The Food and Drug Administration warned patients and healthcare providers this week about the potential risks of false negative results, specifically with Curative’s COVID-19 test.
While no specific problems with the San Dimas-based company’s test were identified, the FDA did say the test must be performed in accordance with its labeling and should only be used in symptomatic people within 14 days of symptoms developing. Additionally, the FDA asks that people taking the self-administered test, be observed by a health care worker.
“When the test is not performed in accordance with its authorization or as described in the authorized labeling, there is a greater risk that the results of the test may not be accurate,” the FDA said in a safety alert Monday, Jan. 4.
False negatives can result in infected people unknowingly spreading the coronavirus and further delaying treatment, health officials warn.
Curative CEO Fred Turner said the company is aware of the FDA notice and is working to provide more information soon.
“We are confident in our data and we are working with the FDA closely on the matter,” Turner said. “Testing sensitivity and accuracy on behalf of our patients is at the heart of our work.”
The city of Los Angeles as well as other communities have contracts with Curative to perform testing at various sites. Those who set up an appointment arrive and self-administer the test by swabbing inside their mouths. Directions are given by on-site staff.
Self-administered tests are more prone to false negative results compared to tests administered by a health professional, regardless of the vendor, Riverside County Public Health Officer Dr. Cameron Kaiser said in a Thursday statement. A person can be negative one day and positive the next, even with a nasal swab test, he said.
“This is because sometimes people don’t follow the instructions precisely, even though they intend to do so,” the statement says. “If there isn’t enough of viral material in the sample for any reason, it won’t be positive. Staff members are available to explain the process to ensure residents perform the self-administered test correctly.”
The FDA is recommending medical providers use a different test if they suspect a patient’s results from the Curative test may be false. Individuals who were tested more than two weeks prior don’t need to be retested unless they show symptoms or suspect they contracted the virus.
“A negative result does not rule out COVID-19 and should not be used as the sole basis for treatment or patient management decisions,” the FDA said. “A negative result does not exclude the possibility of COVID-19.”