The Food and Drug Administration (FDA) today cleared a new test developed by the U.S. Centers for Disease Control and Prevention (CDC) to diagnose human influenza infections and the highly pathogenic influenza A (H5N1) viruses.
The device, called the Human Influenza Virus Real-Time RT-PCR Detection and Characterization Panel (rRT-PCR Flu Panel), uses a molecular biology technique to detect flu virus and differentiate between seasonal and novel influenza.
The device is used to isolate and amplify viral genetic material present in secretions taken from a patient's nose or throat. The viral genetic material is labeled with fluorescent molecules, which are then detected and analyzed by a diagnostic instrument called the Applied Biosystems 7500 Fast Dx, also cleared today by the FDA for diagnostic use simultaneously with the CDC's rRT-PCR Flu Panel.
The test panel and diagnostic system can detect and identify commonly circulating human influenza viruses as well as influenza A (H5N1) viruses. Results can be available within four hours and the system can test multiple samples at once.
"This is a significant achievement for public health surveillance," HHS Secretary Mike Leavitt said. "The test allows us to better support laboratories on the front line of influenza testing in the United States and abroad."
"The application of the test to detect an emergent influenza virus would be especially important in the early stages of a pandemic," Secretary Leavitt added. "This breakthrough allows for a more timely detection of a pandemic virus, which helps in determining when to begin broad control strategies as well as life-saving mitigation measures, such as closing schools, cancelling social gatherings and informing businesses to begin work-at-home policies."
The test will be available to CDC-qualified laboratories for diagnosing influenza this fall, and some laboratories will be able to obtain reagents (certain substances used in the testing process) at no cost.
This test should help ensure the accuracy of influenza testing results among the different qualified laboratories that conduct influenza subtype testing.
"This new test provides us another tool in our toolbox to fight seasonal influenza, a virus that unfortunately kills thousands of people each year in the United States," said CDC director Julie Gerberding, MD, MPH. "We'll now be able to detect influenza in the community faster, which allows us to take steps more quickly to protect and save lives."
Since influenza viruses are always changing, test reagents need to be evaluated regularly against circulating viruses to ensure the sensitivity and specificity of the test to diagnose current influenza viruses.
"Because the test can tell the difference between seasonal human influenza viruses and novel viruses, it will also provide qualified laboratories with a means to rapidly detect new influenza viruses that have not been identified yet and that could pose a pandemic risk," said FDA principal deputy commissioner and chief scientist Frank Torti, MD, MPH.
The CDC, Applied Biosystems of Foster City, Calif., and the Association of Public Health Laboratories collaborated on the development of this new test. State public health laboratories in Virginia, Iowa, California, Massachusetts, Wisconsin, and Washington performed clinical evaluations of the new flu panel.
Scientists around the world are concerned that the H5N1 virus could one day mutate and acquire the properties needed to quickly spread between people, resulting in a pandemic. H5N1 viruses circulate widely in birds in Asia, Africa and Europe and have caused human illness and death. These viruses have never been detected in the Americas.