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.
Whooping Cough Symptoms
Symptoms will start to appear from 1 to 3 weeks after exposure to the bacteria.[2]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), seizures, hypoxic encephalopathy (lack of oxygen to the brain) and death.[3]
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.[2]It is highly infectious in unvaccinated people, and can infect 90% of susceptible household contacts.[3]
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
Dehydration from poor feeding
Middle-ear infections
Apnoea
Pneumonia
Inflammation of the brain
Convulsions
Permanent brain damage
Death[4]
Whooping Cough Prevention
Vaccination is the only form of prevention against whooping cough. Children are eligible for pertussis vaccination under the National Immunisation Program.
In Australia, it is recommended that children receive a 5-dose schedule of pertussis vaccine.
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.[5] In these cases, antibiotics are usually not needed.
More Whooping Cough Information
Infants less than 6 months are at greatest risk of severe disease and death.[2]
If a child under 6 months of age gets whooping cough, they will usually need to be admitted to hospital.[6]
Household contacts and carers are often the source of infection in infants. Parents are the source in more than 50% of cases.[7] Vaccination of both parents is estimated to reduce the risk of infant pertussis by 51%.[8]
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Centers for Disease Control and Prevention. Pertussis (Whooping Cough): About Whooping Cough. Atlanta, GA: CDC; [updated 2023 May 16; cited 2024 Oct 31]. Available from: https://www.cdc.gov/pertussis/about/index.html
