Updated global epidemiology atlas of human prion diseases.

Introduction: Human prion disease (PrD), a group of fatal and transmissible neurodegenerative diseases, consists of Creutzfeldt-Jakob disease (CJD), kuru, fatal familial insomnia (FFI), Gerstmann-Sträussler-Scheinker disease (GSS), and variably protease-sensitive prionopathy (VPSPr). The emergence of bovine spongiform encephalopathy (BSE) in cattle and variant CJD (vCJD) has greatly threatened public health, both in humans and animals. Since the 1990's, dozens of countries and territories have conducted PrD surveillance programs. Methods: In this study, the case numbers and alternative trends of different types of PrD globally and in various countries or territories from 1993 to 2020 were collected and analyzed based on the data from the websites of the international and national PrD surveillance programs, as well as from relevant publications. Results: The total numbers of the reported PrD and sporadic CJD (sCJD) cases in 34 countries with accessible annual case numbers were 27,872 and 24,623, respectively. The top seven countries in PrD cases were the USA (n = 5,156), France (n = 3,276), Germany (n = 3,212), Italy (n = 2,995), China (n = 2,662), the UK (n = 2,521), Spain (n = 1,657), and Canada (n = 1,311). The annual PrD case numbers and mortalities, either globally or in the countries, showed an increased trend in the past 27 years. Genetic PrD cases accounted for 10.83% of all reported PrD cases; however, the trend varied largely among the different countries and territories. There have been 485 iatrogenic CJD (iCJD) cases and 232 vCJD cases reported worldwide. Discussion: The majority of the countries with PrD surveillance programs were high- and upper-middle-income countries. However, most low- and lower-middle-income countries in the world did not conduct PrD surveillance or even report PrD cases, indicating that the number of human PrD cases worldwide is markedly undervalued. Active international PrD surveillance for both humans and animals is still vital to eliminate the threat of prion disease from a public health perspective.

Prospective 25-year surveillance of prion diseases in France, 1992 to 2016: a slow waning of epidemics and an increase in observed sporadic forms.

BackgroundPrion diseases are rare, fatal disorders that have repeatedly raised public health concerns since the early 1990s. An active prion disease surveillance network providing national level data was implemented in France in 1992.AimWe aimed to describe the epidemiology of sporadic, genetic and infectious forms of prion diseases in France since surveillance implementation.MethodsWe included all suspected cases notified from January 1992 to December 2016, and cases who died during the period with a definite or probable prion disease diagnosis according to EuroCJD criteria. Demographic, clinical, genetic, neuropathological and biochemical data were collected.ResultsIn total, 25,676 suspected cases were notified and 2,907 were diagnosed as prion diseases, including 2,510 (86%) with sporadic Creutzfeldt-Jakob disease (sCJD), 240 (8%) genetic and 157 (6%) with infectious prion disease. Suspected cases and sCJD cases increased over time. Younger sCJD patients (≤ 50 years) showed phenotypes related to a distinct molecular subtype distribution vs those above 50 years. Compared to other European countries, France has had a higher number of cases with iatrogenic CJD after growth hormone treatment and variant CJD (vCJD) linked to bovine spongiform encephalopathy (second after the United Kingdom), but numbers slowly decreased over time.ConclusionWe observed a decrease of CJD infectious forms, demonstrating the effectiveness of measures to limit human exposure to exogenous prions. However, active surveillance is needed regarding uncertainties about future occurrences of vCJD, possible zoonotic potential of chronic wasting diseases in cervids and increasing trends of sCJD observed in France and other countries.

Creutzfeldt-Jakob disease surveillance in Australia: update to 31 December 2022.

Creutzfeldt-Jakob disease surveillance in Australia: update to 31 December 2022: Nationwide surveillance of Creutzfeldt-Jakob disease (CJD) and other human prion diseases is performed by the Australian National Creutzfeldt-Jakob Disease Registry (ANCJDR). National surveillance encompasses the period since 1 January 1970, with prospective surveillance occurring from 1 October 1993. Over this prospective surveillance period, considerable developments have occurred in pre-mortem diagnostics; in the delineation of new disease subtypes; and in a heightened awareness of prion diseases in healthcare settings. Surveillance practices of the ANCJDR have evolved and adapted accordingly. This report summarises the activities of the ANCJDR during 2022. Since the ANCJDR began offering diagnostic cerebrospinal fluid (CSF) 14-3-3 protein testing in Australia in September 1997, the annual number of referrals has steadily increased. In 2022, a total of 599 domestic CSF specimens were referred for diagnostic testing and 79 persons with suspected human prion disease were formally added to the national register. As of 31 December 2022, just under half of the 79 suspect case notifications (36/79) remain classified as 'incomplete'; 15 cases were classified as 'definite' and 23 as 'probable' prion disease; five cases were excluded through neuropathological examination. For 2022, fifty-five percent of all suspected human-prion-disease-related deaths in Australia underwent neuropathological examination. No cases of variant or iatrogenic CJD were identified. The SARS-CoV-2 pandemic did not affect prion disease surveillance outcomes in Australia during 2022.

[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.

Creutzfeldt-Jakob disease surveillance in Australia: update to 31 December 2021.

Nationwide surveillance of Creutzfeldt-Jakob disease (CJD) and other human prion diseases is performed by the Australian National Creutzfeldt-Jakob Disease Registry (ANCJDR). National surveillance encompasses the period since 1 January 1970, with prospective surveillance occurring from 1 October 1993. Over this prospective surveillance period, considerable developments have occurred in pre-mortem diagnostics; in the delineation of new disease subtypes; and in a heightened awareness of prion diseases in healthcare settings. Surveillance practices of the ANCJDR have evolved and adapted accordingly. This report summarises the activities of the ANCJDR during 2021. Since the ANCJDR began offering diagnostic cerebrospinal fluid (CSF) 14-3-3 protein testing in Australia in September 1997, the annual number of referrals has steadily increased. In 2021, a total of 548 domestic CSF specimens were referred for 14-3-3 protein testing; 73 persons with suspected human prion disease were formally added to the national register. As of 31 December 2021, just over half of the 73 suspect case notifications (37/73) remain classified as 'incomplete'; 17 cases were classified as 'definite' and 13 as 'probable' prion disease; six cases were excluded through either detailed clinical follow-up (two cases) or neuropathological examination (four cases). For 2021, sixty-four percent of all suspected human-prion-disease-related deaths in Australia underwent neuropathological examination. No cases of variant or iatrogenic CJD were identified. The SARS-CoV-2 pandemic did not affect prion disease surveillance outcomes in Australia.

Prevalence and Treatments of Movement Disorders in Prion Diseases: A Longitudinal Cohort Study.

BACKGROUND: Prion diseases cause a range of movement disorders involving the cortical, extrapyramidal, and cerebellar systems, and yet there are no large systematic studies of their prevalence, features, associations, and responses to commonly used treatments. OBJECTIVES: We sought to describe the natural history and pharmacological management of movement disorders in prion diseases. METHODS: We studied the serial examination findings, investigation results, and symptomatic treatment recorded for 700 patients with prion diseases and 51 mimics who had been enrolled onto the prospective longitudinal National Prion Monitoring Cohort study between 2008 and 2020. We performed an analysis to identify whether there were patterns of movement disorders associated with disease aetiology, PRNP codon 129 polymorphism, disease severity rating scales, magnetic resonance imaging (MRI) and cerebrospinal fluid (CSF) findings. RESULTS: Gait disturbances, myoclonus, and increased tone are the most frequently observed movement disorders in patients with prion diseases. The typical pattern of early motor dysfunction involves gait disturbance, limb ataxia, impaired smooth pursuit, myoclonus, tremor, and increased limb tone. Disturbances of gait, increased tone, and myoclonus become more prevalent and severe as the disease progresses. Chorea, alien limb phenomenon, and nystagmus were the least frequently observed movement disorders, with these symptoms showing spontaneous resolution in approximately half of symptomatic patients. Disease severity and PRNP codon 129 polymorphism were associated with different movement disorder phenotypes. Antiepileptics and benzodiazepines were found to be effective in treating myoclonus. CONCLUSIONS: We describe the prevalence, severity, evolution, treatment, and associated features of movement disorders in prion diseases based on a prospective cohort study. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Transmission, Strain Diversity, and Zoonotic Potential of Chronic Wasting Disease.

Chronic wasting disease (CWD) is a prion disease affecting several species of captive and free-ranging cervids. In the past few decades, CWD has been spreading uncontrollably, mostly in North America, resulting in a high increase of CWD incidence but also a substantially higher number of geographical regions affected. The massive increase in CWD poses risks at several levels, including contamination of the environment, transmission to animals cohabiting with cervids, and more importantly, a putative transmission to humans. In this review, I will describe the mechanisms and routes responsible for the efficient transmission of CWD, the strain diversity of natural CWD, its spillover and zoonotic potential and strategies to minimize the CWD threat.

Estimation of the number of inherited prion disease mutation carriers in the UK.

Inherited prion diseases (IPD) are a set of rare neurodegenerative diseases that are always caused by mutation of the prion protein gene (PRNP). These are highly heterogeneous in clinical presentation and best described by the specific gene mutation, but traditionally include the canonical syndromes familial Creutzfeldt-Jakob disease, Gerstamann-Straussler-Scheinker syndrome, and fatal familial insomnia. In the UK, care of IPD patients and clinical PRNP sequencing have been carried out almost exclusively by the National Prion Clinic and affiliated laboratories since the disease gene was discovered in 1989. Using data obtained over 30 years (1990-2019), this study aimed to provide a greater understanding of the genetic prevalence of IPD using multiple complementary methods. A key source of bias in rare disorders is ascertainment, so we included an analysis based on capture-recapture techniques that may help to minimise ascertainment bias. 225 patients, with 21 different IPD mutations were identified, varying in frequency (with 8/21 mutations comprising over 90% observed cases), derived from 116 kindreds and 151 3-generation families. We estimated a total of 303 UK families (95% CI = 222, 384) segregate IPD mutations, 1091 (95% CI = 720, 1461) UK mutation carriers and a lifetime risk of approximately 1 in 60,000. Simpler methods of measuring prevalence based on extrapolation from the annual incidence of disease, and large scale genomic studies, result in similar estimates of prevalence. These estimates may be of value for planning preventive trials of therapeutics in IPD mutation carriers, prevention of prion disease transmission and provision of specialist services.

Difference of geographic distributions of the Chinese patients with prion diseases in the permanent resident places and referring places.

Human prion diseases (PrDs) are a group of transmissible neurodegenerative diseases that can be clarified as sporadic, genetic and iatrogenic forms. In this study, we have analysed the time and geographic distributions of 2011 PrD cases diagnosed by China National Surveillance for Creutzfeldt-Jakob disease (CNS-CJD) since 2006, including 1792 sporadic CJD (sCJD) cases and 219 gPrD cases. Apparently, the cases numbers of both sCJD and gPrD increased along with the surveillance years, showing a stepping up every five years. The geographic distributions of the PrDs cases based on the permanent residences were wide, distributing in 30 out of 31 provincial-level administrative divisions in Chinese mainland. However, the case numbers in the provincial level varied largely. The provinces in the eastern part of China had much more cases than those in the western part. Normalized the case numbers with the total population each province revealed higher incidences in six provinces. Further, the resident and referring places of all PrD cases were analysed, illustrating a clear concentrating pattern of referring in the large metropolises. Five provincial-level administrative divisions reported more PrD cases from other provinces than the local ones. Particularly, BJ reported not only more than one-fourth of all PrDs cases in Chinese mainland but also 3.64-fold more PrDs cases from other provinces than its local ones. We believed that good medical resources, well-trained programmes and knowledge of PrDs in the clinicians and the CDC staffs contributed to well-referring PrD cases in those large cities.

Genetic Prion Disease: Insight from the Features and Experience of China National Surveillance for Creutzfeldt-Jakob Disease.

Human genetic prion diseases (gPrDs) are directly associated with mutations and insertions in the PRNP (Prion Protein) gene. We collected and analyzed the data of 218 Chinese gPrD patients identified between Jan 2006 and June 2020. Nineteen different subtypes were identified and gPrDs accounted for 10.9% of all diagnosed PrDs within the same period. Some subtypes of gPrDs showed a degree of geographic association. The age at onset of Chinese gPrDs peaked in the 50-59 year group. Gerstmann-Sträussler-Scheinker syndrome (GSS) and fatal familial insomnia (FFI) cases usually displayed clinical symptoms earlier than genetic Creutzfeldt-Jakob disease (gCJD) patients with point mutations. A family history was more frequently recalled in P105L GSS and D178N FFI patients than T188K and E200K patients. None of the E196A gCJD patients reported a family history. The gCJD cases with point mutations always developed clinical manifestations typical of sporadic CJD (sCJD). EEG examination was not sensitive for gPrDs. sCJD-associated abnormalities on MRI were found in high proportions of GSS and gCJD patients. CSF 14-3-3 positivity was frequently detected in gCJD patients. Increased CSF tau was found in more than half of FFI and T188K gCJD cases, and an even higher proportion of E196A and E200K gCJD patients. 63.6% of P105L GSS cases showed a positive reaction in cerebrospinal fluid RT-QuIC. GSS and FFI cases had longer durations than most subtypes of gCJD. This is one of the largest studies of gPrDs in East Asians, and the illness profile of Chinese gPrDs is clearly distinct. Extremely high proportions of T188K and E196A occur among Chinese gPrDs; these mutations are rarely reported in Caucasians and Japanese.

Viral and Prion Infections Associated with Central Nervous System Syndromes in Brazil.

Virus-induced infections of the central nervous system (CNS) are among the most serious problems in public health and can be associated with high rates of morbidity and mortality, mainly in low- and middle-income countries, where these manifestations have been neglected. Typically, herpes simplex virus 1 and 2, varicella-zoster, and enterovirus are responsible for a high number of cases in immunocompetent hosts, whereas other herpesviruses (for example, cytomegalovirus) are the most common in immunocompromised individuals. Arboviruses have also been associated with outbreaks with a high burden of neurological disorders, such as the Zika virus epidemic in Brazil. There is a current lack of understanding in Brazil about the most common viruses involved in CNS infections. In this review, we briefly summarize the most recent studies and findings associated with the CNS, in addition to epidemiological data that provide extensive information on the circulation and diversity of the most common neuro-invasive viruses in Brazil. We also highlight important aspects of the prion-associated diseases. This review provides readers with better knowledge of virus-associated CNS infections. A deeper understanding of these infections will support the improvement of the current surveillance strategies to allow the timely monitoring of the emergence/re-emergence of neurotropic viruses.

Prion Dissemination through the Environment and Medical Practices: Facts and Risks for Human Health.

Prion diseases are a group of fatal, infectious neurodegenerative disorders affecting various species of mammals, including humans. The infectious agent in these diseases, termed prion, is composed exclusively of a misfolded protein that can spread and multiply in the absence of genetic materials. In this article, we provide an overview of the mechanisms of prion replication, interindividual transmission, and dissemination in communities. In particular, we review the potential role of the natural environment in prion transmission, including the mechanisms and pathways for prion entry and accumulation in the environment as well as its roles in prion mutation, adaptation, evolution, and transmission. We also discuss the transmission of prion diseases through medical practices, scientific research, and use of biological products. Detailed knowledge of these aspects is crucial to limit the spreading of existing prion diseases as well as to prevent the emergence of new diseases with possible catastrophic consequences for public health.

Creutzfeldt-Jakob disease surveillance in Australia: update to 31 December 2020.

ABSTRACT: Nationwide surveillance of Creutzfeldt-Jakob disease and other human prion diseases is performed by the Australian National Creutzfeldt-Jakob Disease Registry (ANCJDR). National surveillance encompasses the period since 1 January 1970, with prospective surveillance occurring from 1 October 1993. Over this prospective surveillance period, considerable developments have occurred in pre-mortem diagnostics; in the delineation of new disease subtypes; and in a heightened awareness of prion diseases in healthcare settings. Surveillance practices of the ANCJDR have evolved and adapted accordingly. This report summarises the activities of the ANCJDR during 2020. Since the ANCJDR began offering diagnostic cerebrospinal fluid (CSF) 14-3-3 protein testing in Australia in September 1997, the annual number of referrals has steadily increased. In 2020, 510 domestic CSF specimens were referred for 14-3-3 protein testing and 85 persons with suspected human prion disease were formally added to the national register. As of 31 December 2020, just over half (44 cases) of the 85 suspect case notifications remain classified as 'incomplete'; 27 cases were excluded through either detailed clinical follow-up (9 cases) or neuropathological examination (18 cases); 18 cases were classified as 'definite' and eleven as 'probable' prion disease. For 2020, sixty percent of all suspected human-prion-disease-related deaths in Australia underwent neuropathological examination. No cases of variant or iatrogenic CJD were identified. The SARS-CoV-2 pandemic did not affect prion disease surveillance outcomes in Australia.

Human prion disease surveillance in Spain, 1993-2018: an overview.

In Spain, human transmissible spongiform encephalopathies (TSEs) have been undergoing continuous surveillance for over 25 years. In 1995, the system was launched as an EU Concerted Action, with EU surveillance network procedures being incorporated from 2002 onwards. The aim of this report was to describe performance and outcomes of this surveillance system across the period 1993-2018. Neurology and public health specialists from every region reported cases to a central hub at the Carlos III Health Institute, Madrid. In all, eight accidentally transmitted cases and five definite variant Creutzfeldt-Jakob disease (vCJD) patients were reported. All vCJD cases were diagnosed between 2005 and 2008. Two of these were family/dietary-related and spatially linked to a third. Yearly incidence of sporadic CJD per million was 1.25 across the period 1998-2018, and displayed a north-south gradient with the highest incidence in La Rioja, Navarre and the Basque Country. Genetic TSEs were observed to be clustered in the Basque Country, with a 4-fold incidence over the national rate. A total of 120 (5.6%) non-TSE sporadic, conformational, rapidly progressing neurodegenerative and vascular brain disorders were reported as suspect CJD. We conclude that TSEs in Spain displayed geographically uneven, stable medium incidences for the sporadic and genetic forms, a temporal and spatial family cluster for vCJD, and decreasing numbers for dura-mater-associated forms. The vCJD surveillance, framed within the EU network, might require continuing to cover all prion disorders. There is need for further strategic surveillance research focusing on case definition of rapid-course, conformational encephalopathies and surgical risk.

The importance of ongoing international surveillance for Creutzfeldt-Jakob disease.

Creutzfeldt-Jakob disease (CJD) is a rapidly progressive, fatal and transmissible neurodegenerative disease associated with the accumulation of misfolded prion protein in the CNS. International CJD surveillance programmes have been active since the emergence, in the mid-1990s, of variant CJD (vCJD), a disease linked to bovine spongiform encephalopathy. Control measures have now successfully contained bovine spongiform encephalopathy and the incidence of vCJD has declined, leading to questions about the requirement for ongoing surveillance. However, several lines of evidence have raised concerns that further cases of vCJD could emerge as a result of prolonged incubation and/or secondary transmission. Emerging evidence from peripheral tissue distribution studies employing high-sensitivity assays suggests that all forms of human prion disease carry a theoretical risk of iatrogenic transmission. Finally, emerging diseases, such as chronic wasting disease and camel prion disease, pose further risks to public health. In this Review, we provide an up-to-date overview of the transmission of prion diseases in human populations and argue that CJD surveillance remains vital both from a public health perspective and to support essential research into disease pathophysiology, enhanced diagnostic tests and much-needed treatments.

OPPORTUNISTIC SURVEILLANCE OF CAPTIVE AND FREE-RANGING BIGHORN SHEEP (OVIS CANADENSIS) IN COLORADO, USA, FOR TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHIES.

Bighorn sheep (Ovis canadensis) are predicted to have a degree of susceptibility to the transmissible spongiform encephalopathies (TSE) chronic wasting disease and scrapie. We opportunistically screened 127 captive bighorn sheep and 152 free-ranging bighorn sheep in Colorado, US for the presence of TSE over a period of 35 yr. None of the animals demonstrated clinical signs, gross pathology, histopathology, or immunohistochemical staining patterns suggestive of TSE.

Prion diseases reported in the "Annual of the Pathological Autopsy Cases in Japan".

BACKGROUND: For surveillance projects to be successful, it is important to accurately diagnose all patients, without overlooking any cases. Here, we investigated the present clinical diagnostic accuracy for prion diseases in Japan. METHODS: We analyzed volumes of the "Annual of the Pathological Autopsy Cases in Japan", which reported details on 130,105 autopsies conducted from 2007 to 2016 throughout Japan. RESULTS: The clinical diagnosis of patients with prion disease had a specificity of 91.3% and a sensitivity of 96.3%. The autopsy rates were estimated as 17.8% for patients with clinically suspected prion disease and as 1.8% for the entire population. CONCLUSIONS: Despite the good accuracy of clinical diagnoses of prion diseases, a calculated 78.4 patients with prion disease were expected to have gone undiagnosed during the 10-year study period. However, autopsy is estimated to reveal a maximum of only 13.8 of these clinically undiagnosed patients because of the low autopsy rate. The overall autopsy rate, irrespective of any specific disorder, must increase for effective surveillance projects of disease incidence to be conducted.

[Prion diseases and the biosecurity problems.]

The review presents the current state of the problem of prions and prion diseases with an emphasis on theepidemiological and epizootological risks of pathogens that cause fatal neurodegenerative diseases in humans and animals. The results of molecular genetic studies of the conversion of normal PrPc prion protein molecules to infectious forms of PrPd, resistance to physical disinfection methods, in particular exceptional thermal stability, and their ability to overcome interspecific barriers, while increasing virulence, are described. The possibility of infection not only by nutrition, when eating even heat-treated meat of sick animals, but also due to surgical interventions, especially neurosurgical and ophthalmic, as well as the use of immunobiological preparations, are emphasized. Since there are currently no means for the effective treatment of prion diseases in the world, attention is drawn to the high degree of relevance for the biosafety of the country to develop domestic highly sensitive test systems that can effectively detect prion infectious protein in vivo at the preclinical stage of the disease. The latest methods of automatic protein amplification and identification of prion proteins are briefly described as the most promising areas of research in the field of diagnosis of prion diseases.

Prion disease and recommended procedures for flexible endoscope reprocessing - a review of policies worldwide and proposal for a simplified approach.

Several guidelines recommend specific treatments for endoscopes, procedures of quarantine for endoscopes, or additional treatments for the endoscope washer disinfector (EWD) in suspected or confirmed cases of Creutzfeldt-Jakob disease (CJD) or variant CJD (vCJD) but vary in many details. This study therefore reviewed guidelines on reprocessing flexible endoscopes after use in patients with suspected or confirmed prion disease. In addition, a literature search was performed in Medline on prion, CJD, vCJD, chemical inactivation, transmission healthcare, epidemiology healthcare, concentration tissue human and endoscope. Thus far, no case of CJD or vCJD transmitted by flexible endoscope has been reported. In animals it has been shown that oral uptake of 0.1-5 g of bovine spongiform encephalopathy (BSE)-infected brain homogenate is necessary for transmission. The maximum prion concentration in other tissues (e.g., terminal ileum) is at least 100-fold lower. Automated cleaning of endoscopes alone results in very low total residual protein ≤5.6 mg per duodenoscopes. Recommendations vary between countries, sometimes with additional cleaning, use of alkaline cleaners, no use of cleaners with fixative properties, use of disinfectants without fixative properties or single-use disinfectants. Sodium hydroxide (1 M) and sodium hypochlorite (10,000 and 25,000 mg/L) are very effective in preventing transmission via contaminated wires implanted into animal brains, but their relevance for endoscopes is questionable. Based on circumstantial evidence, it is proposed to consider validated reprocessing as appropriate in the case of delayed suspected prion disease when immediate bedside cleaning, routine use of alkaline cleaners, no fixative agents anywhere prior to disinfection and single use brushes and cleaning solutions can be assured.