Rapid Influenza Test
A rapid influenza test is a diagnostic test that can detect the presence of influenza A and B viral nucleoprotein antigens in respiratory specimens. The swab is collected from the nasal passage/ nasopharyngeal passage. The processing requires about 15 minutes.
While many practitioners and patients feel that rapid influenza tests are unreliable, its important to know that the window for accuracy in testing is within the first three to four (3-4) days of the onset of symptoms. Just because the result is negative also doesn’t mean you don’t have influenza – you just may not have influenza A or B. Accuracy of flu tests range from 50%-90% depending on the test, the collection, the timing, the patient and the prevalence of flu in the community.
A new type of flu test available in many clinics is the rapid molecular assay or molecular flu test. Collected in much the same manner as the rapid flu test, the main different is the processing time ranges from 15-30 minutes and the reliability of the result. The most accurate type of flu test remains a viral culture test which can determine the strain of virus, but this requires the specimen being sent to a more complex lab for processing.