Is there a real risk of illness in public restrooms? Yes, mainly by mouth

Is there really a risk in public toilet seats?

If you spend a lot of time outside, human physiology dictates that at some point you have to use a public restroom. And like any shared space, it’s likely to be full of germs. But do community toilets pose public health risks or not?

“There are some health risks associated with public toilets,” said Erica Donner, a professor of environmental science at the University of South Australia. The size of the risk depends on many things, including how often the bathroom is cleaned and whether it’s well ventilated, she explained. But you can also take simple steps to protect yourself, said Donner, co-author of a recent review of studies on infectious disease transmission in public restrooms.

Health officials have tracked the spread of certain disease-causing viruses and bacteria in public restrooms, including norovirus in workplace restrooms, airplanes and cruise ships; salmonella in student dormitory bathrooms; and hepatitis A in elementary school bathrooms. Much research has also documented the presence of pathogenic microbes on toilets and other surfaces in public restrooms, as Donner’s recent article summarized.

Most of these pathogens reach bathroom surfaces through the toilet bowl, because feces and even urine can contain lots of bacteria and viruses, said Charles Gerba, a professor of microbiology at the University of Arizona in the United States.

A toilet flush disperses the tiny microbes in an aerosol plume, which can reach 1.5 m in the air and remain suspended for an hour or more before landing on surrounding surfaces, studies have shown. “All public restrooms are contaminated to some degree just from flushing the toilet,” said Gerba.

But sitting on a contaminated toilet seat and getting a little virus or bacteria on your butt skin won’t necessarily make you sick. Most of these pathogens are not “butt-borne diseases,” as Gerba said.

An exception may be skin infections, particularly those caused by methicillin-resistant Staphylococcus aureus, or SARM, from the English “Selective Androgen Receptor Modulators”., a type of bacteria that is resistant to many antibiotics and therefore difficult to treat.

SARM has been detected in public restrooms and “can be transmitted from the skin to a surface and then to the skin of another person,” Gerba said. It’s not well documented how often this happens, but cleaning a public toilet seat with a disinfectant wipe before using it reduces the risk, he said. (Just be sure to dispose of the tissue in the trash, not the toilet.)

He also agreed with Ina Park, an associate professor of community family medicine at the University of California at San Francisco, who said the risk of MRSA could be “a reason to use a toilet seat cover liner, if any, especially if you have any break in the skin that could come into contact with the toilet seat”.

But “generally the risk is low,” she added. And SARM has been found on many other public surfaces, including ATM keyboards, elevator buttons, locker knobs, and beach sand, as well as on buses and hotel rooms.

Therefore, this risk is not unique to bathrooms.

Toilet seat covers also do not provide foolproof protection. They can be contaminated by aerosol from previous discharges or by occupants of other cabins, Donner said, and are sometimes unavailable.

In that case, is it better to be suspended above the toilet seat to avoid direct contact? “If you have strong muscles, stay suspended, but only if you have good aim,” she said. “You can accidentally create a mess and increase the risk to others.”

More important than wearing a protective liner, sitting up, or standing is how you clean your hands after using the bathroom, Donner said. Thanks to the bathroom feather effect and the use of air hand dryers, which she says can spread germs from wet hands or open garbage cans close to 3 meters, any surface in a public restroom – flush valves, locks cabinets, sink faucets and exit doors, for example – can be contaminated.

And the most common route of infection is “the charmingly so-called ‘fecal-oral route,'” which occurs when pathogens from an infected person’s feces enter their mouth after “touching contaminated surfaces and then touching their face,” Donner explained.

For hand washing to be effective, the Centers for Disease Control and Prevention recommends wetting your hands with clean water, rubbing them with soap for at least 20 seconds, rinsing, and then drying them. But most people don’t wash their hands long enough, and public restrooms often run out of soap and paper towels.

Sometimes it’s also difficult to wash well, like in airplane bathrooms with their tiny sinks and drips of water, and hard not to touch a surface afterwards, Gerba said. After using a public restroom, “the best option is to wash your hands and then use a hand sanitizer when you go out,” he said.

Other tips to remember: If you take a purse or backpack to a public restroom, avoid placing it on the floor, which is one of the dirtiest surfaces in the bathroom, Gerba said. Keep your phone tucked away to avoid contaminating it, and try not to touch surfaces as much as possible, recommends Donner.

Also consider closing the toilet lid before flushing as a public health measure and kindness to others – this step significantly reduces toilet spray.

One thing you don’t have to worry about is getting a sexually transmitted infection in a bathroom, Park said. “I’m not going to say it’s absolutely impossible, but it’s very unlikely,” she said.

Pathogens like gonorrhea and chlamydia don’t survive long on surfaces and must enter the penis or vagina to cause infection, she said. “The place where we sit on the toilet is not the right area.”

Translated by Luiz Roberto M. Gonçalves