Respiratory test identifies 12 viruses at once

The US Food and Drug Administration has authorised the marketing of a test that simultaneously detects and identifies 12 specific respiratory viruses from a single throat swab.

The test, called the xTAG Respiratory Viral Panel, is the first test for the detection and differentiation of influenza A subtypes H1 and H3. Influenza A is the most severe form of influenza for humans and has been the cause of major epidemics.

The panel is also the first test for human metapneumovirus (hMPV), newly identified in 2001.

The panel amplifies viral genetic material found in secretions taken from the back of the throat in patients with possible respiratory tract infections. The test binds specific beads (or microspheres) to the amplified viral genetic material, which are then sorted to identify the specific viruses.

The xTAG panel is the first FDA-cleared test for infectious respiratory disease viruses that uses a multiplex platform, allowing several tests to be processed using the same sample.

“Nucleic acid tests, such as the xTAG Respiratory Viral Panel, utilise small amounts of genetic material and then replicate it many times,” said Daniel Schultz, director of FDA’s Center for Devices and Radiological Health.

“This speeds up the usual process of detecting and identifying respiratory viruses, which can take up to a week,” said Schultz. “And, because this multiplex viral panel tests for 12 viruses at once, it uses less of a patient’s test specimen.”

Other viruses identified by the xTAG Respiratory Viral Panel include: influenza B; respiratory syncytial virus subtype A and B (leading causes of infant pneumonia and bronchiolitis); parainfluenza 1, 2 and 3 (the croup and the common cold); rhinovirus (the most widespread cause of the common cold); and adenovirus (similar to tonsillitis).

While the test is faster than conventional tests, it is specific only to the dozen viruses listed and should be used in correlation with other diagnostics, such as patient data, bacterial or viral cultures and X-rays.