TORONTO - Ontario is reporting its highest weekly increase in measles cases since its outbreak began with 223 new infections in the province over the past week, as opposition parties and some doctors call on the province to do more to address the public health crisis.
The latest Public Health Ontario data released Thursday brings the total number of people in the province who have fallen ill from the virus to 1,243 since October. That includes 84 people who have been hospitalized 鈥 including 63 children 鈥 during the course of this outbreak. Eight patients have been admitted to intensive care.
The measles crisis entered the political ring at Queen’s Park Thursday with Ontario Health Minister Sylvia Jones standing by the province鈥檚 chief medical officer of health, as opposition leaders suggested Dr. Kieran Moore should address the public and the government should be taking a stronger approach.
Asked why the public hasn’t recently heard directly from Moore, Jones told reporters he has been working closely with public health units behind the scenes.
“He’s been working incredibly hard,鈥 she said.
鈥淚 have repeatedly reminded people that it was over a year and a half ago that actually it was Dr. Moore that directed the public health units to ensure that they refocus their efforts to ensure that childhood vaccinations were up to date.”
Moore didn鈥檛 immediately respond to a request for comment.
Ontario NDP Leader Marit Stiles said the government is making measles a political matter.
“The government鈥檚 response has been that this is an ideological thing, like we鈥檙e making it political. Well, you know what? It is a political issue right now. We need people to understand the importance of immunization.鈥
Ontario Liberal Leader Bonnie Crombie called the government’s approach “deeply concerning.”
“This is spreading and it needs to be taken seriously,鈥 Crombie said.
WHAT THE LATEST DATA SHOWS
Dr. Sarah Wilson, a medical epidemiologist at Public Health Ontario, said it鈥檚 鈥渏arring鈥 to see these numbers after several weeks of cases in the 100 range, and that it will be important to monitor what happens next.
鈥淲as this past week an anomaly? Next week, will we be back to the 100, or closer to the 100 range? I think we have to look at this from a longer-term perspective,鈥 Wilson said.
She said this increase is because of the 鈥渧ery significant鈥 measles transmission in unvaccinated pockets of the province, concentrated in southwestern Ontario, primarily infecting infants, kids and teenagers.
Public Health Ontario noted that its southwestern public health unit has had 57 new infections, compared to 15 the previous week. Neighbouring Grand Erie Public Health is also seeing an uptick with 46 cases, compared to two the previous week.
Southwestern Public Health’s Dr. Ninh Tran said this 鈥渟harp rise鈥 is due to exposures in large unvaccinated households between siblings and other family members, and places where unimmunized people gather.
He said the increase in cases is not tied to any particular event and he did not pin the spread to a particular group.
Tran said the duration of hospital stays on average is usually just over three days, and ranges from about one to 11 days.
PHYSICIANS RESPOND
Dr. Iris Gorfinkel, a family physician in Toronto, said there鈥檚 so much more the province could be doing to stamp out the spread, such as launching a big public health campaign to inform parents how to identify measles.
Tran did this during his update Thursday, reminding parents that the characteristic rash typically associated with measles is not the first symptom of the illness. It is one of the last symptoms, he said, noting parents should keep unvaccinated kids home if they have respiratory, gastrointestinal or pink-eye symptoms.
A national vaccine registry would have allowed public health officials to get ahead of the outbreak by identifying unvaccinated parts of the province 鈥 which have become measles hotspots 鈥 and targeting vaccination efforts in those areas before the outbreak spread, Gorfinkel said.
鈥淲hat would happen is that we would be able to identify those individuals who needed vaccination prior to their getting sick,鈥 she said.
Gorfinkel said Moore is 鈥渕issing in action鈥 during the largest outbreak in decades when he should be making public appearances and reaching out to physicians, considering most doctors have never seen a case of measles.
鈥淭his is infectious disease 101.鈥
Infectious diseases specialist Dr. Isaac Bogoch said community outreach is key in any outbreak 鈥 whether its measles or mpox.
He said that can be done through local public health units hosting town halls, public health messaging at community centres and places of worship, going to popular restaurants where people congregate, having a physical presence and answering questions.
“This is an outbreak that’s going to continue to burn until it hits a wall of immunity. And the wall of immunity can come in one of two ways. It can come by ripping through a non-immune population, which is obviously the wrong way to do it, or by lowering barriers to vaccination and ensuring that there is high rates of immunity through vaccination in the community, in which case it’ll fizzle out,” Bogoch said.
This report by The Canadian Press was first published May 1, 2025.
Canadian Press health coverage receives support through a partnership with the Canadian Medical Association. CP is solely responsible for this content.
To join the conversation set a first and last name in your user profile.
Sign in or register for free to join the Conversation