Improving alcohol-based hand wipes

The Centers for Disease Control and Prevention’s guidelines for hand hygiene state that alcohol-based hand wipes are not an effective substitute for alcohol-based hand rub or hand washing with an antimicrobial soap and water.

So, researchers at the University of Pittsburgh, in Pennsylvania upped the alcohol content of the wipes.

First, the details.

• The hands of 7 people were inoculated with a suspension of Serratia marcescens or Geobacillus stearothermophilus.
  • S marcescens has a preference for damp conditions and is commonly found growing in bathrooms (especially on tile grout, shower corners, toilet water line, and basin).
  • G stearothermophilus is commonly used as a challenge organism for sterilization validation studies
• They then washed with each of 3 different products
  • 65.9% ethanol hand wipes (Sani-Hands ALC)
  • 62% ethanol gel rub (Purell),
  • Antimicrobial soap containing 0.75% triclosan (Kindest Kare)

And, the results.

• For both bacteria and spore removal, antibacterial soap was more effective vs 65.9% ethanol hand wipes, which was more effective than 62% ethanol hand rub.
• The average  S marcescens log reductions for 65.9% ethanol alcohol wipe, 62% ethanol alcohol rub, and antimicrobial foam soap were 3.4, 2.3, and 4.4, respectively — a significant difference.
• The average G stearothermophilus log reductions for 65.9% ethanol wipe, 62% ethanol rub, and antimicrobial foam soap were 0.5, ?0.8 increase over baseline, and 1.7, respectively — a significant difference.
  • A log reduction is a measure of how effective the germicide is against the test organism.
  • The log-reduction terminology was developed to express levels of decreased biological contamination in water by factors of 10 that is easily converted to percent reduction.

The bottom line?

You’re still better off using antibacterial soap.

However, the authors concluded, “The alcohol-based hand wipe containing 65.9% ethanol was significantly more effective than the 62% ethanol rub in reducing the number of viable bacteria and spores on the hands.”

11/28/10 18:14 JR