Efficacy of common disinfectant/cleaning agents in inactivating murine norovirus and feline calicivirus as surrogate viruses for human norovirus

Background/Objectives: Norovirus, a major cause of foodborne gastrointestinal infection, cannot be propagated in cell culture. Limited information exists on the effectiveness of disinfectants and cleaning agents. The objective of this study was to determine the efficacy of common types of disinfectants/cleaning agents used in health care facilities in British Columbia on surrogate viruses, murine norovirus (MNV-1) and feline calicivirus (FCV). Sodium hypochlorite, accelerated hydrogen peroxide (AHP) and a quaternary ammonium compound (QUAT) were assessed. Methods: A virus suspension of known concentration (with or without a soil load) was deposited onto stainless steel discs under wet or dry load conditions and exposed to defined concentrations of the disinfectant/cleaning agent for 1, 5 or 10 minute contact time using the quantitative carrier test (QCT-2) method. Virus inactivation was determined by plaque assay. Results: Sodium hypochlorite at 1350 ppm inactivated MNV-1 after 5 minutes with a ~5.5 to 6.5 log₁₀ reduction, whereas it took twice as long to inactivate the FCV with ~4.6 to 5.6 log₁₀ reduction. After 5 minutes, 2700 ppm of sodium hypochlorite was able to inactivate MNV-1 and FCV. Accel at 35000 ppm AHP inactivated MNV-1 after 10 minutes with a ~5.6 to 6.5 log₁₀ reduction, whereas at 3500 ppm, FCV was inactivated by a ~5 log₁₀ reduction. CaviCide at 2800 ppm QUAT and Virox 5 at 5000 ppm AHP were unable to inactivate MNV-1. T³6 at 2000 ppm QUAT and 70 % ethanol was effective in inactivating MNV-1 with a >6 log₁₀ reduction after 5 minutes, but only resulted in a