SEAC 99th meeting on Friday 14th December 2007
1 09.30 Introduction SEAC Chair
Approval of draft minutes from SEAC 98
SPONGIFORM ENCEPHALOPATHY ADVISORY COMMITTEE
Draft open minutes of the 98th meeting held on 29th July 2007
23. The Chair summarised the discussion noting that SEAC agreed: • there are no substantive new data to allow a reassessment of the infectivity of plasma derivatives from fractionation of contaminated plasma. • only research that measures the clearance of endogenous infectivity in blood would support a reassessment of the infectivity of plasma derivatives. • the National Haemophiliac Database could provide important data to assess the risks of transmission of vCJD via plasma derivatives.
32. A member noted that from a public and consumer perspective SEAC has always been seen as an exemplar of good practice for example by holding its meetings in public and communicating its statements and decisions using clear language. It was noted that the House of Commons report is not in favour of consumer or lay representatives on all scientific committees as a matter of course and it advises that their roles are re-evaluated. The member noted that lay members are in fact important in ensuring that information produced by committees can be understood by non-experts. However, it is important to make clear that a single consumer representative cannot represent the thoughts of all consumers. Periodic review of scientific advisory committees, such as is
undertaken with SEAC, is important as a quality assurance mechanism.
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USE OF PREVIOUS SEAC OPINIONS ISSUE
1. Given the evolving nature of scientific understanding of transmissible spongiform encephalopathies (TSEs), it is suggested that an agreed procedure be in place setting out a time limit for the use of SDEAC advice by a Government Department without referral back to the committee. It is suggested this is needed because new data could have appeared since the advice was given that would cause the committee to alter that advice.
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REPORT FROM THE SEAC SHEEP SUBGROUP
31. Given the low prevalence of classical scrapie and assuming that BSE in sheep would occur independently from that of classical scrapie, if BSE is or was present in the national sheep flock, it would have been expected to arise more frequently as a single infection rather than mixed with classical scrapie. However, since BSE as a single infection in sheep has never been found, it is highly unlikely that an appreciable number of mixed infections of classical scrapie and BSE are present currently in sheep unless BSE and classical scrapie are more efficiently transmitted together between sheep compared with BSE in isolation but there are no data to suggest this may or may not be the case. However, unpublished results from inoculations into mice of a mixed inoculum compared with individual inocula indicate an increased attack rate suggesting higher transmission efficiencies of mixed strains is a possibility12.
Summary 33. The data from the strain typing study, while intriguing and not fully explained, provide no evidence for the presence of BSE in sheep as a single infection. Whilst these data may indicate the presence of mixed BSE and classical scrapie infections, this is one of several possible interpretations. These data should not give rise to concern that there is an appreciable number of mixed BSE-12 classical scrapie infections that would significantly influence estimates of the prevalence of BSE in the UK sheep flock.
Unpublished Roslin Institute studies.
13 SEAC Sheep Subgroup statement (2006)
14 Opinion on the quantitative risk assessment on the residual BSE risk in sheep meat and meat products. The EFSA Journal. (2007) 442, 1-44.
Maternal transfer of classical scrapie prion protein via sheep milk Background 34. The mechanisms for transmission of classical scrapie between sheep are not fully understood, however there is evidence to suggest that the risk of transmission is high during the neonatal period15. A study by VLA is examining whether milk may be a significant route of transmission by bottle feeding milk collected from ewes genetically susceptible to, and infected with classical scrapie, to genetically susceptible TSE-free lambs. Data 35. Early unpublished findings from the study suggest that milk may be a route of transmission. Post mortem examination of three lambs that were bottle-fed milk from classical scrapie infected ewes which died early in the study from intercurrent disease revealed the presence of PrPSc in gut lymphoid tissue in two lambs. The milk fed to these two lambs was from two ewes that developed clinical signs of classical scrapie during lactation. The milk fed to the third lamb was from a ewe with clinical signs of classical scrapie at the beginning of lactation from which only a relatively small volume of milk was produced. Somatic cell counts were high in at least a proportion of the milk collected from the ewes. PrPSc was not found in a control lamb, which also died from intercurrent disease, that was fed milk from an uninfected ewe. Implications 36. These data suggest that PrPSc may be transmitted from ewe to lamb via milk or colostrum. As a full lactation was fed to the lambs it is not possible to determine whether transmission occurred via colostrum and/or the subsequent milk. The study is at too early a stage to assess whether classical scrapie develops as a result of this exposure, although this should be considered likely.
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SCIENTIFIC BASIS FOR CLASSICAL SCRAPIE CONTROLS
Scientific basis for relaxation of classical scrapie controls
AFSSA OPINION 13. The AFSSA opinion (Annex 1) describes three areas of scientific uncertainty that have led to the conclusion that the proposed changes to controls may significantly increase the risk to human health from the slaughter of sheep from classical scrapie affected flocks for human consumption. In summary, AFSSA considered that: • the tests to detect and discriminate between BSE and classical and atypical scrapie are limited as (i) their sensitivity has not been accurately determined, (ii) they may not detect BSE in animals that are also infected with classical scrapie and (iii) the conduct of the discriminatory test on the index case would not guarantee the absence of BSE in the flock. Furthermore, as only brain tissue is tested, the rapid tests cannot detect TSE infections during the incubation period prior to accumulation of abnormal prion protein in the brain. • although there are no epidemiological data to suggest a link between classical scrapie strains and human TSEs, in view of the diversity of classical scrapie strains and the lack of a robust prospective study to examine potential links between these TSE strains and human TSEs, a link cannot be ruled out. • the incidence of classical scrapie infections in classical scrapie affected sheep flocks can be relatively high, particularly in those animals of susceptible genotypes5 suggesting classical scrapie infection may be widespread in affected flocks. 14. In view of these considerations, AFSSA concluded that allowing animals from classical scrapie affected flocks to be slaughtered for human consumption, particularly without any restriction on genotype, would increase the human health risk as: (i) the presence of BSE in a sheep cannot be ruled out by the application of discriminatory tests as the sensitivity of the tests is not known precisely and detection may be compromised when classical scrapie is also present. (ii) classical scrapie infections can be widespread in sheep flocks and as rapid TSE tests cannot identify infected animals in the early part of the incubation period, it is possible that an appreciable number of classical scrapie infected animals could enter the human food chain. (iii) the transmission to humans of TSE strains other than BSE cannot be ruled out.
5 Corbiere et al. (2007) Advanced survival models for risk-factor analysis in scrapie. J. Gen Virol. 88, 696-705.
EFSA OPINION 15.
The EFSA Scientific Panel on Biological Hazards considered the AFSSA opinion and in particular the evidence for possible links between classical or atypical scrapie and human TSEs and the performance characteristics of discriminatory tests for sheep TSEs (Annex 2). The Panel concluded that: • there is no evidence for an epidemiological or molecular link between classical and/or atypical scrapie and TSEs in humans. The BSE agent is the only agent identified as zoonotic. However, in view of their diversity it is currently not possible to exclude transmissibility to humans of other animal TSE agents. • current discriminatory tests appear, up to now, to be reliable for the differentiation of BSE from classical and atypical scrapie. However, at the current stage of scientific knowledge, neither their diagnostic sensitivity nor their specificity can be assumed to be perfect. KOM AG TSE OPINION 16. KOM AG TSE considered the changes to classical scrapie controls (Annex 4) and noted that recently published research by Reckzeh et al. (2007)6 (Annex 4) showed that some sheep of susceptible genotypes that had tested negative for TSE infection when brain samples were tested, were in fact positive for TSE infection when peripheral tissues were tested. Thus, the committee concluded that the current strategy of testing brain tissue cannot exclude the presence of TSE infections at the stage of the incubation period prior to involvement of the brain. Thus, the changes to classical scrapie controls could allow classical scrapie infectivity into the human food chain. 17. In addition, the committee noted that, although the EFSA Biohazard Panel concluded that there are no indications of the existence of zoonotic link between classical scrapie and human TSEs, as classical scrapie strains are not uniform and are poorly defined, a zoonotic potential cannot be ruled out. In view of this, the committee considered that consumer exposure to classical scrapie should be avoided and was not in favour of the changes to the classical scrapie controls that would allow this to occur.
6 Reckzeh et al. (2007) Rapid testing leads to the underestimation of the scrapie prevalence in an affected sheep and goat flock. Vet. Microbiol. 123, 320-327.
PREVIOUS SEAC OPINIONS
Opinion of the French Food Safety Agency (AFSSA) on changes to the control measures for sheep and goat herds in which a case of classical or atypical scrapie has been detected
Opinion of the Scientific Panel on Biological Hazards on certain aspects related to the risk of transmissible spongiform encephalopathies (TSEs) in ovine and caprine animals
5- Conclusions and opinion
On the following grounds:
- the discriminatory tests do not enable the presence of BSE to be ruled out either in the tested animal or by extension in the flock to which it belongs;
- the transmission to humans of TSE strains other than BSE cannot be ruled out;
- the knowledge acquired of the genetic susceptibility of sheep to scrapie and BSE should be used, insofar as this is possible, to limit the risk of consumer exposure,
The Committee is making the following recommendations:
Recommendations common to both types of control measure:
- permanent individual identification of all small ruminants belonging to the herds concerned.
- for sheep, genotyping for the four cordons (136, 141, 154 and 171) of all animals in an infected flock.
- all tests carried out on animals slaughtered or culled as part of the control measures must be effected with one of the rapid tests with the best sensitivity for the detection of atypical scrapie (currently Idexx, Biorad).
- conduct of a discriminatory test on all secondary cases identified.
- destruction of all positive animals.
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Opinion of the KOM AG TSE Evaluation of the catalogue of measures after detecting a TSE case Reckzeh et al. (2007) Rapid testing leads to the underestimation of the scrapie prevalence in an affected sheep and goat flock. Vet. Microbiol. 123, 320-327.
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Consideration of various options relating to relaxation of the total feed ban
1. The Department for Environment, Food and Rural Affairs (Defra) the devolved Rural Affairs Departments and the Food Standards Agency (FSA) have asked SEAC to consider, in qualitative terms, the potential for further transmissible spongiform encephalopathy (TSE) infections and epidemics to arise as a result of possible implementation of various future options for relaxing the TSE-related feed controls. This paper, prepared by Defra, provides an overview of European Union (EU) proposals and relevant science.
Work Programme8 on TSEs in November 2006. In relation to the feed ban, the document proposed discussions on:
i. Permitting a tolerance of “insignificant amounts” of animal protein, including fish meal in feed, arising as a result of “adventitious” (e.g. rodent/avian) or “technically unavoidable” (e.g. fish meal) contamination.
ii. The use of fish meal in feed for young ruminants on the basis of a scientific assessment of their dietary needs and following an assessment of the control aspects.
iii. Permitting a general tolerance level with regard to the “small presence” of mammalian MBM in feed for farmed animals.
Currently it is not possible to expand on the terms “insignificant amount” or “small presence”. Any future tolerance level would be determined to a large extent by the sensitivity and specificity of the quantitative tests available. Quantitative risk assessments (e.g. EFSA quantitative risk assessment of animal BSE risk posed by mammalian MBM 2005) may also be taken into account. Also it is not clear exactly what is envisaged under (iii) but the UK Government’s current understanding is that it is a variation on (i) in that an accepted “tolerance” level would be agreed below which the Member State would not be obliged to investigate and assess the individual risk.
9. In January 2007, the TSE Regulation was amended by co-decision. This provided a legal basis for the future options of (i) feeding fishmeal to young ruminants only – a political compromise between the European Commission which wanted the option of permitting the feeding of fish meal to ruminants and the European Parliament which opposed the feeding of such animal protein to herbivores on “ethical” grounds, but conceded to allowing the option of feeding fish meal to young ruminants based on a scientific assessment of their dietary needs – and (ii) the introduction of a risk-based tolerance level for the presence of “insignificant” amounts of animal protein in feed “caused through adventitious and technically unavoidable contamination”. Apart from the circumstances outlined above (and existing exemptions), the ban on feeding animal protein to ruminants remained. The TSE Regulation required that rules for the prevention of cross contamination and methods of sampling and analysis to check compliance, should be based upon a European Commission report covering the sourcing, processing, control and traceability of feedingstuffs of animal origin. The recitals of the TSE Regulation were also amended to propose that “the feeding to non-ruminants of certain PAP originating from non-ruminants should be allowed taking into account the prohibition on intra-species recycling…
and the control aspects in particular linked to differentiation of PAP specific to certain species”: this proposal could be agreed by the European Commission and EU Member States. 10. At SEAC 98 (July 2007) following the media coverage referred to in paragraph 7, SEAC “considered it important that Defra should seek the views of SEAC should such a policy [of feeding non-ruminant MBM to non-ruminants] be proposed as part of the TSE Roadmap”. 11. In July 2007, the European Parliament adopted a report9, which called on the European Commission and the European Council to “lift the ban on feeding fish meal and fish oil to ruminants” (although there is no ban on feeding fish oil to ruminants). The report stressed that "there is no scientific evidence to support a total ban on fish meal on the grounds that it may transmit BSE or other TSEs". 12. In September 2007, the European Commission tabled a proposal (SANCO/2017/2007) to permit the use of fish meal in milk replacers for feeding to young ruminants before weaning, while maintaining strict controls on the feeding of fish meal to adult ruminants, in line with the requirements of the TSE Regulation. In November 2007, the European Commission discussed an amended proposal (SANCO/2017/2007rev.1) to permit the use of fish meal in milk replacers for feeding to young ruminants, with Member States. The amended proposal indicated that it applied to milk replacers administered in either dry or liquid form, provided to young ruminants as a supplement or milk substitute before the completion of weaning. The Commission explained that the European Food Safety Authority had advised that a scientific assessment of the dietary needs of young ruminants was outside its remit. Consequently, the Commission was considering establishing a group of animal nutrition experts to carry out this task. The European Commission indicated following additional training, the qualitative performance of National Reference Laboratories had improved beyond the position reported from the 2006 inter-laboratory trial. However, no further progress could be made on tolerance proposals (e.g. an agreed tolerance level for the presence of fish meal in adult ruminant feed) until there had been a significant improvement in the performance of quantitative tests and this could take at least a year. The European Commission undertook to make data relating to the assessment of dietary needs (EFSA) and the assessment of control aspects (further report from Community Reference Laboratory for Animal Proteins) available to Member States in due course.
9 European Parliament (2007) European Parliament resolution of 10 July 2007 on industrial fisheries and the production of fishmeal and fish oil. P6_TA-PROV(2007)0327
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1. To consider emerging scientific issues in relation to transmissible spongiform encephalopathies (TSEs) and to raise awareness of issues SEAC may consider in the future.
SEAC 99/5 ANNEX 1 DEFRA
To advise SEAC of possible animal-health related TSE developments in 2008.
World Organisation for Animal Health (OIE)
The World Organisation for Animal Health is considering current trade guidelines on scrapie and BSE in relation to the emergence of atypical forms of the diseases. While it is unlikely that changes are required to guidelines for BSE, significant revision will be required to take into account the implications of atypical scrapie.
The OIE is expected to endorse the provisional recognition of the UK as “controlled risk” for BSE, at its General Session in May 2008 .
2. European Union Many of the short term goals of the EU’s 2005 TSE Roadmap have been achieved. Those outstanding include:
i) Revision of the BSE Monitoring Programme in Cattle The European Commission is currently discussing a revision of the BSE monitoring programme in cattle, with Member States, to achieve better targeting of the surveillance activity and a reduction in the number of tests. We anticipate that there will be an increase in the testing age limit for fallen stock and date/age based changes to the testing age limit for cattle slaughtered for human consumption. We envisage that SEAC will be consulted on significant changes to the BSE monitoring programme in relation to cattle slaughtered for human consumption.
ii) EU Feed Controls The European Commission is currently discussing the feeding of fish meal to young ruminants, with Member States. The European Commission intends to establish an expert group to examine the nutritional aspects of the proposal. The Community Reference laboratory for animal proteins in feed is working to improve the quantitative method and a further inter-laboratory study is expected. The outcome of this work could pave the way for the introduction of tolerances from 2008. Other research on feed tests could support the feeding of non-ruminant PAP to non-ruminants in the longer term. It may be necessary to consult SEAC again on specific developments.
iii) EU Scrapie Controls
In April 2007, the EU’s Standing Committee on the food chain and animal health adopted more proportionate control measures for scrapie. Following a subsequent legal challenge from France, the European Court of First Instance suspended the new measures relating to classical scrapie pending the hearing of the main case. For sheep flocks in which classical scrapie has been detected the remaining options are whole-flock cull and genotyping and culling. For goats the only remaining option is whole-flock cull. The legal case centred on scientific opinions from the French Food Safety Agency (AFSSA) and the European Food Safety Authority (EFSA) and the application of the precautionary principle. It highlights the importance of close liaison between national risk assessment bodies and EFSA. The Commission is planning to appeal against the judgement and seek acceleration of the main case.
3. TSEs in Cattle
We predict a continued decline in cases of BSE in the EU and estimate fewer than 75 cases in UK by the end of 2007 (compared to 114 in 2006). The majority of cases are still being detected in cattle born before the 1996 feed ban. The Older Cattle Disposal Scheme closes at the end of 2008 and we are working with industry to maximise the uptake. The prevalence in successive BARB birth cohorts is extremely low and appears to be decreasing. However, as the pre-1996 cattle population declines, BARBs will form an increasing percentage of the total number of cases.
The overall prevalence of atypical BSE appears low. Two cases of atypical BSE have been detected in UK to date in older cattle. Oral challenge studies are being planned in Europe and Japan which will provide further information on the pathogenesis. While the aetiology of atypical BSE remains unknown the long term consequences for the maintenance of key BSE controls remains uncertain.
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8 12.15 Public Q&A SEAC Chair
9 13.20 Update on vCJD and sCJD epidemiology Dr R Knight (NCJDSU)
10 13.40 Update on NATA and other vCJD prevalence studies Professor N Gill (HPA) Dr J Clewley (HPA)
11 14.30 Re-assessment of the potential risk of vCJD transmission via dentistry Dr P Bennett (DH) Dr P Grove (DH)
A RE-ASSESSMENT OF THE POTENTIAL RISK OF VCJD TRANSMISSION VIA DENTISTRY ISSUE
1. The Department of Health (DH) has asked SEAC to consider an interim assessment of the potential risk of vCJD transmission via dental procedures. This work builds on previous risk assessments on possible dental transmission considered by SEAC.
Previous SEAC considerations of vCJD transmission via dentistry
The New DH Risk Assessment
8. The research on infectivity just noted forms one strand of a wider programme at the HPA, which is also intended to quantify protein residues found on dental instruments and the effectiveness of sterilisation in reducing infectivity. Following SEAC 97 (May 2007), DH commissioned a comprehensive re-assessment of the potential risks of vCJD transmission associated with dentistry to take account of research at the HPA and elsewhere. The assessment aims to clarify the range of plausible scenarios for vCJD transmission via dental instruments that could occur, given what is currently known, and to identify the most important factors affecting this risk. The assessment will be used to identify the most important areas of further work to address the uncertainties and any robust ways of cost effectively reducing risks further.
9. This new interim risk assessment has been produced by DH analysts (annex 3) in collaboration with a Scientific Reference Group of independent experts (Chaired by Professor Graham Medley). Members of the Group have expertise in dentistry, instrument decontamination, human and animal prion diseases, anatomy, public health, risk assessment modelling and epidemiology. This group met three times to review and refine the modelling framework and agree the risk assessment. The group provided advice on the inputs and assumptions incorporated into the risk assessment, particularly where expert judgement was required due to a lack of hard data. Under circumstances where key data are absent, precautionary assumptions were agreed. As a number of large uncertainties that strongly influence the quantification of risk remain, the risk assessment is considered as interim and will be updated in the future when new scientific evidence becomes available.
10. The assessment examines the risk that vCJD may be transmitted via dental procedures by establishing plausible ranges for key parameters, including (see sections 2 and 3 of the risk assessment):
• the vCJD infectivity of tissues of the oral cavity of infected patients
• the deposition of that material onto different types of dental instruments and the effectiveness of standard cleaning and sterilisation processes used in dental practice
• the mechanisms and efficiency of transfer of vCJD infectivity from contaminated instruments used on subsequent patients
• the probability of transmission based on assessments of the number and types of dental procedure conducted and the number of people who might be carrying an asymptomatic vCJD infection.
As there is lack of substantial data with which to accurately quantify many of these parameters, plausible ranges for these parameters have been established to take account of the often large uncertainties in the data. The large uncertainties in many of these parameters strongly influence the quantification of the risk.
12. Plausible scenarios built up using ranges for each of these factors include many in which dental transmission would have no detectable effect on the course of the vCJD outbreak (see section 4 of the risk assessment). However, there are some which include a combination of pessimistic assumptions as regards the infectivity of dental / oral tissues and the effects of instrument decontamination which suggest that:
• there could be some hundreds of vCJD transmissions per annum via dentistry - albeit against a background of several thousand existing vCJD infections (not clinical cases of vCJD), or where
• dental transmission could generate a self-sustaining reservoir of vCJD infection within the population.
13. The distinction between vCJD infections and clinical cases of vCJD is important. If a large proportion of secondary transmissions result in subclinical infections (either never developing into clinical disease or doing so over an extended time-scale) and those infected are infectious, the likelihood of a self-sustaining epidemic increases. The proportion of individuals who might enter such a subclinical “carrier state” is unknown. Key Assumptions and areas of uncertainty
14. Work on the risk assessment is on-going and new data should enable some of the inputs and assumptions underpinning these scenarios to be revised. Key areas of uncertainty are:
• Infectivity in relevant tissues. Of all the unknowns, that of overriding importance is whether dental/oral tissues in patients incubating vCJD would be infective, and if so at what level.
There are as yet no results of studies using human gingival and dental pulp tissues, and these studies may extend into 2009 and 2010 respectively. This is examined in section 2.3 of the risk assessment.
• Protein Residues on dental instruments. This is examined in section 2.2 of the risk assessment.
• Efficacy of Autoclaving. This is examined in section 2.3 of the risk assessment.
• Current prevalence of vCJD infection. This is examined in section 3.3 of the risk assessment.
• Epidemiology of vCJD. This is examined in section 4 of the risk assessment.
15. Suggested areas of further work to reduce the uncertainty in these key areas are described in section 5 of the risk assessment together with a preliminary analysis of possible interventions and risk reduction measures.
ADVICE SOUGHT FROM THE COMMITTEE
POSITION STATEMENT vCJD AND ENDODONTIC DENTISTRY
5. Evidence suggests that the files and reamers used in endodontic procedures are reused and are difficult to reliably decontaminate4. Appreciable quantities of residual material remain adherent to the surface after normal cleaning and sterilisation5. Thus, there is potential for transfer of dental pulp between patients undergoing endodontic procedures.
vCJD infectivity in dental tissues
6. There are no data on vCJD infectivity in dental pulp. Although no abnormal prions were found in a study of dental tissues, including dental pulp, from vCJD cases6, dental pulp includes blood and peripheral nerve tissue known to carry vCJD infectivity7,8. In addition, appreciable infectivity has been found in the dental pulp of hamsters with hamster scrapie9. Although it is possible that the peripheral nerve may only become infective close to, or after, the onset of clinical vCJD, inflammation may promote the propagation of prions10. Thus, although the data are limited and indirect, it is reasonable to assume that the dental pulp of individuals subclinically-infected with vCJD may be infectious although the level of infectivity is unknown. Studies underway will provide direct data on the infectivity in dental tissues from vCJD cases. level of infectivity is unknown.
4 Letters et al. (2005) A study of visual and blood contamination on reprocessed endodontic files from general dental practice. Br. Dent. J. 199, 522-525. 5 Smith et al. (2005) Residual protein levels on reprocessed dental instruments. J. Hosp. Infect. 61, 237-241. 6 Head et al. (2003) Investigation of PrPres in dental tissues in variant CJD. Br. Dent. J. 195, 339-343. 7 SEAC 91 minutes paragraph 9.
Department of Health (2005) Assessing the risk of vCJD transmission via surgery: an interim view. Unpublished. 9 Ingrosso et al. (1999) Transmission of the 263K scrapie strain by the dental route. J. Gen. Virol. 80, 3043-3047. 10 Heikenwalder et al. (2005) Chronic lymphocytic inflammation specifies the organ tropism of prions. Science. 307, 1107-1110.
Subclinical carrier state
7. A study of humanised mice showed that vCJD infections may not always progress to clinical disease within the normal lifespan of the animals11. Another study suggested that prion infections in mice that remain at a subclinical level can be transmitted to other mice, resulting in clinical disease12. Thus, there is evidence to suggest that individuals infected with the BSE / vCJD agent may remain in a subclinical infection carrier state instead of developing vCJD. A discrepancy between prevalence estimates based on a survey of abnormal prion protein in appendix and tonsil tissue and data on vCJD cases supports this hypothesis13. As no diagnostic test exists to identify such individuals, they could over the course of their lives be potential sources of numerous secondary infections arising from invasive medical or dental procedures.
8. The prevalence of subclinical infection in the UK population is uncertain. A recent estimate suggests the number of subclinical carriers may be of the order of several thousand14. SEAC has strongly recommended that further studies to ascertain better the prevalence of vCJD infection be urgently considered15.
9. The new DH analysis suggests that, on the basis that residual dental pulp on endodontic files and reamers is transferred relatively efficiently to patients on reuse, dental pulp is as infective as peripheral nerve tissue and a subclinical carrier population for vCJD exists, a self-sustaining vCJD epidemic arising from endodontic surgery is plausible. There are uncertainties about the efficiency of vCJD transmission via endodontic procedures, the vCJD infectivity of dental pulp and the existence of a subclinical infection carrier state. However, even if a self-sustaining epidemic were not possible, clusters of vCJD infections could arise from the use of instruments contaminated with the vCJD agent from endodontic procedures on infected patients. Interactions between this and other routes of secondary transmission, such as blood transfusion and hospital surgery, would make a self-sustaining epidemic more likely.
Potential risk reduction measures
10. Endodontic files and reamers have a limited lifespan, restricting the number of possible secondary transmissions. Improving the effectiveness of procedures used to decontaminate dental instruments would reduce the risk of transmission. Restricting endodontic files and reamers to single use would prevent potential secondary transmission via these instruments. Conclusions
11. A preliminary risk assessment produced by DH suggests that vCJD transmission via endodontic dentistry may, under certain hypothetical but plausible scenarios, be sufficient to sustain a secondary vCJD epidemic. However, there are uncertainties around the data and assumptions underpinning the assessment. Research underway will address some of these uncertainties and allow the risk assessment to be refined. Once the research is complete and / or other data become available, the risks should be reassessed. A watching brief should be maintained.
12. It is unclear whether or not vCJD infectivity can be transmitted via endodontic files and reamers. However, given the plausibility of such a scenario and the large number of procedures undertaken annually, it would be prudent to consider restricting these instruments to single use as a precautionary measure. Since sufficiently rigorous decontamination of these instruments is difficult, single use of these instruments would eliminate this risk, should it exist.
SEAC May 2006
© SEAC 2007
4. Preliminary, unpublished results of research from the Health Protection Agency, aimed at addressing some of the uncertainties in the risk assessments, were reviewed by SEAC (SEAC 97, May 2007). The prion agent used in these studies is closely related to the vCJD agent. This research, using a mouse model, shows that following inoculation of mouse-adapted bovine spongiform encephalopathy (BSE) directly into the gut, infectivity subsequently becomes widespread in tissues of the oral cavity, including dental pulp, salivary glands and gingiva, during the preclinical as well as clinical stage of disease.
5. It is not known how closely the level and distribution of infectivity in the oral cavity of infected mice reflects those of humans infected with vCJD, as there are no comparable data from oral tissues, in particular dental pulp and gingiva, from human subclinical or clinical vCJD cases. Although no abnormal prion protein was found in a study of human dental tissues, including dental pulp, salivary glands and gingiva from vCJD cases22, the relationship between levels of infectivity and abnormal prion protein is unclear23. Infectivity studies underway using the mouse model and oral tissues that are presently available from human vCJD cases will provide some comparable data. On the basis of what is currently known, there is no reason to suppose that the mouse is not a good model for humans in respect to the distribution of infectivity in oral tissues. Furthermore, the new data are consistent with published results from experiments using a hamster scrapie model24.
6. A second set of experiments using the same mouse model showed that non-invasive and transient contact between gingival tissue and fine dental files contaminated with mouse-adapted BSE brain homogenate transmits infection very efficiently. It is not known how efficient gingival transmission would be if dental files were contaminated with infectious oral tissues and then subsequently cleaned and sterilised, a situation which would more closely model human dental practice. Further studies using the mouse model that would be more representative of the human situation, comparing oral tissues with a range of doses of infectivity, cleaned and sterilised files and the kind of tissue contact with instruments that occurs during dentistry, should be considered.
7. SEAC considered that the experiments appear well designed and the conclusions justified and reliable, while recognising that the research is incomplete and confirmatory experiments have yet to be completed. It is recommended that the research be completed, submitted for peer-review and widely disseminated as soon as possible so others can consider the implications. Nevertheless, these preliminary data increase the possibility that some oral tissues of humans infected with vCJD may potentially become infective during the preclinical stage of the disease. In addition, they increase the possibility that infection could potentially be transmitted not only via accidental abrasion of the lingual tonsil or endodontic procedures but a variety of routine dental procedures.
20 Department of Health (2006) Dentistry and vCJD: the implications of a carrier-state for a self-sustaining epidemic. Unpublished. 21 SEAC (2006) Position statement on vCJD and endodontic dentistry.
22 Head et al. (2003) Investigation of PrPres in dental tissues in variant CJD. Br. Dent. J. 195, 339-343. 23 SEAC 90 reserved business minutes.
Implications for transmission risks
11. The new research also suggests that dental procedures involving contact with other oral tissues, including gingiva, may also be capable of transmitting vCJD. In the absence of a detailed risk assessment examining the potential for transmission via all dental procedures, it is not possible to come to firm conclusions about the implications of these findings for transmission of vCJD. However, given the potential for transmission by this route serious consideration should be given to assessing the options for reducing transmission risks such as improving decontamination procedures and practice or the implementation of single use instruments.
12. The size of the potential risk from interactions between the dental and other routes of secondary transmission, such as blood transfusion and hospital surgery, to increase the likelihood of a self-sustaining epidemic is unclear.
13. It is likely to be difficult to distinguish clinical vCJD cases arising from dietary exposure to BSE from secondary transmissions via dental procedures, should they arise, as a large proportion of the population is likely both to have consumed contaminated meat and undergone dentistry. However, an analysis of dental procedures by patient age may provide an indication of the age group in which infections, if they occur, would be most likely to be observed. Should the incidence of clinical vCJD cases in this age group increase significantly, this may provide an indication that secondary transmission via dentistry is occurring. Investigation of the dental work for these cases may provide supporting data. There is no clear evidence, to date, based on surveillance or investigations of clinical vCJD cases, that any vCJD cases have been caused by dental procedures but this possibility cannot be excluded.
14. Preliminary research findings suggest that the potential risk of transmission of vCJD via dental procedures may be greater than previously anticipated. Although this research is incomplete, uses an animal model exposed to relatively high doses of infectivity, and there are no data from infectivity studies on human oral tissues, these findings suggest an increased possibility that vCJD may be relatively efficiently transmitted via a range of dental procedures. Ongoing infectivity studies using human oral tissues and the other studies suggested here will enable more precise assessment of the risks of vCJD transmission through dental procedures.
15. Guidance was issued to dentists earlier this year recommending that endodontic files and reamers be treated as single use which, provided it is adhered to, will remove any risk of a self-sustaining epidemic arising from re-use of these instruments. To minimise risk it is critical that appropriate management and audit is in place, both for NHS and private dentistry.
16. It is also critical that a detailed and comprehensive assessment of the risks of all dental procedures be conducted as a matter of urgency. While taking into account the continuing scientific uncertainties, this will allow a more thorough consideration of the possible public health implications of vCJD transmission via dentistry and the identification of possible additional precautionary risk reduction measures. The assessment will require continued updating as more evidence becomes available on the transmissibility of vCJD by dental routes, and on the prevalence of infection within the population. A DH proposal to convene an expert group that includes dental professionals to expedite such an assessment is welcomed. Given the potential for transmission via dentistry, consideration should be given to the urgent assessment of new decontamination technologies which, if proved robust and effective, could significantly reduce transmission risks.
SEAC June 2007
27 SEAC Epidemiology Subgroup (2006) position statement of the vCJD epidemic.
28 DH (2007) Precautionary advice given to dentists on re-use of instruments
see full text 17 pages ;
SEAC 99th meeting on Friday 14th December 2007
DECEMBER 14, 2007, 10 year Anniversary of my Moms death 'confirmed' from Heidenhain Variant Creutzfeldt Jakob Disease
AS one of them _lay_ folks, one must only ponder ;
"WITH the Nor-98 now documented in five different states so far in the USA in 2007, and with the TWO atypical BSE H-BASE cases in Texas and Alabama, with both scrapie and CWD running rampant in the USA, IS there any concern from SEAC with the rise of sporadic CJD in the USA from ''UNKNOWN PHENOTYPE'', and what concerns if any, in relations to blood donations, surgery, optical, and dental, do you have with these unknown atypical phenotypes in both humans and animals in the USA ???"
"Does it concern SEAC, or is it of no concern to SEAC?"
"Should it concern USA animal and human health officials?"
----- Original Message -----
Sent: Thursday, November 22, 2007 5:39 AM
Subject: QUESTION FOR SEAC
Mr Terry S Singeltary Sr., Bacliff, Texas 77518 USA.
Dear Mr Singeltary,
"Thank you for your e-mail of yesterday with the question for SEAC. I can confirm that this will be asked at the meeting on your behalf and the question and answer will appear in the minutes of the meeting which will be published on the SEAC Internet site."
Archive Number 20071105.3602 Published Date 05-NOV-2007 Subject PRO/AH/EDR> Prion disease update 2007 (07)
PRION DISEASE UPDATE 2007 (07) ****************************** A ProMED-mail post
 USA: National Prion Disease Pathology Surveillance Center Date: June 2007 Source: National Prion Disease Pathology Surveillance Center (USA) [edited]
CJD Cases examined ---------------------- Year / Referrals / Prion disease / Sporadic / Familial / Iatrogenic / vCJD
1996 / 42 / 32 / 26 / 4 / 0 / 0 1997 / 115 / 68 / 57 / 9 / 0 / 0 1998 / 93 / 53 / 45 / 7 / 1 / 0 1999 / 114 / 69 / 61 / 8 / 0 / 0 2000 / 151 / 103 / 89 / 14 / 0 / 0 2001 / 208 / 116 / 106 / 9 / 0 / 0 2002 / 255 / 143 / 118 / 23 / 2 / 0 2003 / 272 / 174 / 132 / 41 / 0 / 0 2004 / 334 / 183 / 157 / 21 / 0 / 1* 2005 / 352 / 195 / 152 / 37 / 1 / 0 2006 / 372 / 186 / 143 / 30 / 0 / 1** 2007 / 120 / 68 / 35 / 7 / 0 / 0 TOTAL / 2428*** / 1390**** / 1121 / 210 / 4 / 2
*Acquired in UK ** Acquired in Saudi Arabia *** Includes 17 inconclusive and 9 pending (1 from 2006, 8 from 2007. **** Includes 17 non-vCJD type unknown (2 from 1996, 2 from 1997, 1 from 2001, 1 from 2003, 4 from 2004, 3 from 2005, 4 from 2006) and 36 type pending (2 from 2005, 8 from 2006, 26 from 2007).
-- Cases are listed based on the year of death when available. If the year of death is not available, the year of sample receipt is used.
-- Referrals: Cases with possible or probable prion disease from which brain tissue or blood in the case of familial disease were submitted.
-- Inconclusive: Cases in which the samples were not sufficient to make a diagnosis.
-- Non-vCJD type unknown are cases in which the tissue submitted was adequate to establish the presence but not the type; in all cases, vCJD could be excluded.
-- Communicated by: Terry S. Singeltary Sr.
[In submitting these data, Terry S. Singeltary Sr. draws attention to the steady increase in the "type unknown" category, which, according to their definition, comprises cases in which vCJD could be excluded. The total of 26 cases for the current year (2007) is disturbing, possibly symptomatic of the circulation of novel agents. Characterization of these agents should be given a high priority. - Mod.CP]
There is a growing number of human CJD cases, and they were presented last week in San Francisco by Luigi Gambatti(?) from his CJD surveillance collection.
He estimates that it may be up to 14 or 15 persons which display selectively SPRPSC and practically no detected RPRPSC proteins.
JOURNAL OF NEUROLOGY
MARCH 26, 2003
RE-Monitoring the occurrence of emerging forms of Creutzfeldt-Jakob
disease in the United States
Email Terry S. Singeltary:
I lost my mother to hvCJD (Heidenhain Variant CJD). I would like to
comment on the CDC's attempts to monitor the occurrence of emerging
forms of CJD. Asante, Collinge et al  have reported that BSE
transmission to the 129-methionine genotype can lead to an alternate
phenotype that is indistinguishable from type 2 PrPSc, the commonest
sporadic CJD. However, CJD and all human TSEs are not reportable
nationally. CJD and all human TSEs must be made reportable in every
state and internationally. I hope that the CDC does not continue to
expect us to still believe that the 85%+ of all CJD cases which are
sporadic are all spontaneous, without route/source. We have many TSEs in
the USA in both animal and man. CWD in deer/elk is spreading rapidly and
CWD does transmit to mink, ferret, cattle, and squirrel monkey by
intracerebral inoculation. With the known incubation periods in other
TSEs, oral transmission studies of CWD may take much longer. Every
victim/family of CJD/TSEs should be asked about route and source of this
agent. To prolong this will only spread the agent and needlessly expose
others. In light of the findings of Asante and Collinge et al, there
should be drastic measures to safeguard the medical and surgical arena
from sporadic CJDs and all human TSEs. I only ponder how many sporadic
CJDs in the USA are type 2 PrPSc?
THE PATHOLOGICAL PROTEIN
Hardcover, 304 pages plus photos and illustrations. ISBN 0-387-95508-9
BY Philip Yam
CHAPTER 14 LAYING ODDS
Answering critics like Terry Singeltary, who feels that the U.S. under- counts CJD, Schonberger conceded that the current surveillance system has errors but stated that most of the errors will be confined to the older population.
doi:10.1016/S1473-3099(03)00715-1 Copyright © 2003 Published by Elsevier Ltd. Newsdesk
Tracking spongiform encephalopathies in North America
Available online 29 July 2003. Volume 3, Issue 8, August 2003, Page 463
“My name is Terry S Singeltary Sr, and I live in Bacliff, Texas. I lost my mom to hvCJD (Heidenhain variant CJD) and have been searching for answers ever since. What I have found is that we have not been told the truth. CWD in deer and elk is a small portion of a much bigger problem." ...
Diagnosis and Reporting of Creutzfeldt-Jakob Disease
Singeltary, Sr et al. JAMA.2001; 285: 733-734.
Like lambs to the slaughter
31 March 2001 Debora MacKenzie Magazine issue 2284
FOUR years ago, Terry Singeltary watched his mother die horribly from a degenerative brain disease. Doctors told him it was Alzheimer's, but Singeltary was suspicious. The diagnosis didn't fit her violent symptoms, and he demanded an autopsy. It showed she had died of sporadic Creutzfeldt-Jakob disease.
Most doctors believe that sCJD is caused by a prion protein deforming by chance into a killer. But Singeltary thinks otherwise. He is one of a number of campaigners who say that some sCJD, like the variant CJD related to BSE, is caused by eating meat from infected animals. Their suspicions have focused on sheep carrying scrapie, a BSE-like disease that is widespread in flocks across Europe and North America.
Now scientists in France have stumbled across new evidence that adds weight to the campaigners' fears. To their complete surprise, the researchers found that one strain of scrapie causes the same brain damage in mice as sCJD.
"This means we cannot rule out that at least some sCJD may be caused by some strains of scrapie," says team member Jean-Philippe Deslys of the French Atomic Energy Commission's medical research laboratory in Fontenay-aux-Roses, south-west of Paris.
Hans Kretschmar of the University of Göttingen, who coordinates CJD surveillance in Germany, is so concerned by the findings that he now wants to trawl back through past sCJD cases to see if any might have been caused by eating infected mutton or lamb. ...
DER SPIEGEL (9/2001) - 24.02.2001 (9397 Zeichen) USA: Loch in der Mauer Die BSE-Angst erreicht Amerika: Trotz strikter Auflagen gelangte in Texas verbotenes Tiermehl ins Rinderfutter - die Kontrollen der Aufsichtsbehörden sind lax. Link auf diesen Artikel im Archiv:
"Its as full of holes as Swiss Cheese" says Terry Singeltary of the FDA regulations. ...
Thu Dec 6, 2007 11:38
FDA IN CRISIS MODE, AMERICAN LIVES AT RISK
FDA SCIENCE AND MISSION AT RISK
2 January 2000
British Medical Journal
U.S. Scientist should be concerned with a CJD epidemic in the U.S., as well
15 November 1999
British Medical Journal
vCJD in the USA * BSE in U.S.
Monitoring the occurrence of emerging forms of Creutzfeldt-Jakob disease in the United States
NOR-98 ATYPICAL SCRAPIE CASES USA
CREUTZFELDT JAKOB DISEASE MAD COW BASE UPDATE USA
Transmissible Mink Encephalopathy TME
CHRONIC WASTING DISEASE
----- Original Message -----
From: Terry S. Singeltary Sr.
To: FREAS@CBER.FDA.GOVCc: email@example.com ; firstname.lastname@example.org
Sent: Wednesday, November 29, 2006 1:24 PM
Subject: TSE advisory committee for the meeting December 15, 2006 [TSSSUBMISSION] November 29, 2006
Greetings FDA, DHH, Dr. Freas, and Dr. Harvey et al,
a kind and warm Holiday Greetings to you all. i kindly wish to submit the following to the TSE advisory committee for the meeting December 15, 2006, about the assessment for potential exposure to vCJD in human plasma-derived antihemophilic factor (FVIII) products manufactured from U.S. plasma donors and related communication material ;
i see the media picked up on this as a 'low risk', from what the gov. agency perceived to be to them;
however, i seem to disagree. from my primitive ciphering, i see it anotherway. this is a huge catastrophic risk. 3 in 160 is 1.9%. so call that 2% which is 1 in 50 or twenty per thousand or 20,000 per million. also, what about the mixed genotypes/mixed susceptibility? what about the silent carriers that donated tainted blood? what about the sporadic CJDs of UNKNOWN strain or phenotype? this risk assessment is just more BSe to me. just another in a long line of ...
Greetings again Dr. Freas et al at FDA,
THIS was like closing the barn door after the mad cows got loose. not only the red cross, but the FDA has failed the public in protecting them from the TSE aka madcow agent. TSE agent i.e. bse, base, cwd, scrapie, tme, and any sub strains thereof. we do not know if these strains will or have transmitted to humans as subclinical TSE or clinical disease, and we do not know if they have or will transmit second, third, forth passage via friendly fire i.e. multiple potential routes via medical, surgical, pharmaceutical etc. IF you remember correctly Dr. Freas et al, i called this long ago, almost 6 years ago ;
PDF]Freas, William TSS SUBMISSION
Terry S. Singeltary Sr. [email@example.com] Monday, January 08, 200l 3:03 PM freas ...Freas, William From: Terry S. Singeltary Sr. [firstname.lastname@example.org] Sent: Monday, January 08,200l 3:03 PM
Subject: CJD/BSE (aka madcow) Human/Animal TSE?s--U.S.--Submission
To Scientific Advisors and Consultants Staff January 2001 Meeting (short version)
Greetings again Dr. Freas and Committee Members,
I wish to submit the following information to the Scientific Advisors and Consultants Staff 2001 Advisory Committee (short version). I understand the reason of having to shorten my submission, but only hope that you add it to a copy of the long version, for members to take and read at their pleasure, (if cost is problem, bill me, address below). So when they realize some time in the near future of the 'real' risks i speak of from human/animal TSEs and blood/surgical products.
I am beginning to think that the endless attempt to track down and ban, potential victims from known BSE Countries from giving blood will be futile. You would have to ban everyone on the Globe eventually? AS well, I think we MUST ACT SWIFTLY to find blood test for TSE's, whether it be blood test, urine test, eyelid test, anything at whatever cost, we need a test FAST. DO NOT let the incubation time period of these TSEs fool you. To think of Scrapie as the prime agent to compare CJD, but yet overlook the Louping-ill vaccine event in 1930's of which 1000's of sheep where infected by scrapie from a vaccine made of scrapie infected sheep brains, would be foolish. I acquired this full text version of the event which was recorded in the Annual Congress of 1946 National Vet. Med. Ass. of Great Britain and Ireland. From the BVA and the URL is posted in my (long version). ...
see full text ;
vCJD case study highlights blood transfusion risk
[Docket No. 03-025IFA] FSIS Prohibition of the Use of Specified Risk Materials for Human Food and Requirement for the Disposition of Non-Ambulatory Disabled Cattle
[Docket No. FSIS-2006-0011] FSIS Harvard Risk Assessment of Bovine Spongiform Encephalopathy (BSE)
Docket No. 03-080-1 -- USDA ISSUES PROPOSED RULE TO ALLOW LIVE ANIMAL IMPORTS FROM CANADA
Subject: Importation of Whole Cuts of Boneless Beef from Japan [Docket No. 05-004-1] RIN 0579-AB93 TSS SUBMISSION Date: August 24, 2005 at 2:47 pm PST August 24, 2005
Importation of Whole Cuts of Boneless Beef from Japan [Docket No. 05-004-1] RIN 0579-AB93 TSS SUBMISSION
Greetings APHIS ET AL,
My name is Terry S. Singeltary Sr.
I would kindly like to comment on [Docket No. 05-004-1] RIN 0579-AB93 ;
THE USA is in a most unique situation, one of unknown circumstances with human and animal TSE. THE USA has the most documented TSE in different species to date, with substrains growing in those species (BSE/BASE in cattle and CWD in deer and elk, there is evidence here with different strains), and we know that sheep scrapie has over 20 strains of the typical scrapie with atypical scrapie documented and also BSE is very likely to have passed to sheep. all of which have been rendered and fed back to animals for human and animal consumption, a frightening scenario. WE do not know the outcome, and to play with human life around the globe with the very likely TSE tainted products from the USA, in my opinion is like playing Russian roulette, of long duration, with potential long and enduring consequences, of which once done, cannot be undone. These are the facts as I have come to know through daily and extensive research of TSE over 9 years, since 12/14/97. I do not pretend to have all the answers, but i do know to continue to believe in the ukbsenvcjd only theory of transmission to humans of only this one strain from only this one TSE from only this one part of the globe, will only lead to further failures, and needless exposure to humans from all strains of TSE, and possibly many more needless deaths from TSE via a multitude of proven routes and sources via many studies with primates and rodents and other species.
MY personal belief, since you ask, is that not only the Canadian border, but the USA border, and the Mexican border should be sealed up tighter than a drum for exporting there TSE tainted products, until a validated, 100% sensitive test is available, and all animals for human and animal consumption are tested. all we are doing is the exact same thing the UK did with there mad cow poisoning when they exported it all over the globe, all the while knowing what they were doing. this BSE MRR policy is nothing more than a legal tool to do just exactly what the UK did, thanks to the OIE and GW, it's legal now. and they executed Saddam for poisoning ???
go figure. ...
Terry S. Singeltary Sr. P.O. Box 42 Bacliff, Texas USA 77518
Comment Submitted Comment Receipt
Thank you. Your comment on Document ID: APHIS-2006-0041-0001 has been sent. Comment Tracking Number: APHIS-2006-0041-DRAFT-0028
Attachments: C:\My Music\My Documents\APHIS-2006-0041_January 28.doc
If you wish to retain a copy of the receipt, use the following link to print a copy for your files. Print
THE only difference between the UK poisoning the globe, and the USA, it is now legal with GWs and OIEs BSE MRR policy ;
IT's O.K. to poison 3rd world countries ;
On 20 February 1990, Dr Pickles wrote to Ms Verity (APS/CMO). Dr Pickles minute included the following: 1. Mr Meldrum is arguing that MAFF have already taken all the necessary and responsible steps to warn importing countries of the BSE dangers in UK meat and bone meal. Yet the action taken so far overseas suggest the message has not got through, or where it has this has been late. The first nation that woke up to the danger did so a year after our own feed ban. It seems even now several EC countries neither ban our imports or the general feeding of ruminant protein. It also seems the OIE and CVO have yet to inform the rest of the world. 2. I do not see how this can be claimed to be responsible. We do not need an expert group of the Scientific Veterinary Committee to tell us British meat and bone meal is unsafe for ruminants. I fail to understand why this cannot be tackled from the British end which seems to be the only sure way of doing it, preferably by banning exports. As CMO says in his letter of 3 January surely it is short sighted for us to risk being seen in future as having been responsible for the introduction of BSE to the food chain in other countries. 
OLD DOCKET SUBMISSION TSS
Docket No, 04-047-l Regulatory Identification No. (RIN) 091O-AF46 NEW BSE SAFEGUARDS (comment submission)
Docket No. 2003N-0312 Animal Feed Safety System [TSS SUBMISSION]
Docket Management Docket: 02N-0273 - Substances Prohibited From Use in
Animal Food or Feed; Animal Proteins Prohibited in Ruminant Feed
Comment Number: EC -10
Accepted - Volume 2
PDF]Freas, William TSS SUBMISSION
File Format: PDF/Adobe Acrobat -
Page 1. J Freas, William From: Sent: To: Subject: Terry S. Singeltary
Sr. [email@example.com] Monday, January 08,200l 3:03 PM freas ...
Asante/Collinge et al, that BSE transmission to the 129-methionine
genotype can lead to an alternate phenotype that is indistinguishable
from type 2 PrPSc, the commonest _sporadic_ CJD;
Docket Management Docket: 96N-0417 - Current Good Manufacturing Practice in Manufacturing, Packing, or Holding Dietary Ingredients a Comment Number: EC -2 Accepted - Volume 7
[PDF] Appendices to PL107-9 Inter-agency Working Group Final Report 1-1 File Format: PDF/Adobe Acrobat - View as HTML Agent, Weapons of Mass Destruction Operations Unit Federal Bureau of those who provided comments in response to Docket No. ... Meager 8/18/01 Terry S. Singeltary Sr ...
Docket No. 2003N-0312 Animal Feed Safety System [TSS SUBMISSION TO DOCKET 2003N-0312]
# Docket No: 02-088-1 RE-Agricultural Bioterrorism Protection Act of 2002; [TSS SUBMISSION ON POTENTIAL FOR BSE/TSE & FMD 'SUITCASE BOMBS'] - TSS 1/27/03 (0)
Docket: 02N-0276 - Bioterrorism Preparedness; Registration of Food Facilities, Section 305 Comment Number: EC-254 [TSS SUBMISSION]
Dockets Entered On October 2, 2003 Table of Contents, Docket #, Title, 1978N-0301,
OTC External Analgesic Drug Products, ... EMC 7, Terry S. Singeltary Sr. Vol #: 1, ...
Daily Dockets Entered on 02/05/03
DOCKETS ENTERED on 2/5/03. ... EMC 4 Terry S. Singeltary Sr. Vol#: 2. ... Vol#: 1.
03N-0009 Federal Preemption of State & Local Medical Device Requireme. ...
Docket: 02N-0370 - Neurological Devices; Classification of Human Dura Mater
Comment Number: EC -1
Accepted - Volume 1
Daily Dockets - 04/10/03
... 00D-1662 Use of Xenotransplantation Products in Humans. EMC 98 Terry S. Singeltary Sr. Vol#: 3. 01F ...
- 05-20-2003 - Cached
2003D-0186 Guidance for Industry: Use of Material From Deer and Elk In Animal Feed
EMC 1 Terry S. Singeltary Sr. Vol #:1
01N-0423 Substances Prohibited from use in animal food/Feed Ruminant
EMC 1 Terry S. Singeltary Sr. Vol#: 3