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

Chiu, Stephanie; Skura, Brenton; Petric, Martin; McIntyre, Lorraine; Gamage, Bruce; Isaac-Renton, Judith

BACKGROUND The efficacies of disinfection by sodium hypochlorite, accelerated hydrogen peroxide (AHP), and quaternary ammonium compound (QUAT) commonly used in health care facilities were determined using the surrogate viruses murine norovirus (MNV-1) and feline calicivirus (FCV). 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 At an exposure time of 1 minute, sodium hypochlorite at 2,700 ppm was able to inactivate MNV-1 and FCV with a >5 log10 reduction. After 10 minutes, MNV-1 was inactivated by AHP at 35,000 ppm, whereas FCV was inactivated at 3,500 ppm. MNV-1 was not inactivated by QUAT at 2,800 ppm. A QUAT-alcohol formulation containing 2,000 ppm QUAT and 70% ethanol was effective in inactivating MNV-1 after 5 minutes, but resulted in only a <3 log10 reduction of FCV after 10 minutes. CONCLUSIONS AHP and QUAT products were less effective than sodium hypochlorite for the inactivation of MNV-1 and FCV.