SEAC Scientific Steering Committee on TSE Prion
SEAC PUBLICATIONS
89th meeting on Thursday 22nd September 2005
- SEAC Reviews;
- 1997 (PDF 2.37 MB) &
- http://web.archive.org/web/20091010132911/http://www.seac.gov.uk/publicats/Review1997.pdf
- The 2008 review (PDF 100KB)
- The response to the 2008 review (PDF 21KB)
SEAC Statements
Use of SEAC opinions
- Statement on options relating to modification of the total feed ban
(60 KB) . - SEAC Sheep Subgroup report of 2007 meeting (67 KB)
- Statement on the potential human health risk from changes to classical scrapie controls (41 KB)
- Position statement - New forms of Bovine Spongiform Encephalopathy
Position statement - Prevalence of subclinical variant creutzfeldt - Jakob disease infections
- Position statement - Prevalence of subclinical variant creutzfeldt - Jakob disease infections (60KB)
Position statement - Food Standards Agency atypical scrapie contingency plan
Position statement vCJD and dentistry
- SEAC position statement vCJD and dentistry.
Sheep Subgroup Statement
- SEAC Sheep Subgroup Statement (97 KB).
Position statement on the vCJD epidemic
- SEAC epidemiology subgroup position statement on the vCJD epidemic.
Evaluation criteria for ante mortem diagnostic tests for subclinical vCJD
Position statement on methods to evaluate decontamination technologies for surgical instruments
Position statement on TSE infectivity in blood
Position statement on vCJD and Endodontic dentistry
- This position statement summarises SEAC's consideration of the potential for transmission of vCJD via endodontic dentistry.
Position statement on atypical scrapie
- SEAC sheep subgroup position statement (81 KB) has also been published.
Position statement on the vCJD epidemic
- SEAC response to the SEAC epidemiology subgroup position statement on the vCJD.
Hypothesis that BSE originated from a human TSE
- This position statement summarises SEAC's discussion of a hypothesis that BSE was originally derived from a human TSE.
Summary of SEAC discussion of vertebral column: age at which specified risk material
- This statement provides a summary of SEAC's discussion on review of an assessment of the BSE exposure risk from vertebral column.
Early phase of vCJD infection in blood transfusion recipients
- Position statement on Early phase of vCJD infection in blood transfusion recipients (31 KB)
Potential for maternal transmission of vCJD
- This position statement (34 KB) summarises SEAC's consideration of the potential for transmission of vCJD from mother to child.
Chronic wasting disease in UK deer
- This position statement summarises SEAC's consideration of the possible public and animal health implications of chronic wasting disease in UK deer. The committee also considered the possibility that BSE may be present in UK deer.
SEAC Sheep Subgroup's views
- SEAC Sheep Subgroup's views (October 2004) on future operation of the National Scrapie Plan
Blood transfusion-associated infection with vCJD.
- This statement provides a summary of SEAC’s discussion on the second presumed case.
New Chair of SEAC announced
- The appointment of Professor Chris Higgins as the new Chair for the Spongiform Encephalopathy Advisory Committee (SEAC) (14 KB) has been announced
Susceptibility of different genotypes in sheep to experimental BSE .
- This statement (25 KB) represents the opinion of a specialist sub-group of SEAC which met on 11th December 2002 to consider this specific issue. The statement was ratified by SEAC on February 11th 2003.
Infectivity in Bovine Tonsil
We were asked by the Food Standards Agency (FSA) to review preliminary results from a long-term study of experimental BSE in cattle.
This research is funded by the Food Standards Agency and is being carried out by researchers from the Veterinary Laboratory Agency. This research forms part of a large long-term experiment, which is ongoing. However, the Food Standards Agency and the researchers have released these preliminary results so that any appropriate public health action can be considered.
We have reviewed the results of this ongoing research and have prepared a summary of our advice. We make recommendations regarding further information required to conduct a risk assessment.
This statement (17 KB) has been released with the full agreement of both the Food Standards Agency and the researchers. A press release issued by the FSA on 17 October 2002 is also available.
(17 KB) has been released with the full agreement of both the Food Standards Agency and the researchers. A press release issued by the FSA on 17 October 2002 is also available.Previous Statements |
| Review of the theoretical risk of BSE in sheep (23/5/97) |
| Maternal transmission of BSE - Report of Epidemiology sub committee (16/4/97) |
| Maternal transmission of BSE (29/7/96) |
| Experimental transmission of BSE to sheep and risk of exposure to BSE through feed (10/7/96) |
| Handling of waste material from cattle (7/6/96) |
| New variant of CJD - Risk Assessment (24/3/96) |
2003 
(168 KB)
(168 KB)This is SEAC's seventh annual report and covers the terms of reference, structure, membership and operations of the Committee. The report also summarises the Committee’s work on CJD and public health, food safety and the protection of animal health and environmental issues. Details of the work of its sub-committees are also included, together with the texts of all statements and advice. The latter covers the statements on infectivity in bovine tonsil, susceptibility of different genotypes in sheep to experimental BSE and unconfirmed ELISA positive samples in the UK national scrapie survey of cull sheep.
2002 (160 KB)
(160 KB)This is SEAC's sixth annual report and covers the terms of reference, structure, membership and operations of the Committee. The report also summarises the Committee’s work on CJD and public health, food safety and the protection of animal health and environmental issues. Details of the work of its sub-committees are also included, together with the texts of all statements and advice. The latter covers the Public Consultation on Death Certification and Coroner’s services and statements on infectivity in bovine Tonsil and susceptibility of different genotypes in sheep to experimental BSE.
2001-2002 (187 KB)
(187 KB)This is SEAC's fifth annual report and covers the terms of reference, structure, membership and operations of the Committee. The report also summarises the Committee’s work on CJD and public health, food safety and the protection of animal health and environmental issues. Details of the work of its sub-committees are also included, together with the texts of all statements and advice. The latter covers the use of ophthalmic fitting sets and other ophthalmic devices and an interim report on the over thirty month rule.
1999-2000 (245 KB)
(245 KB)List of Scientific Papers supplied to SEAC members by the secretariat
2008 | January  (42 KB) | April (45 KB) |
2007 | ||
2006 | ||
2005 | ||
2004 | ||
2003 | ||
2002 | None available | |
2001 | 29th Nov 2000 - 28th Feb 2001 | |
2000 | 16th Feb - 11th May | 18th July - 29th Sept |
| 12th May - 17th July | 30th Sept - 28 Nov | |
Annual Reports
2008 (PDF 100KB)
2007 (PDF 241 KB)
2006 (PDF 239 KB)
2005 (PDF 239 KB)
2004 (PDF 186 KB)
In BSE in cattle there is early infection of the ileum and tonsils, followed by later
infection of the CNS, dorsal root ganglia and trigeminal ganglia. Emerging Japanese
data suggests that there may be infectivity in peripheral nerves in clinical BSE.
http://www.seac.gov.uk/papers/tseroadmap05.pdf
infection of the CNS, dorsal root ganglia and trigeminal ganglia. Emerging Japanese
data suggests that there may be infectivity in peripheral nerves in clinical BSE.
http://www.seac.gov.uk/papers/tseroadmap05.pdf
http://web.archive.org/web/20091010133408/http://www.seac.gov.uk/papers/tseroadmap05.pdf
TSE Roadmap - Scientific Opinions Final Version 6 September 2005
Page
1.1.7. SSC Opinion on Chronic Wasting Disease and Tissues that might carry a
risk for Human and Animal Feed Chains, 6-7 March 2003
Theoretical risk for prion transmission to humans consuming products of CWD
affected cervids of all ages cannot be excluded.
Similarly, transmission risk to domestic animals cannot be excluded4.
Early and widespread involvement of tissues in CWD-infected animals does not allow
definition of SRM list, nor to define age limits. Insufficient data to define exclusions or
amendment of any SRM rule on the basis of relative genetic resistance to infection.
Important to be certain that no risk of transmission of CWD from North America to EU
through trade in live cervids or their products.
No scientific data that CWD is present in countries outside North America (except
single import to Korea). However further European surveillance necessary.
1.1.8. SSC Opinion on BSE Risk of Autonomic Nervous System, 6-7 March 2003
Infectivity found in vagus nerve and sympathetic mesenteric ganglia of experimental
animals (mice/hamsters) and sheep infected with scrapie. Experimental data from
cattle insufficient, but infectivity in these tissues has not been shown in cattle5 other
than the inconsistent presence of disease-related PrP in the myenteric plexus
(network of nerve fibres throughout muscle of digestive tract) of cattle during the
Unclear whether scrapie models are applicable to pathogenesis of BSE. Cannot
exclude possibility that other autonomic NS structures carry infectivity in BSEinfected
Recommend collection of tissue samples appropriate to improving understanding role
of PNS and particularly the autonomic NS, from field cases and cattle in
4 See also 1.1.2. Experimental Transmission of Chronic Wasting Disease Agent from
Mule Deer to Cattle by Intracerebral Route, Hamir et al.2005, J Vet Diagn Invest
5 The Japanese Institute for Animal Health has detected Western Blot positives in
peripheral nerves in a fallen bovine. Further results are expected in late 2005/early
TSE Roadmap - Scientific Opinions Final Version 6 September 2005
Page 8 of 18
9 EC FAIR CT97 3308 Project
10 Refers to April 2004 SSC Opinion on oral exposure of humans to BSE agent:
infective dose and species barrier. This refers to small amount of tissue that can
contain an infective dose of BSE agent for cattle and sheep ( < 1 gram of
homogenised brain tissue). 2005 data suggests 1mg is sufficient to infect calves.
SNIP...
TSE Roadmap - Scientific Opinions Final Version 6 September 2005
Page 9 of 18
2.3.2. Unpublished Data from VLA, 2005
Unpublished data from a pressure rendering study indicates that BSE infectivity can
survive in tallow recovered by centrifugation and tallow recovered by solvent
extraction.
http://www.seac.gov.uk/papers/tseroadmap05-app3.pdf
TSE Roadmap - Scientific Opinions Final Version 6 September 2005
Page
1.1.7. SSC Opinion on Chronic Wasting Disease and Tissues that might carry a
risk for Human and Animal Feed Chains, 6-7 March 2003
Theoretical risk for prion transmission to humans consuming products of CWD
affected cervids of all ages cannot be excluded.
Similarly, transmission risk to domestic animals cannot be excluded4.
Early and widespread involvement of tissues in CWD-infected animals does not allow
definition of SRM list, nor to define age limits. Insufficient data to define exclusions or
amendment of any SRM rule on the basis of relative genetic resistance to infection.
Important to be certain that no risk of transmission of CWD from North America to EU
through trade in live cervids or their products.
No scientific data that CWD is present in countries outside North America (except
single import to Korea). However further European surveillance necessary.
1.1.8. SSC Opinion on BSE Risk of Autonomic Nervous System, 6-7 March 2003
Infectivity found in vagus nerve and sympathetic mesenteric ganglia of experimental
animals (mice/hamsters) and sheep infected with scrapie. Experimental data from
cattle insufficient, but infectivity in these tissues has not been shown in cattle5 other
than the inconsistent presence of disease-related PrP in the myenteric plexus
(network of nerve fibres throughout muscle of digestive tract) of cattle during the
Unclear whether scrapie models are applicable to pathogenesis of BSE. Cannot
exclude possibility that other autonomic NS structures carry infectivity in BSEinfected
Recommend collection of tissue samples appropriate to improving understanding role
of PNS and particularly the autonomic NS, from field cases and cattle in
4 See also 1.1.2. Experimental Transmission of Chronic Wasting Disease Agent from
Mule Deer to Cattle by Intracerebral Route, Hamir et al.2005, J Vet Diagn Invest
5 The Japanese Institute for Animal Health has detected Western Blot positives in
peripheral nerves in a fallen bovine. Further results are expected in late 2005/early
TSE Roadmap - Scientific Opinions Final Version 6 September 2005
Page 8 of 18
9 EC FAIR CT97 3308 Project
10 Refers to April 2004 SSC Opinion on oral exposure of humans to BSE agent:
infective dose and species barrier. This refers to small amount of tissue that can
contain an infective dose of BSE agent for cattle and sheep ( < 1 gram of
homogenised brain tissue). 2005 data suggests 1mg is sufficient to infect calves.
SNIP...
TSE Roadmap - Scientific Opinions Final Version 6 September 2005
Page 9 of 18
2.3.2. Unpublished Data from VLA, 2005
Unpublished data from a pressure rendering study indicates that BSE infectivity can
survive in tallow recovered by centrifugation and tallow recovered by solvent
extraction.
http://www.seac.gov.uk/papers/tseroadmap05-app3.pdf
http://web.archive.org/web/20091010133412/http://www.seac.gov.uk/papers/tseroadmap05-app3.pdf
Appendix 4 - A Summary of Opinions from the Spongiform
Encephalopathy Advisory Committee (SEAC)
http://www.seac.gov.uk/papers/tseroadmap05-app4.pdf
Appendix 4 - A Summary of Opinions from the Spongiform
Encephalopathy Advisory Committee (SEAC)
http://www.seac.gov.uk/papers/tseroadmap05-app4.pdf
SEAC 99
SEAC 1997 TO 2003
TAFS
BSE GBR 2007
Terry S. Singeltary Sr.
