Impact of disinfectant-filled foot mats on mechanical transmission of bacteria in a veterinary teaching hospital.

OBJECTIVE To evaluate the efficacy of disinfectant-filled foot mats at reducing tracking of Salmonella enterica and overall bacterial contamination on floors in a veterinary teaching hospital. DESIGN Prospective study. Samples-Bacteria collected from floors before and after placement of disinfectant-filled foot mats. PROCEDURES Foot mats filled with a phenolic-based disinfectant were placed at key transition areas in common-use corridors between the large animal hospital (LAH) and small animal hospital in a veterinary medical teaching hospital. Microbiological samples were collected for total bacterial counts and for the presence of S enterica at 14 designated sample sites in the veterinary medical teaching hospital. Samples were collected at regular intervals for 7 months before mat placement and for 13 months after mat placement. RESULTS Median numbers of aerobic bacteria isolated before and after disinfectant mat placement were not significantly different for most sites sampled. For 3 of the 4 transition areas between the LAH and connecting common-use corridor, there was a significant difference in median bacterial counts on either side of the threshold. This difference was significant regardless of whether a disinfectant mat was present or not. Salmonella enterica isolates were cultured from several sites in the LAH and sites outside the LAH, irrespective of the presence of a disinfectant mat. CONCLUSIONS AND CLINICAL RELEVANCE -Disinfectant-filled mats may not be uniformly effective in reducing the bacterial load on floors or in reducing mechanical tracking of S enterica from contaminated areas in a veterinary teaching hospital. Further studies are needed to determine effective measures to reduce mechanical transmission of bacteria on footwear in veterinary hospitals.