Are your favorite sneakers vectors for COVID-19?

By Claire Gillespie
April 16, 2020
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You might be super vigilant about your laundry right now, as the coronavirus can live on some clothing surfaces. But what about your footwear? A new report from the Centers for Disease Control and Prevention (CDC), published in Emerging Infectious Diseases, suggests that the novel coronavirus can potentially be spread by shoes. 

In the study, researchers took samples from various surfaces at Huoshenshan Hospital in Wuhan, China, the early epicenter of the outbreak—including samples from the soles of ICU staff members' shoes. Half of the samples taken from the shoes tested positive for the virus, leading researchers to suggest that the soles of shoes might function as carriers of the disease.

Epidemiologist Vidya Mony, DO, associate medical director in infection prevention at Santa Clara Valley Medical Center in California, didn't dispute that possibility. “Your feet are not known to be the cleanest part of your body," Dr. Mony tells Health. "Furthermore, the shoes you put on your feet are not known to be clean either. Many shoes are made of material that allows infectious pathogens to breed.” 

Dr. Mony adds that infectious droplets don’t necessarily have a predilection for one part of the shoe, but since the sole is in direct contact with the ground, it has the capability to be the dirtiest. “However, there is a good chance that those can spread to the tops and sides of your shoes as well,” she says. 

Dr. Mony did point out, however, that the CDC study has some limitations. First, researchers used molecular testing—which involves taking a very small sample of RNA and amplifying it to a large enough amount to study in detail—to detect the virus. “From this, we don’t know if the virus was alive or dead; it just shows that the viral particles are present,” she explains.

Also, the study doesn’t state how much virus is needed to cause an infection. “Just because they found the virus on inanimate objects, it doesn’t mean infection,” says Dr. Mony. 

Shoes made of some materials might pose a greater threat than others. According to a study published in The New England Journal of Medicine on March 17, the coronavirus can remain active (in other words, capable of causing an infection) on some surfaces, including plastic, for up to three days. This suggests that shoes made of plastic could retain the active virus for that length of time, as opposed to shoes made of natural fibers. 

“We suspect the droplets may dry out faster on natural fibers, like cotton or bamboo,” public health expert Carol A. Winner, MPH, who has directed several federally funded community health-based initiatives, tells Health. “But it’s important to point out that we still don’t know to what extent droplets are likely to reach the shoe level.” 

The CDC researchers recommend that anyone who walks in a COVID-19 hospital ward should disinfect the soles of their shoes before leaving. But what about everybody else? What steps should we be taking to ensure our shoes don’t carry the virus from one place to another, or track it from outdoors into our homes? 

Winner says leaving shoes in your garage, mudroom, or any other space away from the living area is good practice, particularly when you have small children or immunocompromised family members at risk of infection. “Take your shoes off as soon as you get home from taking a walk or going to the store,” she says. “And leave them in this separate, designated area.” Leaving shoes outside is another option, but Winner says that warm, dry air will inactivate the virus fastest. Wherever you leave your shoes, be sure to back out of them so you don’t step into their footprint and contaminate your socks.  

The new coronavirus can also be inactivated (meaning it can’t attach to and enter the target human cell to replicate, which is what leads to infection) by heat or cleaning with soap and water or a solution like Clorox. If you can wash your shoes, Winner recommends doing so in warm soapy water. A wipe down with soapy water should be enough to clean synthetic shoes, and you could even use Lysol if they’re made of plastic. (But don’t use Lysol on leather, as it can cause damage.) When you’re done, dispose of the rag in the washer and wash your hands straight away. 

If you’re really concerned about shoes, you could wear washable shoes out in public, then follow the recommended washing instructions as soon as you get home. 

But in the grand scheme of things, Winner doesn’t think shoes should be of paramount concern right now.  “There is no evidence to say that shoes bring the coronavirus into the home,” she says. 

Plus, shoes are on the part of the body that is furthest from the face, and to become infected with the new coronavirus, viral particles have to get into the nose, mouth, or eyes. “By far, the most important preventative measure is to keep your hands away from your face,” advises Winner. “We know that the greatest risk is person to person—not shoe to person—so the best advice is to adhere to the CDC guidelines of six feet of personal distance, plus wearing a face mask in public.”

The information in this story is accurate as of press time. However, as the situation surrounding COVID-19 continues to evolve, it's possible that some data have changed since publication. While Health is trying to keep our stories as up-to-date as possible, we also encourage readers to stay informed on news and recommendations for their own communities by using the CDCWHO, and their local public health department as resources.

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