Are you swabbing correctly? Different methods could lead to different COVID test results
Seeing inconsistent COVID test results? This health expert says it’s because you’re swabbing incorrectly
Have you ever gotten inconsistent COVID test results, when one test result is negative but the next is positive? Dr. Eric Feigl-Ding, a public health epidemiologist and former Harvard professor, says that’s because you may not be swabbing correctly.
One test, many outcomes: In a recent tweet, Dr. Feigl-Ding tweeted a picture of five at-home rapid COVID tests, all from the same brand and the same person. However, there were three different test results, and they seemed to come down to the method of swabbing.
Swabbing correctly for #COVID19? Most are not. @IamKGB tests—— Eric Feigl-Ding (@DrEricDing) September 26, 2022
1) VERY POS—back of throat, cheeks, roof of mouth & both nasopharyngeal w swab held in place for 10s.
2) NEG—outside portion of nostrils
3) NEG—anterior nares/nasal septum
4) FAINT POS—throat & cheeks
5) Repeated #1 pic.twitter.com/HZRZzJUBsc
- The person who did the tests took the same COVID test using four different swabbing methods. First was a deep swab in the throat, cheeks, roof of mouth and both nostrils, which produced a very obvious positive result.
- The second and third tests took swabs from inside and outside of the nostrils, respectively, both producing negative results. Anterior (inside) nasal swabs are the most common method of swabbing for COVID tests.
- The fourth sample swabbed the throat and cheeks, producing a faint positive result, and the fifth sample was a repeat of the first sample, producing the same results.
How does this work? In a follow-up tweet, Dr. Feigl-Ding recommended that when taking a COVID test, individuals should swab the nose and throat for the most accurate results, citing a Nova Scotia Health study.
- The study found that a swab of both the throat and nose detected 88.7% of positive cases, as compared to 64.5% from a nasal or throat swab alone.
⚠️SWAB THROAT + NOSE TOGETHER—“Compared to PCR testing, nasal-only & throat-only swabs each detected 64.5% of cases. By combining both the **nose & throat swab** in 1 test—the swabs were able to detect 88.7% of cases.” ➡️Where is the FDA?🧵— Eric Feigl-Ding (@DrEricDing) January 22, 2022
HT @legalnomads https://t.co/EvxGtkBAtL pic.twitter.com/NZqfdFHljr
Worth noting: Even though the Nova Scotia study, along with Feigl-Ding’s data, show that a nasal and throat swab produce the most accurate results, most rapid tests in the U.S. are only made for nasal swabbing, according to TIME.