Blog | Friday, July 17, 2015

Removing C. difficile spores from hands

It is well known that hand washing, particularly with soap and water, is critical for preventing the transmission of Clostridium difficile in hospitals. Evidence suggests that the mechanical friction of hand washing is the mechanism behind spore removal. However, is there a way to improve the friction when practicing hand hygiene?

To answer this question, investigators at the University of California, San Francisco reported results of a study that compared C. difficile spore removal after washing with 5 different methods including: (1) negative handwashing control: 30 seconds of rubbing with 5 mL of water and 30 seconds of tap water rinsing; (2) 30 seconds of rubbing with 5 mL of 0.3% triclosan soap and 30 seconds of rinsing; (3) 30 seconds of rubbing with a paste consisting of 15 mL of sand mixed with 15 mL of tap water and 30 seconds of rinsing; (4) 15 seconds of rubbing with 5 mL of a 50% baking soda–50% vegetable oil mix and 15 seconds of rubbing with 5 mL of liquid dish detergent followed by 30 seconds of rinsing; and (5) 60 seconds of rinsing.

Lo and behold, washing with sand and water was superior to both the water rub/rinse (0.36-log reduction in spores) and tricolosan soap (0.50-log reduction).

The authors claim that the sand/water method was well tolerated after a single use, although it's hard to imagine that repeated use would be well tolerated. Still, this study raises many interesting questions. For example, what if we used Lava soap containing pumice, or Brillo pads or what if we placed our hands in a rock polishing machine after seeing patients? All kidding aside, you could imagine high-density soaps that have increased friction without the nasty abrasion. In the meantime, I'm going to keep rubbing my hands on my corduroys.

Reference: D. Isaacson et al. AJIC, May 2015.

Eli N. Perencevich, MD, ACP Member, is an infectious disease physician and epidemiologist in Iowa City, Iowa, who studies methods to halt the spread of resistant bacteria in our hospitals (including novel ways to get everyone to wash their hands). This post originally appeared at the blog Controversies in Hospital Infection Prevention.