What should you know about an express PCR test?

PCR testing usually uses a swab from the nose or throat to collect a sample. In the laboratory, molecular methods look for genetic material from the virus being tested. Express processing changes how quickly the result is reported; it does not make a positive result mean that symptoms will be severe.

A negative result lowers the likelihood that the target virus was detected in that sample, but timing, collection quality and the infection stage can affect interpretation. A result should be read with your symptoms, exposure history and the test provider's instructions.

Follow the provider's instructions about arrival, identification, sample collection and result delivery. Until you know what applies to you, reduce close contact when you have respiratory symptoms, improve ventilation and wear a well-fitting mask around vulnerable people.

If the result is positive, follow current clinical advice about staying home, notifying close contacts when appropriate and seeking treatment. A rapid antigen test kit may provide a quicker preliminary result, while a clinician may recommend PCR testing when a more sensitive laboratory method is needed.

Seek emergency care for severe breathing difficulty, chest pressure, new confusion, blue or grey lips, collapse or inability to stay awake. Contact a clinician promptly after a positive result if you are pregnant, immunocompromised, have significant long-term conditions or symptoms are worsening. Do not delay urgent help while waiting for a test result.

Ask what the test detects, when the sample should be collected, how the result will be delivered, whether a repeat or different test is needed, and what precautions apply while waiting. Mention symptoms, recent exposure and any condition that increases your risk of complications.