As the omicron coronavirus variant continues to spread across the country, making up a majority of COVID-19 infections in the U.S., people are getting tested in droves.
But the surge in COVID infections this winter has left the country grappling with a shortage of testing resources.
Americans have been forced to wait in lines for hours to get a PCR test and then wait even longer for those tests to be processed, leaving many to wonder if their test results are even relevant by the time they receive them. Rapid antigen tests, which can administered at home, have been in short supply in stores all over the country for weeks.
If you are lucky enough to have access to affordable and reliable testing resources near you, you might be wondering how to make proper use of them, especially in the wake of changing recommendations from the Centers for Disease Control and Prevention on testing and isolation, which have been criticized by public health experts, who say the guidelines are unclear and confusing.
Here are some frequently asked questions on COVID-19 tests and when to get them.
You’ve been exposed to COVID-19. When should you get tested?
If you’ve been exposed to COVID-19, don’t run to get tested right away — the earliest you can test positive for COVID is between 24 and 48 hours after exposure, according to Verywell Health.
Instead, focus on quarantining, and make sure to wear a good mask — preferably, a 3-ply surgical mask, KN95 or N95 — around other people to reduce the risk of spreading the virus.
If you’ve received a booster dose of the vaccine, or received your initial vaccine series within the last six months, the CDC recommends that you wear a mask around other people for 10 days and get tested on the fifth day after exposure at the latest.
Other health experts, however, say that you can test positive earlier than that, and that the best days to get tested are days 2, 3 and 4 after exposure, or within 48 to 72 hours, according to The New York Times. In other words, experts suggest that waiting for a full 5 days may be too long, and you risk spreading the virus to others in the meantime.
Waiting at least 48 hours to get tested gives your body time to develop enough of a viral load for a test to detect — if you test too early, you run the risk of testing negative early on only to become symptomatic or infectious soon after.
You have COVID-19 symptoms. When should you get tested?
If you’re already symptomatic, you “probably have enough virus in your system to make a positive test,” Andy Pekosz, a virologist at the Johns Hopkins Bloomberg School of Public Health, told Insider.
Rapid tests are generally better at detecting the virus in people who have noticeable symptoms than they are at picking it up in asymptomatic people, according to Today. But if you test negative on a rapid test while exhibiting symptoms, don’t assume you don’t actually have COVID-19 — you might just have a false negative.
“If it’s positive, that’s fine. You’re good,” Dr. Sheldon Campbell, associate professor of laboratory medicine at Yale School of Medicine, told Insider. “But if it’s negative early in symptoms, sometimes the viral load isn’t up quite yet. And late in disease, when people start getting really sick, sometimes the viral load’s already fallen.”
If you think you’ve received a false negative from a rapid test, you should get a PCR test, if possible, to verify whether or not you actually have COVID-19. If rapid tests are the only option, El-Sadr recommends taking two rapid tests 24 hours apart, Today reported.
You think you might have COVID. Should you get tested?
If you’re asymptomatic, you can still spread the virus to other people — and there’s no telling how it may affect them. Because of this, it’s important to know whether you’re carrying the virus around or not, if possible.
You should quarantine and get tested after an exposure even if you don’t develop symptoms, according to the CDC. When you’re done quarantining, you should still monitor yourself for symptoms.
Experts also note that some people might think they’re asymptomatic because their symptoms are so mild, they manifest in ways that can easily be mistaken for other issues — for example, a scratchy throat or runny nose that feels like seasonal allergies, according to Today.
Dr. Wafaa El-Sadr, professor of epidemiology and medicine at the Columbia University Mailman School of Public Health, told Today that “this is a time when we should have a low threshold for getting tested for COVID-19.”
When should I get retested?
If you’ve been exposed, your first test comes back negative and you have no symptoms, you should still get tested again two or three days later — while taking precautions, such as masking and reducing contact with other people — before you consider yourself in the clear, the New York Times reports.
If you start exhibiting symptoms after a negative test, you should also get retested after a few days. It’s possible that your first test was a false negative, and taking additional tests will provide more clarity. If you test positive, you should isolate yourself for at least five days and then get tested again if you can, Dr. Prathit Kulkarni, assistant professor of medicine in infectious diseases at Baylor College of Medicine, told The Fort Worth Star-Telegram.
If you test positive again, you should isolate yourself for at least another five days and then try again, Kulkarni said. False positives are rare, and getting a positive result means you likely still have COVID-19, according to NPR.
If you test negative, you can stop isolating, but you should still wear a mask around others and keep a physical distance from them.
This story was originally published January 11, 2022 3:41 PM.