Clin Implant Dent Relat Res. 2011 Dec 15. doi: 10.1111/j.1708-8208.2011.00407.x. [Epub ahead of print]
Risk of Prion Disease Transmission through Bovine-Derived Bone Substitutes: A Systematic Review.
Kim Y, Nowzari H, Rich SK. Source Resident, Advanced Education in Periodontics Program, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, CA, USA professor, Clinical Dentistry and director, Advanced Education in Periodontics Program, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, CA, USA associate professor, Advanced Education in Periodontics Program, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, CA, USA.
Abstract Background:
Despite the causal association between variant Creutzfeldt - Jakob disease and bovine spongiform encephalopathy (BSE), bovine origin graft materials are widely used during dental surgical procedures. The aim of this study was to assess the risk of BSE transmission through anorganic bovine bone substitutes.
Methods: Electronic database of MEDLINE was searched to identify relevant studies regarding our focused questions, presence of BSE prion infectivity in raw bovine bone, BSE prion inactivation by bone substitute manufacturing process, protein contents in anorganic bovine bone substitutes, and validity of current BSE diagnostic methods. Search terms yielded 1,704 titles. After title/abstract screening and duplicates removal, 36 full-text articles were screened for inclusion.
Results: A total of 16 studies were included in the final analysis. No eligible studies were identified regarding the efficacy of BSE prion inactivation by the treatments used for anorganic bovine bone manufacturing. BSE infectivity and PrP(Sc) , pathological prion, were detected in bovine bone marrow and serum samples. Proteins were detected in Tutoplast® (bovine), Bio-Oss®, and tibia samples treated at the similar condition for Bio-Oss deproteinization. Inconsistent results of different BSE diagnostic tests were not unusual findings (Iwata et al. 2006; Arnold et al. 2007; Murayama et al. 2010), and a study by Balkema-Buschmann and colleagues showed an apparent discrepancy between BSE infectivity and detection of PrP(27-30), the current surrogate marker for prion disease infectivity. Conclusion: This review indicates that bovine-derived graft biomaterials may carry a risk of prion transmission to patients.
© 2011 Wiley Periodicals, Inc.
PMID: 22171533 [PubMed - as supplied by publisher]
Aerosols Transmit Prions to Immunocompetent and Immunodeficient Mice
Johannes Haybaeck1.¤a, Mathias Heikenwalder1.¤b, Britta Klevenz2., Petra Schwarz1, Ilan Margalith1, Claire Bridel1, Kirsten Mertz1,3, Elizabeta Zirdum2, Benjamin Petsch2, Thomas J. Fuchs4, Lothar Stitz2*, Adriano Aguzzi1* 1 Department of Pathology, Institute of Neuropathology, University Hospital Zurich, Zurich, Switzerland, 2 Institute of Immunology, Friedrich-Loeffler-Institut, Tu¨ bingen, Germany, 3 Department of Pathology, Clinical Pathology, University Hospital Zurich, Zurich, Switzerland, 4 Department of Computer Science, Machine Learning Laboratory, ETH Zurich, Zurich, Switzerland
Abstract
Prions, the agents causing transmissible spongiform encephalopathies, colonize the brain of hosts after oral, parenteral, intralingual, or even transdermal uptake. However, prions are not generally considered to be airborne. Here we report that inbred and crossbred wild-type mice, as well as tga20 transgenic mice overexpressing PrPC, efficiently develop scrapie upon exposure to aerosolized prions. NSE-PrP transgenic mice, which express PrPC selectively in neurons, were also susceptible to airborne prions. Aerogenic infection occurred also in mice lacking B- and T-lymphocytes, NK-cells, follicular dendritic cells or complement components. Brains of diseased mice contained PrPSc and transmitted scrapie when inoculated into further mice. We conclude that aerogenic exposure to prions is very efficacious and can lead to direct invasion of neural pathways without an obligatory replicative phase in lymphoid organs. This previously unappreciated risk for airborne prion transmission may warrant re-thinking on prion biosafety guidelines in research and diagnostic laboratories.
SNIP...
In summary, our results establish aerosols as a surprisingly efficient modality of prion transmission. This novel pathway of prion transmission is not only conceptually relevant for the field of prion research, but also highlights a hitherto unappreciated risk factor for laboratory personnel and personnel of the meat processing industry. In the light of these findings, it may be appropriate to revise current prion-related biosafety guidelines and health standards in diagnostic and scientific laboratories being potentially confronted with prion infected materials. While we did not investigate whether production of prion aerosols in nature suffices to cause horizontal prion transmission, the finding of prions in biological fluids such as saliva, urine and blood suggests that it may be worth testing this possibility in future studies.
Citation: Haybaeck J, Heikenwalder M, Klevenz B, Schwarz P, Margalith I, et al. (2011) Aerosols Transmit Prions to Immunocompetent and Immunodeficient Mice. PLoS Pathog 7(1): e1001257. doi:10.1371/journal.ppat.1001257 Editor: David Westaway, University of Alberta, Canada Received March 22, 2010; Accepted December 13, 2010; Published January 13, 2011
PLEASE SEE FULL TEXT, AND AGAIN, many thanks to PLOS for open access !!!
WHO Tables on Tissue Infectivity Distribution in Transmissible Spongiform Encephalopathies Updated 2010
also in the references at bottom i saw ;
12. A single positive marrow in multiple transmission attempts from cattle orally dosed with BSE-infected brain [Wells et al., 1999; Wells et al., 2005; Sohn et al., 2009].
Thursday, December 8, 2011
S. Korea confirms second case of iatrogenic Creutzfeldt-Jakob disease 48-year-old man 2011/12/08 11:08 KST
Thursday, December 08, 2011
A case of Iatrogenic Creutzfeldt Jakob Disease (iCJD) in a patient who had received a German-manufactured human dura mater graft 23 years ago
and just what about the potential for Alzheimers and other neurological diseases being transmissible i.e. iatrogenic ???
http://transmissiblespongiformencephalopathy.blogspot.com/2011/09/prionet-canada-researchers-in-vancouver.html http://betaamyloidcjd.blogspot.com/
Thursday, August 4, 2011
Terry Singeltary Sr. on the Creutzfeldt-Jakob Disease Public Health Crisis, Date aired: 27 Jun 2011
(SEE VIDEO)
U.S.A. 50 STATE BSE MAD COW CONFERENCE CALL Jan. 9, 2001
(tissue donor herds)
Saturday, December 3, 2011
Candidate Cell Substrates, Vaccine Production, and Transmissible Spongiform Encephalopathies Volume 17, Number 12—December 2011
Thursday, March 19, 2009
Chronic Wasting Disease Prions in Elk Antler Velvet (Nutritional Supplements and CJD)
LET US look at some history of science and debate there from of the potential/likelihood of TSE prion transmission via the dental route, some of the SEAC links no longer work.
SEAC
Spongiform Encephalopathy Advisory Committee
SEAC REVIEW ;
Saturday, February 27, 2010 SEAC Agenda 104th meeting on Friday 5th March 2010
Thursday, August 12, 2010
SEAC August 2010 Drayton Farm report update and more
Saturday, December 12, 2009
103RD MEETING OF THE SPONGIFORM ENCEPHALOPATHY ADVISORY COMMITTEE
Thursday, February 26, 2009
SEAC 102nd Meeting on Wednesday 4 March 2009 (SEE DH risk assessment on sourcing and pooling plasma)
Thursday, January 31, 2008
SPONGIFORM ENCEPHALOPATHY ADVISORY COMMITTEE Draft minutes of the 99th meeting held on 14th December 2007
snip...
ITEM 8 – PUBLIC QUESTION AND ANSWER SESSION
40. The Chair explained that the purpose of the question and answer session was to give members of the public an opportunity to ask questions related to the work of SEAC. Mr Terry Singeltary (Texas, USA) had submitted a question prior to the meeting, asking: “With the Nor-98 now documented in five different states so far in the USA in 2007, and with the two atypical BSE H-base
13 © SEAC 2007
cases in Texas and Alabama, with both scrapie and chronic wasting disease (CWD) running rampant in the USA, is there any concern from SEAC with the rise of sporadic CJD in the USA from ''unknown phenotype'', and what concerns if any, in relations to blood donations, surgery, optical, and dental treatment, do you have with these unknown atypical phenotypes in both humans and animals in the USA? Does it concern SEAC, or is it of no concern to SEAC? Should it concern USA animal and human health officials?”
41. A member considered that this question ............
Thursday, October 23, 2008 ONE HUNDRED AND FIRST MEETING OF THE SPONGIFORM ENCEPHALOPATHY ADVISORY COMMITTEE
Subject:
CJD: update for dental staff
Date: November 12, 2006 at 3:25 pm PST
1: Dent Update. 2006 Oct;33(8):454-6, 458-60.
CJD: update for dental staff.
Scully C, Smith AJ, Bagg J. Eastman Dental Institute, University of London.
It is almost a decade since the recognition of the emergence of a new infectious disease termed variant Creutzfeldt-Jakob disease (vCJD) caused by prions (PrPTSE), abnormal variants of a normal human cell surface protein (PrP).This disease has a number of similarities to other forms of CJD--lethal disorders characterized by a prolonged incubation period, and progressive mental deterioration. In relation to oral tissues, PrPTSE have been found in neural, gingival, pulpal, lingual, lymphoreticular and salivary gland tissue in animal models. In both sporadic and variant CJD, PrPTSE is detectable in the trigeminal ganglion and, in vCJD, in lymphoreticular tissues, but infectivity has not been tested in other human oral tissues. CLINICAL RELEVANCE: PrPTSE is much more resistant to the common methods of inactivation than conventional pathogens, and it adheres avidly to steel whilst retaining its infectivity. Particular attention must be paid to cleaning and sterilizing re-usable dental instruments. Single-use devices, such as endodontic files and matrix bands, must never be re-used. Advice on the reprocessing of dental instruments used on known CJD patients must be obtained from local infection control teams. Research into effective methods of prion inactivation appears promising, although further work on the applicability to general dental practice is required.
PMID: 17087448 [PubMed - in process]
Subject: PrPSc in salivary glands of scrapie-affected sheep
Date: February 15, 2007 at 9:33 am PST
J. Virol. doi:10.1128/JVI.02148-06 Copyright (c) 2007, American Society for Microbiology and/or the Listed Authors/Institutions. All Rights Reserved.
PrPSc in salivary glands of scrapie-affected sheep
Marta Vascellari*, Romolo Nonno, Franco Mutinelli, Michela Bigolaro, Michele Angelo Di Bari, Erica Melchiotti, Stefano Marcon, Claudia D'Agostino, Gabriele Vaccari, Michela Conte, Luigi De Grossi, Francesca Rosone, Francesco Giordani, and Umberto Agrimi Istituto Zooprofilattico Sperimentale delle Venezie, Histopathology Department, Viale dell'Università 10, 35020 Legnaro (PD), Italy; Istituto Superiore di Sanità , Department of Food Safety and Animal Health, Viale Regina Elena 299, 00161 Roma, Italy; Istituto Zooprofilattico Sperimentale delle Regioni Lazio e Toscana, Strada Terme, 01100 Viterbo, Italy
* To whom correspondence should be addressed. Email: mvascellari@izsvenezie.it .
Abstract
The salivary glands of scrapie-affected sheep and healthy controls were investigated for the presence of the pathological prion protein (PrPSc). PrPSc was detected in major (parotid and mandibular) and minor (buccal, labial and palatine) salivary glands of naturally and experimentally infected sheep. By western blot, PrPSc concentration in glands was estimated as 0.02-0.005% of brain. Immunohistochemistry revealed intracellular deposition of PrPSc in ductal and acinar epithelium and occasional labeling into the lumen of salivary ducts. The presence of PrPSc in salivary glands highlights the possible role of saliva in the horizontal transmission of scrapie.
SEAC 99th meeting on Friday 14th December 2007
snip...
© SEAC 2007
New research
4. Preliminary, unpublished results of research from the Health Protection Agency, aimed at addressing some of the uncertainties in the risk assessments, were reviewed by SEAC (SEAC 97, May 2007). The prion agent used in these studies is closely related to the vCJD agent. This research, using a mouse model, shows that following inoculation of mouse-adapted bovine spongiform encephalopathy (BSE) directly into the gut, infectivity subsequently becomes widespread in tissues of the oral cavity, including dental pulp, salivary glands and gingiva, during the preclinical as well as clinical stage of disease.
5. It is not known how closely the level and distribution of infectivity in the oral cavity of infected mice reflects those of humans infected with vCJD, as there are no comparable data from oral tissues, in particular dental pulp and gingiva, from human subclinical or clinical vCJD cases. Although no abnormal prion protein was found in a study of human dental tissues, including dental pulp, salivary glands and gingiva from vCJD cases22, the relationship between levels of infectivity and abnormal prion protein is unclear23. Infectivity studies underway using the mouse model and oral tissues that are presently available from human vCJD cases will provide some comparable data. On the basis of what is currently known, there is no reason to suppose that the mouse is not a good model for humans in respect to the distribution of infectivity in oral tissues. Furthermore, the new data are consistent with published results from experiments using a hamster scrapie model24.
6. A second set of experiments using the same mouse model showed that non-invasive and transient contact between gingival tissue and fine dental files contaminated with mouse-adapted BSE brain homogenate transmits infection very efficiently. It is not known how efficient gingival transmission would be if dental files were contaminated with infectious oral tissues and then subsequently cleaned and sterilised, a situation which would more closely model human dental practice. Further studies using the mouse model that would be more representative of the human situation, comparing oral tissues with a range of doses of infectivity, cleaned and sterilised files and the kind of tissue contact with instruments that occurs during dentistry, should be considered.
7. SEAC considered that the experiments appear well designed and the conclusions justified and reliable, while recognising that the research is incomplete and confirmatory experiments have yet to be completed. It is recommended that the research be completed, submitted for peer-review and widely disseminated as soon as possible so others can consider the implications. Nevertheless, these preliminary data increase the possibility that some oral tissues of humans infected with vCJD may potentially become infective during the preclinical stage of the disease. In addition, they increase the possibility that infection could potentially be transmitted not only via accidental abrasion of the lingual tonsil or endodontic procedures but a variety of routine dental procedures.
20 Department of Health (2006) Dentistry and vCJD: the implications of a carrier-state for a self-sustaining epidemic. Unpublished. 21 SEAC (2006) Position statement on vCJD and endodontic dentistry.
22 Head et al. (2003) Investigation of PrPres in dental tissues in variant CJD. Br. Dent. J. 195, 339-343. 23 SEAC 90 reserved business minutes.
Implications for transmission risks
snip...PLEASE SEE DISTURBING FINDINGS FULL TEXT HERE ;
A RE-ASSESSMENT OF THE POTENTIAL RISK OF VCJD TRANSMISSION VIA DENTISTRY ISSUE
1. The Department of Health (DH) has asked SEAC to consider an interim assessment of the potential risk of vCJD transmission via dental procedures. This work builds on previous risk assessments on possible dental transmission considered by SEAC.
BACKGROUND
Previous SEAC considerations of vCJD transmission via dentistry
snip...
The New DH Risk Assessment
8. The research on infectivity just noted forms one strand of a wider programme at the HPA, which is also intended to quantify protein residues found on dental instruments and the effectiveness of sterilisation in reducing infectivity. Following SEAC 97 (May 2007), DH commissioned a comprehensive re-assessment of the potential risks of vCJD transmission associated with dentistry to take account of research at the HPA and elsewhere. The assessment aims to clarify the range of plausible scenarios for vCJD transmission via dental instruments that could occur, given what is currently known, and to identify the most important factors affecting this risk. The assessment will be used to identify the most important areas of further work to address the uncertainties and any robust ways of cost effectively reducing risks further.
9. This new interim risk assessment has been produced by DH analysts (annex 3) in collaboration with a Scientific Reference Group of independent experts (Chaired by Professor Graham Medley). Members of the Group have expertise in dentistry, instrument decontamination, human and animal prion diseases, anatomy, public health, risk assessment modelling and epidemiology. This group met three times to review and refine the modelling framework and agree the risk assessment. The group provided advice on the inputs and assumptions incorporated into the risk assessment, particularly where expert judgement was required due to a lack of hard data. Under circumstances where key data are absent, precautionary assumptions were agreed. As a number of large uncertainties that strongly influence the quantification of risk remain, the risk assessment is considered as interim and will be updated in the future when new scientific evidence becomes available.
10. The assessment examines the risk that vCJD may be transmitted via dental procedures by establishing plausible ranges for key parameters, including (see sections 2 and 3 of the risk assessment):
• the vCJD infectivity of tissues of the oral cavity of infected patients
• the deposition of that material onto different types of dental instruments and the effectiveness of standard cleaning and sterilisation processes used in dental practice
• the mechanisms and efficiency of transfer of vCJD infectivity from contaminated instruments used on subsequent patients
• the probability of transmission based on assessments of the number and types of dental procedure conducted and the number of people who might be carrying an asymptomatic vCJD infection.
Findings 11.
As there is lack of substantial data with which to accurately quantify many of these parameters, plausible ranges for these parameters have been established to take account of the often large uncertainties in the data. The large uncertainties in many of these parameters strongly influence the quantification of the risk.
12. Plausible scenarios built up using ranges for each of these factors include many in which dental transmission would have no detectable effect on the course of the vCJD outbreak (see section 4 of the risk assessment). However, there are some which include a combination of pessimistic assumptions as regards the infectivity of dental / oral tissues and the effects of instrument decontamination which suggest that:
• there could be some hundreds of vCJD transmissions per annum via dentistry - albeit against a background of several thousand existing vCJD infections (not clinical cases of vCJD), or where
• dental transmission could generate a self-sustaining reservoir of vCJD infection within the population.
13. The distinction between vCJD infections and clinical cases of vCJD is important. If a large proportion of secondary transmissions result in subclinical infections (either never developing into clinical disease or doing so over an extended time-scale) and those infected are infectious, the likelihood of a self-sustaining epidemic increases. The proportion of individuals who might enter such a subclinical “carrier state” is unknown. Key Assumptions and areas of uncertainty
14. Work on the risk assessment is on-going and new data should enable some of the inputs and assumptions underpinning these scenarios to be revised. Key areas of uncertainty are:
• Infectivity in relevant tissues. Of all the unknowns, that of overriding importance is whether dental/oral tissues in patients incubating vCJD would be infective, and if so at what level.
There are as yet no results of studies using human gingival and dental pulp tissues, and these studies may extend into 2009 and 2010 respectively. This is examined in section 2.3 of the risk assessment.
• Protein Residues on dental instruments. This is examined in section 2.2 of the risk assessment.
• Efficacy of Autoclaving. This is examined in section 2.3 of the risk assessment.
• Current prevalence of vCJD infection. This is examined in section 3.3 of the risk assessment.
• Epidemiology of vCJD. This is examined in section 4 of the risk assessment.
15. Suggested areas of further work to reduce the uncertainty in these key areas are described in section 5 of the risk assessment together with a preliminary analysis of possible interventions and risk reduction measures.
ADVICE SOUGHT FROM THE COMMITTEE
snip...
POSITION STATEMENT vCJD AND ENDODONTIC DENTISTRY
snip...
Endodontic instruments
5. Evidence suggests that the files and reamers used in endodontic procedures are reused and are difficult to reliably decontaminate4. Appreciable quantities of residual material remain adherent to the surface after normal cleaning and sterilisation5. Thus, there is potential for transfer of dental pulp between patients undergoing endodontic procedures.
vCJD infectivity in dental tissues
6. There are no data on vCJD infectivity in dental pulp. Although no abnormal prions were found in a study of dental tissues, including dental pulp, from vCJD cases6, dental pulp includes blood and peripheral nerve tissue known to carry vCJD infectivity7,8. In addition, appreciable infectivity has been found in the dental pulp of hamsters with hamster scrapie9. Although it is possible that the peripheral nerve may only become infective close to, or after, the onset of clinical vCJD, inflammation may promote the propagation of prions10. Thus, although the data are limited and indirect, it is reasonable to assume that the dental pulp of individuals subclinically-infected with vCJD may be infectious although the level of infectivity is unknown. Studies underway will provide direct data on the infectivity in dental tissues from vCJD cases. level of infectivity is unknown.
4 Letters et al. (2005) A study of visual and blood contamination on reprocessed endodontic files from general dental practice. Br. Dent. J. 199, 522-525. 5 Smith et al. (2005) Residual protein levels on reprocessed dental instruments. J. Hosp. Infect. 61, 237-241. 6 Head et al. (2003) Investigation of PrPres in dental tissues in variant CJD. Br. Dent. J. 195, 339-343. 7 SEAC 91 minutes paragraph 9.
www.seac.gov.uk/papers/papers.htm 8
Department of Health (2005) Assessing the risk of vCJD transmission via surgery: an interim view. Unpublished. 9 Ingrosso et al. (1999) Transmission of the 263K scrapie strain by the dental route. J. Gen. Virol. 80, 3043-3047. 10 Heikenwalder et al. (2005) Chronic lymphocytic inflammation specifies the organ tropism of prions. Science. 307, 1107-1110.
Subclinical carrier state
7. A study of humanised mice showed that vCJD infections may not always progress to clinical disease within the normal lifespan of the animals11. Another study suggested that prion infections in mice that remain at a subclinical level can be transmitted to other mice, resulting in clinical disease12. Thus, there is evidence to suggest that individuals infected with the BSE / vCJD agent may remain in a subclinical infection carrier state instead of developing vCJD. A discrepancy between prevalence estimates based on a survey of abnormal prion protein in appendix and tonsil tissue and data on vCJD cases supports this hypothesis13. As no diagnostic test exists to identify such individuals, they could over the course of their lives be potential sources of numerous secondary infections arising from invasive medical or dental procedures.
8. The prevalence of subclinical infection in the UK population is uncertain. A recent estimate suggests the number of subclinical carriers may be of the order of several thousand14. SEAC has strongly recommended that further studies to ascertain better the prevalence of vCJD infection be urgently considered15.
Transmission risks
9. The new DH analysis suggests that, on the basis that residual dental pulp on endodontic files and reamers is transferred relatively efficiently to patients on reuse, dental pulp is as infective as peripheral nerve tissue and a subclinical carrier population for vCJD exists, a self-sustaining vCJD epidemic arising from endodontic surgery is plausible. There are uncertainties about the efficiency of vCJD transmission via endodontic procedures, the vCJD infectivity of dental pulp and the existence of a subclinical infection carrier state. However, even if a self-sustaining epidemic were not possible, clusters of vCJD infections could arise from the use of instruments contaminated with the vCJD agent from endodontic procedures on infected patients. Interactions between this and other routes of secondary transmission, such as blood transfusion and hospital surgery, would make a self-sustaining epidemic more likely.
Potential risk reduction measures
10. Endodontic files and reamers have a limited lifespan, restricting the number of possible secondary transmissions. Improving the effectiveness of procedures used to decontaminate dental instruments would reduce the risk of transmission. Restricting endodontic files and reamers to single use would prevent potential secondary transmission via these instruments. Conclusions
11. A preliminary risk assessment produced by DH suggests that vCJD transmission via endodontic dentistry may, under certain hypothetical but plausible scenarios, be sufficient to sustain a secondary vCJD epidemic. However, there are uncertainties around the data and assumptions underpinning the assessment. Research underway will address some of these uncertainties and allow the risk assessment to be refined. Once the research is complete and / or other data become available, the risks should be reassessed. A watching brief should be maintained.
12. It is unclear whether or not vCJD infectivity can be transmitted via endodontic files and reamers. However, given the plausibility of such a scenario and the large number of procedures undertaken annually, it would be prudent to consider restricting these instruments to single use as a precautionary measure. Since sufficiently rigorous decontamination of these instruments is difficult, single use of these instruments would eliminate this risk, should it exist.
SEAC May 2006
===================================
© SEAC 2007
New research
4. Preliminary, unpublished results of research from the Health Protection Agency, aimed at addressing some of the uncertainties in the risk assessments, were reviewed by SEAC (SEAC 97, May 2007). The prion agent used in these studies is closely related to the vCJD agent. This research, using a mouse model, shows that following inoculation of mouse-adapted bovine spongiform encephalopathy (BSE) directly into the gut, infectivity subsequently becomes widespread in tissues of the oral cavity, including dental pulp, salivary glands and gingiva, during the preclinical as well as clinical stage of disease.
5. It is not known how closely the level and distribution of infectivity in the oral cavity of infected mice reflects those of humans infected with vCJD, as there are no comparable data from oral tissues, in particular dental pulp and gingiva, from human subclinical or clinical vCJD cases. Although no abnormal prion protein was found in a study of human dental tissues, including dental pulp, salivary glands and gingiva from vCJD cases22, the relationship between levels of infectivity and abnormal prion protein is unclear23. Infectivity studies underway using the mouse model and oral tissues that are presently available from human vCJD cases will provide some comparable data. On the basis of what is currently known, there is no reason to suppose that the mouse is not a good model for humans in respect to the distribution of infectivity in oral tissues. Furthermore, the new data are consistent with published results from experiments using a hamster scrapie model24.
6. A second set of experiments using the same mouse model showed that non-invasive and transient contact between gingival tissue and fine dental files contaminated with mouse-adapted BSE brain homogenate transmits infection very efficiently. It is not known how efficient gingival transmission would be if dental files were contaminated with infectious oral tissues and then subsequently cleaned and sterilised, a situation which would more closely model human dental practice. Further studies using the mouse model that would be more representative of the human situation, comparing oral tissues with a range of doses of infectivity, cleaned and sterilised files and the kind of tissue contact with instruments that occurs during dentistry, should be considered.
7. SEAC considered that the experiments appear well designed and the conclusions justified and reliable, while recognising that the research is incomplete and confirmatory experiments have yet to be completed. It is recommended that the research be completed, submitted for peer-review and widely disseminated as soon as possible so others can consider the implications. Nevertheless, these preliminary data increase the possibility that some oral tissues of humans infected with vCJD may potentially become infective during the preclinical stage of the disease. In addition, they increase the possibility that infection could potentially be transmitted not only via accidental abrasion of the lingual tonsil or endodontic procedures but a variety of routine dental procedures.
20 Department of Health (2006) Dentistry and vCJD: the implications of a carrier-state for a self-sustaining epidemic. Unpublished. 21 SEAC (2006) Position statement on vCJD and endodontic dentistry.
22 Head et al. (2003) Investigation of PrPres in dental tissues in variant CJD. Br. Dent. J. 195, 339-343. 23 SEAC 90 reserved business minutes.
Implications for transmission risks
snip...
11. The new research also suggests that dental procedures involving contact with other oral tissues, including gingiva, may also be capable of transmitting vCJD. In the absence of a detailed risk assessment examining the potential for transmission via all dental procedures, it is not possible to come to firm conclusions about the implications of these findings for transmission of vCJD. However, given the potential for transmission by this route serious consideration should be given to assessing the options for reducing transmission risks such as improving decontamination procedures and practice or the implementation of single use instruments.
12. The size of the potential risk from interactions between the dental and other routes of secondary transmission, such as blood transfusion and hospital surgery, to increase the likelihood of a self-sustaining epidemic is unclear.
13. It is likely to be difficult to distinguish clinical vCJD cases arising from dietary exposure to BSE from secondary transmissions via dental procedures, should they arise, as a large proportion of the population is likely both to have consumed contaminated meat and undergone dentistry. However, an analysis of dental procedures by patient age may provide an indication of the age group in which infections, if they occur, would be most likely to be observed. Should the incidence of clinical vCJD cases in this age group increase significantly, this may provide an indication that secondary transmission via dentistry is occurring. Investigation of the dental work for these cases may provide supporting data. There is no clear evidence, to date, based on surveillance or investigations of clinical vCJD cases, that any vCJD cases have been caused by dental procedures but this possibility cannot be excluded.
Conclusions
14. Preliminary research findings suggest that the potential risk of transmission of vCJD via dental procedures may be greater than previously anticipated. Although this research is incomplete, uses an animal model exposed to relatively high doses of infectivity, and there are no data from infectivity studies on human oral tissues, these findings suggest an increased possibility that vCJD may be relatively efficiently transmitted via a range of dental procedures. Ongoing infectivity studies using human oral tissues and the other studies suggested here will enable more precise assessment of the risks of vCJD transmission through dental procedures.
15. Guidance was issued to dentists earlier this year recommending that endodontic files and reamers be treated as single use which, provided it is adhered to, will remove any risk of a self-sustaining epidemic arising from re-use of these instruments. To minimise risk it is critical that appropriate management and audit is in place, both for NHS and private dentistry.
16. It is also critical that a detailed and comprehensive assessment of the risks of all dental procedures be conducted as a matter of urgency. While taking into account the continuing scientific uncertainties, this will allow a more thorough consideration of the possible public health implications of vCJD transmission via dentistry and the identification of possible additional precautionary risk reduction measures. The assessment will require continued updating as more evidence becomes available on the transmissibility of vCJD by dental routes, and on the prevalence of infection within the population. A DH proposal to convene an expert group that includes dental professionals to expedite such an assessment is welcomed. Given the potential for transmission via dentistry, consideration should be given to the urgent assessment of new decontamination technologies which, if proved robust and effective, could significantly reduce transmission risks.
SEAC June 2007
27 SEAC Epidemiology Subgroup (2006) position statement of the vCJD epidemic.
28 DH (2007) Precautionary advice given to dentists on re-use of instruments
see full text 17 pages ;
SEAC 99th meeting on Friday 14th December 2007
DECEMBER 14, 2007, 10 year Anniversary of my Moms death 'confirmed' from Heidenhain Variant Creutzfeldt Jakob Disease
Greetings,
AS one of them _lay_ folks, one must only ponder ;
"WITH the Nor-98 now documented in five different states so far in the USA in 2007, and with the TWO atypical BSE H-BASE cases in Texas and Alabama, with both scrapie and CWD running rampant in the USA, IS there any concern from SEAC with the rise of sporadic CJD in the USA from ''UNKNOWN PHENOTYPE'', and what concerns if any, in relations to blood donations, surgery, optical, and dental, do you have with these unknown atypical phenotypes in both humans and animals in the USA ???"
"Does it concern SEAC, or is it of no concern to SEAC?"
"Should it concern USA animal and human health officials?"
snip...
13 DH (2007) Precautionary advice given to dentists on re-use of instruments
-------- Original Message --------
Subject: 26th June 2003 - The 78th SEAC meeting took place on the 24th June
Date: Sun, 29 Jun 2003 09:30:36 –0500
From: "Terry S. Singeltary Sr." flounder@wt.net
Reply-To: Bovine Spongiform Encephalopathy BSE-L@uni-karlsruhe.de
To: BSE-L@uni-karlsruhe.de
######## Bovine Spongiform Encephalopathy #########
26th June 2003 - The 78th SEAC meeting took place on the 24th June, a summary <http://www.seac.gov.uk/summaries/summ_0603.htm> of that meeting is available. At this meeting the minutes from the 77th meeting in February were approved and are now available in the previous meetings <http://www.seac.gov.uk/papers/papers.htm> section of this website. Additionally available is an updated document (PDF) listing the commercial and non-commercial interests <http://www.seac.gov.uk/committee/interest.pdf>of the SEAC members...
Summary of the 78th SEAC meeting on 24th June 2003
------------------------------------------------------------------------
The Spongiform Encephalopathy Advisory Committee (SEAC) held its 78th meeting in London on 24 June 2003, when it discussed the following matters:
Risk Assessment on Ox Tongue and Associate Tonsil Tissue
At an earlier meeting SEAC considered a new finding of BSE infectivity in ox tongue. SEAC recommended that a risk assessment be conducted and this was commissioned by the Food Standards Agency, and presented at the June 2003 meeting. The risk assessment considered the possible range of human exposure to BSE infectivity from the consumption of ox tongue. The Committee concluded that it was not possible to advise the FSA precisely on the magnitude of the risk due to the substantial scientific uncertainty inherent in the risk assessment. However, the Committee agreed that the scientific evidence indicated that the potential risk of infectivity from eating tongue was likely to be very small. The Committee identified further scientific work that would help to refine the risk estimates.
Review of the use of MMBM in fertiliser
The Department of the environment, food and rural affairs (Defra) asked SEAC to provide scientific advice on the animal health implications of proposed changes to UK fertiliser controls. SEAC agreed that the proposed use of ash from the incineration of meat and bone meal (MBM) derived from category 2 and category 3 material without restriction on land would not result in significant additional risk to animal health. SEAC confirmed its earlier advice that mammalian MBM should not be permitted in fertilisers likely to be spread on agricultural land or land where animals may graze.
VLA Survey – Scrapie Surveillance in Sheep
The Committee noted the preliminary results of a report from the Veterinary Laboratories Agency estimating the prevalence of scrapie in the national flock. The Committee also noted that a full report would be available in due course, containing all of the data from the study.
vCJD Update
The National CJD surveillance unit reported that 136 vCJD cases have been confirmed in the UK with 4 cases still alive. All vCJD cases tested to date are of the same genotype (Methionine homozygous at codon 129 of the PrP gene). All vCJD cases so far identified in 2003 have reported the onset of clinical signs in 2002. Therefore the total number of onsets in 2002 cannot yet be confirmed.
Report from the SEAC Epidemiology sub-group
The Chairman of this specialist sub-group reported to SEAC that there continues to be statistical evidence that the vCJD epidemic is no longer increasing at the rate seen previously and that the underlying incidence may have reached or be reaching a peak. However the possibility of susceptible genotypes other than methionine homozygotes and the theoretical possibility of other clinical manifestations of infection with the BSE agent other than vCJD means that prediction of the evolution of the epidemic is uncertain and continued surveillance is essential.
Expert Group on Strain Differentiation
SEAC received a report from the Chairman of an expert group of the EU Community TSE Reference Laboratory Committee, which met on 23 June 2003 to review progress on a trial to evaluate rapid TSE tests.
Quinquennial Review of SEAC
The Committee welcomed the recommendations outlined in the SEAC Quinquennial Review Report published in March 2003...END...TSS
12-31-2007, 01:09 PM
Risk Assessment of Transmission of Sporadic Creutzfeldt-Jakob Disease in Endodontic Practice in Absence of Adequate Prion Inactivation
Nadège Bourvis1,2, Pierre-Yves Boelle1,2,3, Jean-Yves Cesbron4,5,6, Alain-Jacques Valleron1,2,3*
1 Université Pierre et Marie Curie-Paris6, Unité de Recherche Epidémiologie-Systèmes d'information-Modélisation, UMR S 707, Paris, France, 2 INSERM, U707, Paris, France, 3 Assistance Publique-Hôpitaux de Paris (AP-HP), Unité de Santé Publique, Hôpital St Antoine, Paris, France, 4 Laboratoire Adaptation et de Pathogénie des Micro-organismes, Université Joseph Fourier, UMR 5163, Grenoble, France, 5 Centre National de la Recherche Scientifique (CNRS), UMR 5163, Grenoble, France, 6 Centre hospitalier universitaire (CHU) de Grenoble, Laboratoire d'Immunologie, Grenoble, France
Abstract
Background
Experimental results evidenced the infectious potential of the dental pulp of animals infected with transmissible spongiform encephalopathies (TSE). This route of iatrogenic transmission of sporadic Creutzfeldt-Jakob disease (sCJD) may exist in humans via reused endodontic instruments if inadequate prion decontamination procedures are used.
Methodology/Principal Findings
To assess this risk, 10 critical parameters in the transmission process were identified, starting with contamination of an endodontic file during treatment of an infectious sCJD patient and ending with possible infection of a subsequent susceptible patient. It was assumed that a dose-risk response existed, with no-risk below threshold values. Plausible ranges of those parameters were obtained through literature search and expert opinions, and a sensitivity analysis was conducted. Without effective prion-deactivation procedures, the risk of being infected during endodontic treatment ranged between 3.4 and 13 per million procedures. The probability that more than one case was infected secondary to endodontic treatment of an infected sCJD patient ranged from 47% to 77% depending on the assumed quantity of infective material necessary for disease transmission. If current official recommendations on endodontic instrument decontamination were strictly followed, the risk of secondary infection would become quasi-null.
Conclusion
The risk of sCJD transmission through endodontic procedure compares with other health care risks of current concern such as death after liver biopsy or during general anaesthesia. These results show that single instrument use or adequate prion-decontamination procedures like those recently implemented in dental practice must be rigorously enforced.
Citation: Bourvis N, Boelle P-Y, Cesbron J-Y, Valleron A-J (2007) Risk Assessment of Transmission of Sporadic Creutzfeldt-Jakob Disease in Endodontic Practice in Absence of Adequate Prion Inactivation. PLoS ONE 2(12): e1330. doi:10.1371/journal.pone.0001330
Academic Editor: Alison Galvani, Yale University, United States of America
Received: April 30, 2007; Accepted: November 26, 2007; Published: December 26, 2007
Copyright: © 2007 Bourvis 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: EU contract INFTRANS
Competing interests: The authors have declared that no competing interests exist.
* To whom correspondence should be addressed. E-mail: alain-jacques.valleron@upmc.fr
snip...
Discussion
The results of this modelling approach show that the risk of sCJD transmission due to the reuse of instruments during ET may not be ignored in absence of effective prion-decontamination procedures.
How should our conclusions be used in a public health assessment? First note that this risk is already of concern to national health agencies as well as to health professionals [25]–[27]. Our work makes it possible to go beyond a qualitative assessment, towards more quantitative predictions where all hypotheses are clearly stated. The conclusions of this approach may easily be updated as new data accrue.
The details of ET were obtained from the latest official reports in France and UK or from experts. We conducted a literature search to collect the best estimates available of the possible quantities of infectious material left on the instruments, and subsequently partially removed by the classical disinfection procedures used until the last years of the 20th century. We obtained similarly estimates of the values of brain infectivity and of the ratio of brain infectivity to pulp infectivity. These parameters were obtained from animal experiments as they are clearly unknown in humans.
A comparable approach can be found in the HPA report on vCJD transmission in dentistry with two notable differences [25]. First, the route of instrument contamination and subsequent transmission considered in the HPA report was a very rare accidental process: the abrasion of tonsillar tissue during dental care. On the contrary, we considered the process of accessing the dental pulp during ET as certain, which obviously leads to a higher risk. Second, the HPA report considered infectivity of tonsils to be 106–107 i/c ID50 per gram, while we used dental pulp with a slightly lower range of infectivity from 104-106i/c ID50 per gram ( = BI* BPR).
The hypotheses we used concerning the relationship between the estimated inoculums and the probability of infection are obviously critical. In our assessment, we postulated that too small an inoculum (below 10−1 and 10−2 ID50 were considered with functions Ï•1 and Ï•2) would not lead to infection, and that there was a linear dose–response relationship above this threshold. This effectively complies with the “zero risk below a threshold” hypothesis rather than with the “single infectious particle” hypothesis. There is indeed experimental evidence that even very small quantities of infectious material may trigger infection in mice [13], [28], and this hypothesis was previously used in assessing decontamination procedures[29]. However, we adopted a more conservative risk estimate.
The duration of the infectious period of CJD is unknown but could be very long. We used as a reference the incubation period estimated from hGH iatrogenic cases [30]. To make comparison easier, and for want of better or more recent evidence, the duration of the infectious period relative to incubation was the same as in the HPA report, i.e. 40% of the incubation period [25].
Our risk assessment should have used the prevalence of infectious sCJD in those undergoing ET instead of that in the general population. Presumably, the former is the largest and the risk was therefore minimized. Indeed, children, who do not develop sCJD are taken into account in the general population estimate, when that in ET patients concerns only adults.
The ranges of values of risk assessment generated with our model were broad. They mirror the current lack of knowledge and the uncertainties concerning data and hypotheses. However, our model makes it clear that the ET of the 20th century were not risk-free in terms of CJD. Therefore, our model suggests that patients may well have been contaminated at the end of 20th century, and still be in the latency period and at risk of transmitting the disease.
The estimated individual risk of sCJD transmission during ET was low in our assessment. However, these values compared with the mortality rates in general anaesthesia [31], transcutaneous liver biopsy [32] or voluntary abortion [33] which are of concern in the modern health care.
We also studied the possible impact of ET at a population level and showed that there was a high probability that the reproduction rate R exceeded 1 in the absence of effective prion decontamination of the instruments: one of the conditions for the initiation of an epidemic process is fulfilled. To date, epidemiological surveillance data did not evidence such an epidemic process. However, would our hypothesis be true, the increase in incidence could remain modest and hard to identify for dozens of years because the incidence of sCJD is low, the incubation period long and in competition with all mortality causes present. CJD surveillance systems is too recent to show such trends.
Vacuum autoclaving and porous-load autoclaving for 18 min at 134°C are currently recognised as appropriate methods for prion decontamination, leading to a reduction of the infectivity load by of 3–5 log10 or more. According to our model, this decontamination would prevent CJD transmission in dental practice, even considering that the residual infectivity is not strictly reduced to zero. These methods are recommended in official reports in various countries. However, in a US study conducted in 1996 [34], only 53% of dentists used autoclaves to decontaminate root-canal files. In a survey conducted in France in 2004, only 79% of dentists used an autoclave [35]. The problem of correct use of the autoclaves and regular checking of their efficacy has also been raised by many authors in several countries [34]. A recent survey on dental practice also showed that other elementary precautionary measures against CJD transmission were not widely respected. For example, the vast majority of dentists did not actively seek out patients at-risk for any form of CJD (sporadic, iatrogenic or familial) [36]. Therefore, in the current situation and despite recommended decontamination procedures, the risk of sCJD transmission during dental care might still not be zero. In any case, our findings constitute a strong argument for the strict respect of the official recommendations on decontamination procedures in dentistry, and even suggest that the cost-benefit of single-use endodontic instruments should be re-evaluated.
The risk analysis approach we have used relies on a “problem dissection” in which all components to a risk are identified and linked to the available scientific data, knowledge, and expert opinion. It may be of help in other emerging diseases, when data on the natural history of the disease and transmission are still scarce and clinical events cannot be observed directly. In all these cases, the output of the work will always be questionable, because of the lack of data, but the strength of the method is that its results and final statements are refutable as data accrues.
snip... end... tss
Tuesday, August 12, 2008
Biosafety in Microbiological and Biomedical Laboratories Fifth Edition 2007 (occupational exposure to prion diseases)
Monday, August 17, 2009
Transmissible Spongiform Encephalopathy Agents: Safe Working and the Prevention of Infection: Annex J,K, AND D Published: 2009
Friday, July 17, 2009
Revision to pre-surgical assessment of risk for vCJD in neurosurgery and eye surgery units Volume 3 No 28; 17 July 2009
Published Date: 2010-03-04 16:00:03
Subject: PRO/AH/EDR> Prion disease update (03)
Archive Number: 20100304.0709
Tuesday, March 16, 2010
Transmissible Spongiform Encephalopathy Agents: Safe Working and the Prevention of Infection: Part 4 REVISED FEB. 2010
Tuesday, May 11, 2010
Current risk of iatrogenic Creutzfeld-Jakob disease in the UK: efficacy of available cleaning chemistries and reusability of neurosurgical instruments
Saturday, January 16, 2010
Evidence For CJD TSE Transmission Via Endoscopes 1-24-3 re-Singeltary to Bramble et al
Evidence For CJD/TSE Transmission Via Endoscopes
Tuesday, March 29, 2011
TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHY EXPOSURE SPREADING VIA HOSPITALS AND SURGICAL PROCEDURES AROUND THE GLOBE
Monday, May 16, 2011
Does Poor Dental Health Have a Role in the Emergence of Variant Creutzfeldt Jakob Disease in the United Kingdom?
Sunday, October 23, 2011
The oral secretion of infectious scrapie prions occurs in pre-clinical sheep with a range of PRNP genotypes
JVI Accepts, published online ahead of print on 19 October 2011
Wednesday, August 24, 2011
All Clinically-Relevant Blood Components Transmit Prion Disease following a Single Blood Transfusion: A Sheep Model of vCJD
http://transmissiblespongiformencephalopathy.blogspot.com/2011/08/all-clinically-relevant-blood.html
Wednesday, August 24, 2011
There Is No Safe Dose of Prions
Friday, December 16, 2011
Creutzfeldt-Jacob Disease Question Asked by Lord Walton of Detchant P-Capt filter
Sunday, December 18, 2011
A blood test for variant Creutzfeldt‐Jakob disease: briefing note for patients, carers and health professionals
Monday, September 26, 2011
L-BSE BASE prion and atypical sporadic CJD
Thursday, August 4, 2011
Terry Singeltary Sr. on the Creutzfeldt-Jakob Disease Public Health Crisis, Date aired: 27 Jun 2011
CANADA CJD UPDATE 2011
CJD Deaths Reported by CJDSS1, 1994-20112 As of January 31, 2011
3. Final classification of 49 cases from 2009, 2010, 2011 is pending.
snip...
USA 2011
USA
National Prion Disease Pathology Surveillance Center
Cases Examined1
(November 1, 2010)
Year Total Referrals2 Prion Disease Sporadic Familial Iatrogenic vCJD
1996 & earlier 51 33 28 5 0 0
1997 114 68 59 9 0 0
1998 87 51 43 7 1 0
1999 121 73 65 8 0 0
2000 146 103 89 14 0 0
2001 209 119 109 10 0 0
2002 248 149 125 22 2 0
2003 274 176 137 39 0 0
2004 325 186 164 21 0 13
2005 344 194 157 36 1 0
2006 383 197 166 29 0 24
2007 377 214 187 27 0 0
2008 394 231 205 25 0 0
2009 425 258 215 43 0 0
2010 333 213 158 33 0 0
TOTAL 38315 22656 1907 328 4 3
1 Listed based on the year of death or, if not available, on year of referral;
2 Cases with suspected prion disease for which brain tissue and/or blood (in familial cases) were submitted;
3 Disease acquired in the United Kingdom;
4 Disease was acquired in the United Kingdom in one case and in Saudi Arabia in the other case;
5 Includes 18 cases in which the diagnosis is pending, and 18 inconclusive cases;
6 Includes 23 (22 from 2010) cases with type determination pending in which the diagnosis of vCJD has been excluded.
Please notice where sporadic CJD cases in 1996 went from 28 cases, to 215 cases in 2009, the highest recorded year to date. sporadic CJD is on a steady rise, and has been since 1996.
I also urge you to again notice these disturbing factors in lines 5 and 6 ;
5 Includes 18 cases in which the diagnosis is pending, and 18 inconclusive cases;
6 Includes 23 (22 from 2010) cases with type determination pending in which the diagnosis of vCJD has been excluded.
========end=====tss=====2011
PPS POLITICAL PRION SCIENCE $$$
Creutzfeldt-Jakob Disease Surveillance in Texas
Sunday, July 11, 2010
CJD or prion disease 2 CASES McLennan County Texas population 230,213 both cases in their 40s
see the continuing rise of sporadic CJD in Texas here ;
Saturday, March 5, 2011
MAD COW ATYPICAL CJD PRION TSE CASES WITH CLASSIFICATIONS PENDING ON THE RISE IN NORTH AMERICA
Sunday, August 21, 2011
The British disease, or a disease gone global, The TSE Prion Disease
(see video here)
U.S.A. HIDING MAD COW DISEASE VICTIMS AS SPORADIC CJD ?
(see video at bottom)
Sunday, September 6, 2009
MAD COW USA 1997
(SEE SECRET VIDEO)
Tuesday, November 01, 2011
Could we face the return of CJD? Experts fear it may lie dormant in thousands
MAD COW DISEASE, TEXAS STYLE
Wednesday, June 15, 2011
Galveston, Texas - Isle port moves through thousands of heifers headed to Russia, none from Texas, Alabama, or Washington, due to BSE risk factor
Wednesday, March 31, 2010
Atypical BSE in Cattle
To date the OIE/WAHO assumes that the human and animal health standards set out in the BSE chapter for classical BSE (C-Type) applies to all forms of BSE which include the H-type and L-type atypical forms. This assumption is scientifically not completely justified and accumulating evidence suggests that this may in fact not be the case. Molecular characterization and the spatial distribution pattern of histopathologic lesions and immunohistochemistry (IHC) signals are used to identify and characterize atypical BSE. Both the L-type and H-type atypical cases display significant differences in the conformation and spatial accumulation of the disease associated prion protein (PrPSc) in brains of afflicted cattle. Transmission studies in bovine transgenic and wild type mouse models support that the atypical BSE types might be unique strains because they have different incubation times and lesion profiles when compared to C-type BSE. When L-type BSE was inoculated into ovine transgenic mice and Syrian hamster the resulting molecular fingerprint had changed, either in the first or a subsequent passage, from L-type into C-type BSE.
In addition, non-human primates are specifically susceptible for atypical BSE as demonstrated by an approximately 50% shortened incubation time for L-type BSE as compared to C-type. Considering the current scientific information available, it cannot be assumed that these different BSE types pose the same human health risks as C-type BSE or that these risks are mitigated by the same protective measures.
This study will contribute to a correct definition of specified risk material (SRM) in atypical BSE. The incumbent of this position will develop new and transfer existing, ultra-sensitive methods for the detection of atypical BSE in tissue of experimentally infected cattle.
Thursday, August 12, 2010
Seven main threats for the future linked to prions
First threat
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.
Second threat
snip...
Rural and Regional Affairs and Transport References Committee
The possible impacts and consequences for public health, trade and agriculture of the Government's decision to relax import restrictions on beef Final report June 2010
2.66 Dr Fahey also told the committee that in the last two years a link has been established between forms of atypical CJD and atypical BSE. Dr Fahey said that: They now believe that those atypical BSEs overseas are in fact causing sporadic Creutzfeldt-Jakob disease. They were not sure if it was due to mad sheep disease or a different form. If you look in the textbooks it looks like this is just arising by itself. But in my research I have a summary of a document which states that there has never been any proof that sporadic Creutzfeldt-Jakob disease has arisen de novo-has arisen of itself. There is no proof of that. The recent research is that in fact it is due to atypical forms of mad cow disease which have been found across Europe, have been found in America and have been found in Asia. These atypical forms of mad cow disease typically have even longer incubation periods than the classical mad cow disease.50
ANOTHER ATYPICAL CJD CASE (POTENTIALLY OCCUPATIONAL TIED TO BEEF INDUSTRY) IN TEXAS THAT WAS SWEPT UNDER THE RUG
CJD TEXAS 38 YEAR OLD FEMALE WORKED SLAUGHTERING CATTLE EXPOSED TO BRAIN AND SPINAL CORD MATTER
"Up until about 6 years ago, the pt worked at Tyson foods where she worked on the assembly line, slaughtering cattle and preparing them for packaging. She was exposed to brain and spinal cord matter when she would euthanize the cattle."
Irma Linda Andablo CJD Victim, she died at 38 years old on February 6, 2010 in Mesquite Texas
Irma Linda Andablo CJD Victim, she died at 38 years old on February 6, 2010 in Mesquite Texas.She left 6 Kids and a Husband.The Purpose of this web is to give information in Spanish to the Hispanic community, and to all the community who want's information about this terrible disease.-
Physician Discharge Summary, Parkland Hospital, Dallas Texas
Admit Date: 12/29/2009 Discharge Date: 1/20/2010 Attending Provider: Greenberg, Benjamin Morris; General Neurology Team: General Neurology Team
Linda was a Hispanic female with no past medical history presents with 14 months of incresing/progressive altered mental status, generalized weakness, inability to walk, loss of appetite, inability to speak, tremor and bowel/blader incontinence.She was, in her usual state of health up until February, 2009, when her husbans notes that she began forgetting things like names and short term memories. He also noticed mild/vague personality changes such as increased aggression. In March, she was involved in a hit and run MVA,although she was not injured. The police tracked her down and ticketed her. At that time, her son deployed to Iraq with the Army and her husband assumed her mentation changes were due to stress over these two events. Also in March, she began to have weakness in her legs, making it difficult to walk. Over the next few months, her mentation and personality changes worsened, getting to a point where she could no longer recognized her children. She was eating less and less. She was losing more weight. In the last 2-3 months, she reached the point where she could not walk without an assist, then 1 month ago, she stopped talking, only making grunting/aggressive sounds when anyone came near her. She also became both bowel and bladder incontinent, having to wear diapers. Her '"tremor'" and body jerks worsened and her hands assumed a sort of permanent grip position, leading her family to put tennis balls in her hands to protect her fingers.
The husband says that they have lived in Nebraska for the past 21 years. They had seen a doctor there during the summer time who prescribed her Seroquel and Lexapro, Thinking these were sx of a mood disorder. However, the medications did not help and she continued to deteriorate clinically. Up until about 6 years ago, the pt worked at Tyson foods where she worked on the assembly line, slaughtering cattle and preparing them for packaging. She was exposed to brain and spinal cord matter when she would euthanize the cattle. The husband says that he does not know any fellow workers with a similar illness. He also says that she did not have any preceeding illness or travel.
[Terry S. Singeltary Sr. has added the following comment:
"According to the World Health Organisation, the future public health threat of vCJD in the UK and Europe and potentially the rest of the world is of concern and currently unquantifiable. However, the possibility of a significant and geographically diverse vCJD epidemic occurring over the next few decades cannot be dismissed.
Terry S. Singeltary Sr. has added the following comment:
"According to the World Health Organisation, the future public health threat of vCJD in the UK and Europe and potentially the rest of the world is of concern and currently unquantifiable. However, the possibility of a significant and geographically diverse vCJD epidemic occurring over the next few decades cannot be dismissed.
The key word here is diverse. What does diverse mean? If USA scrapie transmitted to USA bovine does not produce pathology as the UK c-BSE, then why would CJD from there look like UK vCJD?"
When L-type BSE was inoculated into ovine transgenic mice and Syrian hamster the resulting molecular fingerprint had changed, either in the first or a subsequent passage, from L-type into C-type BSE. In addition, non-human primates are specifically susceptible for atypical BSE as demonstrated by an approximately 50% shortened incubation time for L-type BSE as compared to C-type. Considering the current scientific information available, it cannot be assumed that these different BSE types pose the same human health risks as C-type BSE or that these risks are mitigated by the same protective measures.
This study will contribute to a correct definition of specified risk material (SRM) in atypical BSE. The incumbent of this position will develop new and transfer existing, ultra-sensitive methods for the detection of atypical BSE in tissue of experimentally infected cattle.
The conclusions state that, at present, the only TSE agent demonstrated to be zoonotic is the classical BSE agent. Active screening has allowed the identification of 3 new forms of animal TSEs (H-type atypical BSE, L-type atypical BSE, and atypical scrapie), but the information obtained has major limitations due to the unknown sensitivity of the current monitoring system for these TSEs. There is no epidemiological evidence to suggest that classical scrapie is zoonotic. The epidemiological data are too limited to conclude whether the atypical scrapie agent has a zoonotic potential. Transmission experiments to human PrP transgenic mice or primates suggest that some TSE agents other than the classical BSE agent in cattle (namely L-type atypical BSE, classical BSE in sheep, TME, CWD agents) might have zoonotic potential and indicate that that of the L-type atypical BSE agent appears similar or even higher than that of the classical BSE agent. A single study reported efficient transmission of a natural sheep classical scrapie isolate to primates.
Commentary ---------- Following to a request from the European Commission, the Panel on Biological Hazards (BIOHAZ) and the European Centre for Disease Prevention and Control (ECDC) were asked to deliver a scientific opinion on any possible epidemiological or molecular association between transmissible spongiform encephalopathies (TSEs) in animals and humans. The opinion reviews and discusses the existing scientific evidence that links animal and human TSEs currently known.
The opinion first considers the definition of zoonoses and the principles for the identification of zoonotic diseases, which can be based on evidence gathered from both epidemiological and laboratory studies. The opinion describes the challenges involved in identifying TSEs as zoonoses, due to the specific characteristics of TSE infections/diseases, such as the nature of TSE agents, the occurrence of animal and human TSEs, and the type of monitoring applied, the long incubation period of TSEs etc. The example of the process that led to establishing a link between bovine spongiform encephalopathy (BSE) and variant Creutzfeldt-Jakob disease (vCJD) is reviewed. The epidemiological and laboratory criteria that can be used to investigate such a link are described in detail, since those criteria might be useful for the identification of links between other animal and human TSEs.
The opinion discusses the strain diversity of the TSE agents described in sheep, goats, cattle, cervids, and humans, based on the current knowledge, which highlights that multiple TSE agents exist in each species. The factors influencing the capacity of TSE agents to cross the species transmission barrier are then considered in detail, including the variability in host and donor PrP gene and protein, the TSE strain type involved and its interaction with the host PrP, and the route of infection.
The opinion critically assesses the tools and methodologies currently available to study and evaluate the possible association between animal and human TSEs. The use of epidemiology is discussed for TSEs in both animals and humans, and the possibility to compare the 2 sources of information is presented as a possible method to study the possible links.
Both in vivo and in vitro laboratory methods are considered and discussed, including neuropathology, transmission experiments involving different animal models (wild type and transgenic mice, primates and other species), biochemical methods, cell-free conversion assays, protein misfolding cyclic amplification (PMCA), and cell culture assays. Characteristics, advantages, and disadvantages of the different methods are reviewed, including the opportunity to collate data from different types of experiments for the study of potential associations between animal and human TSEs.
The opinion then reviews the scientific evidence currently available for the different animal and human TSEs, including classical BSE, atypical BSE (H-type and L-type), classical scrapie, atypical scrapie, chronic wasting disease (CWD), transmissible mink encephalopathy (TME), and human TSEs. In particular, the following aspects are systematically discussed for each TSE agent: epidemiology, pathogenesis, and in vivo and in vitro transmission experiments.
The opinion concludes that, at present, the only TSE agent demonstrated to be zoonotic is the classical BSE agent. With regard to human TSEs, detected cases of sporadic CJD are randomly distributed in time and geographical location. These observations have been interpreted as a supportive argument that sporadic CJD is not environmentally acquired. However, the epidemiological evidence in relation to sporadic CJD cannot be regarded as definitive, and the possibility that a small proportion of cases are zoonotic cannot be excluded.
It also concludes that a series of uncertainties in relation to the epidemiological patterns of animal and human TSEs indicate that even a rough comparison of the present epidemiological patterns of human and animal TSEs other than classical BSE is unlikely to be informative. Because of these uncertainties, it is an imperative to continue to carry out systematic surveillance of human TSE diseases, and to continue and improve the surveillance of animal TSE diseases.
The opinion highlights that the active screening has allowed the identification of 3 new forms of animal TSEs (L-type atypical BSE, H-type atypical BSE, and atypical scrapie), but that the information obtained has major limitations due to the unknown sensitivity of the current monitoring system for these TSEs.
There is no epidemiological evidence to suggest that classical scrapie is zoonotic. The epidemiological data are too limited to conclude whether the atypical scrapie agent has a zoonotic potential.
Transmission experiments to human PrP transgenic mice suggest that some TSE agents other than the classical BSE agent in cattle (namely L-type atypical BSE and classical BSE in sheep agents) might have zoonotic potential, whereas for other agents there is no evidence provided of a zoonotic potential (H-type atypical BSE and CWD), or no published studies are available (classical and atypical scrapie). In addition, transmission experiments to primates suggest that some TSE agents other than the classical BSE agent in cattle (namely L-type atypical BSE, classical BSE in sheep, TME, CWD agents) might have zoonotic potential. In particular, primates are highly permissive to L-type atypical BSE, even by the oral route.
The opinion emphasizes that laboratory transmission experiments indicate that the L-type atypical BSE agent has a significant zoonotic potential, which appears similar or even higher than that of the classical BSE agent. While transmission data for evaluating the zoonotic potential of classical scrapie in primates and human PrP transgenic mice are extremely limited or not yet available, a single study reported efficient transmission of a natural sheep classical scrapie isolate to primates.
The opinion concludes that human PrP transgenic mice and primates are currently the most relevant models for investigating the human transmission barrier, but the extent to which such models are informative for measuring the zoonotic potential of an animal TSE under field exposure conditions is unknown. It is unpredictable whether a TSE agent will transmit to a new host, and if the transmission principally occurs, what the transmission rate will be.
Based on the results obtained with in vitro conversion assays, the opinion concludes that there is probably no absolute molecular barrier to transmission of TSE agents between mammalian species. Results also suggest that these assays may be developed as a tool for quantifying the transmission barriers between species for different TSE agent strains; however, there is no means at the moment to transpose in vitro results into the likelihood of in vivo interspecies transmission.
-- Communicated by: Terry S Singeltary Sr
[ProMED-mail thanks Terry S Singeltary Sr for drawing attention to this comprehensive document which provides a current evaluation of experimental work designed to explore the zoonotic potential of the various recently recognised TSEs of domestic and other animals.
It is concluded that at present the only TSE agent demonstrated to be zoonotic is the classical BSE agent. Nor can it be entirely excluded at the present time that a small proportion of cases of sporadic CJD may be environmentally acquired. - Mod.CP]
******
2011
EFSA Journal 2011 The European Response to BSE: A Success Story
This is an interesting editorial about the Mad Cow Disease debacle, and it's ramifications that will continue to play out for decades to come ;
Monday, October 10, 2011
EFSA Journal 2011 The European Response to BSE: A Success Story
snip...
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.
snip...
see follow-up here about North America BSE Mad Cow TSE prion risk factors, and the ever emerging strains of Transmissible Spongiform Encephalopathy in many species here in the USA, including humans ;
Monday, November 14, 2011
WYOMING Creutzfeldt Jakob Disease, CWD, TSE, PRION REPORTING 2011
Wednesday, November 16, 2011
Wisconsin Creutzfeldt Jakob Disease, CWD, TSE, PRION REPORTING 2011
Sunday, November 13, 2011
COLORADO CWD CJD TSE PRION REPORTING 2011
MARCH 1, 2011
UPDATED CORRESPONDENCE FROM AUTHORS OF THIS STUDY I.E. COLBY, PRUSINER ET AL, ABOUT MY CONCERNS OF THE DISCREPANCY BETWEEN THEIR FIGURES AND MY FIGURES OF THE STUDIES ON CWD TRANSMISSION TO CATTLE ;
----- Original Message -----
From: David Colby
To: flounder9@verizon.net
Cc: stanley@XXXXXXXX
Sent: Tuesday, March 01, 2011 8:25 AM
Subject: Re: FW: re-Prions David W. Colby1,* and Stanley B. Prusiner1,2 + Author Affiliations
Dear Terry Singeltary,
Thank you for your correspondence regarding the review article Stanley Prusiner and I recently wrote for Cold Spring Harbor Perspectives. Dr. Prusiner asked that I reply to your message due to his busy schedule. We agree that the transmission of CWD prions to beef livestock would be a troubling development and assessing that risk is important. In our article, we cite a peer-reviewed publication reporting confirmed cases of laboratory transmission based on stringent criteria. The less stringent criteria for transmission described in the abstract you refer to lead to the discrepancy between your numbers and ours and thus the interpretation of the transmission rate. We stand by our assessment of the literature--namely that the transmission rate of CWD to bovines appears relatively low, but we recognize that even a low transmission rate could have important implications for public health and we thank you for bringing attention to this matter.
Warm Regards, David Colby
--
David Colby, PhDAssistant ProfessorDepartment of Chemical EngineeringUniversity of Delaware
====================END...TSS==============
re-ENLARGING SPECTRUM OF PRION-LIKE DISEASES Prusiner Colby et al 2011 Prions
CWD to cattle figures CORRECTION
Greetings,
I believe the statement and quote below is incorrect ;
"CWD has been transmitted to cattle after intracerebral inoculation, although the infection rate was low (4 of 13 animals [Hamir et al. 2001]). This finding raised concerns that CWD prions might be transmitted to cattle grazing in contaminated pastures."
Please see ;
Within 26 months post inoculation, 12 inoculated animals had lost weight, revealed abnormal clinical signs, and were euthanatized. Laboratory tests revealed the presence of a unique pattern of the disease agent in tissues of these animals. These findings demonstrate that when CWD is directly inoculated into the brain of cattle, 86% of inoculated cattle develop clinical signs of the disease.
"although the infection rate was low (4 of 13 animals [Hamir et al. 2001])."
shouldn't this be corrected, 86% is NOT a low rate. ...
kindest regards,
Terry S. Singeltary Sr. P.O. Box 42 Bacliff, Texas USA 77518
Thank you!
Thanks so much for your updates/comments. We intend to publish as rapidly as possible all updates/comments that contribute substantially to the topic under discussion.
re-Prions David W. Colby1,* and Stanley B. Prusiner1,2 + Author Affiliations
1Institute for Neurodegenerative Diseases, University of California, San Francisco, San Francisco, California 94143 2Department of Neurology, University of California, San Francisco, San Francisco, California 94143 Correspondence: stanley@ind.ucsf.edu
snip...full text ;
Wednesday, January 5, 2011
ENLARGING SPECTRUM OF PRION-LIKE DISEASES Prusiner Colby et al 2011 Prions
David W. Colby1,* and Stanley B. Prusiner1,2
DATA ON 2ND CWD STRAIN
Wednesday, September 08, 2010CWD PRION CONGRESS SEPTEMBER 8-11 2010
2003
Evidence For CJD/TSE Transmission Via Dental Instruments
From Terry S. Singletary, Sr
flounder@wt.net
1-24-3
J Hosp Infect 2002 Jul;51(3):233-5 Related Articles, Links [Click here to read] Contaminated dental instruments. Smith A, Dickson M, Aitken J, Bagg J.
Infection Research Group, Glasgow Dental Hospital & School, 378 Sauchiehall Street, Glasgow, UK. a.smith@dental.gla.ac.uk
There is current concern in the UK over the possible transmission of prions via contaminated surgical instruments. Some dental instruments (endodontic files) raise particular concerns by virtue of their intimate contact with terminal branches of the trigeminal nerve. A visual assessment using a dissecting light microscope and scanning electron microscopy of endodontic files after clinical use and subsequent decontamination was performed. The instruments examined were collected from general dental practices and from a dental hospital. Seventy-six per cent (22/29) of the files retrieved from general dental practices remained visibly contaminated, compared with 14% (5/37) from the dental hospital. Current methods for decontaminating endodontic instruments used in dentistry may be of an insufficient standard to completely remove biological material. Improved cleaning methods and the feasibility of single use endodontic instruments require further investigation.
PMID: 12144804 [PubMed - indexed for MEDLINE]
J Gen Virol 1999 Nov;80 ( Pt 11):3043-7
Transmission of the 263K scrapie strain by the dental route.
Ingrosso L, Pisani F, Pocchiari M Laboratory of Virology, lstituto Superiore di Sanita, Viale Regina Elena 299, 00161 Rome, Italy.
Apart from a few cases of iatrogenic and familial human transmissible spongiform encephalopathies (TSEs) or prion diseases, the cause of Creutzfeldt-Jakob disease (CJD) remains unknown. In this paper we investigated the possibility that dental procedures may represent a potential route of infection. This was assessed by using the experimental model of scrapie in hamster. In the first part of this study we found that after intraperitoneal inoculation, oral tissues commonly involved in dental procedures (gingival and pulp tissues) bore a substantial level of infectivity. We also found high scrapie infectivity in the trigeminal ganglia, suggesting that the scrapie agent had reached the oral tissues through the sensitive terminal endings of the trigeminal nerves. In the second part of the study we inoculated a group of hamsters in the tooth pulp and showed that all of them developed scrapie disease. In these animals, we detected both infectivity and the pathological prion protein (PrPsc) in the trigeminal ganglion homolateral to the site of injection but not in the controlateral one. This finding suggests that the scrapie agent, and likely other TSE agents as well, spreads from the buccal tissues to the central nervous system through trigeminal nerves. Although these findings may not apply to humans affected by TSEs, they do raise concerns about the possible risk of transmitting these disorders through dental procedures. Particular consideration should be taken in regard to new variant CJD patients because they may harbour more infectivity in peripheral tissues than sporadic CJD patients.
PMID: 10580068
a simple auto-claving just will not kill this agent, considering the fact this agent can survive ashing to 600 degrees celsius;
New studies on the heat resistance of hamster-adapted scrapie agent: Threshold survival after ashing at 600°C suggests an inorganic template of replication
Paul Brown*,dagger , Edward H. RauDagger , Bruce K. Johnson*, Alfred E. Bacote*, Clarence J. Gibbs Jr.*, and D. Carleton Gajdusek§ * Laboratory of Central Nervous System Studies, National Institute of Neurological Disorders and Stroke, and Dagger Environmental Protection Branch, Division of Safety, Office of Research Services, National Institutes of Health, Bethesda, MD 20892; and § Institut Alfred Fessard, Centre National de la Recherche Scientifique, 91198 Gif sur Yvette, France Contributed by D. Carleton Gajdusek, December 22, 1999
Abstract
One-gram samples from a pool of crude brain tissue from hamsters infected with the 263K strain of hamster-adapted scrapie agent were placed in covered quartz-glass crucibles and exposed for either 5 or 15 min to dry heat at temperatures ranging from 150°C to 1,000°C. Residual infectivity in the treated samples was assayed by the intracerebral inoculation of dilution series into healthy weanling hamsters, which were observed for 10 months; disease transmissions were verified by Western blot testing for proteinase-resistant protein in brains from clinically positive hamsters. Unheated control tissue contained 9.9 log10LD50/g tissue; after exposure to 150°C, titers equaled or exceeded 6 log10LD50/g, and after exposure to 300°C, titers equaled or exceeded 4 log10LD50/g. Exposure to 600°C completely ashed the brain samples, which, when reconstituted with saline to their original weights, transmitted disease to 5 of 35 inoculated hamsters. No transmissions occurred after exposure to 1,000°C. These results suggest that an inorganic molecular template with a decomposition point near 600°C is capable of nucleating the biological replication of the scrapie agent.
transmissible spongiform encephalopathy | scrapie | prion | medical waste | incineration
Introduction
The infectious agents responsible for transmissible spongiform encephalopathy (TSE) are notoriously resistant to most physical and chemical methods used for inactivating pathogens, including heat. It has long been recognized, for example, that boiling is ineffective and that higher temperatures are most efficient when combined with steam under pressure (i.e., autoclaving). As a means of decontamination, dry heat is used only at the extremely high temperatures achieved during incineration, usually in excess of 600°C. It has been assumed, without proof, that incineration totally inactivates the agents of TSE, whether of human or animal origin. It also has been assumed that the replication of these agents is a strictly biological process (1), although the notion of a "virus" nucleant of an inorganic molecular cast of the infectious beta -pleated peptide also has been advanced (2). In this paper, we address these issues by means of dry heat inactivation studies.
see full text:
Greetings again,
please believe me when i tell you this goes far far beyond the hamburger/deerburger/elkburger/sheepburger. Pandora's box of the demented has been opened for decades, closing it will be most impossible with current safeguards. until they can perfect a test, not only to confirm TSE agent, but also to differentiate between the many differnt strains (there are over 20 in sheep scrapie, and sheep scrapie is the sole model for CJD studies), they then will have to perfect a test that will differentiate between the many different routes. so, as you can see, this could very well take many more decades to answer these questions. but in the mean time, i will not now or ever accept the 'spontaneous/sporadic' theory without any source and route. i plan to continue to fan the fire until we know what killed our loved ones...
CJD/TSEs MUST BE MADE REPORTABLE NATIONALLY, SUPPORTED WITH A CJD QUESTIONNAIRE TO EVERY VICTIM/FAMILY THAT ASK REAL QUESTIONS PERTAINING TO ROUTE/SOURCE...TSS
Terry S. Singeltary Sr. P.O. Box 42 Bacliff, Texas USA
Friday, January 01, 2010
Human Prion Diseases in the United States
-------------------- BSE-L@LISTS.AEGEE.ORG --------------------
Singeltary submission to PLOS ;
No competing interests declared.
see full text ;
Tuesday, November 08, 2011
Can Mortality Data Provide Reliable Indicators for Creutzfeldt-Jakob Disease Surveillance? A Study in France from 2000 to 2008 Vol. 37, No. 3-4, 2011 Original Paper
Conclusions:These findings raise doubt about the possibility of a reliable CJD surveillance only based on mortality data.
Views & Reviews
Monitoring the occurrence of emerging forms of Creutzfeldt-Jakob disease in the United States
Ermias D. Belay, MD, Ryan A. Maddox, MPH, Pierluigi Gambetti, MD and Lawrence B. Schonberger, MD
+ Author Affiliations
From the Division of Viral and Rickettsial Diseases (Drs. Belay and Schonberger and R.A. Maddox), National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA; and National Prion Disease Pathology Surveillance Center (Dr. Gambetti), Division of Neuropathology, Institute of Pathology, Case Western Reserve University, Cleveland, OH.
Address correspondence and reprint requests to Dr. Ermias D. Belay, 1600 Clifton Road, Mailstop A-39, Atlanta, GA 30333.
26 March 2003
Terry S. Singeltary, retired (medically) CJD WATCH
I lost my mother to hvCJD (Heidenhain Variant CJD). I would like to comment on the CDC's attempts to monitor the occurrence of emerging forms of CJD. Asante, Collinge et al [1] have reported that BSE transmission to the 129-methionine genotype can lead to an alternate phenotype that is indistinguishable from type 2 PrPSc, the commonest sporadic CJD. However, CJD and all human TSEs are not reportable nationally. CJD and all human TSEs must be made reportable in every state and internationally. I hope that the CDC does not continue to expect us to still believe that the 85%+ of all CJD cases which are sporadic are all spontaneous, without route/source. We have many TSEs in the USA in both animal and man. CWD in deer/elk is spreading rapidly and CWD does transmit to mink, ferret, cattle, and squirrel monkey by intracerebral inoculation. With the known incubation periods in other TSEs, oral transmission studies of CWD may take much longer. Every victim/family of CJD/TSEs should be asked about route and source of this agent. To prolong this will only spread the agent and needlessly expose others. In light of the findings of Asante and Collinge et al, there should be drastic measures to safeguard the medical and surgical arena from sporadic CJDs and all human TSEs. I only ponder how many sporadic CJDs in the USA are type 2 PrPSc?
Reply to Singletary
Ryan A. Maddox, MPH Ermias D. Belay, MD, Lawrence B. Schonberger, MD Centers for Disease Control and Prevention Atlanta GA
Mr. Singletary raises several issues related to current Creutzfeldt- Jakob disease (CJD) surveillance activities. Although CJD is not a notifiable disease in most states, its unique characteristics, particularly its invariably fatal outcome within usually a year of onset, make routine mortality surveillance a useful surrogate for ongoing CJD surveillance.[1] In addition, because CJD is least accurately diagnosed early in the course of illness, notifiable-disease surveillance could be less accurate than, if not duplicative of, current mortality surveillance.[1] However, in states where making CJD officially notifiable would meaningfully facilitate the collection of data to monitor for variant CJD (vCJD) or other emerging prion diseases, CDC encourages the designation of CJD as a notifiable disease.[1] Moreover, CDC encourages physicians to report any diagnosed or suspected CJD cases that may be of special public health importance (e.g., vCJD, iatrogenic CJD, unusual CJD clusters).
As noted in our article, strong evidence is lacking for a causal link between chronic wasting disease (CWD) of deer and elk and human disease,[2] but only limited data seeking such evidence exist. Overall, the previously published case-control studies that have evaluated environmental sources of infection for sporadic CJD have not consistently identified strong evidence for a common risk factor.[3] However, the power of a case-control study to detect a rare cause of CJD is limited, particularly given the relatively small number of subjects generally involved and its long incubation period, which may last for decades. Because only a very small proportion of the US population has been exposed to CWD, a targeted surveillance and investigation of unusual cases or case clusters of prion diseases among persons at increased risk of exposure to CWD is a more efficient approach to detecting the possible transmission of CWD to humans. In collaboration with appropriate local and state health departments and the National Prion Disease Pathology Surveillance Center, CDC is facilitating or conducting such surveillance and case- investigations, including related laboratory studies to characterize CJD and CWD prions.
Mr. Singletary also expresses concern over a recent publication by Asante and colleagues indicating the possibility that some sporadic CJD cases may be attributable to bovine spongiform encephalopathy (BSE).[4] The authors reported that transgenic mice expressing human prion protein homozygous for methionine at codon 129, when inoculated with BSE prions, developed a molecular phenotype consistent with a subtype of sporadic CJD. Although the authors implied that BSE might cause a sporadic CJD-like illness among persons homozygous for methionine, the results of their research with mice do not necessarily directly apply to the transmission of BSE to humans. If BSE causes a sporadic CJD-like illness in humans, an increase in sporadic CJD cases would be expected to first occur in the United Kingdom, where the vast majority of vCJD cases have been reported. In the United Kingdom during 1997 through 2002, however, the overall average annual mortality rate for sporadic CJD was not elevated; it was about 1 case per million population per year. In addition, during this most recent 6-year period following the first published description of vCJD in 1996, there was no increasing trend in the reported annual number of UK sporadic CJD deaths.[3, 5] Furthermore, surveillance in the UK has shown no increase in the proportion of sporadic CJD cases that are homozygous for methionine (Will RG, National CJD Surveillance Unit, United Kingdom, 2003; personal communication).
References
1. Gibbons RV, Holman RC, Belay ED, Schonberger LB. Diagnosis and reporting of Creutzfeldt-Jakob disease. JAMA 2001;285:733-734.
2. Belay ED, Maddox RA, Gambetti P, Schonberger LB. Monitoring the occurrence of emerging forms of Creutzfeldt-Jakob disease in the United States. Neurology 2003;60:176-181.
3. Belay ED. Transmissible spongiform encephalopathies in humans. Annu Rev Microbiol 1999;53:283-314.
4. Asante EA, Linehan JM, Desbruslais M, et al. BSE prions propagate as either variant CJD-like or sporadic CJD-like prion strains in transgenic mice expressing human prion protein. EMBO J 2002;21:6358-6366.
5. The UK Creutzfeldt-Jakob Disease Surveillance Unit. CJD statistics. Available at: http://www.cjd.ed.ac.uk/figures.htm. Accessed February 18, 2003.
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. FREE FULL TEXT
2 January 2000
British Medical Journal
U.S. Scientist should be concerned with a CJD epidemic in the U.S., as well
15 November 1999
British Medical Journal
vCJD in the USA * BSE in U.S.
Saturday, January 2, 2010
Human Prion Diseases in the United States January 1, 2010 ***FINAL***
14th ICID International Scientific Exchange Brochure -
Final Abstract Number: ISE.114
Session: International Scientific Exchange
Transmissible Spongiform encephalopathy (TSE) animal and human TSE in North America update October 2009
T. Singeltary
Bacliff, TX, USA
Background:
An update on atypical BSE and other TSE in North America. Please remember, the typical U.K. c-BSE, the atypical l-BSE (BASE), and h-BSE have all been documented in North America, along with the typical scrapie's, and atypical Nor-98 Scrapie, and to date, 2 different strains of CWD, and also TME. All these TSE in different species have been rendered and fed to food producing animals for humans and animals in North America (TSE in cats and dogs ?), and that the trading of these TSEs via animals and products via the USA and Canada has been immense over the years, decades.
Methods:
12 years independent research of available data
Results:
I propose that the current diagnostic criteria for human TSEs only enhances and helps the spreading of human TSE from the continued belief of the UKBSEnvCJD only theory in 2009. With all the science to date refuting it, to continue to validate this old myth, will only spread this TSE agent through a multitude of potential routes and sources i.e. consumption, medical i.e., surgical, blood, dental, endoscopy, optical, nutritional supplements, cosmetics etc.
Conclusion:
I would like to submit a review of past CJD surveillance in the USA, and the urgent need to make all human TSE in the USA a reportable disease, in every state, of every age group, and to make this mandatory immediately without further delay. The ramifications of not doing so will only allow this agent to spread further in the medical, dental, surgical arena's. Restricting the reporting of CJD and or any human TSE is NOT scientific. Iatrogenic CJD knows NO age group, TSE knows no boundaries. I propose as with Aguzzi, Asante, Collinge, Caughey, Deslys, Dormont, Gibbs, Gajdusek, Ironside, Manuelidis, Marsh, et al and many more, that the world of TSE Transmissible Spongiform Encephalopathy is far from an exact science, but there is enough proven science to date that this myth should be put to rest once and for all, and that we move forward with a new classification for human and animal TSE that would properly identify the infected species, the source species, and then the route.
Saturday, July 23, 2011
CATTLE HEADS WITH TONSILS, BEEF TONGUES, SPINAL CORD, SPECIFIED RISK MATERIALS (SRM's) AND PRIONS, AKA MAD COW DISEASE
Saturday, November 6, 2010
TAFS1 Position Paper on Position Paper on Relaxation of the Feed Ban in the EU Berne, 2010 TAFS
INTERNATIONAL FORUM FOR TRANSMISSIBLE ANIMAL DISEASES AND FOOD SAFETY a non-profit Swiss Foundation
Archive Number 20101206.4364 Published Date 06-DEC-2010 Subject PRO/AH/EDR> Prion disease update 2010 (11)
PRION DISEASE UPDATE 2010 (11)
Sunday, September 25, 2011
Mad Cow Scaremongers
Mad Cow Scaremongers by Terry S. Singeltary Sr. a review of the TSE prion agent 2003-2011
Saturday, June 25, 2011
Transmissibility of BSE-L and Cattle-Adapted TME Prion Strain to Cynomolgus Macaque
"BSE-L in North America may have existed for decades"
Over the next 8-10 weeks, approximately 40% of all the adult mink on the farm died from TME.
snip...
The rancher was a ''dead stock'' feeder using mostly (>95%) downer or dead dairy cattle...
Sunday, June 26, 2011
Risk Analysis of Low-Dose Prion Exposures in Cynomolgus Macaque
PRICE OF MAD COW TSE PRION POKER GOES UP $$$
Saturday, December 3, 2011
Isolation of Prion with BSE Properties from Farmed Goat Volume 17, Number 12—December 2011
Saturday, November 19, 2011
Novel Prion Protein in BSE-affected Cattle, Switzerland
Friday, November 30, 2007
CJD QUESTIONNAIRE USA CWRU AND CJD FOUNDATION
LAYPERSON
Terry S. Singeltary Sr. P.O. Box 42 Bacliff, Texas USA 77518
kind regards, terry
