Differential Test for Flu A and B

A rapid in vitro assay for the direct and qualitative detection of influenza A and B viral antigens has the ability to distinguish the viral antigens of influenza A from those of influenza B, allowing for timely and proper treatment.

The assay was developed by Becton, Dickinson and Company (Sparks, MD, USA). The company says it is an important advance in therapeutic decision-making for several reasons. One is that some antiviral therapies are effective only for influenza A, while others may be used to treat both strains. Thus, the assay can help clarify which treatment should be given. Second, antiviral agents must be given within the first 48 hours of illness to be effective. A test that provides results in 15 minutes promotes such treatment.

The test is an enzyme immunoassay membrane test that can be used with a variety of specimens, such as nasopharyngeal wash, nasopharyngeal aspirate, lower nasal swab, or throat swab. Easy-to-read results are determined by visual color development in the ColorPAC wells of the test device. The development of a purple triangle on the membrane in either the A or B well indicates a positive test. The test is called the BD Directigen Flu A+B.