It’s safe to assume that most Americans have taken a rapid test by now. They’re easy to store and come in handy in the event that someone in your household is exhibiting symptoms. Rapid tests can also be used to monitor asymptomatic illness and transmission risk following a close contact.
The process is far from complicated, doesn’t take long, and can be done safely and reliably at home. Having said that, messing up the order of the steps or failing to follow the directions correctly will impact its effectiveness. Read ahead to learn how to ensure the most accurate results on your next rapid test.
Helen Sushitskaya/ShutterstockWhat is a Rapid Antigen Test?
The CDC has since removed the word ‘rapid’ from their antigen test messaging.1 Still, most of us call the familiar virus detection devices rapid tests or rapid antigen tests.2 Rapid antigen tests are over-the-counter tools used to help diagnose symptomatic and asymptomatic illness quickly, affordably, and reliably.
No need to wait for lab results here because these tests can be administered and understood without the help of a professional. Rapid antigen tests are easy to store, and can be done at home, at school, or at work with ease.
How Does it Work?
Though they aren’t exactly as reliable as the lab-centric PCR tests, rapid antigen tests do serve a practical purpose. They can be used at home to detect viral antigens which, according to the Centre for Disease Control, indicate the presence of a viral infection.
Administering a test is as simple as collecting a sample from inside the nose and/or throat, and applying it to a test strip. In 15 minutes, the test strip will change color in a way that denotes a positive or negative test result. According to the American Society for Microbiology, antigen tests are generally considered very accurate when they are positive, and can be a useful tool to prevent super-spreader events or outbreaks.3
When to Take a Rapid Antigen Test
Rapid antigen tests are typically easy to find, depending on your location. Most pharmacies have them in stock, and you can usually get them delivered to your doorstep in a day or two. Everyone is encouraged to have some on hand and to use them as often as is necessary.
When is it necessary, though? For starters, rapid antigen tests should be administered to anyone that feels ill. The Centers for Disease Control highlights fever, chills, muscle or body aches, sore throat, headache, congestion, and diarrhea among their list of symptoms to watch out for.4
Tests are also helpful in the event of a close contact. If you or someone in your household has recently come into contact with someone symptomatic, the CDC suggests administering the test at least 5 days after the date of exposure. A negative test should be followed up with another test roughly 24 to 48-hours later.
Others love the added piece of mind of taking a rapid test ahead of an indoor gathering. Taking a rapid test a few hours before an in-person event could be used to help prevent asymptomatic spread.
Self-Testing
One big benefit of rapid tests is their ability to be taken anywhere, and administered by anyone. They’re capable of delivering quick results without the need for expensive lab equipment and long processing times. Anyone can get results in 15 minutes, instead of having to wait days for the return of your lab test results.
Getting the most accurate results is a matter of following the provided instructions exactly. It’s important to note that instructions can change depending on the brand of the test. So make a habit to read the instructions carefully each time you administer a test.
When it comes to collecting the best sample, two methods continue to be the most popular and effective. The two methods are commonly called the combined oral and nasal method, and the nasal method.
Combined Oral and Nasal Method
The combined oral and nasal method is used by many to deliver accurate rapid antigen test results.5 To do it, you must first refrain from eating, drinking, chewing gum, smoking, and vaping before collecting the sample. Then, carefully swab your tongue, the inside of your cheeks, and the back of your throat, followed by the inside of each nostril.
When swabbing, take care to rotate the swab a few times on each testing surface. You’ll want to avoid contamination after removing it from the packaging by keeping it off surfaces and not touching the cotton swab end of the testing stick. Failing to do so could result in an inaccurate result.
Nasal Method
The nasal method can be done regardless of the brand of test being used. Before you begin, ensure that your hands are washed thoroughly and you’re using a surface that has been disinfected ahead of time.
Start by removing the swab from its package and tilting your head backwards. Then, gently insert the soft end of the swab into your nose, rotating the swab against the interior walls of the nostril. Remove the swab, and repeat the steps above in your other nostril before placing the swab into the supplied test tube and continuing on with the written instructions.
When Can I Expect the Results?
Antigen tests earned the “rapid” moniker thanks to their ability to deliver near-instantaneous results. To put it in perspective, PCR test results can take a couple of days to deliver results. The CDC says you should expect a properly administered rapid antigen test to produce a result in as little as 15 minutes.
Rapid tests may be able to produce quicker results, but they are less sensitive than their lab-based counterparts. That sensitivity disparity means rapid tests require a larger amount of the virus in order to come back positive.
What Does a Positive Result Mean?
A positive antigen test result confirms a viral infection. It doesn’t matter if the person who has been tested doesn’t have any symptoms either. When a rapid antigen test returns a positive result, it’s time to stay in.
The CDC guidelines call for in-home isolation of at least 5 days. If you share a space with others, isolate yourself from them as best as you can and wear a well-fitting mask when you can’t.6 The next step is informing anyone you came into contact with recently of your positive result.
While in isolation, it’s important to monitor yourself or your sick loved one for signs of serious illness. The CDC lists those as pain or pressure in the chest, confusion, trouble breathing, discolored skin, and an inability to wake or stay awake. If any of those signs appear, seek immediate medical attention.
What Does a Negative Result Mean?
If you’ve followed all of the steps, waited the allotted time, and come back with a negative test, plan to test again. As mentioned earlier, rapid tests aren’t as reliable as PCR tests, and require multiple tests to definitely produce a negative result. So, test one more time 24 to 48 hours after the initial test.
If both tests produce a negative result, and you aren’t symptomatic, you’re free to continue on as planned. Should you test negative but continue to exhibit symptoms, stay home until your symptoms start improving.
How Accurate are the Results?
PCR tests may be the most accurate way to test for a virus, but rapid antigen testing serves a purpose too. Their affordability, portability, and ease of use makes them an essential tool for slowing the spread of infection. Less sick people in the hospitals means less stress on your local emergency rooms.
Knowing the increased risk of false negative results is the key to the proper use of rapid antigen tests. You can trust a positive test result. That much is certain. But, should your test come back negative, know that you should still proceed with caution until you’re able to produce a second negative test result 24 hours from the time of the first test.
