Whooping cough is an upper respiratory tract infection caused by Bordetella pertussis (a gram negative bacteria). It is called “whooping cough”, because the coughing fits are so severe that the child is unable to take in any air between coughs and subsequently makes a loud whooping sound as they forcefully suck in air after the coughing finishes.
Children and pregnant women are vaccinated against pertussis. The vaccine becomes less effective a few years after each dose.
Presentation
Pertussis typically starts with mild coryzal symptoms, a low grade fever and possibly a mild dry cough.
More severe coughing fits start after a week or more. These involve sudden and recurring attacks of coughing with cough free periods in between. This is described as a paroxysmal cough. Coughing fits are severe and keep building until the patient is completely out of breath. Patient typically produces a large, loud inspiratory whoop when the coughing ends. Patients can cough so hard they faint, vomit or even develop a pneumothorax. Bear in the mind that not all patients will “whoop” and infants with pertussis may present with apnoeas rather than a cough.
Diagnosis
A nasopharyngeal or nasal swab with PCR testing or bacterial culture can confirm the diagnosis within 2 to 3 weeks of the onset of symptoms.
Where the cough has been present for more than 2 weeks patients can be tested for the anti-pertussis toxin immunoglobulin G. This is tested for in the oral fluid of children aged 5 to 16 and in the blood of those aged over 17.
Management
Pertussis is a notifiable disease. Therefore Public Health need to be notified of each case.
Management typically involves simple supportive care. Vulnerable or acutely unwell patients, those under 6 months and patients with apnoeas, cyanosis or patients with severe coughing fits may need to be admitted. Measures to prevent spread are important, such as avoiding contact with vulnerable people, disposing of tissues and careful hand hygiene.
Macrolide antibiotics such as azithromycin, erythromycin and clarithromycin can be beneficial in the early stages (within the first 21 days) or vulnerable patients. Co-trimoxazole is an alternative to macrolides.
Close contacts with an infected patient are given prophylactic antibiotics if they are in a vulnerable group, for example pregnant women, unvaccinated infants or healthcare workers that have contact with children or pregnant women.
The symptoms typically resolve within 8 weeks, however they can last several months. It is also known as the “100-day cough” due to the potential long duration of the cough. A key complication of whooping cough is bronchiectasis.
Last updated August 2019