COVID Testing: Duration of Positive Results Explained by Experts
The duration of testing positive for COVID-19 can vary depending on the type of test used. PCR tests, considered the "gold standard," detect viral genetic material and can remain positive for up to 90 days, but that doesn't necessarily mean someone is infectious for that long. Antigen tests, which detect viral proteins, are usually less sensitive and may remain positive at seven days, but infectivity is likely diminished. If you test negative after being positive, your likelihood of being infectious is low. The CDC advises using two negative antigen tests spaced 48 hours apart to end isolation earlier. After 10 days, most people are no longer contagious, but if you continue to test positive, it's best to assume you're still infectious and behave accordingly. Retesting after five days of symptoms or a positive test with no symptoms can help guide the end of isolation.
