What causes pertussis?

The bacteria attach to the lining of the airways and release substances that irritate the breathing passages. Early illness may resemble a mild cold, with a runny nose and a developing cough. The cough can then become severe, repetitive, and exhausting; some people make a whooping sound when breathing in, while babies may have pauses in breathing rather than a typical whoop. Vaccination reduces the risk of infection but protection can change over time, and previous infection does not always prevent another episode.

Contact a clinician promptly if a persistent or worsening cough follows cold-like symptoms, especially after contact with someone who has pertussis. Testing may involve a sample from the nose or throat. Antibiotic treatment may reduce spread and is most useful when started early, while cough relief and monitoring support recovery. Keep babies and other vulnerable people away from suspected infection until a clinician explains when contact is safer. Check whether childhood immunisation or recommended boosters are up to date.

Get emergency help for blue or grey lips, pauses in breathing, severe breathing difficulty, fainting, or inability to keep fluids down. Arrange urgent assessment for a baby with coughing spells, a child who becomes exhausted during coughing, or an adult with chest pain or worsening breathlessness.

Ask whether testing is needed, when you may return to school or work, whether household contacts need advice, and whether your immunisation record shows protection gaps.