How Long Can You Continue to Test Positive for COVID-19?

With New Year's Eve around the corner following holiday gatherings this month, many who contracted COVID-19 might be wondering how long they could test positive.

With the more recent strains of the virus, the incubation period, or the time between when you're infected to when symptoms appear, has dropped to around three days, Dr. Allison Arwady, commissioner of the Chicago Department of Public Health, has said. Most elements with these strains have moved faster compared to others, the doctor noted.

Still, official guidance from the Centers for Disease Control and Prevention states the incubation period remains two to 14 days for all COVID-19 infections. Typically, with BA.4, BA.5 and some BA.5 subvariants, most people are testing positive about three days after contracting COVID, although some can still produce a positive test result for up to 10 days, according to health officials.

While newer variants that originated from BA.5, such as XBB and BQ.1.1 are gaining prevalence in the U.S. and across the world, it is currently unknown what differences they pose compared to BA.4 and BA.5 in terms of incubation and testing.

Previously, the average incubation period for infections associated with the alpha, beta and delta variants, was said to be five days.

Regardless of the variant, a person with COVID-19 can be contagious 48 hours before they start developing symptoms, according to an article from Harvard Health Publishing at the Harvard Medical School. During this period, people may be more likely to spread the illness, as they may not be aware of the infection and taking the proper precautions.

With BA.5, also known as omicron, most transmission occurs during the one to two days before the onset of symptoms, and in the two to three days after the fact, the article stated. Based on that, what should you do if you happen to test positive?

If you receive a positive COVID test result, CDC guidance states that you should stay home for at least five days and isolate from others in your residence. You are likely most infectious during these first five days.

If you had no symptoms, you can end isolation after day 5, according to the CDC.

If you had symptoms, however, you can only end isolation after day 5 if:

• You are fever-free for 24 hours (without the use of fever-reducing medication)
• Your symptoms are improving

If you still have a fever or your other symptoms have not improved, continue to isolate until they do, the guidelines state. How severe your symptoms are can also play a role.

If you had moderate illness - such as shortness of breath or difficulty breathing - or severe illness, including hospitalization due to COVID-19, or if you have a weakened immune system, you need to isolate through day 10.

Anyone who experienced severe illness, or has a weakened immune system, will want to consult your doctor before ending isolation as you may need a viral test to do so.

Those who continue to test positive should continue masking.

"You should continue wearing a mask and wait at least 48 hours before taking another test," the CDC recommends. "Continue taking antigen tests at least 48 hours apart until you have two sequential negative results. This may mean you need to continue wearing a mask and testing beyond day 10."

If your symptoms worsen or return after you end isolation, you'll need to restart your isolation at day 0, per the guidelines.

Regardless of when you end isolation, the CDC guidelines state you should avoid being around people at a higher-risk of severe illness, wear a mask when indoors and avoid places where you are unable to mask until at least Day 11.

But, if you have access to antigen tests, and get two sequential negative tests 48 hours apart, you may remove your mask sooner.

Certain tests, however, can stay positive for some time, according to Arwady and other health officials.

PCR COVID tests, for example, can stay positive for a "very long time" after recovering from the virus because they pick up on any dead infection, she said.

The CDC has said people can test positive for up to three months after contracting an infection.

"After a positive test result, you may continue to test positive for some time after," the CDC's website states. "You may continue to test positive on antigen tests for a few weeks after your initial positive. You may continue to test positive on NAATs for up to 90 days."

Some doctors assert the safest course of action is to remain in isolation until you test negative. However, Dr. Stephen Kissler, a postdoctoral fellow at the Harvard T.H. Chan School of Public Health, said it's not unreasonable to gradually leave isolation — even if you’re still testing positive using a rapid test.

That's especially the case if you're fully vaccinated, symptoms have resolved and you continue to practice masking.