Cold, flu and COVID-19 season is finally starting to wind down in the U.S. But, with spring allergies on the way, it's still important to know how and when to use tools like at-home tests to determine what might be causing that stuffy nose and fatigue.
Your results — whether positive or negative — are only helpful if you know how to interpret them.
While most people will clear the virus within 10 days, some people may keep testing positive for longer than that, experts tell TODAY.com. And if you keep testing positive for 10 days or more, the safest approach may not be obvious.
Deaths and hospitalizations due to COVID-19 are on the decline after a winter surge. And the Centers for Disease Control and Prevention scaled back the isolation guidelines for people who test positive, putting them in line with recommendations for other respiratory viruses like the flu.
But, knowing that COVID-19 is still out there, it's important to resist "COVID fatigue" and to "still not become complacent," Dr. Diana Cardona, a member of the College of American Pathologists Board of Governors, tells TODAY.com.
"The worst thing for us to do as a society is forget about it," says Cardona, who is also the vice chair and director at Duke Health Anatomic Pathology Laboratories.
The virus poses particularly serious risks for certain populations, including immunocompromised people and older adults. And even young, healthy people can develop potentially serious complications, such as long COVID. Take advantage of precautions — updated COVID-19 vaccines, masks and testing — to keep yourself and those around you safe.
Here's what to know about when to take a COVID-19 rapid test, how to correctly interpret the results and when it’s OK to stop isolating — even if you’re still testing positive at 10 days and beyond.
How long can you test positive for COVID-19?
Most people will stop testing positive on a rapid antigen COVID-19 test within about 10 days, Cardona says. "Within 10 days after your initial positive test, you should convert back to negative," she explains.
But it’s not unheard of for people to test positive for longer than that on a rapid COVID-19 test, even up to 14 days, Stephen Kissler, Ph.D., an assistant professor of computer science at the University of Colorado Boulder, tells TODAY.com.
“We see a ton of variation between people in how long they test positive,” says Kissler, whose work involves modeling the dynamics of epidemics. “While that average is closer to six to 10 days, there are people who will hang on for longer than that.”
The truth is that there are a lot of factors that can affect how long any given individual may test positive.
For instance, it's possible to develop COVID rebound, Cardona says. This occurs when people "pop back up as being positive even after a negative test," she explains. "It's not super common, but it does actually happen." This can occur with or without taking the antiviral medication Paxlovid, and it may come with or without the return of COVID-19 symptoms.
And, when it comes to PCR tests, which look for the virus’s genetic material, people may test positive for much longer than they're contagious, Dr. Alberto Paniz-Mondolfi, associate professor at the Icahn School of Medicine at Mount Sinai, tells TODAY.com.
“You can still have positivity that may persist for weeks and even months,” he explains. “We know that (PCR tests) can definitely stay positive way, way longer than somebody is infectious, let alone symptomatic,” Cardona agrees.
When to take an at-home rapid test for COVID-19:
If you develop any symptoms that might signal COVID-19, taking a test can help determine what to do next, the CDC says.
Despite changes in which coronavirus variants are circulating now, the most common symptoms remain largely the same. Be on the lookout for cold- and flu-like symptoms, including sore throat, sneezing, congestion, runny nose, cough, muscle aches, hoarse voice and an altered sense of smell.
Some of those symptoms — congestion, sore throat, cough, fever — might be easily confused with other common illnesses, such as the flu, allergies, RSV or the common cold. But it's a good idea to take a test to help rule out COVID-19 first, even if you may just be dealing with seasonal allergies.
The latest CDC guidelines suggest taking more precautions against COVID-19, including testing...
- Before gathering with others.
- When respiratory illnesses are making a lot of people sick in your area.
- If you or those around you were recently exposed to a respiratory virus, are currently sick or are recovering from a respiratory illness.
- If you or those around you have risk factors that increase the chances for severe disease.
If you test positive for COVID-19...
If you test positive for COVID-19 on a rapid antigen test, you should trust that result. “If it actually is positive, that really does indicate that you are infectious and that your risk of spreading it to others is high,” Cardona says.
And remember that even a faint line on a home COVID-19 test should be considered positive. If you’re not sure whether your test is truly positive, you should check with your doctor, get a PCR test or take a second rapid test the next day (and behave like you really do have COVID-19 in the meantime).
From there, you should follow instructions from your doctor and the CDC about isolation to avoid getting other people sick.
The most recent CDC guidelines state that you should stay home and away from others while you're sick with any respiratory virus, including COVID-19. And you shouldn't go back to your usual activities until your symptoms are getting better overall and you've been without a fever for at least 24 hours without the use of fever-reducing medications.
Exactly how long that takes will be different from person to person.
Even when you return to your normal activities, the CDC recommends keeping up certain precautions, such as masking, staying diligent about hand hygiene and testing, for another five days.
If you start to feel sicker again after going back to your usual activities, the CDC recommends staying home (for at least 24 hours) until you've met the earlier criteria about fevers. Then, take precautions around others for another five days.
And if you never had symptoms of a respiratory virus but still got a positive test result, you should assume that you're contagious. For the next five days, you should follow those same precautions whenever you're around others, the CDC says.
After you test positive, should you keep taking at-home COVID-19 tests?
If you get a positive test on a home rapid antigen test, you can trust the result, experts tell TODAY.com, provided you performed the test correctly.
That means you probably don't need to keep testing yourself every single day throughout your illness. Just follow your symptoms, count the days — and continue to mask up around others. But those with more moderate or severe cases and those who are immunocompromised may need to perform more tests to leave isolation based on advice from their medical team, the CDC advised previously.
In the event that your test is negative even though you have noticeable COVID-like symptoms or you were exposed to someone with a confirmed case, the FDA now recommends taking a second test two days later. Depending on your symptoms and exposure, you may want to take a third rapid test another 48 hours after that, the FDA says.
"If you have high-risk features, such as (a known COVID-19) exposure or symptoms, and it's negative," Cardona says, "either repeat testing the next day or, better yet, just go to your doctor and get the more sensitive (PCR) tests that are available in doctors' offices."
Does a positive COVID-19 test after 10 days mean you're still contagious?
As long as you continue to test positive on a rapid at-home test, you should still consider yourself potentially contagious. “If you are still positive late in your disease or even though you’re symptom-free, that test is indicating that you still are shedding something,” Cardona says.
But, experts tell TODAY.com, that you are likely to be less infectious after 10 days than you were at the beginning of your infection.
"In theory, if you're getting better, your body's attacking the virus and getting rid of it," Cardona says. So you're less likely to spread the virus to others as your body clears it. That said, the safest strategy is to continue to isolate until you’re no longer testing positive, the experts agree.
If you decide to see people when you're still testing positive, you should try to take other measures to prevent the spread of the virus.
"Is the risk zero? No," Cardona says. "But if you take the necessary precautions — wearing a mask, distancing yourself if possible from others — that would still be the recommendation."
Ideally, if you have access to enough tests, you wouldn’t stop masking until you get two consecutive negative rapid test results taken 48 hours apart, Dr. Emily Volk, past president of the College of American Pathologists, tells TODAY.com. But “this is asking a lot of folks,” she adds. This approach may mean you wear a mask around others for longer than 10 days.
The truth is that “not everybody’s going have access to serial antigen testing like that,” Volk says. “It’s probably not realistic that most of the population is going to follow those instructions, even though that would be the best scenario possible.”
If you must interact with others before testing negative, make sure to wear a high-quality mask, maintain distance from other people when you can and avoid spending time in enclosed spaces around other people.
After 10 days, it's likely that "you're good to go," Paniz-Mondolfi agrees, and he says you're "even better to go" if you keep practicing those precautionary measures — especially wearing a mask — until you get a negative test result.
And, of course, if you're concerned about how long you've been testing positive, check in with a health care provider for guidance on your individual situation.