Effectiveness of Consumers Washing with Sanitizers to Reduce Human Norovirus on Mixed Salad

Abstract

Human norovirus (HuNoV) is a foremost cause of domestically acquired foodborne acute gastroenteritis and outbreaks. Despite industrial efforts to control HuNoV contamination of foods, its prevalence in foodstuffs at retail is significant. HuNoV infections are often associated with the consumption of contaminated produce, including ready-to-eat (RTE) salads. Decontamination of produce by washing with disinfectants is a consumer habit which could significantly contribute to mitigate the risk of infection. The aim of our study was to measure the effectiveness of chemical sanitizers in inactivating genogroup I and II HuNoV strains on mixed salads using a propidium monoazide (PMAxx)-viability RTqPCR assay. Addition of sodium hypochlorite, peracetic acid, or chlorine dioxide significantly enhanced viral removal as compared with water alone. Peracetic acid provided the highest effectiveness, with log10 reductions on virus levels of 3.66 ± 0.40 and 3.33 ± 0.19 for genogroup I and II, respectively. Chlorine dioxide showed lower disinfection efficiency. Our results provide information useful to the food industry and final consumers for improving the microbiological safety of fresh products in relation to foodborne viruses.

A systematic review on chlorine dioxide as a disinfectant

“…In general, the studied articles gathered came to the same conclusion that chlorine dioxide is effective against micro-organisms tested [ 10 – 18 , 20 – 23 ]. Not all of the concentrations used in all of the studies were the same; therefore, it is better to evaluate whether or not chlorine had its effect on different types of micro-organisms.…”

“…The articles obtained for this section were published from 1998 to 2019. The most recent article evaluated the effectiveness of chlorine dioxide as a sanitizer on mixed salad to reduce the presence of human norovirus [ 10 ]. The study evaluated the efficacy of a chlorine dioxide solution prepared using 2000 mg/L of chlorine gas dissolved in water.…”

“…The only possible reason for using different concentrations of chlorine dioxide may be based on the guidelines on the micro-organisms tested. As a result, most of the studies that tested the efficacy of chlorine dioxide against viruses used a higher concentration of chlorine dioxide compared to the concentration used for bacteria and fungi [ 10 – 12 , 15 , 17 , 23 ]. For bacteria and fungi, even the lowest possible concentration of chlorine dioxide gives an effect.…”

“…When chlorine dioxide is compared with other disinfectants, it is better to keep in mind that most studies used a lower concentration of chlorine dioxide than other disinfectants [ 10 , 16 , 22 , 23 ]. Even at a low concentration of chlorine dioxide used, it is effective against the tested micro-organisms.…”

“…Even at a low concentration of chlorine dioxide used, it is effective against the tested micro-organisms. Another disinfectant, such as hypochlorite and peracetic acid, was used at a higher concentration which may be 2 to 3 times higher and have a high efficacy [ 10 ]. Therefore, using chlorine dioxide lower than that and still being effective was considered more effective.…”