What you need to know about whooping cough in Ontario

Whooping cough cases are on the rise in parts of Ontario, and experts are urging parents to remain vigilant as the disease can be most dangerous for young children.

Earlier this week, the Haliburton-Kawartha-Pine Ridge District Health Unit issued a warning about increased whooping cough activity within school communities and urged parents to monitor their children for symptoms.

Ontario Public Health reports there have been at least 70 cases across the province so far this year. Cases have risen steadily over the past three years, with 16 cases reported in 2021, 159 in 2022 and 333 in 2023.

“Every year it seems like the cases are increasing. It's certainly increasing, but it's not just limited to Ontario,” Dr. Isaac Bogoch, an infectious disease specialist at the University of Toronto Health Network, told CTV News Toronto. “It's a terrible infection. It's already widespread and sadly has been increasing recently, but a lot of that can be mitigated with timely vaccination.”

Here's everything you need to know about whooping cough (also called pertussis).

What is whooping cough?

Whooping cough is a highly contagious infection caused by Bordetella pertussis, which affects the airways and lungs. It was once called “whooping cough” because symptoms can last for months if left untreated. Whooping cough caused thousands of deaths in the 1930s and 1940s. The introduction of a vaccine has significantly reduced the death rate.

What are the symptoms?

The disease is known to cause uncontrollable coughing fits accompanied by a characteristic whooshing sound when air is inhaled. The coughing associated with the disease is usually severe and rapid. Symptoms may include sneezing, runny nose, and watery eyes. As the coughing continues, the lips, tongue, and nail beds may turn blue.

“It's just an excruciatingly painful cough. The coughing sounds almost like a person is gasping for air and choking,” Dasantila Goremi Kotla, an associate professor of microbiology at York University, told CTV News Toronto on Thursday.

“That's the main symptom that distinguishes this type of respiratory disease from other respiratory diseases.”

Golemi-Kotla described the disease as “very visible.” The cough is very clearly identifiable, she said.

“Now that we're hearing that there are actually increasing cases, not just in Canada but all over the world, it's even more important to be more aware of the symptoms,” she said.

“If you have an infant who may be infected, take them to the doctor right away so they can be diagnosed as having whooping cough or another respiratory illness.”

How dangerous is it?

The disease is especially dangerous for babies under the age of one and pregnant women in the later stages of pregnancy. If you have been infected or are experiencing symptoms, it is best to contact your health care provider immediately for further testing.

“The coughing can get so bad that it can burst blood vessels in the eyes. There have been reports of people breaking ribs. It's nothing compared to the worst coughing. Some people cough so badly that they vomit,” Bogoch said.

“They will recover with medical care, but it's more dangerous for small children who have narrow tracheas.”

Infants under 1 year of age are at highest risk of severe illness and often require hospitalization, and almost all deaths from infection occur in infants under 6 months of age.

Bogoch said the cough can last for a long time, sometimes for weeks or even months.

“The cough can linger and become severe,” he says.

How to prevent it?

The most effective defense against whooping cough is vaccination. Although a vaccine has been developed against whooping cough, which often strikes infants as early as 2 months of age and often in their first year of life, cases of whooping cough still occur, especially in infants under 6 months of age.

Prophylactic antibiotics are used to prevent people who have been exposed to harmful bacteria from getting sick. People who have been near a person with whooping cough are recommended to receive antibiotics to prevent the disease.

Practicing good hygiene habits is also important to prevent the spread of bacteria and viruses that can cause many respiratory illnesses.

How many cases are there in Toronto?

As of Wednesday, Toronto Public Health had reported 38 whooping cough cases in the city so far this year, up from an average of 60 cases per year pre-pandemic (2015-2019).

Public Health is currently hosting community clinics to help students receive school-based vaccinations, including the whooping cough vaccine.