Monday, October 19, 2009

Atypical BSE, BSE, and other human and animal TSE in North America Update October 19, 2009

October 19, 2009


An update of sorts on atypical BSE and other TSE in North America, reported, and or, not reported. Please remember, the _typical_ U.K. c-BSE, the l-BSE (BASE), and the h-BSE have all been documented in North America, along with the typical scrapie's, and atypical Nor-98 Scrapie, and to date, 2 different strains of CWD, and also TME. please remember, all these TSE in different species have been rendered and feed to food producing animals for humans and animals in North America (absolutely no idea of TSE in cats and dogs see reference on that), and that the trading of these TSEs via animals and products via the USA and Canada has been so immense over the years, decades, that it was like swapping spit between two lovers. also, please remember, in my opinion (I will show the facts to prove this), Canada is Looking to find TSE in cattle, and the USA has done just the opposite, the look NOT to find and report. The SSS policy has been in full force in the USA for some time. also, there will be some additional information on Transmission studies. Also, what about any human TSE there from, and the surveillance there of ???

With that said, I present you with these facts as follows. There is new data mixed up with old data, so don't miss any of it. ...kind regards, terry

Wednesday, February 11, 2009

Atypical BSE North America Update February 2009 Both of the BSE cases ascertained in the US native-born cattle were atypical cases (H-type), which contributed to the initial ambiguity of the diagnosis. 174, 185 In Canada, there have been 2 atypical BSE cases in addition to the 14 cases of the classic UK strain of BSE2: one was the H-type, and the other was of the L-type.198


source : Enhanced Abstract Journal of the American Veterinary Medical Association January 1, 2009, Vol. 234, No. 1, Pages 59-72 Bovine spongiform encephalopathy Jane L. Harman, DVM, PhD; Christopher J. Silva, PhD

October 2009


Infectivity in skeletal muscle of BASE-infected cattle

Silvia Suardi1, Chiara Vimercati1, Fabio Moda1, Ruggerone Margherita1, Ilaria Campagnani1, Guerino Lombardi2, Daniela Gelmetti2, Martin H. Groschup3, Anne Buschmann3, Cristina Casalone4, Maria Caramelli4, Salvatore Monaco5, Gianluigi Zanusso5, Fabrizio Tagliavini1 1Carlo Besta” Neurological Institute,Italy; 2IZS Brescia, Italy; 33FLI Insel Riems, D, Germany; 4CEA-IZS Torino, Italy; 5University of Verona, Italy

Background: BASE is an atypical form of bovine spongiform encephalopathy caused by a prion strain distinct from that of BSE. Upon experimental transmission to cattle, BASE induces a previously unrecognized disease phenotype marked by mental dullness and progressive atrophy of hind limb musculature. Whether affected muscles contain infectivity is unknown. This is a critical issue since the BASE strain is readily transmissible to a variety of hosts including primates, suggesting that humans may be susceptible.

Objectives: To investigate the distribution of infectivity in peripheral tissues of cattle experimentally infected with BASE. Methods: Groups of Tg mice expressing bovine PrP (Tgbov XV, n= 7-15/group) were inoculated both i.c. and i.p. with 10% homogenates of a variety of tissues including brain, spleen, cervical lymph node, kidney and skeletal muscle (m. longissimus dorsi) from cattle intracerebrally infected with BASE. No PrPres was detectable in the peripheral tissues used for inoculation either by immunohistochemistry or Western blot.

Results: Mice inoculated with BASE-brain homogenates showed clinical signs of disease with incubation and survival times of 175±15 and 207±12 days. Five out of seven mice challenged with skeletal muscle developed a similar neurological disorder, with incubation and survival times of 380±11 and 410±12 days. At present (700 days after inoculation) mice challenged with the other peripheral tissues are still healthy. The neuropathological phenotype and PrPres type of the affected mice inoculated either with brain or muscle were indistinguishable and matched those of Tgbov XV mice infected with natural BASE.

Discussion: Our data indicate that the skeletal muscle of cattle experimentally infected with BASE contains significant amount of infectivity, at variance with BSE-affected cattle, raising the issue of intraspecies transmission and the potential risk for humans. Experiments are in progress to assess the presence of infectivity in skeletal muscles of natural BASE.


Transmission of atypical BSE in humanized mouse models

Liuting Qing1, Wenquan Zou1, Cristina Casalone2, Martin Groschup3, Miroslaw Polak4, Maria Caramelli2, Pierluigi Gambetti1, Juergen Richt5, Qingzhong Kong1 1Case Western Reserve University, USA; 2Instituto Zooprofilattico Sperimentale, Italy; 3Friedrich-Loeffler-Institut, Germany; 4National Veterinary Research Institute, Poland; 5Kansas State University (Previously at USDA National Animal Disease Center), USA

Background: Classical BSE is a world-wide prion disease in cattle, and the classical BSE strain (BSE-C) has led to over 200 cases of clinical human infection (variant CJD). Atypical BSE cases have been discovered in three continents since 2004; they include the L-type (also named BASE), the H-type, and the first reported case of naturally occurring BSE with mutated bovine PRNP (termed BSE-M). The public health risks posed by atypical BSE were largely undefined.

Objectives: To investigate these atypical BSE types in terms of their transmissibility and phenotypes in humanized mice.

Methods: Transgenic mice expressing human PrP were inoculated with several classical (C-type) and atypical (L-, H-, or Mtype) BSE isolates, and the transmission rate, incubation time, characteristics and distribution of PrPSc, symptoms, and histopathology were or will be examined and compared.

Results: Sixty percent of BASE-inoculated humanized mice became infected with minimal spongiosis and an average incubation time of 20-22 months, whereas only one of the C-type BSE-inoculated mice developed prion disease after more than 2 years. Protease-resistant PrPSc in BASE-infected humanized Tg mouse brains was biochemically different from bovine BASE or sCJD. PrPSc was also detected in the spleen of 22% of BASE-infected humanized mice, but not in those infected with sCJD. Secondary transmission of BASE in the humanized mice led to a small reduction in incubation time. The atypical BSE-H strain is also transmissible with distinct phenotypes in the humanized mice, but no BSE-M transmission has been observed so far.

Discussion: Our results demonstrate that BASE is more virulent than classical BSE, has a lymphotropic phenotype, and displays a modest transmission barrier in our humanized mice. BSE-H is also transmissible in our humanized Tg mice. The possibility of more than two atypical BSE strains will be discussed. Supported by NINDS NS052319, NIA AG14359, and NIH AI 77774.


Differences in the expression levels of selected genes in the brain tissue of cattle naturally infected with classical and atypical BSE.

Magdalena Larska1, Miroslaw P. Polak1, Jan F. Zmudzinski1, Juan M. Torres2 1National Veterinary Institute, Poland; 2CISA/INIA

Background: Recently cases of BSE in older cattle named BSE type L and type H were distinguished on the basis of atypical glycoprofiles of PrPres. The nature of those strains is still not fully understood but it is suspected that the atypical BSE cases are sporadic. Hitherto most BSE cases were studied in respect to the features of PrPSc. Here we propose gene expression profiling as a method to characterize and distinguish BSE strains.

Objectives: The aim of the study was to compare the activities of some factors which are known to play a role in TSE’s pathogenesis in order to distinguish the differences/similarities between all BSE types. Methods: 10 % homogenate of brain stem tissue collected from obex region of medulla oblongata from 20 naturally infected BSE cows (8 assigned as classical BSE, other 8 and 4 infected with atypical BSE L type and H type respectively) was used in the study. As negative control animals we’ve used 8 animals in the age between 2.5 and 13 years. The genes were relatively quantified using SYBR Green real time RT-PCR. Raw data of Ct values was transformed into normalized relative quantities using Qbase Plus®.

Results and Discussion: In most of the tested genes significant differences in the expression levels between the brain stem of healthy cattle and animals infected with different BSE types were observed. In c-type BSE in comparison to healthy and atypical BSE the overexpression of the gene of bcl-2, caspase 3, 14-3-3 and tylosine kinase Fyn was significant. Simultaneously in atypical BSEs type-L and type-H the levels of prion protein, Bax and LPR gene was elevated in comparison to c-BSE. Additionally L-BSE was characterized by the overexpression of STI1 and SOD genes compared to the other of BSE types. The downregulation of the gene encoding NCAM1 was observed in all BSE types in comparison to healthy cows. Different gene expression profiles of bovine brains infected with classical and atypical BSE indicates possible different pathogenesis or source of the disease.


Transmission of uncommon forms of bovine prions to transgenic mice expressing human PrP: questions and progress

Vincent Béringue, Hubert Laude INRA, UR 892, Virologie Immunologie Moléculaires, France

The active, large-scale testing of livestock nervous tissues for the presence of protease-resistant prion protein (PrPres) has led to the recognition of 2 uncommon PrPres molecular signatures, termed H-type and L-type BSE. Their experimental transmission to various transgenic and inbred mouse lines unambiguously demonstrated the infectious nature of such cases and the existence of distinct prion strains in cattle. Like the classical BSE agent, H- and L-type (or BASE) prions can propagate in heterologous species. In addition L-type prions acquire molecular and neuropathologic phenotypic traits undistinguishable from BSE or BSE-related agents upon transmission to transgenic mice expressing ovine PrP (VRQ allele) or wild-type mice. An understanding of the transmission properties of these newly recognized prions when confronted with human PrP sequence was therefore needed. Toward this end, we inoculated mice expressing human PrP Met129 with several field isolates. Unlike classical BSE agent, L-type prions appeared to propagate in these mice with no obvious transmission barrier. In contrast, we repeatedly failed to infect them with Htype prions. Ongoing investigations aim to extend the knowledge on these uncommon strains: are these agents able to colonize lymphoid tissue, a potential key factor for successful transmission by peripheral route; is there any relationship between these assumedly sporadic forms of TSE in cattle and some sporadic forms of human CJD are among the issues that need to be addressed for a careful assessment of the risk for cattle-to-human transmission of H- and L-type prions.


Spread of BSE prions in cynomolgus monkeys (Macaca fascicularis) after oral transmission

Edgar Holznagel1, Walter Schulz-Schaeffer2, Barbara Yutzy1, Gerhard Hunsmann3, Johannes Loewer1 1Paul-Ehrlich-Institut, Federal Institute for Sera and Vaccines, Germany; 2Department of Neuropathology, Georg-August University, Göttingen, Germany, 3Department of Virology and Immunology, German Primate Centre, Göttingen, Germany

Background: BSE-infected cynomolgus monkeys represent a relevant animal model to study the pathogenesis of variant Creutzfeldt-Jacob disease (vCJD).

Objectives: To study the spread of BSE prions during the asymptomatic phase of infection in a simian animal model.

Methods: Orally BSE-dosed macaques (n=10) were sacrificed at defined time points during the incubation period and 7 orally BSE-dosed macaques were sacrificed after the onset of clinical signs. Neuronal and non-neuronal tissues were tested for the presence of proteinase-K-resistant prion protein (PrPres) by western immunoblot and by paraffin-embedded tissue (PET) blot technique.

Results: In clinically diseased macaques (5 years p.i. + 6 mo.), PrPres deposits were widely spread in neuronal tissues (including the peripheral sympathetic and parasympathetic nervous system) and in lymphoid tissues including tonsils. In asymptomatic disease carriers, PrPres deposits could be detected in intestinal lymph nodes as early as 1 year p.i., but CNS tissues were negative until 3 – 4 years p.i. Lumbal/sacral segments of the spinal cord and medulla oblongata were PrPres positive as early as 4.1 years p.i., whereas sympathetic trunk and all thoracic/cervical segments of the spinal cord were still negative for PrPres. However, tonsil samples were negative in all asymptomatic cases.

Discussion: There is evidence for an early spread of BSE to the CNS via autonomic fibres of the splanchnic and vagus nerves indicating that trans-synaptical spread may be a time-limiting factor for neuroinvasion. Tonsils were predominantly negative during the main part of the incubation period indicating that epidemiological vCJD screening results based on the detection of PrPres in tonsil biopsies may mostly tend to underestimate the prevalence of vCJD among humans.


PrPSc distribution pattern in cattle experimentally challenged with H-type and L-type atypical BSE

Anne Buschmann1, Ute Ziegler1, Leila McIntyre2, Markus Keller1, Ron Rogers3, Bob Hills3, Martin H. Groschup1 1Friedrich-Loeffler-Institut, INEID, Germany; 2Faculty of Veterinary Medicine, University of Calgary, Canada; 3Health Canada, Ottawa, Canada

Background: After the detection of two novel BSE forms designated H-type and L-type BSE, the question of the pathogenesis and the agent distribution in cattle affected with these forms was fully open. From initial studies, it was already known that the PrPSc distribution in L-type BSE affected cattle differed from that known for classical BSE (C-type) where the obex region always displays the highest PrPSc concentrations. In contrast in L-type BSE cases, the thalamus and frontal cortex regions showed the highest levels of the pathological prion protein, while the obex region was only weakly involved. No information was available on the distribution pattern in H-type BSE.

Objectives: To analyse the PrPSc and infectivity distribution in cattle experimentally challenged with H-type and L-type BSE.

Methods: We analysed CNS and peripheral tissue samples collected from cattle that were intracranially challenged with Htype (five animals) and L-type (six animals) using a commercial BSE rapid test (IDEXX HerdChek), immunohistochemistry (IHC) and a highly sensitive Western blot protocol including a phosphotungstic acid precipitation of PrPSc (PTA-WB). Samples collected during the preclinical and the clinical stages of the disease were examined. For the detection of BSE infectivity, selected samples were also inoculated into highly sensitive Tgbov XV mice overexpressing bovine prion protein (PrPC).

Results: Analysis of a collection of fifty samples from the peripheral nervous, lymphoreticular, digestive, reproductive, respiratory and musculo-skeletal systems by PTA-WB, IDEXXHerdChek BSE EIA and IHC revealed a general restriction of the PrPSc accumulation to the central nervous system.

Discussion: Our results on the PrPSc distribution in peripheral tissues of cattle affected with H-type and L-type BSE are generally in accordance with what has been known for C-type BSE. Bioassays are ongoing in highly sensitive transgenic mice in order to reveal infectivity.


Title: Association of a bovine prion gene haplotype with atypical BSE


Clawson, Michael

Submitted to: Meeting Abstract Publication Type: Abstract Publication Acceptance Date: December 2, 2008 Publication Date: January 1, 2009 Citation: Clawson, M.L. 2009. Association of a bovine prion gene haplotype with atypical BSE [abstract]. Plant and Animal Genomes XVII Conference. Abstract No. W091. Available:

Technical Abstract: Transmissible spongiform encephalopathies (TSEs), also known as prion diseases, are a class of fatal neurodegenerative disorders that occur in humans, ruminants, cats, and mink. Three distinct TSEs afflict cattle: classical bovine spongiform encephalopathy (BSE), atypical H-type BSE, and atypical L-type BSE. Classical BSE was identified in the 1980s and is acquired by cattle through the consumption of feed contaminated with the infectious prion agent. Atypical BSEs have only recently been recognized as distinct cattle prion diseases and are extremely rare. The full extent of genetic susceptibilities to atypical BSEs is unknown; however, one atypical H-type case identified in the United States (2006) was most likely caused by a genetic mutation in the prion gene, E211K. We have identified an association of a bovine prion DNA haplotype with atypical BSE that is independent of E211K. The haplotype spans a portion of the prion gene that includes part of intron 2, the entire coding region of exon 3, and part of the three prime untranslated region of exon 3 (13 kb). Despite the low frequency of this haplotype among general cattle populations, it was present in a majority of H- and L-type atypical BSE cases from Canada, France, and the United States. This result indicates that there is a genetic component to atypical BSE susceptibility in addition to E211K.

I ask Professor Kong ;

Thursday, December 04, 2008 3:37 PM Subject: RE: re--Chronic Wating Disease (CWD) and Bovine Spongiform Encephalopathies (BSE): Public Health Risk Assessment

''IS the h-BSE more virulent than typical BSE as well, or the same as cBSE, or less virulent than cBSE? just curious.....''

Professor Kong reply ;


''As to the H-BSE, we do not have sufficient data to say one way or another, but we have found that H-BSE can infect humans. I hope we could publish these data once the study is complete.

Thanks for your interest.''

Best regards,

Qingzhong Kong, PhD Associate Professor Department of Pathology Case Western Reserve University Cleveland, OH 44106 USA


I look forward to further transmission studies, and a true ENHANCED BSE/atypical BSE surveillance program put forth testing all cattle for human and animal consumption for 5 years. a surveillance program that uses the most sensitive TSE testing, and has the personnel that knows how to use them, and can be trusted. I look forward to a stringent mad cow feed ban being put forth, and then strictly enforced. we need a forced, not voluntary feed ban, an enhanced feed ban at that, especially excluding blood. we need some sort of animal traceability. no more excuses about privacy. if somebody is putting out a product that is killing folks and or has the potential to kill you, then everybody needs to know who they are, and where that product came from. same with hospitals, i think medical incidents in all states should be recorded, and made public, when it comes to something like a potential accidental transmission exposure event. so if someone is out there looking at a place to go have surgery done, if you have several hospitals having these type 'accidental exposure events', than you can go some place else. it only makes sense. somewhere along the road, the consumer lost control, and just had to take whatever they were given, and then charged these astronomical prices. some where along the line the consumer just lost interest, especially on a long incubating disease such as mad cow disease i.e. Transmissible Spongiform Encephalopathy. like i said before, there is much more to the mad cow story than bovines and eating a hamburger, we must start focusing on all TSE in all species. ...TSS

Month Number of Tests

Feb 2009 -- 1,891

Jan 2009 -- 4,620


Molecular Features of the Protease-resistant Prion Protein (PrPres) in H-type BSE

Biacabe, A-G1; Jacobs, JG2; Gavier-Widén, D3; Vulin, J1; Langeveld, JPM2; Baron, TGM1 1AFSSA, France; 2CIDC-Lelystad, Netherlands; 3SVA, Sweden

Western blot analyses of PrPres accumulating in the brain of BSE-infected cattle have demonstrated 3 different molecular phenotypes regarding to the apparent molecular masses and glycoform ratios of PrPres bands. We initially described isolates (H-type BSE) essentially characterized by higher PrPres molecular mass and decreased levels of the diglycosylated PrPres band, in contrast to the classical type of BSE. This type is also distinct from another BSE phenotype named L-type BSE, or also BASE (for Bovine Amyloid Spongiform Encephalopathy), mainly characterized by a low representation of the diglycosylated PrPres band as well as a lower PrPres molecular mass. Retrospective molecular studies in France of all available BSE cases older than 8 years old and of part of the other cases identified since the beginning of the exhaustive surveillance of the disease in 20001 allowed to identify 7 H-type BSE cases, among 594 BSE cases that could be classified as classical, L- or H-type BSE. By Western blot analysis of H-type PrPres, we described a remarkable specific feature with antibodies raised against the C-terminal region of PrP that demonstrated the existence of a more C-terminal cleaved form of PrPres (named PrPres#2 ), in addition to the usual PrPres form (PrPres #1). In the unglycosylated form, PrPres #2 migrates at about 14 kDa, compared to 20 kDa for PrPres #1. The proportion of the PrPres#2 in cattle seems to by higher compared to the PrPres#1. Furthermore another PK–resistant fragment at about 7 kDa was detected by some more N-terminal antibodies and presumed to be the result of cleavages of both N- and C-terminal parts of PrP. These singular features were maintained after transmission of the disease to C57Bl/6 mice. The identification of these two additional PrPres fragments (PrPres #2 and 7kDa band) reminds features reported respectively in sporadic Creutzfeldt-Jakob disease and in Gerstmann-Sträussler-Scheinker (GSS) syndrome in humans.

Atypical BSE North America Update February 2009

Detection of Pathologic Prion Protein in the Olfactory Bulb of Natural and Experimental Bovine Spongiform Encephalopathy Affected Cattle in Great Britain

Y. H. LEE, M. M. SIMMONS, S. A. C. HAWKINS, Y. I. SPENCER, P. WEBB, M. J. STACK, AND G. A. H. WELLS National Veterinary Research and Quarantine Service, Anyang, Republic of Korea (YHL); and Veterinary Laboratories Agency, Addlestone, Surrey, United Kingdom (MMS, SACH, YIS, PW, MJS, GAHW)


To investigate the relative involvement of the olfactory region in classical bovine spongiform encephalopathy (BSE), immunohistochemical labeling of prion protein scrapie (PrPSc) was scored in the brainstem, frontal cerebral cortex, and olfactory bulb of cattle with natural and experimental clinical cases of BSE in Great Britain. The intensity of immunolabeling was greatest in the brainstem, but PrPSc was also detected in the olfactory bulb and the cerebral cortex. A diffuse, nonparticulate labeling, possibly due to abundance of cellular PrP, was consistently observed in the olfactory glomeruli of the cases and negative controls. Involvement of the olfactory bulb in BSE and other naturally occurring TSEs of animals raises speculation as to an olfactory portal of infection or a route of excretion of the prion agent.

Key words: BSE; olfactory bulb; olfactory glomeruli; PrPSc; PrPC.


Only two cases of atypical BSE have been reported from GB; both were H type and were diagnosed on molecular characterization.10 Detailed neuropathologic description of atypical BSE is limited to the L type, originally named bovine amyloidotic spongiform encephalopathy (BASE).3


In BASE, in addition to PrP-amyloid plaques in the olfactory bulb, the highest levels of PrPSc were recovered from the thalamus and olfactory regions.2 Also, in both captive and free-ranging mule deer with chronic wasting disease, the olfactory cortex has been found to be among the most severely affected areas of the brain.8 Such patterns may be solely a reflection of selective vulnerability of certain neuroanatomic loci and, in end-stage disease, a reflection of phenotype, but equally, they arouse speculation as to possible olfactory portals of infection or excretion of agent. In human transmissible spongiform encephalopathies (TSEs), PrPSc immunolabeling has been reported in the olfactory tract of a variant Creutzfeldt-Jakob disease patient, and in sporadic Creutzfeldt-Jakob disease (sCJD), selective deposition of PrPSc in olfactory glomeruli, olfactory tracts, and olfactory cortex is recorded.6 In the latter study, PrPSc was also reported in the cilia of olfactory receptor neurons and basal cells of the olfactory epithelium but not in the respiratory epithelium. Detection of PrPSc in an olfactory mucosa biopsy, performed 45 days after disease onset in a sCJD patient, led to the suggestion that the involvement of olfactory epithelium might be an early event in sCJD.6


The present study demonstrates that, in clinical cases, involvement of the olfactory lobe is a consistent phenotypic feature of classic BSE but, in contrast to BASE,3 it is not preferentially affected compared with the cerebral cortex or brainstem. In studies of the pathogenesis of classical BSE after oral exposure, infectivity has not been demonstrated in nasal mucosa,11 but it has been shown, albeit at low titer, in this tissue in clinical cases of scrapie of sheep and goats.5 The detection of PrPSc in olfactory bulb in this study and indeed in other TSEs in terminal disease suggests that olfactory pathways cannot be excluded as a secondary or ancillary route of infection.


Research Project: Study of Atypical Bse Location: Virus and Prion Diseases of Livestock

Project Number: 3625-32000-086-05 Project Type: Specific Cooperative Agreement

Start Date: Sep 15, 2004 End Date: Sep 14, 2009

Objective: The objective of this cooperative research project with Dr. Maria Caramelli from the Italian BSE Reference Laboratory in Turin, Italy, is to conduct comparative studies with the U.S. bovine spongiform encephalopathy (BSE) isolate and the atypical BSE isolates identified in Italy. The studies will cover the following areas: 1. Evaluation of present diagnostics tools used in the U.S. for the detection of atypical BSE cases. 2. Molecular comparison of the U.S. BSE isolate and other typical BSE isolates with atypical BSE cases. 3. Studies on transmissibility and tissue distribution of atypical BSE isolates in cattle and other species.

Approach: This project will be done as a Specific Cooperative Agreement with the Italian BSE Reference Laboratory, Istituto Zooprofilattico Sperimentale del Piemonte, in Turin, Italy. It is essential for the U.S. BSE surveillance program to analyze the effectiveness of the U.S diagnostic tools for detection of atypical cases of BSE. Molecular comparisons of the U.S. BSE isolate with atypical BSE isolates will provide further characterization of the U.S. BSE isolate. Transmission studies are already underway using brain homogenates from atypical BSE cases into mice, cattle and sheep. It will be critical to see whether the atypical BSE isolates behave similarly to typical BSE isolates in terms of transmissibility and disease pathogenesis. If transmission occurs, tissue distribution comparisons will be made between cattle infected with the atypical BSE isolate and the U.S. BSE isolate. Differences in tissue distribution could require new regulations regarding specific risk material (SRM) removal.




Human susceptibility to atypical scrapie

Chris Plinston, Rona Barron, Nora Hunter The Roslin Institute and R(D)SVS, University of Edinburgh, UK

Background: Isolates of classical sheep scrapie are thought to pose little risk to humans as there have been no documented links between presence of sheep scrapie and the development of human TSE disease. However, the link between BSE and the development of vCJD in humans proves that a risk does exist from ruminant TSE disease, and therefore all new ruminant TSEs may potentially be transmissible to humans. Due to increased sensitivity of TSE diagnostic assay systems, a new TSE of sheep termed ‘atypical scrapie’ has been identified. This disease has been difficult to identify, and is found mainly in sheep which are previously thought to have a genetic makeup that made them resistant to scrapie. It is unclear whether this is a new TSE of sheep, an old disease which has only been identified through increased surveillance, or if it represents the phenotype of classical scrapie in so called ‘resistant’ sheep PrP genotypes.

Objectives: The objective of the study is to assess relative transmissibility of atypical scrapie isolates to humans and the associated risk to the population.

Methods: In order to determine whether atypical scrapie poses a risk to human health we have transmitted isolates from three different sheep PrP genotypes to our gene targeted transgenic mice which express human PrP with the M129V polymorphism known to be important in human susceptibility to disease. Mice of all three PrP genotypes have been inoculated intracerebrally with atypical scrapie isolates.

Discussion: In order to prevent the emergence of a new human TSE, we need to be able to assess the risk to humans from new emerging TSEs in livestock. The study of atypical scrapie infection in these transgenic lines could therefore provide important information on the host range and disease characteristics associated with such isolates. Preventative measures could then be put in place before this disease gives rise to another human disease variant and an underlying level of infection in the population.


Parallels between different forms of sheep scrapie and types of Creutzfeldt-Jakob disease (CJD)

Wiebke M. Wemheuer1, Sylvie L. Benestad2, Arne Wrede1, Wilhelm E. Wemheuer3, Tatjana Pfander1, Bjørn Bratberg2, Bertram Brenig3,Walter J. Schulz-Schaeffer1 1University Medical Center Goettingen, Germany; 2Institute of Veterinary Medicine Oslo, Norway; 3Institute of Veterinary Medicine Goettingen, Germany

Background: Scrapie in sheep and goats is often regarded as the archetype of prion diseases. In 1998, a new form of scrapie – atypical/Nor98 scrapie – was described that differed from classical scrapie in terms of epidemiology, Western blot profile, the distribution of pathological prion protein (PrPSc) in the body and its stability against proteinase K. In a similar way, distinct disease types exist in sporadic Creutzfeldt-Jakob disease (CJD). They differ with regard to their clinical outcome, Western blot profile and PrPSc deposition pattern in the central nervous system (CNS).

Objectives: The comparison of PrPSc deposits in sheep scrapie and human sporadic CJD. Methods: Tissues of the CNS of sheep with classical scrapie, sheep with atypical/Nor98 scrapie and 20 patients with sporadic CJD were examined using the sensitive Paraffin Embedded Tissue (PET) blot method. The results were compared with those obtained by immunohistochemistry. With the objective of gaining information on the protein conformation, the PrPSc of classical and atypical/Nor98 sheep scrapie and sporadic CJD was tested for its stability against denaturation with guanidine hydrochloride (GdnHCl) using a Membrane Adsorption Assay.

Results: The PrPSc of atypical/Nor98 scrapie cases and of CJD prion type 1 patients exhibits a mainly reticular/synaptic deposition pattern in the brain and is relatively sensitive to denaturation with GdnHCl. In contrast classical scrapie cases and CJD prion type 2 patients have a more complex PrPSc deposition pattern in common that consists of larger PrPSc aggregates and the PrPSc itself is comparatively stable against denaturation.

Discussion: The similarity between CJD types and scrapie types indicates that at least two comparable forms of the misfolded prion protein exist beyond species barriers and can elicit prion diseases. It seems therefore reasonable to classify classical and atypical/Nor98 scrapie – in analogy to the existing CJD types – as different scrapie types.


Prion infectivity in milk from ARQ/ARQ sheep experimentally infected with Scrapie and MAEDI-VISNA virus

Ciriaco Ligios1, Maria Giovanna Cancedda1, Antonello Carta2, Cinzia Santucciu1 Caterina Maestrale1, Francesca Demontis1, Sonia Attene1, Maria Giovanna Tilocca1, Cristiana Patta1, Massimo Basagni5, Paola Melis1, James C. De- Martini3, Christina Sigurdson4 1Istituto Zooprofilattico Sperimentale della Sardegna, Italy; 2Research Unit: Genetics and Biotechnology, DIRPA, AGRIS Sardinia, Italy; 3Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO, USA; 4Department of Pathology, School of Medicine, University of California San Diego, USA; 5Prion Diagnostica Rho, Italy

Background: Scrapie in sheep is characterized by the deposition of misfolded and aggregated prion protein (PrPSc) in the central nervous system (CNS) and within the lymphoreticular system (LRS). PrPSc was shown to accumulate in organs beyond the CNS and the LRS when lymphofollicular or granulomatous inflammation was also present. Objectives: Our aim was to determine whether ectopic PrPSc accumulation in the inflamed mammary gland of sheep with scrapie results in infectious prion secretion into the milk.

Methods: We fed approximately 1.1 - 2.1 L of milk from sheep with lymphofollicular mastitis and clinical scrapie to each of 8 ARQ/ARQ lambs derived from scrapie-free flocks. The milk donor sheep had been previously inoculated with Maedi-Visna virus (MVV) intratracheally and intravenously and scrapie brain homogenate orally. In addition, 3 ARQ/ARQ lambs were fed approximately 1.4 – 1.7 L of milk from ARQ/ARQ sheep that had been experimentally infected with only scrapie. Additional control ARQ/ARQ lambs were inoculated with scrapie brain homogenate only, or with milk from uninfected sheep.

Results: Two lambs which had received milk from sheep with mastitis and scrapie developed clinical signs of scrapie at 677 and 745 days post-inoculation. One additional clinically healthy lamb from this group, which was sacrificed for a cause unrelated to scrapie, was found to have PrPSc in brain and tonsil. The control lambs and those which received milk from sheep affected only with scrapie are, to date, clinically healthy.

Discussion: This is the first evidence of clinical scrapie in sheep fed milk from scrapie sick sheep. The experiment is ongoing, however these preliminary results indicate that milk and/or colostrum from ARQ/ARQ sheep with clinical scrapie and lymphofollicular mastitis could contribute to scrapie transmission.


Successful oral transmission of classical scrapie to ARR/ARQ sheep

Sarah Jo Moore1, Hugh Simmons1, Timm Konold1, Glenda Dexter1, Steve Ryder2 1Veterinary Laboratories Agency, 2Home Office Animals (Scientific Procedures) Inspectorate

Background: Scrapie susceptibility in sheep is strongly influenced by allelic variation in the gene which encodes the prion protein. As part of the National Scrapie Plan (NSP) for Great Britain ram genotyping and selective breeding has been used to increase the number of sheep in the national flock that are genetically resistant to classical scrapie. According to the NSP, ARR/ARQ sheep are considered ‘genetically resistant’ to scrapie, although four field cases have been detected since 2002.

Objective: To investigate the susceptibility and pathogenesis of classical scrapie in ARR/ARQ sheep.

Methods: TSE-free lambs were dosed orally with 5g of pooled brain from scrapie clinical suspects. Timed-culls were performed at 12 and 24 months post-inoculation (mpi) then six monthly thereafter. All sheep underwent a detailed clinical examination before culling. At post-mortem 41 tissues were sampled from all major body systems. Detection of disease-associated prion protein (PrPd) in central nervous system tissues was done by immunohistochemistry (IHC), Western blot and Bio-rad elisa. All other tissues were examined by IHC only.

Results: PrPd was first detected in the LRS at 24 mpi, in the central nervous system (CNS) at 36 mpi, and in the peripheral nervous system (PNS) at 66 mpi. Throughout the time course PrPd accumulation in LRS tissues was more restricted and less severe than in CNS and PNS tissues. The first confirmed clinical case occurred at 72 mpi.

Discussion: We have shown that ARR/ARQ sheep can be infected with classical scrapie via the oral route.The pathogenesis of scrapie in ARR/ARQ sheep appears to be different to that in sheep of susceptible genotypes. While VRQ/VRQ clinical suspects have extensive LRS involvement only one LRS tissue was positive in the ARR/ARQ clinical suspect. This could suggest that infectivity had travelled to the CNS via a nongastrointestinal route. ARR/ARQ sheep may act as ‘silent carriers’ of disease. However, PrPd accumulation in the gut-associated lymphoid tissues was mild and restricted so non-faecal routes may be more important in lateral transmission from this genotype. The tissue distribution of PrPd accumulation in this study suggest that currently available ‘live tests’ for preclinical diagnosis – third eyelid and/or rectoanal mucosa-associated lymphoid tissue (RAMALT) biopsy – may be unrewarding in sheep of this genotype.

Wednesday, July 1, 2009

Nor98 scrapie identified in the United States J Vet Diagn Invest 21:454-463 (2009)


Aspects of the Cerebellar Neuropathology in Nor98

Gavier-Widén, D1; Benestad, SL2; Ottander, L1; Westergren, E1 1National Veterinary Insitute, Sweden; 2National Veterinary Institute,

Norway Nor98 is a prion disease of old sheep and goats. This atypical form of scrapie was first described in Norway in 1998. Several features of Nor98 were shown to be different from classical scrapie including the distribution of disease associated prion protein (PrPd) accumulation in the brain. The cerebellum is generally the most affected brain area in Nor98. The study here presented aimed at adding information on the neuropathology in the cerebellum of Nor98 naturally affected sheep of various genotypes in Sweden and Norway. A panel of histochemical and immunohistochemical (IHC) stainings such as IHC for PrPd, synaptophysin, glial fibrillary acidic protein, amyloid, and cell markers for phagocytic cells were conducted. The type of histological lesions and tissue reactions were evaluated. The types of PrPd deposition were characterized. The cerebellar cortex was regularly affected, even though there was a variation in the severity of the lesions from case to case. Neuropil vacuolation was more marked in the molecular layer, but affected also the granular cell layer. There was a loss of granule cells. Punctate deposition of PrPd was characteristic. It was morphologically and in distribution identical with that of synaptophysin, suggesting that PrPd accumulates in the synaptic structures. PrPd was also observed in the granule cell layer and in the white matter. The pathology features of Nor98 in the cerebellum of the affected sheep showed similarities with those of sporadic Creutzfeldt-Jakob disease in humans.

***The pathology features of Nor98 in the cerebellum of the affected sheep showed similarities with those of sporadic Creutzfeldt-Jakob disease in humans.



R. Nonno1, E. Esposito1, G. Vaccari1, E. Bandino2, M. Conte1, B. Chiappini1, S. Marcon1, M. Di Bari1, S.L. Benestad3, U. Agrimi1 1 Istituto Superiore di Sanità, Department of Food Safety and Veterinary Public Health, Rome, Italy (mhtml:%7B33B38F65-8D2E-434D-8F9B-8BDCD77D3066%7Dmid://00000164/!; 2 Istituto Zooprofilattico della Sardegna, Sassari, Italy; 3 National Veterinary Institute, Department of Pathology, Oslo, Norway

Molecular variants of PrPSc are being increasingly investigated in sheep scrapie and are generally referred to as "atypical" scrapie, as opposed to "classical scrapie". Among the atypical group, Nor98 seems to be the best identified. We studied the molecular properties of Italian and Norwegian Nor98 samples by WB analysis of brain homogenates, either untreated, digested with different concentrations of proteinase K, or subjected to enzymatic deglycosylation. The identity of PrP fragments was inferred by means of antibodies spanning the full PrP sequence. We found that undigested brain homogenates contain a Nor98-specific PrP fragment migrating at 11 kDa (PrP11), truncated at both the C-terminus and the N-terminus, and not N-glycosylated. After mild PK digestion, Nor98 displayed full-length PrP (FL-PrP) and N-glycosylated C-terminal fragments (CTF), along with increased levels of PrP11. Proteinase K digestion curves (0,006-6,4 mg/ml) showed that FL-PrP and CTF are mainly digested above 0,01 mg/ml, while PrP11 is not entirely digested even at the highest concentrations, similarly to PrP27-30 associated with classical scrapie. Above 0,2 mg/ml PK, most Nor98 samples showed only PrP11 and a fragment of 17 kDa with the same properties of PrP11, that was tentatively identified as a dimer of PrP11. Detergent solubility studies showed that PrP11 is insoluble in 2% sodium laurylsorcosine and is mainly produced from detergentsoluble, full-length PrPSc. Furthermore, among Italian scrapie isolates, we found that a sample with molecular and pathological properties consistent with Nor98 showed plaque-like deposits of PrPSc in the thalamus when the brain was analysed by PrPSc immunohistochemistry. Taken together, our results show that the distinctive pathological feature of Nor98 is a PrP fragment spanning amino acids ~ 90-155. This fragment is produced by successive N-terminal and C-terminal cleavages from a full-length and largely detergent-soluble PrPSc, is produced in vivo and is extremely resistant to PK digestion.

*** Intriguingly, these conclusions suggest that some pathological features of Nor98 are reminiscent of Gerstmann-Sträussler-Scheinker disease.


A newly identified type of scrapie agent can naturally infect sheep with resistant PrP genotypes

Annick Le Dur*,?, Vincent Béringue*,?, Olivier Andréoletti?, Fabienne Reine*, Thanh Lan Laï*, Thierry Baron§, Bjørn Bratberg¶, Jean-Luc Vilotte?, Pierre Sarradin**, Sylvie L. Benestad¶, and Hubert Laude*,?? +Author Affiliations

*Virologie Immunologie Moléculaires and ?Génétique Biochimique et Cytogénétique, Institut National de la Recherche Agronomique, 78350 Jouy-en-Josas, France; ?Unité Mixte de Recherche, Institut National de la Recherche Agronomique-Ecole Nationale Vétérinaire de Toulouse, Interactions Hôte Agent Pathogène, 31066 Toulouse, France; §Agence Française de Sécurité Sanitaire des Aliments, Unité Agents Transmissibles Non Conventionnels, 69364 Lyon, France; **Pathologie Infectieuse et Immunologie, Institut National de la Recherche Agronomique, 37380 Nouzilly, France; and ¶Department of Pathology, National Veterinary Institute, 0033 Oslo, Norway

Edited by Stanley B. Prusiner, University of California, San Francisco, CA (received for review March 21, 2005)

Abstract Scrapie in small ruminants belongs to transmissible spongiform encephalopathies (TSEs), or prion diseases, a family of fatal neurodegenerative disorders that affect humans and animals and can transmit within and between species by ingestion or inoculation. Conversion of the host-encoded prion protein (PrP), normal cellular PrP (PrPc), into a misfolded form, abnormal PrP (PrPSc), plays a key role in TSE transmission and pathogenesis. The intensified surveillance of scrapie in the European Union, together with the improvement of PrPSc detection techniques, has led to the discovery of a growing number of so-called atypical scrapie cases. These include clinical Nor98 cases first identified in Norwegian sheep on the basis of unusual pathological and PrPSc molecular features and "cases" that produced discordant responses in the rapid tests currently applied to the large-scale random screening of slaughtered or fallen animals. Worryingly, a substantial proportion of such cases involved sheep with PrP genotypes known until now to confer natural resistance to conventional scrapie. Here we report that both Nor98 and discordant cases, including three sheep homozygous for the resistant PrPARR allele (A136R154R171), efficiently transmitted the disease to transgenic mice expressing ovine PrP, and that they shared unique biological and biochemical features upon propagation in mice. These observations support the view that a truly infectious TSE agent, unrecognized until recently, infects sheep and goat flocks and may have important implications in terms of scrapie control and public health.

Monday, December 1, 2008

When Atypical Scrapie cross species barriers


Andreoletti O., Herva M. H., Cassard H., Espinosa J. C., Lacroux C., Simon S., Padilla D., Benestad S. L., Lantier F., Schelcher F., Grassi J., Torres, J. M., UMR INRA ENVT 1225, Ecole Nationale Veterinaire de Toulouse.France; ICISA-INlA, Madrid, Spain; CEA, IBiTec-5, DSV, CEA/Saclay, Gif sur Yvette cedex, France; National Veterinary Institute, Postboks 750 Sentrum, 0106 Oslo, Norway, INRA IASP, Centre INRA de Tours, 3738O Nouzilly, France.


Atypical scrapie is a TSE occurring in small ruminants and harbouring peculiar clinical, epidemiological and biochemical properties. Currently this form of disease is identified in a large number of countries. In this study we report the transmission of an atypical scrapie isolate through different species barriers as modeled by transgenic mice (Tg) expressing different species PRP sequence.

The donor isolate was collected in 1995 in a French commercial sheep flock. inoculation into AHQ/AHQ sheep induced a disease which had all neuro-pathological and biochemical characteristics of atypical scrapie. Transmitted into Transgenic mice expressing either ovine or PrPc, the isolate retained all the described characteristics of atypical scrapie.

Surprisingly the TSE agent characteristics were dramatically different v/hen passaged into Tg bovine mice. The recovered TSE agent had biological and biochemical characteristics similar to those of atypical BSE L in the same mouse model. Moreover, whereas no other TSE agent than BSE were shown to transmit into Tg porcine mice, atypical scrapie was able to develop into this model, albeit with low attack rate on first passage.

Furthermore, after adaptation in the porcine mouse model this prion showed similar biological and biochemical characteristics than BSE adapted to this porcine mouse model. Altogether these data indicate.

(i) the unsuspected potential abilities of atypical scrapie to cross species barriers

(ii) the possible capacity of this agent to acquire new characteristics when crossing species barrier

These findings raise some interrogation on the concept of TSE strain and on the origin of the diversity of the TSE agents and could have consequences on field TSE control measures.

NOR-98 ATYPICAL SCRAPIE 5 cases documented in USA in 5 different states USA 2007


Monday, September 1, 2008



Transmission of bovine-passaged TME prion strain to macaque

Emmanuel Comoy1, Juergen Richt2, Valérie Durand1, Sophie Freire1, Evelyne Correia1, Amir Hamir2, Marie- Madeleine Ruchoux1, Paul Brown1, Jean-Philippe Deslys1 1Atomic Energy Commission, France; 2National Animal Disease Center, USA

Background: The origin of Transmissible Mink Encephalopathy (TME) remains controversial, with historical evidence for either scrapie or BSE as the source of separate outbreaks. The case for BSE is supported by the experimental transmission of BSE from cattle to mink, whereas scrapie failed to transmit from sheep to mink. Transmission of TME from mink to cynomolgus macaque is inefficient, suggesting a low risk of TSE to human health. Because only typical and atypical BSE prion strains have been shown to be easily transmissible from non-primate to primate species, we have investigated transmissibility to monkeys of a cattle-passaged strain of TME.

Objectives: To compare the transmissibility of cattle-passaged TME prions to the transmissibility of other cattle-passaged prions.

Methods: Monkeys (cynomolgus macaques) were intra-cerebrally infected with classical BSE, atypical BSE strains (BASE and BSE H), and a cattle-passaged TME strain. Animals were regularly monitored for clinical signs, and extensive biochemical and immunohistochemical studies were performed on lymphoid and neural tissues of animals that have already died.

Results and discussion: The animal infected with the cattlepassaged TME strain developed neurological clinical signs after a very short incubation period of 20 months, with a clinical picture that is clearly different from that of BSE/vCJD-infected animals, but similar to that of BASE (the animal is still alive at the time of this writing but post-mortem histopathological and immunohistochemical analyses will provide a more complete characterization of the disease). This new transmission reinforces the notion of human vulnerability to prion diseases passaged through cattle, perhaps due to a low species barrier.

Saturday, December 01, 2007

Phenotypic Similarity of Transmissible Mink Encephalopathy in Cattle and L-type Bovine Spongiform Encephalopathy in a Mouse Model

Tuesday, July 21, 2009

Transmissible mink encephalopathy - review of the etiology Folia Neuropathologica 2/2009


Recent results on the transmission, detection, and pathogenesis of chronic wasting disease

Edward A. Hoover1, Nicholas J. Haley1, Candace K. Mathiason1, Nathanial D. Denkers1, Davis M. Seelig1, and Glenn C. Telling2 1Colorado State University, USA; 2University of Kentucky, Lexington, USA

Background: Chronic wasting disease (CWD) of cervids is distinguished by its high level of transmissibility. We have previously shown that body fluids and excretions contain infectious CWD prions. The precise means by which these prions may access, traffick and cause disease in cervids (or other species) remains to be elucidated. Here we present current results of studies employing cervid and cervidized mouse bioassays and serial protein misfolding cyclic amplification (sPMCA) to address these questions.

Objectives: We sought to determine: (1) which components of blood and saliva carry prion infectivity; (2) whether long term, very low level CWD infection undetectable by conventional assays may exist in cervids; (3) whether CWD can be transmitted via aerosol or minor oral lesions; and (4) potential alternate pathways of CWD prion entry and dissemination exist in vivo.

Methods: The studies described utilized cervid and cervid-PrPexpressing transgenic mouse bioassays, serial protein misfolding cyclic amplification (sPMCA), and high resolution immunostaining.

Results: We present data to demonstrate: (1) localization of infectious CWD prions chiefly to the circulating CD21-expressing B/DC cell fractions of blood; (2) very low level subclinical CWD infection in cervids detectable by sPMCA and bioassay; (3) CWD transmission by aerosol and minor oral epithelial lesions; and (4) evidence of villous autonomic neural uptake and dissemination of PrPCWD.

Discussion: These findings contribute insights into CWD prion transmission, trafficking, and dissemination. The results also help direct efforts toward ante-mortem detection of CWD in cervids and raise interesting questions regarding duration of sub-clinical prion infection in cervids or other species.


Prions in feces of asymptomatic deer

Gültekin Tamgüney1,2, Michael W. Miller3, Lisa L. Wolfe3, Tracey M. Sirochman3, David V. Glidden4, Christina Palmer 1, Azucena Lemus5, Stephen J. DeArmond5, Stanley B. Prusiner1,2 1Institute for Neurodegenerative Diseases, University of California, San Francisco, USA; 2Department of Neurology, University of California, San Francisco, USA; 3Colorado Division of Wildlife, Wildlife Research Center, Fort Collins, USA; 4Department of Epidemiology and Biostatistics, University of California, San Francisco, USA; 5Department of Pathology, University of California, San Francisco, USA

Background: Chronic wasting disease (CWD) of several species in the deer family and scrapie of sheep are infectious prion diseases that are transmitted naturally within affected host populations. Even though several potential sources of infectivity have been identified in secretions and excretions from symptomatic animals, the biological importance of these sources in sustaining epidemics remains unclear.

Objective/Methods: Feces from mule deer (Odocoileus hemionus) were periodically collected before and after oral inoculation with CWD prions until the deer developed clinical signs of CWD. Fecal samples were irradiated and intracerebrally inoculated into transgenic mice overexpressing cervid PrP. Results: We report that asymptomatic CWD-infected mule deer excrete CWD prions in their feces long before they develop clinical signs of prion disease. Intracerebral inoculation of irradiated deer feces into transgenic mice overexpressing cervid PrP revealed infectivity in 14 of 15 fecal samples collected from 5 deer at 7–11 months before the onset of neurological disease. Even though prion concentrations in deer feces were much lower than those in brain tissue from the same deer collected at the disease terminus, the estimated total infectious dose excreted in feces by an infected deer over the disease course may approximate the total contained in brain tissue.

Discussion: Fecal prion excretion over long periods of time by infected deer provides a likely natural mechanism that may explain the high incidence and efficient horizontal transmission of CWD within deer herds, as well as prion transmission among susceptible cervid species.


Detection of subclinical CWD infection in conventional test-negative deer long after oral exposure to urine and feces from CWD+ deer

Nicholas Haley1, Candace Mathiason1, Mark Zabel1, Glenn Telling2, Edward Hoover1 1Colorado State University, USA; 2University of Kentucky, USA

Background: Chronic wasting disease (CWD) of cervids is distinguished by its high level of transmissibility, wherein bodily fluids and excretions are thought to play an important role. Using cervid bioassay and established CWD detection methods, we have previously identified infectious prions in saliva and blood but not urine or feces of CWD+ donors. More recently, we were able to identify very low concentrations of CWD prions in urine of deer by cervid PrP transgenic (Tg[Cer- PrP]) mouse bioassay and serial protein misfolding cyclic amplification (sPMCA).

Objectives: In these experiments, we sought to investigate whether deer previously exposed orally to urine and feces from CWD+ deer, while conventional test-negative, may actually be harboring very low level CWD infection, not evident in the 19 month observation period in the previous studies. Methods: Brain and lymph nodes from conventional test-negative deer were reanalyzed for CWD prions by sPMCA and cervid transgenic mouse bioassay in parallel with appropriate tissue-matched positive and negative controls.

Results: PrPres was detected in tissues of exposed deer by both sPMCA and Tg[CerPrP] mouse bioassay; each assay revealed very low levels of CWD prions previously undetectable by western blot, ELISA, or IHC. D

iscussion: The finding of subclinical infection in deer orally exposed to urine and feces (1) suggests that a prolonged subclinical state can exist such that observation periods in excess of two years may be needed to detect CWD infection and (2) illustrates the sensitive and specific application of sPMCA in the diagnosis of low level prion infection.


Minor oral lesions facilitate CWD infection

Nathaniel Denkers1, Glenn Telling2, Edward Hoover1 1Colorado State University, USA; 2University of Kentucky, USA

Background: While the exact mechanisms of chronic wasting disease (CWD) prion transmission, entry, and trafficking remain incompletely elucidated, transmission by exposure of the oral and/or nasal mucous membranes seems certain. As part of foraging, cervids likely experience minor lesions in the oral mucous membranes; these could have impact on susceptibility to prion entry and subsequent infection.

Objectives: To explore this potential co-factor, we used cervid PrP transgenic mice to assess whether or not micro-abrasions to the tongue may enhance susceptibility to oral CWD infection.

Methods: Two sets of FVB mice transgenically expressing the normal cervid PrPC protein [Tg(cerPrP) mice], with or without abrasions on the lingual mucosa, were inoculated orally with 10ìl of a 10% w/v brain homogenate from either CWD-positive or negative deer. Abrasions were created by lightly scratching the dorsal lingual epithelium with a 30g needle. Cohorts were sacrificed at 1, 2, 12, 52, 78, and 104 weeks post inoculation (pi) or when signs of neurologic disease were observed. Tongue, lymphoid tissue, and the brain were assessed by western blotting and immunohistochemistry to detect the CWD abnormal prion protein (PrPCWD).

Results: Between 296 and 430 dpi, 8 of the 9 CWD-inoculated mice with lingual lesions developed clinical signs of neurologic dysfunction mandating euthanasia. The brains of all 8 mice were positive by western blot and immunohistochemistry for PrPCWD. Conversely, all mice without oral lesions remain asymptomatic at >450 dpi. No evidence of PrPCWD was detected in any Tg(cerPrP) mice examined at any of the preterminal time points.

Discussion: Micro-abrasions to the lingual surface substantially facilitate CWD transmission, suggesting a co-factor that may be significant in foraging cervids or other species. Earlier post-inoculation sampling intervals (1 and 4 hours) are in progress in an attempt to determine when and where PrPCWD might be detectable after oral mucosal exposure.


Aerosol and intranasal transmission of CWD

Nathaniel Denkers1, Glenn Telling2, Edward Hoover1 1Colorado State University, USA; 2University of Kentucky, USA

Background: Little is known regarding the potential risk posed by aerosolized prions. Chronic wasting disease (CWD) prions are present in saliva and urine of infected animals and it is clearly established that CWD is transmitted horizontally, almost surely by mucosal exposure. However, the potential transmissibility of CWD by aerosol or nasal routes is not known.

Objectives: The present study was therefore designed to determine whether CWD prions are transmissible by these routes of exposure using the cervid PrP transgenic mouse model of CWD infection.

Methods: FVB mice transgenically expressing the normal cervid PrPC protein [Tg(cerPrP) mice] were exposed to CWD prions by either nose-only exposure to an aerosol generated by nebulizing 0.5 ml of a 5% w/v CWD+ brain homogenate or 10ƒÊl of a 10% w/v CWD+ brain homogenate by dropwise instillation into the nostrils. Mice were monitored for signs of clinical disease for up to 755 days post inoculation (dpi). Nasal mucosa, vomeronasal organ, lymphoid tissue, and the brain were assessed for PrPCWD by western blotting and immunohistochemistry.

Results: Six of 7 aerosol-exposed Tg(cerPrP) mice developed clinical signs of neurologic dysfunction between 411 and 749 dpi mandating euthanasia. In all symptomatic mice CWD infection was confirmed by histopathologic lesions and detection of PrPCWD within the brain. Two of 9 IN-inoculated Tg(cerPrP) mice also developed TSE between 417 and 755 dpi, again confirmed by PrPCWD detection within the brain. No evidence of PrPCWD was detected in any Tg(cerPrP) mice examined at any of the pre-terminal time points.

Discussion: CWD is transmissible by aerosol as well as intranasal exposurePpotentially implicating exposure via the respiratory system in CWD and potentially other prion diseases. Studies examining very early post-inoculation sampling intervals (1 and 4 hours) are in progress in an attempt to determine initial prion targeting and entry portals.


Adaptation of chronic wasting disease (CWD) into hamsters: evidence of a novel strain of CWD

Chad Johnson1, Debbie McKenzie2 1University of Wisconsin-Madison, USA, 2University of Alberta, Canada

Background: Prion strains are well-characterized for scrapie and BSE. Little is known about the potential for strains in chronic wasting disease (CWD). Different CWD strains could have different patterns of shedding infectious agent as well as differential detectiblility and interspecies transmissibility.

Objectives: We identified prion protein variants in whitetailed deer populations and demonstrated that Prnp genotype affects the susceptibility/disease progression of white-tailed deer to CWD. Cervid prion protein variants raise the likelihood of distinct CWD strains. We hypothesize that the prion protein variability results in different PrPCWD conformers producing different CWD strains upon interspecies transmission.

Methods: Hamsters were intracerebrally inoculated with brain homogenate or phosphotungstate concentrated preparations from CWD positive hunter-harvested (Wisconsin CWD endemic area) and from experimentally infected deer with known Prnp genotypes.

Results: Primary passage of concentrated CWD agent resulted in clinical disease at approximately 1 year post-infection. Subclinical infection was established with the other primary passages based on the detection of PrPCWD in the brains of hamsters and the successful disease transmission upon second passage. Second and third passage resulted in a decrease in incubation period to approximately 280 days. Inocula from deer with wt/wt and wt/G96S Prnp genotypes did not result in any differences in incubation period or clinical symptoms.

Discussion: Inocula from deer with the wt/wt and wt/G96S prion proteins resulted in similar disease upon transmission to hamsters, likely due to the presence of the wt prion protein. Comparison of the incubation period and clinical symptoms of the hamsters infected with inocula from Wisconsin whitetailed deer to transmission studies using different CWD inocula (Western white-tailed deer; elk and mule deer; Raymond et al. 2007) indicates that the CWD agent present in US Midwest is different from the strain(s) present in the endemic region of the western US.


Survival and limited spread of TSE infectivity after burial for one year

Robert Somerville, Karen Fernie, Allister Smith University of Edinburgh, UK

Background: Scrapie and Chronic Wasting Disease appear to spread via environmental routes, although there is little evidence that BSE or CJD do. Nevertheless there are concerns about reservoirs of BSE infection remaining in the environment after carcass burial or waste disposal.

Objectives: We are determining the survival and migration of TSE infectivity when buried for up to five years in two soil types; and either buried within bovine skulls, or as a point source bolus of TSE infected brain.

Methods: Two demonstration experiments have been set up. In one experiment boluses of TSE infected mouse brain (301V strain) have been buried in lysimeters containing either a sandy soil or a clay soil. Migration from the boluses is being assessed from soil cores taken from the lysimeters over time and assayed for TSE infectivity. In the other experiment ten bovine heads have been spiked with TSE infected mouse brain (301V strain) and buried in the two soil types. Two heads are exhumed annually and assessed for residual infectivity within and around them.

Results: After one year very small amounts of infectivity have been detected 25cm from the point source bolus in both soils. No infectivity was detected up to 9 months after burial. In the other experiment brain-like tissue was still apparent within the crania after one year. Large amounts of TSE infectivity were detected from samples of the intracranial contents, and also detected in very small amounts in soil samples in the soil immediately surrounding the heads.

Discussion: These data show that TSE infectivity can survive burial for up to a year but migrates very slowly in these soils. Results from future years will likely further illustrate the long term survival and migration properties of these infective agents. Risk assessments of TSE infectivity in the environment should take into account the likely long survival rate of foci of infectivity when large amounts of infected material have been buried.

please note not only first passage, but also second passage of CWD transmission studies to cattle, and please see attack rate ;

Interpretive Summary: This study reports findings assessing susceptibility of cattle to infection following direct surgical inoculation of the transmissible spongiform encephalopathy (TSE), chronic wasting disease (CWD, from white tailed deer) into the brain of 14 cattle. Three-month-old calves were inoculated with the CWD agent from white tailed deer. Two non-inoculated calves served as controls. Within 26 months post inoculation, 12 inoculated animals had lost weight, revealed abnormal clinical signs, and were euthanatized. Laboratory tests revealed the presence of a unique pattern of the disease agent in tissues of these animals. These findings demonstrate that when CWD is directly inoculated into the brain of cattle, 86% of inoculated cattle develop clinical signs of the disease. ...

see full text ;

see also;

Vet Pathol 44:487-493 (2007) © 2007 American College of Veterinary Pathologists

Susceptibility of Cattle to First-passage Intracerebral Inoculation with Chronic Wasting Disease Agent from White-tailed Deer A. N. Hamir, J. M. Miller, R. A. Kunkle, S. M. Hall and J. A. Richt National Animal Disease Center, ARS, USDA, Ames, IA (ANH, JMM, RAK, JAR), Pathobiology Laboratory, National Veterinary Services Laboratories, Ames, IA (SMH)

Fourteen, 3-month-old calves were intracerebrally inoculated with the agent of chronic wasting disease (CWD) from white-tailed deer (CWDwtd) to compare the clinical signs and neuropathologic findings with those of certain other transmissible spongiform encephalopathies (TSE, prion diseases) that have been shown to be experimentally transmissible to cattle (sheep scrapie, CWD of mule deer [CWDmd], bovine spongiform encephalopathy [BSE], and transmissible mink encephalopathy). Two uninoculated calves served as controls. Within 26 months postinoculation (MPI), 12 inoculated calves had lost considerable weight and eventually became recumbent. Of the 12 inoculated calves, 11 (92%) developed clinical signs. Although spongiform encephalopathy (SE) was not observed, abnormal prion protein (PrPd) was detected by immunohistochemistry (IHC) and Western blot (WB) in central nervous system tissues. The absence of SE with presence of PrPd has also been observed when other TSE agents (scrapie and CWDmd) were similarly inoculated into cattle. The IHC and WB findings suggest that the diagnostic techniques currently used to confirm BSE would detect CWDwtd in cattle, should it occur naturally. Also, the absence of SE and a distinctive IHC pattern of CWDwtd and CWDmd in cattle suggests that it should be possible to distinguish these conditions from other TSEs that have been experimentally transmitted to cattle.


Key words: Cattle; chronic wasting disease; prion diseases; prion protein immunohistochemistry; prion protein Western blot; spongiform encephalopathy.

Request reprints from Dr. A. N. Hamir, National Animal Disease Center, ARS, USDA, 2300 Dayton AvenuePO Box 70, Ames, IA 50010 (USA). E-mail: mhtml:%7B33B38F65-8D2E-434D-8F9B-8BDCD77D3066%7Dmid://00000164/!



This study used the intracerebral route of inoculation to provide the most efficient means of testing the absolute susceptibility of cattle to the agent of CWD from white-tailed deer and to provide a comparison with similarly designed previous studies.2-5,7 Such studies do not inform on susceptibility by natural routes of transmission but, if negative, can provide evidence supporting the existence of a considerable species barrier. In instances of successful transmission they also provide an understanding of the descriptive pathology that might characterize the natural disease in the recipient species.

CWD, like all other TSEs, is characterized by a long incubation period, which in deer is seldom less than 18 months.15,16 In an experimental study of cattle inoculated intracerebrally with CWD from mule deer (first passage; CWDmd), PrPd was demonstrated in only 5 of 13 cattle (38%), after incubation periods that ranged from 23 to 63 MPI.4,5 In contrast, 12 of 14 inoculated cattle in the present study were positive for PrPd (86% attack rate) within 26 MPI (21.5 ± 0.5 MPI). The increased incidence and shorter incubation periods indicate that the CWDwtd inoculum was more pathogenic in cattle than the CWDmd inoculum on first passage.4,5 However, there may be several reasons for these differences, such as genetic variability of the recipient hosts, the differences in PrP genotype of pooled brain material in the inoculum, and the infectivity titer of the inocula used in the CWD transmission studies of cattle.4,5 Regarding the latter, in a separate study of intracerebral CWD inoculation of white-tailed deer, we found both sources of CWD (from mule deer and white-tailed deer) successfully transmitted to each of two groups of white-tailed deer within two years, and there was no significant difference in incubation times and lesions between the groups (Kunkle et al., unpublished data).

In cervids, clinical CWD is characterized by emaciation, changes in behavior, and excessive salivation.15,16 Although the latter was not observed in the CWDwtd-inoculated cattle, 12 of 14 inoculated calves showed anorexia and considerable weight loss, and the majority of these cattle also showed intermittent abnormal CNS signs. However, despite the advanced clinical signs in the affected cattle, none of the animals had histopathologic changes of SE, but all were positive for PrPd by IHC and WB. The absence of morphologic lesions in cattle with cross-species transmitted TSEs has been documented previously with cattle inoculated intracerebrally with the sheep scrapie agent.3 In that study, 100% of cattle succumbed to the disease between 14 and 18 months after inoculation with a US strain of the scrapie agent derived from sheep. None of the cattle showed microscopic lesions, and all were positive for PrPd. A similar lack of morphologic changes was observed in cattle inoculated with CWDmd, even after the second passage.4,5,8

The predominant characteristics of IHC reactivity reported previously for cattle inoculated with mule deer CWD4,5,7 were also observed in the diseased cattle that died after inoculation with CWD from white tailed-deer. The PrPd accumulations were primarily multifocal and presumably glial cell-associated, with no evidence of intraneuronal or perineuronal labeling. The only difference noted between calves inoculated with CWDmd and CWDwtd was that the latter seemed to show more extensive labeling, both in amount and anatomic distribution within the CNS. In addition, labeling of white matter was more prominent in the CWDwtd-inoculated calves.

In this and in the earlier study of CWDmd in cattle,4,5 IHC labeling differed from that seen in cattle with bovine spongiform encephalopathy (BSE) or experimental transmissible mink encephalopathy (TME).6 In both (BSE and TME) the IHC labeling was similar and was characterized by widespread diffuse (usually perineuronal) labeling of grey matter neuropil, with labeled particles that were not cell-associated except occasionally at neuronal cell membranes.5,14 The IHC pattern in bovine CWD also contrasts markedly with that seen in scrapie-inoculated cattle, in which intracytoplasmic labeling of neurons was a prominent feature.2,3

Compared with experimental TME in cattle,7 the experimental bovine CWD in this study was associated with less extensive IHC labeling in neural tissues other than brain and spinal cord. Whereas the retina was positive in all cattle inoculated with TME, none of the CWD-infected cattle in this experiment had any retinal labeling. Similarly, in the present study there was no labeling in the pituitary gland, a tissue that in some TME-infected cattle is positive.7 The different affinities of tissues may reflect different abilities of these agents to amplify in these tissues. However, given sample sizes and uncontrolled experimental variables, other features, including host genetics, titers of inocula, and stage of disease cannot be excluded.

IHC labeling for PrPd was not observed in striated muscles (heart, tongue, masseter, diaphragm) of the experimental calves. This observation is in accordance with our previous findings9 in which striated muscle from 20 animals (cattle, sheep, elk, and raccoons) was examined for PrPd by IHC. In these animals, all of which had developed a TSE after experimental inoculation, PrPd was found by IHC examination in the CNS, but not in striated muscle. However, recent investigations with an enriched WB technique12 have enabled us to detect PrPd in the tongues of some sheep and elk that were experimentally inoculated with scrapie and CWD, respectively (Bessen et al., unpublished data).

When brainstems of CWD-infected cattle were analyzed by WB for the presence of PrPd, 12 of 14 samples were found to be positive for PrPd (Table 1; Fig. 3), showing a clear reaction with the three protease resistant polypeptide isoforms (di-, mono-, and unglycosylated). Interestingly, No. 3, which was found by IHC to be negative in the obex area, but positive in midbrain region (Table 2), was found positive by WB (Fig. 3). This might indicate that the WB technique used for these studies could be more sensitive than the IHC method applied. However, this difference could also be attributable to the sampling of different portions of obex used for IHC and WB analyses. The WB molecular mass was similar in all cattle inoculated with CWDwtd and similar to that of cattle-passaged CWDmd (Fig. 3). However, PrPd isoforms from deer infected with CWDwtd had a higher molecular mass (Fig. 3).

This study indicates a high susceptibility of cattle to the CWDwtd agent by the most direct route of inoculation of the CNS, but it remains to be shown if natural routes of exposure would result in infection and disease and whether differences in attack rates and incubation periods between cattle inoculated with CWDmd and CWDwtd agents reflect true differences in susceptibility or are attributable to differences in experimental factors.

Although susceptibility of cattle to intracerebral inoculation of CWDwtd was demonstrated, it should be noted that this is an unnatural route, and it suggests only a potential for cattle to become infected under natural conditions of exposure. It is likely that transmission of CWD to cattle by a more natural route, such as per os, would require a much larger dose of inoculum and might even be difficult to accomplish within the normal life span of the animal. Because the present study resulted in a higher attack rate and shorter incubation periods than similar inoculation with CWDmd, the CWDwtd agent would be the initial choice for experimental oral inoculation of cattle.

Further transmission studies of CWD isolates (e.g., CWD of elk or moose in cattle) are required to explore possible differences in clinicopathologic features that might indicate different disease phenotypes, which may in turn, reflect different CWD agent strains.

Finally, the findings of this study suggest that diagnostic techniques presently used for confirming BSE (IHC and WB) would also detect CWDmd and CWDwtd in cattle should it occur naturally.

Vet Pathol 44:487--493 (2007) Susceptibility of Cattle to First-passage Intracerebral Inoculation with Chronic Wasting Disease Agent from White-tailed Deer A. N. HAMIR,J. M. MILLER,R. A. KUNKLE,S. M. HALL,ANDJ. A. RICHT National Animal Disease Center, ARS, USDA, Ames, IA (ANR, JMM, RAK, JAR); and Pathobiology Laboratory, National Veterinary Services Laboratories, Ames, IA (SMR)

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Research Project: Transmission, Differentiation, and Pathobiology of Transmissible Spongiform Encephalopathies Location: Virus and Prion Research Unit

Title: Susceptibility of Cattle to First-Passage Intracerebral Inoculation with Chronic Wasting Disease Agent from Elk


Greenlee, Justin Nicholson, Eric Kunkle, Robert Hamir, Amirali

Submitted to: American College of Veterinary Pathologists Meeting Publication Type: Abstract Publication Acceptance Date: July 12, 2009 Publication Date: N/A

Technical Abstract: Cattle could be exposed to chronic wasting disease (CWD) from infected farmed or free-ranging cervids. The purpose of this study was to assess the transmissibility of CWD derived from elk to cattle. Intracerebral inoculation of calves (n=14) of approximately 3 months of age was done with 1 ml of a 10% brain homogenate derived from farmed elk with CWD to determine the potential for transmission and define the clinicopathologic features of disease. Non-inoculated calves (n=5) were maintained as controls. Cattle were observed twice daily and necropsies were performed as clinical signs occurred or at the termination of experiment (49 months). Clinical signs of poor appetite, weight loss, circling and bruxism occurred in two cattle (14%) at 16 and 17 months post-inoculation, respectively. The rate of transmission was lower than in cattle inoculated with CWD derived from mule deer (38%) or White-tailed deer (86%). Accumulation of abnormal prion protein (PrPd) in these cattle was confined to the central nervous system and was similar in distribution to cattle inoculated with CWD from mule deer with the most prominent immunoreactivity in midbrain, brainstem, and hippocampus with lesser immunoreactivity in the cervical spinal cord. Additional studies are required to fully assess the potential for cattle to develop CWD through a more natural route of exposure, but a low rate of transmission after intracerebral inoculation suggests that risk of transmission through other routes is low.



Published by Elsevier Ltd.

Experimental Second Passage of Chronic Wasting Disease (CWDmule deer) Agent to Cattle

A.N. Hamir, R.A. Kunkle, J.M. Miller, J.J. Greenlee and J.A. Richt

Agricultural Research Service, United States Department of Agriculture, National Animal Disease Center, 2300 Dayton Avenue, P.O. Box 70, Ames, IA 50010, USA

Received 4 April 2005; accepted 23 July 2005. Available online 18 January 2006.

Summary To compare clinicopathological findings in first and second passage chronic wasting disease (CWDmule deer) in cattle, six calves were inoculated intracerebrally with brain tissue derived from a first-passage CWD-affected calf in an earlier experiment. Two uninoculated calves served as controls. The inoculated animals began to lose both appetite and weight 10-12 months later, and five subsequently developed clinical signs of central nervous system (CNS) abnormality. By 16.5 months, all cattle had been subjected to euthanasia because of poor prognosis. None of the animals showed microscopical lesions of spongiform encephalopathy (SE) but PrPres was detected in their CNS tissues by immunohistochemistry (IHC) and rapid Western blot (WB) techniques. Thus, intracerebrally inoculated cattle not only amplified CWD PrPres from mule deer but also developed clinical CNS signs in the absence of SE lesions. This situation has also been shown to occur in cattle inoculated with the scrapie agent. The study confirmed that the diagnostic techniques currently used for diagnosis of bovine spongiform encephalopathy (BSE) in the US would detect CWD in cattle, should it occur naturally. Furthermore, it raised the possibility of distinguishing CWD from BSE in cattle, due to the absence of neuropathological lesions and to a distinctive multifocal distribution of PrPres, as demonstrated by IHC which, in this study, appeared to be more sensitive than the WB technique.

Keywords: cattle; chronic wasting disease (CWD); deer; transmissible spongiform encephalopathy (TSE)


Discussion CWD, like all other TSEs, is characterized by a long incubation period, which in deer is seldom less than 18 months (Williams and Young, 1992). In an experimental study of cattle inoculated intracerebrally with CWD from mule deer (first passage), amplification of PrPres was demonstrated in only five of 13 (38%) cattle, after incubation periods that ranged from 23 to 63 months (Hamir et al., 2001a, 2005a). In contrast, all inoculated cattle in the present study were positive for PrPres within 16.5 months. This increased attack rate with shorter incubation periods probably indicates adaptation of the CWDmule deer agent to a new host. It could also be argued that the inoculum used for the primary passage (Hamir et al., 2001a, 2005a) had a lower infectivity titre than that used for the second passage. However, the former successfully transmitted CWD to each of five white tailed deer within two years of intracerebral inoculation (Kunkle et al., Unpublished).

In cervids, clinical CWD is characterized by emaciation, changes in behaviour, and excessive salivation (Williams and Young, 1992). Although the latter was not observed in the CWD inoculated cattle, all animals showed anorexia and considerable weight loss. Five cattle also showed intermittent neurological signs. Although none of these animals showed histopathological changes in the brain, all were shown to be positive for PrPres by the IHC and WB methods. The presence of isolated vacuoles in the red nucleus is regarded as an incidental finding in cattle (McGill and Wells, 1993). The uniform susceptibility, relatively short incubation, and absence of microscopical lesions in cattle given CWD brain material passaged once through cattle resembled findings in cattle inoculated intracerebrally with the scrapie agent (Cutlip et al., 1997). In that experiment, 100% of cattle died 14-18 months after inoculation with material from the first cattle-passage of a US strain of the scrapie agent; none showed microscopical lesions and all were positive for PrPres. In the present experiment, the possibility that the PrPres seen in tissue sections represented residual CWD material from the inoculum was ruled out because of the multifocal distribution of

PrPres throughout the brain (excluding cerebellar folia) and cervical spinal cord of most of the affected animals. Had the PrPres represented residual inoculum, it would probably have been confined to the sites of deposition in the midbrain or cerebrum. Moreover, in studies on sheep scrapie, Hamir et al. (2002) showed that intracerebrally inoculated brain material containing PrPres was present for only a few days in sufficient quantity to be detectable immunohistochemically. The present work confirms previous observations that PrPres IHC labelling in cattle inoculated with the mule deer CWD agent is multifocal and glial cell-associated. This unusual pattern was first reported in descriptions of the primary CWD transmission to cattle (Hamir et al., 2001a, 2005a), and the study described here showed that it was maintained through the second passage in cattle. Further studies now in progress will determine whether this feature also characterizes CWD transmission to cattle fromother cervid species other than mule deer, namely, white tailed deer and elk. In this and an earlier study of CWD in cattle (Hamir et al., 2001a), IHC labelling differed from that seen in cattle with BSE or experimental transmissible mink encephalopathy (TME), both of which are associated with widespread diffuse labelling of grey matter neuropil, with labelled particles that are not obviously cell-associated except occasionally at neuronal cell membranes (Wells and Willsmith, 1995; Hamir et al., 2005a). The IHC pattern in bovine CWD also contrasts markedly with that seen in scrapie-inoculated cattle, in which intracytoplasmic labelling of neurons is a prominent feature (Cutlip et al., 1994, 1997). When brainstems of CWD-infected cattle were analysed by WB for the presence of PrPres, only three of six samples were found to be positive (Table 1). In contrast, all samples from the midbrain area were positive by this technique (Table 1; Fig. 5). It was noteworthy, however, that both brainstem and midbrain sections of all animals infected with CWD gave positive IHC results (Table 1) and a positive WB was associated with strong IHC labelling. This may indicate that the IHC procedure is more sensitive than the WB method for cattle-passaged CWD. However, given the multifocal nature of PrPres distribution in the CNS of CWD-infected cattle, this result is not surprising. WB analysis requires a small sample of brain tissue (e.g. 0.2 g, as in the present study) to produce a 10% homogenate; approximately 10 ml (1 mg brain tissue equivalent) of this homogenate are loaded on to an SDS-PAGE gel for further

analysis. Bearing in mind the multifocal pattern of PrPres distribution, the brain tissue used for the preparation of WB homogenate, unlike the large amount examined in the IHC procedure, might well contain few if any foci of PrPres deposition, whereas the larger piece of tissue section used for IHC may contain detectable PrPres. In this respect, therefore, the IHC method would seem preferable to the WB procedure and to other procedures (e.g. ELISA-based tests) in which only small amounts of tissue are used for analysis. In comparison with experimental TME in cattle (Hamir et al., 2005b), the experimental bovine CWD in this study was associated with less extensive IHC labelling in non-CNS (i.e. other than brain and spinal cord) neural tissues. Whereas the retina was positive in all cattle inoculated with TME, none of the CWD-infected cattle in this experiment had any retinal labelling. Similarly, in the present study there was no labelling in the pituitary gland, a tissue sometimes positive in TME-infected cattle. Because the incubation time for second passage CWD transmission (mean of 468 days) was only slightly longer than for TME (mean of 430 days), it seems likely that these different tissue affinities reflect a biological difference between these two TSE agents. PrPres IHC labelling was not observed in striated muscles (heart, tongue, masseter, diaphragm) of the experimental animals. This observation accorded with our previous findings (Hamir et al., 2004a) in which striated muscle tissues from 20 animals (cattle, sheep, elk and raccoons) were examined for PrPres. In these animals, all of which had developed a TSE after experimental inoculation, PrPres was found by IHC examination in the brains, but not in muscle tissues. However, recent investigations with an enriched WB technique (Mulcahy et al., 2004) have enabled us to detect PrPres in the tongues of some sheep and elk experimentally inoculated with scrapie and CWD, respectively. This technique failed, however, to detect PrPres in cattle inoculated with CWD or TME (Bessen et al., unpublished). This study is still in progress, and the tongues of TSE-infected animals are currently being tested after careful removal from the carcasses to ensure non-contamination with infected brain material. The present study and a previous experiment (Hamir et al., 2005a) have established the biological characteristics of the CWDmule deer agent in cattle. However, isolates of CWD from other cervids (e.g. CWDwhite-tailed and CWDelk) may differ. Transmission experiments with different CWD isolates are therefore needed to examine the possibility of variation in the CWD agent in wild cervids. Such experiments have recently been initiated at the National Animal Disease Center (NADC). Acknowledgments We thank Dr Katherine I. O'Rourke for providing the antibody for the IHC procedure. Martha Church, Kevin Hassall, Dennis Orcutt, Jean Donald, Sharla Van Roekel, and animal handlers at the NADC provided expert technical assistance. This study was carried out under the guidelines of the institutional Animal Care and Use committee at NADC. Mention of trade names or commercial products in this article is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the United States Department of Agriculture.




Susceptibility of Domestic Cattle to Chronic Wasting Disease by Oral Inoculation and Natural Exposure: Final Phase of a 10-year Study

Elizabeth S. Williams1, Donal O'Toole1, Matthew M. Hille1, Donald L. Montgomery1, Jean E. Jewell1*, Terry J. Kreeger2, and Michael W. Miller3 1Department of Veterinary Sciences, University of Wyoming, Laramie, WY 82070 2Wyoming Game and Fish Department, Wheatland, WY 82201 3Colorado Division of Wildlife, Fort Collins, Colorado 80526 *Corresponding author e-mail: mhtml:%7B33B38F65-8D2E-434D-8F9B-8BDCD77D3066%7Dmid://00000164/! The risk of domestic cattle developing a transmissible spongiform encephalopathy (TSE) after oral inoculation followed by a long incubation period, or by long-term natural exposure to cervids infected with chronic wasting disease (CWD) was studied. Ten cattle were given large oral doses of pooled brain material from CWD-infected mule deer in late August 1997 and housed in isolation at the Wyoming State Veterinary Laboratory until September 2007. Two additional groups of cattle were penned outdoors with CWD-infected deer and elk or in CWD-contaminated premises at Colorado Division of Wildlife (n=11) and Wyoming Game and Fish Department (n=10) research facilities during the same ten-year period. These conditions simulated exposure routes that cattle in North America might encounter if they are raised or grazed in areas where free-ranging or captive deer and elk are infected with CWD. Beginning in July 2007 all exposed and three untreated control cattle were killed, and select tissues were collected at necropsy. Samples from each animal were analyzed for the diagnostic hallmarks of TSEs by immunohistochemistry and Western blot. DNA sequences were determined for the cellular prion protein gene in each animal. No proteinase-K resistant prion protein or anti-PrP immunoreactive IHC signals were detected in any tissues of exposed or control animals. None of these results, taken individually or together, support a diagnosis of TSE in cattle inoculated orally with a high dose of infectious CWD material or continually exposed by cohabitation with infected deer or elk, or transmission from contaminated premises despite an incubation period of up to 10 or 11 years.

Detection of protease-resistant cervid prion protein in water from a CWD-endemic area

T.A. Nichols,1,2 Bruce Pulford,1 A. Christy Wyckoff,1,2 Crystal Meyerett,1 Brady Michel,1 Kevin Gertig,3 Edward A. Hoover,1 Jean E. Jewell,4 Glenn C. Telling5 and Mark D. Zabel1,*

1Department of Microbiology, Immunology and Pathology; College of Veterinary Medicine and Biomedical Sciences; Colorado State University; Fort Collins, CO USA; 2National Wildlife Research Center; Wildlife Services; United States Department of Agriculture; Fort Collins, CO USA; 3Fort Collins Utilities; Fort Collins; CO USA; 4Department of Veterinary Sciences; Wyoming State Veterinary Laboratory; University of Wyoming; Laramie, WY USA; 5Department of Microbiology, Immunology, Molecular Genetics and Neurology; Sanders Brown Center on Aging; University of Kentucky; Lexington, KY USA

Key words: prions, chronic wasting disease, water, environment, serial protein misfolding cyclic amplification Abbreviations: CWD, chronic wasting disease; sPMCA, serial protein misfolding cyclic amplification; PrPC, cellular prion protein; PrPSc, disease-related, misfolded murine PrP; PrPCWD, disease-related, misfolded cervid PrP; PrPRES, protease-resistant PrP; FCWTF, Fort Collins water treatment facility

Chronic wasting disease (CWD) is the only known transmissible spongiform encephalopathy affecting free-ranging wildlife. Although the exact mode of natural transmission remains unknown, substantial evidence suggests that prions can persist in the environment, implicating components thereof as potential prion reservoirs and transmission vehicles.1-4 CWD-positive animals may contribute to environmental prion load via decomposing carcasses and biological materials including saliva, blood, urine and feces.5-7 Sensitivity limitations of conventional assays hamper evaluation of environmental prion loads in soil and water. Here we show the ability of serial protein misfolding cyclic amplification (sPMCA) to amplify a 1.3 x 10-7 dilution of CWD-infected brain homogenate spiked into water samples, equivalent to approximately 5 x 107 protease resistant cervid prion protein (PrPCWD) monomers. We also detected PrPCWD in one of two environmental water samples from a CWD endemic area collected at a time of increased water runoff from melting winter snow pack, as well as in water samples obtained concurrently from the flocculation stage of water processing by the municipal water treatment facility. Bioassays indicated that the PrPCWD detected was below infectious levels. These data demonstrate detection of very low levels of PrPCWD in the environment by sPMCA and suggest persistence and accumulation of prions in the environment that may promote CWD transmission.


The data presented here demonstrate that sPMCA can detect low levels of PrPCWD in the environment, corroborate previous biological and experimental data suggesting long term persistence of prions in the environment2,3 and imply that PrPCWD accumulation over time may contribute to transmission of CWD in areas where it has been endemic for decades. This work demonstrates the utility of sPMCA to evaluate other environmental water sources for PrPCWD, including smaller bodies of water such as vernal pools and wallows, where large numbers of cervids congregate and into which prions from infected animals may be shed and concentrated to infectious levels.

Monday, August 24, 2009 Third International CWD Symposium July 22-24, 2009 - Park City, Utah ABSTRACTS

Thursday, October 15, 2009

Transmissibility studies of vacuolar changes in the rostral colliculus of pigs


2005 DEFRA Department for Environment, Food & Rural Affairs

Area 307, London, SW1P 4PQ Telephone: 0207 904 6000 Direct line: 0207 904 6287 E-mail:


Mr T S Singeltary P.O. Box 42 Bacliff Texas USA 77518

21 November 2001

Dear Mr Singeltary


Thank you for e-mail regarding the hounds survey. I am sorry for the long delay in responding.

As you note, the hound survey remains unpublished. However the Spongiform Encephalopathy Advisory Committee (SEAC), the UK Government’s independent Advisory Committee on all aspects related to BSE-like disease, gave the hound study detailed consideration at their meeting in January 1994. As a summary of this meeting published in the BSE inquiry noted, the Committee were clearly concerned about the work that had been carried out, concluding that there had clearly been problems with it, particularly the control on the histology, and that it was more or less inconclusive. However was agreed that there should be a re-evaluation of the pathological material in the study.

Later, at their meeting in June 95, The Committee re-evaluated the hound study to see if any useful results could be gained from it. The Chairman concluded that there were varying opinions within the Committee on further work. It did not suggest any further transmission studies and thought that the lack of clinical data was a major weakness.

Overall, it is clear that SEAC had major concerns about the survey as conducted. As a result it is likely that the authors felt that it would not stand up to r~eer review and hence it was never published. As noted above, and in the detailed minutes of the SEAC meeting in June 95, SEAC considered whether additional work should be performed to examine dogs for evidence of TSE infection. Although the Committee had mixed views about the merits of conducting further work, the Chairman noted that when the Southwood Committee made their recommendation to complete an assessment of possible spongiform disease in dogs, no TSEs had been identified in other species and hence dogs were perceived as a high risk population and worthy of study. However subsequent to the original recommendation, made in 1990, a number of other species had been identified with TSE ( e.g. cats) so a study in hounds was less

critical. For more details see-

As this study remains unpublished, my understanding is that the ownership of the data essentially remains with the original researchers. Thus unfortunately, I am unable to help with your request to supply information on the hound survey directly. My only suggestion is that you contact one of the researchers originally involved in the project, such as Gerald Wells. He can be contacted at the following address.

Dr Gerald Wells, Veterinary Laboratories Agency, New Haw, Addlestone, Surrey, KT 15 3NB, UK

You may also wish to be aware that since November 1994 all suspected cases of spongiform encephalopathy in animals and poultry were made notifiable. Hence since that date there has been a requirement for vets to report any suspect SE in dogs for further investigation. To date there has never been positive identification of a TSE in a dog.

I hope this is helpful

Yours sincerely 4





b) Fibrillar material closely similar to SAF, found in BSE/Scrapie, was observed in 19 (4.3%) cases, all of which were hounds > 7 years of age. 14/19 of these suspected SAF results correlated with cases in the unresolveable histopathological category.


The following proposals address the hypothesis that the hound survey observations represent a PrP related or scrapie-like disease of dogs in which the pathological response, and possible the spread of infectivity, is neuroanatomically localized. By inference this could also mean that the disorder is clinically silent and non-progressive.

37.Putative TSE in hounds - work started 1990 -(see para 41)

Robert Higgins, a Veterinary Investigation Officer at Thirsk, had been working on a hound survey in 1990. Gerald Wells and I myself received histological sections from this survey along with the accompanying letter (YB90/11.28/1.1) dated November 1990. This letter details spongiform changes found in brains from hunt hounds failing to keep up with the rest of the pack, along with the results of SAF extractions from fresh brain material from these same animals. SAFs were not found in brains unless spongiform changes were also present. The spongiform changes were not pathognomonic (ie. conclusive proof) for prion disease, as they were atypical, being largely present in white matter rather than grey matter in the brain and spinal cord. However, Tony Scott, then head of electron microscopy work on TSEs, had no doubt that these SAFs were genuine and that these hounds therefore must have had a scrapie-like disease. I reviewed all the sections myself (original notes appended) and although the pathology was not typical, I could not exclude the possibility that this was a scrapie-like disorder, as white matter vacuolation is seen in TSEs and Wallerian degeneration was also present in the white matter of the hounds, another feature of scrapie.

38.I reviewed the literature on hound neuropathology, and discovered that micrographs and descriptive neuropathology from papers on 'hound ataxia' mirrored those in material from Robert Higgins' hound survey. Dr Tony Palmer (Cambridge) had done much of this work, and I obtained original sections from hound ataxia cases from him. This enabled me provisionally to conclude that Robert Higgins had in all probability detected hound ataxia, but also that hound ataxia itself was possibly a TSE. Gerald Wells confirmed in 'blind' examination of single restricted microscopic fields that there was no distinction between the white matter vacuolation present in BSE and scrapie cases, and that occurring in hound ataxia and the hound survey cases.

39.Hound ataxia had reportedly been occurring since the 1930's, and a known risk factor for its development was the feeding to hounds of downer cows, and particularly bovine offal. Circumstantial evidence suggests that bovine offal may also be causal in FSE, and TME in mink. Despite the inconclusive nature of the neuropathology, it was clearly evident that this putative canine spongiform encephalopathy merited further investigation.

40.The inconclusive results in hounds were never confirmed, nor was the link with hound ataxia pursued. I telephoned Robert Higgins six years after he first sent the slides to CVL. I was informed that despite his submitting a yearly report to the CVO including the suggestion that the hound work be continued, no further work had been done since 1991. This was surprising, to say the very least.

41.The hound work could have provided valuable evidence that a scrapie-like agent may have been present in cattle offal long before the BSE epidemic was recognised. The MAFF hound survey remains unpublished.

Histopathological support to various other published MAFF experiments

42.These included neuropathological examination of material from experiments studying the attempted transmission of BSE to chickens and pigs (CVL 1991) and to mice (RVC 1994).

nothing to offer scientifically;

maddogs and Englishman

kind regards, terry

###########bse-l ############

Date: Fri, 18 Oct 2002 23:12:22 +0100
From: Steve Dealler
Reply-To: Bovine Spongiform Encephalopathy Organization: Netscape Online member T
o: BSE-L@ References: <mhtml:%7B33B38F65-8D2E-434D-8F9B-8BDCD77D3066%7Dmid://00000164/!>

Dear Terry,

An excellent piece of review as this literature is desparately difficult to get back from Government sites.

What happened with the deer was that an association between deer meat eating and sporadic CJD was found in about 1993. The evidence was not great but did not disappear after several years of asking CJD cases what they had eaten. I think that the work into deer disease largely stopped because it was not helpful to the UK industry...and no specific cases were reported. Well, if you dont look adequately like they are in USA currenly then you wont find any!

Steve Dealler ===============

Incubation periods for BSE are proportional to the life expectancy of the animal affected. The disease's incubation period is 18% of a cow's life expectancy and would be expected to about double when crossing to another species [---] that is, to 36% of 70 years in humans.

Steve Dealler, consultant in medical microbiology. Burnley General Hospital, Burnley BB10 2PQ mhtml:%7B33B38F65-8D2E-434D-8F9B-8BDCD77D3066%7Dmid://00000164/!


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Surveillance for Prion diseases in the United States

Robert Holman, Ermias Belay, Krista Christensen, Ryan Maddox, Arialdi Minino, Arianne Folkema, Dana Haberling, Teresa Hammett, Kenneth Kochanek, Lawrence Schonberger CDC, USA

Background: Prion diseases are a family of rare progressive neurodegenerative disorders that affect humans and animals. The most common form of human prion disease, Creutzfeldt- Jakob disease (CJD), is believed to occur in many countries of the world. Variant CJD (vCJD), a recently emerged human prion disease, has been causally associated with bovine spongiform encephalopathy.

Objectives: To describe the occurrence of CJD and vCJD in the United States.

Methods: Analysis of prion disease deaths on death certificates of US residents, 1979-2006, and vCJD deaths identified through other surveillance mechanisms, 1996-2008. Since CJD is invariably fatal and illness duration is usually less than one year, the CJD incidence is estimated as the death rate.

Results: During 1979 through 2006, 6911 deaths with CJD listed as a cause were reported in the United States, an annual average of approximately 247 deaths (range 172-304 deaths). The average annual age-adjusted incidence for CJD was 0.97 per million persons (95% CI=0.95-0.99). Most (61.8%) of these cases occurred among persons 65 years of age for an average annual incidence in this age-group of 4.8 per million persons. Most cases were among whites (94.6%); the age-adjusted incidence for whites was >2.5 times higher than that for blacks (1.04 and 0.40, respectively). Three patients who died since 2004 were reported with vCJD; epidemiological evidence indicated that their infection was acquired outside of the United States.

Discussion: National surveillance continues to show an annual CJD incidence rate of about 1 case per million persons and marked differences in CJD rates by age and race in the United States. Ongoing surveillance remains important for monitoring the stability of the CJD incidence rates, and detecting occurrences of vCJD and possibly other novel prion diseases in the United States.


Neuropathology-confirmed CJD decedents less than 55 years of age, United States, 1994-2006

Ryan Maddox1, Robert Holman1, Pierluigi Gambetti2, Janis Blevins2, Sally Berri2, Arialdi Minino1, Krista Christensen1, James Sejvar1, Lawrence Schonberger1, Ermias Belay1 1Centers for Disease Control and Prevention, USA; 2National Prion Disease Pathology Surveillance Center, USA

Background: Approximately 10% of US Creutzfeldt-Jakob disease (CJD) decedents are reported to be <55 href="">

IN my opinion, all human TSE, OF ALL AGE GROUPS, must be reported in every State and Nation. THEY MUST BE REPORABLE if not for the following reason alone. IATROGENIC CREUTZFELDT JAKOB DISEASE knows no age group. The 'pass it forward' and or 'friendly fired' mode of transmission with TSE should be enough alone to manadory all human TSE reportable in every State, of any age. ...TSS

Tuesday, August 11, 2009 Characteristics of Established and Proposed Sporadic Creutzfeldt-Jakob Disease Variants

Brian S. Appleby, MD; Kristin K. Appleby, MD; Barbara J. Crain, MD, PhD; Chiadi U. Onyike, MD, MHS; Mitchell T. Wallin, MD, MPH; Peter V. Rabins, MD, MPH

Background: The classic Creutzfeldt-Jakob disease (CJD), Heidenhain, and Oppenheimer-Brownell variants are sporadic CJD (sCJD) phenotypes frequently described in the literature, but many cases present with neuropsychiatric symptoms, suggesting that there may be additional sCJD phenotypes.

Objective: To characterize clinical, diagnostic, and molecular features of 5 sCJD variants.

Design: Retrospective analysis.

Setting: The Johns Hopkins and Veterans Administration health care systems.

Participants: Eighty-eight patients with definite or probable sCJD.

Main Outcome Measures: Differences in age at onset, illness progression, diagnostic test results, and molecular subtype.

Results: The age at onset differed among sCJD variants (P=.03); the affective variant had the youngest mean age at onset (59.7 years). Survival time (P.001) and the time to clinical presentation (P=.003) differed among groups. Patients with the classic CJD phenotype had the shortest median survival time from symptom onset (66 days) and those who met criteria for the affective sCJD variant had the longest (421 days) and presented to clinicians significantly later (median time from onset to presentation, 92 days; P=.004). Cerebrospinal fluid analyses were positive for 14-3-3 protein in all of the affective variants, regardless of illness duration. Periodic sharp-wave complexes were not detected on any of the electroencephalography tracings in the Oppenheimer-Brownell group; basal ganglia hyperintensity was not detected on brain magnetic resonance imaging in this group either. All of the Heidenhain variants were of the methionine/ methionine type 1 molecular subtype.

Conclusions: The classic CJD phenotype and the Heidenhain, Oppenheimer-Brownell, cognitive, and affective sCJD variants differ by age at disease onset, survival time, and diagnostic test results. Characteristics of these 5 phenotypes are provided to facilitate further clinicopathologic investigation that may lead to more reliable and timely diagnoses of sCJD.

Arch Neurol. 2009;66(2):208-215

Monitoring the occurrence of emerging forms of Creutzfeldt-Jakob disease in the United States 2003 revisited 2009

August 10, 2009


I would like to submit a review of past CJD surveillance in the USA, and the urgent need to make all human TSE in the USA a reportable disease, in every state, of every age group, and to make this mandatory immediately without further delay. The ramifications of not doing so will only allow this agent to spread further in the medical, dental, surgical arena’s. North America seems to have the most species with documented Transmissible Spongiform Encephalopathy's, most all of which have been rendered and fed back to food producing animals and to humans for years. If you look at the statistics, sporadic CJD seems to be rising in the USA, and has been, with atypical cases of the sCJD. I find deeply disturbing in the year of 2009, that Human Transmissible Spongiform Encephalopathy of any strain and or phenotype, of all age groups, and I stress all age groups, because human TSE's do not know age, and they do not know borders. someone 56 years old, that has a human TSE, that has surgery, can pass this TSE agent on i.e. friendly fire, and or passing it forward, and there have been documented nvCJD in a 74 year old. Remembering also that only sporadic CJD has been documented to transmit via iatrogenic routes, until recently with the 4 cases of blood related transmission, of which the origin is thought to be nvCJD donors. However most Iatrogenic CJD cases are nothing more than sporadic CJD, until the source is proven, then it becomes Iatrogenic. An oxymoron of sorts, because all sporadic CJD is, are multiple forms, or strains, or phenotypes of Creutzfeldt Jakob Disease, that the route and source and species have not been confirmed and or documented. When will the myth of the UKBSEnvCJD only theory be put to bed for good. This theory in my opinion, and the following there from, as the GOLD STANDARD, has done nothing more than help spread this agent around the globe. Politics and money have caused the terrible consequences to date, and the fact that TSEs are a slow incubating death, but a death that is 100% certain for those that are exposed and live long enough to go clinical. once clinical, there is no recourse, to date. But, while sub-clinical, how many can one exposed human infect? Can humans exposed to CWD and scrapie strains pass it forward as some form of sporadic CJD in the surgical and medical arenas? why must we wait decades and decades to prove this point, only to expose millions needlessly, only for the sake of the industries involved? would it not have been prudent from the beginning to just include all TSE's, and rule them out from there with transmission studies and change policies there from, as opposed to doing just the opposite? The science of TSE's have been nothing more than a political circus since the beginning, and for anyone to still believe in this one strain, one group of bovines, in one geographical location, with only one age group of human TSE i.e. nvCJD myth, for anyone to believe this today only enhances to spreading of these human and animal TSE's. This is exactly why we have been in this quagmire.

The ones that believe that there is a spontaneous CJD in 85%+ of all cases of human TSE, and the ones that do not believe that cattle can have this same phenomenon, are two of the same, the industry, and so goes the political science aspect of this tobacco and or asbestos scenario i.e. follow the money. I could go into all angles of this man made nightmare, the real facts and science, for instance, the continuing rendering technology and slow cooking with low temps that brewed this stew up, and the fact that THE USA HAD THIS TECHNOLOGY FIRST AND SHIPPED IT TO THE U.K. SOME 5 YEARS BEFORE THE U.S. STARTED USING THE SAME TECHNOLOGY, to save on fuel cost. This is what supposedly amplified the TSE agent via sheep scrapie, and spread via feed in the U.K. bovine, and other countries exporting the tainted product. BUT most everyone ignores this fact, and the fact that the U.S. has been recycling more TSE, from more species with TSEs, than any other country documented, but yet, it's all spontaneous, and the rise in sporadic CJD in the U.S. is a happenstance of bad luck ??? I respectfully disagree. To top that all off, the infamous BSE-FIREWALL that the USDA always brags about was nothing more than ink on paper, and I can prove this. YOU can ignore it, but this is FACT (see source, as late as 2007, in one recall alone, some 10,000,000 MILLION POUNDS OF BANNED MAD COW FEED WENT OUT INTO COMMERCE TO BE FED OUT, and most was never recovered. This was banned blood laced, meat and bone meal. 2006 was a banner year for banned mad cow protein going into commerce in the U.S. (see source of FDA feed ban warning letter below). I stress that the August 4, 1997 USA mad cow feed ban and this infamous BSE firewall, was nothing more than ink on paper, it was never enforceable.

I propose that the current diagnostic criteria for human TSEs only enhances and helps the spreading of human TSE from the continued belief of the UKBSEnvCJD only theory in 2009. With all the science to date refuting it, to continue to validate this old myth, will only spread this TSE agent through a multitude of potential routes and sources i.e. consumption, medical i.e., surgical, blood, dental, endoscopy, optical, nutritional supplements, cosmetics etc. I propose as with Aguzzi, Asante, Collinge, Caughey, Deslys, Dormont, Gibbs, Gajdusek, Ironside, Manuelidis, Marsh, et al and many more, that the world of TSE Transmissible Spongiform Encephalopathy is far from an exact science, but there is enough proven science to date that this myth should be put to rest once and for all, and that we move forward with a new classification for human and animal TSE that would properly identify the infected species, the source species, and then the route. This would further have to be broken down to strain of species and then the route of transmission would further have to be broken down. Accumulation and Transmission are key to the threshold from sub- clinical to clinical disease, and key to all this, is to stop the amplification and transmission of this agent, the spreading of, no matter what strain. In my opinion, to continue with this myth that the U.K. strain of BSE one strain TSE in cows, and the nv/v CJD one strain TSE humans, and the one geographical location source i.e. U.K., and that all the rest of human TSE are just one single strain i.e. sporadic CJD, a happenstance of bad luck that just happens due to a twisted protein that just twisted the wrong way, IN 85%+ OF ALL HUMAN TSEs, when to date there are 6 different phenotypes of sCJD, and growing per Gambetti et al, and that no other animal TSE transmits to humans ??? With all due respect to all Scientist that believe this, I beg to differ. To continue with this masquerade will only continue to spread, expose, and kill, who knows how many more in the years and decades to come. ONE was enough for me, My Mom, hvCJD i.e. Heidenhain Variant CJD, DOD 12/14/97 confirmed, which is nothing more than another mans name added to CJD, like CJD itself, Jakob and Creutzfeldt, or Gerstmann-Straussler-Scheinker syndrome, just another CJD or human TSE, named after another human. WE are only kidding ourselves with the current diagnostic criteria for human and animal TSE, especially differentiating between the nvCJD vs the sporadic CJD strains and then the GSS strains and also the FFI fatal familial insomnia strains or the ones that mimics one or the other of those TSE? Tissue infectivity and strain typing of the many variants of the human and animal TSEs are paramount in all variants of all TSE. There must be a proper classification that will differentiate between all these human TSE in order to do this. With the CDI and other more sensitive testing coming about, I only hope that my proposal will some day be taken seriously. ...

please see history, and the ever evolving TSE science to date ;

Saturday, June 13, 2009

Monitoring the occurrence of emerging forms of Creutzfeldt-Jakob disease in the United States 2003 revisited 2009


MARCH 26, 2003

Send Post-Publication Peer Review to journal:

Re: RE-Monitoring the occurrence of emerging forms of Creutzfeldt-Jakob

disease in the United States

Email Terry S. Singeltary:


I lost my mother to hvCJD (Heidenhain Variant CJD). I would like to comment on the CDC's attempts to monitor the occurrence of emerging forms of CJD. Asante, Collinge et al [1] have reported that BSE transmission to the 129-methionine genotype can lead to an alternate phenotype that is indistinguishable from type 2 PrPSc, the commonest sporadic CJD. However, CJD and all human TSEs are not reportable nationally. CJD and all human TSEs must be made reportable in every state and internationally. I hope that the CDC does not continue to expect us to still believe that the 85%+ of all CJD cases which are sporadic are all spontaneous, without route/source. We have many TSEs in the USA in both animal and man. CWD in deer/elk is spreading rapidly and CWD does transmit to mink, ferret, cattle, and squirrel monkey by intracerebral inoculation. With the known incubation periods in other TSEs, oral transmission studies of CWD may take much longer. Every victim/family of CJD/TSEs should be asked about route and source of this agent. To prolong this will only spread the agent and needlessly expose others. In light of the findings of Asante and Collinge et al, there should be drastic measures to safeguard the medical and surgical arena from sporadic CJDs and all human TSEs. I only ponder how many sporadic CJDs in the USA are type 2 PrPSc?


Volume 3, Number 8 01 August 2003


Tracking spongiform encephalopathies in North America

Xavier Bosch

My name is Terry S Singeltary Sr, and I live in Bacliff, Texas. I lost my mom to hvCJD (Heidenhain variant CJD) and have been searching for answers ever since. What I have found is that we have not been told the truth. CWD in deer and elk is a small portion of a much bigger problem.

49-year-old Singeltary is one of a number of people who have remained largely unsatisfied after being told that a close relative died from a rapidly progressive dementia compatible with spontaneous Creutzfeldt-Jakob disease (CJD). So he decided to gather hundreds of documents on transmissible spongiform encephalopathies (TSE) and realised that if Britons could get variant CJD from bovine spongiform encephalopathy (BSE), Americans might get a similar disorder from chronic wasting disease (CWD)the relative of mad cow disease seen among deer and elk in the USA. Although his feverish search did not lead him to the smoking gun linking CWD to a similar disease in North American people, it did uncover a largely disappointing situation.

Singeltary was greatly demoralised at the few attempts to monitor the occurrence of CJD and CWD in the USA. Only a few states have made CJD reportable. Human and animal TSEs should be reportable nationwide and internationally, he complained in a letter to the Journal of the American Medical Association (JAMA 2003; 285: 733). I hope that the CDC does not continue to expect us to still believe that the 85% plus of all CJD cases which are sporadic are all spontaneous, without route or source.

Until recently, CWD was thought to be confined to the wild in a small region in Colorado. But since early 2002, it has been reported in other areas, including Wisconsin, South Dakota, and the Canadian province of Saskatchewan. Indeed, the occurrence of CWD in states that were not endemic previously increased concern about a widespread outbreak and possible transmission to people and cattle.

To date, experimental studies have proven that the CWD agent can be transmitted to cattle by intracerebral inoculation and that it can cross the mucous membranes of the digestive tract to initiate infection in lymphoid tissue before invasion of the central nervous system. Yet the plausibility of CWD spreading to people has remained elusive.

Part of the problem seems to stem from the US surveillance system. CJD is only reported in those areas known to be endemic foci of CWD. Moreover, US authorities have been criticised for not having performed enough prionic tests in farm deer and elk.

Although in November last year the US Food and Drug Administration issued a directive to state public-health and agriculture officials prohibiting material from CWD-positive animals from being used as an ingredient in feed for any animal species, epidemiological control and research in the USA has been quite different from the situation in the

UK and Europe regarding BSE.

Getting data on TSEs in the USA from the government is like pulling teeth, Singeltary argues. You get it when they want you to have it and only what they want you to have.Norman Foster, director of the Cognitive Disorders Clinic at the University of Michigan (Ann Arbor, MI, USA), says that current surveillance of prion disease in people in the USA is inadequate to detect whether CWD is occurring in human beings; adding that, the cases that we know about are reassuring, because they do not suggest the appearance of a new variant of CJD in the USA or atypical features in patients that might be exposed to CWD. However, until we establish a system that identifies and analyses a high proportion of suspected prion disease cases we will not know for sure. The USA should develop a system modelled on that established in the UK, he points out.

Ali Samii, a neurologist at Seattle VA Medical Center who recently reported the cases of three hunterstwo of whom were friendswho died from pathologically confirmed CJD, says that at present there are insufficient data to claim transmission of CWD into humans; adding that [only] by asking [the questions of venison consumption and deer/elk hunting] in every case can we collect suspect cases and look into the plausibility of transmission further. Samii argues that by making both doctors and hunters more aware of the possibility of prions spreading through eating venison, doctors treating hunters with dementia can consider a possible prion disease, and doctors treating CJD patients will know to ask whether they ate venison. CDC spokesman Ermias Belay says that the CDC will not be investigating the [Samii] cases because there is no evidence that the men ate CWD-infected meat. He notes that although the likelihood of CWD jumping the species barrier to infect humans cannot be ruled out 100% and that [we] cannot be 100% sure that CWD does not exist in humans & the data seeking evidence of CWD transmission to humans have been very limited.

he complained in a letter to the Journal of the American Medical Association (JAMA 2003; 285: 733). 

I hope that the CDC does not continue to expect us to still believe that the 85% plus of all CJD cases which are sporadic are all spontaneous, without route or source.<<< href="mhtml:%7B33B38F65-8D2E-434D-8F9B-8BDCD77D3066%7Dmid://00000164/!x-usc:">

2 January 2000

British Medical Journal

U.S. Scientist should be concerned with a CJD epidemic in the U.S., as well

15 November 1999

British Medical Journal

vCJD in the USA * BSE in U.S.


BY Philip Yam

Yam Philip Yam News Editor Scientific American


Answering critics like Terry Singeltary, who feels that the U.S. undercounts CJD, Schonberger conceded that the current surveillance system has errors but stated that most of the errors will be confined to the older population. ...

Sunday, August 10, 2008

A New Prionopathy OR more of the same old BSe and sporadic CJD


The statistical incidence of CJD cases in the United States has been revised to reflect that there is one case per 9000 in adults age 55 and older. Eighty-five percent of the cases are sporadic, meaning there is no known cause at present.

Friday, November 30, 2007


Sunday, September 6, 2009





Office of Inspector General Semiannual Report to Congress FY 2007 - 2nd Half

Two Texas Companies Sentenced and Fined for Misbranding Meat Products In April 2007, two closely held and related Texas companies pled guilty in Federal court and were sentenced to 12 months of probation and ordered to pay $10,250 in fines for misbranding meat products. One of the companies sold adulterated meat products to a retail store in New Mexico. Additionally, portions of the invoices failed to properly and consistently identify the meat products as being from cattle more than 30 months old at time of slaughter. This information is required to be disclosed because of bovine spongiform encephalopathy (BSE, or "mad cow disease") concerns. No adulterated meat reached consumers.

Saturday, August 29, 2009

FOIA REQUEST FEED RECALL 2009 Product may have contained prohibited materials Bulk Whole Barley, Recall # V-256-2009

Friday, September 4, 2009

FOIA REQUEST ON FEED RECALL PRODUCT 429,128 lbs. feed for ruminant animals may have been contaminated with prohibited material Recall # V-258-2009

THIS recall is not confusing ;


Date: March 21, 2007 at 2:27 pm PST




Bulk cattle feed made with recalled Darling's 85% Blood Meal, Flash Dried, Recall # V-024-2007


Cattle feed delivered between 01/12/2007 and 01/26/2007


Pfeiffer, Arno, Inc, Greenbush, WI. by conversation on February 5, 2007.

Firm initiated recall is ongoing.


Blood meal used to make cattle feed was recalled because it was cross- contaminated with prohibited bovine meat and bone meal that had been manufactured on common equipment and labeling did not bear cautionary BSE statement.


42,090 lbs.







The firm does not utilize a code - only shipping documentation with commodity and weights identified.


Rangen, Inc, Buhl, ID, by letters on February 13 and 14, 2007. Firm initiated recall is complete.


Products manufactured from bulk feed containing blood meal that was cross contaminated with prohibited meat and bone meal and the labeling did not bear cautionary BSE statement.


9,997,976 lbs.


ID and NV



Thursday, March 19, 2009


Sunday, October 18, 2009

Wisconsin Firm Recalls Beef Tongues That Contain Prohibited Materials SRM WASHINGTON, October 17, 2009

Thursday, October 15, 2009

Nebraska Firm Recalls Beef Tongues That Contain Prohibited Materials SRM WASHINGTON, Oct 15, 2009

Tuesday, July 14, 2009

U.S. Emergency Bovine Spongiform Encephalopathy Response Plan Summary and BSE Red Book Date: February 14, 2000 at 8:56 am PST

WHERE did we go wrong $$$

Sunday, December 28, 2008

MAD COW DISEASE USA DECEMBER 28, 2008 an 8 year review of a failed and flawed policy

Wednesday, August 20, 2008

Bovine Spongiform Encephalopathy Mad Cow Disease typical and atypical strains, was there a cover-up ? August 20, 2008

Monday, May 11, 2009

Rare BSE mutation raises concerns over risks to public health

Tuesday, July 14, 2009

U.S. Emergency Bovine Spongiform Encephalopathy Response Plan Summary and BSE Red Book Date: February 14, 2000 at 8:56 am PST

WHERE did we go wrong $$$

Sunday, June 07, 2009


Sunday, May 10, 2009

Identification and characterization of bovine spongiform encephalopathy cases diagnosed and NOT diagnosed in the United States

Docket APHIS-2006-0026 Docket Title Bovine Spongiform Encephalopathy; Animal Identification and Importation of Commodities Docket Type Rulemaking Document APHIS-2006-0026-0001 Document Title Bovine Spongiform Encephalopathy; Minimal-Risk Regions, Identification of Ruminants and Processing and Importation of Commodities Public Submission APHIS-2006-0026-0012 Public Submission Title Comment from Terry S Singletary

Docket APHIS-2006-0041 Docket Title Bovine Spongiform Encephalopathy; Minimal-Risk Regions; Importation of Live Bovines and Products Derived from Bovines Commodities Docket Type Rulemaking Document APHIS-2006-0041-0001 Document Title Bovine Spongiform Encephalopathy; Minimal-Risk Regions; Importation of Live Bovines and Products Derived From Bovines Public Submission APHIS-2006-0041-0028 Public Submission Title Comment from Terry S Singletary


THE USA is in a most unique situation, one of unknown circumstances with human and animal TSE. THE USA has the most documented TSE in different species to date, with substrains growing in those species (BSE/BASE in cattle and CWD in deer and elk, there is evidence here with different strains), and we know that sheep scrapie has over 20 strains of the typical scrapie with atypical scrapie documented and also BSE is very likely to have passed to sheep. all of which have been rendered and fed back to animals for human and animal consumption, a frightening scenario. WE do not know the outcome, and to play with human life around the globe with the very likely TSE tainted products from the USA, in my opinion is like playing Russian roulette, of long duration, with potential long and enduring consequences, of which once done, cannot be undone. These are the facts as I have come to know through daily and extensive research of TSE over 9 years, since 12/14/97. I do not pretend to have all the answers, but i do know to continue to believe in the ukbsenvcjd only theory of transmission to humans of only this one strain from only this one TSE from only this one part of the globe, will only lead to further failures, and needless exposure to humans from all strains of TSE, and possibly many more needless deaths from TSE via a multitude of proven routes and sources via many studies with primates and rodents and other species.

MY personal belief, since you ask, is that not only the Canadian border, but the USA border, and the Mexican border should be sealed up tighter than a drum for exporting there TSE tainted products, until a validated, 100% sensitive test is available, and all animals for human and animal consumption are tested. all we are doing is the exact same thing the UK did with there mad cow poisoning when they exported it all over the globe, all the while knowing what they were doing. this BSE MRR policy is nothing more than a legal tool to do just exactly what the UK did, thanks to the OIE and GW, it's legal now. and they executed Saddam for poisoning ???

go figure. ...

Docket APHIS-2006-0041 Docket Title Bovine Spongiform Encephalopathy; Minimal-Risk Regions; Importation of Live Bovines and Products Derived from Bovines Commodities Docket Type Rulemaking Document APHIS-2006-0041-0001 Document Title Bovine Spongiform Encephalopathy; Minimal-Risk Regions; Importation of Live Bovines and Products Derived From Bovines Public Submission APHIS-2006-0041-0028.1 Public Submission Title Attachment to Singletary comment

January 28, 2007

Greetings APHIS,

I would kindly like to submit the following to ;


Thursday, October 15, 2009

CVM Annual Report Fiscal Year 2008: October 1, 2007-September 30, 2008 (BSE)

Wednesday, August 19, 2009

CFIA Enhances Animal Disease Reporting

Thursday, October 15, 2009

SCRAPIE UPDATE CANADA 2009 (typical and atypical cases)


• Are some commoner types of neurodegenerative disease (including Alzheimer's disease and Parkinson's disease) also transmissible? Some recent scientific research has suggested this possibility

Alzheimer's and CJD

Terry S. Singeltary Sr.
P.O. Box 42
Bacliff, Texas USA 77518

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