Everyone has probably done it hundreds of times, especially lately — rubbed hands with sanitizer, scrubbed kitchen counters with antibacterial wipes, patted down a toilet-seat cover in a public restroom and used feet, elbows or shoulders to try to open the bathroom door — all in the name of keeping those nasty, scary, invisible germs away.
But what if all of this careful cleaning is an exercise in futility? Is it even possible to keep germs away?
Not really, said Emily Sickbert-Bennett, director of the University of North Carolina (UNC) Medical Center's Infection Prevention program and associate professor of epidemiology and infectious diseases at the UNC School of Medicine.
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"There are more bacteria in and on our bodies than cells," Sickbert-Bennett told Live Science. There are lots of bacteria that naturally occur all over, in water and soil and on other animals, she added.
But these microbes aren't all bad, she said. In fact, most of them are innocuous unless they wind up in the wrong place — like the staphylococcus bacteria that live harmlessly in a person's nose but can be deadly in the bloodstream.
Other microbes are constantly pathogenic, meaning they are always a disease risk. The virus that causes COVID-19 is one of these, Sickbert-Bennett said. These more problematic microbes are likely what most people are worried about when they're trying to get rid of "germs."
So, is there any hope for keeping our environments clear of these microscopic bad guys?
Sickbert-Bennett said the better question to ask is not how to keep surfaces germ-free, but how to stop the germs found in our environments from causing infections.
"Surfaces can be disinfected with everyday household wipes or sprays, and that certainly eliminates the microbes that are found on those surfaces," she said, but those surfaces tend to become continuously recontaminated. Any time two surfaces interact, like a door knob and a finger, microbes are swapped. Plus, microbes in the air can quickly resettle on surfaces that were just disinfected.
"The most important thing is really thinking about the 'chain of infection,'" Sickbert-Bennett said — the small steps that have to happen for a microbe like a virus to infect someone. "Where are the points along that chain where you can interrupt it?" she asked.
In other words, though some harmful microbes might get into your home or onto your skin, the point is to make sure they don't get to a place where they can cause an infection. The COVID-19 bugs, for example, need to be transferred while intact into a person's respiratory system or eyes, so by washing hands before touching the nose, mouth or eyes — the chain of transmission for COVID-19 is broken.
So think about keeping E. Coli out of the gut by cooking food appropriately, and try to keep adenovirus — a common pink eye culprit — out of the eye by washing your hands and not touching your eyes. But otherwise don't stress too much about the world of microbes humans live in. The majority of these germs have their purpose and don't pose a risk to human health. And in fact, many microbes actually help animals thrive and survive, according to studies examining germ-free mice, Helen Vuong, a postdoctoral scholar of Integrative Biology and Physiology at the University of California, Los Angeles wrote in The Conversation.
"Even within our bodies there are a lot of good bacteria that are helping to outcompete the more pathogenic ones and keep us healthy," Sickbert-Bennett said.
Originally published on Live Science.
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Kelly is a writer, producer and Westerner who got her professional start as a whale biologist in New England. She has undergraduate degrees in English literature and ecology and evolutionary biology, and she holds master's degrees in science journalism and creative writing. Meanwhile, she makes wicked good nachos and wears cowboy boots.