Molecular Test Differentiates Influenza A Subtypes

A multiplex, real-time polymerase chain reaction (RT-PCR) in vitro diagnostic test detects influenza A from nasopharyngeal swabs.

The molecular diagnostic test simultaneously detects and differentiates three common influenza A virus subtypes: seasonal A/H1, seasonal A/H3, and the 2009 H1N1. It uses the same internal control and format as other tests for respiratory infectious diseases, and easily integrates into a laboratory's existing workflow.

The tests, called the ProFAST assay, has been optimized for use with automated extraction technology that minimizes technician hands-on time. Test results can be obtained in as little as four hours using this assay, a significant improvement over culture-based methods that can take days to produce a result.

The assay is a Prodesse product marketed by Gen-Probe Inc., (San Diego, CA, USA). The ProFAST assay has been cleared by U.S. Food and Drug Administration (FDA; Silver Springs, MD, USA) as the molecular diagnostic test to simultaneously detect and differentiate three common influenza A virus subtypes. The test complements the Prodesse ProFlu assay, which was cleared by the FDA in 2008 to detect and differentiate influenza A, influenza B, and respiratory syncytial virus (RSV). The ProFlu assay identifies samples containing 2009 H1N1 as influenza A, but unlike the ProFAST test, it does not differentiate among the various influenza A subtypes.


Carl W. Hull, M.B.A.., president and CEO of Gen-Probe, said, "FDA clearance of our ProFAST assay is important for public health, as the test enables physicians to accurately differentiate among influenza A subtypes that have different antiviral susceptibilities." Accurately differentiating among the three influenza A subtypes is important because each subtype has a different susceptibility to commonly used influenza antiviral drugs. For example, seasonal H1N1 has become resistant to the antiviral drug oseltamivir, whereas most cases of 2009 H1N1 and seasonal H3N2 respond to oseltamivir. Since August 2009, there were 66,873 cases of influenza due to H1N1 in the U.S. with 276 pediatric deaths.

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Gen-Probe Inc.
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