98 | Veterinary Record | January 24, 2015
Scrapie: a particularly persistent pathogen
Resistant prions in the environment have been the sword of Damocles for scrapie control and eradication. Attempts to establish which physical and chemical agents could be applied to inactivate or moderate scrapie infectivity were initiated in the 1960s and 1970s,with the first study of this type focusing on the effect of heat treatment in reducing prion infectivity (Hunter and Millson 1964). Nowadays, most of the chemical procedures that aim to inactivate the prion protein are based on the method developed by Kimberlin and collaborators (1983). This procedure consists of treatment with 20,000 parts per million free chlorine solution, for a minimum of one hour, of all surfaces that need to be sterilised (in laboratories, lambing pens, slaughterhouses, and so on). Despite this, veterinarians and farmers may still ask a range of questions, such as ‘Is there an official procedure published somewhere?’ and ‘Is there an international organisation which recommends and defines the exact method of scrapie decontamination that must be applied?’
From a European perspective, it is difficult to find a treatment that could be applied, especially in relation to the disinfection of surfaces in lambing pens of affected flocks. A 999/2001 EU regulation on controlling spongiform encephalopathies (European Parliament and Council 2001) did not specify a particular decontamination measure to be used when an outbreak of scrapie is diagnosed. There is only a brief recommendation in Annex VII concerning the control and eradication of transmissible spongiform encephalopathies (TSE s).
Chapter B of the regulation explains the measures that must be applied if new caprine animals are to be introduced to a holding where a scrapie outbreak has previously been diagnosed. In that case, the statement indicates that caprine animals can be introduced ‘provided that a cleaning and disinfection of all animal housing on the premises has been carried out following destocking’.
Issues around cleaning and disinfection are common in prion prevention recommendations, but relevant authorities, veterinarians and farmers may have difficulties in finding the specific protocol which applies. The European Food and Safety Authority (EFSA ) published a detailed report about the efficacy of certain biocides, such as sodium hydroxide, sodium hypochlorite, guanidine and even a formulation of copper or iron metal ions in combination with hydrogen peroxide, against prions (EFSA 2009). The report was based on scientific evidence (Fichet and others 2004, Lemmer and others 2004, Gao and others 2006, Solassol and others 2006) but unfortunately the decontamination measures were not assessed under outbreak conditions.
The EFSA Panel on Biological Hazards recently published its conclusions on the scrapie situation in the EU after 10 years of monitoring and control of the disease in sheep and goats (EFSA 2014), and one of the most interesting findings was the Icelandic experience regarding the effect of disinfection in scrapie control. The Icelandic plan consisted of: culling scrapie-affected sheep or the whole flock in newly diagnosed outbreaks; deep cleaning and disinfection of stables, sheds, barns and equipment with high pressure washing followed by cleaning with 500 parts per million of hypochlorite; drying and treatment with 300 ppm of iodophor; and restocking was not permitted for at least two years. Even when all of these measures were implemented, scrapie recurred on several farms, indicating that the infectious agent survived for years in the environment, even as many as 16 years after restocking (Georgsson and others 2006).
In the rest of the countries considered in the EFSA (2014) report, recommendations for disinfection measures were not specifically defined at the government level. In the report, the only recommendation that is made for sheep is repopulation with sheep with scrapie-resistant genotypes. This reduces the risk of scrapie recurrence but it is difficult to know its effect on the infection.
Until the EFSA was established (in May 2003), scientific opinions about TSE s were provided by the Scientific Steering Committee (SSC) of the EC, whose advice regarding inactivation procedures focused on treating animal waste at high temperatures (150°C for three hours) and high pressure alkaline hydrolysis (SSC 2003). At the same time, the TSE Risk Management Subgroup of the Advisory Committee on Dangerous Pathogens (ACDP) in the UK published guidance on safe working and the prevention of TSE infection. Annex C of the ACDP report established that sodium hypochlorite was considered to be effective, but only if 20,000 ppm of available chlorine was present for at least one hour, which has practical limitations such as the release of chlorine gas, corrosion, incompatibility with formaldehyde, alcohols and acids, rapid inactivation of its active chemicals and the stability of dilutions (ACDP 2009).
In an international context, the World Organisation for Animal Health (OIE) does not recommend a specific disinfection protocol for prion agents in its Terrestrial Code or Manual. Chapter 4.13 of the Terrestrial Code, General recommendations on disinfection and disinsection (OIE 2014), focuses on foot-and-mouth disease virus, mycobacteria and Bacillus anthracis, but not on prion disinfection. Nevertheless, the last update published by the OIE on bovine spongiform encephalopathy (OIE 2012) indicates that few effective decontamination techniques are available to inactivate the agent on surfaces, and recommends the removal of all organic material and the use of sodium hydroxide, or a sodium hypochlorite solution containing 2 per cent available chlorine, for more than one hour at 20ºC.
The World Health Organization outlines guidelines for the control of TSE s, and also emphasises the importance of mechanically cleaning surfaces before disinfection with sodium hydroxide or sodium hypochlorite for one hour (WHO 1999).
Finally, the relevant agencies in both Canada and the USA suggest that the best treatments for surfaces potentially contaminated with prions are sodium hydroxide or sodium hypochlorite at 20,000 ppm. This is a 2 per cent solution, while most commercial household bleaches contain 5.25 per cent sodium hypochlorite. It is therefore recommended to dilute one part 5.25 per cent bleach with 1.5 parts water (CDC 2009, Canadian Food Inspection Agency 2013).
So what should we do about disinfection against prions? First, it is suggested that a single protocol be created by international authorities to homogenise inactivation procedures and enable their application in all scrapie-affected countries. Sodium hypochlorite with 20,000 ppm of available chlorine seems to be the procedure used in most countries, as noted in a paper summarised on p 99 of this issue of Veterinary Record (Hawkins and others 2015). But are we totally sure of its effectiveness as a preventive measure in a scrapie outbreak? Would an in-depth study of the recurrence of scrapie disease be needed?
What we can conclude is that, if we want to fight prion diseases, and specifically classical scrapie, we must focus on the accuracy of diagnosis, monitoring and surveillance; appropriate animal identification and control of movements; and, in the end, have homogeneous and suitable protocols to decontaminate and disinfect lambing barns, sheds and equipment available to veterinarians and farmers. Finally, further investigations into the resistance of prion proteins in the diversity of environmental surfaces are required.
98 | Veterinary Record | January 24, 2015
Persistence of ovine scrapie infectivity in a farm environment following cleaning and decontamination
Steve A. C. Hawkins, MIBiol, Pathology Department1, Hugh A. Simmons, BVSc MRCVS, MBA, MA Animal Services Unit1, Kevin C. Gough, BSc, PhD2 and Ben C. Maddison, BSc, PhD3 + Author Affiliations
1Animal and Plant Health Agency, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK 2School of Veterinary Medicine and Science, The University of Nottingham, Sutton Bonington, Loughborough, Leicestershire LE12 5RD, UK 3ADAS UK, School of Veterinary Medicine and Science, The University of Nottingham, Sutton Bonington, Loughborough, Leicestershire LE12 5RD, UK E-mail for correspondence: email@example.com Abstract Scrapie of sheep/goats and chronic wasting disease of deer/elk are contagious prion diseases where environmental reservoirs are directly implicated in the transmission of disease. In this study, the effectiveness of recommended scrapie farm decontamination regimens was evaluated by a sheep bioassay using buildings naturally contaminated with scrapie. Pens within a farm building were treated with either 20,000 parts per million free chorine solution for one hour or were treated with the same but were followed by painting and full re-galvanisation or replacement of metalwork within the pen. Scrapie susceptible lambs of the PRNP genotype VRQ/VRQ were reared within these pens and their scrapie status was monitored by recto-anal mucosa-associated lymphoid tissue. All animals became infected over an 18-month period, even in the pen that had been subject to the most stringent decontamination process. These data suggest that recommended current guidelines for the decontamination of farm buildings following outbreaks of scrapie do little to reduce the titre of infectious scrapie material and that environmental recontamination could also be an issue associated with these premises.
Thorough pressure washing of a pen had no effect on the amount of bioavailable scrapie infectivity (pen B). The routine removal of prions from surfaces within a laboratory setting is treatment for a minimum of one hour with 20,000 ppm free chlorine, a method originally based on the use of brain macerates from infected rodents to evaluate the effectiveness of decontamination (Kimberlin and others 1983). Further studies have also investigated the effectiveness of hypochlorite disinfection of metal surfaces to simulate the decontamination of surgical devices within a hospital setting. Such treatments with hypochlorite solution were able to reduce infectivity by 5.5 logs to lower than the sensitivity of the bioassay used (Lemmer and others 2004). Analogous treatment of the pen surfaces did not effectively remove the levels of scrapie infectivity over that of the control pens, indicating that this method of decontamination is not effective within a farm setting. This may be due to the high level of biological matrix that is present upon surfaces within the farm environment, which may reduce the amount of free chlorine available to inactivate any infectious prion. Remarkably 1/5 sheep introduced into pen D had also became scrapie positive within nine months, with all animals in this pen being RAMALT positive by 18 months of age. Pen D was no further away from the control pen (pen A) than any of the other pens within this barn. Localised hot spots of infectivity may be present within scrapie-contaminated environments, but it is unlikely that pen D area had an amount of scrapie contamination that was significantly different than the other areas within this building. Similarly, there were no differences in how the biosecurity of pen D was maintained, or how this pen was ventilated compared with the other pens. This observation, perhaps, indicates the slower kinetics of disease uptake within this pen and is consistent with a more thorough prion removal and recontamination. These observations may also account for the presence of inadvertent scrapie cases within other studies, where despite stringent biosecurity, control animals have become scrapie positive during challenge studies using barns that also housed scrapie-affected animals (Ryder and others 2009). The bioassay data indicate that the exposure of the sheep to a farm environment after decontamination efforts thought to be effective in removing scrapie is sufficient for the animals to become infected with scrapie. The main exposure routes within this scenario are likely to be via the oral route, during feeding and drinking, and respiratory and conjunctival routes. It has been demonstrated that scrapie infectivity can be efficiently transmitted via the nasal route in sheep (Hamir and others 2008), as is the case for CWD in both murine models and in white-tailed deer (Denkers and others 2010, 2013). Recently, it has also been demonstrated that CWD prions presented as dust when bound to the soil mineral montmorillonite can be infectious via the nasal route (Nichols and others 2013). When considering pens C and D, the actual source of the infectious agent in the pens is not known, it is possible that biologically relevant levels of prion survive on surfaces during the decontamination regimen (pen C). With the use of galvanising and painting (pen D) covering and sealing the surface of the pen, it is possible that scrapie material recontaminated the pens by the movement of infectious prions contained within dusts originating from other parts of the barn that were not decontaminated or from other areas of the farm.
Given that scrapie prions are widespread on the surfaces of affected farms (Maddison and others 2010a), irrespective of the source of the infectious prions in the pens, this study clearly highlights the difficulties that are faced with the effective removal of environmentally associated scrapie infectivity. This is likely to be paralleled in CWD which shows strong similarities to scrapie in terms of both the dissemination of prions into the environment and the facile mode of disease transmission. These data further contribute to the understanding that prion diseases can be highly transmissible between susceptible individuals not just by direct contact but through highly stable environmental reservoirs that are refractory to decontamination.
The presence of these environmentally associated prions in farm buildings make the control of these diseases a considerable challenge, especially in animal species such as goats where there is lack of genetic resistance to scrapie and, therefore, no scope to re-stock farms with animals that are resistant to scrapie.
Scrapie Sheep Goats Transmissible spongiform encephalopathies (TSE) Accepted October 12, 2014. Published Online First 31 October 2014
Monday, November 3, 2014
Persistence of ovine scrapie infectivity in a farm environment following cleaning and decontamination
Detection of Environmentally Associated PrPSc on a Farm with Endemic Scrapie
Ben C. Maddison,1 Claire A. Baker,1 Helen C. Rees,1 Linda A. Terry,2 Leigh Thorne,2 Susan J. Belworthy2 and Kevin C. Gough3 1ADAS-UK LTD; Department of Biology; University of Leicester; Leicester, UK; 2Veterinary Laboratories Agency; Surry, KT UK; 3Department of Veterinary Medicine and Science; University of Nottingham; Sutton Bonington, Loughborough UK
Key words: scrapie, evironmental persistence, sPMCA
Ovine scrapie shows considerable horizontal transmission, yet the routes of transmission and specifically the role of fomites in transmission remain poorly defined. Here we present biochemical data demonstrating that on a scrapie-affected sheep farm, scrapie prion contamination is widespread. It was anticipated at the outset that if prions contaminate the environment that they would be there at extremely low levels, as such the most sensitive method available for the detection of PrPSc, serial Protein Misfolding Cyclic Amplification (sPMCA), was used in this study. We investigated the distribution of environmental scrapie prions by applying ovine sPMCA to samples taken from a range of surfaces that were accessible to animals and could be collected by use of a wetted foam swab. Prion was amplified by sPMCA from a number of these environmental swab samples including those taken from metal, plastic and wooden surfaces, both in the indoor and outdoor environment. At the time of sampling there had been no sheep contact with these areas for at least 20 days prior to sampling indicating that prions persist for at least this duration in the environment. These data implicate inanimate objects as environmental reservoirs of prion infectivity which are likely to contribute to disease transmission.
PO-039: A comparison of scrapie and chronic wasting disease in white-tailed deer
Justin Greenlee, Jodi Smith, Eric Nicholson US Dept. Agriculture; Agricultural Research Service, National Animal Disease Center; Ames, IA USA
The results of this study suggest that there are many similarities in the manifestation of CWD and scrapie in WTD after IC inoculation including early and widespread presence of PrPSc in lymphoid tissues, clinical signs of depression and weight loss progressing to wasting, and an incubation time of 21-23 months. Moreover, western blots (WB) done on brain material from the obex region have a molecular profile similar to CWD and distinct from tissues of the cerebrum or the scrapie inoculum. However, results of microscopic and IHC examination indicate that there are differences between the lesions expected in CWD and those that occur in deer with scrapie: amyloid plaques were not noted in any sections of brain examined from these deer and the pattern of immunoreactivity by IHC was diffuse rather than plaque-like.
*** After a natural route of exposure, 100% of WTD were susceptible to scrapie.
Deer developed clinical signs of wasting and mental depression and were necropsied from 28 to 33 months PI. Tissues from these deer were positive for PrPSc by IHC and WB. Similar to IC inoculated deer, samples from these deer exhibited two different molecular profiles: samples from obex resembled CWD whereas those from cerebrum were similar to the original scrapie inoculum. On further examination by WB using a panel of antibodies, the tissues from deer with scrapie exhibit properties differing from tissues either from sheep with scrapie or WTD with CWD. Samples from WTD with CWD or sheep with scrapie are strongly immunoreactive when probed with mAb P4, however, samples from WTD with scrapie are only weakly immunoreactive. In contrast, when probed with mAb’s 6H4 or SAF 84, samples from sheep with scrapie and WTD with CWD are weakly immunoreactive and samples from WTD with scrapie are strongly positive. This work demonstrates that WTD are highly susceptible to sheep scrapie, but on first passage, scrapie in WTD is differentiable from CWD.
*** After a natural route of exposure, 100% of white-tailed deer were susceptible to scrapie.
*** We conclude that TSE infectivity is likely to survive burial for long time periods with minimal loss of infectivity and limited movement from the original burial site. However PMCA results have shown that there is the potential for rainwater to elute TSE related material from soil which could lead to the contamination of a wider area. These experiments reinforce the importance of risk assessment when disposing of TSE risk materials.
*** The results show that even highly diluted PrPSc can bind efficiently to polypropylene, stainless steel, glass, wood and stone and propagate the conversion of normal prion protein. For in vivo experiments, hamsters were ic injected with implants incubated in 1% 263K-infected brain homogenate. Hamsters, inoculated with 263K-contaminated implants of all groups, developed typical signs of prion disease, whereas control animals inoculated with non-contaminated materials did not.
PRION 2014 CONFERENCE
CHRONIC WASTING DISEASE CWD
A FEW FINDINGS ;
Conclusions. To our knowledge, this is the first established experimental model of CWD in TgSB3985. We found evidence for co-existence or divergence of two CWD strains adapted to Tga20 mice and their replication in TgSB3985 mice. Finally, we observed phenotypic differences between cervid-derived CWD and CWD/Tg20 strains upon propagation in TgSB3985 mice. Further studies are underway to characterize these strains.
We conclude that TSE infectivity is likely to survive burial for long time periods with minimal loss of infectivity and limited movement from the original burial site. However PMCA results have shown that there is the potential for rainwater to elute TSE related material from soil which could lead to the contamination of a wider area. These experiments reinforce the importance of risk assessment when disposing of TSE risk materials.
The results show that even highly diluted PrPSc can bind efficiently to polypropylene, stainless steel, glass, wood and stone and propagate the conversion of normal prion protein. For in vivo experiments, hamsters were ic injected with implants incubated in 1% 263K-infected brain homogenate. Hamsters, inoculated with 263K-contaminated implants of all groups, developed typical signs of prion disease, whereas control animals inoculated with non-contaminated materials did not.
Our data establish that meadow voles are permissive to CWD via peripheral exposure route, suggesting they could serve as an environmental reservoir for CWD. Additionally, our data are consistent with the hypothesis that at least two strains of CWD circulate in naturally-infected cervid populations and provide evidence that meadow voles are a useful tool for CWD strain typing.
Conclusion. CWD prions are shed in saliva and urine of infected deer as early as 3 months post infection and throughout the subsequent >1.5 year course of infection. In current work we are examining the relationship of prionemia to excretion and the impact of excreted prion binding to surfaces and particulates in the environment.
Conclusion. CWD prions (as inferred by prion seeding activity by RT-QuIC) are shed in urine of infected deer as early as 6 months post inoculation and throughout the subsequent disease course. Further studies are in progress refining the real-time urinary prion assay sensitivity and we are examining more closely the excretion time frame, magnitude, and sample variables in relationship to inoculation route and prionemia in naturally and experimentally CWD-infected cervids.
Conclusions. Our results suggested that the odds of infection for CWD is likely controlled by areas that congregate deer thus increasing direct transmission (deer-to-deer interactions) or indirect transmission (deer-to-environment) by sharing or depositing infectious prion proteins in these preferred habitats. Epidemiology of CWD in the eastern U.S. is likely controlled by separate factors than found in the Midwestern and endemic areas for CWD and can assist in performing more efficient surveillance efforts for the region.
Conclusions. During the pre-symptomatic stage of CWD infection and throughout the course of disease deer may be shedding multiple LD50 doses per day in their saliva. CWD prion shedding through saliva and excreta may account for the unprecedented spread of this prion disease in nature.
see full text and more ;
Monday, June 23, 2014
*** PRION 2014 CONFERENCE CHRONIC WASTING DISEASE CWD
*** Infectious agent of sheep scrapie may persist in the environment for at least 16 years***
Gudmundur Georgsson1, Sigurdur Sigurdarson2 and Paul Brown3
New studies on the heat resistance of hamster-adapted scrapie agent: Threshold survival after ashing at 600°C suggests an inorganic template of replication
Prion Infected Meat-and-Bone Meal Is Still Infectious after Biodiesel Production
Detection of protease-resistant cervid prion protein in water from a CWD-endemic area
A Quantitative Assessment of the Amount of Prion Diverted to Category 1 Materials and Wastewater During Processing
Rapid assessment of bovine spongiform encephalopathy prion inactivation by heat treatment in yellow grease produced in the industrial manufacturing process of meat and bone meals
Sunday, December 21, 2014
Mucosal immunization with an attenuated Salmonella vaccine partially protects white-tailed deer from chronic wasting disease
Friday, December 19, 2014
Pan-Provincial Vaccine Enterprise Inc. (PREVENT) Conducting a Chronic Wasting Disease (CWD) Vaccine Efficacy Trial in Elk
Friday, January 16, 2015
Indiana SENATE BILL No. 442 Miller Pete Hunting wildlife Removes exotic mammals from the animals that may be propagated or offered for hunting at a shooting preserve Makes it a Class C misdemeanor
CHRONIC WASTING DISEASE CWD TSE PRION, how much does it pay to find CWD $$$
CWD, spreading it around...
Tuesday, January 06, 2015
APHIS Provides Additional Information on Chronic Wasting Disease (CWD) Indemnity Requests January 5, 2015 05:26 PM EST
when an industry is catering to the public, with products which can risk human and animal health, in my opinion, you should have NO property rights. you should not be able to hide behind property rights when you are clearly risking human and animal health from your product, or the way you handle that product. if you are going to raise, grow, produce a product for the consumer, you have an obligation NOT to risk the public domain, public property, and or the wild animal populations. just my opinion. ...
Wednesday, January 28, 2015
Another new prion disease: relationship with central and peripheral amyloidoses
here we go again...
spontaneous atypical BSE ???
if that's the case, then France is having one hell of an epidemic of atypical BSE, probably why they stopped testing for BSE, problem solved $$$
As of December 2011, around 60 atypical BSE cases have currently been reported in 13 countries, *** with over one third in France.
so 20 cases of atypical BSE in France, compared to the remaining 40 cases in the remaining 12 Countries, divided by the remaining 12 Countries, about 3+ cases per country, besides Frances 20 cases. you cannot explain this away with any spontaneous BSe. ...TSS
Sunday, October 5, 2014
France stops BSE testing for Mad Cow Disease
Thursday, July 24, 2014
*** Protocol for further laboratory investigations into the distribution of infectivity of Atypical BSE SCIENTIFIC REPORT OF EFSA New protocol for Atypical BSE investigations
Monday, December 1, 2014
Germany Bovine Spongiform Encephalopathy BSE CJD TSE Prion disease A Review December 1, 2014
Wednesday, January 28, 2015
BOVINE HEPARIN POSITION STATEMENT ON THE REINTRODUCTION and POTENTIAL BSE TSE PRION RISK FACTORS THEREFROM
Thursday, January 29, 2015
Identification of H-type BSE in Portugal
Thursday, January 29, 2015
OIE REPORT Bovine spongiform encephalopathy Prion (atypical BSE type H), Norway Information received on 29/01/2015
Tuesday, December 16, 2014
Evidence for zoonotic potential of ovine scrapie prions
Hervé Cassard,1, n1 Juan-Maria Torres,2, n1 Caroline Lacroux,1, Jean-Yves Douet,1, Sylvie L. Benestad,3, Frédéric Lantier,4, Séverine Lugan,1, Isabelle Lantier,4, Pierrette Costes,1, Naima Aron,1, Fabienne Reine,5, Laetitia Herzog,5, Juan-Carlos Espinosa,2, Vincent Beringue5, & Olivier Andréoletti1, Affiliations Contributions Corresponding author Journal name: Nature Communications Volume: 5, Article number: 5821 DOI: doi:10.1038/ncomms6821 Received 07 August 2014 Accepted 10 November 2014 Published 16 December 2014 Article tools Citation Reprints Rights & permissions Article metrics
Although Bovine Spongiform Encephalopathy (BSE) is the cause of variant Creutzfeldt Jakob disease (vCJD) in humans, the zoonotic potential of scrapie prions remains unknown. Mice genetically engineered to overexpress the human prion protein (tgHu) have emerged as highly relevant models for gauging the capacity of prions to transmit to humans. These models can propagate human prions without any apparent transmission barrier and have been used used to confirm the zoonotic ability of BSE. Here we show that a panel of sheep scrapie prions transmit to several tgHu mice models with an efficiency comparable to that of cattle BSE. The serial transmission of different scrapie isolates in these mice led to the propagation of prions that are phenotypically identical to those causing sporadic CJD (sCJD) in humans. These results demonstrate that scrapie prions have a zoonotic potential and raise new questions about the possible link between animal and human prions.
Subject terms: Biological sciences• Medical research At a glance
why do we not want to do TSE transmission studies on chimpanzees $
5. A positive result from a chimpanzee challenged severly would likely create alarm in some circles even if the result could not be interpreted for man. I have a view that all these agents could be transmitted provided a large enough dose by appropriate routes was given and the animals kept long enough. Until the mechanisms of the species barrier are more clearly understood it might be best to retain that hypothesis.
1: J Infect Dis 1980 Aug;142(2):205-8
Oral transmission of kuru, Creutzfeldt-Jakob disease, and scrapie to nonhuman primates.
Gibbs CJ Jr, Amyx HL, Bacote A, Masters CL, Gajdusek DC.
Kuru and Creutzfeldt-Jakob disease of humans and scrapie disease of sheep and goats were transmitted to squirrel monkeys (Saimiri sciureus) that were exposed to the infectious agents only by their nonforced consumption of known infectious tissues. The asymptomatic incubation period in the one monkey exposed to the virus of kuru was 36 months; that in the two monkeys exposed to the virus of Creutzfeldt-Jakob disease was 23 and 27 months, respectively; and that in the two monkeys exposed to the virus of scrapie was 25 and 32 months, respectively. Careful physical examination of the buccal cavities of all of the monkeys failed to reveal signs or oral lesions. One additional monkey similarly exposed to kuru has remained asymptomatic during the 39 months that it has been under observation.
The successful transmission of kuru, Creutzfeldt-Jakob disease, and scrapie by natural feeding to squirrel monkeys that we have reported provides further grounds for concern that scrapie-infected meat may occasionally give rise in humans to Creutzfeldt-Jakob disease.
Recently the question has again been brought up as to whether scrapie is transmissible to man. This has followed reports that the disease has been transmitted to primates. One particularly lurid speculation (Gajdusek 1977) conjectures that the agents of scrapie, kuru, Creutzfeldt-Jakob disease and transmissible encephalopathy of mink are varieties of a single "virus". The U.S. Department of Agriculture concluded that it could "no longer justify or permit scrapie-blood line and scrapie-exposed sheep and goats to be processed for human or animal food at slaughter or rendering plants" (ARC 84/77)" The problem is emphasised by the finding that some strains of scrapie produce lesions identical to the once which characterise the human dementias"
Whether true or not. the hypothesis that these agents might be transmissible to man raises two considerations. First, the safety of laboratory personnel requires prompt attention. Second, action such as the "scorched meat" policy of USDA makes the solution of the acrapie problem urgent if the sheep industry is not to suffer grievously.
Nature. 1972 Mar 10;236(5341):73-4.
Transmission of scrapie to the cynomolgus monkey (Macaca fascicularis).
Gibbs CJ Jr, Gajdusek DC.
Nature 236, 73 - 74 (10 March 1972); doi:10.1038/236073a0
Transmission of Scrapie to the Cynomolgus Monkey (Macaca fascicularis)
C. J. GIBBS jun. & D. C. GAJDUSEK
National Institute of Neurological Diseases and Stroke, National Institutes of Health, Bethesda, Maryland
SCRAPIE has been transmitted to the cynomolgus, or crab-eating, monkey (Macaca fascicularis) with an incubation period of more than 5 yr from the time of intracerebral inoculation of scrapie-infected mouse brain. The animal developed a chronic central nervous system degeneration, with ataxia, tremor and myoclonus with associated severe scrapie-like pathology of intensive astroglial hypertrophy and proliferation, neuronal vacuolation and status spongiosus of grey matter. The strain of scrapie virus used was the eighth passage in Swiss mice (NIH) of a Compton strain of scrapie obtained as ninth intracerebral passage of the agent in goat brain, from Dr R. L. Chandler (ARC, Compton, Berkshire).
What if you can catch old-fashioned CJD by eating meat from a sheep infected with scrapie?
28 Mar 01
Like lambs to the slaughter
31 March 2001
by Debora MacKenzie Magazine issue 2284.
FOUR years ago, Terry Singeltary watched his mother die horribly from a degenerative brain disease. Doctors told him it was Alzheimer's, but Singeltary was suspicious. The diagnosis didn't fit her violent symptoms, and he demanded an autopsy. It showed she had died of sporadic Creutzfeldt-Jakob disease.
Most doctors believe that sCJD is caused by a prion protein deforming by chance into a killer. But Singeltary thinks otherwise. He is one of a number of campaigners who say that some sCJD, like the variant CJD related to BSE, is caused by eating meat from infected animals. Their suspicions have focused on sheep carrying scrapie, a BSE-like disease that is widespread in flocks across Europe and North America.
Now scientists in France have stumbled across new evidence that adds weight to the campaigners' fears. To their complete surprise, the researchers found that one strain of scrapie causes the same brain damage in mice as sCJD.
"This means we cannot rule out that at least some sCJD may be caused by some strains of scrapie," says team member Jean-Philippe Deslys of the French Atomic Energy Commission's medical research laboratory in Fontenay-aux-Roses, south-west of Paris. Hans Kretschmar of the University of Göttingen, who coordinates CJD surveillance in Germany, is so concerned by the findings that he now wants to trawl back through past sCJD cases to see if any might have been caused by eating infected mutton or lamb.
Scrapie has been around for centuries and until now there has been no evidence that it poses a risk to human health. But if the French finding means that scrapie can cause sCJD in people, countries around the world may have overlooked a CJD crisis to rival that caused by BSE.
Deslys and colleagues were originally studying vCJD, not sCJD. They injected the brains of macaque monkeys with brain from BSE cattle, and from French and British vCJD patients. The brain damage and clinical symptoms in the monkeys were the same for all three. Mice injected with the original sets of brain tissue or with infected monkey brain also developed the same symptoms.
As a control experiment, the team also injected mice with brain tissue from people and animals with other prion diseases: a French case of sCJD; a French patient who caught sCJD from human-derived growth hormone; sheep with a French strain of scrapie; and mice carrying a prion derived from an American scrapie strain. As expected, they all affected the brain in a different way from BSE and vCJD. But while the American strain of scrapie caused different damage from sCJD, the French strain produced exactly the same pathology.
"The main evidence that scrapie does not affect humans has been epidemiology," says Moira Bruce of the neuropathogenesis unit of the Institute for Animal Health in Edinburgh, who was a member of the same team as Deslys. "You see about the same incidence of the disease everywhere, whether or not there are many sheep, and in countries such as New Zealand with no scrapie." In the only previous comparisons of sCJD and scrapie in mice, Bruce found they were dissimilar.
But there are more than 20 strains of scrapie, and six of sCJD. "You would not necessarily see a relationship between the two with epidemiology if only some strains affect only some people," says Deslys. Bruce is cautious about the mouse results, but agrees they require further investigation. Other trials of scrapie and sCJD in mice, she says, are in progress.
People can have three different genetic variations of the human prion protein, and each type of protein can fold up two different ways. Kretschmar has found that these six combinations correspond to six clinical types of sCJD: each type of normal prion produces a particular pathology when it spontaneously deforms to produce sCJD.
But if these proteins deform because of infection with a disease-causing prion, the relationship between pathology and prion type should be different, as it is in vCJD. "If we look at brain samples from sporadic CJD cases and find some that do not fit the pattern," says Kretschmar, "that could mean they were caused by infection."
There are 250 deaths per year from sCJD in the US, and a similar incidence elsewhere. Singeltary and other US activists think that some of these people died after eating contaminated meat or "nutritional" pills containing dried animal brain. Governments will have a hard time facing activists like Singeltary if it turns out that some sCJD isn't as spontaneous as doctors have insisted.
Deslys's work on macaques also provides further proof that the human disease vCJD is caused by BSE. And the experiments showed that vCJD is much more virulent to primates than BSE, even when injected into the bloodstream rather than the brain. This, says Deslys, means that there is an even bigger risk than we thought that vCJD can be passed from one patient to another through contaminated blood transfusions and surgical instruments.
Tuesday, December 23, 2014
*** FDA PART 589 -- SUBSTANCES PROHIBITED FROM USE IN ANIMAL FOOD OR FEED VIOLATIONS OFFICIAL ACTION INDICATED OAI UPDATE DECEMBER 2014 BSE TSE PRION
CWD TO HUMANS, AND RISK FACTORS THERE FROM (see latest science)
Tuesday, November 04, 2014
*** Six-year follow-up of a point-source exposure to CWD contaminated venison in an Upstate New York community: risk behaviours and health outcomes 2005–2011
Friday, December 5, 2014
*** SPECIAL ALERT The OIE recommends strengthening animal disease surveillance worldwide OIE
BSE TSE PRION AKA MAD COW DISEASE ? ‘’the silence was deafening’’ ...tss
Comment from Terry Singeltary Sr.
This is a Comment on the Animal and Plant Health Inspection Service (APHIS) Notice: Agency Information Collection Activities; Proposals, Submissions, and Approvals: Bovine Spongiform Encephalopathy; Importation of Animals and Animal Products
For related information, Open Docket Folder
Docket No. APHIS-2014-0107 Bovine Spongiform Encephalopathy; Importation of Animals and Animal Products Singeltary Submission ;
I believe that there is more risk to the world from Transmissible Spongiform Encephalopathy TSE prion aka mad cow type disease now, coming from the United States and all of North America, than there is risk coming to the USA and North America, from other Countries. I am NOT saying I dont think there is any risk for the BSE type TSE prion coming from other Countries, I am just saying that in 2015, why is the APHIS/USDA/FSIS/FDA still ignoring these present mad cow risk factors in North America like they are not here?
North America has more strains of TSE prion disease, in more species (excluding zoo animals in the early BSE days, and excluding the Feline TSE and or Canine TSE, because they dont look, and yes, there has been documented evidence and scientific studies, and DEFRA Hound study, that shows the canine spongiform encephalopathy is very possible, if it has not already happened, just not documented), then any other Country in the world. Mink TME, Deer Elk cervid CWD (multiple strains), cBSE cattle, atypical L-type BSE cattle, atypical H-type BSE cattle, atyical HG type BSE cow (the only cow documented in the world to date with this strain), typical sheep goat Scrapie (multiple strains), and the atypical Nor-98 Scrapie, which has been linked to sporadic CJD, Nor-98 atypical Scrapie has spread from coast to coast. sporadic CJD on the rise, with different strains mounting, victims becoming younger, with the latest nvCJD human mad cow case being documented in Texas again, this case, NOT LINKED TO EUROPEAN TRAVEL CDC.
typical BSE can propagate as nvCJD and or sporadic CJD (Collinge et al), and sporadic CJD has now been linked to atypical BSE, Scrapie and atypical Scrapie, and scientist are very concerned with CWD TSE prion in the Cervid populations. in my opinion, the BSE MRR policy, which overtook the BSE GBR risk assessments for each country, and then made BSE confirmed countries legal to trade mad cow disease, which was all brought forth AFTER that fateful day December 23, 2003, when the USA lost its gold card i.e. BSE FREE status, thats the day it all started. once the BSE MRR policy was shoved down every countries throat by USDA inc and the OIE, then the legal trading of Scrapie was validated to be a legal trading commodity, also shoved through by the USDA inc and the OIE, the world then lost 30 years of attempted eradication of the BSE TSE prion disease typical and atypical strains, and the BSE TSE Prion aka mad cow type disease was thus made a legal trading commodity, like it or not. its all about money now folks, trade, to hell with human health with a slow incubating disease, that is 100% fatal once clinical, and forget the fact of exposure, sub-clinical infection, and friendly fire there from i.e. iatrogenic TSE prion disease, the pass it forward mode of the TSE PRION aka mad cow type disease. its all going to be sporadic CJD or sporadic ffi, or sporadic gss, or now the infamous VPSPr. ...problem solved $$$
the USDA/APHIS/FSIS/FDA triple mad cow BSE firewall, well, that was nothing but ink on paper.
for this very reason I believe the BSE MRR policy is a total failure, and that this policy should be immediately withdrawn, and set back in place the BSE GBR Risk Assessments, with the BSE GBR risk assessments set up to monitor all TSE PRION disease in all species of animals, and that the BSE GBR risk assessments be made stronger than before.
lets start with the recent notice that beef from Ireland will be coming to America.
Ireland confirmed around 1655 cases of mad cow disease. with the highest year confirming about 333 cases in 2002, with numbers of BSE confirmed cases dropping from that point on, to a documentation of 1 confirmed case in 2013, to date. a drastic decrease in the feeding of cows to cows i.e. the ruminant mad cow feed ban, and the enforcement of that ban, has drastically reduced the number of BSE cases in Europe, minus a few BABs or BARBs. a far cry from the USDA FDA triple BSE firewall, which was nothing more than ink on paper, where in 2007, in one week recall alone, some 10 MILLION POUNDS OF BANNED POTENTIAL MAD COW FEED WENT OUT INTO COMMERCE IN THE USA. this is 10 years post feed ban. in my honest opinion, due to the blatant cover up of BSE TSE prion aka mad cow disease in the USA, we still have no clue as to the true number of cases of BSE mad cow disease in the USA or North America as a whole. ...just saying.
Number of reported cases of bovine spongiform encephalopathy (BSE) in farmed cattle worldwide* (excluding the United Kingdom)
snip...please see attached pdf file, with references of breaches in the USA triple BSE mad cow firewalls, and recent science on the TSE prion disease. ...TSS
No documents available.
Sunday, January 11, 2015
Docket No. APHIS-2014-0107 Bovine Spongiform Encephalopathy; Importation of Animals and Animal Products Singeltary Submission
*** HUMAN MAD COW DISEASE nvCJD TEXAS CASE NOT LINKED TO EUROPEAN TRAVEL CDC ***
Sunday, November 23, 2014
*** Confirmed Variant Creutzfeldt-Jakob Disease (variant CJD) Case in Texas in June 2014 confirmed as USA case NOT European
the patient had resided in Kuwait, Russia and Lebanon. The completed investigation did not support the patient's having had extended travel to European countries, including the United Kingdom, or travel to Saudi Arabia. The specific overseas country where this patient’s infection occurred is less clear largely because the investigation did not definitely link him to a country where other known vCJD cases likely had been infected.
Sunday, December 14, 2014
*** ALERT new variant Creutzfeldt Jakob Disease nvCJD or vCJD, sporadic CJD strains, TSE prion aka Mad Cow Disease United States of America Update December 14, 2014 Report
Wednesday, January 28, 2015
Another new prion disease: relationship with central and peripheral amyloidoses here we go again...
Thursday, January 15, 2015
41-year-old Navy Commander with sporadic Creutzfeldt–Jakob disease CJD TSE Prion: Case Report
Subject: *** Becky Lockhart 46, Utah’s first female House speaker, dies diagnosed with the extremely rare Creutzfeldt-Jakob disease aka mad cow type disease
what is CJD ? just ask USDA inc., and the OIE, they are still feeding the public and the media industry fed junk science that is 30 years old.
why doesn’t some of you try reading the facts, instead of rubber stamping everything the USDA inc says.
sporadic CJD has now been linked to BSE aka mad cow disease, Scrapie, and there is much concern now for CWD and risk factor for humans.
My sincere condolences to the family and friends of the House Speaker Becky Lockhart. I am deeply saddened hear this.
with that said, with great respect, I must ask each and every one of you Politicians that are so deeply saddened to hear of this needless death of the Honorable House Speaker Becky Lockhart, really, cry me a friggen river. I am seriously going to ask you all this...I have been diplomatic for about 17 years and it has got no where. people are still dying. so, are you all stupid or what??? how many more need to die ??? how much is global trade of beef and other meat products that are not tested for the TSE prion disease, how much and how many bodies is this market worth?
Saturday, January 17, 2015
*** Becky Lockhart 46, Utah’s first female House speaker, dies diagnosed with the extremely rare Creutzfeldt-Jakob disease
Thursday, January 22, 2015
Transmission properties of atypical Creutzfeldt-Jakob disease: a clue to disease etiology?
Tuesday, December 30, 2014
TSEAC USA Reason For Recalls Blood products, collected from a donors considered to be at increased risk for Creutzfeldt-Jakob Disease (CJD), were distributed END OF YEAR REPORT 2014
who’s kidding whom $$$ i.e. USDA INC AND THE OIE
***Moreover, L-BSE has been transmitted more easily to transgenic mice overexpressing a human PrP [13,14] or to primates [15,16] than C-BSE.
***It has been suggested that some sporadic CJD subtypes in humans may result from an exposure to the L-BSE agent.
*** Lending support to this hypothesis, pathological and biochemical similarities have been observed between L-BSE and an sCJD subtype (MV genotype at codon 129 of PRNP) , and between L-BSE infected non-human primate and another sCJD subtype (MM genotype) .
Monday, October 10, 2011
EFSA Journal 2011 The European Response to BSE: A Success Story
EFSA and the European Centre for Disease Prevention and Control (ECDC) recently delivered a scientific opinion on any possible epidemiological or molecular association between TSEs in animals and humans (EFSA Panel on Biological Hazards (BIOHAZ) and ECDC, 2011). This opinion confirmed Classical BSE prions as the only TSE agents demonstrated to be zoonotic so far
*** but the possibility that a small proportion of human cases so far classified as "sporadic" CJD are of zoonotic origin could not be excluded.
*** Moreover, transmission experiments to non-human primates suggest that some TSE agents in addition to Classical BSE prions in cattle (namely L-type Atypical BSE, Classical BSE in sheep, transmissible mink encephalopathy (TME) and chronic wasting disease (CWD) agents) might have zoonotic potential.
Thursday, August 12, 2010
Seven main threats for the future linked to prions
The TSE road map defining the evolution of European policy for protection against prion diseases is based on a certain numbers of hypotheses some of which may turn out to be erroneous. In particular, a form of BSE (called atypical Bovine Spongiform Encephalopathy), recently identified by systematic testing in aged cattle without clinical signs, may be the origin of classical BSE and thus potentially constitute a reservoir, which may be impossible to eradicate if a sporadic origin is confirmed.
*** Also, a link is suspected between atypical BSE and some apparently sporadic cases of Creutzfeldt-Jakob disease in humans.
*** These atypical BSE cases constitute an unforeseen first threat that could sharply modify the European approach to prion diseases.
Terry S. Singeltary Sr.
P.O. Box 42
Bacliff, Texas USA 77518