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Objectives:To establish an animal model to study transmissible spongiform encephalopathy using hamsters and steel wires contaminated with infectious brain materials as transfer vehicles, and, based on this model, to test decontamination procedures against the infectious prion proteins on the steel wires as a near real situation bioassay.Design:Infectious brain materials were given to healthy hamsters intracerebrally either as a suspension or as dried materials on the surface of steel wires. The animals were observed for 18 months. During this period, animals showing definitive clinical signs were euthanized. Decontamination studies were performed by reprocessing contaminated steel wires with different disinfection agents and procedures before implantation.Results:Pathological prion proteins were able to bind to the steel wires and caused disease after the contaminated wires were implanted in the brains of hamsters. When the contaminated wires were treated with different reprocessing procedures before implantation, infectivity was reduced, which was manifested directly by prolonged survival time of the test animals. These results show that this model can be used as a bioassay to validate reprocessing procedures for surgical instruments.Conclusions:At the time of submission of this article, only the group of hamsters incubated with wires reprocessed with an alkaline detergent, followed by sterilization with a modified cycle in a hydrogen peroxide gas plasma sterilizer (4 injections), showed no clinical signs of disease and remained alive. Two animals from the group receiving sodium hydroxide followed by autoclaving (at 134° C for 18 minutes) died. Furthermore, the tested enzymatic cleaning agent seemed to have no positive effect.

Objective:To determine whether reprocessed single-use devices would meet regulatory standards for sterility and meet the same materials standards as a new device.Design:The study included single-use and reusable biopsy forceps and papillotomes and a reusable stone retrieval basket. The suitability of these devices for cleaning and disinfection or sterilization was examined.Methods:Testing of cleanability was conducted on devices contaminated with technetium 99-radiolabeled human blood. Instruments were cleaned using hospital recommended practices for manual cleaning. Gamma counts per second were determined before and after cleaning to localize contaminants, which were additionally visualized using light and scanning electron microscopy. X-ray phc-toelectron spectroscopy was used to quantify contamination elements on the materials tested. Residual bioburden testing on instruments contaminated with microorganisms suspended in coagulable sheep blood was carried out to establish the efficacy of disinfection and sterilization.Results:All devices remained contaminated after cleaning, but single-use devices and the stone basket tended to be more heavily contaminated than reusable forceps and papillotomes. Cleaning procedures facilitated distribution of contaminants further into the lumens of the disposable forceps. Decreased concentrations of silicon and increased concentrations of carbon and nitrogen suggested that layers of silicon lubricant had been removed and contaminants were organic material. Reusable devices were effectively disinfected, but single-use devices were not Sterilization could not eliminate the challenge microorganisms completely.Conclusions:None of the reprocessed single-use instruments were effectively cleaned, disinfected, or sterilized. This condition may provide an opportunity for the viability of non-resistant or nosocomial organisms and viruses. Additionally, reprocessing procedures may result in material destruction of fragile devices. Cost-saving initiatives that have inspired reprocessing of single-use devices, despite the absence of data establishing the efficacy of decontamination and the durability of materials throughout reprocessing, should be pushed into the background.