Effect of SARS-CoV-2 Incidence and Immunisation Rates on Sporadic Creutzfeldt-Jakob Disease Incidence.

BACKGROUND: Recent case studies and media outlets have hypothesised an effect of SARS-CoV-2 infection and immunisation on the development or progression of neurodegenerative diseases such as Alzheimer's disease or sporadic Creutzfeldt-Jakob disease (sCJD). OBJECTIVES: This study aims to identify potential associations of SARS-CoV-2 infections and SARS-CoV-2 immunisation with sCJD incidence, disease duration, and age of onset. METHOD: We used data from a prospective sCJD surveillance study in Germany (2016-2022) and publicly available datasets of SARS-CoV-2 cases and vaccination numbers in Germany for the years 2020-2022. Associations of SARS-CoV-2 incidence and immunisation rates with sCJD incidence were assessed by comparing quarterly and annual cumulative sCJD incidences in the periods before (2016-2019) and during the pandemic (2020-2022). RESULTS: We could not identify any time-related effect of SARS-CoV-2 incidence or immunisation rate on the sCJD incidence. Moreover, we did not find any sCJD incidence alterations before and during the SARS-CoV-2 pandemic on a federal or state level. The overall sCJD incidence was within expected ranges in the years 2020-2022. There were no changes in age of onset and clinical disease duration in these years. CONCLUSIONS: We found no evidence supporting a short-term effect of the pandemic on sCJD incidence. However, considering the extended pre-clinical phase of sCJD, continued surveillance is needed to identify potential future incidence alterations.

Kinetics of the reduction of Creutzfeldt-Jakob disease prion seeding activity by steam sterilization support the use of validated 134°C programmes.

BACKGROUND: Prions are renowned for their distinct resistance to chemical or physical inactivation, including steam sterilization. Impaired efficacy of inactivation poses a risk to patients for iatrogenic transmission of Creutzfeldt-Jakob disease (CJD) via contaminated surgical instruments. AIMS: Most established prion inactivation methods were validated against scrapie agents, although those were found to be generally less thermostable than human prions. Thus, knowledge gaps regarding steam-sterilization kinetics of CJD prions should be filled and current guidelines reviewed accordingly. METHODS: Prion inactivation through widely recommended steam sterilization at 134°C was assessed for several holding times by analysing the residual prion seeding activity using protein misfolding cyclic amplification (PMCA). FINDINGS: Scrapie 263K was found to be the least thermoresistant prion strain showing no seeding activity after 1.5 min at 134°C, while variant CJD was the most stable one demonstrating some seeding activity even after 18 min of steam sterilization. Sporadic CJD subtype VV2 exhibited residual seeding activity after 3 min, but no detectable activity after 5 min at 134°C. CONCLUSION: Validated steam sterilization for 5 min at 134°C as previously recommended for the routine reprocessing of surgical instruments in contact with high-risk tissues is able to substantially reduce the seeding activity of CJD agents, provided that no fixating chemical disinfection has been performed prior to sterilization and that thorough cleaning has reduced the protein load on the surface to less than 100 µg per instrument.

[Creutzfeldt-Jakob Disease and Lyodura:A Special Reference to Prion Disease Control in the Field of Neurosurgery].

In Japan, 156 cases of dura mater-transplanted Creutzfeldt-Jakob disease(dCJD)with a history of Lyodura transplantation have been confirmed until February 2022, with only a few new cases still being identified. The history of Lyodura transplantation is one involving a neurosurgical procedure. The cumulative global number of cases of bovine spongiform encephalopathy-related variant CJD(BSE-related vCJD), which has shaken societies around the world, is 232 as of 2019. Thus, the impact of dCJD on the society in Japan needs no explanation. Thanks to the world's concerted efforts in research and countermeasures, medically induced prion diseases are finally becoming a thing of the past. However, due to the extremely long incubation period of CJD and the difficulty of tracing the source of infection, immediate action in the event of an outbreak is not possible, and efforts must focus on preventing disease outbreaks. Independent of this, approximately 200 cases of solitary and hereditary prion diseases occur annually in Japan. If neurosurgery must be performed on such patients, secondary transmission of prion disease by neurosurgical instruments must be prevented. Therefore, sterilization methods for neurosurgical instruments are critical, and various measures including sterilization methods have been determined and published by a research group designated by the Japanese Ministry of Health, Labour and Welfare. The sterilization of neurosurgical instruments should comply with the latest guidelines that are published by this study group.

Importation of plasma and use of apheresis platelets as risk reduction measures for variant Creutzfeldt-Jakob disease: The SaBTO review.

Following recognition that blood, blood components, tissues and organs donated by infected donors could transmit infectious prions causing variant Creutzfeldt-Jakob Disease (vCJD), several risk reduction measures were introduced in the UK. The Advisory Committee on the Safety of Blood, Tissues and Organs (SaBTO) established a working group to review the measures in place. Factors considered included: ethical issues around the current provisions and potential changes; operational issues for blood establishments and hospitals; a review from the Advisory Committee on Dangerous Pathogens (ACDP) showing the downward trend in the estimated number of future cases of vCJD; and cost-effectiveness. The working group recommended that the current vCJD risk reduction measures for individuals born after 1995 or with thrombotic thrombocytopenic purpura (TTP) could be withdrawn. After consultation with stakeholders, SaBTO accepted these proposals which allow more equal provision of components, less operational complexity and risk, and more resources to be deployed elsewhere in the NHS. The potential saving on plasma will be £500 m and moving to using pooled platelets in additive solution for all recipients will bring potential savings of £280 m over the next 50 to 60 years. There could be small number of additional clinical cases of vCJD: 1-2 (<1-14; 95% CI) from plasma and 3-4 (<1 to 45; 95% CI) from platelets. Local and national guidelines will still be applied for managing individual conditions. UK Ministers for Health accepted SaBTO's recommendations on 9 Sept 2019 and implementation began immediately. This paper describes the review and rationale leading to these recommendations.

Comparing anti-aging hallmark activities of Metformin and Nano-PSO in a mouse model of genetic Creutzfeldt-Jakob Disease.

Advanced age is the main risk factor for the manifestation of late onset neurodegenerative diseases. Metformin, an anti-diabetic drug, was shown to extend longevity, and to ameliorate the activity of recognized aging hallmarks. Here, we compared the clinical, pathologic and biochemical effects of Metformin to those of Nano-PSO (Granagard), a brain targeted anti-oxidant shown by us to delay disease advance in transgenic mice mimicking for genetic Creutzfeldt Jacob disease (CJD) linked to the E200KPrP mutation. We demonstrate that both Metformin and Nano-PSO reduced aging hallmarks activities such as activated AMPK, the main energy sensor of cells as well as Nrf2 and COX IV1, regulators of oxidation, and mitochondrial activity. Both compounds reduced inflammation and increased stem cells production, however did not decrease PrP accumulation. As opposed to Nano-PSO, Metformin neither delayed clinical disease advance in these mice nor reduced the accumulation of sulfated glycosaminoglycans, a pathologic feature of prion disease. We conclude that elevation of anti-aging markers may not be sufficient to delay the fatal advance of genetic CJD.

The controversial Third Reich history of Hans Creutzfeldt: was he a supporter or just another adept of the "hand washing policy"?

Creutzfeldt-Jakob disease (CJD) is a transmissible spongiform encephalopathy whose initial description is associated with two German authors, Alfons Maria Jakob and Hans Gerhard Creutzfeldt. As polemic as the issue about the Creutzfeldt's merit in the first description of the disease, is his history during the Third Reich. Some evidence pointed to the idea that he was essentially against the Nazi ideology, though some did not. He was an official member of the SS, but his own wife was convicted by a Nazi court. Some authors have argued that Creutzfeldt helped save many patients during Aktion T4 operation, but, in fact, he could have done more. Even during the post-war period, he sent a letter to authorities reporting the name of a Nazi physician who worked as a medical reviewer at the euthanasia court, but he did not proceed any further when his letter initially failed to start an investigation.

Improved surveillance of surgical instruments reprocessing following the variant Creutzfeldt-Jakob disease crisis in England: findings from a three-year survey.

BACKGROUND: Sensitive, direct protein-detection methods are now recommended for the inspection of reprocessed reusable surgical instruments in England to reduce the risk of prion transmission. AIM: To implement an established, highly sensitive method to quantify proteinaceous residues on reprocessed instruments in a Sterile Services Department (SSD) and evaluate its potential impact on service provision. METHODS: We introduced highly sensitive epifluorescence (EDIC/EF) microscopy in a large SSD. Over three years, we periodically tested two models of washer disinfector using stainless-steel tokens spiked with mouse brain homogenate or Browne test soil for comparison. We also obtained data and feedback from staff who had been using EDIC/EF to examine almost 3000 reprocessed instruments. FINDINGS: All reprocessed test surfaces harboured residual contamination (up to 258.4 ng from 1-µg spikes). Proximity between surfaces affected decontamination efficacy and allowed cross-contamination. Up to 50 ng de novo proteinaceous contamination was deposited on control surfaces after a single automated washer disinfector (AWD) cycle. The test soil behaved differently than real tissue contamination. SSD staff observed proteinaceous residues on most reprocessed instruments using EDIC/EF, which can detect far smaller amounts than the currently accepted national threshold of 5 µg per side. CONCLUSIONS: Implementing recent national guidelines to address the prions concern proved an eye-opener. Microscopic levels of proteins remain on many reprocessed instruments. The impact most of these residues, potentially including prions, may have on subsequent patients after sterilization remains debatable. Improving surveillance capability in SSDs can support decision making and raise the standards of surgical instruments reprocessing.

The controversial Third Reich history of Hans Creutzfeldt: was he a supporter or just another adept of the "hand washing policy"? / A controversa história do terceiro reich de Hans Creutzfeldt: seria ele um apoiador ou apenas outro adepto da "política de lavagem das mãos"?

ABSTRACT Creutzfeldt-Jakob disease (CJD) is a transmissible spongiform encephalopathy whose initial description is associated with two German authors, Alfons Maria Jakob and Hans Gerhard Creutzfeldt. As polemic as the issue about the Creutzfeldt's merit in the first description of the disease, is his history during the Third Reich. Some evidence pointed to the idea that he was essentially against the Nazi ideology, though some did not. He was an official member of the SS, but his own wife was convicted by a Nazi court. Some authors have argued that Creutzfeldt helped save many patients during Aktion T4 operation, but, in fact, he could have done more. Even during the post-war period, he sent a letter to authorities reporting the name of a Nazi physician who worked as a medical reviewer at the euthanasia court, but he did not proceed any further when his letter initially failed to start an investigation.

RESUMO A doença de Creutzfeldt-Jakob (DCJ) é uma encefalopatia espongiforme transmissível, cuja descrição original está associada ao nome de dois autores alemães, Alfons Maria Jakob e Hans Gerhard Creuztfeldt. Tão polêmica quanto a questão sobre o real mérito de Creutzfeldt na primeira descrição da doença, é sua história de vida durante o Terceiro Reich. Algumas evidências apontavam para a ideia de que ele era essencialmente contra a ideologia nazista, mas outras não. Ele foi um membro oficial da SS, mas sua própria esposa foi condenada por um tribunal nazista. Alguns autores têm argumentado que Creutzfeldt ajudou a salvar muitos pacientes durante a operação Aktion T4, mas, na verdade, ele poderia ter feito muito mais. Mesmo durante o período pós-guerra, ele enviou uma carta às autoridades revelando o nome de um médico nazista que havia se empregado como revisor médico na corte sobre eutanásia, mas ele não insistiu mais quando sua carta inicialmente não desencadeou uma investigação.

Delay of gCJD aggravation in sick TgMHu2ME199K mice by combining NPC transplantation and Nano-PSO administration.

gCJD is a fatal late-onset neurodegenerative disease linked to mutations in the PRNP gene. We have previously shown that transplantation of neural precursor cells (NPCs), or administration of a nanoformulation of pomegranate seed oil (Nano-PSO, GranaGard), into newborn asymptomatic TgMHu2ME199K mice modeling for E200K gCJD significantly delayed the advance of clinical disease. In the present study, we tested the individual and combined effects of both treatments in older and sick TgMHu2ME199K mice. We show that while transplantation of NPCs at both initial (140 days) and advance clinical states (230 days) arrested disease progression for about 30 days, after which scores rapidly climbed to those of untreated Tgs, administration of Nano-PSO to transplanted TgMHu2ME199K mice resulted in detention of disease advance for 60-80 days, followed by a slower disease progression thereafter. Pathological examinations demonstrated the combined treatment extended the survival of the transplanted NPCs, and also increased the generation of endogenous stem cells. Our results suggest that administration of Nano-PSO may increase the beneficial effects of NPCs transplantation.

Interventions to reduce the risk of surgically transmitted Creutzfeldt-Jakob disease: a cost-effective modelling review.

BACKGROUND: Creutzfeldt-Jakob disease is a fatal neurological disease caused by abnormal infectious proteins called prions. Prions that are present on surgical instruments cannot be completely deactivated; therefore, patients who are subsequently operated on using these instruments may become infected. This can result in surgically transmitted Creutzfeldt-Jakob disease. OBJECTIVE: To update literature reviews, consultation with experts and economic modelling published in 2006, and to provide the cost-effectiveness of strategies to reduce the risk of surgically transmitted Creutzfeldt-Jakob disease. METHODS: Eight systematic reviews were undertaken for clinical parameters. One review of cost-effectiveness was undertaken. Electronic databases including MEDLINE and EMBASE were searched from 2005 to 2017. Expert elicitation sessions were undertaken. An advisory committee, convened by the National Institute for Health and Care Excellence to produce guidance, provided an additional source of information. A mathematical model was updated focusing on brain and posterior eye surgery and neuroendoscopy. The model simulated both patients and instrument sets. Assuming that there were potentially 15 cases of surgically transmitted Creutzfeldt-Jakob disease between 2005 and 2018, approximate Bayesian computation was used to obtain samples from the posterior distribution of the model parameters to generate results. Heuristics were used to improve computational efficiency. The modelling conformed to the National Institute for Health and Care Excellence reference case. The strategies evaluated included neither keeping instruments moist nor prohibiting set migration; ensuring that instruments were kept moist; prohibiting instrument migration between sets; and employing single-use instruments. Threshold analyses were undertaken to establish prices at which single-use sets or completely effective decontamination solutions would be cost-effective. RESULTS: A total of 169 papers were identified for the clinical review. The evidence from published literature was not deemed sufficiently strong to take precedence over the distributions obtained from expert elicitation. Forty-eight papers were identified in the review of cost-effectiveness. The previous modelling structure was revised to add the possibility of misclassifying surgically transmitted Creutzfeldt-Jakob disease as another neurodegenerative disease, and assuming that all patients were susceptible to infection. Keeping instruments moist was estimated to reduce the risk of surgically transmitted Creutzfeldt-Jakob disease cases and associated costs. Based on probabilistic sensitivity analyses, keeping instruments moist was estimated to on average result in 2.36 (range 0-47) surgically transmitted Creutzfeldt-Jakob disease cases (across England) caused by infection occurring between 2019 and 2023. Prohibiting set migration or employing single-use instruments reduced the estimated risk of surgically transmitted Creutzfeldt-Jakob disease cases further, but at considerable cost. The estimated costs per quality-adjusted life-year gained of these strategies in addition to keeping instruments moist were in excess of £1M. It was estimated that single-use instrument sets (currently £350-500) or completely effective cleaning solutions would need to cost approximately £12 per patient to be cost-effective using a £30,000 per quality-adjusted life-year gained value. LIMITATIONS: As no direct published evidence to implicate surgery as a cause of Creutzfeldt-Jakob disease has been found since 2005, the estimations of potential cases from elicitation are still speculative. A particular source of uncertainty was in the number of potential surgically transmitted Creutzfeldt-Jakob disease cases that may have occurred between 2005 and 2018. CONCLUSIONS: Keeping instruments moist is estimated to reduce the risk of surgically transmitted Creutzfeldt-Jakob disease cases and associated costs. Further surgical management strategies can reduce the risks of surgically transmitted Creutzfeldt-Jakob disease but have considerable associated costs. STUDY REGISTRATION: This study is registered as PROSPERO CRD42017071807. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 11. See the NIHR Journals Library website for further project information.

The aims of this report were to summarise evidence relating to surgically transmitted Creutzfeldt­Jakob disease and to explore the value for money of strategies to reduce the chance of any future surgically transmitted Creutzfeldt­Jakob disease cases. Current recommendations include keeping sets of surgical instruments together for high-risk operations and using separate instruments for people born after 1996. The project involved reviewing published papers, speaking with experts and building a computer model. The literature reviews found that Creutzfeldt­Jakob disease occurs in around 1­2 per million people and that no definite cases of surgically transmitted Creutzfeldt­Jakob disease have been observed since the 1970s. The reviews also looked for information on the possibility of patients being infected with Creutzfeldt­Jakob disease after having surgery on high-risk tissues, such as the brain and the back of the eye. They found that there was a great deal of uncertainty regarding who might have Creutzfeldt­Jakob disease, but not yet have symptoms, as well as the risk of transmission and the ability of strategies to reduce this risk. The computer model aimed to estimate value for money of different strategies to reduce the risks of surgically transmitted Creutzfeldt­Jakob disease. However, the reviews found that some of the numbers needed for the model were not known, so experts were asked to estimate this information instead along with the range of possible values. This information included the effectiveness of different cleaning practices and the chances of infected tissue being transmitted between patients undergoing high-risk surgery. The model found that keeping surgical instruments moist prior to cleaning was likely to save money and reduce the chance of future surgically transmitted Creutzfeldt­Jakob disease cases. However, additional measures, such as using only sets of single-use instruments, ensuring that instruments were kept together in their sets or using separate instruments for those born after 1996, appeared to be poor value for money.

Observance of Sterilization Protocol Guideline Procedures of Critical Instruments for Preventing Iatrogenic Transmission of Creutzfeldt-Jakob Disease in Dental Practice in France, 2017.

Effective sterilization of reusable instruments contaminated by Creutzfeldt⁻Jakob disease in dental care is a crucial issue for public health. The present cross-sectional study investigated how the recommended procedures for sterilization were implemented by French dental practices in real-world settings. A sample of dental practices was selected in the French Rhône-Alpes region. Data were collected by a self-questionnaire in 2016. Sterilization procedures (n = 33) were classified into 4 groups: (1) Pre-sterilization cleaning of reusable instruments; (2) Biological verification of sterilization cycles—Monitoring steam sterilization procedures; (3) Autoclave performance and practitioner knowledge of autoclave use; (4) Monitoring and documentation of sterilization procedures—Tracking and tracing the instrumentation. Answers were provided per procedure, along with the global implementation of procedures within a group (over 80% correctly performed). Then it was verified how adherence to procedure groups varied with the size of the dental practice and the proportion of dental assistants within the team. Among the 179 questionnaires available for the analyses, adherence to the recommended procedures of sterilization noticeably varied between practices, from 20.7% to 82.6%. The median percentages of procedures correctly implemented per practice were 58.1%, 50.9%, 69.2% and 58.2%, in Groups 1, 2, 3 and 4, respectively (corresponding percentages for performing over 80% of the procedures in the group: 23.4%, 6.6%, 46.6% and 38.6%). Dental practices ≥ 3 dental units performed significantly better (>80%) procedures of Groups 2 and 4 (p = 0.01 and p = 0.002, respectively), while no other significant associations emerged. As a rule, practices complied poorly with the recommended procedures, despite partially improved results in bigger practices. Specific training regarding sterilization procedures and a better understanding of the reasons leading to their non-compliance are needed.

Reducing the risk of iatrogenic Creutzfeldt-Jakob disease by improving the cleaning of neurosurgical instruments.

BACKGROUND: In all, there have been 178 variant Creutzfeldt-Jakob disease (vCJD) patients diagnosed in the UK, with an estimated maximum 1:2000 carriage rate based on archived appendix and tonsil tissue, implying that infection may be rare but carriage relatively frequent. Previous workers have identified that maintenance of surgical instruments in a humid atmosphere after use and prior to cleaning assists cleaning efficacy. Recently the Department of Health/Advisory Committee on Dangerous Pathogens UK have recommended a surgical instrument cleanliness threshold post cleaning of <5 µg protein per instrument side. AIM: To quantify cleanliness of neurosurgical instruments and to investigate cost-effective measures for improved cleaning. METHODS: Two instrument protein quantification methods were used: one based on the International Standard (15883 series) using sodium dodecyl sulphate elution and ortho-phthalaldehyde reaction, and a second in-situ protein fluorescence detection system (ProReveal) providing results per instrument side. In-vitro investigation of the efficacy of some commercial and in-house pre-clean wetting agents was undertaken using artificial test soil and stainless steel discs under standard conditions. In-vivo evaluation of best-performing in-vitro agents was undertaken on craniotomy sets. FINDINGS: ProReveal technology demonstrated that 163 out of 187 (87%) neurosurgical instruments had <5 µg residual protein per instrument side. The use of proprietary National Health Service plastic bags and sterile water-soaked wound pads were equivalent in efficacy to commercial pre-cleaning wetting products and significantly less expensive. CONCLUSION: Although we demonstrate low in-situ protein levels on neurosurgical instruments and the beneficial effects of keeping instruments moist, other cleaning critical-control points such as instrument loading patterns should also be monitored.

Detection of Creutzfeldt-Jakob disease prions in skin: implications for healthcare.

Evidence has recently been reported of prion seeding activity in skin tissue from patients with sporadic Creutzfeldt-Jakob disease (sCJD). This is relevant information for infection control measures during surgery. The work uses very sensitive prion assays now available for medical research, and may soon be adapted to related neurodegenerative disorders.

Geographic exposure risk of variant Creutzfeldt-Jakob disease in US blood donors: a risk-ranking model to evaluate alternative donor-deferral policies.

BACKGROUND: Variant Creutzfeldt-Jakob disease (vCJD) has been transmitted by blood transfusion (TTvCJD). The US Food and Drug Administration (FDA) recommends deferring blood donors who resided in or traveled to 30 European countries where they may have been exposed to bovine spongiform encephalopathy (BSE) through beef consumption. Those recommendations warrant re-evaluation, because new cases of BSE and vCJD have markedly abated. STUDY DESIGN AND METHODS: The FDA developed a risk-ranking model to calculate the geographic vCJD risk using country-specific case rates and person-years of exposure of US blood donors. We used the reported country vCJD case rates, when available, or imputed vCJD case rates from reported BSE and UK beef exports during the risk period. We estimated the risk reduction and donor loss should the deferral be restricted to a few high-risk countries. We also estimated additional risk reduction by leukocyte reduction (LR) of red blood cells (RBCs). RESULTS: The United Kingdom, Ireland, and France had the greatest vCJD risk, contributing approximately 95% of the total risk. The model estimated that deferring US donors who spent extended periods of time in these three countries, combined with currently voluntary LR (95% of RBC units), would reduce the vCJD risk by 89.3%, a reduction similar to that achieved under the current policy (89.8%). Limiting deferrals to exposure in these three countries would potentially allow donations from an additional 100,000 donors who are currently deferred. CONCLUSION: Our analysis suggests that a deferral option focusing on the three highest risk countries would achieve a level of blood safety similar to that achieved by the current policy.

Meeting Report: 2015 PDA Virus & TSE Safety Forum.

The report provides a summary of the presentations at the Virus & TSE Safety Forum 2015 organized by the Parenteral Drug Association (PDA) and held in Cascais, Portugal, from 9 to 11 June, 2015. As with previous conferences of this series, the PDA Virus & TSE Safety Forum 2015 provided an excellent forum for the exchange of information and opinions between the industry, research organizations, and regulatory bodies. Regulatory updates on virus and TSE safety aspects illustrating current topics of discussion at regulatory agencies in Europe and the United States were provided; the conference covered emerging viruses and new virus detection systems that may be used for the investigation of human pathogenic viruses as well as the virus safety of cell substrates and of raw material of ovine/caprine or human origin. Progress of development and use of next-generation sequencing methods was shown by several examples. Virus clearance data illustrating the effectiveness of inactivation or removal methods were presented and data provided giving insight into the mechanism of action of these technologies. In the transmissible spongiform encephalopathy (TSE) part of the conference, the epidemiology of variant Creutzfeldt-Jakob disease was reviewed and an overview about diagnostic tests provided; current thinking about the spread and propagation of prions was presented and the inactivation of prions by disinfection (equipment) and in production of bovine-derived reagents (heparin) shown. The current report provides an overview about the outcomes of the 2015 PDA Virus & TSE Safety Forum, a unique event in this field.

Rapid and Highly Sensitive Detection of Variant Creutzfeldt-Jakob Disease Abnormal Prion Protein on Steel Surfaces by Protein Misfolding Cyclic Amplification: Application to Prion Decontamination Studies.

The prevalence of variant Creutzfeldt-Jakob disease (vCJD) in the population remains uncertain, although it has been estimated that 1 in 2000 people in the United Kingdom are positive for abnormal prion protein (PrPTSE) by a recent survey of archived appendix tissues. The prominent lymphotropism of vCJD prions raises the possibility that some surgical procedures may be at risk of iatrogenic vCJD transmission in healthcare facilities. It is therefore vital that decontamination procedures applied to medical devices before their reprocessing are thoroughly validated. A current limitation is the lack of a rapid model permissive to human prions. Here, we developed a prion detection assay based on protein misfolding cyclic amplification (PMCA) technology combined with stainless-steel wire surfaces as carriers of prions (Surf-PMCA). This assay allowed the specific detection of minute quantities (10-8 brain dilution) of either human vCJD or ovine scrapie PrPTSE adsorbed onto a single steel wire, within a two week timeframe. Using Surf-PMCA we evaluated the performance of several reference and commercially available prion-specific decontamination procedures. Surprisingly, we found the efficiency of several marketed reagents to remove human vCJD PrPTSE was lower than expected. Overall, our results demonstrate that Surf-PMCA can be used as a rapid and ultrasensitive assay for the detection of human vCJD PrPTSE adsorbed onto a metallic surface, therefore facilitating the development and validation of decontamination procedures against human prions.

Rapid chemical decontamination of infectious CJD and scrapie particles parallels treatments known to disrupt microbes and biofilms.

Neurodegenerative human CJD and sheep scrapie are diseases caused by several different transmissible encephalopathy (TSE) agents. These infectious agents provoke innate immune responses in the brain, including late-onset abnormal prion protein (PrP-res) amyloid. Agent particles that lack detectable PrP sequences by deep proteomic analysis are highly infectious. Yet these agents, and their unusual resistance to denaturation, are often evaluated by PrP amyloid disruption. To reexamine the intrinsic resistance of TSE agents to denaturation, a paradigm for less resistant viruses and microbes, we developed a rapid and reproducible high yield agent isolation procedure from cultured cells that minimized PrP amyloid and other cellular proteins. Monotypic neuronal GT1 cells infected with the FU-CJD or 22L scrapie agents do not have complex brain changes that can camouflage infectious particles and prevent their disruption, and there are only 2 reports on infectious titers of any human CJD strain treated with chemical denaturants. Infectious titers of both CJD and scrapie were reduced by >4 logs with Thiourea-urea, a treatment not previously tested. A mere 5 min exposure to 4M GdnHCl at 22°C reduced infectivity by >5 logs. Infectious 22L particles were significantly more sensitive to denaturation than FU-CJD particles. A protocol using sonication with these chemical treatments may effectively decontaminate complicated instruments, such as duodenoscopes that harbor additional virulent microbes and biofilms associated with recent iatrogenic infections.