A rapid test to detect human infection with avian influenza provides preliminary results in just 4 hours instead of the standard 2–3 days, according to officials with the Food and Drug Administration and the Centers for Disease Control and Prevention.
The test is being made available to the World Health Organization and individual countries in addition to its distribution throughout the United States.
The test, developed by the CDC and rushed through the FDA approval process, is intended to detect H5 viral strains from respiratory secretions in patients suspected of being infected. Further testing is then required to identify specific subtypes such as the H5N1 subtype, which so far has been responsible for 166 human infections and 88 deaths worldwide.
“This provides a presumptive positive result, not a definitive result,” Dr. Steve Gutman of the FDA said in a teleconference sponsored by that agency. “And a negative result does not conclusively rule out infection.” He said the test is not intended as a screening tool but rather to investigate signs and symptoms of avian influenza in people who have possibly been exposed to the virus.
Within the United States, the test, which is known as the Influenza A/H5 (Asian Lineage) Virus Real-Time RT-PCR Primer and Probe Set, is being distributed to about 140 designated laboratories in the Laboratory Response Network. About 87% of the country's population lives within 1 hour of such a lab, said the CDC's Steve Monroe, Ph.D. Physicians wishing to test a patient should send their samples directly to the closest Laboratory Response Network lab.
The availability of the test provides a powerful tool for the timely detection of avian influenza, Dr. Gutman said.