Leave the Enemy at the Door

Every mother tells her children to take their shoes off at the door. While this warning was usually meant to prevent kids from tracking dirt or mud into the house, we now know that you could be bringing something much more dangerous into your home on your shoes.

New research has shown the bacterium Clostridium difficile, or C. diff, could be among the microbial visitors brought into your house on your shoes. C. diff commonly resides in the soil and can cause significant intestinal disease in humans. C. diff produces stable forms called spores that can survive on surfaces for up to 90 days. These spores are resistant to drying and cleaning agents. That provides the opportunity to transfer the bacteria to your hands and eventually your mouth.

Treatment with broad spectrum antibiotics can lead to changes or reductions in the populations of normal bacteria in your large intestine, also called your colon. The microbiome in your colon normally prevents bacteria like C. diff from growing.

C. diff infections can damage your colon, leading to watery diarrhea, significant abdominal pain and fever. In 2015, there were more than 500,000 C. diff infections in the U.S., and there are more than 15,000 U.S. deaths each year. The disease is most prevalent in patients who acquire the disease after antibiotic treatment for another infection and people with a compromised immune system, like patients in chemotherapy or the elderly. C. diff can also become resistant to common antibiotics, and these resistant 'superbugs' are a problem, especially in hospitals.

So, how do people get exposed to these bacteria? After exposure to fecal contamination from someone with the disease, healthcare workers can spread the disease on their hands. This explains the common mantra among healthcare workers to 'wash your hands.' People can easily pick up bacteria from direct contact, soil or contaminated surfaces, which increases the risk.

New research has shown that the bottom of your shoes and dust and dirt in your home can be a source of infection. In a recent study at the University of Houston, almost 40 percent of the soles of shoes were found to be positive for C. diff. C. diff is commonly found in soil and easily transfers to the bottom of your shoes. One third of bathroom/toilet samples and 33 percent of dust samples from homes had C. diff in them. Further, almost 20 percent of other home surfaces yielded positive cultures. Because these bacteria can persist for a long time on surfaces, once they are in the house, they are available to be picked up by unknowing hands.

What is the answer to controlling infections? Good hygiene and hand washing are an easy way to prevent infections. This can be a challenge with young children. While C. diff spores are resistant to most cleaning solutions, chlorine bleach is effective at killing them. Mom always used bleach in the bathroom. And she was right, taking your shoes off at the door is a good thing to do.