How Ontario became the measles centre of the west

Outside the emergency room of the St Thomas Elgin general hospital, about 200km south-west of Toronto, a large sign in bright yellow block letters reads: "NO MEASLES VAX & FEVER COUGH RASH - STOP - DO NOT ENTER!

- Olivia Bowden ST THOMAS

To see such an imperative in the 21st century might have been previously unimaginable for Canada, which in 1998 achieved "elimination status" for measles, meaning the virus is no longer circulating regularly.

But now Canada is at risk of losing that status due to an explosive outbreak of the highly infectious and sometimes deadly disease in south-western Ontario, where the hospital is located.

Since October, the province has reported 2,009 cases of measles associated with the current outbreak - more than all of those in the United States combined in 2025, and making Ontario the measles centre of the western hemisphere.

Cases have been climbing by the hundreds over the past month, and three-quarters are in unvaccinated children, according to Public Health Ontario.

June saw the first fatality from the outbreak: a premature baby who contracted measles in utero from their unvaccinated mother. Ontario's chief medical officer of health, Kieran Moore, said the infant had other unrelated medical complications, but confirmed that measles may have been a contributing factor in both the premature birth and death.