Pertussis (also known as whooping cough) is a disease that is caused by the bacteria Bordetella pertussis. It causes a very serious infection of the lungs and breathing airways. Whooping cough is known for uncontrollable, violent coughing fits that often makes it hard for people to breathe. After coughing over and over, someone with whooping cough often needs to take a deep breath, which causes a “whooping” sound.

Whooping cough can affect people of all ages, but it can be very serious, and even deadly, in babies who are less than 1 year old, especially if they have not been vaccinated or if they are under-vaccinated. The best way to protect yourself and those most vulnerable to whooping cough is vaccination.

How pertussis is spread

Whooping cough is very contagious. It spreads through droplets in the air when an infected person coughs or sneezes. People can catch it by sharing breathing space with an infected person or touching an infected surface and then touching their eyes or mouth. The bacteria can live for 2 to 5 days on dry objects such as clothing, glass or paper. A person can spread the disease from the beginning of the sickness and for at least 2 weeks after the coughing begins.

Risks of pertussis

Whooping cough is dangerous for babies and young children. In fact, 20% to 30% of babies less than 1 year old get so sick they have to be hospitalized; 1 in 400 will get brain damage. Complications in babies include vomiting after coughing, weight loss, pneumonia (an infection in the lungs), seizures and brain damage.

Whooping cough is still a common disease. In Canada, 1,000 to 3,000 people each year get whooping cough. Around the world, there are about 20 to 40 million cases each year, and 400,000 people die from it. A person with whooping cough will infect almost everyone in their household if those people are not protected by vaccination.


Early stage: Symptoms are usually mild at first and are like the symptoms of a common cold, including a runny nose, a minor fever and mild coughing. Sometimes, very young infants do not cough at all. Instead, they may have pauses in their breathing (this is called “apnea”). Because whooping cough in its early stages appears to be nothing more than a cold, it is often diagnosed only after the symptoms get worse.

Later stage: After 1 to 2 weeks, thick mucus begins to accumulate inside the airways, which causes severe coughing fits. Coughing over and over can cause babies and children to:

  • gasp for breath (with a “whooping” sound) or gag
  • have difficulty breathing, eating or sleeping
  • turn blue from lack of oxygen
  • vomit

Teens and adults may cough so hard that they pass out or break a rib. Because whooping cough can last for 10 weeks or even longer, it is often called the “100-day cough”.

Protection and prevention

You can protect yourself and your children against whooping cough with a safe and effective vaccine. For the best and continuing protection, multiple doses are recommended throughout your lifetime. The vaccine is given at:

  • 2 months, 4 months, 6 months, and 18 months of age
  • 4 to 6 years of age
  • 14 to 16 years of age
  • in adulthood
  • in each pregnancy, ideally between 27 to 32 weeks of gestation

Parents, grandparents, other family members and caregivers of infants and young children should get vaccinated if they are not up to date with their whooping cough vaccinations.

To protect newborn babies from getting whooping cough, pregnant individuals should get a vaccination in the third trimester. A dose is recommended for each pregnancy regardless of any previous doses received. The vaccines are part of the publicly funded vaccines and are offered free to all people in Ontario. The whooping cough vaccine is required for children to attend school in Ontario and for children attending a daycare centre unless they have a valid exemption.

No vaccine is 100% effective, so even people who have had the vaccine can sometimes get this very contagious disease. However, those who have been vaccinated and still get whooping cough may have a much milder case. If you or your child gets a cold that includes a very bad cough, or a cough that lasts a long time, contact your health care provider.

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