New Test Quickly Spots Bird Flu in People
It should benefit patients and help control potential outbreaks, officials say
FRIDAY, Feb. 3, 2006 (HealthDay News) -- U.S. health officials announced Friday the approval of a new rapid lab test to detect bird flu in humans.
The test works by detecting viral genetic material, which, in turn, is used to demonstrate the presence of bird-flu infection.
It was developed by the federal Centers for Disease Control and Prevention and was approved by the U.S. Food and Drug Administration within two weeks.
"The approval provides CDC and its Laboratory Response Network with a powerful tool to allow early detection of avian flu should it appear in the United States," Dr. Steve I. Gutman, director of the FDA's Office of In Vitro Diagnostics Device Evaluation and Safety at the Center for Devices and Radiological Health, said at a press briefing.
"Timely detection of avian flu has obvious benefit to patients who have been infected and can help stop the spread of this disease," he added.
Since December 2003, more than 150 human cases of bird, or avian, flu caused by the H5N1 strain of the virus have been reported, mostly in Southeast Asia, Turkey and Iraq, and 85 people have died. The virus is especially virulent, killing more than half of those infected.
So far, exposure seems to have been limited to contact with infected poultry. Experts are concerned, however, that the virus will mutate and gain the ability to skip easily and quickly from human to human, triggering a pandemic.
The virus is not currently circulating in North America.
The new test, called the Influenza A/H5 (Asian lineage) Virus Real-time RT-PCR Primer and Probe Set, will be used in the CDC's network of about 140 labs in all 50 states.
A person with suspected bird-flu infection would provide a sample of a respiratory secretion (either through a swab or aspiration) to health-care professionals at a clinic, emergency room or doctor's office. That sample would then be sent to a lab, which should be able to perform the test and generate results in two to four hours, Gutman said. Previous technology required a minimum of two to three days, he said.
Stephan S. Monroe, acting director of the CDC's Division of Viral and Rickettsial Diseases, said 87 percent of the U.S. population lives within one hour of one of these labs, so getting a sample to a lab for testing should not cause a time lag.
There are some caveats with the test, however. It generates a "presumptive" positive rather than a definitive positive, meaning that further testing and "careful interpretation" would still have to be conducted by the CDC.
"A negative test does not conclusively rule out the possibility of avian flu," Gutman explained. "It's not intended for general screening of individuals in the general population. It's intended for use in patients with severe respiratory illness who have had a risk of exposure, such as travel or contact with suspicious birds."
Because the CDC is part of the World Health Organization's collaborating network for influenza, the test will be shared with labs around the world.
The test was developed solely with government funding, but officials said the private sector had expressed considerable interest. Officials also said the expedited review process would be open to other companies developing diagnostic tests.
The speed of the test's approval was exceeded only by that of the West Nile virus test, which took four days.
"It's not a record but it's still awfully good," Gutman said.
Learn more about bird flu and a possible pandemic from the World Health Organization.