I write this blog on the eve of my vacation. Tomorrow, regardless of the fact that I have to get up at an unreasonable hour, I will be sitting in a warm tropical climate by mid-afternoon. This is particularly inviting, since this week has been cold, windy and snowy (-8 to -12 0C / 10 to 17 0F - not including wind chill - and about 10 inches of snow the last couple of days). I am DONE with winter.
In preparation for my trip, I have taken my Dukoral to protect myself against heat-labile producing enterotoxigenic E. coli (I will say, had I realized that sodium hydrogen carbonate powder was part of the vaccine, I may have passed). I have also packed enough hand sanitizer and disinfecting wipes to ensure I am completely covered and have no fear of touching the TV remote in my hotel room! So as I finish the last of my packing and was scrolling through my e-newsletter, I came across a study by researchers at the University of Geneva titled “Assessing the Likelihood of Hand-to-Hand Cross-Transmission of Bacteria: An Experimental Study” that looked at how much E. coli needed to be present on a person’s hands in order to be potentially transmitted to another person, I knew I had to read it.
According to the researchers, only 1 Log10 of viable E. coli cells need to present for transmission. The study used healthcare worker pairs (e.g. a “transmitter” and a host) and increased the amount of E. coli present on the “transmitters” hands. The “transmitter” then held the hand of the “host” for 1 minute. In the end, the study found that hand-to-hand transmission of E. coli was 8.22 times more likely when the viable bacterial count on the “transmitter” hand was >1 Log10. If the viable cell concentration increased to 4 Log10, the Odds Ratio increased to 212.6 times! GROSS!
In doing a bit of “Googling”, the Minnesota State Department of Health has a poster that states there are 1500 bacteria on each square centimeter of your hand. Knowing that 1 Log10 is just a fancy way of saying “approx. 10 bacteria”, then in theory, at any given time it is possible for a person to have enough E. coli on their hands to lead to transmission. Further, according to a 2013 study by Michigan State University, researchers found men were much more likely to just rinse their hands than women after using the restroom. Other research on hand hygiene suggests just 37% of men and 61% of women wash their hands (with soap) after using the restroom.
What does this mean to me? Well, it means that while I “should” be protected from enterotoxigenic E. coli after drinking that nasty Dukoral concoction, there could still be enough pathogenic bacteria on the hands of the housekeeping, wait staff and/or cooks to sink a small ship (aka my vacation). I can’t control everyone, but you can bet I am going to try in earnest to only use female waitresses while on vacation – not because women rule, but at least I have a higher chance that she will have washed her hands after using the restroom, and so “should” have fewer “poop-related” bugs on her hands!