Look, no one wants to think about it. And yet you can't help but think about it when you smell — or emit— a particularly odoriferous fart. Can that fart spread disease?
We found two studies done decades apart that came to two different conclusions. If this were a police procedural show, this is where the musical cue for presenting the evidence would start playing, and it would sound very serious and cool. Like us. Writing about farts.
Farts Cause Disease: The 1968 Outbreak
In August 1968, an outbreak of infections of a particular strain of streptococci — Streptococcus pyogenes to be exact — occurred at Vanderbilt University Hospital in Nashville, Tennessee. The nine patients infected were housed in different wards with different problems, and they were visited by many medical staff during their stays.
But seven of them shared an anesthesiologist. (Cue that cool police procedural show music again.) The staff took oral swabs of the anesthesiologist's skin and throat, but they came back negative. No trace of the streptococci. Since this was the mid-20th century, when penicillin was handed out like candy, the anesthesiologist was given a short course of the antibiotic. Because why not?
But a few months later in November and December, another outbreak of the same strain of strep infected eight different patients. The same anesthesiologist attended five of these new cases. He still wasn't showing any symptoms, but this time the staff took an anal swab of the doctor and that turned up the exact strain of strep effecting these new patients. The anesthesiologist was given a full round of antibiotics and taken off duty for 10 days. Afterward, his cultures were clear of streptococci and there were no further wound infections related to his patients.
Researchers at the time said in The New England Journal of Medicine that while the "anus-to-hand-to-patient rout of transmission" was a possibility, airborne transmission was more likely in this case. The authors of the NEJM paper concluded, then, that it was probably the doctor's farts infecting the patients' wounds, not him washing his hands improperly.
Pants Will Save Your Life: The 2001 Rebuttal
Fast-forward to 2001. A woman called Dr. Karl Kruszelnicki's radio show in Australia asking if she was contaminating the operating room when she quietly farted during procedures. Kruszelnicki thought that was a fair question, so he enlisted a microbiologist friend, Luke Tennant, to help find out.
Tennant asked a colleague to fart into two Petri dishes: once with his pants on and once with his pants down. Never forget, science is very elegant. Tennant checked the dishes the next morning. The no-pants dish had lumps of bacteria similar to those found on our skin and in our gut. The pants dish had no bacteria.
Kruszelnicki noted that the bacteria in the no-pants dish wasn't harmful; it was the same types you'd find in something like probiotic yogurt. Yum.
The Pink Eye Myth
But what about pink eye, you say? You've always heard you can get pink eye if somebody farts on your pillow. First of all, if someone farts on your pillow, they are not your friend and you should kick them to a metaphorical curb at once.
Second, though, the myth just isn't true. It's called "passing gas" because it's gas. Any bacteria in the fart would die pretty quickly outside the body. You can, however, get pink eye from actual poop. If you touch poop and then touch your eye, you can get bacterial conjunctivitis. (This article just gets worse and worse, we know.)
Farts and Viruses
As with a bacterial pink eye infection, any viruses that might be present in your intestines aren't going to spread through farts. This is true even of coronaviruses, like the one that leads to COVID-19. They don't live long without a host, which in this case is your body. Viruses also fall out of the air pretty quickly, meaning the surfaces they land on are more contagious than any fart wafting past your unfortunate nose.
More than anything to do with farts, good hand-washing techniques will make the most difference for keeping bacteria and viruses outside your body. Washing your hands for 20 seconds each time you use the bathroom or touch shared surfaces (the handle of the office refrigerator, for instance) vastly reduces the likelihood that you'll contract any illnesses or infections.
So what have we learned? Wear pants and wash your hands. Words to live by.