Amanda M Wilson1, Kelly A Reynolds2, Lee-Ann Jaykus3, Blanca Escudero-Abarca3, Charles P Gerba4. 1. Department of Community, Environment, and Policy, Mel and Enid Zuckerman College of Public Health, University of Arizona, Tucson, AZ. Electronic address: apfeifer@email.arizona.edu. 2. Department of Community, Environment, and Policy, Mel and Enid Zuckerman College of Public Health, University of Arizona, Tucson, AZ. 3. Department of Food, Bioprocessing, and Nutrition Sciences, North Carolina State University, Raleigh, NC. 4. Department of Community, Environment, and Policy, Mel and Enid Zuckerman College of Public Health, University of Arizona, Tucson, AZ; Department of Soil, Water, and Environmental Science, College of Agriculture and Life Sciences, University of Arizona, Tucson, AZ.
Abstract
BACKGROUND: The purpose of this study was to relate experimentally measured log10 human norovirus reductions for a nonresidual (60% ethanol) and a residual (quaternary ammonium-based) hand sanitizer to infection risk reductions. METHODS: Human norovirus log10 reductions on hands for both sanitizers were experimentally measured using the ASTM International Standard E1838-10 method, with modification. Scenarios included product application to: (1) inoculated fingerpads with 30- and 60-second contact times, and (2) hands followed by inoculation with human norovirus immediately and 4 hours later. Hand sanitizer efficacies were used in a mathematical model estimating norovirus infection risk from a single hand-to-fomite contact under low and high environmental contamination conditions. RESULTS: The largest log10 reductions for the residual and nonresidual hand sanitizers were for a 60-second contact time, reducing infection risk by approximately 99% and 85%, respectively. Four hours after application, the residual hand sanitizer reduced infection risks by 78.5% under high contamination conditions, whereas the nonresidual hand sanitizer offered no reduction. DISCUSSION: Log10 virus and infection risk reductions were consistently greater for the residual hand sanitizer under all scenarios. Further data describing residual hand sanitizer efficacy with additional contamination or tactile events are needed. CONCLUSIONS: Residual antinoroviral hand sanitizers may reduce infection risks for up to 4 hours.
BACKGROUND: The purpose of this study was to relate experimentally measured log10 human norovirus reductions for a nonresidual (60% ethanol) and a residual (quaternary ammonium-based) hand sanitizer to infection risk reductions. METHODS:Human norovirus log10 reductions on hands for both sanitizers were experimentally measured using the ASTM International Standard E1838-10 method, with modification. Scenarios included product application to: (1) inoculated fingerpads with 30- and 60-second contact times, and (2) hands followed by inoculation with human norovirus immediately and 4 hours later. Hand sanitizer efficacies were used in a mathematical model estimating norovirus infection risk from a single hand-to-fomite contact under low and high environmental contamination conditions. RESULTS: The largest log10 reductions for the residual and nonresidual hand sanitizers were for a 60-second contact time, reducing infection risk by approximately 99% and 85%, respectively. Four hours after application, the residual hand sanitizer reduced infection risks by 78.5% under high contamination conditions, whereas the nonresidual hand sanitizer offered no reduction. DISCUSSION: Log10 virus and infection risk reductions were consistently greater for the residual hand sanitizer under all scenarios. Further data describing residual hand sanitizer efficacy with additional contamination or tactile events are needed. CONCLUSIONS: Residual antinoroviral hand sanitizers may reduce infection risks for up to 4 hours.
Authors: Marco-Felipe King; Amanda M Wilson; Mark H Weir; Martín López-García; Jessica Proctor; Waseem Hiwar; Amirul Khan; Louise A Fletcher; P Andrew Sleigh; Ian Clifton; Stephanie J Dancer; Mark Wilcox; Kelly A Reynolds; Catherine J Noakes Journal: Indoor Air Date: 2021-10-24 Impact factor: 6.554