Los Angeles County will discontinue a coronavirus test used at its pop-up testing sites after the Food and Drug Administration issued a warning last week about the accuracy of its results, health officials said Sunday.
The change is expected to start this week and was decided on “as a precaution,” according to a statement from the county Department of Health Services.
Last week, the FDA raised concerns over the coronavirus polymerase chain reaction (PCR) test, which is typically performed by collecting a throat or nasal swab, produced by the company Curative, over the “risk of false results, particularly false negative results.”
FDA officials said the risk of a false negative could include “delayed or lack of supportive treatment, lack of monitoring of infected individuals and their household or other close contacts for symptoms resulting in increased risk of spread of COVID-19 within the community, or other unintended adverse events.”
Curative officials said via email Sunday that, on average, their tests detect slightly more cases than the rest of California’s testing.
“While all tests have the potential for false negative results, public data suggests Curative’s positivity rate largely agrees with other labs,” said Pasquale Gianni, communications manager at Curative.
Health experts, including Dr. Bud Lawrence at Henry Mayo Newhall Newhall Hospital, have said that user error could be why some tests falsely return negative, as people are allowed to self-swab.
Health Services said in its statement that all COVID-19 tests have a risk of negative results because the sensitivity depends on how well samples are collected.
“There is no reliable way to detect early infection, meaning that infection often spreads before symptoms develop,” read the county statement. “Nevertheless, PCR tests, including the Curative test, remain better at detecting disease than other tests, including rapid tests.”
The county used a limited number of Curative’s coronavirus tests at its pop-up testing sites since mid-December. Between Dec. 13 and Jan. 2, more than 24,200 Curative tests were administered, or about 10% of all tests conducted during that time frame.
“The Curative tests will be replaced with Fulgent Genetics tests,” county officials said.
The FDA recommended that health care providers consider retesting patients using a different test if they suspect inaccuracy and that patients and caregivers talk to their providers if they have concerns about their test results. If someone tests negative, the county recommends self-isolating for 14 days after exposure or 10 days after symptoms start.
