Hydrogen Peroxide Vapor Decontamination in a Patient Room Using Feline Calicivirus and Murine Norovirus as Surrogate Markers for Human Norovirus.

OBJECTIVE: To determine whether hydrogen peroxide vapor (HPV) could be used to decontaminate caliciviruses from surfaces in a patient room.

DESIGN: Feline calicivirus (FCV) and murine norovirus (MNV) were used as surrogate viability markers to mimic the noncultivable human norovirus. Cell culture supernatants of FCV and MNV were dried in triplicate 35-mm wells of 6-well plastic plates. These plates were placed in various positions in a nonoccupied patient room that was subsequently exposed to HPV. Control plates were positioned in a similar room but were never exposed to HPV.

METHODS: Virucidal activity was measured in cell culture by reduction in 50% tissue culture infective dose titer for FCV and by both 50% tissue culture infective dose titer and plaque reduction for MNV.

RESULTS: Neither viable FCV nor viable MNV could be detected in the test room after HPV treatment. At least 3.65 log reduction for FCV and at least 3.67 log reduction for MNV were found by 50% tissue culture infective dose. With plaque assay, measurable reduction for MNV was at least 2.85 log units.

CONCLUSIONS: The successful inactivation of both surrogate viruses indicates that HPV could be a useful tool for surface decontamination of a patient room contaminated by norovirus. Hence nosocomial spread to subsequent patients can be avoided.