FDA Clearance for Avian Influenza A Rapid Test

Laurie Barclay, MD

April 09, 2009

April 9, 2009 — On April 7, The US Food and Drug Administration (FDA) cleared for marketing a new, more rapid test to identify influenza A/H5N1, a predominantly avian subtype that can also be pathogenic in humans. In less than 40 minutes, this AVantage A/H5N1 Flu Test (Arbor Vita Corp) can detect NS1 — a specific protein characteristic of the influenza A/H5N1 virus subtype — in throat or nose swabs from patients who have flu-like symptoms. In contrast, previous cleared tests take up to 3 or 4 hours to yield results.

"This test is an important tool to help quickly identify emerging influenza A/H5N1 infections and reduce exposure to large populations," Daniel G. Schultz, MD, director of the FDA's Center for Devices and Radiological Health, said in a news release. "The clearance of this test represents a major step toward protecting the public from the threat of pandemic flu."

Although the H5N1 subtype is mostly found in birds, humans have contracted the virus from infected poultry. Of the few avian influenza viruses that have infected humans, the H5N1 subtype is responsible for the greatest number of diagnosed cases of serious morbidity and mortality, according to the US Centers for Disease Control and Prevention.

If influenza A/H5N1 were to mutate further in a way that would facilitate human infection, an influenza pandemic could result. The World Health Organization states that the 412 confirmed human cases of infection from this virus are almost all in Asia and northern Africa, and that human infection with this virus subtype has not been diagnosed in the Americas.

Clinical studies to date have shown that the new test correctly identified the absence of infection in more than 700 specimens and correctly detected the presence of influenza A/H5N1 virus subtype in 24 cultured specimens from infected patients.