Effectiveness of Liquid Soap and Hand Sanitizer against Norwalk Virus on Contaminated Hands

The purpose of this study was to screen sodium hypochlorite and ethanol for efficacy against Norwalk virus (NV) and expand the studies to evaluate the efficacy of antibacterial liquid soap and alcohol-based hand sanitiser for the inactivation of NV on human finger pads. Samples were tested by RT-qPCR both with and without a prior RNase treatment. Using the ASTM standard finger pad method and a modification thereof (with rubbing), the investigators observed the greatest reduction in genomic copies of NV cDNA with the antibacterial liquid soap treatment (0.67-1.20 log10 reduction) and water rinse only (0.58-1.38 log10 reduction). The alcohol-based hand sanitiser was relatively ineffective, reducing the genomic copies of NV cDNA by only 0.14-0.34 log10 compared to baseline. Although the concentrations of genomic copies of NV cDNA were consistently lower on finger pad eluates pre-treated with RNase compared to those without prior RNase treatment, these differences were not statistically significant. Despite the promise of alcohol-based sanitisers for the control of pathogen transmission, they may be relatively ineffective against the HuNoV, reinforcing the need to develop and evaluate new products against this important group of viruses. Appl Environ Microbiol. doi:10.1128/AEM.01729-09