Are Hand Sanitizers Better than Hand Washing for Combating the Common Cold?

According to a new study reported by the ASM, hand sanitizers containing ethanol are much more effective at removing rhinovirus from hands than washing with soap and water. Hand sanitizers containing both ethanol and organic acids significantly reduced recovery of the virus from hands and rhinovirus infection up to 4 hours following use. The researchers of this study, conducted at theUniversity of Virginia School of Medicine with support from the Dial Corporation, detail their findings in the March 2010 issue of the journal Antimicrobial Agents and Chemotherapy.

Rhinovirus causes approximately 30 to 35 percent of common colds in adults, and hand-to-hand and fomite-to- hand contact are the most frequent means of transmission. In the study, researchers compared the effects of hand washing with soap and water to use of an ethanol-based hand sanitizer by contaminating the fingers of healthy volunteers with rhinovirus and then randomly grouping them and administering one of six hand treatments.

The experiments ranged from a control group who had no treatment, several groups who washed their hands for differing amounts of time (some with soap, some without), and several who used different amounts of hand sanitizer. Results showed that the ethanol hand sanitizer removed approximately 80 percent of detectable rhinovirus from hands and was much more effective than any other treatment. Contrastingly, soap and water removed rhinovirus from only 31 percent of hands.

In addition, researchers added organic acids to the ethanol-based sanitizer and analyzed its ability to provide persistent antiviral activity against rhinovirus following use. This combination resulted in a sanitizer that inactivated the virus on hands and prevented infection 2 to 4 hours following application.

According to the researchers, “The ethanol-containing hand disinfectants were significantly more effective than hand washing with water or with soap and water for removal of detectable rhinovirus for the hands in this study.”

Good sanitation of surfaces and hand-washing remains an important barrier to the potential for disease transmission of rhinovirus and other viruses (such as norovirus). The effects of ethanol may result in “drying” and thus “killing” the virus. When facilities are not available for washing and drying hands, hand sanitizers seem to be a good alternative and can add extra prevention for a society on the go.

To learn more about this topic, visit the MSU Center for Water Sciences blog here.

(Joan Rose, PhD, is the Homer Nowlin Chair in Water Research at Michigan State University and a member of the Water Quality and Health Council)