Purpose: Here, the PGM-MB assay was used to evaluate the ability of common sanitizers to inactivate human Norovirus (HuNoV) within 10% stool filtrate.
Methods: Treatments for one min with free chlorine at concentrations of 33 and 189 ppm, for five min with 5% trisodium phosphate (pH 12), for up to 1h with 350 ppm chlorine dioxide dissolved in water, for 1 min treatments with up to 195 ppm PAA, and for up to 60 min with hydrogen peroxide (4%) were performed followed by the PGM-MB binding assay.
Results: Chlorine treatments reduced virus binding in the PGM-MB assay by 1.48 and 4.14 log, respectively, suggesting that chlorine is an efficient sanitizer for HuNoV. Trisodium phosphate (pH 12) reduced HuNoV binding by 1.6 log, suggesting that TSP, or some other high pH buffer, could be used to treat food and food contact surfaces to reduce HuNoV. One min treatments with 350 ppm chlorine dioxide dissolved in water did not reduce PGM-MB binding, suggesting that the sanitizer may not be suitable for HuNoV inactivation in liquid form. However a 60 min treatment with 350 ppm chlorine dioxide did reduce human norovirus by 2.8 log, indicating that chlorine dioxide had some activity against HuNoV. Peroxyacetic acid (PAA) had limited effectiveness against HuNoV, since HuNoV binding was reduced by less than 1 log. Hydrogen peroxide treatment resulted in minimal binding reduction (0.1 log) suggesting that hydrogen peroxide is not a good liquid sanitizer for HuNoV.
Significance: Overall this study suggests that HuNoV is remarkably resistant to several commonly used disinfectants and advocates for the use of chlorine (sodium hypochlorite) as a HuNoV disinfectant wherever possible.