Public health risks from subclinical variant CJD
Public health risks from subclinical variant CJD
Abigail B. Diack, Robert G. Will, Jean C. Manson
Published: November 30, 2017
Citation: Diack AB, Will RG, Manson JC (2017) Public health risks from subclinical variant CJD. PLoS Pathog 13(11): e1006642. https://doi.org/10.1371/journal.ppat.1006642
Editor: Heather L. True, Washington University School of Medicine, UNITED STATES
Published: November 30, 2017
Copyright: © 2017 Diack et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Funding: The Roslin Institute receives funding from the Biotechnology and Biological Sciences Research Council (BBSRC) (BB/J004332/1). The Diack and Manson laboratories are also funded by the National Institute for Health Research (NIHR) Policy Research Programme [Strain typing of vCJD; 007/0195]. The views expressed in this publication are those of the author(s) and not necessarily those of the NHS, the NIHR, the Department of Health, ‘arms’ length bodies, or other government departments. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing interests: The authors have declared that no competing interests exist. Introduction
Variant Creutzfeldt-Jakob disease (vCJD) is a zoonotic prion disease thought to have been transmitted to humans through the consumption of food products contaminated with bovine spongiform encephalopathy (BSE) in the 1980s and/or early 1990s. As with all prion disorders, it is a fatal neurodegenerative disease arising from conversion of the normal cellular form of the prion protein PrPC, encoded by the prion gene (PRNP), to an abnormal form associated with disease (PrPSc). Prion diseases have long asymptomatic incubation periods ranging from years to decades. Extensive studies involving both natural and experimental animal diseases have demonstrated that infectivity is present during the subclinical phase and may be transmitted between individuals. While the cases of clinical vCJD currently appear to be in decline, one of the current challenges is defining the prevalence of subclinical disease and the risk this poses to both individuals and the general population.
1. vCJD: Current perspective
In 1996, the first cases of vCJD were identified through systematic surveillance in the United Kingdom in collaboration with other European countries. vCJD typically occurs in young adults, and susceptibility is associated with the codon 129 polymorphism of PRNP (methionine [M]/valine [V]), with 177 out of 178 clinical cases being 129MM [1]. However, experimental transmission studies indicate that all genotypes may be susceptible and that 129MV and 129VV individuals may have long asymptomatic incubation periods [2]. Although the annual number of deaths due to vCJD peaked in 2000 with 28 deaths, this has since decreased, with only two deaths since 2011; one in 2013, and one in 2016 [1]. However, the latest case, in 2016, is the first instance of probable and/or definite clinical vCJD in a 129MV individual, raising concerns that a second wave of vCJD may occur in individuals of this genotype [1].
In addition to primary cases, thought to be directly acquired from BSE, three clinical cases of vCJD have been identified in 129MM individuals who had received nonleucoreduced red cell concentrates from UK donors who were asymptomatic at the time of donation but later died of vCJD. In addition, evidence of subclinical infection has been found in two other individuals, both of whom had a 129MV genotype [3]. One of these asymptomatic individuals showed no evidence of PrPSc in the brain, but evidence of PrPSc was identified in the spleen and a cervical lymph node [4]. Bioassay of the spleen material in wild-type and transgenic mice expressing human PrP (129MM) confirmed that the spleen carried vCJD infectivity (Table 1) [5]. Additional studies that have utilised protein misfolding cyclic amplification (PMCA; a protein amplification technique analogous to PCR that measures prion seeding activity) have also provided evidence of widespread prion seeding activity in a range of tissues in the asymptomatic 129MV individual (Table 1) [6].
Table 1. Tissues identified as containing abnormal PrP and/or infectivity in clinical and subclinical vCJD patients.
2. Abnormal PrP and transmission potential
Understanding the association between the presence of PrPSc and infectivity is essential in order to estimate disease prevalence and manage transmission risks. Retrospective appendix studies have indicated that 1 in 2,000 individuals have evidence of abnormal PrP in the appendix. The first studies of paraffin-embedded appendixes from preclinical vCJD patients demonstrated that abnormal PrP can be detected at least two years before clinical symptoms become apparent [7]. The first retrospective study reported a prevalence of approximately 1 in 4,000 individuals with abnormal PrP in their appendixes; of the three positive specimens identified, two were 129VV (Table 2) [8,9]. Two larger studies were subsequently performed. Appendix II and III both found a prevalence of approximately 1 in 2,000. Appendix II identified 16 positive samples that included a higher proportion of 129VV when compared with the normal population distribution and confirmed clinical cases of vCJD (Table 2) [10]. Appendix III was conducted on specimens that had been removed either prior to the BSE crisis or from individuals who were born in 1996 or later, at a time when food safety measures had been fully implemented. In this study, seven specimens containing abnormal PrP deposits were identified (Table 2) [11], and this raises questions about the interpretation of the abnormal PrP in relation to vCJD infection, particularly in those cohorts with presumably limited exposure to BSE. It is uncertain whether the positive immunohistochemical staining observed is vCJD specific, although such staining has not been observed in sporadic Creutzfeldt-Jakob disease (sCJD) [12]. One interpretation is that the period of human exposure to BSE was more extended than previously thought. These considerations are important for public health because individuals subclinically infected with vCJD may have the potential to transmit disease to others [8–10].
Table 2. Summary of the appendix survey results.
3. Subclinical prion disease
Subclinical disease is a well-studied phenomenon in prion diseases. Animal models demonstrate that during a long asymptomatic period, the level of infectivity increases in peripheral and central nervous system (CNS) tissue well before the onset of clinical disease [13]. During this period, infected tissues pose a risk of onward transmission, for example in humans via tissue transplant, contaminated surgical instruments, or infected blood.
A number of animal studies have investigated blood as a route of transmission of prion disease [3]. Seminal studies in sheep models of prion disease demonstrated that BSE could be transmitted via blood transfusion [14]. Further studies demonstrated that all blood components were capable of transmitting disease during the subclinical period [15]. The blood-transfusion–related human cases demonstrate that individuals of the 129MM genotype can transmit infectivity prior to developing clinical signs of disease.
Although the blood-transfusion–related cases of vCJD provide evidence of subclinical transmission, we still do not know at which point and in which tissues individuals first become infectious nor whether this will vary between codon 129 genotypes. Assessing the risk of iatrogenic transmission associated with subclinical vCJD is required to ascertain the potential for the transmission of disease between individuals.
4. Detecting subclinical disease
Although abnormal PrP can be detected by immunohistochemistry or seeding activity in a number of tissues from asymptomatic individuals, blood or urine are the only practicable substrates for the premortem identification of infected individuals [6]. A number of tests with varying specificity and sensitivity have been developed in order to detect vCJD infection by using blood or plasma from vCJD patients [16,17]. Recently, a test utilising a combination of a plasminogen bead capture system and PMCA that consistently detected vCJD prions from clinical vCJD cases with 100% sensitivity and 100% diagnostic specificity was developed [18]. This test also demonstrated an ability to detect prions in blood plasma from two subclinical blood donors (both 129MM); 1.3 and 2.6 years before clinical onset of disease. It is, however, unknown whether this test can detect prions in the blood or plasma of individuals with other codon 129 genotypes.
5. Determining risks to the individual and the population
The data from the Appendix studies indicate that up to 1 in 2,000 individuals in the UK may be subclinical carriers of vCJD. Whether subclinical vCJD infection leads to clinical disease is unknown and may depend on the recipient’s genotype, age, route, and/or level of infection. It is also unknown whether the clinical manifestation of the disease will vary in different genetic backgrounds and whether these individuals can transmit disease. The uncertainty surrounding these issues can only be addressed by continued surveillance, appropriate risk management, and the development of highly sensitive and specific markers of infection. To date, the only evidence of transmission of vCJD between individuals is via blood transfusion.
Continued human surveillance is required in order to identify new cases of vCJD, to promptly recognise any changes in clinical and/or pathological phenotype and to determine whether there are other routes of secondary transmission. At present, a number of risk management strategies are in place to reduce the risk of human-to-human transmission through blood. In the UK, these include leucoreduction of blood donations, donor deferral, and plasma sourcing from abroad. The development of blood tests could aid in allowing screening of blood donations or testing at-risk individuals. Concomitant with these approaches is a need to continue research into determining the nature of infectivity and the level of infectivity throughout the natural course of vCJD infection. It is essential that we do not become complacent and continue both surveillance and risk management strategies in both human and animal prion diseases.
Acknowledgments
We apologise to all those whose studies we could not cite due to space limitation. We thank Emma Hunt for useful comments.
References
snip...
MONDAY, NOVEMBER 06, 2017
Experimental transfusion of variant CJD-infected blood reveals previously uncharacterised prion disorder in mice and macaque
''On secondary and tertiary transmissions, however, the proportion of PrPres positive animals gradually increased to almost 100%.
''Recent communications suggest that a similar situation might exist in other models of experimental exposure to prions involving swine32 and cattle33.''
''Experimental transfusion of variant CJD-infected blood reveals previously uncharacterised prion disorder in mice and macaque''
WEDNESDAY, NOVEMBER 1, 2017
Blood-derived amyloid-β protein induces Alzheimer’s disease pathologies
MONDAY, OCTOBER 02, 2017
Creutzfeldt Jakob Disease United States of America USA and United Kingdom UK Increasing and Zoonotic Pontential From Different Species
THURSDAY, AUGUST 17, 2017
*** Monitoring the occurrence of emerging forms of Creutzfeldt-Jakob disease in the United States revisited 2017
Singeltary et al
THURSDAY, JULY 13, 2017
TEXAS CREUTZFELDT JAKOB DISEASE CJD TSE PRION
SUNDAY, NOVEMBER 23, 2014
Confirmed Variant Creutzfeldt-Jakob Disease (variant CJD) Case in Texas in June 2014 confirmed as USA case NOT European
SUNDAY, AUGUST 09, 2009
CJD...Straight talk with...James Ironside...and...Terry Singeltary... 2009
TUESDAY, AUGUST 18, 2009
BSE-The Untold Story - joe gibbs and singeltary 1999 - 2009
WEDNESDAY, NOVEMBER 22, 2017
NIH scientists and collaborators find infectious prion protein in skin of CJD patients
http://creutzfeldt-jakob-disease.blogspot.com/2017/11/nih-scientists-and-collaborators-find.html
NIH scientists and collaborators find infectious prion protein in skin of CJD patients
http://creutzfeldt-jakob-disease.blogspot.com/2017/11/nih-scientists-and-collaborators-find.html
WEDNESDAY, NOVEMBER 22, 2017
Prion seeding activity and infectivity in skin samples from patients with sporadic Creutzfeldt-Jakob disease
http://creutzfeldt-jakob-disease.blogspot.com/2017/11/prion-seeding-activity-and-infectivity.html
FRIDAY, AUGUST 11, 2017
Infectivity in bone marrow from sporadic CJD patients
Bioassays in transgenic mice expressing the human prion protein revealed the presence of unexpectedly high levels of infectivity in the bone marrow from seven out of eight sCJD cases. These findings may explain the presence of blood-borne infectivity in sCJD patients. They also suggest that the distribution of prion infectivity in peripheral tissues in sCJD patients could be wider than currently believed, with potential implications for the iatrogenic transmission risk of this disease.
THURSDAY, AUGUST 10, 2017
Minimise transmission risk of CJD and vCJD in healthcare settings Updated 10 August 2017
*** Transmission of Creutzfeldt-Jakob disease to a chimpanzee by electrodes contaminated during neurosurgery ***
Gibbs CJ Jr, Asher DM, Kobrine A, Amyx HL, Sulima MP, Gajdusek DC. Laboratory of Central Nervous System Studies, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892.
Stereotactic multicontact electrodes used to probe the cerebral cortex of a middle aged woman with progressive dementia were previously implicated in the accidental transmission of Creutzfeldt-Jakob disease (CJD) to two younger patients. The diagnoses of CJD have been confirmed for all three cases. More than two years after their last use in humans, after three cleanings and repeated sterilisation in ethanol and formaldehyde vapour, the electrodes were implanted in the cortex of a chimpanzee. Eighteen months later the animal became ill with CJD. This finding serves to re-emphasise the potential danger posed by reuse of instruments contaminated with the agents of spongiform encephalopathies, even after scrupulous attempts to clean them.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8006664&dopt=Abstract
sub-clinical shedding of tse prions via skin, saliva, feces, blood, body fluids, has been proven via different species. to what extent any such shedding and infectious materials there from, from sporadic cjd, only time and more transmission studies on those white TG $20k mice will tell...
(1) shedding of prions in saliva increases with time post-inoculation, but is common throughout the pre-clinical phase of disease;
Work on diagnosing CJD on skin biopsy was presented. It was also shown that potential infectivity could be found in such skin samples, but only using specific experimental techniques. It should be emphasised that there is no evidence that these diseases can be naturally transmitted by ordinary, even intimate, human contact.
Detection of Prion Seeds in Skins of Sporadic CJD Patients.
Disease-causing prions are believed to be concentrated in the central nervous system in most forms of prion disease other than variant CJD. Indeed, spinal fluid and brain tissue examinations form the bedrock of diagnosis in prion disease. However, it is known that skin of infected animals such as mice, sheep and the more exotic kudu are known to harbour prions, detected by traditional methods; prions were only detected in the skin of one single human case of variant CJD, but never in sporadic CJD. With the advent of highly sensitive and specific technology known as Real-Time Quaking-induce Conversion assay (RT-QuIC), scientists from Case Western University in Cleveland, Ohio set out to see if prion seeds can be detected in sporadic CJD patients. Not only did they manage to find prion seeds in the skin of sporadic CJD patients, but experimental mice injected with skin preparations from these patients caused the mice to come down with CJD; the traditional methods of detecting prions returned negative results. These observations raise the possibility using skin biopsy as a way of diagnosing CJD, and also the need to re-examine the distribution of prions in human tissues other than the central nervous system.
TUESDAY, JUNE 20, 2017
Prion 2017 Conference Transmissible prions in the skin of Creutzfeldt-Jakob disease patients
Scarification of the most superficial layers of the skin, and subsequent administration of prions, has been known for a long time to be a highly efficacious method of inducing prion disease22,23. Dendritic cells (professional antigen-presenting cells abundant in the skin) may become loaded with the infectious agent by this method; in fact, recent work has implicated dendritic cells as potential vectors of prions in oral24 and haematogenous spread25 of the agent. It is equally possible, however, that scarification induces direct neural entry of prions into skin nerve terminals. The latter hypothesis has not yet been studied in much detail, but it would help explain the remarkable speed with which CNS pathogenesis follows inoculation by this route: dermal inoculation of scarified mice yields typical latency periods of the disease that are similar to those obtained by intracerebral inoculation. The possibility of direct neural spread of the agent has also been suggested by a series of elegant experiments in the laboratories of Oldstone and Chesebro: transgenic mice that lack the endogenous prion gene but express a Prnp transgene exclusively in nervous tissue (under transcriptional control of the neuron-specific enolase regulatory elements) can be efficiently infected by the oral route despite lack of prion protein expression in lymphoid organs26. Of course, these experiments do not exclude the possibility that dendritic or other mobile cells may participate to neuro-invasion even if they do not express endogenous PrPC.
Scrapie infection can be established readily through skin scarification in immunocompetent but not immunodeficient mice
Scarification must be regarded as a highly effective means of transmission, given that these experiments have shown its efficiency to be little different to that of the i.p,, i.v. or p.v. routes. Indeed, it may be argued that scarification is probably more effective than the other routes because not all of the inoculum applied during the scarification procedure could possibly enter the host. It would appear therefore that the unhealed umbilical stump or skin lesions represent sites through which infectivity could efficiently gain access to sheep. The results also suggest that protection from skin trauma in the autopsy room or the laboratory, as is recommended customarily, is a sensible defence against acquiring CJD through occupational exposure.
***The occurrence of contact cases raises the possibility that transmission in families may be effected by an unusually virulent strain of the agent.
snip...see full text here;
MONDAY, OCTOBER 28, 2013
A Kiss of a Prion: New Implications for Oral Transmissibility
we are (in my opinion), exposed to the TSE prion in so many different ways in every day life, the potential for exposure and then becoming infected via taking care of a loved one with TSE prion disease, in my opinion risk factor there from is minimal, if proper precautions are taken, and even if they were not, the chance of becoming infected from a kiss, or casual contact is low, but I do not think it is zero, actually, far from it. I put this all together for a documentation of the known facts to date, of the potential casual human to human transmission. I did not put it together to scare anyone. with aerosol transmission of the TSE prion a reality now, infectivity in urine and feces and transmission there from being reality now with the TSE prion disease, I don’t see how anyone can rule _out_ the potential for transmission of the TSE prion via a kiss (a vehicle for transmission of the TSE prion via saliva), or even for a cut or open wound (all a cut is and transmission there from, is an crude inoculation of sorts, and inoculation has been proven to be an efficient mode of transmission for the TSE prion disease), even the eye, from either one of the body fluids now that how proven to be infections. I can’t see why we have such safety protocols for laboratory workers working with the TSE prion disease, but yet the same officials will say it’s o.k. for the public, friends, and or family members to do just the opposite with their loved ones when succumbing to the CJD TSE prion disease. don’t get me wrong, I did it too, and would probably do it again as far as kissing my mom. but science is science, and the transmission studies speak for themselves with the bodily fluids. simply put, which is all I was saying, we can’t say never, and or that none of these cases to date, have not been, and or will not be, a potential vehicle for transmission. I believe, and this is my opinion, that more concern for casual transmission with body fluids and materials there from, should be put forth to families with their loved ones, and I think that the safety protocols there from should be revised, to match that of the laboratory settings. again, this is my opinion. your opinion, and or others here, may read the same science and feel different out the findings. ...take care, kind regards, terry for decades science has shown that skin as a risk factor for tse prion.
It is further strongly recommended that impervious gloves be worn for activities that provide the opportunity for skin contact with infectious tissues and fluids.
kuru
Figure 25. All cooking. including that of human flesh from diseased kinsmen. was done in pits with steam made by pouring water over the hot stones, or cooked in bamboo cylinders in the hot ashes. Children participated in both the butchery and the handling of cooked meat, rubbing their soiled hands in their armpits or hair, and elsewhere on their bodies. They rarely or never washed. Infection with the kuru virus was most probably through the cuts and abrasions of the skin. or from nose-picking, rye (eye...tss) rubbing, or mucosal injury.
Sunday, October 27, 2013
A Kiss of a Prion: New Implications for Oral Transmissibility
WEDNESDAY, NOVEMBER 22, 2017
NIH scientists and collaborators find infectious prion protein in skin of CJD patients
WEDNESDAY, NOVEMBER 22, 2017
Prion seeding activity and infectivity in skin samples from patients with sporadic Creutzfeldt-Jakob disease
NEVER, ever, say never, when it comes to the tse prion aka mad cow type disease...kind regards, terry
Volume 2: Science
4. The link between BSE and vCJD
4.29 The evidence discussed above that vCJD is caused by BSE seems overwhelming. Uncertainties exist about the cause of CJD in farmers, their wives and in several abattoir workers. It seems that farmers at least might be at higher risk than others in the general population. 1 Increased ascertainment (ie, increased identification of cases as a result of greater awareness of the condition) seems unlikely, as other groups exposed to risk, such as butchers and veterinarians, do not appear to have been affected. The CJD in farmers seems to be similar to other sporadic CJD in age of onset, in respect to glycosylation patterns, and in strain-typing in experimental mice. Some farmers are heterozygous for the methionine/valine variant at codon 129, and their lymphoreticular system (LRS) does not contain the high levels of PrPSc found in vCJD. It remains a remote possibility that when older people contract CJD from BSE the resulting phenotype is like sporadic CJD and is distinct from the vCJD phenotype in younger people...end...BSE INQUIRY
2015, 2016, and 2017 TSE PRION UPDATED SCIENCE ZOONOSIS
O.05: Transmission of prions to primates after extended silent incubation periods: Implications for BSE and scrapie risk assessment in human populations
Emmanuel Comoy, Jacqueline Mikol, Valerie Durand, Sophie Luccantoni, Evelyne Correia, Nathalie Lescoutra, Capucine Dehen, and Jean-Philippe Deslys Atomic Energy Commission; Fontenay-aux-Roses, France
Prion diseases (PD) are the unique neurodegenerative proteinopathies reputed to be transmissible under field conditions since decades. The transmission of Bovine Spongiform Encephalopathy (BSE) to humans evidenced that an animal PD might be zoonotic under appropriate conditions. Contrarily, in the absence of obvious (epidemiological or experimental) elements supporting a transmission or genetic predispositions, PD, like the other proteinopathies, are reputed to occur spontaneously (atpical animal prion strains, sporadic CJD summing 80% of human prion cases). Non-human primate models provided the first evidences supporting the transmissibiity of human prion strains and the zoonotic potential of BSE. Among them, cynomolgus macaques brought major information for BSE risk assessment for human health (Chen, 2014), according to their phylogenetic proximity to humans and extended lifetime. We used this model to assess the zoonotic potential of other animal PD from bovine, ovine and cervid origins even after very long silent incubation periods.
*** We recently observed the direct transmission of a natural classical scrapie isolate to macaque after a 10-year silent incubation period,
***with features similar to some reported for human cases of sporadic CJD, albeit requiring fourfold long incubation than BSE. Scrapie, as recently evoked in humanized mice (Cassard, 2014),
***is the third potentially zoonotic PD (with BSE and L-type BSE),
***thus questioning the origin of human sporadic cases.
We will present an updated panorama of our different transmission studies and discuss the implications of such extended incubation periods on risk assessment of animal PD for human health.
===============
***thus questioning the origin of human sporadic cases***
===============
***our findings suggest that possible transmission risk of H-type BSE to sheep and human. Bioassay will be required to determine whether the PMCA products are infectious to these animals.
==============
Transmission data also revealed that several scrapie prions propagate in HuPrP-Tg mice with efficiency comparable to that of cattle BSE. While the efficiency of transmission at primary passage was low, subsequent passages resulted in a highly virulent prion disease in both Met129 and Val129 mice. Transmission of the different scrapie isolates in these mice leads to the emergence of prion strain phenotypes that showed similar characteristics to those displayed by MM1 or VV2 sCJD prion. These results demonstrate that scrapie prions have a zoonotic potential and raise new questions about the possible link between animal and human prions.
SPONTANEOUS ATYPICAL BOVINE SPONGIFORM ENCEPHALOPATHY
***Moreover, sporadic disease has never been observed in breeding colonies or primate research laboratories, most notably among hundreds of animals over several decades of study at the National Institutes of Health25, and in nearly twenty older animals continuously housed in our own facility.***
Saturday, April 23, 2016
Scrapie ZOONOSIS PRION CONFERENCE TOKYO 2016
*** SCRAPIE WS-01: Prion diseases in animals and zoonotic potential 2016 ***
Prion. 10:S15-S21. 2016 ISSN: 1933-6896 printl 1933-690X
2017 CHRONIC WASTING DISEASE CWD TSE PRION CERVID ZOONOISIS
Subject: ***CDC Now Recommends Strongly consider having the deer or elk tested for CWD before you eat the meat
CDC Now Recommends Strongly consider having the deer or elk tested for CWD before you eat the meat
Chronic Wasting Disease (CWD)
Prevention
If CWD could spread to people, it would most likely be through eating of infected deer and elk. In a 2006-2007 CDC survey of U.S. residents, nearly 20 percent of those surveyed said they had hunted deer or elk and more than two-thirds said they had eaten venison or elk meat. However, to date, no CWD infections have been reported in people.
Hunters must consider many factors when determining whether to eat meat from deer and elk harvested from areas with CWD, including the level of risk they are willing to accept. Hunters harvesting wild deer and elk from areas with reported CWD should check state wildlife and public health guidance to see whether testing of animals is recommended or required in a given state or region. In areas where CWD is known to be present, CDC recommends that hunters strongly consider having those animals tested before eating the meat.
Tests for CWD are monitoring tools that some state wildlife officials use to look at the rates of CWD in certain animal populations. Testing may not be available in every state, and states may use these tests in different ways. A negative test result does not guarantee that an individual animal is not infected with CWD, but it does make it considerably less likely and may reduce your risk of exposure to CWD.
To be as safe as possible and decrease their potential risk of exposure to CWD, hunters should take the following steps when hunting in areas with CWD:
Do not shoot, handle or eat meat from deer and elk that look sick or are acting strangely or are found dead (road-kill). When field-dressing a deer: Wear latex or rubber gloves when dressing the animal or handling the meat. Minimize how much you handle the organs of the animal, particularly the brain or spinal cord tissues. Do not use household knives or other kitchen utensils for field dressing. Check state wildlife and public health guidance to see whether testing of animals is recommended or required. Recommendations vary by state, but information about testing is available from many state wildlife agencies. Strongly consider having the deer or elk tested for CWD before you eat the meat. If you have your deer or elk commercially processed, consider asking that your animal be processed individually to avoid mixing meat from multiple animals. If your animal tests positive for CWD, do not eat meat from that animal. The U.S. Department of Agriculture’s Animal and Plant Health Inspection Service regulates commercially farmed deer and elk. The agency operates a national CWD herd certification program. As part of the voluntary program, states and individual herd owners agree to meet requirements meant to decrease the risk of CWD in their herds. Privately owned herds that do not participate in the herd certification program may be at increased risk for CWD.
Page last reviewed: August 17, 2017 Page last updated: August 17, 2017 Content source: Centers for Disease Control and Prevention National Center for Emerging and Zoonotic Infectious Diseases (NCEZID) Division of High-Consequence Pathogens and Pathology (DHCPP)
> However, to date, no CWD infections have been reported in people.
key word here is 'reported'. science has shown that CWD in humans will look like sporadic CJD. SO, how can one assume that CWD has not already transmitted to humans? they can't, and it's as simple as that. from all recorded science to date, CWD has already transmitted to humans, and it's being misdiagnosed as sporadic CJD. ...terry
LOOKING FOR CWD IN HUMANS AS nvCJD or as an ATYPICAL CJD, LOOKING IN ALL THE WRONG PLACES $$$
*** These results would seem to suggest that CWD does indeed have zoonotic potential, at least as judged by the compatibility of CWD prions and their human PrPC target. Furthermore, extrapolation from this simple in vitro assay suggests that if zoonotic CWD occurred, it would most likely effect those of the PRNP codon 129-MM genotype and that the PrPres type would be similar to that found in the most common subtype of sCJD (MM1).***
Molecular Barriers to Zoonotic Transmission of Prions
*** chronic wasting disease, there was no absolute barrier to conversion of the human prion protein.
*** Furthermore, the form of human PrPres produced in this in vitro assay when seeded with CWD, resembles that found in the most common human prion disease, namely sCJD of the MM1 subtype.
TUESDAY, SEPTEMBER 12, 2017
CDC Now Recommends Strongly consider having the deer or elk tested for CWD before you eat the meat
Prion 2017 Conference Abstracts CWD
2017 PRION CONFERENCE
First evidence of intracranial and peroral transmission of Chronic Wasting Disease (CWD) into Cynomolgus macaques: a work in progress
Stefanie Czub1, Walter Schulz-Schaeffer2, Christiane Stahl-Hennig3, Michael Beekes4, Hermann Schaetzl5 and Dirk Motzkus6 1
University of Calgary Faculty of Veterinary Medicine/Canadian Food Inspection Agency; 2Universitatsklinikum des Saarlandes und Medizinische Fakultat der Universitat des Saarlandes; 3 Deutsches Primaten Zentrum/Goettingen; 4 Robert-Koch-Institut Berlin; 5 University of Calgary Faculty of Veterinary Medicine; 6 presently: Boehringer Ingelheim Veterinary Research Center; previously: Deutsches Primaten Zentrum/Goettingen
This is a progress report of a project which started in 2009. 21 cynomolgus macaques were challenged with characterized CWD material from white-tailed deer (WTD) or elk by intracerebral (ic), oral, and skin exposure routes. Additional blood transfusion experiments are supposed to assess the CWD contamination risk of human blood product. Challenge materials originated from symptomatic cervids for ic, skin scarification and partially per oral routes (WTD brain). Challenge material for feeding of muscle derived from preclinical WTD and from preclinical macaques for blood transfusion experiments. We have confirmed that the CWD challenge material contained at least two different CWD agents (brain material) as well as CWD prions in muscle-associated nerves.
Here we present first data on a group of animals either challenged ic with steel wires or per orally and sacrificed with incubation times ranging from 4.5 to 6.9 years at postmortem. Three animals displayed signs of mild clinical disease, including anxiety, apathy, ataxia and/or tremor. In four animals wasting was observed, two of those had confirmed diabetes. All animals have variable signs of prion neuropathology in spinal cords and brains and by supersensitive IHC, reaction was detected in spinal cord segments of all animals. Protein misfolding cyclic amplification (PMCA), real-time quaking-induced conversion (RT-QuiC) and PET-blot assays to further substantiate these findings are on the way, as well as bioassays in bank voles and transgenic mice.
At present, a total of 10 animals are sacrificed and read-outs are ongoing. Preclinical incubation of the remaining macaques covers a range from 6.4 to 7.10 years. Based on the species barrier and an incubation time of > 5 years for BSE in macaques and about 10 years for scrapie in macaques, we expected an onset of clinical disease beyond 6 years post inoculation.
PRION 2017 DECIPHERING NEURODEGENERATIVE DISORDERS
Subject: PRION 2017 CONFERENCE DECIPHERING NEURODEGENERATIVE DISORDERS VIDEO
PRION 2017 CONFERENCE DECIPHERING NEURODEGENERATIVE DISORDERS
*** PRION 2017 CONFERENCE VIDEO
TUESDAY, JUNE 13, 2017
PRION 2017 CONFERENCE ABSTRACT
First evidence of intracranial and peroral transmission of Chronic Wasting Disease (CWD) into Cynomolgus macaques: a work in progress
TUESDAY, JULY 04, 2017
*** PRION 2017 CONFERENCE ABSTRACTS ON CHRONIC WASTING DISEASE CWD TSE PRION ***
TUESDAY, JUNE 13, 2017
PRION 2017 CONFERENCE ABSTRACT Chronic Wasting Disease in European moose is associated with PrPSc features different from North American CWD
Wednesday, May 24, 2017
PRION2017 CONFERENCE VIDEO UPDATE 23 – 26 May 2017 Edinburgh UPDATE 1
SATURDAY, JULY 29, 2017
Risk Advisory Opinion: Potential Human Health Risks from Chronic Wasting Disease CFIA, PHAC, HC (HPFB and FNIHB), INAC, Parks Canada, ECCC and AAFC
Prion Infectivity in Fat of Deer with Chronic Wasting Disease▿
Brent Race#, Kimberly Meade-White#, Richard Race and Bruce Chesebro* + Author Affiliations
In mice, prion infectivity was recently detected in fat. Since ruminant fat is consumed by humans and fed to animals, we determined infectivity titers in fat from two CWD-infected deer. Deer fat devoid of muscle contained low levels of CWD infectivity and might be a risk factor for prion infection of other species.
Prions in Skeletal Muscles of Deer with Chronic Wasting Disease
Here bioassays in transgenic mice expressing cervid prion protein revealed the presence of infectious prions in skeletal muscles of CWD-infected deer, demonstrating that humans consuming or handling meat from CWD-infected deer are at risk to prion exposure.
*** WDA 2016 NEW YORK ***
We found that CWD adapts to a new host more readily than BSE and that human PrP was unexpectedly prone to misfolding by CWD prions. In addition, we investigated the role of specific regions of the bovine, deer and human PrP protein in resistance to conversion by prions from another species. We have concluded that the human protein has a region that confers unusual susceptibility to conversion by CWD prions.
Wildlife Disease Risk Communication Research Contributes to Wildlife Trust Administration Exploring perceptions about chronic wasting disease risks among wildlife and agriculture professionals and stakeholders
Zoonotic Potential of CWD Prions: An Update Prion 2016 Tokyo Zoonotic Potential of CWD Prions: An Update
Ignazio Cali1, Liuting Qing1, Jue Yuan1, Shenghai Huang2, Diane Kofskey1,3, Nicholas Maurer1, Debbie McKenzie4, Jiri Safar1,3,5, Wenquan Zou1,3,5,6, Pierluigi Gambetti1, Qingzhong Kong1,5,6
1Department of Pathology, 3National Prion Disease Pathology Surveillance Center, 5Department of Neurology, 6National Center for Regenerative Medicine, Case Western Reserve University, Cleveland, OH 44106, USA.
4Department of Biological Sciences and Center for Prions and Protein Folding Diseases, University of Alberta, Edmonton, Alberta, Canada,
2Encore Health Resources, 1331 Lamar St, Houston, TX 77010
Chronic wasting disease (CWD) is a widespread and highly transmissible prion disease in free-ranging and captive cervid species in North America. The zoonotic potential of CWD prions is a serious public health concern, but the susceptibility of human CNS and peripheral organs to CWD prions remains largely unresolved. We reported earlier that peripheral and CNS infections were detected in transgenic mice expressing human PrP129M or PrP129V. Here we will present an update on this project, including evidence for strain dependence and influence of cervid PrP polymorphisms on CWD zoonosis as well as the characteristics of experimental human CWD prions.
PRION 2016 TOKYO
In Conjunction with Asia Pacific Prion Symposium 2016
PRION 2016 Tokyo
Prion 2016
Cervid to human prion transmission
Kong, Qingzhong
Case Western Reserve University, Cleveland, OH, United States
Abstract
Prion disease is transmissible and invariably fatal. Chronic wasting disease (CWD) is the prion disease affecting deer, elk and moose, and it is a widespread and expanding epidemic affecting 22 US States and 2 Canadian provinces so far. CWD poses the most serious zoonotic prion transmission risks in North America because of huge venison consumption (>6 million deer/elk hunted and consumed annually in the USA alone), significant prion infectivity in muscles and other tissues/fluids from CWD-affected cervids, and usually high levels of individual exposure to CWD resulting from consumption of the affected animal among often just family and friends. However, we still do not know whether CWD prions can infect humans in the brain or peripheral tissues or whether clinical/asymptomatic CWD zoonosis has already occurred, and we have no essays to reliably detect CWD infection in humans. We hypothesize that:
(1) The classic CWD prion strain can infect humans at low levels in the brain and peripheral lymphoid tissues;
(2) The cervid-to-human transmission barrier is dependent on the cervid prion strain and influenced by the host (human) prion protein (PrP) primary sequence;
(3) Reliable essays can be established to detect CWD infection in humans;and
*** (4) CWD transmission to humans has already occurred. We will test these hypotheses in 4 Aims using transgenic (Tg) mouse models and complementary in vitro approaches.
Aim 1 will prove that the classical CWD strain may infect humans in brain or peripheral lymphoid tissues at low levels by conducting systemic bioassays in a set of "humanized" Tg mouse lines expressing common human PrP variants using a number of CWD isolates at varying doses and routes. Experimental "human CWD" samples will also be generated for Aim 3.
Aim 2 will test the hypothesis that the cervid-to-human prion transmission barrier is dependent on prion strain and influenced by the host (human) PrP sequence by examining and comparing the transmission efficiency and phenotypes of several atypical/unusual CWD isolates/strains as well as a few prion strains from other species that have adapted to cervid PrP sequence, utilizing the same panel of humanized Tg mouse lines as in Aim 1.
Aim 3 will establish reliable essays for detection and surveillance of CWD infection in humans by examining in details the clinical, pathological, biochemical and in vitro seeding properties of existing and future experimental "human CWD" samples generated from Aims 1-2 and compare them with those of common sporadic human Creutzfeldt-Jakob disease (sCJD) prions.
Aim 4 will attempt to detect clinical CWD-affected human cases by examining a significant number of brain samples from prion-affected human subjects in the USA and Canada who have consumed venison from CWD-endemic areas utilizing the criteria and essays established in Aim 3. The findings from this proposal will greatly advance our understandings on the potential and characteristics of cervid prion transmission in humans, establish reliable essays for CWD zoonosis and potentially discover the first case(s) of CWD infection in humans.
Public Health Relevance There are significant and increasing human exposure to cervid prions because chronic wasting disease (CWD, a widespread and highly infectious prion disease among deer and elk in North America) continues spreading and consumption of venison remains popular, but our understanding on cervid-to-human prion transmission is still very limited, raising public health concerns. This proposal aims to define the zoonotic risks of cervid prions and set up and apply essays to detect CWD zoonosis using mouse models and in vitro methods. The findings will greatly expand our knowledge on the potentials and characteristics of cervid prion transmission in humans, establish reliable essays for such infections and may discover the first case(s) of CWD infection in humans.
Funding Agency Agency National Institute of Health (NIH)
Institute National Institute of Neurological Disorders and Stroke (NINDS)
Type Research Project (R01)
Project # 1R01NS088604-01A1
Application # 9037884
Study Section Cellular and Molecular Biology of Neurodegeneration Study Section (CMND)
Program Officer Wong, May
Project Start 2015-09-30
Project End 2019-07-31
Budget Start 2015-09-30
Budget End 2016-07-31
Support Year 1
Fiscal Year 2015
Total Cost $337,507
Indirect Cost $118,756
Institution
Name Case Western Reserve University
Department Pathology
Type Schools of Medicine
DUNS # 077758407
City Cleveland
State OH
Country United States
Zip Code 44106
SATURDAY, DECEMBER 02, 2017 TEXAS
TAHC CWD TSE PRION Trace Herds INs and OUTs Summary Minutes of the 399th and 398th Commission Meeting – 8/22/2017 5/9/2017
FRIDAY, DECEMBER 01, 2017
TEXAS TAHC CWD TSE PRION SURVEILLANCE AND REPORTING UNDER QUESTION, 14 CAPTIVE CASES CWD DETECTED 2017 SO FAR
MONDAY, AUGUST 14, 2017
*** Texas Chronic Wasting Disease CWD TSE Prion History ***
*** PLEASE SEE THIS URGENT UPDATE ON CWD AND FEED ANIMAL PROTEIN ***
cwd to pig, orally ;
Research Project: TRANSMISSION, DIFFERENTIATION, AND PATHOBIOLOGY OF TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHIES
Location: Virus and Prion Research
Title: Disease-associated prion protein detected in lymphoid tissues from pigs challenged with the agent of chronic wasting disease
Author item Moore, Sarah item Kunkle, Robert item Kondru, Naveen item Manne, Sireesha item Smith, Jodi item Kanthasamy, Anumantha item West Greenlee, M item Greenlee, Justin
Submitted to: Prion Publication Type: Abstract Only Publication Acceptance Date: 3/15/2017 Publication Date: N/A Citation: N/A Interpretive Summary:
Technical Abstract: Aims: Chronic wasting disease (CWD) is a naturally-occurring, fatal neurodegenerative disease of cervids. We previously demonstrated that disease-associated prion protein (PrPSc) can be detected in the brain and retina from pigs challenged intracranially or orally with the CWD agent. In that study, neurological signs consistent with prion disease were observed only in one pig: an intracranially challenged pig that was euthanized at 64 months post-challenge. The purpose of this study was to use an antigen-capture immunoassay (EIA) and real-time quaking-induced conversion (QuIC) to determine whether PrPSc is present in lymphoid tissues from pigs challenged with the CWD agent.
Methods: At two months of age, crossbred pigs were challenged by the intracranial route (n=20), oral route (n=19), or were left unchallenged (n=9). At approximately 6 months of age, the time at which commercial pigs reach market weight, half of the pigs in each group were culled (<6 challenge="" groups="" month="" pigs="" remaining="" the="">6 month challenge groups) were allowed to incubate for up to 73 months post challenge (mpc). The retropharyngeal lymph node (RPLN) was screened for the presence of PrPSc by EIA and immunohistochemistry (IHC). The RPLN, palatine tonsil, and mesenteric lymph node (MLN) from 6-7 pigs per challenge group were also tested using EIA and QuIC.
Results: PrPSc was not detected by EIA and IHC in any RPLNs. All tonsils and MLNs were negative by IHC, though the MLN from one pig in the oral <6 5="" 6="" at="" by="" detected="" eia.="" examined="" group="" in="" intracranial="" least="" lymphoid="" month="" months="" of="" one="" pigs="" positive="" prpsc="" quic="" the="" tissues="" was="">6 months group, 5/6 pigs in the oral <6 4="" and="" group="" months="" oral="">6 months group. Overall, the MLN was positive in 14/19 (74%) of samples examined, the RPLN in 8/18 (44%), and the tonsil in 10/25 (40%). Conclusions:
This study demonstrates that PrPSc accumulates in lymphoid tissues from pigs challenged intracranially or orally with the CWD agent, and can be detected as early as 4 months after challenge.
CWD-infected pigs rarely develop clinical disease and if they do, they do so after a long incubation period. This raises the possibility that CWD-infected pigs could shed prions into their environment long before they develop clinical disease.
Furthermore, lymphoid tissues from CWD-infected pigs could present a potential source of CWD infectivity in the animal and human food chains.
CONFIDENTIAL
EXPERIMENTAL PORCINE SPONGIFORM ENCEPHALOPATHY
While this clearly is a cause for concern we should not jump to the conclusion that this means that pigs will necessarily be infected by bone and meat meal fed by the oral route as is the case with cattle. ...
we cannot rule out the possibility that unrecognised subclinical spongiform encephalopathy could be present in British pigs though there is no evidence for this: only with parenteral/implantable pharmaceuticals/devices is the theoretical risk to humans of sufficient concern to consider any action.
Our records show that while some use is made of porcine materials in medicinal products, the only products which would appear to be in a hypothetically ''higher risk'' area are the adrenocorticotrophic hormone for which the source material comes from outside the United Kingdom, namely America China Sweden France and Germany. The products are manufactured by Ferring and Armour. A further product, ''Zenoderm Corium implant'' manufactured by Ethicon, makes use of porcine skin - which is not considered to be a ''high risk'' tissue, but one of its uses is described in the data sheet as ''in dural replacement''. This product is sourced from the United Kingdom.....
snip...see much more here ;
WEDNESDAY, APRIL 05, 2017
Disease-associated prion protein detected in lymphoid tissues from pigs challenged with the agent of chronic wasting disease
MONDAY, AUGUST 14, 2017
Experimental transmission of the chronic wasting disease agent to swine after oral or intracranial inoculation
TUESDAY, APRIL 18, 2017
EXTREME USA FDA PART 589 TSE PRION FEED LOOP HOLE STILL EXIST, AND PRICE OF POKER GOES UP
FRIDAY, NOVEMBER 3, 2017
BSE MAD COW TSE PRION DISEASE PET FOOD FEED IN COMMERCE INDUSTRY VS TERRY S. SINGELTARY Sr. A REVIEW
''I have a neighbor who is a dairy farmer. He tells me that he knows of several farmers who feed their cattle expired dog food. These farmers are unaware of any dangers posed to their cattle from the pet food contents. For these farmers, the pet food is just another source of protein.''
IN CONFIDENCE
SATURDAY, NOVEMBER 4, 2017
FDA 589.2000, Section 21 C.F.R. Animal Proteins Prohibited in Ruminant Feed WARNING Letters and FEED MILL VIOLATIONS OBSERVATIONS 2017 to 2006
OFFICIAL REPORT U.K. GOVERNMENT DEFRA
What is the risk of chronic wasting disease being introduced into Great Britain? A Qualitative Risk Assessment October 2012
Several different animal feed products are imported into GB from North America. These include processed pet foods and consignments of unfinished feed ingredients for use in animal feed. The amount of imported feed, including pet food, that contains cervid protein is unknown and identified as a significant data gap. As non-ruminant animal feed may be produced with cervid protein (but not from positive CWD animals) in the United States (US), there is a greater than negligible risk that feed with cervid protein is imported from North America into GB. There is, however, uncertainty associated with this estimate.
snip...
In summary, given the volume of tourists, hunters and servicemen moving between GB and North America, the probability of at least one person travelling to/from a CWD affected area and, in doing so, contaminating their clothing, footwear and/or equipment prior to arriving in GB is greater than negligible. For deer hunters, specifically, the risk is likely to be greater given the increased contact with deer and their environment. However, there is significant uncertainty associated with these estimates.
snip...
Therefore, it is considered that farmed and park deer may have a higher probability of exposure to CWD transferred to the environment than wild deer given the restricted habitat range and higher frequency of contact with tourists and returning GB residents.
snip...
What is the risk of chronic wasting disease being introduced into Great Britain? A Qualitative Risk Assessment October 2012
Thursday, April 07, 2016
What is the risk of chronic wasting disease being introduced into Great Britain? An updated Qualitative Risk Assessment March 2016
TUESDAY, OCTOBER 17, 2017
EFSA asked to review risk from processed animal proteins in feed PIG PAP and CWD TSE Prion Oral Transmission
THURSDAY, JULY 13, 2017
EFSA BSE Sixty cases of mad cow disease since 2001 breached feed ban likely the cause
Scientists investigate origin of isolated BSE cases
FRIDAY, OCTOBER 06, 2017
Canada and USA Scrapie BSE TSE Prion Update October 5 2017
WEDNESDAY, OCTOBER 4, 2017
EFSA Scientific Report on the Assessment of the Geographical BSE-Risk (GBR) of the United States of America (USA) a review 2017
Thursday, November 16, 2017
Texas Natural Meats Recalls Beef Products Due To Possible Specified Risk Materials Contamination
WEDNESDAY, JULY 26, 2017
APHIS USDA Emerging Animal Disease Preparedness and Response Plan July 2017
2009 UPDATE ON ALABAMA AND TEXAS MAD COWS 2005 and 2006
ALABAMA MAD COW CASE
Saturday, August 14, 2010
BSE Case Associated with Prion Protein Gene Mutation (g-h-BSEalabama) and VPSPr PRIONPATHY
(see COPIOUS AMOUNTS OF mad cow feed in COMMERCE IN ALABAMA...TSS)
Texas BSE Investigation Final Epidemiology Report August 2005
State-Federal Team Responds to Texas BSE Case
JUNE 30, 2005
(please note 7+ month delay in final confirmation so the BSE MRR policy could be set in stone first. $$$...tss)
SEE ATTEMPTED COVER-UP BEFORE THE END AROUND BY FONG ET AL OF THE O.I.G
TUESDAY, JULY 18, 2017
USDA announces Alabama case of Bovine Spongiform Encephalopathy Alabama
THURSDAY, JULY 20, 2017
USDA OIE Alabama Atypical L-type BASE Bovine Spongiform Encephalopathy BSE animal feeds for ruminants rule, 21 CFR 589.200
SUNDAY, JULY 23, 2017
atypical L-type BASE Bovine Amyloidotic Spongiform Encephalopathy BSE TSE PRION
SUNDAY, JULY 23, 2017
Experimental Infection of Cattle With a Novel Prion Derived From Atypical H-Type Bovine Spongiform Encephalopathy
MONDAY, AUGUST 14, 2017
Experimental transmission of the chronic wasting disease agent to swine after oral or intracranial inoculation
THURSDAY, JULY 13, 2017
EFSA BSE Sixty cases of mad cow disease since 2001 breached feed ban likely the cause
Scientists investigate origin of isolated BSE cases
Diagnosis and Reporting of Creutzfeldt-Jakob Disease
Singeltary, Sr et al. JAMA.2001; 285: 733-734. Vol. 285 No. 6, February 14, 2001 JAMA Diagnosis and Reporting of Creutzfeldt-Jakob Disease
To the Editor:
In their Research Letter, Dr Gibbons and colleagues1 reported that the annual US death rate due to Creutzfeldt-Jakob disease (CJD) has been stable since 1985. These estimates, however, are based only on reported cases, and do not include misdiagnosed or preclinical cases. It seems to me that misdiagnosis alone would drastically change these figures. An unknown number of persons with a diagnosis of Alzheimer disease in fact may have CJD, although only a small number of these patients receive the postmortem examination necessary to make this diagnosis. Furthermore, only a few states have made CJD reportable. Human and animal transmissible spongiform encephalopathies should be reportable nationwide and internationally.
Terry S. Singeltary, Sr Bacliff, Tex
1. Gibbons RV, Holman RC, Belay ED, Schonberger LB. Creutzfeldt-Jakob disease in the United States: 1979-1998. JAMA. 2000;284:2322-2323.
Terry S. Singeltary Sr.
posted by Terry S. Singeltary Sr. | 9:34 PM
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