Current risk of iatrogenic Creutzfeld–Jakob disease in the UK: efficacy of available cleaning chemistries and reusability of neurosurgical instruments
References and further reading may be available for this article. To view references and further reading you must purchase this article.
R. Hervé, aT.J. Seckera and C.W. Keevila
a Environmental Healthcare Unit, School of Biological Sciences, University of Southampton, Southampton, UK
Received 19 January 2010; accepted 27 January 2010. Available online 6 May 2010.
Summary The initial cleaning of reusable surgical devices is critical to ensure the efficacy of the subsequent sterilisation process. Transmissible spongiform encephalopathies (TSEs) are incurable and fatal neurodegenerative diseases apparently transmitted simply by the absorption or ingestion of self-aggregating protease-resistant prions (PrPSc), which are very resilient to most standard cleaning chemistries and heat-based decontamination techniques. Therefore there is a risk of iatrogenic transmission from reusable surgical devices if these are allowed to retain potentially infectious material after standard reprocessing through sterile service departments (SSDs). We aimed to assess the current state of surgical instrument decontamination with the collaboration of anonymous SSDs. Surgical stainless steel surfaces were spiked with prion-infected brain homogenates, and episcopic differential interference contrast/epifluorescence (EDIC/EF) microscopy was applied to quantify the amount of residual prion amyloid and other proteins remaining after decontamination with enzymatic cleaners currently employed by SSDs. Reusable instruments deemed ‘clean and ready to use’ were also stained for comparison with our findings in the laboratory. All cleaning chemistries were only partially effective under the recommended conditions. More importantly, PrPSc constituted the main fraction of the remaining contamination left on these surfaces. The neurosurgery instruments also harboured amyloid and general protein contamination. This study shows that currently marketed cleaning chemistries and recent decontamination protocols do not completely suppress the threat from iatrogenic CJD. These findings should be taken into account for risk assessment purposes and re-evaluating instrument handling and decontamination practices.
Article Outline Introduction Methods Preparation of contaminated surfaces Decontamination of surfaces and staining Microscopy and image analysis Statistical analysis Results Enzymatic cleaners State of neurosurgical instruments Discussion Acknowledgements Conflict of interest statement Funding sources References
New studies on the heat resistance of hamster-adapted scrapie agent: Threshold survival after ashing at 600°C suggests an inorganic template of replication
Exposure to 600°C completely ashed the brain samples, which, when reconstituted with saline to their original weights, transmitted disease to 5 of 35 inoculated hamsters. No transmissions occurred after exposure to 1,000°C. These results suggest that an inorganic molecular template with a decomposition point near 600°C is capable of nucleating the biological replication of the scrapie agent.
In addition to brain homogenates, we performed bioassays using irradiated faecal homogenates collected from infected mule deer by intracerebral inoculation into Tg(ElkPrP) mice. Irradiation was used to damage nucleic acids and inactivate bacteria and viruses with minimal effects on prion titres23; irradiation of the Elk1 CWD isolate did not diminish its titre when assayed in Tg(ElkPrP) mice (data not shown).
ASP Sterrad Technology Approved by AFSSAPS for Total Inactivation of Prions French Health Products Safety Agency AFSSAPS Approves STERRAD® Hydrogen Peroxide Gas Plasma Technology for Total Inactivation of Protein-based Infectious Agents Linked to Fatal Brain Diseases
Paris, France (April 27, 2010) --
Advanced Sterilization Products (ASP) announced today that the French Health Products Safety Agency, AFSSAPS, will approve the low-temperature hydrogen peroxide gas plasma STERRAD® NX™ and the STERRAD® 100NX™ Sterilization Systems for total inactivation of prions.
Prions, which are protein-based infectious agents, cause neurodegenerative brain diseases characterized by the formation of "holes" in brain tissue. Prions are highly resistant to the commonly used procedures for inactivating them, and until recently, only the most severe sterilization processes had been proven effective.
"The effectiveness of low-temperature STERRAD® technology against the prion threat confirmed that is possible to eliminate these deadly pathogens while helping to preserve the integrity of medical devices, including heat sensitive surgical instruments," said Dr. Pascal Clayette, SPI-BIO, CEA, Fontenay-aux-Roses, France. "This is a great milestone for healthcare facilities who use an increasing number of sophisticated and costly surgical instruments and for patients who demand the most stringent infection prevention practices."
Following a number of in vivo and in vitro studies conducted on behalf of ASP by two independent laboratories in France and Germany, the STERRAD® NX™ Advanced Cycle and STERRAD® 100NX™ System Flex and Standard Cycles successfully provided prion inactivation and proved to be more effective on the prion threat than steam sterilization at 134degrees C for 18 minutes, which is the steam cycle recommended by the World Health Organization.
"The AFSSAPS approval of STERRAD® System sterilization technology for total inactivation of prions is another example of ASP's commitment to developing innovative infection prevention solutions that help raise the standards of care," said Chuck Austin, WW President of ASP. "STERRAD® Sterilization Systems are used by thousands of healthcare facilities across the globe and this new approval by the French Health Products Safety Agency is a significant benefit for customers and patients alike."
About STERRAD® Sterilization Systems Engineered using ASP's breakthrough low-temperature gas plasma technology, STERRAD® Sterilization Systems terminally sterilize surgical instruments and medical devices safely and effectively, without the limitations or risks associated with peracetic acid, steam, formaldehyde and ethylene oxide gas systems. With thousands of units in use at hospitals and healthcare facilities around the world, STERRAD® Sterilization Systems produce a measurable return on hospital's sterilization investment by reducing instrument repair costs, offering rapid cycles, reducing instrument inventories and enhancing safety.
About Prion Diseases Prion diseases, or proteinaceous infectious particle only agents, are able to induce abnormal folding of normal cellular prion proteins in the brain and can develop into neurodegenerative disorders including Gerstmann-Straussler-Scheinker Syndrome, fatal familial insomnia and Creutzfeldt-Jakob Disease (CJD) in humans. Such prion diseases can have long asymptomatic incubation periods but will result in fatality in all cases. Unlike infectious agents in other difficult-to-treat infectious diseases, prions exhibit an unusually high level of resistance to common sterilization methods and disinfection methods, including steam, and pose a threat to infection prevention in healthcare facilities.
About the Data ASP, through the use of several independent laboratories in France and Germany produced a set of comprehensive studies on prion inactivation. 61 tests (41 in vivo and over 20 in vitro controls) evaluating and comparing disinfection, washing and sterilization procedures were performed. In these studies, the STERRAD® NX™ Advanced Cycle and STERRAD® 100NX™ System Flex and Standard Cycles proved to be more effective in prion inactivation than a steam cycle at 134degreesC, 18 minutes- a special optimized steam cycle recommended by the World Health Organization against prions.
About Advanced Sterilization Products (ASP) Advanced Sterilization Products (ASP), a Division of Ethicon, Inc., a Johnson & Johnson company is a leading developer of innovative instrument sterilization, high level disinfection and cleaning technologies. The company is dedicated to protecting patients, healthcare workers, and the environment with products that focus as much on safety as they do on efficacy and cost-effectiveness. Utilizing advanced instrument processing technologies, these products help customers to promote positive patient outcomes while controlling costs, increasing productivity and enhancing safety. The company is based in Irvine, California with offices around the world.
>>>Advanced Sterilization Products (ASP) announced today that the French Health Products Safety Agency, AFSSAPS, will approve the low-temperature hydrogen peroxide gas plasma STERRAD® NX™ and the STERRAD® 100NX™ Sterilization Systems for total inactivation of prions.<<<
>>>successfully provided prion inactivation and proved to be more effective on the prion threat than steam sterilization at 134degrees C for 18 minutes, which is the steam cycle recommended by the World Health Organization.<<<
hmmm, I would like to see this study of _total_ inactivation of prions.
total inactivation of prions ?
does total _inactivation_ of prions mean _NO_ prions ?
does _more effective_, mean total removal of all prions, i.e. prion free ?
does this total inactivation of prions mean the prion is still there, but not active ?
what does this mean ?
IF the prion is not _removed_, can the inactivated prion become active again ?
how many strains of the prion disease were these total _inactivation_ of the prion conducted on ?
was for instance the L-type atypical BSE tested for total _inactivation_ of the prion disease ? the L-type atypical BSE is much more virulent than the typical c-BSE, so I would hope they tested this atypical BSE, and all the rest of the atypical strains, before going public with a statement of 'total inactivation of prions'.
what about the Nor-98 atypical scrapie, was total _inactivation_ of the prion documented here ?
what about nvCJD and the other 6 documented to date strains of sporadic CJD, all these human TSE showed 100% total inactivation of prions ?
what about second, third, fourth passage of these phenotypes, what about total inactivation of prions ?
NOW, if in fact total inactivation of prions does happen in all these human and animal TSE, both typical strains and atypical strains, why is not every hospital and dental facility around the globe not using this procedure yet ?
Tuesday, March 16, 2010
Transmissible Spongiform Encephalopathy Agents: Safe Working and the Prevention of Infection: Part 4 REVISED FEB. 2010