The COVID virus is a bit slower to replicate than other common viruses, so testing two or more days after symptoms start gives more accurate results COVID tests are designed to spot heavy viral loads -- in other words, those who are most infectious Other viruses, like RSV or flu, are easily spotted as soon as symptoms begin WEDNESDAY, June 26, 2024 (HealthDay News) -- The COVID virus, or rather people's immune response to it, has changed and it might be prudent to wait a couple days after symptoms start before taking a COVID test, researchers report. “For COVID, we found that if you only have one test, it’s best to wait two days after symptoms arise to use it, because the virus is unlikely to be detectable until then,” said study first author Casey Middleton , a PhD student in the department of computer science at the University of Colorado Boulder (UCB). “For flu and RSV, you’re best off to take that rapid test when you first feel symptoms," Middleton added in a university news release.
She and her colleagues took what they knew about Omicron virus variants of the COVID-19 virus, typical patient behavior and other factors, and they created a computer model to gauge when testing might be most accurate. They found that if you take a COVID rapid test very soon after symptoms begin, the test misses infection 92% of the time. Taking the test two days after symptoms arise knocks that false-negative rate down to 70%, and your chances of identifying COVID accurately rise e.
