Effect of biocides on murine norovirus and feline calicivirus, surrogates of human norovirus, in suspension, glove and stainless steel disc tests

Human noroviruses (HuNoV) are one of the major agents of human gastroenteritis and transmission occurs mainly by the faecal-oral route.
The purpose of this work was to test biocide products on surrogate viruses of HuNoV in order to get information on the residual viral infectivity and on the integrity of viral genomes after biocide treatment in various conditions.

Murine norovirus (MNN) and feline calicivirus (FCV) have been chosen as HuNoV surrogates because presenting comparable structure and physico-chemical properties.
Two biocide products have been chosen, Ethanol (70%) and Kenocid 2100® (Peracetic acid and hydrogen peroxide) and used in 3 different conditions (in suspension, on gloves and on stainless steel discs).
The biocide product was tested according to Afnor norm EN 14476. The reduction of viral titre was inferred and RNA extraction followed by a 1 step RT-qPCR was performed.

If biocides products tested are able to show a 4 log reduction of the viral infectious titre, they are considered as effective. Efficacy against HuNoV can be extrapolated from these results.
MNV is sensitive to Ethanol and Kenocid 2100® with and without any effect on genomic copy numbers respectively.
FCV is sensitive to Kenocid 2100® with an effect on genomic copy numbers but is resistant to EtOH.
The absence of effect of Kenocid 2100® on genomic copy numbers of MNV indicates this biocide product does not interfere directly on the viral genome. It may likely act on the viral structure, the capsid for example.

This project is financed by Federal Public Service, Health, Food Chain Safety and Environment, in Belgium (RT 10/6 TRAVIFOOD).