As the holiday season approaches, Americans preparing to travel hundreds of miles to see family or friends may notice a green mile marker off in the distance: Public restrooms are ahead.

Using shared bathrooms at gas stations, train stations, rest stops and restaurants during long road trips is inevitable. But restrooms are typically small, poorly ventilated spaces — the exact type of environment public health experts say Americans should avoid to reduce the transmission of the novel coronavirus.

The Washington Post has received dozens of questions from readers about ways to mitigate risks while using public restrooms during the pandemic, especially as states start to reopen and people begin to travel again. In the before times, public restrooms were already seen as tiled dens for germs. Now, we’re wearing masks, avoiding crowds and packing hand sanitizer wherever we go. The Post spoke with infectious-disease experts and epidemiologists about what you should consider when entering a public bathroom.

Here’s what you need to know:

— The virus is most likely to travel person to person via respiratory droplets.

— Put on a mask before entering any shared restroom.

— Avoid crowds, and try to make it a quick trip.

— Wash your hands with soap and water before leaving the restroom. Bring hand sanitizer as a backup plan.

Bathrooms first made a splash in June when scientists illustrated how a toilet flush can send a plume of aerosolized droplets up to three feet in the air — almost like a human sneeze, said Chuck Gerba, an environmental microbiologist and professor at the University of Arizona.

Traces of viral RNA from the novel coronavirus have regularly been found in the feces and urine of covid-19 patients. But evidence of the virus’s genetic material doesn’t mean the virus is still infectious. The Centers for Disease Control and Prevention reports it is “unclear whether the virus found in feces may be capable of causing covid-19.”

Scientists have successfully isolated the virus from urine in laboratory settings. But other research suggests that the coronavirus is far less likely to be transmittable person to person after traveling through the human body, and specifically the colon.

Emily Sickbert-Bennett, the director of infection prevention at UNC Medical Center, told The Post that regardless of how the virus may be transmitted — either through aerosolization or via surface contamination — preventive measures remain the same: Wear a mask and practice good hand hygiene.

“Whether or not there’s infectious virus present in the environment, if your nose and mouth are covered with a mask, you are limiting your intake,” Sickbert-Bennett said over the phone.

Based on all available evidence, Sickbert-Bennett said coming in contact with other people — not bathrooms stalls — poses the “greatest risk.” The virus commonly spreads through respiratory droplets when people talk, yell, cough or even sing near each other. If it passed easily through human waste, Sickbert-Bennett told The Post that researchers would probably see far more evidence when conducting contact tracing during outbreaks. Instead, there are far more examples of the virus spreading through close contact and conversations.

When asked for their advice, every expert who spoke to The Post belabored the same point: Wash your hands with soap and water for at least 20 seconds before leaving the bathroom. Soap — in both bar and liquid form — breaks down the membrane of the novel coronavirus when used with water, which is why washing your hands regularly has become such a cornerstone of public health messaging in this pandemic.

Be sure to bring a bottle of hand sanitizer in case the restroom doesn’t have soap or a working faucet. The CDC recommends using a hand sanitizer that contains at least 60 percent alcohol.

“The important breaks in that transmission chain are really preventing any inoculation of your nose and mouth by wearing a mask and washing your hands,” Sickbert-Bennett said.

John Ross, an internal medicine physician at Brigham and Women’s Hospital and an assistant professor at Harvard Medical School, said public health experts have plenty of evidence to suggest that bars and restaurants are “dangerous settings” to contract the virus and “little evidence” that public bathrooms carry the same risk. Sickbert-Bennett said there are more potential sources of risk in a restaurant than a public restroom.

“Public restrooms can be contaminated, … but you’re spending shorter amounts of time in there, doing good hand hygiene,” Sickbert-Bennett said.

Ross said some people’s understanding of risk is not very precise. Public bathrooms are inherently seen as unsanitary places to contract a virus while going out to dinner may seem harmless and fun.

“The idea that stool is yucky, and you should avoid it, and it’s nasty, it can spread diseases. I think it’s fairly intuitive to people,” Ross said. “But the idea of respiratory secretions is maybe not as easy to accept.”

With all this in mind, Gerba said it’s better to use a public restroom that has a fan, open window or some other type of ventilation. Any steady airflow can help remove smaller virus particles.

“As long as they’re properly cleaned and maintained, you’re okay,” Gerba added.

Most people try to keep bathroom trips short and, in this case, that urgency helps. Public health messaging often focuses on indoor versus outdoor spaces, but it’s important to consider the amount of time you spend around others, too. So, maybe leave your phone or book in the car.

“You probably don’t want to be sitting down and reading ‘War and Peace,’ ” Ross told The Post.

This article has been updated to include that John Ross is also an internal medicine physician at Brigham and Women’s Hospital.

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