Doctors advise on right way to swab
Testing for COVID with a home test is tricky
So, you’ve got your hands on a COVID-19 self-test because you think you, too, have been exposed to the virus as cases spiral upward in the nation, Ohio and Kentucky, and the Cincinnati region.
These test kits can be hard to find. Prices are going up.
You don’t want to blow the testing process, so maybe you’ll research the best way to swab. Should you check out a Youtube video? Search online for physicians’ opinions? Or look at the box instructions?
You might do all of the above, but Cincinnati area doctors familiar with the tests and the U.S. Food and Drug Administration caution that the latest tips online aren’t always ideal.
One is to get a throat swab or use a nasal swab as a throat swab.
Dr. Carl Fichtenbaum, an infectious disease expert at UC Health and the University of Cincinnati College of Medicine, disagrees.
“Throat swabs are not very effective and there are molecules that sometimes interfere with the test and make it invalid,” Fichtenbaum said. “Just the nose.”
The FDA has issued safety concerns about self-collection with throat swabs: They’re more complicated than nasal swabs and if used incorrectly can harm the person getting swabbed, FDA spokesman Jim Mckinney said. He also noted that the Centers for Disease Control and Prevention recommends that throat swabs be collected by a trained healthcare provider.
“I would do the nasal swab only,” said Dr. Barry Wendt, an internist with St. Elizabeth Healthcare.
The bigger problem, he said, is getting the nose swab right.
“It’s important to get it in deep enough,” Wendt said. “I would bet there are a lot of false negatives because patients don’t.”
The self-administered COVID-19 antigen tests are designed to collect viral proteins. There are saliva tests, but the most common rapid, home tests are nasal swabs. Instructions provided with the tests specify how to use them.
Generally, users are advised to gently insert the “entire soft end” of the swab into the nostril. Do not touch that end before inserting it. Rotate the swab slowly and gently for about 15 seconds, and repeat the process in your other nostril, a Centers for Disease Control and Prevention guide shows. There have been physicians who’ve suggested that a throat collection is more accurate.
When should I take the test?
“Make sure you have two days of symptoms before testing,” Wendt said.
Fichentbaum explained: “The rapid tests appear to be most effective on those who are sick, two to four days into symptoms.” If you’re not feeling sick, the test’s sensitivity is reduced.
Swab the nose or throat?
“Some doctors have suggested that people swab their throats based on anecdotal evidence that there is a higher viral load in the throat,” said Dr. Imran Naqvi, vice president of medical affairs at the Jewish Hospital – Mercy Health. “I agree with the FDA that people using these tests should follow the box instructions since that is the way these tests were designed to be used.”
Dr. James Kaya, medical director at Clermont County Public Health, said that while he has no personal experience using throat swabs, and reminded that current over-the-counter COVID-19 rapid tests “do not have EUA (emergency use authorization) for throat samples.”
So how did this debate start? Kaya said there’s “promising data” showing that omicron is different from the delta variant in that it has more upper respiratory tract symptoms than lung symptoms.
“Studies from other countries suggest throat samples may result in slightly earlier positive result compared to nasal specimen for omicron variant,” he said. “Some experts are suggesting that the difference between nasal vs. throat specimens may not be that great to prefer one over the other, so the proper question is not nasal vs. throat, but whether nasal plus throat samples will yield a quicker positive result in infected individuals.”
Be wary of claims about tests
Watch out for this myth: USA TODAY, along with other fact-checkers, has debunked the conspiracy theory that vaccines will be used to implant microchips. There is no evidence to suggest that COVID-19 tests could be “implanting something.”
Other advice popping up online includes avoiding acidic beverages – coffee, fruit juices – before swabbing and not brushing your teeth first.
Wendt said he’s never heard of such a thing. Fichtenbaum questioned the advice, saying, “The only thing I would avoid is nasal sprays, nasal washes or blowing (your) nose right before the test.”
These claims about coffee, fruit juicesand soda pop have been debunked by media fact-checkers.
Finally, do at-home tests work?
Some of the discussion may be prompted by questions about whether the DIY tests really can diagnose COVID-19.
They can, both federal health officials and Cincinnati area specialists say.
“The FDA stated that antigen tests may have reduced sensitivity, particularly early in the course of the disease,” Fichtenbaum said. “The reality is that we don’t have side-by-side data comparing PCR (polymerase chain reaction) NAAT (nucleic acid amplification test) testing to rapid at-home antigen tests.” But the tests are far from useless. Fichtenbaum said the COVID-19 antigen tests are about 75% effective in detecting COVID.” That’s good, he said, though some antigen tests rate 95% or greater accuracy, leaving people to question the value of the COVID-19 tests. “The jury is still out if omicron and rapid tests work well together.”