Have you used the Ellume COVID Home Test? Some are giving ‘false positives,’ FDA warns
If you recently completed an at-home COVID-19 test from manufacturer Ellume, there’s a possibility you may have received a “false positive” result, meaning you were told you have the coronavirus when you actually didn’t.
Negative test results “do not appear to be affected,” the U.S. Food and Drug Administration said in a “safety communication” released Tuesday.
The FDA warned health care workers and the public of manufacturing issues that led to the recall of “certain lots” of the tests, which have been available for over-the-counter home use since December 2020.
You can check if your test is included in the recall by comparing the lot number found on the box your test came in to the lot numbers on the company’s website.
Officials advise those who received a positive result in the last two weeks from an Ellume at-home test to contact their health care provider or a COVID-19 testing site to follow up with a molecular diagnostic test to confirm if they have the coronavirus.
If you have an unused Ellume home test that has been recalled, the FDA suggests you use the company’s app or follow directions on its website to request a product replacement.
“The FDA is working closely with Ellume to assess the company’s additional manufacturing checks and other corrective steps to help ensure that the issue is resolved,” the administration said in a statement. “The FDA will keep the public informed if significant new information becomes available.”
You should also contact a COVID-19 testing site if you received a negative test result from a different coronavirus test at the same time you got the positive result from the Ellume test.
“You should not assume that you had COVID-19 or have immunity to COVID-19,” the FDA said. “You should continue to take recommended precautions, including vaccination, to avoid COVID-19 infection, following the Centers for Disease Control and Prevention’s guidelines.”
What kind of test is the Ellume COVID-19 home test?
The Ellume home test is an antigen test that looks for specific proteins found on the surface of the coronavirus to determine if someone has an active infection from a nose swab sample. It’s for people ages 2 and older with and without COVID-19 symptoms.
Antigens are proteins that cause an immune system to produce antibodies. If there are enough of them present in a person’s biological sample such as a nasal or throat swab, they will attach to specific antibodies that are fixed on a paper strip, and “generate a visually detectable signal, typically within 30 minutes,” according to the World Health Organization.
These kinds of tests are also available for illnesses such as strep throat, influenza, tuberculosis and HIV.
But how well they work depends on when during one’s illness the test is administered, the concentration of the virus in the sample, the quality of the sample and the “precise” mixture of liquids used in the chemical analysis in the test kit, the WHO said.
Although antigen tests are usually cheaper and return results faster, they have a sensitivity that varies between 34% to 80%, according to the group, meaning “half or more of COVID-19 infected patients might be missed by such tests.”
False-positive results with antigen tests are less common than false-negatives, the FDA says, but they can occur if the antibodies on the test strip also recognize those of other coronaviruses, like those that cause the common cold.
This story was originally published October 5, 2021 at 11:44 AM with the headline "Have you used the Ellume COVID Home Test? Some are giving ‘false positives,’ FDA warns."
