Improved inactivation of nonenveloped enteric viruses and their surrogates by a novel alcohol-based hand sanitizer

Abstract

Norovirus is the leading cause of food-related illness in the United States, and contamination of ready-to-eat items by food handlers poses a high risk for disease. This study reports the in vitro (suspension test) and in vivo (fingerpad protocol) assessments of a new ethanol-based hand sanitizer containing a synergistic blend of polyquaternium polymer and organic acid, which is active against viruses of public health importance, including norovirus. When tested in suspension, the test product reduced the infectivity of the nonenveloped viruses human rotavirus (HRV), poliovirus type 1 (PV-1), and the human norovirus (HNV) surrogates feline calicivirus (FCV) F-9 and murine norovirus type 1 (MNV-1) by greater than 3 log(10) after a 30-s exposure. In contrast, a benchmark alcohol-based hand sanitizer reduced only HRV by greater than 3 log(10) and none of the additional viruses by greater than 1.2 log(10) after the same exposure. In fingerpad experiments, the test product produced a 2.48 log(10) reduction of MNV-1 after a 30-s exposure, whereas a 75% ethanol control produced a 0.91 log(10) reduction. Additionally, the test product reduced the infectivity titers of adenovirus type 5 (ADV-5) and HRV by > or =3.16 log(10) and > or =4.32 log(10), respectively, by the fingerpad assay within 15 s; and PV-1 was reduced by 2.98 log(10) in 30 s by the same method. Based on these results, we conclude that this new ethanol-based hand sanitizer is a promising option for reducing the transmission of enteric viruses, including norovirus, by food handlers and care providers.

FIG. 1.

Virucidal activity of various alcoholic mixtures as measured by a suspension test against MS2, with a 60-s exposure at room temperature. When they were included, citric acid was at 0.25% (wt/wt), and PQ-37 was at 0.4% (wt/wt). The bar heights indicate the mean values from a minimum of six replicates, and the error bars indicate standard errors of the means. † indicates significantly greater activity than 78% ethanol (EtOH) by one way ANOVA (P < 0.001). ‡ indicates significantly greater activity than all other alcoholic mixtures (P < 0.001).