Diagnosis of pertussis
Pertussis (whooping cough) is caused by Bordetella pertussis. It classically presents with a persistent cough (lasting longer than 2 weeks) with one or more of the following features:
- paroxysms of coughing
- inspiratory whoop
- post-tussive vomiting.
Children 12 months or younger have the highest risk of morbidity and mortality from pertussis; the clinical signs of serious infection are usually nonspecific, although apnoea is often presentCDC, 2022. Older children and adults may not have the classical symptoms of pertussis and may present with only a persistent cough.
Pertussis infection is most commonly diagnosed by nucleic acid amplification testing (NAAT) (eg polymerase chain reaction [PCR]). For both children and adults, the optimal diagnostic sample for NAAT is a posterior nasopharyngeal swab1 or nasopharyngeal aspirate – a throat or anterior nasal swab is less sensitive for the diagnosis of pertussis. NAAT is most sensitive in the first 3 to 4 weeks following cough onsetCDC, 2022(ECDC), 2022.
Culture of nasopharyngeal swabs is used for epidemiological purposes – refer to a local microbiology laboratoryCDC, 2022.
Report cases of pertussis to the local public health authority; see the Pertussis (whooping cough) – Communicable Diseases Network Australia (CDNA) National Guidelines for Public Health Units and Contact details for health departments and public health units.