Efficacies of Sodium Hypochlorite and Quaternary Ammonium Sanitizers for Reduction of Norovirus and Selected Bacteria during Ware-Washing Operations

Abstract

Cross-contamination of ready-to-eat (RTE) foods with pathogens on contaminated tableware and food preparation utensils is an important factor associated with foodborne illnesses. To prevent this, restaurants and food service establishments are required to achieve a minimum microbial reduction of 5 logs from these surfaces. This study evaluated the sanitization efficacies of ware-washing protocols (manual and mechanical) used in restaurants to clean tableware items. Ceramic plates, drinking glasses and stainless steel forks were used as the food contact surfaces. These were contaminated with cream cheese and reduced-fat milk inoculated with murine norovirus (MNV-1), Escherichia coli K-12 and Listeria innocua. The sanitizing solutions tested were sodium hypochlorite (chlorine), quaternary ammonium (QAC) and tap water (control). During the study, the survivability and response to the experimental conditions of the bacterial species was compared with that of MNV-1. The results showed that current ware-washing protocols used to remove bacteria from tableware items were not sufficient to achieve a 5 log reduction in MNV-1 titer. After washing, a maximum of 3 log reduction in the virus were obtained. It was concluded that MNV-1 appeared to be more resistant to both the washing process and the sanitizers when compared with E. coli K-12 and L. innocua.

Study of the Virucidal Potential of Organic Peroxyacids Against Norovirus on Food-Contact Surfaces

“…Foods with a high risk of norovirus contamination include fresh produce, shellfish, and other products that undergo minimal or no processing (Falkenhorst et al 2005;Gallimore et al 2005;Le Guyader et al 2010). Despite current means of disinfection used to hinder spread via food, water and fomites (Feliciano et al 2012), the prevalence of norovirus infection remains high. This points to problems with the disinfectants used and the way they are used, as well as outbreak management and prevention.…”

Inactivation Kinetics and Mechanism of a Human Norovirus Surrogate on Stainless Steel Coupons via Chlorine Dioxide Gas

“…However, most of these studies were performed by directly mixing viral stock with ClO 2 solution, not by applying the ClO 2 solution to virus dried on surfaces or by adding any organic amendments. A recent study found that chlorine solution can remove/inactivate less than 1 log of MNV-1 from the surface of tableware and food preparation utensils, although it can achieve more than a 5-log reduction of Escherichia coli K-12 and Listeria innocua (24). This result demonstrated that ClO 2 solution may be ineffective against viruses on the food contact surfaces.…”

“…However, in the previously mentioned study, MNV-1 was mixed with a cream cheese or reduced-fat milk food matrix and applied to the utensils (24). It has been established that the presence of organic materials can affect the biocidal activity of ClO 2 solution and, potentially, gaseous ClO 2 .…”

“…However, these sanitizers are not effective in inactivating and removing foodborne viruses from contact surfaces at Environmental Protection Agency (EPA)-and Food and Drug Administration (FDA)-permitted concentrations. Sodium hypochlorite and quaternary ammonium sanitizers achieved only a 0.5-log reduction in MNV-1 titer when tableware and food preparation utensils (plates, drinking glasses, and stainless steel forks) were contaminated with MNV (24). Development of an effective sanitizer for the inactivation of human NoV, therefore, is urgently needed.…”

Epidemiology, Prevention, and Control of the Number One Foodborne Illness

“…13 However, because human NoV cannot be cultivated, the efficacy of this treatment and other disinfectants approved by the US Environmental Protection Agency for human NoV has been established using surrogate viruses. [82][83][84] These surrogate viruses may not accurately represent the disinfection kinetics of human NoV, but they remain the most suitable representation. The CDC recommends increasing cleaning wards to twice daily and contact surfaces to 3 times daily with 1000 to 5000 ppm chlorine or an EPA-approved disinfectant during a human NoV outbreak, to increase the efficacy of decontamination.…”