Letting Off Steam

In veterinary hospitals, the most common disinfection practice used on hard surfaces is application of chemical disinfectant. Steam and heat are typically used to disinfect instruments and soft surfaces. In this study, the authors investigated the efficacy of a nonindustrial steam cleaner for disinfecting various surfaces in a veterinary hospital. Pre- and posttreatment bacterial count samples were obtained from 5 surface types: concrete dog runs, smooth stainless steel kennel floors, smooth molded stainless steel tubs and sinks, smooth flat plastic laminate surfaces, and rubber mats on scales. Surfaces were treated for 10 seconds with a handheld steam unit. Bacterial organisms of interest were Staphylococcus aureus, Pseudomonas spp, and total coliforms. There were significant reductions in heterotrophic bacterial plate counts when steam was applied to dog runs and dog kennel floors. There was a significant reduction in Pseudomonas spp after steam cleaning of sinks. Although the total number of bacteria was reduced on other surfaces, none were reduced significantly; the rubber mat showed the worst results. Results indicate that steam disinfection could potentially replace or augment chemical disinfection on some but not all hospital surfaces; its use warrants further investigation. Study funded by Advanced Vapor Technologies

Disinfection is important in managing and controlling infections. The most important part of disinfection involves the steps preceding use of a chemical or heat disinfectant (ie, the “hard clean”). The first step is mechanical removal of debris from the surface; the second is a thorough washing with detergent until visibly clean. This cannot be emphasized enough. Disinfectants, chemical- or heat-based, are applied after these 2 steps to kill remaining microbes. In this study, the unit did not disinfect the rubber mat used on the scale. The areas where our patients spend the most amount of time (eg, waiting room, examination room floor, examination room table) need continuous cleaning during the day, often after every patient visit. The reader is encouraged to visit the websites advertising this type of equipment and to keep in mind that a veterinary clinic needs commercial cleaning equipment similar to that at a human hospital.—Karen A. Moriello, DVM, DACVD