Is it the flu or is it COVID? One at-home test can tell you

With the flu season getting underway, and COVID-19 still circulating, if you get sick you might wonder: 'Which virus got me this time?' Until now, sick people who wanted to get tested had to crawl out of bed and sit in a waiting room surrounded by other coughing, sneezing people.

"You may have a fever or aches and pains. You may have nasal congestion," says Courtney Lias, who helps regulate tests at the Food and Drug Administration.

She says knowing what you've got helps answer a lot of questions. "What types of precautions should I take? How should I be taking care of my health and the health of my family?" Lias says.

This year testing got easier. For the first time, new home tests — available at pharmacies without a prescription — can test for both the flu and COVID simultaneously.

Lias and others say the new tests are a game-changer.

"I think it's a very exciting development just in time for this fall's respiratory virus season," says Lias. "It will really enable people to get through this season with a little bit more peace of mind."

The tests are very reliable — they rarely say someone's positive when they're really negative or vice versa, according to the FDA. If you test negative but are still having symptoms that feel like COVID or the flu a couple of days later, doctors recommend taking a second test.

The tests cost about the same as a COVID test — about $15 each — which can be less than the copay for going to a doctor.

The FDA has given the green light to nine over-the-counter flu and COVID tests so far, including the first that recently received full FDA authorization. The others received a more contingent "emergency use authorization."

All but one of the new tests are "antigen" tests, which means they work just like the do-it-yourself COVID tests people learned to use during the pandemic. First you swab inside your nose then test a few drops of the sample. One of the tests is a "molecular" test that uses different technology.

Within 15 to 30 minutes, the test will indicate whether you're positive for the SARS-CoV2 virus, which causes COVID, or one of two strains of flu virus.

"This is a real landmark shift in the way that we can diagnose these viral symptoms," says Dr. Greg Martin, who studies tests at Emory University.

"Having these tests available is going to be really helpful to people," Martin says. "They'll have their result really quickly and they'll be able to help make a decision either on their own or by contacting their physician so that they can decide what treatment is necessary and get that started as quickly as possible."

People who test positive can ask their doctor to call in a prescription for antiviral medications like Paxlovid for COVID or Tamiflu for the flu, if they need medication. Those drugs work best if started within a few days of the symptoms starting. The new tests discriminate between influenza A or influenza B. Flu A tends to make people sicker than flu B, so knowing which one you have can help your doctor decide what you need to do.

The tests can help people take steps to protect those around them more quickly, according to Dr. Chaz Langelier, an infectious disease physician at the University of California, San Francisco.

"Understanding if you're infected early can also more effectively help prevent transmission to others," Langelier says.

"Instead of walking around with an infection for several days wondering if you have flu or COVID you can know right away."

So people can choose to put on masks, or work from and avoid going into the office and infecting others, he says.

"It's really a wonderful advancement for public health and for human health."

This story was edited by Jane Greenhalgh

Copyright 2024, NPR

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