Whooping cough

Whooping cough is a highly infectious disease of the airways that most commonly occurs in children. Also known as pertussis, it is a bacterial infection typically spread by coughing and sneezing.

Symptoms are usually mild in adolescents and adults but in children less than one year of age can be particularly severe requiring hospital treatment. In rare cases, whooping cough can be fatal.

Outbreaks tend to occur every three to five years in New Zealand. During the most recent national outbreak, from August 2011 to December 2013, 11,000 cases of whooping cough were reported. Three young children died from the disease and hundreds were admitted to hospital for treatment.

The highest rates of disease occur in infants less than one year of age. Vaccination against whooping cough is part of New Zealand’s national immunisation schedule and plays an important role in reducing the spread of the disease.

Signs and symptoms

Whooping cough is normally characterised by severe coughing spasms followed by a gasp for breath that sounds like a “whoop”. However, in some cases this distinctive noise is not evident and symptoms may be similar to other coughs and colds.

Whooping cough causes the lining of the airways to become inflamed and damaged. This leads to an excess production of mucus, which in turn further irritates the respiratory tract and causes the high-pitched cough characteristic of the disease. Croup is another respiratory tract infection with a characteristic barking cough that affects young children.

The symptoms of whooping cough usually follow a cycle that lasts for a number of weeks. There are three distinct stages:

First stage (catarrhal stage): lasting 1-2 weeks:

• Loss of appetite

• Slight fever

• Watery, running nose and eyes

• Fatigue

• Sneezing

• Irritating cough (particularly at night).

Symptoms experienced during this stage often resemble those of a common cold or mild bronchitis.

Second stage (paroxysmal stage): Usually lasting 1–6 weeks, but can continue for up to 10 weeks:

• Severe coughing spasms

• A high-pitched "whooping" sound when inhaling after a coughing spasm (the “whoop” sound may not occur with young infants)

• Vomiting or turning blue due to severe coughing or choking on mucus.

The coughing spasms characteristic of this stage may be triggered by such things as crying, feeding, overactivity, or tobacco smoke. Where possible, it is important to avoid exposure to potential triggers in order to reduce the frequency of coughing spasms.

Third stage (convalescent stage): may last for months:

• During this stage, symptoms subside, though subsequent respiratory infections, even months after the initial whooping cough infection, can cause a recurrence of the coughing spasms.

Spreading the disease

The whooping cough bacteria are spread from person to person in airborne droplets or by direct contact with infected throat or nasal discharges. Coughing and sneezing are the most common modes of transmission.

Once infection with the whooping cough bacteria has occurred, the time until symptoms appear is usually between five to 10 days, but can be up to 21 days.

The contagious period is from seven days following infection with the whooping cough bacteria, to up to one month after the appearance of the coughing spasms.

If there is an outbreak of whooping cough, it is advisable to keep uninfected children (especially those who are not immunised) away from possible sources of infection. Likewise, children with whooping cough should not go to school or day-care until they are no longer infectious.

Diagnosis

The disease can be difficult to diagnose in its early stages because of its resemblance to a common cold or bronchitis.

As the whooping cough bacteria can be detected in respiratory secretions, nose and throat swabs may be taken to confirm the diagnosis. A chest x-ray and blood tests may also be performed.

As whooping cough is a notifiable disease, the doctor who diagnoses it is required to notify a Medical Officer of Health.

Treatment

Because it is a bacterial infection, antibiotics are used in the treatment of whooping cough. They are most effective in reducing the severity of whooping cough when given in the very early stages of the disease.

Antibiotic treatment commenced once the disease is well established may be recommended to reduce the likelihood of the bacteria spreading but it may not reduce the severity of symptoms. Antibiotics may also be prescribed to treat other bacterial infections that may develop as a result of having whooping cough.

It may be recommended that family members of someone with whooping cough also take antibiotic treatment to prevent catching the disease and spreading it in the community.

Further treatment of whooping cough is supportive and involves making the child comfortable. This should include:

• Bed rest

• Small frequent meals

• Saline nose drops to remove thick mucus.

• Maintaining fluid intake to avoid dehydration (clear fluids are best).

Use of a humidifier to warm and moisten the air may be helpful in soothing the airways and reducing coughing spasms. Sitting with the child in a steamy bathroom can also be beneficial.

Cough suppressant medicines are not effective in treating whooping cough.

In particularly severe cases of whooping cough, treatment in hospital may be necessary. This is most commonly required in infants under six months of age, with approximately 75% of those affected in this age group requiring hospitalisation.

Treatment in hospital may include:

• Administering oxygen

• Suctioning secretions and mucus

• Administering fluids through a drip in the hand or arm in order to prevent dehydration

• Monitoring for signs of complications

• Isolation from other children to prevent the spread of the disease.

Complications

Complications of whooping cough can include:

• Dehydration

• Pneumonia

• Bronchiectasis

• Middle ear infection

• Temporary cessation of breathing (apnoea)

• Hernia (commonly in the groin) caused by excessive coughing

• Encephalopathy (disruption in brain function) eg: swelling, damage, seizures.

It is important to watch for any signs of complications. A doctor should be consulted immediately if complications are suspected.

Prevention, vaccination

To prevent the spread of the disease, immunisation is essential. Immunisation against whooping cough is given free to children as part of New Zealand’s national immunisation schedule. The whooping cough vaccine is given (in combination with vaccines against other diseases) at six weeks, three months and five months.

Children are not fully protected against whooping cough until they have had all three doses. As protection from the vaccine reduces over time, booster doses are given to children when they are four and 11 years old.

It is recommended that pregnant women get a booster dose of the whooping cough vaccine (which is free) from 16 weeks' gestation onwards. This is because the mother can pass her immunity on to the baby in her womb, which will help protect them from birth until they are old enough to be vaccinated themselves.

Further information and support

For further information about immunisations consult your GP or practice nurse, or contact:

Immunisation Advisory Centre

Freephone: 0800 IMMUNE (0800 46 68 63)

Website: www.immune.org.nz

For further information and support about whooping cough consult your GP or practice nurse, or contact:

Plunketline

Freephone: 0800 933 922 (operates 24 hours a day, 7 days a week)

Website: www.plunket.org.nz

Healthline

Freephone: 0800 611 116 (operates 24 hours a day, 7 days a week)

Website:www.healthline.govt.nz

References

Auckland Regional Public Health Service (2018). Whooping cough (Pertussis) [Web Page]. Auckland: Auckland Regional Public Health Service. http://www.arphs.health.nz/public-health-topics/disease-and-illness/whooping-cough-pertussis/ [Accessed: 18/02/20]
Auckland Regional Public Health Service (2018). Information for people with whooping cough (Pertussis) Fact Sheet (PDF). Auckland: Auckland Regional Public Health Service. http://www.arphs.health.nz/our-resources/fact-sheet-information-for-people-with-whooping-cough-pertussis/ Immunisation Advisory Centre (2019) Pertussis (Web Page). Auckland: Immunisation Advisory Centre (IMAC) University of Auckland. www.immune.org.nz/diseases/pertussis [Accessed: 18/02/20]
Ministry of Health (2019) Whooping Cough (Web Page). http://www.health.govt.nz/your-health/conditions-and-treatments/diseases-and-illnesses/whooping-cough [Accessed: 18/02/20]

 

Last reviewed - February 2020

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