Updated January 2018


Pertussis, or whooping cough, is a very contagious (easy to catch) disease of the respiratory tract. It is caused by a bacterium (germ) found in the mouth, nose and throat of the infected person.

Signs and Symptoms

Pertussis starts like a common cold, with sneezing, runny nose, low-grade fever and a mild cough. But over the next week or two, the cough gets worse and worse, leading to really bad coughing spells that often end with a whoop (which is where the name whooping cough came from). The coughing may be so bad that it makes a child gag or throw up. Sometimes a thick, clear mucous is spit out. This cough can last up to a month or two and happens more at night.


The germ is spread when a person with pertussis coughs or sneezes the germ into the air, where other people can breathe it in.

A person who is infected can give it to others in the early stages of illness, before the really bad coughing spells start. Older children and adults can give pertussis to young babies without knowing it. That is why older children and adults who have a cough for more than a week should get tested by their doctor to make sure they cannot give it to babies in the household. The test is done by a swab collected through the nose and sent to the lab for pertussis testing.

A person who has pertussis and does not get it treated can spread the germs to others for up to three weeks after the coughing spells start.


To test and diagnose pertussis, your health care provider can swab your throat or the back of your nasal passages through your nose.

Complications (that may arise)

Sometimes, but not often, pertussis can cause:

  • pneumonia: (one out of five cases);
  • convulsions or seizures: (one out of 30 cases);
  • encephalopathy (brain damage): (one out of 100 cases)
  • About one infant out of every 170 who gets pertussis will die from it. Most deaths (four out of five) are babies under a year old.

Risk Factors

Anyone can get pertussis, but it is most dangerous for children under a year old. Adults and older children that are around infants and young children should be vaccinated.

Since immunization programs begin at two months, infants under two months of age are very vulnerable. The children who are most at risk for pertussis are not vaccinated, or under-vaccinated.


A person with pertussis is usually given an antibiotic. Also, people who may have been in close contact with someone who has pertussis are also given medicine. This includes people living in the same house, and other household and day care contacts. The treatment usually takes 10 days.


Get vaccinated! Infants, teenagers and adults should be vaccinated against whooping cough.

The vaccine should be given to infants at two, four, six and 18 months of age, which is combined to protect against other childhood diseases such as diphtheria and tetanus. A booster dose should also be given when the child is between four and six years of age and another booster between 14 and 16 years of age. Adults should have one dose. The vaccine is publicly funded and available for free from your health care provider.


Call your doctor if you have symptoms of pertussis infection, or if you have been in contact with someone who has pertussis. Tell your doctor you think you may have pertussis before going to your doctor’s office. This will allow your doctor to prepare for your visit and protect other patients.

Persons diagnosed with pertussis or suspected of having pertussis should not attend child care, school or work, should not participate in group activities, should refrain from having visitors and avoid contact with young children, infants, and women in their third trimester of pregnancy until five days following the start of appropriate antibiotic treatment or 21 days after the start of symptoms.

Public Health Role

Toronto Public health works to prevent and reduce the spread of pertussis by promoting vaccination, conducting surveillance of cases and performing contact management.


Bordetella pertussis, the bacteria that causes whooping cough, is found in the respiratory secretions (fluids from the mouth and nose) of someone with whooping cough. The bacteria spread when respiratory secretions (fluids) that have the bacteria get into the mucous membranes (e.g., nose or mouth) of a person. This can happen when a person with whooping cough coughs or sneezes.

More information

For more information about the whooping cough (Pertussis) vaccine call the Toronto Public Health (TPH) Immunization Information Line: 416-392-1250.