Researchers Say Proceed with Caution on Efficacy Data Related to Hand Disinfectants

Some national hospital hygiene societies in Europe such as the French society for hospital hygiene (SFHH) have positive lists of disinfectants. Few hand disinfectants with a rather low concentration of ethanol are listed by one society as effective for hygienic hand disinfection with 3 mL in 30 s including a virucidal activity in 30 seconds or 60 seconds, but published data allow having doubts. Kampf , et al. (2013) therefore evaluated the efficacy of three commonly used hand disinfectants according to EN 1500 and EN 14476.
Products 1 and 2 were based on 70% ethanol, while product 3 was based on 60% ethanol and 15% isopropanol (all w/w). They were tested in three laboratories according to EN 1500. Three mL were applied for 30 seconds and compared to the reference treatment of 2 x 3 mL applications of isopropanol 60% (v/v), on hands artificially contaminated with Escherichia coli. Each laboratory used a cross-over design against the reference alcohol with 15 or 20 volunteers. The virucidal activity of the products was evaluated (EN 14476) in one laboratory against adenovirus and poliovirus in different concentrations (80%, 90%, 97%), with different organic loads (none; clean conditions; phosphate-buffered saline) for up to 3 minutes.
Product 1 revealed a mean log10-reduction of 3.87 +/- 0.79 (laboratory 1) and 4.38 +/- 0.87 (laboratory 2) which was significantly lower compared to the reference procedure (4.62 +/- 0.89 and 5.00 +/- 0.87). In laboratory three, product 1 was inferior to the reference disinfection (4.06 +/- 0.86 versus 4.99 +/- 0.90). Product 2 revealed similar results. Product 3 fulfilled the requirements in one laboratory but failed in the two other. None of the three products was able to reduce viral infectivity of both adenovirus and poliovirus by 4 log10 steps in 3 min according to EN 14476.

The researchers conclude that efficacy data mentioned in a positive list published by a society for hospital hygiene should still be regarded with caution if they quite obviously contradict published data on the same or similar products. Their research was published in Antimicrobial Resistance and Infection Control.

Reference: Kampf G, Ostermeyer C, Werner HP and Suchomel M. Efficacy of handrubs with a low alcohol concentration listed as effective by a national hospital hygiene society in Europe. Antimicrobial Resistance and Infection Control 2013, 2:19 doi:10.1186/2047-2994-2-19