Health authorities in Ontario’s Peel Region are probing a newly reported case of measles, saying some travellers who were at Toronto Pearson Airport last weekend may have been exposed to the airborne disease.
Exposure is believed to have occurred May 3 on Toronto-bound flight AC540 from Seattle, Peel Public Health (PPH) said in a May 7 release. Those who were in the area of Terminal 1 between 7:28 p.m. and 10 p.m. may also have been exposed to measles, the health department said.
PPH is advising anyone who was at the exposure sites to confirm they and their family members are up-to-date with their measles vaccinations and to monitor themselves for possible symptoms until May 24.
“Peel Public Health directly contacts people who were at exposure sites if possible,” the department said. “Anyone experiencing symptoms should contact their health care provider, or if not available, Peel Public Health as soon as possible to get advice. Do not attend work or school.”
Measles is a highly contagious disease that poses the risk of serious health complications. It spreads more easily to those who have not been vaccinated for measles or have not previously had the disease, with symptoms appearing seven to 21 days after infection, PPH said.
Symptoms of measles can include fever, cough, runny nose, and red, watery eyes. The condition is typically accompanied by a rash that manifests in red spots and blotchy patches that start on the face and then spread down the body, arms, and legs.
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Measles can also lead to serious complications including blindness, severe breathing problems including pneumonia, and encephalitis, an infection causing brain swelling and potentially brain damage, according to the World Health Organization (WHO).
Complications are most common in children younger than five, adults older than 30, and in pregnant women, the WHO said. If a woman contracts measles during pregnancy, this can result in her baby being born prematurely with a low birth weight.
Measles Spreading
Measles was eradicated nationwide in 1998 due to vaccination, but since the disease remains endemic in other parts of the world, travel-related cases continue to be seen in Canada, says Infection Prevention and Control Canada (IPAC).
“Due to an increase in measles activity globally Canada has begun to see more travel-related cases,” IPAC said. “These cases can spread rapidly in underimmunized communities.”
There have been six confirmed cases of measles in Peel so far this year and there were three cases in 2024, PPH said. Out of Peel’s six cases, three were associated with travel, while the remaining three stemmed from close contacts or community transmission.
Peel’s cases have not been linked to the ongoing multi-jurisdictional measles outbreak in Ontario, the department said.
Ontario currently leads the nation in reported measles cases with 993 confirmed in the province this year as of April 19, according to Health Canada data.
Ontario Public Health said the province’s multi-jurisdictional measles outbreak was traced back to a travel-related case in New Brunswick last October.
“Ontario and additional provinces have reported measles cases related to this outbreak,” Ontario Public Health said, noting that New Brunswick’s outbreak officially ended in January.
“The increase in the number of outbreak cases and the geographic spread in recent weeks is due to continued exposures and transmission among individuals who have not been immunized.”
There have been 1,019 confirmed and 158 probable cases of measles so far this year in Canada.
After Ontario, Alberta has had the second highest incidence of measles with 120 cases followed by Quebec with 36.
