Ask a Doc: At-Home Test Kits for the Flu and COVID-19

The Food and Drug Administration (FDA) last week authorized the first over-the-counter (OTC) at-home test that can detect – and differentiate between – the flu and COVID-19. Raymond A. James, D.O. and medical director of the Boca Grande Health Clinic tells us what to know about this and what to keep in mind when using any of the at-home tests.

Who makes the new COVID-19 and Flu Home Test kit and how does it work?

Lucira Health, a medical technology company based out of Emeryville, CA, is behind the new COVID-19 and Flu Home Test kit. The company bills itself as developers of “innovative infectious disease tests to make lab-quality diagnostics more accessible.” The new OTC combo nasal swab test kit recently authorized by the FDA can be used at home to detect Influenza A, Influenza B and COVID-19. Test results display in about 30 minutes. Unlike today’s at-home COVID-19 antigen test, the Lucira kit is considered a nucleic acid amplification test (NAAT) similar to a PCR (Polymerase Chain Reaction) test.

Lucira Health began making its combo test available in Canada in August 2022. These kits are not yet available in the United States, so we may have to wait until next year’s flu season to see them in real action here.

What’s the difference between a home test and what’s done in a lab?

Home COVID-19 tests are not nearly as accurate as PCR tests used at hospitals and at the Boca Grande Health Clinic, but they are quick and portable and provide good screening. We recommend testing the day you feel sick. Home tests rarely have false positives but can miss an illness with low viral load. If you are positive on a home test with symptoms, then you have that illness. PCR tests are more sensitive because they amplify the genetic material from a virus. The Clinic can perform a four-in-one rapid PCR test to detect SARS-CoV-2, Influenza A, Influenza B and RSV. It’s a simple nasal swab done at the Clinic and test results are available in under 40 minutes.

What does it matter if it’s the flu or COVID-19? Either way I have to wait it out until I feel better.

During times of the year when we see high rates of various upper respiratory viral infections, it can be hard to determine what you have based on symptoms alone. Especially right now when the Red Tide we’re experiencing is high. Knowing which respiratory illness you have matters since it affects treatment. And that’s why it’s important to get tested. Lots of infectious disease specialists are telling us that the U.S. must do better at testing to identify pathogens. Knowledge is power.

If positive for COVID-19, we consider Paxlovid antiviral therapy if indicated. If positive for Influenza, we consider Tamiflu antiviral, although not as powerful. It’s important to remember that symptoms of sore throat, body aches, headache, cough and cold symptoms should cause you to isolate to avoid spreading your illness to others, no matter the cause, and do not return to interacting with others until you’re feeling back to normal for 24 hours. If you have COVID-19, we still recommend masking for five more days to protect others. Be sure to check in with your primary care physician to discuss your symptoms and treatments available.

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About the Author

Raymond A. James, D.O.

Dr. James joined the Clinic in March 2018 . A graduate of Des Moines University College of Osteopathic Medicine, he completed his residency at Metropolitan Hospital in Grand Rapids, Michigan. He is board certified in emergency medicine and has been awarded fellowship status by the American College of Emergency Physicians. Throughout his medical career, Dr. […]