Eastern Ontario seeing surge of whooping cough cases

Health officials across Ontario are warning of a significant spike in cases of pertussis, also known as whooping cough.

Public Health Ontario says as of Sept. 9, 1,016 cases have been reported in the province. That’s the highest since 2012 when 1,044 cases were reported.

• Sign up now for daily CTV News Ottawa newsletters
• The information you need to know, sent directly to you: Download the CTV News App

The health unit says the majority of cases were among children between the age of 10-14, accounting for 37.8 cases per 100,000 people. From 2015-2019, that rate was 13.3.

On Sept. 11, the Children’s Hospital of Eastern Ontario (CHEO) said they had seen 90 cases of whooping cough so far this year, compared to just six in 2023. Ottawa Public Health told CTV News that as of Sept. 16, it has received reports of 126 people with confirmed or probable pertussis in Ottawa.

CHEO takes in patients from other regions, OPH said, so its figures could also include patients from other health units in eastern Ontario, western Quebec and Nunavut, an OPH spokesperson said.

The Leeds, Grenville & Lanark District Health Unit says it has seen 53 cases in 2024, with most coming from people under the age of 20.

"The strength of the cough, can be so bad as to, for example, cause broken bones, especially broken ribs. It can cause people to vomit after coughing. It can cause people to lose oxygen to the point because they're coughing so hard that their, skin can turn pale or even blue," said Dr. Linna Li, the Medical Officer of Health for the Leeds, Grenville and Lanark District Health Unit.

A vaccine for whooping cough exists and is part of Ontario students' regular immunization schedule, but Li said that the vaccine can wane over time.

"Vaccination for pertussis, the effectiveness of the vaccine does wane over time," she said. "It's not quite clear the length of protection at this point. But we do know that there's some waning over time."

The whooping cough vaccine is required for children attending school, and Ottawa Public Health recently said they would start issuing suspension notices in the new year for children who don’t have updated vaccination records.