Effect of Cage-Wash Temperature on the Removal of Infectious Agents from Caging and the Detection of Infectious Agents on the Filters of Animal Bedding-Disposal Cabinets by PCR Analysis.

Efficient, effective cage decontamination and the detection of infection are important to sustainable biosecurity within animal facilities. This study compared the efficacy of cage washing at 110 and 180 °F on preventing pathogen transmission. Soiled cages from mice infected with mouse parvovirus (MPV) and mouse hepatitis virus (MHV) were washed at 110 or 180 °F or were not washed. Sentinels from washed cages did not seroconvert to either virus, whereas sentinels in unwashed cages seroconverted to both agents. Soiled cages from mice harboring MPV, Helicobacter spp., Mycoplasma pulmonis, Syphacia obvelata, and Myocoptes musculinus were washed at 110 or 180 °F or were not washed. Sentinels from washed cages remained pathogen-free, whereas most sentinels in unwashed cages became infected with MPV and S. obvelata. Therefore washing at 110 or 180 °F is sufficient to decontaminate caging and prevent pathogen transmission. We then assessed whether PCR analysis of debris from the bedding disposal cabinet detected pathogens at the facility level. Samples were collected from the prefilter before and after the disposal of bedding from cages housing mice infected with both MPV and MHV. All samples collected before bedding disposal were negative for parvovirus and MHV, and all samples collected afterward were positive for these agents. Furthermore, all samples obtained from the prefilter before the disposal of bedding from multiply infected mice were pathogen-negative, and all those collected afterward were positive for parvovirus, M. pulmonis, S. obvelata, and Myocoptes musculinus. Therefore the debris on the prefilter of bedding-disposal cabinets is useful for pathogen screening.