Kristen Cardillo, BD’s vice president of global communication, said the company was aware of the situation in Nevada and was “conducting thorough investigations.” She added that “based on the information in the directive and the total tests performed, we believe the rate of reported false positives is well within what we would expect for the BD Veritor System.”
Representatives for the Department of Health and Human Services did not respond to requests for comment.
Concerns have also been raised about the ability of antigen tests to accurately pinpoint infections, especially if administered during a period when a person harbors low levels of the coronavirus. BD’s test is advertised as having a false negative rate of 16 percent. Quidel’s is just above 3 percent. The directive from Nevada’s department of health did not report whether the negative antigen test results from nursing homes — there were nearly 3,700 such results — had been confirmed by P.C.R.
In a call with LeadingAge members on Monday, Adm. Brett Giroir, who has been leading the nation’s testing efforts, said antigen tests were “clearly a lifesaving option,” and for many facilities the best test available, given the delays, expenses and shortages that had plagued P.C.R. tests.
“It is perfectly acceptable for congregate care, particularly nursing homes, to use an antigen test, even if they are, quote, off-label,” Dr. Giroir said in the interview. “Just because they don’t have an authorization doesn’t mean they’re not good for it.”
In response to questions about false positives, Dr. Giroir reminded LeadingAge members that in places where the coronavirus is scarce, false positives should be expected to outnumber true positives and do not necessarily invalidate the usefulness of a test. “That’s a function of the way life is,” Dr. Giroir said.
The halt to antigen testing in Nevada’s nursing homes comes just days after health experts criticized the White House, which is now in the midst of a coronavirus outbreak, for a misguided overreliance on rapid testing. For months, officials used two products made by Abbott Laboratories, the ID NOW and the BinaxNOW, to test people without symptoms — another off-label use — while eschewing masks and physical distancing. In September, the White House also began distributing millions of BinaxNOW tests to communities across the country, including nursing homes around the country.