- Swabbing your nose and throat could help detect COVID-19 on rapid tests, some disease experts say.
- To collect a throat sample, stick out your tongue, find your tonsils, and swab back and forth. Swab your throat before your nose!
- Wash your hands and refrain from eating or drinking for 30 minutes before performing the swab.
A throat swab, if done properly, might just be the difference between a "positive" or "negative" on some at-home COVID-19 tests.
Some amateur scientists have noted on social media that their rapid tests only come back positive after sampling both saliva and mucus.
Two small (not-yet-peer-reviewed) studies out of South Africa and the US support their experience. Researchers found that saliva tests were more sensitive to Omicron than nasal swabs, perhaps because the viral load from an Omicron infection peaked in saliva one to two days before it peaked in nasal swabs.
Test manufacturers and US health agencies aren't recommending at-home throat swabs yet. A spokesperson for the Food and Drug Administration told Insider that "the FDA has noted safety concerns regarding self-collection of throat swabs, as they are more complicated than nasal swabs — and if used incorrectly, can cause harm to the patient."
However, disease experts told Insider this week that it seems wise to swab both your nose and throat to increase the odds of detecting COVID-19.
The following diagram offers a step-by-step guide on how to correctly swab your throat.
Before you swab:
- Do not drink, eat, or brush your teeth prior to performing the swab. ("The tests are sensitive to acid, so therefore you shouldn't eat or drink about 30 minutes before you take the sample because if you've had something acid, it may turn false positive," Irene Petersen, an epidemiology professor at University College London, told Insider.)
- Next, always be sure to wash your hands thoroughly before testing.
- Then, stand in front of a mirror, and open wide.
Swabbing:
- Stick out your tongue, so you can see the bridge-like, arched surface that extends across the roof of your throat. The area directly behind that bridge, where your tonsils jut out on either side, is the place we're interested in sampling for virus.
- Sweep across both tonsils, at the top of the very back of the mouth, for several seconds. (Or, sweep the area where the tonsils would be, if you've had them removed.) Avoid touching the tongue, teeth, or the insides of your cheeks with the swab.
- Be gentle, but swab judiciously back and forth across both tonsils firmly, at least four times. Sampling this far back may activate your gag reflex, but it shouldn't hurt you.
Then, proceed with your nose swab as usual. It's very important to swab your throat before your nose, because you don't want to introduce anything that may be stuck in your nose down your throat.
Many UK rapid tests already require a combined throat and nose swab, and the UK Health Security Agency released a useful video showing how a person properly collects both samples.
If your throat swab comes back positive, it's probably accurate
A negative test doesn't always means you're in the clear. If it's early or late in the course of your infection, there may not be enough virus particles for the test to pick up on.
But if the test comes back positive, there's little reason to doubt the results.
"If these rapid antigen tests are positive, there's a very, very low likelihood that that's a false positive," Andy Pekosz, a virologist at the Johns Hopkins Bloomberg School of Public Health, told Insider. "So if you do a test and it's positive, you can be quite sure that you're infected."