New studies on alcohol-based hand sanitizers

There are two new studies on the use of alcohol for hand hygiene. Antimicrobial Agents and Chemotherapy has a study from the University of Virginia in which volunteers had their hands inoculated with rhinovirus followed by hand hygiene. Water alone removed the virus from 12% of study subjects, soap and water was 31% effective, and alcohol was 81-87% effective.

In the second study, just released by BMC Infectious Disease, researchers found that with the use of alcohol foam, the larger the volume applied, the longer it takes to dry. Makes sense. But the investigators found that the volume of alcohol that would dry by 30 seconds was only slightly better than water alone in removing E. coli that had been inoculated onto the hands. So more is better; a little dab won't do ya.