Nosocomial spread of viral infection contributes to increased disease and veterinary costs. Although enveloped viruses are efficiently inactivated by disinfectants, such as detergents and quaternary ammonium compounds (QACs), nonenveloped viruses, such as parvovirus, are more resistant. This study investigated the efficacy of four disinfectants: chlorine dioxide (Dentagen, Oxyfresh Worldwide, Inc, Spokane, WA), potassium peroxymonosulfate (Trifectant, Antec International Ltd)*, a QAC (A33, Airkem Professional Products, St. Paul, MN), and a citricide (Nutribiotic, Nutribiotic Co, Lakeport, CA). Tap water and sodium hypochlorite (3%) were used as negative and positive controls. Feline herpesvirus, feline calicivirus, and feline parvovirus were used because they are graded in their resistance to disinfectants (from susceptible to highly resistant, respectively).
Solutions of disinfectants were prepared by dilution with tap water to twice the manufacturer's recommended concentration. The citricide was prepared according to the manufacturer's instructions for use as an all-purpose cleaner. Each disinfectant dilution was mixed with an equal amount of virus stock, resulting in the recommended concentration of each disinfectant. The mixtures were held at room temperature for 10 minutes and then transferred into dialysis solution. Dialysis was done for 48 hours to eliminate toxic effects of the disinfectants on the cell culture used for virus titration. The preparation was also filtered to remove any bacteria.