Medical experts debate effectiveness of at-home COVID testing versus PCR
COLORADO SPRINGS, Colo. (KRDO) -- Because of the highly transmissible Omicron variant, the need for testing at home is once again spiking across the nation, leaving the popular BinaxNow rapid at-home testing kit in high demand, and elusive.
However, some medical researchers think its indication of false negatives or positives is high because of the new variant.
“Even if you have a negative test you still need to be cautious, especially if your symptoms are continuing or getting worse," said Rob Welch, UCHealth's system lead for Laboratory Services. "You need to seek out a PCR test to seek out whether you have covid for sure.”
Welch said a negative result from a rapid antigen test might not be reliable, especially with Omicron.
The U.S. Food and Drug Administration published a statement in late December that says “early data suggests that antigen tests do detect the omicron variant but may have reduced sensitivity.”
Why is this?
"I mean when you look at the bins test, it is an antigen test, right? So it is depending on a certain level of antigen of it to be produced for it to be detectable on that test," he said. "But when you’re talking about PCR, that stands for polymerase chain reaction, so what you have is you're amplifying a little bit of DNA over and over again until you can actually detect it.”
Welch says this is why those in the medical field consider PCR tests the gold standard because they go through a series of lab sequences to get the most accurate results regardless of the variant type.
There's debate among some professionals weighing the effectiveness of testing when doing a throat swab compared to the standard nasal swab, with some saying that early research shows omicron may show up earlier in saliva tests.
“There is a lot of debate about that just like what you said…where is this infection in your body and historically it has been in the nasal cavity so the nasal swab has been the gold standard. But now there is concern with omicron about: is this colonizing in the throat?" Welch said. "We have done some research about it but we haven’t seen anything compelling so we will be sticking to the nasal swab but monitoring the other research closely.”
Welch says the big takeaway is this: testing is key -- take advantage of home testing to monitor, but many times you will have to seek out a lab-grade test to get definite results.
With state and federal government programs, people can have an at-home test delivered right to their door free of charge.
