FDA warns healthcare practitioners of false positive COVID test results.
Abbot Laboratories has announced a recall of COVID-19 testing kits as that could generate a false positive, the U.S. Food and Drug Administration (FDA) announced. The recall is specific to Abbot’s Alinity m SARS-CoV-2 AMP and the Alinity m Resp-4-Plex AMP test kits manufactured by its lab unit Abbott Molecular Inc. This is considered a Class 1 recall, which is the FDA’s most concerning.
Last month, the agency sent a warning letter to healthcare practitioners and labs of the potential for the tests to returning false positives. The screenings use a certain type of software to be processed. The software automates the reading and can cause, according to the agency, “an overflow of one patient sample into another.” This is what could potentially result in a false read.
The FDA’s announcement explains, “The false positive results may be related to current mixing parameters of the PCR reaction mixture that may result in potential overflow that could carry over into neighboring wells in the assay reagent tray. Overflow into the wells of true negative samples that are positioned near positive samples in the assay tray could produce false positive results.”
Also last month, Abbott Molecular issued a memo asking that impacted customers disregard positive COVID-19 test results altogether until the lab was able to implement software updates solve the problem. While, according to the company, there have been no reported fatalities as a result of inaccurate reads, receiving a false positive could lead to a number of issues, including being forced to take time off of work (a loss of income) and having to pull children from school, etc.
Not only does a false read require mandatory isolation but caregivers of those who test positive have been put into a position of having to consider their own health. False reads can lead to splitting of families and the inability of vulnerable populations, such as those in nursing homes, to have visitors.
The FDA indicated it “is working with Abbott Molecular Inc. to resolve these issues. The FDA will continue to keep clinical laboratory staff, health care providers, and the public informed of significant new information.”
As early as last year, warning letters went out to individuals opting to take rapid tests for quicker results (in as little as an hour), stating that these types of tests are not processed by laboratory equipment and were generating a high number of false positives. The FDA warned that many of the false reads were associated with screening individuals without any symptoms.
Following the warning, in October 2020, officials in Nevada ordered the state’s nursing homes to stop using rapid testing altogether, citing concerns about accuracy. Approximately, “40 percent of U.S. Covid-19 deaths have come from nursing homes,” according to an analysis by the New York Times. False positives can impact investigations into the spread of the coronavirus in these facilities.