(WXYZ) — PCR is considered the gold standard for testing COVID, but it does mean waiting in a line to get tested and then days for the results. That’s why home testing kits are convenient and easy to use, but some experts say they too come with drawbacks.
"We’ve had a number of people take rapids when they’ve been positive on the PCR, and it's pretty striking how often the rapid is negative," said LynxDX Inc CEO Yashar Niknafs.
Niknafs runs a COVID-19 testing lab in Ann Arbor, and he says if you test positive on a home testing kit, then rest assured you have COVID-19. The concern kicks in when the kit shows negative.
"If people are sick and do a rapid, and their rapid is negative, and it's perceived as a green light to go hang out with people, it might even accelerate the spread of COVID," says Niknafs.
Medical Director Dr. Asha Shajahan from Beaumont Grosse Pointe Hospital says rapid tests have a 20% false-negative rate.
"Because the viral load is not high enough for it to show up on the test," says Shajahan.
In layman's terms, a rapid or antigen test is like a home pregnancy test. You drop the sample on a test strip, and if you are infected with the virus, the strip shows a positive sign.
In a PCR test, your sample is analyzed in a lab. That’s why even the smallest amount of the virus can be detected, resulting in a better accuracy rate.
In a rapid test, you need a certain amount of the virus to be present in the sample, or else you are getting negative.
"There is no way to know how accurate it is, and we don’t know how people are going to use the test, and then there is a whole other issue, its surveillance and tracking," said Niknafs.
For now, home kit users are recommended to report their results online. Even if one chooses not to, the state’s infection rate becomes inaccurate.
"We wanna keep track of how many people have COVID. This is what guides our guidelines and also keeps track of what's happening in our local community," said Shajahan.
And to make matters worse, according to Niknafs, the technology behind the home testing kits hasn’t evolved.
"So it's not like they are shipping these kits because there was some revolutionary thing that occurred, and all of a sudden the rapid tests are really good," says Niknafs. "That did not happen. The kits you are going to get are the same kits that were developed 18 months ago."
Both Niknafs and Shajahan say getting tested is still better than not getting tested. So if a home test kit is available to you, make the most of it.
