Whooping cough is being reported in higher-than-usual numbers in parts of Canada this year, health officials tell CTVNews.ca.

Cases of whooping cough – also known as pertussis or the 100-day cough – are increasing in several provinces and territories, a spokesperson for Health Canada and the Public Health Agency of Canada said in an email Friday.

Health Canada describes the illness as a contagious lung and airway infection. It’s caused by the bordetella pertussis bacteria, which is spread through droplets in the air when an infected person coughs or sneezes.

Joshua Coke said some increased activity was not unexpected post-pandemic, as case numbers reached record lows between 2020 and 2022. But, he said, cases in five provinces have now surpassed the pre-pandemic peak.

The provinces seeing more cases this year than they have in the past are Ontario, Quebec, New Brunswick, Prince Edward Island and Newfoundland and Labrador.

Canadian health officials have reported 19,000 cases of pertussis so far this year, Coke said. In addition to the provinces seeing a higher-than-usual number of cases, outbreaks or increases have been noted in Alberta, British Columbia and Nunavut.

According to a Health Canada’s website last updated in January 2020, the country typically sees 1,000 to 3,000 cases a year.

Is whooping cough still around in Canada?

One of the most popular pertussis-related queries Canadians type into search engines is whether the illness is still around in Canada.

While cases are still reported each year, whooping cough was mentioned by the country’s top doctor in a year-end interview with The Canadian Press on her biggest health concerns heading into 2025. 

“There’s an increase in circulation of a number of vaccine-preventable diseases like measles, like pertussis,” Dr. Theresa Tam said.

Whooping cough was controlled by vaccination for years, she said, adding that one of the reasons it may be coming back is the pandemic’s disruption on routine childhood vaccinations.

“We’re still not back at the pre-pandemic levels of vaccine coverage,” she told CP.

What are the symptoms of whooping cough?

As the name suggests, coughing is the most recognizable symptom of whooping cough. Health Canada says it can cause “serious coughing fits that can lead to choking or vomiting.

“The coughing can be so intense that a ‘whooping’ sound happens when you try to catch your breath.”

Listen to the sound of this distinct cough here.

While initially it presents as a cold, with a runny nose, fever and mild cough, anyone with a severe or prolonged cough should see a doctor to be diagnosed, Health Canada says. 

Additional symptoms include runny nose, sneezing, low-grade fever, and can include difficulty breathing and feeding poorly, particularly in infants.

Complications include weight loss and pneumonia, and health officials say rib fractures, rectal prolapse, urinary incontinence, convulsions and brain damage are possible.

Typically, infants are at the highest risk of severe symptoms, while teens and adults may see something milder, or can even be asymptomatic. Still, even mild and asymptomatic cases are a source of infection, health officials warn, especially in the first two weeks after coughing starts.

Will whooping cough go away by itself?

Health Canada warns that pertussis can last for weeks or months if untreated, and in some cases it can cause brain damage or death. 

Doctors say it’s especially dangerous for infants.

Whooping cough treatment

Whooping cough is diagnosed by doctors with a combination of laboratory test results and a patient’s symptoms.

It’s typically treated with antibiotics. Those who have been diagnosed are advised to avoid children until they’ve had at least five days’ worth of antibiotics, Health Canada says.

Those who don’t get treatment are told by public health officials to avoid contact with everyone, and stay isolated for three weeks after the cough starts, or until their cough ends.

How whooping cough outbreaks are monitored

Whooping cough is considered a “nationally notifiable disease” in Canada, meaning it’s an illness that PHAC tracks country-wide, with reports from provincial and territorial health officials. It’s monitored through the Canadian Notifiable Disease Surveillance System, which has been set up to keep track of transmission of infectious diseases.

This system was created for the monitoring and control of specific diseases deemed a priority, such as leprosy, cholera, measles, anthrax, chickenpox and meningitis. It’s been around since the 1920s.

This is a developing news story and will be updated.