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

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. 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.

How is it spread?

Pertussis is a 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. 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.

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.

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 information for Clinicians

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.

 

Complications

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

Some of complications of whooping cough in young babies:

• haemorrhage

• apnoea

• pneumonia

• inflammation of the brain

• convulsions

• permanent brain damage

• death

 

Epidemiology

Between 2008 and 2012, all Australian states experienced their largest pertussis epidemic. The highest rates of disease were in infants less than 6 months and children 5-9 years of age.

In 2016, 20,091 cases of pertussis were reported nationally.

In 2016, children under 15 years of age accounted for 52% of the pertussis notifications.

 

Vaccine efficacy

Outbreaks occur every 3-4 years but with reduced morbidity and mortality in vaccinated individuals.

A 3-dose primary series of immunisation with DTPa vaccine at 2, 4 and 6 months of age results in 84% protective efficacy against severe disease.

Immunity to pertussis wanes over time. Effectiveness of 3 doses of DTPa vaccine declined progressively from 2 years of age to less than 50% by 4 years of age.

A large trial in adolescents and adults demonstrated overall vaccine efficacy against confirmed pertussis of 92% within 2.5 years of vaccination.

 

Who should be vaccinated?

 

Infants and children

Free pertussis vaccine is available under the National Immunisation Program as follows:

Vaccine 2 mths[i] 4 mths 6 mths 18 mths 4 yrs 12-17 yrs
(DTPa)[ii] 1st dose 2nd dose 3rd dose 1st booster 2nd booster        N/A
(dTpa)[iii]       N/A       N/A       N/A       N/A       N/A 3rd booster

[i] First dose can be given as early as 6 weeks of age

[ii] DTPa = Diphtheria tetanus and acellular pertussis-containing vaccines, which are used in children < 10 years of age. There are seven formulations: Infanrix (DTPa), Infanrix hexa (DTPa-hepB-IPV-Hib), Hexaxim (DTPa-hepB IPV-Hib), Infanrix IPV (DTPa-IPV), Pediacel (DTPa-IPV-Hib), Quadracel (DTPa-IPV) and Tripacel (DTPa)

[iii] dTpa signifies formulations that contain substantially lesser amounts of diphtheria toxoid and pertussis antigens than child (DTPa-containing) formulations. dTpa vaccines are usually used in adolescents and adults. There are four formulations: Boostrix (dTpa), Boostrix-IPV (dTpa-IPV), Adacel (dTpa) and Adacel Polio (dTPa-IPV)

 

Adults

dTpa is recommended for any adult who wishes to reduce the likelihood of becoming ill with pertussis.

 

Special Risk Groups

Pregnant women (vaccine free under state and territory initiatives) and people in contact with infants (not funded under NIP for these individuals).

 

Click here to view or download the Pertussis GP Guide.

 

Page published:   8 March 2017

Page updated:     31 July 2017