We who live in the USA are seldom asked to remove our shoes at the front door when we come to visit.
Ezequiel Minaya of the Wall Street Journal (WSJ) reviewed this subject and took a look at the logic behind this custom, which is far more common in Japan and Finland than in most countries in Europe or North America. According to some research there may be more to this behavior than just being polite and following local tradition. It may actually make sense from a hygienic point of view.
Not surprisingly, it turns out that shoes are the home to all sorts of bugs, including potentially dangerous bacteria. Dr. Kevin W. Garey, from the University of Houston says that bacteria can persists on our shoes for years.
Just think of all the places that you have stepped in the last few days. When you walk into your house wearing those shoes, you are tracking in a menagerie of bacteria that can cause all kinds of illness including diarrhea, meningitis, and urinary tract infections. So why not just take your shoes off at the door?
The welcome mat is certainly no germ barrier. The rubbing of feet on the mat removes dirt, not bacteria. In fact, the rubbing of our shoes on the mat might even be spreading germs from one person’s shoes to others’. It is certainly not killing them. So what does the research show?
Clostridium difficile is a nasty, hard to kill bacteria that can be the cause of a potentially fatal diarrhea. Dr. Garey investigated 30 homes in the Houston area to see if this strain of bacteria could be found on household surfaces. It was. The soles of shoes were its favorite home. C diff. was found there almost 40% of the time. Here is the abstract.
The WSJ reposted that in 2015, researchers from Austria found that more than 40% of shoes grew out the pathogen Listeria monocytogenes and in 2014, a German study found more than a quarter of farm boots carried E.coli.
There is a reason that we don’t wear street shoes in operating rooms as this article explains.
After hematopoietic stem cell transplants, shoe covers are often provided at the door to the patient’s hospital room.
We asked all visitors to our house in the first months after my transplant for CLL to both wear a mask and to take off their shoes.
Therein lies an important point.
The risk is highest for those whose immunity is most weakened. For healthy folks, the risks are small. The presence of bacteria does not mean that there is a real problem. The only way to find that out for sure is to conduct a study comparing infection rates for comparable home where everyone leaves their shoes at the door and those where they don’t. That study, to my knowledge, has never been done.
While not as high-risk as are those who are immediately post transplant, all of us with CLL are somewhat immune-compromised, even early in the disease and even before any therapy.
So why not save on cleaning our floors and ask all who venture into our homes to remove their shoes?
They may even feel more like part of the family.
Brian Koffman, MD 4/11/17
