Whooping cough cases are on the rise in Canada, with some provinces reporting sharp increases compared to pre-pandemic averages.
More than 11,670 cases have been reported in Quebec so far this year, which represents a significant increase compared to the annual average of 562 cases between 2015 and 2019. In June alone, there were 3,362 in the territory, according to data that The Duty obtained from the Ministry of Health and Social Services. The National Director of Public Health, Dr.r Luc Boileau, in July, described the situation as “rare” and “to be taken seriously”.
The majority of patients with whooping cough are between 10 and 14 years old, a spokesperson for the Quebec Ministry of Health said in an email to The Canadian Press.
The last peak of whooping cough activity in the province was in 2019, when 1,269 cases were reported, the government reports.
In June, Ontario recorded 470 cases of whooping cough, compared with a five-year average of 98, according to a provincial dashboard. Toronto has reported 99 cases so far this year, while Ottawa has recorded 76, more than double the pre-pandemic annual averages in those cities.
The numbers follow a whooping cough outbreak declared last week in New Brunswick, where 141 cases have been reported so far, exceeding the five-year average of 34 cases per year.
Preventable and potentially serious
Whooping cough, a highly contagious and vaccine-preventable disease, is on the rise across Canada, Dr.D Theresa Tam, Chief Administrative Officer of the Public Health Agency of Canada.
The disease can be very serious and even fatal, especially for very young children, Dr.D Tam during an interview last Friday.
“We call it the 100-day cough,” she said. “It can cause a significant cough for a very long period of time.”
Whooping cough is a cyclical disease that increases every two to five or six years, according to public health officials.
“It looks like we’re in one of those cyclical increases right now,” D.D Allison Chris, associate medical officer of health at Toronto Public Health.
It is a persistent cough that begins with cold-like symptoms and progresses over several weeks to include coughing fits that often end with a characteristic sound when an infected person catches a breath.
New Brunswick’s acting chief medical officer of health says the province has not had a whooping cough outbreak in more than 10 years.
“I guess you could say we were definitely overdue for a surge in cases,” Dr.r Yves Léger in an interview on Tuesday.
He expects the current number of cases to increase before decreasing, given increased public awareness of the provincial outbreak.
Vaccines that protect children against whooping cough are part of Canada’s routine immunization program, which begins at two months of age. Primary vaccination requires four doses, followed by boosters later in childhood and adolescence.
A dose of acellular pertussis vaccine is also recommended for adults and during pregnancy.
The DD Chris said setbacks in routine vaccination coverage since the COVID-19 pandemic could indicate waning immunity to whooping cough.
COVID vaccine hesitancy seen during the pandemic may also have affected routine vaccination, Dr.D Anna Banerji, a pediatric infectious disease specialist in Toronto, in an interview.
Another challenge is that “even in fully vaccinated people, after a certain period of time, immunity can wane,” explained Dr.D Banerji in interview on Tuesday.
An increase in whooping cough cases has also been observed in the United States and elsewhere, prompting the Pan American Health Organization to issue an alert in July encouraging countries to strengthen surveillance and vaccination coverage.
With The Duty and information from Nicole Ireland (The Canadian Press), in Toronto