Whooping Cough

Whooping cough (pertussis) is a highly contagious respiratory infection that can be mild in adults, but is life-threatening for young infants.

Immunisation Coalition

About Whooping Cough

Whooping cough (or pertussis) is a highly contagious respiratory infection caused by the bacteria ‘bordetella pertussis‘. These bacteria attach to the cilia (tiny, hair-like extensions) that line part of the upper respiratory system. The bacteria release toxins (poisons), which damage the cilia and cause airways to swell.[1]

Although the infection is mild in adults, if passed on to vulnerable babies it can be life-threatening.


1 Centres for Disease Control and Prevention (CDC) Pertussis Causes and Transmission (last reviewed 7 August, 2017)

Whooping Cough Symptoms

Symptoms will start to appear from 1 to 3 weeks after exposure to the bacteria. The disease begins like a cold with a runny nose, mild fever and a cough. The cough gets worse and can last 1-2 months or longer.[2] A thick, sticky mucus develops in the windpipe, which makes it difficult to eat, drink and breathe. In babies, this results in coughing fits often accompanied by a ‘whoop’ as it struggles to catch its breath. Older children and adults may just have a dry, persistent cough often without the ‘whoop’, so many cases are often mistaken for a bad chest cold or bronchitis.

Although cases in adults are considered mild, they are still highly contagious and can easily be unknowingly passed on to others. Some children cough so much they vomit afterwards.

The coughing fits can go on for up to 10 weeks or more. The infection is generally milder in teens and adults, especially those who have been vaccinated.

Severe complications, which occur almost exclusively in unvaccinated people, include pneumonia (lung infection), hypoxic encephalopathy (lack of oxygen to the brain) and death.[3]



2 Pertussis vaccines for Australians/NCIRS Fact sheet: March 2016.

3 Australian Technical Advisory Group on Immunisation (ATAGI). Australian Immunisation Handbook, Australian Government Department of Health, Canberra, 2018.

How Whooping Cough Spreads

Pertussis is highly contagious and only found in humans. It is easily spread from person-to-person via droplets from close contact i.e. when you talk, sneeze, cough or kiss. Many babies who get pertussis are infected by older siblings, parents, or caregivers who might not even know they have the disease.[1] People with pertussis are most infectious in the first three weeks after the onset of symptoms. If you catch it, there is an 80% chance that other members of your household will catch it too.

Whooping Cough Complications

Severe complications which occur almost exclusively in unvaccinated people, include pneumonia, hypoxic encephalopathy and death.

Complications of whooping cough in young babies include:

  • haemorrhage
  • apnoea
  • pneumonia
  • inflammation of the brain
  • convulsions
  • permanent brain damage
  • death[4]

4 Better Health Channel Whooping Cough (last updated October 2019)

Whooping Cough Prevention

Vaccination is the only form of prevention.  Children are eligible for Pertussis vaccination under the National Immunisation Program. See your GP to find out more.

Whooping Cough Treatment

Antibiotics may be given to prevent the spread of pertussis to other people. If the patient has been coughing for more than three weeks, they are no longer infectious. In these cases, antibiotics are usually not needed.

More Whooping Cough Information

Children under one year of age have a 50% hospitalisation rate 0.5% mortality.

Infants less than 6 months are at greatest risk of severe disease and death.

If a child under 6 months of age gets whooping cough, they will usually need to be admitted to hospital.[5]



5 Royal Children’s Hospital (RCH) Kid’s info Whooping cough Fact Sheet (last reviewed April 2019)


Page Published: 8 March 2017 | Page Updated: 5 August 2020