EFSA Journal 2013;11(2):3119 [46 pp.]. doi:10.2903/j.efsa.2013.3119
European Food Safety AuthorityAcknowledgment Contact
Type: Scientific Report of EFSA On request from: European Free Trade Association (EFTA) Surveillance Authority Question number: EFSA-Q-2012-00577 Approved: 20 February 2013 Published: 25 February 2013 Affiliation: European Food Safety Authority (EFSA) Parma Italy
This Scientific Report of EFSA provides scientific and technical assistance to the European Free Trade Association (EFTA) Surveillance Authority in evaluating i) if the Norwegian continuous use of fishmeal in feed for ruminants until 30 April 2010 has had an impact on the overall risk of BSE in the country; and ii) if a proposed Norwegian revised annual monitoring programme for BSE allows the detection of BSE with a yearly design prevalence of at least one case per 100,000 in the adult population at a confidence level of 95%. Data related to the implementation of the Norwegian feed ban were collected and assessed. The Cattle TSE Monitoring Model (C-TSEMM) was used in order to answer the second term of reference of the mandate received. It is concluded that the use of fishmeal in feed for ruminants might have had a potential impact on the risk of cattle exposure to BSE in Norway. While it is not possible to quantitatively assess this risk, the lack of detection of BSE cases by the Norwegian monitoring system (in spite of its sensitivity limits) suggests that BSE has not significantly spread in the Norwegian cattle population. The proposed revised Norwegian BSE monitoring regime would not be able to meet a yearly design prevalence of at least one case per 100,000 in the adult cattle population at a confidence level of 95%. Moreover, in statistical terms it is not feasible for Norway to achieve the requested design prevalence. It is furthermore highlighted that passing from a sample-based to an exhaustive monitoring scheme (i.e. testing all animals over a certain age that are slaughtered or dead) would provide the most sensitive BSE surveillance system currently possible.
© European Food Safety Authority, 2013
Following a request from the European Free Trade Association (EFTA) Surveillance Authority, the European Food Safety Authority (EFSA) was asked to provide scientific and technical assistance on a revision of the Norwegian annual monitoring programme for Bovine Spongiform Encephalopathy (BSE). The current Norwegian monitoring programme for BSE is based on a specific adaptation of the Agreement on the European Economic Area (EEA) to Regulation (EC) No 999/2001, allowing Norway to test a random sample of 10,000 healthy slaughtered cattle over 30 months of age per year. The Norwegian legislation is currently in line with the European Union’s (EU)5 one as regards to the feedban. However, the use of fishmeal for ruminants was legally allowed in Norway until 30 April 2010. Within this context, and taking into consideration the animal age limits set in Commission Decision 2009/719/EC (72 and 48 months of age, respectively, for healthy slaughtered and at risk animals), Norway requested to the EFTA Surveillance Authority the agreement for a revised annual monitoring programme for BSE prescribing i) the testing of a random sample of 2,000 healthy slaughtered cattle over 72 months of age per year, ii) the testing of all at-risk cattle above 48 months of age and iii) the mandatory notification and examination of any animal clinically suspected of being infected by a TSE. EFTA Surveillance Authority asked EFSA: i) to undertake an assessment of whether Norway’s continuous use of fishmeal in feed for ruminants until 30 April 2010 has had an impact on the overall risk of BSE in the country; and ii) to evaluate whether the design of the proposed annual regime of 2,000 randomly selected samples in the subpopulation of healthy slaughtered animals over 72 months of age allows the detection of BSE with a yearly design prevalence of at least one case per 100,000 in the adult population at a confidence level of 95% in Norway. In case Norway’s proposed regime would fail meeting this criterion, EFSA was requested to propose a minimum annual sample size in the subpopulation of healthy slaughtered animals over 72 months of age allowing to reach the proposed criterion. Data related to the implementation of the Norwegian feed ban were collected and assessed. In Norway the only way by which fishmeal could have represented a risk for BSE infection in ruminants was due to the potential cross-contamination with infected Meat and Bone Meal (MBM). The monitoring of ruminant feed and fishmeal for the presence of MBM in Norway did not give rise to positive results. However, considering the number of tests and the total amount of terrestrial animal feed and fishmeal produced and used in Norway the significance of these results is probably limited. Moreover, according to the reports of the missions carried out by the EFTA Surveillance Authority in Norway there were insufficient measures in place to prevent the potential for cross-contamination of fishmeal with MBM. The results of the BSE monitoring system carried out during the period 2001 – 2011 were considered. Overall 200,165 BSE screening tests were performed in Norway with no positive results. The lack of detection of BSE cases by the Norwegian monitoring system (in spite of its sensitivity limits) suggests that BSE has not significantly spread in the Norwegian cattle population. It was then concluded that the use of fishmeal in feed for ruminants might have had a potential impact on the risk of cattle exposure to BSE in Norway. However, the lack of detection of BSE cases by the Norwegian monitoring system suggests that BSE has not significantly spread in the Norwegian cattle population. The Cattle TSE Monitoring Model (C-TSEMM) was used in order to answer the second term of reference of the mandate. According to C-TSEMM the proposed revised Norwegian BSE monitoring regime would not be able to meet a yearly design prevalence of at least one case per 100,000 in the adult cattle population at a confidence level of 95% in Norway. Moreover, the results of the model indicate that in statistical terms it is not feasible for Norway to achieve the proposed design prevalence. The results of C-TSEMM have to be interpreted in the light of its assumptions, uncertainties and limitations. However, they can be considered to be an overestimation of what is achievable by the Norwegian regimes considered. It is furthermore highlighted that passing from a sample-based to an exhaustive monitoring scheme (i.e. testing all animals over a certain age that are slaughtered or dead) would provide the most sensitive BSE surveillance system currently possible.
The use of fishmeal in feed for ruminants might have had a potential impact on the risk of cattle exposure to BSE in Norway. While it is not possible to quantitatively assess this risk, the lack of detection of BSE cases by the Norwegian monitoring system (in spite of its sensitivity limits) suggests that BSE has not significantly spread in the Norwegian cattle population. According to the model applied (C-TSEMM): – the proposed revised Norwegian BSE monitoring regime would not be able to meet a yearly design prevalence of at least one case per 100,000 in the adult cattle population at a confidence level of 95% in Norway; and – even in a scenario in which all healthy slaughtered and all at risk cattle above 72 and 48 months respectively would be tested for BSE, in statistical terms it is not feasible to achieve the design prevalence of one case per 100,000 in the adult cattle population at a confidence level of 95% in Norway. The results of C-TSEMM have to be interpreted in the light of its assumptions, uncertainties and limitations. However, they can be considered to be an overestimation of what is achievable by the Norwegian regimes considered. Passing from a sample-based to an exhaustive monitoring scheme (i.e. testing all animals over a certain age that are slaughtered or dead) would provide the most sensitive BSE surveillance system currently possible.
BSE, Norway, monitoring, revision, design prevalence
Scientific Report of the European Food Safety Authority on the Assessment of the Geographical BSE Risk (GBR) of Norway
European Food Safety Authority
Type: Scientific Report of EFSA Question number: EFSA-Q-2003-083F Approved: 01 July 2004 Published: 20 August 2004 Last updated: 08 September 2004. This version replaces the previous one/s.
The European Food Safety Authority and its Scientific Expert Working Group on the Assessment of the Geographical Bovine Spongiform Encephalopathy ( BSE) Risk (GBR) were asked by the European Commission (EC) to provide an up-to-date scientific report on the GBR in Norway, i.e. the likelihood of the presence of one or more cattle being infected with BSE, pre-clinically as well as clinically, in Norway. This scientific report addresses the GBR of Norway as assessed in 2004 based on data covering the period 1980-2003.
Between 1980 and 1990, an extremely unstable system was exposed to a negligible/very low challenge. Between 1991 and 1999, the stability of the system increased to very unstable and then to unstable in 2000, while the challenge increased to moderate and subsequently decreased to negligible in 1996. Under such low/intermediate levels of risk (as judged by challenge/stability alone), the fact that no BSE case was detected by the very extensive surveillance carried out in Norway since 2001, makes the possibility that BSE-infectivity could have been recycled and amplified unlikely although it cannot be excluded.
EFSA concludes that the current geographical BSE-risk (GBR) level is II, as it is unlikely but can not be excluded that domestic cattle are (clinically or pre-clinically) infected with the BSE-agent. The Norwegian BSE/cattle system is now regarded to be very stable. This implies that the probability of cattle to become newly infected with the BSE-agent is very low. Assuming that measures in place continue to be appropriately implemented the GBR will decrease over time at the rate at which already infected animals leave the system. If the measures in place are effectively implemented, the import of live animals cannot increase the risk because the infectivity that could theoretically be harbored by them would not reach domestic cattle.
Since recent improvements in the safety of Meat and Bone Meal (MBM) production in many countries or significant recent reductions in the incidence of BSE have not been taken into account for the assessment of the external challenge in the present report, the external challenge assessed after 2001 could be overestimated and is the worst case assumption. However, all current GBR conclusions are not dependent on these assumptions in any of the countries assessed. For future assessments and when the impact of the production, surveillance and true incidence changes has been fully quantified, these developments should be taken into account. Keywords
Scientific Report of the European Food Safety Authority on the Assessment of the Geographical BSE Risk (GBR) of Norway
5. CONCLUSION ON THE GEOGRAPHICAL BSE-RISK
5.1 The current GBR as function of the past stability and challenge
• The current geographical BSE-risk (GBR) level is II, i.e. it is unlikely but can not be excluded that domestic cattle are (clinically or pre-clinically) infected with the BSE-agent.
• This assessment deviates from the previous assessment (SSC opinion, 2000) because at that time several exporting countries were not considered a potential risk.
5.2 The expected development of the GBR as a function of the past and present stability and challenge
• The Norway BSE/cattle system is now regarded to be very stable. This implies that the probability of cattle to become newly infected with the BSE-agent is very low. Assuming that measures in place continue to be appropriately implemented the GBR will decrease over time at the rate at which already infected animals leave the system.
• If the measures in place are effectively implemented, the import of live animals cannot increase the risk because the infectivity that could theoretically be harboured by them would not reach domestic cattle.
• Since recent improvements in the safety of MBM production in many countries or significant recent reductions in the incidence of BSE have not been taken into account for the assessment of the external challenge in the present report, the external challenge assessed after 2001 could be overestimated and is the worst case assumption. However, all current GBR conclusions are not dependent on these assumptions in any of the countries assessed. For future assessments and when the impact of the production, surveillance and true incidence changes has been fully quantified, these developments should be taken into account.
Report on the assessment of the Geographical BSE-risk of NORWAY July 2000
OVERALL ASSESSMENT The current geographical BSE-risk (GBR) of Norway is level I, i.e. it is highly unlikely that domestic cattle are infected (clinically or pre-clinically) with the BSE agent.
Note: This assessment leading to GBR level I is mainly based on the fact that Norway was not exposed to significant external challenges before 1995 when the system became stable.
Should this be proven wrong, a GBR level II would have to be assumed.
Annual Reports 2011
The surveillance and control programme for scrapie in Norway 2011
Sviland Ståle, Benestad Lafond Sylvie, Eikenæs Olav, Norström Madelaine
In 2011, Nor98 scrapie was diagnosed in 6 sheep coming from 6 different flocks.
Scrapie was first diagnosed in indigenous Norwegian sheep in 1981. Increasing numbers of scrapieinfected flocks were identified in the 1990s, culminating with 31 detected flocks in 1996 (Figure 1). By the end of 2009, scrapie had been diagnosed in a total of 148 sheep flocks and one goat herd (1). Scrapie has been a notifiable disease in Norway since 1965, and control measures have involved destruction of all sheep in affected flocks and in close contact flocks until 2004. The Norwegian scrapie surveillance and control programme was launched in 1997 (2). In 1998 a new type of scrapie, Nor98 scrapie, was identified in Norway. The diagnosis of Nor98 scrapie is verified by Western blot. Nor98 scrapie differs from classical scrapie in several aspects, including the Western blot profile, the distribution of protease resistant prion protein (PrPSc) in the brain, and absence of detectable PrPSc in lymphoid tissues (3). The main clinical sign observed in Nor98 scrapie cases has been ataxia. The PrP genotype distribution among Nor98 scrapie cases differs markedly from that of the previous cases with classical scrapie (4). The Norwegian Food Safety Authority is responsible for carrying out the surveillance and control programme for scrapie. The samples are collected at the abattoirs or in the herds by inspectors from the Norwegian Food Safety Authority. The Norwegian Food Safety Authority also carries out inspections of sheep flocks and goat herds, all of which should be inspected every second or third year. The Norwegian Veterinary Institute is performing the laboratory examinations and the reporting of the results.
Materials and methods
In 2011, the surveillance programme was performed according to the European Union Regulations,
Regulation (EC) No. 999/2001 Annex III, with amendments and included examination of the following categories of small ruminants:
* all small ruminants with clinical signs consistent with scrapie, irrespective of age
* 10,000 sheep older than 18 months, which had died or been killed on the farm, but not
slaughtered for human consumption (fallen stock)
* 10,000 randomly sampled healthy sheep older than 18 months slaughtered for human consumption
* 500 goats older than 18 months which had died or been killed on the farm, but not slaughtered for
human consumption (fallen stock)
The classical scrapie and Nor98 scrapie prevalences in the fallen stock and abattoir populations were estimated assuming an exact binominal distribution.
Nor98 scrapie was diagnosed in 6 sheep from 6 flocks. One Nor98 scrapie case was identified in fallen stock, five cases were apparently healthy animals slaughtered for human consumption (Table 1).
The individual age and breed were registered, and the prion protein genotype examined for all six scrapie cases (Table 2). Four sheep had PrP genotypes with at least one allele with polymorphisms at codon 141 (AF141RQ) or 154 (AHQ), whereas two sheep had the PrP genotype ARR/ARR.
In total, 13,486 samples from sheep were received. Of these, 13 (0.09%) samples were unsuitable for examination. The numbers of animals examined within each category are presented in Table 1. The prevalence of Nor98 scrapie in the fallen stock of sheep was estimated to 0.02% (0.0-0.12%), (95% confidence interval [CI]) (Figure 2), and the prevalence of Nor98 scrapie in sheep slaughtered for human consumption was estimated to 0.06% (0.0-0.13%), (95% CI) (Figure 3).
For 135 (1.0%) samples (111 healthy slaughtered, 22fallen stock and one from the ante mortem control), the flock of origin was not reported. In the event of a positive sample from slaughtered animals, the flock identity could be traced using the carcass number. The remaining 13,352 samples were collected from carcasses originating in 5,596 different sheep flocks. The mean number of animals tested per flock was 2.3 (range 1-29), flocks eradicated due to scrapie are excluded. From 1,746 flocks more than two samples were tested. The samples were obtained throughout the year, with approximately 26% of the samples collected in September and October, which is the main slaughtering season for sheep in Norway.
PrP genotyping was performed on 639 sheep randomly sampled from the healthy slaughtered population examined in Harstad. The PrP genotypes are grouped in accordance with the British National Scrapie Plan (NSP) (Table 3).
Scrapie was not detected in any goat in 2011.
In total, 390 samples from goats were received. In six of these the flock of origin was not reported. None of these were unsuitable for examination. The numbers of animals examined within each category are presented in Table 1.
The samples were collected from carcasses originating from 168 different herds. The mean number of animals tested per herd was two (range 1-13). From 51 herds more than two samples were tested.
Scrapie was not detected in goats in 2011. The first and only scrapie case in naturally infected goats in Norway was diagnosed in 2006 and originated from a county with a large goat population. Both classical and atypical scrapie in goats has been diagnosed in several countries in Europe (5).
May 15, 2012 – E-mail: email@example.com www.vetinst.no. ISSN 1890-9973. Title: The surveillance and control programme for scrapie in Norway 2011 ...
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May 15, 2012 – E-mail: firstname.lastname@example.org www.vetinst.no. ISSN 1890-9973. Title: The surveillance and control programme for scrapie in Norway 2011 ...
Atypical scrapie in a swiss goat and implications for transmissible spongiform encephalopathy surveillance
Seuberlich T, Botteron C, Benestad SL, Brunisholz H, Wyss R, Kihm U, Schwermer H, Friess M, Nicolier A, Heim D, Zurbriggen A. Atypical scrapie in a swiss goat and implications for transmissible spongiform encephalopathy surveillance. J Vet Diagn Invest 2007; 19: 2-8.
Different types of transmissible spongiform encephalopathies (TSEs) affect sheep and goats. In addition to the classical form of scrapie, both species are susceptible to experimental infections with the bovine spongiform encephalopathy (BSE) agent, and in recent years atypical scrapie cases have been reported in sheep from different European countries. Atypical scrapie in sheep is characterized by distinct histopathologic lesions and molecular characteristics of the abnormal scrapie prion protein (PrPsc). Characteristics of atypical scrapie have not yet been described in detail in goats. A goat presenting features of atypical scrapie was identified in Switzerland. Although there was no difference between the molecular characteristics of PrPsc in this animal and those of atypical scrapie in sheep, differences in the distribution of histopathologic lesions and PrPsc deposition were observed. In particular the cerebellar cortex, a major site of PrPsc deposition in atypical scrapie in sheep, was found to be virtually unaffected in this goat. In contrast, severe lesions and PrPsc deposition were detected in more rostral brain structures, such as thalamus and midbrain. Two TSE screening tests and PrPsc immunohistochemistry were either negative or barely positive when applied to cerebellum and obex tissues, the target samples for TSE surveillance in sheep and goats. These findings suggest that such cases may have been missed in the past and could be overlooked in the future if sampling and testing procedures are not adapted. The epidemiological and veterinary public health implications of these atypical cases, however, are not yet known.
The surveillance and control programme for Chronic Wasting Disease (CWD) in wild and captive cervids in Norway
Chronic wasting disease (CWD) was not detected in any of the animals tested in 2008.
CWD is a transmissible spongiform encephalopathy (TSE) of cervids (1, 2, 3). A few species of the family Cervidae are known to be naturally susceptible to the disease: mule deer (Odocoileus hemionus), white-tailed deer (O. virginianus), elk (Cervus elaphus), and moose (Alces alces). CWD was first described as a clinical syndrome termed “chronic wasting disease” in captive mule deer in Colorado, USA in the late 1960s and subsequently identified as a TSE in 1978 (1). Chronic wasting disease is so far only diagnosed in free-ranging and captive cervids in North America, and is yet to be diagnosed in cervids in Europe.
Four cervid species are prevalent in natural populations in Norway: moose (Alces alces), red deer (Cervus elaphus), roe deer (Capreolus capreolus), and reindeer (Rangifer tarandus). Red deer predominate along the west coast, whereas moose and roe deer mainly inhabit other areas of the country. The wild reindeer live in dispersed populations in separate high mountain areas in southern Norway. The number officially hunted in 2008 was: 35,600 moose, 35,700 red deer, 29,800 roe deer, and 5,200 wild reindeer. Additionally, Norway has a semi-domestic reindeer population, mainly kept in the northern parts of the country, presently counting about 200,000 animals.
There are 75 cervid farms in Norway. Most of the farms keep red deer, and only a few keep fallow deer (Dama dama).
Based on the fact that Norway has large free-ranging populations of various cervids, a number of them grazing in regions where scrapie is detected, a passive surveillance programme for CWD in Norwegian wild and captive cervids has been running from 2003. In addition, samples from slaughtered semi-domestic reindeer from several regions in the country have been tested for CWD.
Norway performed an EC survey for CWD in cervids in 2006 and 2007 according to Commission decision 2007/182/EC. The target species relevant for Norway was wild red deer and the survey implied sampling of a) clinical/sick, euthanized animals, b) traffic killed animals, c) animals found dead, and d) healthy animals shot during hunting. Additionally, for moose, roe deer, reindeer, and farmed deer the categories a) – c) were sampled. All samples were negative for CW
A small population of approximately 200 free-ranging musk ox (Ovibus moschatus, belonging to the Bovidae), inhabits the Dovre high mountain plateau in Mid-Norway. TSE has not been diagnosed in the musk ox, but the species has been included in the programme from 2004.
The aim of the programme is to detect the possible occurrence of CWD in the Norwegian cervid population.
Material and methods
Tested animals included captive deer and wild cervids older than 18 months that died or were euthanized due to disease or injuries. Additionally, cervids older than 18 months necropsied at the National Veterinary Institute were examined for CWD. Twelve ordinary hunted roe deer from Vestby in the county of Akershus and one musk ox found dead were also tested. The number and species analysed for CWD in 2008 are given in Table 1.
A rapid test (either TeSeE ® Bio-Rad or TeSeE Sheep & Goat ® ELISA, Bio-Rad) was used to screen brain samples for detection of the PrPCWD. All the samples were analysed at the National Veterinary Institute, which is the National Reference Laboratory for TSEs in Norway.
None of the 47 samples analysed tested positive for CWD in the rapid test (Table 1).
Totally 25 of the tested animals were exclusively examined for CWD, and the majority was healthy hunted and traffic killed roe deer (Table 1). The remaining 22 animals represent cases received at the National Veterinary Institute for routine necropsy.
A total of two of the tested animals were captive red deer. One semi-domestic reindeer was sampled because of showing clinical signs before it dropped dead.
Table 1. The number of cervids tested in the Norwegian surveillance and control programme for Chronic wasting disease (CWD) 2008, distributed by reason for submission.
No animals were positive for CWD in 2008. A large part of the tested animals in 2008 was roe deer collected in Vestby, comprising hunted and traffic killed animals. Very few captive red deer were tested.
Among the Norwegian cervid species, a higher risk for CWD can be assumed for red deer and moose since these species are among those known to be naturally susceptible to the disease (1, 2, 3). Regarding moose, so far, only a few positive CWD cases has been diagnosed in hunted animals in CWD-endemic areas in Colorado, USA (3), thus they probably represent preclinical CWD. Also, the disease has been transmitted experimentally to moose by oral inoculation of brain tissue from a CWD affected mule deer (4). Roe deer, reindeer and musk ox has so far not been found naturally infected with CWD.
Monday, June 18, 2012
natural cases of CWD in eight Sika deer (Cervus nippon) and five Sika/red deer crossbreeds captive Korea and Experimental oral transmission to red deer (Cervus elaphus elaphus)
Friday, February 11, 2011
Atypical/Nor98 Scrapie Infectivity in Sheep Peripheral Tissues
Atypical/Nor98 scrapie was first identified in 1998 in Norway. It is now considered as a worldwide disease of small ruminants and currently represents a significant part of the detected transmissible spongiform encephalopathies (TSE) cases in Europe. Atypical/Nor98 scrapie cases were reported in ARR/ARR sheep, which are highly resistant to BSE and other small ruminants TSE agents. The biology and pathogenesis of the Atypical/Nor98 scrapie agent in its natural host is still poorly understood. However, based on the absence of detectable abnormal PrP in peripheral tissues of affected individuals, human and animal exposure risk to this specific TSE agent has been considered low. In this study we demonstrate that infectivity can accumulate, even if no abnormal PrP is detectable, in lymphoid tissues, nerves, and muscles from natural and/or experimental Atypical/Nor98 scrapie cases. Evidence is provided that, in comparison to other TSE agents, samples containing Atypical/Nor98 scrapie infectivity could remain PrPSc negative. This feature will impact detection of Atypical/Nor98 scrapie cases in the field, and highlights the need to review current evaluations of the disease prevalence and potential transmissibility. Finally, an estimate is made of the infectivity loads accumulating in peripheral tissues in both Atypical/Nor98 and classical scrapie cases that currently enter the food chain. The results obtained indicate that dietary exposure risk to small ruminants TSE agents may be higher than commonly believed.
In 1998 an Atypical/Nor98 Scrapie was identified in Norwegian sheep; the PrPSc signature was partially PK resistant and displayed a multi-band pattern as showed by Western Blot (WB) that contrasted with those normally observed in small ruminants TSE cases . After 2001 and the implementation of active TSE surveillance plans, a number of similar cases were identified in most EU members states as well in other countries, like Canada, USA and New Zealand . The transmissibility of Atypical/Nor98 agent has been demonstrated in both rodent models (transgenic animals expressing the ovine Prnp gene)  and sheep , . Currently Atypical/Nor98 Scrapie represents a significant part of the TSE cases identified in the EU small ruminant population, where its prevalence was estimated to range between 5 to 8 positive small ruminants per 10,000 tested per year .
Atypical/Nor98 cases are identified in older animals in comparison to classical scrapie , . The lack of PrPSc detection in peripheral tissues of reported cases suggested that Atypical/Nor98 scrapie agent could be restricted to CNS. This is supportive of the hypothesis that Atypical/Nor98 scrapie could be a spontaneous disorder of PrP folding and metabolism occurring in aged animals without external cause , .
However, this hypothesis is questioned by the evidence reported here that a negative PrPSc testing result could be observed in animals harbouring high infectious titre in their brain and that the infectious agent can be present in peripheral tissues of Atypical/Nor98 scrapie incubating sheep. TSE are considered to be transmitted following oral exposure; initial uptake is followed by a peripheral replication phase which is generally associated with a dissemination of the agent in the lymphoid system and the deposition of large amounts of PrPSc. This peripheral replication phase is later followed by the entry of the infectious agent into the CNS through the autonomic nervous system , , , . However, in several situations, like BSE in cattle , ,  or classical scrapie in ARR heterozygote sheep , , the involvement of secondary lymphoid system is marginal, which does not preclude central neuro-invasion through the autonomic nervous system . It could be proposed that Atypical Scrapie/Nor98 might occur following oral exposure to a TSE agent, which would spread marginally in lymphoid tissues before neuro-invasion. The slow propagation of Atypical Scrapie/Nor98 in its host (long incubation period) and the impaired detection sensitivity level of PrPSc based assays would explain the apparent old age of detected cases.
The results presented here are insufficient to rule out the hypothesis of a spontaneous/non contagious disorder or to consider this alternative scenario as a plausible hypothesis. Indeed, the presence of Atypical scrapie/Nor98 infectivity in peripheral tissues could be alternatively due to the centripetal spreading of the agent from the CNS. However, our findings point out that further clarifications on Atypical/Nor98 scrapie agent biology are needed before accepting that this TSE is a spontaneous and non contagious disorder of small ruminants. Assessing Atypical/Nor98 scrapie transmissibility through oral route in natural host and presence in placenta and in colostrum/milk (which are considered as major sources for TSE transmission between small ruminants) ,  will provide crucial data.
The presence of infectivity in peripheral tissues that enter the food chain clearly indicates that the risk of dietary exposure to Atypical/Nor98 scrapie cannot be disregarded. However, according to our observations, in comparison to the brain, the infectious titres in the peripheral tissues were five log10 lower in Atypical/Nor98 scrapie than in classical scrapie. Therefore, the reduction of the relative exposure risk following SRM removal (CNS, head, spleen and ileum) is probably significantly higher in Atypical/Nor98 scrapie cases than in classical scrapie cases. However, considering the currently estimated prevalence of Atypical/Nor98 scrapie in healthy slaughtered EU population , it is probable that atypical scrapie infectivity enters in the food chain despite the prevention measures in force.
Finally, the capacity of Atypical/Nor98 scrapie agent (and more generally of small ruminants TSE agents) to cross species barrier that naturally limits the transmission risk is insufficiently documented. Recently, the transmission of an Atypical/Nor98 scrapie isolate was reported into transgenic mice over-expressing the porcine PrP . Such results cannot directly be extrapolated to natural exposure conditions and natural hosts. However, they underline the urgent need for further investigations on the potential capacity of Atypical/Nor98 scrapie to propagate in other species than small ruminants.
please see more transmissions studies here ;
Friday, February 11, 2011
Atypical/Nor98 Scrapie Infectivity in Sheep Peripheral Tissues
Monday, April 25, 2011
Experimental Oral Transmission of Atypical Scrapie to Sheep
Volume 17, Number 5-May 2011
Tuesday, July 17, 2012
O.I.E. BSE, CWD, SCRAPIE, TSE PRION DISEASE Final Report of the 80th General Session, 20 - 25 May 2012
Thursday, December 20, 2012
OIE GROUP RECOMMENDS THAT SCRAPE PRION DISEASE BE DELISTED AND SAME OLD BSe WITH BOVINE MAD COW DISEASE
***The pathology features of Nor98 in the cerebellum of the affected sheep showed similarities with those of sporadic Creutzfeldt-Jakob disease in humans.
*** Intriguingly, these conclusions suggest that some pathological features of Nor98 are reminiscent of Gerstmann-Sträussler-Scheinker disease.
*** These observations support the view that a truly infectious TSE agent, unrecognized until recently, infects sheep and goat flocks and may have important implications in terms of scrapie control and public health.
Furthermore, after adaptation in the porcine mouse model this prion showed similar biological and biochemical characteristics than BSE adapted to this porcine mouse model. Altogether these data indicate.
(i) the unsuspected potential abilities of atypical scrapie to cross species barriers
(ii) the possible capacity of this agent to acquire new characteristics when crossing species barrier
These findings raise some interrogation on the concept of TSE strain and on the origin of the diversity of the TSE agents and could have consequences on field TSE control measures.
Wednesday, January 18, 2012
Selection of Distinct Strain Phenotypes in Mice Infected by Ovine Natural Scrapie Isolates Similar to CH1641 Experimental Scrapie
Journal of Neuropathology & Experimental Neurology:
February 2012 - Volume 71 - Issue 2 - p 140–147
Thursday, March 29, 2012
atypical Nor-98 Scrapie has spread from coast to coast in the USA 2012
NIAA Annual Conference April 11-14, 2011San Antonio, Texas
Monday, November 30, 2009
USDA AND OIE COLLABORATE TO EXCLUDE ATYPICAL SCRAPIE NOR-98 ANIMAL HEALTH CODE
Thursday, December 20, 2012
OIE GROUP RECOMMENDS THAT SCRAPE PRION DISEASE BE DELISTED
why do we not want to do TSE transmission studies on chimpanzees $
5. A positive result from a chimpanzee challenged severly would likely create alarm in some circles even if the result could not be interpreted for man. I have a view that all these agents could be transmitted provided a large enough dose by appropriate routes was given and the animals kept long enough. Until the mechanisms of the species barrier are more clearly understood it might be best to retain that hypothesis.
Wednesday, February 16, 2011
SCRAPIE TRANSMISSION TO CHIMPANZEES
Sunday, December 12, 2010
EFSA reviews BSE/TSE infectivity in small ruminant tissues News Story 2 December 2010
Sunday, April 18, 2010
SCRAPIE AND ATYPICAL SCRAPIE TRANSMISSION STUDIES A REVIEW 2010
Thursday, December 23, 2010
Molecular Typing of Protease-Resistant Prion Protein in Transmissible Spongiform Encephalopathies of Small Ruminants, France, 2002-2009
Volume 17, Number 1 January 2011
Thursday, November 18, 2010
Increased susceptibility of human-PrP transgenic mice to bovine spongiform encephalopathy following passage in sheep
Michigan and California have had a high spike in Goat Scrapie cases, compared to elsewhere ???
three is a serious problem with scrapie in goats around Michigan, Ohio, and California, that no one can explain, and it’s not because I have not tried to make them aware of it ;
----- Original Message -----
From: "BioMed Central Comments"
Sent: Wednesday, February 16, 2011 4:13 AM
Subject: Your comment on BMC Veterinary Research 2011, 7:7
Your discussion posting "Scrapie cases Goats from same herd USA Michigan" has been rejected by the moderator as not being appropriate for inclusion on the site.
Dear Mr Singeltary,
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BMC Veterinary Research
Tuesday, February 01, 2011
Sparse PrP-Sc accumulation in the placentas of goats with naturally acquired scrapie
(Figure 6) including five goat cases in FY 2008 that originated from the same herd in Michigan. This is highly unusual for goats, and I strenuously urge that there should be an independent investigation into finding the common denominator for these 5 goats in the same herd in Michigan with Scrapie. ...
Wednesday, February 20, 2013
World Organization for Animal Health Recommends United States' BSE Risk Status Be Upgraded
Statement from Agriculture Secretary Tom Vilsack:
Thursday, February 14, 2013
The Many Faces of Mad Cow Disease Bovine Spongiform Encephalopathy BSE and TSE prion disease
Friday, February 08, 2013
*** Behavior of Prions in the Environment: Implications for Prion Biology
Friday, November 09, 2012
*** Chronic Wasting Disease CWD in cervidae and transmission to other species
Sunday, November 11, 2012
*** Susceptibilities of Nonhuman Primates to Chronic Wasting Disease November 2012
Friday, December 14, 2012
Susceptibility Chronic Wasting Disease (CWD) in wild cervids to Humans 2005 - December 14, 2012
>>>There are 75 cervid farms in Norway. Most of the farms keep red deer, and only a few keep fallow deer (Dama dama).<<<<
Tuesday, December 18, 2012
*** A Growing Threat How deer breeding could put public trust wildlife at risk
NORWAY HUMAN TSE PRION DISEASE
EUROCJD Surveillance Data
Total Cases of CJD/GSS (Deaths)
All Definite And Probable Cases:
Sporadic, Familial/Genetic, FFI, GSS and Iatrogenic Deaths (excluding vCJD)
Country 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 Total
Norway - - - - 6 2 2 4 6 3 6 8 4 4 5 3 5 2 4 64
All CJD (excluding vCJD): Annual Mortality Rates Per Million
Norway - - - - 1.37 0.45 0.45 0.89 1.33 0.66 1.32 1.75 0.87 0.86 1.07 0.63 1.04 0.41 0.81 0.92
Incidence / incidence rate 2006
4 / 0.9 per 1 million population
All four cases of Creutzfeldt-Jacob disease (CJD) reported in 2006 were classified as sporadic CJD following autopsies.
Suspected and confirmed cases of human transmissible spongiform encephalopathies were made notifiable conditions in 1997.
All cases of CJD registered in Norway so far have been sporadic CJD confirmed by autopsy. One of the cases is suspected to be a hereditary case. Cases of iatrogenic or variant CJD have never been registered in Norway. BSE has never been identified in Norwegian cattle.
Table 35. Creutzfeldt-Jakob disease notifications in Norway 2000-2006 by year of death.
2000 2001 2002 2003 2004 2005 2006
3 5 3 5 7 4 4
*** The discovery of previously unrecognized prion diseases in both humans and animals (i.e., Nor98 in small ruminants) demonstrates that the range of prion diseases might be wider than expected and raises crucial questions about the epidemiology and strain properties of these new forms. We are investigating this latter issue by molecular and biological comparison of VPSPr, GSS and Nor98.
VARIABLY PROTEASE-SENSITVE PRIONOPATHY IS TRANSMISSIBLE ...price of prion poker goes up again $
OR-10: Variably protease-sensitive prionopathy is transmissible in bank voles
Romolo Nonno,1 Michele Di Bari,1 Laura Pirisinu,1 Claudia D’Agostino,1 Stefano Marcon,1 Geraldina Riccardi,1 Gabriele Vaccari,1 Piero Parchi,2 Wenquan Zou,3 Pierluigi Gambetti,3 Umberto Agrimi1 1Istituto Superiore di Sanità; Rome, Italy; 2Dipartimento di Scienze Neurologiche, Università di Bologna; Bologna, Italy; 3Case Western Reserve University; Cleveland, OH USA
Background. Variably protease-sensitive prionopathy (VPSPr) is a recently described “sporadic”neurodegenerative disease involving prion protein aggregation, which has clinical similarities with non-Alzheimer dementias, such as fronto-temporal dementia. Currently, 30 cases of VPSPr have been reported in Europe and USA, of which 19 cases were homozygous for valine at codon 129 of the prion protein (VV), 8 were MV and 3 were MM. A distinctive feature of VPSPr is the electrophoretic pattern of PrPSc after digestion with proteinase K (PK). After PK-treatment, PrP from VPSPr forms a ladder-like electrophoretic pattern similar to that described in GSS cases. The clinical and pathological features of VPSPr raised the question of the correct classification of VPSPr among prion diseases or other forms of neurodegenerative disorders. Here we report preliminary data on the transmissibility and pathological features of VPSPr cases in bank voles.
Materials and Methods. Seven VPSPr cases were inoculated in two genetic lines of bank voles, carrying either methionine or isoleucine at codon 109 of the prion protein (named BvM109 and BvI109, respectively). Among the VPSPr cases selected, 2 were VV at PrP codon 129, 3 were MV and 2 were MM. Clinical diagnosis in voles was confirmed by brain pathological assessment and western blot for PK-resistant PrPSc (PrPres) with mAbs SAF32, SAF84, 12B2 and 9A2.
Results. To date, 2 VPSPr cases (1 MV and 1 MM) gave positive transmission in BvM109. Overall, 3 voles were positive with survival time between 290 and 588 d post inoculation (d.p.i.). All positive voles accumulated PrPres in the form of the typical PrP27–30, which was indistinguishable to that previously observed in BvM109 inoculated with sCJDMM1 cases.
In BvI109, 3 VPSPr cases (2 VV and 1 MM) showed positive transmission until now. Overall, 5 voles were positive with survival time between 281 and 596 d.p.i.. In contrast to what observed in BvM109, all BvI109 showed a GSS-like PrPSc electrophoretic pattern, characterized by low molecular weight PrPres. These PrPres fragments were positive with mAb 9A2 and 12B2, while being negative with SAF32 and SAF84, suggesting that they are cleaved at both the C-terminus and the N-terminus. Second passages are in progress from these first successful transmissions.
Conclusions. Preliminary results from transmission studies in bank voles strongly support the notion that VPSPr is a transmissible prion disease. Interestingly, VPSPr undergoes divergent evolution in the two genetic lines of voles, with sCJD-like features in BvM109 and GSS-like properties in BvI109.
The discovery of previously unrecognized prion diseases in both humans and animals (i.e., Nor98 in small ruminants) demonstrates that the range of prion diseases might be wider than expected and raises crucial questions about the epidemiology and strain properties of these new forms. We are investigating this latter issue by molecular and biological comparison of VPSPr, GSS and Nor98.
Wednesday, March 28, 2012
VARIABLY PROTEASE-SENSITVE PRIONOPATHY IS TRANSMISSIBLE, price of prion poker goes up again $
Thursday, February 21, 2013
National Prion Disease Pathology Surveillance Center Cases Examined January 16, 2013