Pertussis (Whooping Cough)

Pertussis, also known as Whooping Cough, is a vaccine-preventable disease that infects about 1,000 to 3,000 Canadians annually. Pertussis is highly contagious and potentially fatal, with about one to three deaths attributed to the disease each year in Canada.

Babies, particularly infants under two months old who are not yet eligible for vaccination, and pregnant individuals, especially those in the last three months of pregnancy, are most at risk of developing severe complications from pertussis.

Vaccination is the best defence against pertussis.


What is Pertussis?

Pertussis is an infection of the lungs and airways, caused by a bacteria called Bordetella Pertussis.

Pertussis is easily spread through respiratory droplets in the air from the coughs and sneezes of an infected person. Indirect spread through contaminated objects and surfaces rarely occurs, if at all. The disease is most contagious during the first two weeks after coughing starts. People are no longer contagious after five days of appropriate antibiotic treatment.


What are the symptoms of Pertussis?

In its initial stages, pertussis can often be mistaken for the common cold.

Stage 1 symptoms may begin five to 10 days after infection, but symptom onset can take longer – sometimes up to 28 days from contact with the bacteria that causes pertussis.


Stage 1 (Catarrhal) symptoms can include:

  • Runny or stuffed-up nose;
  • Low-grade fever;
  • Red, watery eyes; and
  • A mild, occasional cough.

For infants, symptoms include a severe cough (some infants do not cough), choking after coughing, feeding poorly, and difficulty breathing.


Stage 2 (Paroxysmal) symptoms, which usually begin one to two weeks after first symptom onset, can include rapid, violent coughing fits, which usually last one to six weeks but can persist for up to 10 weeks. The coughing fits can cause people to make a high-pitched “whoop” sound when they inhale after coughing. This sound is why pertussis is often called whopping cough.


Infants with pertussis may develop complications, such as vomiting after coughing, weight loss, pneumonia, convulsions, and even brain damage. Babies with whooping cough may have spells where they don’t breathe or have seizures. In serious cases, they can go into a coma.


Stage 3 (Convalescent) Symptoms

  • Gradual recovery over weeks to months
  • Infants may present with atypical symptoms (apnea, seizures, sneezing, gagging, choking, vomiting)
  • Complications include pneumonia, atelectasis, seizures, encephalopathy, weight loss, hernias, and death


How can pertussis infections be prevented?

The best way to protect against pertussis is to stay up-to-date on the pertussis vaccine.

In Ontario, a combination vaccine that protects against pertussis is given to people at:

  • Two months, four months, six months, and 18 months of age;
  • Four to six years of age;
  • 14 to 16 years of age; and
  • In adulthood.

These vaccines are covered by the Province of Ontario and included in the Publicly Funded Immunization Schedules for Ontario.



In April 2022, the Province expanded Ontario’s publicly funded immunization program to make pregnant individuals eligible to receive one dose of the tetanus, diphtheria, acellular pertussis (Tdap) vaccine during each pregnancy.

This vaccine helps to protect the mother and her newborn from pertussis, as antibodies produced by the mother following vaccination are passed to the fetus before birth and protect the baby for the first few months of life.

The Tdap vaccine should be routinely offered to all pregnant individuals in every pregnancy between 27 to 32 weeks, irrespective of immunization history.


If I’ve had pertussis in the past, do I have natural immunity to the infection?

People who have had whooping cough have some natural immunity (protection) against future whooping cough infections. However, this natural immunity doesn’t provide lifelong protection. Therefore, vaccination is still recommended.


How is pertussis treated?

Pertussis is usually treated with antibiotics. Those infected with pertussis should stay away from children and infants until they take at least five days' worth of antibiotics.

If the person is not getting treatment, they should avoid contact with others and stay isolated for three weeks after the cough began, or until the cough ends, whichever comes first.


When should I seek medical help for my child?

If you suspect your child has pertussis, take them to see a Primary Care Provider even if they have been vaccinated against the infection.

Your child should see a doctor if they have coughing that:

  • is followed by vomiting;
  • is followed by a whooping sound when they breathe in after coughing;
  • causes breathing problems; or
  • makes their skin or lips turn red, purple, or blue.


Where can I find additional information about pertussis?


Share this page