Guardian Outside the emergency room of the St Thomas Elgin general hospital, about 200km (125 miles) south-west of Toronto, a large sign with bright yellow block letters issues an urgent warning: “NO MEASLES VAX & FEVER COUGH RASH – STOP – DO NOT ENTER!”
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.
Now, however, Canada is at risk of losing that status – mainly because of an explosive outbreak of the highly infectious and sometimes deadly disease in south-western Ontario, where the St Thomas hospital is located.
Since October, the province has reported a staggering 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.