Almost 90 per cent of Ontario’s growing measles cases are in the southwest

Measles cases in Ontario are continuing to rise, with the majority of cases concentrated in southwestern Ontario, according to recent data released by Public Health Ontario (PHO). The outbreak, which began last fall, has been linked to a Mennonite wedding in New Brunswick and has since spread across the country, resulting in the largest measles outbreak in Canada in over a decade.

As of now, a total of 816 cases of measles have been reported in Ontario, with the majority of cases occurring in unvaccinated children. The region around St. Thomas and Elgin County has seen the highest number of infections, with 32 new cases reported in the past week. Chatham-Kent has also experienced a spike, with 47 new cases recorded recently.

The breakdown of cases by health unit from October 28, 2024, to April 9 is as follows:

– Southwestern Public Health: 238 cases (40.2%)
– Grand Erie Public Health: 127 cases (15.6%)
– Huron Perth Public Health: 94 cases (11.5%)
– Chatham-Kent Public Health: 90 cases (11%)
– South East Health: 58 cases (7.1%)
– Windsor-Essex County Health: 44 cases (5.4%)
– Region of Waterloo Public Health: 14 cases (1.7%)
– Middlesex-London Health Unit: 12 cases (1.5%)
– North Bay Parry Sound District: 11 cases (1.3%)
– Grey Bruce Health Unit: 10 cases (1.2%)
– Niagara Region Public Health: 10 cases (1.2%)
– Wellington-Dufferin-Guelph: 9 cases (1.1%)
– Lambton Public Health: 6 cases (0.7%)
– Northeastern Public Health: 2 cases (0.2%)
– City of Hamilton Public Health Services: 1 case (0.1%)

So far, 61 individuals have been hospitalized for measles treatment, with three requiring intensive care. Fortunately, no deaths have been reported.

Health officials are urging vaccination as a crucial measure to prevent the spread of measles. According to PHO’s report, 87.4% of cases are in unvaccinated individuals, while 9.7% are in individuals with no proof of immunization or unknown immunization status.

Dr. Ninh Tran, medical officer of health for Southwestern Public Health, emphasized the importance of vaccination during a media briefing, especially for parents and guardians of school-aged children. He highlighted the need for awareness in case of exposure to measles in school or childcare settings.

A memo from Ontario’s chief medical officer of health, Dr. Kieran Moore, confirmed that the current outbreak originated from a large gathering with guests from Mennonite communities in New Brunswick last fall. The Ontario Immunization Advisory Committee is advocating for a digital registry to streamline the tracking of vaccinations, which would benefit parents, healthcare providers, and public health officials in responding to outbreaks effectively.

As the measles outbreak continues to spread, it is essential for the public to stay informed and take necessary precautions to prevent further transmission of the virus.