In a breakthrough for diagnostics amid the Wuhan coronavirus crisis, the U.S. Food and Drug Administration (FDA) has issued an emergency use authorization (EUA) paving the way for use at qualified labs of a diagnostic test developed by the U.S. Centers for Disease Control and Prevention (CDC).
Guided by sequencing information made public by Chinese authorities, the CDC developed a real-time reverse transcription polymerase chain reaction (RT-PCR) diagnostic panel for the 2019 novel coronavirus (2019-nCoV). Up until now, the agency has said that all tests were to be performed at its own facilities. Testing involves screening respiratory secretions, and the agency had shared protocols for labs and guidance on the preparation of specimens.
In a February 4 announcement, the FDA explained that the test may now be used by qualified laboratories that are certified to perform high complexity testing in screening patients who meet the CDC criteria for 2019-nCoV testing. A positive test indicates infection is likely, but negative results do not preclude infection and should be viewed in the overall context of a patient's condition and history, the agency said in a statement. Symptoms of 2019-nCoV include fever, coughing, and difficulty breathing, and people who have traveled from Wuhan are at highest risk.
The CDC has said that once an EUA is issued by the FDA, it will distribute the diagnostic panel and most of the associated reagents, using its international reagent resource as a distributor. Labs will use their own RT-PCR equipment and extraction kits.
The emergency use authorization is an important step that will open up novel coronavirus testing and relieve the backlog at the CDC, commented Bruce Carlson, publisher of Kalorama Information, a sister company of LabPulse.com.
It should be noted that testing is limited to labs certified for high complexity testing, with the most advanced trained technicians, to ensure accurate results from a well-conducted mix, sample prep, test run, and test interpretation, Carlson said. Also, accuracy is just as important for negative results as in the diagnosis of positive cases, he added.
The FDA's move follows decisions to declare the coronavirus a public health emergency by the U.S. Secretary of Health and Human Services (HHS) on January 31 and the World Health Organization (WHO) on January 30. The FDA had pledged a range of countermeasures against the virus, including making diagnostics more widely available, on January 27.
According to the WHO, 20,630 cases globally had been confirmed as of February 4, with 20,471 reported in China. The global death toll had climbed to 425, all but one of which were reported in China. In the U.S., 11 cases had been confirmed.
"At this time, federal health officials continue to believe that the threat to the general American population from this virus is relatively low," the FDA said in its latest statement.
During past public health crises -- for example, with the Ebola virus threat -- the EUA was crucial for providing temporary access to unapproved diagnostics quickly. Typically, emergency access lasts as long as a threat persists and if a similar test has not been cleared or approved by the FDA.