TORONTO — Public health officials reported another 10 cases of measles in Ontario linked to an exposure in New Brunswick, bringing the number of patients affected by the outbreak to 37 as of mid-December.
In an epidemiological summary released last week, the public health agency said the outbreak began in October after someone was exposed to the highly contagious virus in New Brunswick. So far, 28 of those sickened were children or teens.
"Among the cases that have occurred since October, all but two cases were unimmunized," Dr. Christine Navarro, a physician with Public Health Ontario, said in an interview Monday.
"They're not all occurring among young infants, and that's what we would typically see: young infants who haven't received one (vaccine) dose or both doses in childhood yet."
Navarro said the number of cases has ballooned this year – up to 63 as of Dec. 18, compared to just seven cases last year. Symptoms of the virus include fever, a red blotchy rash, red watery eyes, and cough.
In May, the province reported its first measles-related death in years: an unvaccinated child under the age of five.
Navarro said the proportion of seven-year-olds who have had both doses of a measles-containing vaccine has dropped significantly over the years.
This year, school boards reported 70.4 per cent of students that age have had both doses, compared to 86 per cent in the 2019-2020 school year.
There are likely multiple reasons for the drop, Navarro said, including missed doses during the pandemic years, delayed reporting of vaccination rates to local public health units and vaccine hesitancy.
But she said boosting the vaccination rate is the best way to prevent such high numbers and serious consequences.
Public Health Ontario says there were 101 confirmed cases of measles in the province between 2013 and 2023, and never more than 22 cases in a year.
This report by The Canadian Press was first published Dec. 23, 2024.
Nicole Thompson, The Canadian Press
