Surveillance and simulation of bovine spongiform encephalopathy and scrapie in small ruminants in Switzerland
Surveillance and simulation of bovine spongiform encephalopathy and scrapie in small ruminants in Switzerland
Chantal Hausermann , Heinzpeter Schwermer , Anna Oevermann , Alice Nentwig , Andreas Zurbriggen , Dagmar Heim and Torsten Seuberlich
BMC Veterinary Research 2010, 6:20doi:10.1186/1746-6148-6-20
Published: 18 April 2010
Abstract (provisional)
Background
After bovine spongiform encephalopathy (BSE) emerged in European cattle livestock in 1986 a fundamental question was whether the agent established also in the small ruminants' population. In Switzerland transmissible spongiform encephalopathies (TSEs) in small ruminants have been monitored since 1990. While in the most recent TSE cases a BSE infection could be excluded, for historical cases techniques to discriminate scrapie from BSE had not been available at the time of diagnosis and thus their status remained unclear. We herein applied state-of-the-art techniques to retrospectively classify these animals and to re-analyze the affected flocks for secondary cases. These results were the basis for models, simulating the course of TSEs over a period of 70 years. The aim was to come to a statistically based overall assessment of the TSE situation in the domestic small ruminant population in Switzerland.
Results
In sum 16 TSE cases were identified in small ruminants in Switzerland since 1981, of which eight were atypical and six were classical scrapie. In two animals retrospective analysis did not allow any further classification due to the lack of appropriate tissue samples. We found no evidence for an infection with the BSE agent in the cases under investigation. In none of the affected flocks, secondary cases were identified. A Bayesian prevalence calculation resulted in most likely estimates of one case of BSE, five cases of classical scrapie and 21 cases of atypical scrapie per 100'000 small ruminants. According to our models none of the TSEs is considered to cause a broader epidemic in Switzerland. In a closed population, they are rather expected to fade out in the next decades or, in case of a sporadic origin, may remain at a very low level.
Conclusions
In summary, these data indicate that despite a significant epidemic of BSE in cattle, there is no evidence that BSE established in the small ruminant population in Switzerland. Classical and atypical scrapie both occur at a very low level and are not expected to escalate into an epidemic. In this situation the extent of TSE surveillance in small ruminants requires reevaluation based on cost-benefit analysis.
http://www.biomedcentral.com/1746-6148/6/20/abstract
Discussion
In the past 30 years 16 cases of TSE have been identified in Swiss sheep and goats. Seven cases date back to the 1990s, the decade of the highest BSE incidence in domestic cattle; it was not clear whether they were scrapie cases as assumed or rather the result of a BSE infection. Here we show now that in five of these animals the IHC labeling pattern was consistent with classical scrapie. Still in two sheep a TSE could not be confirmed by IHC. However, a definite evaluation of both cases is not feasible because either diagnostic target sites, obex for classical scrapie and BSE and cerebellar cortex for atypical scrapie, are missing or frozen unfixed material allowing proceeding to alternative tests such as ELISA or WB, is not available. The result of the present study together with previously published work on the biochemical PrPd -typing of the more recent TSE isolates detected in 2004/2005 [24] indicate no evidence for BSE in the domestic small ruminant population in Switzerland. Nevertheless, the data derived from passive surveillance need careful interpretation, because they largely depend on disease awareness and compliance with the regulations. It is therefore difficult to assess how many suspicious sheep and goats had been missed or were not reported in the past. However, based on the results of the active surveillance that in principle overcomes these limitations, it appears highly unlikely that BSE became established in the small ruminant population in Switzerland.
Classical scrapie has never been considered an important threat in Switzerland. Indeed, the surveillance data imply that it is a very rare disease. Secondary cases were not found in the present study. Moreover, all scrapie cases were geographically separated and epidemiological follow-up investigations found no relation between the affected flocks (unpublished data). Disease transmission between and within flocks therefore appears very inefficient. A factor that may account for such a situation is a
19
very low frequency of animals with classical scrapie susceptible PRNP genotypes. Unfortunately several attempts to extract genomic DNA from wax embedded tissues of the historic cases and their flock mates failed (unpublished data). However, for those of case S1/RS, DNA samples were available and more than half of them revealed a classical scrapie susceptible genotype. Moreover, in some of the affected sheep flocks (see additional file 2) and also in previous investigations it has been documented that such genotypes occur at rates ranging from approximately 30% to 60% in different domestic sheep breeds [33]. It can therefore be assumed that a proportion of the flock mates of the historic cases were indeed of susceptible genotypes. Environmental contamination is considered to substantially contribute to the persistence of classical scrapie in affected populations. There is evidence that the agent may remain infectious over years, if not decades, in the environment [38,39]. In Switzerland this factor does not appear to play an important role. This could be related to relatively small herd sizes and a low percentage of intensive farming in the Swiss small ruminant sector and differences in herd management and lambing practice compared to other countries [40].
It was rather unexpected, that only one case of classical scrapie has been identified in the 2004-2005 active surveillance program, which is considered much more efficient compared to passive surveillance alone. A possible explanation is that the prevalence of classical scrapie decreased compared to the mid 1990s when most of the other cases were identified. This could be the result of a very efficient passive surveillance and successful disease control or may be related to other yet unidentified factors that affect disease transmission. An interesting finding was that the two classical scrapie affected goats (IDs 15355 and 22614) originated from CAEV infected flocks. CAEV is closely related, if not identical, to maedi-visna virus in sheep; both belong to the genus lentivirus. There are several lines of evidence
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indicating that lentivirus infections play a role in the pathogenesis and transmission of scrapie [41-43]. CAE has been subject to mandatory eradication policies in Switzerland since 1994 and thereupon its prevalence has been drastically reduced. This situation may at least partially explain the absence of classical scrapie in goats in the 2004/2005 active surveillance sample. Although scientifically not proven, one could also speculate that the ban on MBM in ruminant feed since 1990 might have prevented recycling not only of BSE but also of classical scrapie to sheep and goats. Finally, we cannot exclude that single cases of classical scrapie eventually result from spontaneous PrPc to PrPd conversion events and occur as a sporadic TSE similar to sporadic TSEs in humans. However, at the time being such scenarios are highly speculative.
snip...
Conclusions
In the wake of the BSE epidemic in cattle, fundamental concerns regarding a possible maintenance of the agent in the small ruminant population were raised. Based on the present study it is considered highly unlikely that the BSE agent was endemic in Swiss sheep and goats at the time when BSE in cattle faded out in 2006.
24
However, statistically we cannot exclude that single cases occurred. In addition, the prevalence of classical scrapie was calculated as very low, but atypical scrapie was found at a higher rate. Even the forecast of the prevalence of small ruminant TSEs in a simulation model for the next decades in an unlikely worst-case scenario predicted that an epidemic of either type of small ruminant TSE in Switzerland cannot be expected. In view of the high costs related to active TSE surveillance in small ruminants the design of such programs must be subject of cost-benefit analysis. If this finally results in pure passive disease surveillance schemes, their efficiency must be provided by a high disease awareness and compliance.
http://www.biomedcentral.com/content/pdf/1746-6148-6-20.pdf
> In summary, these data indicate that despite a significant epidemic of BSE in cattle
Category III: likely to present a BSE risk, even if not confirmed, or presenting a low level of confirmed BSE risk
Albania
Cyprus
Czech Republic
Estonia
Hungary
Lithuania
Poland
Slovak republic
Switzerland
http://ec.europa.eu/dgs/health_consumer/library/press/press123_en.html
BSE prions propagate as either variant CJD-like or sporadic CJD-like prion strains in transgenic mice expressing human prion protein
Emmanuel A. Asante, Jacqueline M. Linehan, Melanie Desbruslais, Susan Joiner, Ian Gowland, Andrew L. Wood, Julie Welch, Andrew F. Hill, Sarah E. Lloyd, Jonathan D.F. Wadsworth, and John Collinge1 MRC Prion Unit and Department of Neurodegenerative Disease, Institute of Neurology, University College, Queen Square, London WC1N 3BG, UK 1Corresponding author e-mail: j.collinge@prion.ucl.ac.ukReceived August 1, 2002; Revised September 24, 2002; Accepted October 17, 2002.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC136957/?tool=pubmed
CJD RISING SWITZERLAND
CJD is a predominantly sporadic disorder but can also occur as a dominantly inherited or infective condition. Only one of the 26 most recent confirmed cases was identified as carrying a disease related mutation of the PRNP gene, none had identifiable iatrogenic exposure, and none resembled variant CJD. Thus 25 of the 26 cases appear to be sporadic cases. Sporadic CJD is distributed worldwide with a reported incidence of about one in a million per year. Raised awareness of the disease in recent years could account for an increase in reported cases of CJD, although neither an increase in the average age of patients nor more frequent recognition of CJD amongst residents of nursing homes (where dementing illness is prevalent and misdiagnosis might be expected) were seen in the Swiss cases. Moreover, improved ascertainment as an explanation for the observed increase would imply levels of under-reporting in countries other than Switzerland, which appear implausible. The authors of the Lancet report suggest that the rise in cases might be due to some form of unidentified iatrogenic transmission or to exposure to a zoonotic source of infection, though cases do not resemble variant Creutzfeldt-Jakob disease (vCJD). The ongoing surveillance of CJD in Switzerland and the rest of Europe is essential to monitor the situation to see if this rise is sustained in Switzerland, and if a similar rise occurs in other countries (see http://www.eurocjd.ed.ac.uk).
http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=1921
Prion data suggest BSE link to sporadic CJD Declan Butler
Predicting the number of cases of Creutzfeldt-Jakob disease (CJD) in people as a result of transmission of bovine spongiform encephalopathy (BSE) has just got more difficult.Whereas it was thought that BSE only caused a new form of the disease called variant CJD (vCJD), a study in mice from a team led by John Collinge at University College London suggests that it may also cause a disease indistinguishable from the commonest form of classical, or 'sporadic', CJD (E.
http://www.nature.com/nature/journal/v420/n6915/full/420450a.html
IF we look at sporadic incidence of CJD in UK from 1993 to 2003, the incidence rose from 37 in 1993 to 77 in 2003. THIS seems to show an increase to me? I do not understand the statement ;
However, in the period following the first published description of vCJD in 1996, there was no increasing trend in the reported annual number of U.K. sporadic CJD deaths (52).
IF we go further and look at some of the other documented BSE countries, you will the increase of sporadic CJD there as well ;
Canada from 2 to 25
France from 35 to 108
Germany 21+ to 96
Italy 27 to 76
Switerland 8 to 18 in 2001 and 2002
http://www.eurocjd.ed.ac.uk/sporadic.htm
Switzerland sporadic CJD ;
Swiss rise in CJD raises concerns over possible BSE link [LONDON] THE LANCET
Plaque attack: Swiss patients have spongiform patterns in the brain typical of sporadic CJD. The number of people dying from Creutzfeldt-Jakob disease (CJD) has risen sharply in Switzerland -- sparking fears of a possible link with bovine spongiform encephalopathy (BSE).
BSE is thought to be the cause of a distinctive form of the brain-wasting disease known as variant CJD. The Swiss cases, in contrast, are standard 'sporadic' CJD. Each year between 1997 and 2000, no more than 11 Swiss people developed CJD. But 19 cases were reported in 2001, and seven were recorded in the first quarter of this year. This is some four times higher than the incidence elsewhere, reports a team led by Adriano Aguzzi of the University Hospital Zurich (M. Glatzel et al. Lancet 360, 139-141; 2002).
The increase could be a mere statistical blip, or it may be due to increased awareness of the disease leading to more diagnoses. More disturbing is the possibility that the cases are linked to the consumption of BSE-infected meat products -- which would mean that the BSE agent can cause two distinct forms of CJD.
Possible links between the Swiss CJD cases and BSE will now be explored by strain-typing experiments in which the disease is transmitted to mice. These tests will take at least a year to complete. "It's the best way to establish or exclude any suspected link," says Moira Bruce of the UK Institute for Animal Health's Neuropathogenesis Unit in Edinburgh.
======================================
Experiences in England and Switzerland -- two countries that discovered mad cow disease in their cattle -- have heightened concerns about the possibility some cases of sporadic CJD are due to consuming mad-cow-tainted beef. Both countries have reported increases in sporadic CJD since mad cow was first detected in British herds in 1986.
Switzerland discovered last year its CJD rate was twice that of any other country in the world. Switzerland had been seeing about eight to 11 cases per year from 1997 to 2000. Then the incidence more than doubled, to 19 cases in 2001 and 18 cases in 2002.
http://www.upi.com/view.cfm?StoryID=20030721-102924-4786r
Mouse model sheds new light on human prion disease
snip...
Professor John Collinge said We are not saying that all or even most cases of sporadic CJD are as a result of BSE exposure, but some more recent cases may be the incidence of sporadic CJD has shown an upward trend in the UK over the last decade. While most of this apparent increase may be because doctors are now more aware of CJD and better at diagnosing it, serious consideration should be given to a proportion of this rise being BSE-related. Switzerland, which has had a substantial BSE epidemic, has noted a sharp recent increase in sporadic CJD.
snip...
http://www.mrc.ac.uk/txt/index/public-interest/public-news-4/public-news_archive/public-news-archive_nov_dec_02/public-bse_and_sporadic_cjd.htm
BMC Public Health. 2009; 9: 18. Published online 2009 January 14. doi: 10.1186/1471-2458-9-18.
PMCID: PMC2637857
Copyright © 2009 Ruegger et al; licensee BioMed Central Ltd.
A case-control study of sporadic Creutzfeldt-Jakob disease in Switzerland: analysis of potential risk factors with regard to an increased CJD incidence in the years 2001–2004
Jessica Ruegger,#1 Katharina Stoeck,#2,3 Lorenz Amsler,4,5 Thomas Blaettler,2,6 Marcel Zwahlen,7 Adriano Aguzzi,2 Markus Glatzel,2,8 Klaus Hess,1 and Tobias Eckert4,9 1Department of Neurology, University Hospital Zurich, Zurich, Switzerland 2Institute of Neuropathology, University Hospital Zurich, Zurich, Switzerland 3Department of Neurology, University Hospital Hamburg-Eppendorf, Hamburg-Eppendorf, Hamburg, Germany 4Federal Office of Public Health, Bern, Switzerland 5CSL Behring, Bern, Switzerland 6Bristol-Myers Squibb, Wallingford, CT, USA 7Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland 8Institute of Neuropathology, University Hospital Hamburg-Eppendorf, Hamburg-Eppendorf, Hamburg, Germany 9Swiss Tropical Institute, Basel, Switzerland Corresponding author. #Contributed equally. Jessica Ruegger: jessica.ruegger@gmail.com ; Katharina Stoeck: kstoeck@uke.uni-hamburg.de ; Lorenz Amsler: Lorenz.Amsler@cslbehring.com ; Thomas Blaettler: thomas.blaettler@bms.com ; Marcel Zwahlen: zwahlen@ispm.unibe.ch ; Adriano Aguzzi: adriano.aguzzi@usz.ch ; Markus Glatzel: m.glatzel@uke.uni-hamburg.de ; Klaus Hess: k_h@bluewin.ch ; Tobias Eckert: tobias.eckert@bag.admin.ch
Received July 11, 2008; Accepted January 14, 2009. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
Background
In 2001, the observed annual mortality from Creutzfeldt-Jakob disease (CJD) in Switzerland increased from less than 1.5 to 2.6 per million inhabitants. An underlying cause could not be identified.
Methods
To analyse potential risk factors for sCJD in Switzerland, close relatives of 69 sCJD-patients and 224 frequency age-matched controls were interviewed in a case-control study using a standardised questionnaire. 135 potential risk factors including socio-demographics, medical history, occupation and diet were analysed by logistic regression adjusting for age, sex and education.
Results
sCJD patients were more likely to have travelled abroad, worked at an animal laboratory, undergone invasive dental treatment, orthopaedic surgery, ophthalmologic surgery after 1980, regular GP visits, taken medication regularly, and consumed kidney. No differences between patients and controls were found for residency, family history, and exposure to environmental and other dietary factors.
Conclusion
Although some factors were significantly more frequent among sCJD-cases, this study did not reveal specific explanations for the increased incidence of deaths due to sporadic CJD observed in Switzerland since 2001. Results have to be interpreted with caution due to multiple testing and possible recall bias in association with a long incubation period. The most plausible reason for the increase in Swiss sCJD cases after 2000 is an improved case ascertainment. Therefore, underreporting of cases might well have occurred before the year 2001, and the "real" yearly incidence of sCJD might not be lower than, but rather above 2 per million inhabitants.
snip...
Discussion
This study evaluated a wide range of possible risk factors as risk factors for sCJD-cases observed in Switzerland between 2001 and 2004. If some of the positively associated risk factors were truly causal and would have become more frequent in recent years and decades, then they might have contributed to the increase in sCJD-cases in Switzerland. Although some analysed factors were significantly more frequent in the group of sCJD patients, the results of this case-control study have not produced unequivocal evidence for specific environmental or iatrogenic risk factors for sCJD, and thus could not reveal a specific explanation for the increased incidence. In interpreting the results, one has to bear in mind that with a significance level set at 5%, on average one in twenty results will be significant, by chance alone.
***
Starting with the hypothesis of a zoonotic cause similar to the development of vCJD by consumption of BSE-contaminated material, the present study does not demonstrate a clearly increased risk for sCJD with respect to dietary habits. Although previous studies revealed that consumption of several meat products was increased in sCJD cases compared to controls,[26,27] no such clear differences for any of the twenty diet-related exposures were found in our as well as in earlier studies. [28-30] Consistent with previous studies, no significant differences between sCJD patients and controls was found with respect to occupational exposures, including work in animal farming or in the meat industry in the present study. One exception was work in an animal laboratory. [27-31] Some findings of earlier studies which revealed higher frequencies of sCJD among butchers,[32] among those exposed to leather products, to fertiliser consisting of hoofs and horns,[27] and to farm-stays for any length of time,[31] could not be reproduced in this study. Contrary to the hypothesis of a zoonotic cause, earlier studies did not link pet animals possession to increased risk. [27-30] Patients in this study even less often owned cats or pet rodents. Travelling abroad was significantly more frequent in sCJD patients. Controls, however, travelled more frequently to the United Kingdom where risk for vCJD was elevated and to tropical destinations where some infectious diseases are more prevalent than in Switzerland. No differences in age, sex, place of birth and living or family history of dementia were found. These results are consistent with data from previous studies.[26,28,29] In contrast to earlier studies, sCJD-patients in our study had completed less years of education.[26,28] Only 45% of the cases had ten or more school years, whereas this figure was at 71% among the controls. These findings might be due to recall bias which can occur when interviewing proxy persons. However, another neurodegenerative disease, Alzheimer's disease has been shown to be observed more frequently in persons with lower levels of education.[33]
***
Concerning the hypothesis of an iatrogenic cause, sCJD cases in this study significantly more often had undergone orthopaedic and ophthalmologic surgery, invasive dental treatment as well as regular medical treatment. In previous studies, physical injuries and stressful life events such as surgical procedures,[23,28,30,31,34,35] and work in a medical profession[32] have been found to constitute a risk factor for sCJD. In particular, head surgery and trauma to other body parts were identified.[36] In contrast to the present study, however, orthopaedic surgery and invasive dental treatments per se were not associated with an elevated risk for sCJD before.[27,28,31,36] One could speculate that the use of surgical instruments as well as a potentially higher rate of blood transfusions in orthopaedic surgery may explain these findings. Receiving blood transfusions has been demonstrated to be a potential route of vCJD transmission.[20] The development of vCJD involves a peripheral route of prion transmission to the CNS. In sCJD, however, the disease most likely starts in the brain, even though recently, prions have been detected in peripheral organs such as the spleen and skeletal muscles of sCJD patients.[37] Blood transfusions, however, were not associated with sCJD in the present study. Interestingly, blood donation was less frequently observed in sCJD patients than in controls. Correspondingly, neither receiving blood transfusions nor blood donation was identified as a risk factor for sCJD in previous studies.[23,26,38,39] Cigarette smoking was more frequent in controls (29%) than in sCJD patients (13%) or in the general population, a finding which points to some bias in the selection of controls. A previous analysis did not find any association with smoking.[26]
***
Recently, the heightened incidence of sCJD in Switzerland was found to be associated with a shift in clinicopathological profiles, in that sporadic CJD patients from the cohort with elevated sporadic CJD incidence presented with a higher frequency of rare sporadic CJD-subtypes (MV2, VV2). Patients of these subtypes were significantly older and showed a skewed male/female ratio when compared to patients of identical sporadic CJD-types or to patients from the 1996–2000 cohort.[22]
The third hypothesis to explain the increase in annual mortality rates from sCJD in Switzerland between 2001 and 2004 is a better case ascertainment. Over recent years in Europe, as a general tendency incidences have been rising, however not to such extent as in Switzerland. Given that our results do not support strong evidence for the hypotheses of a zoonotic or iatrogenic cause, ascertainment bias due to a heightened perception and awareness of the disease in physicians must be regarded as the most likely cause for the observed increase. One factor that might be jointly responsible for this increase might be altered reporting requirements in 1999. Since that year all suspected cases in Switzerland had to be reported. In this respect, also the role of chance must be considered, as it is possible that the observed increase of Swiss sCJD-deaths was due to random fluctuation. The rise in annual mortality rate from the years before 2000 to the period 2001–2004, however, was statistically significant, and therefore, chance must be considered a less likely explanation. In the most recent years, the observed incidence in sCJD deaths (2005: 10; 2006: 13, 2007: 15) dropped to levels just slightly above those before 2000. When recent incidence data until 2007 are included, however, the rise in the annual mortality rate after 2001 was still significant. The sudden increase in 2001 and the slow decrease afterwards are well in line with the media coverage of the CJD topic in the respective years.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2637857/?tool=pubmed
Finally the authors consider the possibility that CJD in Switzerland is related to a prion epizootic, and pay considerable attention to this possibility since between 1995 and 1998, Switzerland reported a larger incidence of BSE than did all other continental European countries (415 cases between 1990 and 2002). Exposure to BSE-infected products might have taken place mainly before high-risk bovine food products were banned from the human food chain in 1990. However, BSE is thought to cause variant CJD [abbreviated as vCJD or CJD (new var.) in ProMED-mail] rather than sporadic CJD, yet all evidence indicates that none of the Swiss cases fulfill the diagnostic criteria of vCJD. Swiss CJD could be related to BSE only if the strain of Swiss BSE prion differs from the strain of BSE prevalent in the UK. Available data, though limited, suggest that this is not the case.
At present there is no evidence that the Swiss CJD cases might result from transmission of BSE to people after one or more serial passages through species other than cattle. Scrapie is exceedingly rare in Switzerland: only 7 cases have been reported in the past 10 years. Chronic wasting disease of deer has not been reported in Europe, although surveillance data on transmissible spongiform encephalopathies in European game are incomplete.
All recognized clinical and molecular markers combine to indicate that none of the Swiss patients developed vCJD. The authors conclude that the elucidation of the underlying chain of events is a national research priority, and may uncover previously unrecognized modes of prion infection and transmission. It remains to be seen whether this increase in the incidence of CJD in Switzerland will be sustained, or whether it represent a statistical anomaly. According to Will RG, et al. (Ann Neurol 1998; 43: 763-767) there was a doubling in the annual death rates for sporadic CJD in the United Kingdom between the 1980s and the 1990s, and similar increases in the apparent death rates for sporadic Creutzfeldt-Jakob disease had occurred in other European countries, attributable to improvement in diagnosis. - Mod.CP].................as/mpp/cp/mpp
http://www.promedmail.org/pls/otn/f?p=2400:1202:307098::NO::F2400_P1202_CHECK_DISPLAY,F2400_P1202_PUB_MAIL_ID:X,18755
Saturday, February 14, 2009
A case-control study of sporadic Creutzfeldt-Jakob disease in Switzerland: analysis of potential risk factors with regard to an increased CJD incidence in the years 2001–2004
http://creutzfeldt-jakob-disease.blogspot.com/2009/02/case-control-study-of-sporadic.html
Monday, December 14, 2009
Similarities between Forms of Sheep Scrapie and Creutzfeldt-Jakob Disease Are Encoded by Distinct Prion Types
hmmm, this is getting interesting now...
Sporadic CJD type 1 and atypical/ Nor98 scrapie are characterized by fine (reticular) deposits,
see also ;
All of the Heidenhain variants were of the methionine/ methionine type 1 molecular subtype.
http://cjdusa.blogspot.com/2009/09/co-existence-of-scrapie-prion-protein.html
see full text ;
Monday, December 14, 2009
Similarities between Forms of Sheep Scrapie and Creutzfeldt-Jakob Disease Are Encoded by Distinct Prion Types
http://nor-98.blogspot.com/2009/12/similarities-between-forms-of-sheep.html
Sunday, March 28, 2010
SPAIN BSE, Nor-98 atypical scrapie, SPORADIC CJD HIGH INCIDENT RATE >2 PER MILLION
Numero de focos de Encefalopatia Espongiforme Bovine en Espana 2009 - 1010
http://creutzfeldt-jakob-disease.blogspot.com/2010/03/spain-bse-nor-98-atypical-scrapie.html
Wednesday, February 24, 2010
Transmissible Spongiform encephalopathy (TSE) animal and human TSE in North America
14th ICID International Scientific Exchange Brochure -
Final Abstract Number: ISE.114
http://transmissiblespongiformencephalopathy.blogspot.com/
SCRAPIE, ATYPICAL, OVINE - AUSTRALIA: (WESTERN AUSTRALIA) SUSPECTED
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A ProMED-mail postProMED-mail is a program of the International Society for Infectious Diseases
[1] Date: Fri 12 Mar 2010
Source: The Australian [edited]
A West Australian sheep has been found to have signs characteristic of the fatal brain disease atypical scrapie. It comes as Australia faces growing anger from its trade partners over the Rudd government's surprise decision to extend a ban on the importation of beef from countries exposed to mad cow disease for a further 2 years.
Australia's chief veterinarian, Andy Carroll, told the ABC an indicative case of the atypical scrapie had been confirmed but said it posed no risk to human or animal health or the safety of eating meat and animal products.
Nor does atypical scrapie carry the dire trade consequences associated with classical scrapie.
Classical scrapie is in the same transmissible spongiform encephalopathies (TSE) family as BSE, better known as mad cow disease, from which humans can be fatally infected.
Dr Carroll said samples from the sheep's brain were being sent to the World Reference Laboratory in Britain.
Neither atypical scrapie nor classical scrapie has been seen in Australia before, but a sheep in New Zealand tested positive to the atypical form last year [2009].
Atypical scrapie is a relatively recently discovered disease and the common scientific view is that it occurs spontaneously or naturally in very small numbers of older sheep in countries all over the world.
[Byline: Jodie Minus]
-- Communicated by: Sabine Zentis Castleview Pedigree English Longhorns Gut Laach 52385 Nideggen Germany
****** [2] Date: Wed 10 Mar 2010 Source: ABC News (Australian Broadcasting Corporation) [edited]
Animal health authorities are testing a sheep's brain for what could be Australia's 1st case of the disease atypical scrapie.
Although not confirmed, the sheep is thought to be from Western Australia.
This type of scrapie is described as a sporadic degenerative brain condition affecting older sheep, and is not contagious.
Ed Klim, from national advisory group SafeMeat, says a 2nd round of testing is now taking place. "We've been made aware that the Australian Animal Health Laboratory is conducting further routine testing on a sheep sample," he says.
"The disease isn't considered a health risk nor should have any impact on food safety or export markets for sheep meat of live sheep."
Australia's chief veterinarian and WA's Department of Agriculture of Food are both aware of the testing but will not comment.
-- Communicated by: Terry S Singeltary Sr
[Although atypical scrapie is not yet ruled out, it is important to realize this is a type of scrapie that thus far has only tended to appear as a sporadic condition in older animals. Currently it has not been shown to follow the same genetic tendencies for propagation as the usual scrapie.
However, the atypical phenotypic appearance has been shown to be preserved on experimental passage.
Atypical scrapie was first identified in Norwegian sheep in 1998 and has subsequently been identified in many countries, as Australia may join that list. It is likely that this case will be sent to the UK for definitive conformation.
[Ref: M Simmons, T Konold, L Thurston, et al. BMC Veterinary Research 2010, 6:14 [provisional abstract available at
]
"Background ----------- "Retrospective studies have identified cases predating the initial identification of this form of scrapie, and epidemiological studies have indicated that it does not conform to the behaviour of an infectious disease, giving rise to the hypothesis that it represents spontaneous disease. However, atypical scrapie isolates have been shown to be infectious experimentally, through intracerebral inoculation in transgenic mice and sheep. [Many of the neurological diseases can be transmitted by intracerebral inoculation, which causes this moderator to approach intracerebral studies as a tool for study, but not necessarily as a direct indication of transmissibility of natural diseases. - Mod.TG]
"The 1st successful challenge of a sheep with 'field' atypical scrapie from an homologous donor sheep was reported in 2007.
"Results -------- "This study demonstrates that atypical scrapie has distinct clinical, pathological, and biochemical characteristics which are maintained on transmission and sub-passage, and which are distinct from other strains of transmissible spongiform encephalopathies in the same host genotype.
"Conclusions ------------ Atypical scrapie is consistently transmissible within AHQ homozygous sheep, and the disease phenotype is preserved on sub-passage."
Lastly, this moderator wishes to thank Terry Singletary for some of his behind the scenes work of providing citations and references for this posting. - Mod.TG]
The HealthMap/ProMED-mail interactive map of Australia is available at. - Sr.Tech.Ed.MJ]
[see also: 2009 ---- Scrapie, atypical, ovine - New Zealand (02) 20091029.3740 Scrapie, atypical, ovine - New Zealand 20090220.0714 2007 ---- Scrapie, atypical, sheep - USA (WY): 1st report 20070318.0949 2005 ---- Scrapie, atypical, ovine - Falkland Islands 20051120.3371 2004 ---- Scrapie, atypical, sheep - UK and Ireland 20041210.3274 Scrapie, atypical, sheep - UK (02) 20040409.0965 Scrapie, atypical, sheep - UK 20040408.0952 Scrapie, atypical, sheep - France: OIE 20040201.0390] ...................................sb/tg/mj/lm
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http://www.promedmail.org/pls/apex/f?p=2400:1001:3033292671016132::NO::F2400_P1001_BACK_PAGE,F2400_P1001_PUB_MAIL_ID:1010,81729
ISSN 1746-6148 Article type Research article Submission date 26 October 2009 Acceptance date 10 March 2010
Publication date 10 March 2010 Article URL http://www.biomedcentral.com/1746-6148/6/14
The natural atypical scrapie phenotype is preserved on experimental transmission and sub-passage in PRNP homologous sheep
http://www.biomedcentral.com/content/pdf/1746-6148-6-14.pdf
Friday, February 05, 2010
New Variant Creutzfelt Jakob Disease case reports United States 2010 A Review
http://vcjd.blogspot.com/2010/02/new-variant-creutzfelt-jakob-disease.html
Sunday, April 18, 2010
SCRAPIE AND ATYPICAL SCRAPIE TRANSMISSION STUDIES A REVIEW 2010
http://scrapie-usa.blogspot.com/2010/04/scrapie-and-atypical-scrapie.html
position: Post Doctoral Fellow Atypical BSE in Cattle
Closing date: December 24, 2009
Anticipated start date: January/February 2010
Employer: Canadian and OIE Reference Laboratories for BSE CFIA Lethbridge Laboratory, Lethbridge/Alberta
The Canadian and OIE reference laboratories for BSE are extensively involved in prion diseases diagnosis and research. With a recent increase in research activities and funding, the laboratory is looking to fill two post doctoral fellow positions. Both positions will be located at the Canadian Food Inspection Agency (CFIA) Lethbridge Laboratory which offers biosaftey level 3 (BSL3) and BSL2 laboratory space and is well equipped for molecular and morphologic prion research. The facility also has a BSL3 large animal housing wing and a state of the art post mortem room certified for prion work. Successful candidates will have the opportunity to visit other laboratories to cooperate in various aspects of the projects and to be trained in new techniques and acquire new skills. With a recent increase in prion disease expertise and research in Alberta and Canada, these positions will offer significant exposure to cutting edge prion science via videoconferencing, meetings, workshops and conferences. These interactions will also provide a valuable opportunity to present research findings and discuss potential future work opportunities and collaborations with other Canadian and international research groups.
Atypical BSE in Cattle
BSE has been linked to the human disease variant Creutzfeldt Jakob Disease (vCJD). The known exposure pathways for humans contracting vCJD are through the consumption of beef and beef products contaminated by the BSE agent and through blood transfusions. However, recent scientific evidence suggests that the BSE agent may play a role in the development of other forms of human prion diseases as well. These studies suggest that classical type of BSE may cause type 2 sporadic CJD and that H-type atypical BSE is connected with a familial form of CJD.
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.
Responsibilities include:
Driving research at the National and OIE BSE reference lab to ensure project milestones are met successfully. Contributing to the preparation of project progress reports. Directing technical staff working on the project. Communicating and discussing results, progress and future direction with project principle investigator(s). Communicating with collaborative project partners. Qualifications:
Successful completion of a PhD degree in an area focusing on or related to prion diseases. Extensive experience with molecular and/or morphologic techniques used in studying prion diseases and/or other protein misfolding disorders. Ability to think independently and contribute new ideas. Excellent written and oral communication skills. Ability to multitask, prioritize, and meet challenges in a timely manner. Proficiency with Microsoft Office, especially Word, PowerPoint and Excel. How to apply:
Please send your application and/or inquiry to: Dr. Stefanie Czub, DVM, Ph.D. Head, National and OIE BSE Reference Laboratory Canadian Food Inspection Agency Lethbridge Laboratory P.O. Box 640, Township Road 9-1 Lethbridge, AB, T1J 3Z4 Canada
phone: +1-403-382-5500 +1-403-382-5500 ext. 5549 email: stefanie.czub@inspection.gc.ca
Contact Info:
http://www.prionetcanada.ca/detail.aspx?menu=5&dt=293380&app=93&cat1=387&tp=20&lk=no&cat2
Wednesday, March 31, 2010
Atypical BSE in Cattle / position: Post Doctoral Fellow
http://bse-atypical.blogspot.com/2010/03/atypical-bse-in-cattle-position-post.html
14th International Congress on Infectious Diseases H-type and L-type Atypical BSE January 2010 (special pre-congress edition)
18.173 page 189
Experimental Challenge of Cattle with H-type and L-type Atypical BSE
A. Buschmann1, U. Ziegler1, M. Keller1, R. Rogers2, B. Hills3, M.H. Groschup1. 1Friedrich-Loeffler-Institut, Greifswald-Insel Riems, Germany, 2Health Canada, Bureau of Microbial Hazards, Health Products & Food Branch, Ottawa, Canada, 3Health Canada, Transmissible Spongiform Encephalopathy Secretariat, Ottawa, Canada
Background: After the detection of two novel BSE forms designated H-type and L-type atypical BSE the question of the pathogenesis and the agent distribution of these two types in cattle was fully open. From initial studies of the brain pathology, it was already known that the anatomical distribution of L-type BSE differs from that of the classical type where the obex region in the brainstem always displays the highest PrPSc concentrations. In contrast in L-type BSE cases, the thalamus and frontal cortex regions showed the highest levels of the pathological prion protein, while the obex region was only weakly involved.
Methods:We performed intracranial inoculations of cattle (five and six per group) using 10%brainstemhomogenates of the two German H- and L-type atypical BSE isolates. The animals were inoculated under narcosis and then kept in a free-ranging stable under appropriate biosafety conditions.At least one animal per group was killed and sectioned in the preclinical stage and the remaining animals were kept until they developed clinical symptoms. The animals were examined for behavioural changes every four weeks throughout the experiment following a protocol that had been established during earlier BSE pathogenesis studies with classical BSE.
Results and Discussion: All animals of both groups developed clinical symptoms and had to be euthanized within 16 months. The clinical picture differed from that of classical BSE, as the earliest signs of illness were loss of body weight and depression. However, the animals later developed hind limb ataxia and hyperesthesia predominantly and the head. Analysis of brain samples from these animals confirmed the BSE infection and the atypical Western blot profile was maintained in all animals. Samples from these animals are now being examined in order to be able to describe the pathogenesis and agent distribution for these novel BSE types. Conclusions: A pilot study using a commercially avaialble BSE rapid test ELISA revealed an essential restriction of PrPSc to the central nervous system for both atypical BSE forms. A much more detailed analysis for PrPSc and infectivity is still ongoing.
http://www.isid.org/14th_icid/
http://ww2.isid.org/Downloads/IMED2009_AbstrAuth.pdf
http://www.isid.org/publications/ICID_Archive.shtml
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.
page 114 ;
http://ww2.isid.org/Downloads/14th_ICID_ISE_Abstracts.pdf
Wednesday, February 24, 2010
Transmissible Spongiform encephalopathy (TSE) animal and human TSE in North America 14th
ICID International Scientific Exchange Brochure -
http://transmissiblespongiformencephalopathy.blogspot.com/2010/02/transmissible-spongiform-encephalopathy.html
TSE
http://transmissiblespongiformencephalopathy.blogspot.com/
TSS
Chantal Hausermann , Heinzpeter Schwermer , Anna Oevermann , Alice Nentwig , Andreas Zurbriggen , Dagmar Heim and Torsten Seuberlich
BMC Veterinary Research 2010, 6:20doi:10.1186/1746-6148-6-20
Published: 18 April 2010
Abstract (provisional)
Background
After bovine spongiform encephalopathy (BSE) emerged in European cattle livestock in 1986 a fundamental question was whether the agent established also in the small ruminants' population. In Switzerland transmissible spongiform encephalopathies (TSEs) in small ruminants have been monitored since 1990. While in the most recent TSE cases a BSE infection could be excluded, for historical cases techniques to discriminate scrapie from BSE had not been available at the time of diagnosis and thus their status remained unclear. We herein applied state-of-the-art techniques to retrospectively classify these animals and to re-analyze the affected flocks for secondary cases. These results were the basis for models, simulating the course of TSEs over a period of 70 years. The aim was to come to a statistically based overall assessment of the TSE situation in the domestic small ruminant population in Switzerland.
Results
In sum 16 TSE cases were identified in small ruminants in Switzerland since 1981, of which eight were atypical and six were classical scrapie. In two animals retrospective analysis did not allow any further classification due to the lack of appropriate tissue samples. We found no evidence for an infection with the BSE agent in the cases under investigation. In none of the affected flocks, secondary cases were identified. A Bayesian prevalence calculation resulted in most likely estimates of one case of BSE, five cases of classical scrapie and 21 cases of atypical scrapie per 100'000 small ruminants. According to our models none of the TSEs is considered to cause a broader epidemic in Switzerland. In a closed population, they are rather expected to fade out in the next decades or, in case of a sporadic origin, may remain at a very low level.
Conclusions
In summary, these data indicate that despite a significant epidemic of BSE in cattle, there is no evidence that BSE established in the small ruminant population in Switzerland. Classical and atypical scrapie both occur at a very low level and are not expected to escalate into an epidemic. In this situation the extent of TSE surveillance in small ruminants requires reevaluation based on cost-benefit analysis.
http://www.biomedcentral.com/1746-6148/6/20/abstract
Discussion
In the past 30 years 16 cases of TSE have been identified in Swiss sheep and goats. Seven cases date back to the 1990s, the decade of the highest BSE incidence in domestic cattle; it was not clear whether they were scrapie cases as assumed or rather the result of a BSE infection. Here we show now that in five of these animals the IHC labeling pattern was consistent with classical scrapie. Still in two sheep a TSE could not be confirmed by IHC. However, a definite evaluation of both cases is not feasible because either diagnostic target sites, obex for classical scrapie and BSE and cerebellar cortex for atypical scrapie, are missing or frozen unfixed material allowing proceeding to alternative tests such as ELISA or WB, is not available. The result of the present study together with previously published work on the biochemical PrPd -typing of the more recent TSE isolates detected in 2004/2005 [24] indicate no evidence for BSE in the domestic small ruminant population in Switzerland. Nevertheless, the data derived from passive surveillance need careful interpretation, because they largely depend on disease awareness and compliance with the regulations. It is therefore difficult to assess how many suspicious sheep and goats had been missed or were not reported in the past. However, based on the results of the active surveillance that in principle overcomes these limitations, it appears highly unlikely that BSE became established in the small ruminant population in Switzerland.
Classical scrapie has never been considered an important threat in Switzerland. Indeed, the surveillance data imply that it is a very rare disease. Secondary cases were not found in the present study. Moreover, all scrapie cases were geographically separated and epidemiological follow-up investigations found no relation between the affected flocks (unpublished data). Disease transmission between and within flocks therefore appears very inefficient. A factor that may account for such a situation is a
19
very low frequency of animals with classical scrapie susceptible PRNP genotypes. Unfortunately several attempts to extract genomic DNA from wax embedded tissues of the historic cases and their flock mates failed (unpublished data). However, for those of case S1/RS, DNA samples were available and more than half of them revealed a classical scrapie susceptible genotype. Moreover, in some of the affected sheep flocks (see additional file 2) and also in previous investigations it has been documented that such genotypes occur at rates ranging from approximately 30% to 60% in different domestic sheep breeds [33]. It can therefore be assumed that a proportion of the flock mates of the historic cases were indeed of susceptible genotypes. Environmental contamination is considered to substantially contribute to the persistence of classical scrapie in affected populations. There is evidence that the agent may remain infectious over years, if not decades, in the environment [38,39]. In Switzerland this factor does not appear to play an important role. This could be related to relatively small herd sizes and a low percentage of intensive farming in the Swiss small ruminant sector and differences in herd management and lambing practice compared to other countries [40].
It was rather unexpected, that only one case of classical scrapie has been identified in the 2004-2005 active surveillance program, which is considered much more efficient compared to passive surveillance alone. A possible explanation is that the prevalence of classical scrapie decreased compared to the mid 1990s when most of the other cases were identified. This could be the result of a very efficient passive surveillance and successful disease control or may be related to other yet unidentified factors that affect disease transmission. An interesting finding was that the two classical scrapie affected goats (IDs 15355 and 22614) originated from CAEV infected flocks. CAEV is closely related, if not identical, to maedi-visna virus in sheep; both belong to the genus lentivirus. There are several lines of evidence
20
indicating that lentivirus infections play a role in the pathogenesis and transmission of scrapie [41-43]. CAE has been subject to mandatory eradication policies in Switzerland since 1994 and thereupon its prevalence has been drastically reduced. This situation may at least partially explain the absence of classical scrapie in goats in the 2004/2005 active surveillance sample. Although scientifically not proven, one could also speculate that the ban on MBM in ruminant feed since 1990 might have prevented recycling not only of BSE but also of classical scrapie to sheep and goats. Finally, we cannot exclude that single cases of classical scrapie eventually result from spontaneous PrPc to PrPd conversion events and occur as a sporadic TSE similar to sporadic TSEs in humans. However, at the time being such scenarios are highly speculative.
snip...
Conclusions
In the wake of the BSE epidemic in cattle, fundamental concerns regarding a possible maintenance of the agent in the small ruminant population were raised. Based on the present study it is considered highly unlikely that the BSE agent was endemic in Swiss sheep and goats at the time when BSE in cattle faded out in 2006.
24
However, statistically we cannot exclude that single cases occurred. In addition, the prevalence of classical scrapie was calculated as very low, but atypical scrapie was found at a higher rate. Even the forecast of the prevalence of small ruminant TSEs in a simulation model for the next decades in an unlikely worst-case scenario predicted that an epidemic of either type of small ruminant TSE in Switzerland cannot be expected. In view of the high costs related to active TSE surveillance in small ruminants the design of such programs must be subject of cost-benefit analysis. If this finally results in pure passive disease surveillance schemes, their efficiency must be provided by a high disease awareness and compliance.
http://www.biomedcentral.com/content/pdf/1746-6148-6-20.pdf
> In summary, these data indicate that despite a significant epidemic of BSE in cattle
Category III: likely to present a BSE risk, even if not confirmed, or presenting a low level of confirmed BSE risk
Albania
Cyprus
Czech Republic
Estonia
Hungary
Lithuania
Poland
Slovak republic
Switzerland
http://ec.europa.eu/dgs/health_consumer/library/press/press123_en.html
BSE prions propagate as either variant CJD-like or sporadic CJD-like prion strains in transgenic mice expressing human prion protein
Emmanuel A. Asante, Jacqueline M. Linehan, Melanie Desbruslais, Susan Joiner, Ian Gowland, Andrew L. Wood, Julie Welch, Andrew F. Hill, Sarah E. Lloyd, Jonathan D.F. Wadsworth, and John Collinge1 MRC Prion Unit and Department of Neurodegenerative Disease, Institute of Neurology, University College, Queen Square, London WC1N 3BG, UK 1Corresponding author e-mail: j.collinge@prion.ucl.ac.ukReceived August 1, 2002; Revised September 24, 2002; Accepted October 17, 2002.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC136957/?tool=pubmed
CJD RISING SWITZERLAND
CJD is a predominantly sporadic disorder but can also occur as a dominantly inherited or infective condition. Only one of the 26 most recent confirmed cases was identified as carrying a disease related mutation of the PRNP gene, none had identifiable iatrogenic exposure, and none resembled variant CJD. Thus 25 of the 26 cases appear to be sporadic cases. Sporadic CJD is distributed worldwide with a reported incidence of about one in a million per year. Raised awareness of the disease in recent years could account for an increase in reported cases of CJD, although neither an increase in the average age of patients nor more frequent recognition of CJD amongst residents of nursing homes (where dementing illness is prevalent and misdiagnosis might be expected) were seen in the Swiss cases. Moreover, improved ascertainment as an explanation for the observed increase would imply levels of under-reporting in countries other than Switzerland, which appear implausible. The authors of the Lancet report suggest that the rise in cases might be due to some form of unidentified iatrogenic transmission or to exposure to a zoonotic source of infection, though cases do not resemble variant Creutzfeldt-Jakob disease (vCJD). The ongoing surveillance of CJD in Switzerland and the rest of Europe is essential to monitor the situation to see if this rise is sustained in Switzerland, and if a similar rise occurs in other countries (see http://www.eurocjd.ed.ac.uk).
http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=1921
Prion data suggest BSE link to sporadic CJD Declan Butler
Predicting the number of cases of Creutzfeldt-Jakob disease (CJD) in people as a result of transmission of bovine spongiform encephalopathy (BSE) has just got more difficult.Whereas it was thought that BSE only caused a new form of the disease called variant CJD (vCJD), a study in mice from a team led by John Collinge at University College London suggests that it may also cause a disease indistinguishable from the commonest form of classical, or 'sporadic', CJD (E.
http://www.nature.com/nature/journal/v420/n6915/full/420450a.html
IF we look at sporadic incidence of CJD in UK from 1993 to 2003, the incidence rose from 37 in 1993 to 77 in 2003. THIS seems to show an increase to me? I do not understand the statement ;
However, in the period following the first published description of vCJD in 1996, there was no increasing trend in the reported annual number of U.K. sporadic CJD deaths (52).
IF we go further and look at some of the other documented BSE countries, you will the increase of sporadic CJD there as well ;
Canada from 2 to 25
France from 35 to 108
Germany 21+ to 96
Italy 27 to 76
Switerland 8 to 18 in 2001 and 2002
http://www.eurocjd.ed.ac.uk/sporadic.htm
Switzerland sporadic CJD ;
Swiss rise in CJD raises concerns over possible BSE link [LONDON] THE LANCET
Plaque attack: Swiss patients have spongiform patterns in the brain typical of sporadic CJD. The number of people dying from Creutzfeldt-Jakob disease (CJD) has risen sharply in Switzerland -- sparking fears of a possible link with bovine spongiform encephalopathy (BSE).
BSE is thought to be the cause of a distinctive form of the brain-wasting disease known as variant CJD. The Swiss cases, in contrast, are standard 'sporadic' CJD. Each year between 1997 and 2000, no more than 11 Swiss people developed CJD. But 19 cases were reported in 2001, and seven were recorded in the first quarter of this year. This is some four times higher than the incidence elsewhere, reports a team led by Adriano Aguzzi of the University Hospital Zurich (M. Glatzel et al. Lancet 360, 139-141; 2002).
The increase could be a mere statistical blip, or it may be due to increased awareness of the disease leading to more diagnoses. More disturbing is the possibility that the cases are linked to the consumption of BSE-infected meat products -- which would mean that the BSE agent can cause two distinct forms of CJD.
Possible links between the Swiss CJD cases and BSE will now be explored by strain-typing experiments in which the disease is transmitted to mice. These tests will take at least a year to complete. "It's the best way to establish or exclude any suspected link," says Moira Bruce of the UK Institute for Animal Health's Neuropathogenesis Unit in Edinburgh.
======================================
Experiences in England and Switzerland -- two countries that discovered mad cow disease in their cattle -- have heightened concerns about the possibility some cases of sporadic CJD are due to consuming mad-cow-tainted beef. Both countries have reported increases in sporadic CJD since mad cow was first detected in British herds in 1986.
Switzerland discovered last year its CJD rate was twice that of any other country in the world. Switzerland had been seeing about eight to 11 cases per year from 1997 to 2000. Then the incidence more than doubled, to 19 cases in 2001 and 18 cases in 2002.
http://www.upi.com/view.cfm?StoryID=20030721-102924-4786r
Mouse model sheds new light on human prion disease
snip...
Professor John Collinge said We are not saying that all or even most cases of sporadic CJD are as a result of BSE exposure, but some more recent cases may be the incidence of sporadic CJD has shown an upward trend in the UK over the last decade. While most of this apparent increase may be because doctors are now more aware of CJD and better at diagnosing it, serious consideration should be given to a proportion of this rise being BSE-related. Switzerland, which has had a substantial BSE epidemic, has noted a sharp recent increase in sporadic CJD.
snip...
http://www.mrc.ac.uk/txt/index/public-interest/public-news-4/public-news_archive/public-news-archive_nov_dec_02/public-bse_and_sporadic_cjd.htm
BMC Public Health. 2009; 9: 18. Published online 2009 January 14. doi: 10.1186/1471-2458-9-18.
PMCID: PMC2637857
Copyright © 2009 Ruegger et al; licensee BioMed Central Ltd.
A case-control study of sporadic Creutzfeldt-Jakob disease in Switzerland: analysis of potential risk factors with regard to an increased CJD incidence in the years 2001–2004
Jessica Ruegger,#1 Katharina Stoeck,#2,3 Lorenz Amsler,4,5 Thomas Blaettler,2,6 Marcel Zwahlen,7 Adriano Aguzzi,2 Markus Glatzel,2,8 Klaus Hess,1 and Tobias Eckert4,9 1Department of Neurology, University Hospital Zurich, Zurich, Switzerland 2Institute of Neuropathology, University Hospital Zurich, Zurich, Switzerland 3Department of Neurology, University Hospital Hamburg-Eppendorf, Hamburg-Eppendorf, Hamburg, Germany 4Federal Office of Public Health, Bern, Switzerland 5CSL Behring, Bern, Switzerland 6Bristol-Myers Squibb, Wallingford, CT, USA 7Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland 8Institute of Neuropathology, University Hospital Hamburg-Eppendorf, Hamburg-Eppendorf, Hamburg, Germany 9Swiss Tropical Institute, Basel, Switzerland Corresponding author. #Contributed equally. Jessica Ruegger: jessica.ruegger@gmail.com ; Katharina Stoeck: kstoeck@uke.uni-hamburg.de ; Lorenz Amsler: Lorenz.Amsler@cslbehring.com ; Thomas Blaettler: thomas.blaettler@bms.com ; Marcel Zwahlen: zwahlen@ispm.unibe.ch ; Adriano Aguzzi: adriano.aguzzi@usz.ch ; Markus Glatzel: m.glatzel@uke.uni-hamburg.de ; Klaus Hess: k_h@bluewin.ch ; Tobias Eckert: tobias.eckert@bag.admin.ch
Received July 11, 2008; Accepted January 14, 2009. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
Background
In 2001, the observed annual mortality from Creutzfeldt-Jakob disease (CJD) in Switzerland increased from less than 1.5 to 2.6 per million inhabitants. An underlying cause could not be identified.
Methods
To analyse potential risk factors for sCJD in Switzerland, close relatives of 69 sCJD-patients and 224 frequency age-matched controls were interviewed in a case-control study using a standardised questionnaire. 135 potential risk factors including socio-demographics, medical history, occupation and diet were analysed by logistic regression adjusting for age, sex and education.
Results
sCJD patients were more likely to have travelled abroad, worked at an animal laboratory, undergone invasive dental treatment, orthopaedic surgery, ophthalmologic surgery after 1980, regular GP visits, taken medication regularly, and consumed kidney. No differences between patients and controls were found for residency, family history, and exposure to environmental and other dietary factors.
Conclusion
Although some factors were significantly more frequent among sCJD-cases, this study did not reveal specific explanations for the increased incidence of deaths due to sporadic CJD observed in Switzerland since 2001. Results have to be interpreted with caution due to multiple testing and possible recall bias in association with a long incubation period. The most plausible reason for the increase in Swiss sCJD cases after 2000 is an improved case ascertainment. Therefore, underreporting of cases might well have occurred before the year 2001, and the "real" yearly incidence of sCJD might not be lower than, but rather above 2 per million inhabitants.
snip...
Discussion
This study evaluated a wide range of possible risk factors as risk factors for sCJD-cases observed in Switzerland between 2001 and 2004. If some of the positively associated risk factors were truly causal and would have become more frequent in recent years and decades, then they might have contributed to the increase in sCJD-cases in Switzerland. Although some analysed factors were significantly more frequent in the group of sCJD patients, the results of this case-control study have not produced unequivocal evidence for specific environmental or iatrogenic risk factors for sCJD, and thus could not reveal a specific explanation for the increased incidence. In interpreting the results, one has to bear in mind that with a significance level set at 5%, on average one in twenty results will be significant, by chance alone.
***
Starting with the hypothesis of a zoonotic cause similar to the development of vCJD by consumption of BSE-contaminated material, the present study does not demonstrate a clearly increased risk for sCJD with respect to dietary habits. Although previous studies revealed that consumption of several meat products was increased in sCJD cases compared to controls,[26,27] no such clear differences for any of the twenty diet-related exposures were found in our as well as in earlier studies. [28-30] Consistent with previous studies, no significant differences between sCJD patients and controls was found with respect to occupational exposures, including work in animal farming or in the meat industry in the present study. One exception was work in an animal laboratory. [27-31] Some findings of earlier studies which revealed higher frequencies of sCJD among butchers,[32] among those exposed to leather products, to fertiliser consisting of hoofs and horns,[27] and to farm-stays for any length of time,[31] could not be reproduced in this study. Contrary to the hypothesis of a zoonotic cause, earlier studies did not link pet animals possession to increased risk. [27-30] Patients in this study even less often owned cats or pet rodents. Travelling abroad was significantly more frequent in sCJD patients. Controls, however, travelled more frequently to the United Kingdom where risk for vCJD was elevated and to tropical destinations where some infectious diseases are more prevalent than in Switzerland. No differences in age, sex, place of birth and living or family history of dementia were found. These results are consistent with data from previous studies.[26,28,29] In contrast to earlier studies, sCJD-patients in our study had completed less years of education.[26,28] Only 45% of the cases had ten or more school years, whereas this figure was at 71% among the controls. These findings might be due to recall bias which can occur when interviewing proxy persons. However, another neurodegenerative disease, Alzheimer's disease has been shown to be observed more frequently in persons with lower levels of education.[33]
***
Concerning the hypothesis of an iatrogenic cause, sCJD cases in this study significantly more often had undergone orthopaedic and ophthalmologic surgery, invasive dental treatment as well as regular medical treatment. In previous studies, physical injuries and stressful life events such as surgical procedures,[23,28,30,31,34,35] and work in a medical profession[32] have been found to constitute a risk factor for sCJD. In particular, head surgery and trauma to other body parts were identified.[36] In contrast to the present study, however, orthopaedic surgery and invasive dental treatments per se were not associated with an elevated risk for sCJD before.[27,28,31,36] One could speculate that the use of surgical instruments as well as a potentially higher rate of blood transfusions in orthopaedic surgery may explain these findings. Receiving blood transfusions has been demonstrated to be a potential route of vCJD transmission.[20] The development of vCJD involves a peripheral route of prion transmission to the CNS. In sCJD, however, the disease most likely starts in the brain, even though recently, prions have been detected in peripheral organs such as the spleen and skeletal muscles of sCJD patients.[37] Blood transfusions, however, were not associated with sCJD in the present study. Interestingly, blood donation was less frequently observed in sCJD patients than in controls. Correspondingly, neither receiving blood transfusions nor blood donation was identified as a risk factor for sCJD in previous studies.[23,26,38,39] Cigarette smoking was more frequent in controls (29%) than in sCJD patients (13%) or in the general population, a finding which points to some bias in the selection of controls. A previous analysis did not find any association with smoking.[26]
***
Recently, the heightened incidence of sCJD in Switzerland was found to be associated with a shift in clinicopathological profiles, in that sporadic CJD patients from the cohort with elevated sporadic CJD incidence presented with a higher frequency of rare sporadic CJD-subtypes (MV2, VV2). Patients of these subtypes were significantly older and showed a skewed male/female ratio when compared to patients of identical sporadic CJD-types or to patients from the 1996–2000 cohort.[22]
The third hypothesis to explain the increase in annual mortality rates from sCJD in Switzerland between 2001 and 2004 is a better case ascertainment. Over recent years in Europe, as a general tendency incidences have been rising, however not to such extent as in Switzerland. Given that our results do not support strong evidence for the hypotheses of a zoonotic or iatrogenic cause, ascertainment bias due to a heightened perception and awareness of the disease in physicians must be regarded as the most likely cause for the observed increase. One factor that might be jointly responsible for this increase might be altered reporting requirements in 1999. Since that year all suspected cases in Switzerland had to be reported. In this respect, also the role of chance must be considered, as it is possible that the observed increase of Swiss sCJD-deaths was due to random fluctuation. The rise in annual mortality rate from the years before 2000 to the period 2001–2004, however, was statistically significant, and therefore, chance must be considered a less likely explanation. In the most recent years, the observed incidence in sCJD deaths (2005: 10; 2006: 13, 2007: 15) dropped to levels just slightly above those before 2000. When recent incidence data until 2007 are included, however, the rise in the annual mortality rate after 2001 was still significant. The sudden increase in 2001 and the slow decrease afterwards are well in line with the media coverage of the CJD topic in the respective years.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2637857/?tool=pubmed
Finally the authors consider the possibility that CJD in Switzerland is related to a prion epizootic, and pay considerable attention to this possibility since between 1995 and 1998, Switzerland reported a larger incidence of BSE than did all other continental European countries (415 cases between 1990 and 2002). Exposure to BSE-infected products might have taken place mainly before high-risk bovine food products were banned from the human food chain in 1990. However, BSE is thought to cause variant CJD [abbreviated as vCJD or CJD (new var.) in ProMED-mail] rather than sporadic CJD, yet all evidence indicates that none of the Swiss cases fulfill the diagnostic criteria of vCJD. Swiss CJD could be related to BSE only if the strain of Swiss BSE prion differs from the strain of BSE prevalent in the UK. Available data, though limited, suggest that this is not the case.
At present there is no evidence that the Swiss CJD cases might result from transmission of BSE to people after one or more serial passages through species other than cattle. Scrapie is exceedingly rare in Switzerland: only 7 cases have been reported in the past 10 years. Chronic wasting disease of deer has not been reported in Europe, although surveillance data on transmissible spongiform encephalopathies in European game are incomplete.
All recognized clinical and molecular markers combine to indicate that none of the Swiss patients developed vCJD. The authors conclude that the elucidation of the underlying chain of events is a national research priority, and may uncover previously unrecognized modes of prion infection and transmission. It remains to be seen whether this increase in the incidence of CJD in Switzerland will be sustained, or whether it represent a statistical anomaly. According to Will RG, et al. (Ann Neurol 1998; 43: 763-767) there was a doubling in the annual death rates for sporadic CJD in the United Kingdom between the 1980s and the 1990s, and similar increases in the apparent death rates for sporadic Creutzfeldt-Jakob disease had occurred in other European countries, attributable to improvement in diagnosis. - Mod.CP].................as/mpp/cp/mpp
http://www.promedmail.org/pls/otn/f?p=2400:1202:307098::NO::F2400_P1202_CHECK_DISPLAY,F2400_P1202_PUB_MAIL_ID:X,18755
Saturday, February 14, 2009
A case-control study of sporadic Creutzfeldt-Jakob disease in Switzerland: analysis of potential risk factors with regard to an increased CJD incidence in the years 2001–2004
http://creutzfeldt-jakob-disease.blogspot.com/2009/02/case-control-study-of-sporadic.html
Monday, December 14, 2009
Similarities between Forms of Sheep Scrapie and Creutzfeldt-Jakob Disease Are Encoded by Distinct Prion Types
hmmm, this is getting interesting now...
Sporadic CJD type 1 and atypical/ Nor98 scrapie are characterized by fine (reticular) deposits,
see also ;
All of the Heidenhain variants were of the methionine/ methionine type 1 molecular subtype.
http://cjdusa.blogspot.com/2009/09/co-existence-of-scrapie-prion-protein.html
see full text ;
Monday, December 14, 2009
Similarities between Forms of Sheep Scrapie and Creutzfeldt-Jakob Disease Are Encoded by Distinct Prion Types
http://nor-98.blogspot.com/2009/12/similarities-between-forms-of-sheep.html
Sunday, March 28, 2010
SPAIN BSE, Nor-98 atypical scrapie, SPORADIC CJD HIGH INCIDENT RATE >2 PER MILLION
Numero de focos de Encefalopatia Espongiforme Bovine en Espana 2009 - 1010
http://creutzfeldt-jakob-disease.blogspot.com/2010/03/spain-bse-nor-98-atypical-scrapie.html
Wednesday, February 24, 2010
Transmissible Spongiform encephalopathy (TSE) animal and human TSE in North America
14th ICID International Scientific Exchange Brochure -
Final Abstract Number: ISE.114
http://transmissiblespongiformencephalopathy.blogspot.com/
SCRAPIE, ATYPICAL, OVINE - AUSTRALIA: (WESTERN AUSTRALIA) SUSPECTED
*******************************************************************
A ProMED-mail post
[1] Date: Fri 12 Mar 2010
Source: The Australian [edited]
A West Australian sheep has been found to have signs characteristic of the fatal brain disease atypical scrapie. It comes as Australia faces growing anger from its trade partners over the Rudd government's surprise decision to extend a ban on the importation of beef from countries exposed to mad cow disease for a further 2 years.
Australia's chief veterinarian, Andy Carroll, told the ABC an indicative case of the atypical scrapie had been confirmed but said it posed no risk to human or animal health or the safety of eating meat and animal products.
Nor does atypical scrapie carry the dire trade consequences associated with classical scrapie.
Classical scrapie is in the same transmissible spongiform encephalopathies (TSE) family as BSE, better known as mad cow disease, from which humans can be fatally infected.
Dr Carroll said samples from the sheep's brain were being sent to the World Reference Laboratory in Britain.
Neither atypical scrapie nor classical scrapie has been seen in Australia before, but a sheep in New Zealand tested positive to the atypical form last year [2009].
Atypical scrapie is a relatively recently discovered disease and the common scientific view is that it occurs spontaneously or naturally in very small numbers of older sheep in countries all over the world.
[Byline: Jodie Minus]
-- Communicated by: Sabine Zentis Castleview Pedigree English Longhorns Gut Laach 52385 Nideggen Germany
****** [2] Date: Wed 10 Mar 2010 Source: ABC News (Australian Broadcasting Corporation) [edited]
Animal health authorities are testing a sheep's brain for what could be Australia's 1st case of the disease atypical scrapie.
Although not confirmed, the sheep is thought to be from Western Australia.
This type of scrapie is described as a sporadic degenerative brain condition affecting older sheep, and is not contagious.
Ed Klim, from national advisory group SafeMeat, says a 2nd round of testing is now taking place. "We've been made aware that the Australian Animal Health Laboratory is conducting further routine testing on a sheep sample," he says.
"The disease isn't considered a health risk nor should have any impact on food safety or export markets for sheep meat of live sheep."
Australia's chief veterinarian and WA's Department of Agriculture of Food are both aware of the testing but will not comment.
-- Communicated by: Terry S Singeltary Sr
[Although atypical scrapie is not yet ruled out, it is important to realize this is a type of scrapie that thus far has only tended to appear as a sporadic condition in older animals. Currently it has not been shown to follow the same genetic tendencies for propagation as the usual scrapie.
However, the atypical phenotypic appearance has been shown to be preserved on experimental passage.
Atypical scrapie was first identified in Norwegian sheep in 1998 and has subsequently been identified in many countries, as Australia may join that list. It is likely that this case will be sent to the UK for definitive conformation.
[Ref: M Simmons, T Konold, L Thurston, et al. BMC Veterinary Research 2010, 6:14 [provisional abstract available at
"Background ----------- "Retrospective studies have identified cases predating the initial identification of this form of scrapie, and epidemiological studies have indicated that it does not conform to the behaviour of an infectious disease, giving rise to the hypothesis that it represents spontaneous disease. However, atypical scrapie isolates have been shown to be infectious experimentally, through intracerebral inoculation in transgenic mice and sheep. [Many of the neurological diseases can be transmitted by intracerebral inoculation, which causes this moderator to approach intracerebral studies as a tool for study, but not necessarily as a direct indication of transmissibility of natural diseases. - Mod.TG]
"The 1st successful challenge of a sheep with 'field' atypical scrapie from an homologous donor sheep was reported in 2007.
"Results -------- "This study demonstrates that atypical scrapie has distinct clinical, pathological, and biochemical characteristics which are maintained on transmission and sub-passage, and which are distinct from other strains of transmissible spongiform encephalopathies in the same host genotype.
"Conclusions ------------ Atypical scrapie is consistently transmissible within AHQ homozygous sheep, and the disease phenotype is preserved on sub-passage."
Lastly, this moderator wishes to thank Terry Singletary for some of his behind the scenes work of providing citations and references for this posting. - Mod.TG]
The HealthMap/ProMED-mail interactive map of Australia is available at
[see also: 2009 ---- Scrapie, atypical, ovine - New Zealand (02) 20091029.3740 Scrapie, atypical, ovine - New Zealand 20090220.0714 2007 ---- Scrapie, atypical, sheep - USA (WY): 1st report 20070318.0949 2005 ---- Scrapie, atypical, ovine - Falkland Islands 20051120.3371 2004 ---- Scrapie, atypical, sheep - UK and Ireland 20041210.3274 Scrapie, atypical, sheep - UK (02) 20040409.0965 Scrapie, atypical, sheep - UK 20040408.0952 Scrapie, atypical, sheep - France: OIE 20040201.0390] ...................................sb/tg/mj/lm
*#################################################
http://www.promedmail.org/pls/apex/f?p=2400:1001:3033292671016132::NO::F2400_P1001_BACK_PAGE,F2400_P1001_PUB_MAIL_ID:1010,81729
ISSN 1746-6148 Article type Research article Submission date 26 October 2009 Acceptance date 10 March 2010
Publication date 10 March 2010 Article URL http://www.biomedcentral.com/1746-6148/6/14
The natural atypical scrapie phenotype is preserved on experimental transmission and sub-passage in PRNP homologous sheep
http://www.biomedcentral.com/content/pdf/1746-6148-6-14.pdf
Friday, February 05, 2010
New Variant Creutzfelt Jakob Disease case reports United States 2010 A Review
http://vcjd.blogspot.com/2010/02/new-variant-creutzfelt-jakob-disease.html
Sunday, April 18, 2010
SCRAPIE AND ATYPICAL SCRAPIE TRANSMISSION STUDIES A REVIEW 2010
http://scrapie-usa.blogspot.com/2010/04/scrapie-and-atypical-scrapie.html
position: Post Doctoral Fellow Atypical BSE in Cattle
Closing date: December 24, 2009
Anticipated start date: January/February 2010
Employer: Canadian and OIE Reference Laboratories for BSE CFIA Lethbridge Laboratory, Lethbridge/Alberta
The Canadian and OIE reference laboratories for BSE are extensively involved in prion diseases diagnosis and research. With a recent increase in research activities and funding, the laboratory is looking to fill two post doctoral fellow positions. Both positions will be located at the Canadian Food Inspection Agency (CFIA) Lethbridge Laboratory which offers biosaftey level 3 (BSL3) and BSL2 laboratory space and is well equipped for molecular and morphologic prion research. The facility also has a BSL3 large animal housing wing and a state of the art post mortem room certified for prion work. Successful candidates will have the opportunity to visit other laboratories to cooperate in various aspects of the projects and to be trained in new techniques and acquire new skills. With a recent increase in prion disease expertise and research in Alberta and Canada, these positions will offer significant exposure to cutting edge prion science via videoconferencing, meetings, workshops and conferences. These interactions will also provide a valuable opportunity to present research findings and discuss potential future work opportunities and collaborations with other Canadian and international research groups.
Atypical BSE in Cattle
BSE has been linked to the human disease variant Creutzfeldt Jakob Disease (vCJD). The known exposure pathways for humans contracting vCJD are through the consumption of beef and beef products contaminated by the BSE agent and through blood transfusions. However, recent scientific evidence suggests that the BSE agent may play a role in the development of other forms of human prion diseases as well. These studies suggest that classical type of BSE may cause type 2 sporadic CJD and that H-type atypical BSE is connected with a familial form of CJD.
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.
Responsibilities include:
Driving research at the National and OIE BSE reference lab to ensure project milestones are met successfully. Contributing to the preparation of project progress reports. Directing technical staff working on the project. Communicating and discussing results, progress and future direction with project principle investigator(s). Communicating with collaborative project partners. Qualifications:
Successful completion of a PhD degree in an area focusing on or related to prion diseases. Extensive experience with molecular and/or morphologic techniques used in studying prion diseases and/or other protein misfolding disorders. Ability to think independently and contribute new ideas. Excellent written and oral communication skills. Ability to multitask, prioritize, and meet challenges in a timely manner. Proficiency with Microsoft Office, especially Word, PowerPoint and Excel. How to apply:
Please send your application and/or inquiry to: Dr. Stefanie Czub, DVM, Ph.D. Head, National and OIE BSE Reference Laboratory Canadian Food Inspection Agency Lethbridge Laboratory P.O. Box 640, Township Road 9-1 Lethbridge, AB, T1J 3Z4 Canada
phone: +1-403-382-5500 +1-403-382-5500 ext. 5549 email: stefanie.czub@inspection.gc.ca
Contact Info:
http://www.prionetcanada.ca/detail.aspx?menu=5&dt=293380&app=93&cat1=387&tp=20&lk=no&cat2
Wednesday, March 31, 2010
Atypical BSE in Cattle / position: Post Doctoral Fellow
http://bse-atypical.blogspot.com/2010/03/atypical-bse-in-cattle-position-post.html
14th International Congress on Infectious Diseases H-type and L-type Atypical BSE January 2010 (special pre-congress edition)
18.173 page 189
Experimental Challenge of Cattle with H-type and L-type Atypical BSE
A. Buschmann1, U. Ziegler1, M. Keller1, R. Rogers2, B. Hills3, M.H. Groschup1. 1Friedrich-Loeffler-Institut, Greifswald-Insel Riems, Germany, 2Health Canada, Bureau of Microbial Hazards, Health Products & Food Branch, Ottawa, Canada, 3Health Canada, Transmissible Spongiform Encephalopathy Secretariat, Ottawa, Canada
Background: After the detection of two novel BSE forms designated H-type and L-type atypical BSE the question of the pathogenesis and the agent distribution of these two types in cattle was fully open. From initial studies of the brain pathology, it was already known that the anatomical distribution of L-type BSE differs from that of the classical type where the obex region in the brainstem always displays the highest PrPSc concentrations. In contrast in L-type BSE cases, the thalamus and frontal cortex regions showed the highest levels of the pathological prion protein, while the obex region was only weakly involved.
Methods:We performed intracranial inoculations of cattle (five and six per group) using 10%brainstemhomogenates of the two German H- and L-type atypical BSE isolates. The animals were inoculated under narcosis and then kept in a free-ranging stable under appropriate biosafety conditions.At least one animal per group was killed and sectioned in the preclinical stage and the remaining animals were kept until they developed clinical symptoms. The animals were examined for behavioural changes every four weeks throughout the experiment following a protocol that had been established during earlier BSE pathogenesis studies with classical BSE.
Results and Discussion: All animals of both groups developed clinical symptoms and had to be euthanized within 16 months. The clinical picture differed from that of classical BSE, as the earliest signs of illness were loss of body weight and depression. However, the animals later developed hind limb ataxia and hyperesthesia predominantly and the head. Analysis of brain samples from these animals confirmed the BSE infection and the atypical Western blot profile was maintained in all animals. Samples from these animals are now being examined in order to be able to describe the pathogenesis and agent distribution for these novel BSE types. Conclusions: A pilot study using a commercially avaialble BSE rapid test ELISA revealed an essential restriction of PrPSc to the central nervous system for both atypical BSE forms. A much more detailed analysis for PrPSc and infectivity is still ongoing.
http://www.isid.org/14th_icid/
http://ww2.isid.org/Downloads/IMED2009_AbstrAuth.pdf
http://www.isid.org/publications/ICID_Archive.shtml
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.
page 114 ;
http://ww2.isid.org/Downloads/14th_ICID_ISE_Abstracts.pdf
Wednesday, February 24, 2010
Transmissible Spongiform encephalopathy (TSE) animal and human TSE in North America 14th
ICID International Scientific Exchange Brochure -
http://transmissiblespongiformencephalopathy.blogspot.com/2010/02/transmissible-spongiform-encephalopathy.html
TSE
http://transmissiblespongiformencephalopathy.blogspot.com/
TSS
Labels: atypical bse, bse, cjd, small ruminants, Switzerland
posted by Terry S. Singeltary Sr. at
2:31 PM
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