Virucidal efficacy of disinfectant actives against feline calicivirus, a surrogate for norovirus, in a short contact time

Background: Among other measures, handwashing and targeted disinfection are important in preventing and controlling norovirus outbreaks. Presently, there are a limited number of disinfectants effective against norovirus. There is a need to develop alternatives to bleach that are effective against norovirus, and, in particular, fast-acting disinfectants are desired. The aim of this study was to determine the disinfectant actives and formulation factors necessary to achieve efficacy against norovirus in a short contact time. Methods: Feline calicivirus (FCV) was used as a surrogate for norovirus. In a carrier test method, common disinfectant actives including alcohol, acid, quaternary compound, and phenol both alone and as formulated disinfectants were contacted with dried FCV virus for 1 minute. The virus treatment was neutralized and assayed in Crandell-Reese kidney cells for cytopathic effect. Log(10) virus inactivation was calculated comparing treatment results to virus control titer. Results: Bleach and acid-based disinfectants inactivate FCV in 1 minute. Inactivation of FCV by alcohol and quaternary actives depends on how these actives are formulated as disinfectants. Actives and extreme pH are determined predictive of efficacy. Ethanol and quaternary compounds formulated at appropriate concentration and alkaline pH inactivates FCV in 1-minute contact. Conclusion: Acid cleaners, ethanol, and quaternary compounds formulated at appropriate concentration and pH can be fast-acting antimicrobial choices and alternatives to bleach for the consumer and health care providers to use to inactivate FCV, a surrogate for norovirus, and protect against this important pathogen.