we don't have outbreaks like this."

The United States may be on a similar path. The CDC has reported at least 1,618 measles cases there so far this year, the most since the disease was declared eliminated in the country in 2000. The current American outbreak began in West Texas in January and infected more than 800 people across Texas and New Mexico. It has since spread to other states, including Arizona, Utah and South Carolina. Three deaths have been confirmed, including two young girls.

The U.S. is unlikely to lose its status at the upcoming PAHO meeting, because its outbreak began less than 12 months ago.

The tool for prevention is well established. According to the CDC, the measles-mumps-rubella vaccine prevents infection in 97% of people after two doses, typically given around ages 1 and 5.

Salas described the elimination of measles in the U.S. and Canada as "a huge achievement." When the region sustains elimination, he said, it also acknowledges each country's efforts. Next week's meeting in Mexico City will show whether Canada's efforts are still counted, and the same 12-month test will apply to the U.S. if its transmission continues.