What should you know about the pertussis test name?

A clinician may call the test a pertussis PCR, a nasopharyngeal swab, or a culture. PCR detects bacterial genetic material and can provide an answer faster than culture, while culture attempts to grow the organism from a carefully collected sample. The choice depends on how long the cough has been present, the person’s age, prior antibiotics, and the laboratory available.

A positive result supports a diagnosis of whooping cough. A negative result does not always exclude it, especially when testing is late or treatment has already started. A [Cough](/symptoms/cough/) and [Fever](/symptoms/fever/) can also occur with many other illnesses.

Contact a clinician if a cough is severe, comes in repeated bouts, causes vomiting, or follows close contact with someone diagnosed with pertussis. The sample is often taken from deep in the nose with a flexible swab; it may feel uncomfortable and briefly make your eyes water. Follow instructions about medicines and attend promptly because early assessment can guide treatment and advice for close contacts. Do not share antibiotics or use leftover medicine; [Antibiotic Treatment](/treatments/medical-management/antibiotic-treatment/) needs clinical guidance.

Get urgent help for breathing difficulty, pauses in breathing, blue or grey lips, confusion, fainting, dehydration, or inability to keep fluids down. Babies may have breathing pauses or poor feeding without a classic whoop. A test should not delay emergency care when breathing is affected. Ask about avoiding contact with newborns and other vulnerable people while an infectious cough is being assessed.

Which test are you ordering and why? Where will the sample be collected? When should I expect the result? Should household members be assessed or treated? Does my vaccination history change how you interpret the result?