Can You Actually Get an Eye Infection from a COVID-19 Test?
Coronavirus tests are notoriously uncomfortable. After all, sticking a long nasal swab deep into your nose isn't exactly a pleasant experience. But coronavirus tests play a huge role in limiting the spread of COVID-19, and ultimately, the tests themselves are harmless — at least, for most people, they are.
ICYMI, Hilary Duff recently shared on her Instagram Stories that she suffered an eye infection over the holidays "from all the COVID tests at work." In a recap of her holiday celebration, Duff said the issue began when one of her eyes "started to look weird" and "hurt a lot." The pain eventually grew to be so intense that Duff said she "took a little trip to the emergency room," where she was given antibiotics.
The good news is, Duff confirmed in a later IG Story that the antibiotics worked their magic and her eye is totally fine now.
Still, you're probably wondering whether eye infections from COVID tests are actually a thing you need to worry about. Here's what you need to know.
First, a recap on COVID-19 testing basics.
Generally speaking, there are two main types of diagnostic tests for SARS-CoV-2, the virus that causes COVID-19. The Food and Drug Administration (FDA) breaks down the tests this way:
- PCR test: Also called a molecular test, this test looks for genetic material from SARS-CoV-2. Most PCR tests are done by taking a patient's sample and shipping it to a lab for analysis.
- Antigen test: Also known as rapid tests, antigen tests detect specific proteins from SARS-CoV-2. They're authorized for point of care and can be done in a doctor's office, hospital, or testing facility.
A PCR test is usually collected with a nasopharyngeal swab, which uses a long, thin, Q-tip-like tool to take a sample of cells from the very back of your nasal passages. PCR tests can also be done with a nasal swab, which is similar to a nasopharyngeal swab but doesn't go back as far. While not as common, PCR tests can also be collected via nasal wash or saliva sample, depending on the test, according to the FDA. But an antigen test is always taken with a nasopharyngeal or nasal swab. (More here: Everything You Need to Know About Coronavirus Testing)
So, can you get an eye infection from a COVID test?
The short answer: It's pretty unlikely. The Centers for Disease Control and Prevention (CDC) makes no mention of the risk of developing an eye infection after having any type of COVID-19 test.
What's more, research has found that the nasopharyngeal swabs used to carry out most COVID-19 tests are considered a generally safe method of testing. One study of 3,083 people who were given swab tests for COVID-19 found that just 0.026 percent experienced some kind of "adverse event," which largely included the (very rare) occurrence of a swab breaking inside a person's nose. There was no mention of eye issues in the study.
Another study that compared the effects of commercial and 3D-printed swabs found that there were only "minor adverse effects" associated with either type of test. Those effects included nasal discomfort, headache, earache, and rhinorrhea (i.e. runny nose). Again, no mention of eye infections.
How could someone possibly get an eye infection from a COVID test?
Duff didn't offer an explanation in her posts, but Vivian Shibayama, O.D., an optometrist at UCLA Health, shares an interesting theory: "Your nasal cavity is connected to your eyes. So if you had a respiratory infection, it could travel into your eyes." (Related: Is Wearing Contacts During the Coronavirus Pandemic a Bad Idea?)
But Duff didn't say she had a respiratory infection at the time she was tested; rather, she said the eye infection was a result of "all the COVID tests" she's had lately in her work as an actress. (She also recently had to quarantine after being exposed to COVID-19.)
Plus, Duff said she was able to treat the eye infection with antibiotics — a detail that suggests she had a bacterial, rather than viral infection, notes Aaron Zimmerman, O.D., a professor of clinical optometry at The Ohio State University College of Optometry. (FTR, respiratory infections can be bacterial, but they're usually viral, according to Duke Health.)
"The only way [you could get an eye infection from a COVID test] would be if the swab was contaminated prior to being applied," says Zimmerman. If a contaminated swab was applied to your nasopharynx (i.e. the very back of your nasal passages), in theory, traces of bacteria or a virus "could migrate to the ocular surface as the eyes drain into your nasopharynx and ultimately your throat," he explains. But, adds Zimmerman, this is "extremely unlikely."
"With COVID testing, the swabs should be sterile, so the risk of [eye] infection should be slim to none," says Shibayama. "The person giving the test should be gloved and masked with a face shield," she adds, meaning any possible person-to-person transmission of an eye infection "should also be low." (Related: Everything You Need to Know About Coronavirus Transmission)
That's true regardless of what type of testing you undergo, and repeat COVID-19 testing shouldn't make a difference, either. "There are plenty of people who get tested all the time with no issues," says infectious disease expert Amesh A. Adalja, M.D., senior scholar at the Johns Hopkins Center for Health Security. "NBA and NHL players were tested daily during their seasons and there were no reports of eye infections as a result."
Bottom line: "There is no evidence of biologic plausibility that getting a COVID test could give you an eye infection," says Thomas Russo, M.D., a professor and chief of infectious disease at the University at Buffalo.
With that in mind, Dr. Adalja warns against taking too much from Duff's experience. In other words, it definitely shouldn't dissuade you from getting a COVID-19 test if and when you need one. "If you need to get tested for COVID-19, get tested," says Dr. Adalja.
The information in this story is accurate as of press time. As updates about coronavirus COVID-19 continue to evolve, it’s possible that some information and recommendations in this story have changed since initial publication. We encourage you to check in regularly with resources such as the CDC, the WHO, and your local public health department for the most up-to-date data and recommendations.