The paper presents a practical approach to assessing the risks of exposure to the infective agents from transmissible spongiform encephalopathies. Current data on the infectivity of bovine tissues have been reviewed and values for use in risk assessment studies proposed for the infectivityof central nervous system and other tissues, the development of infectivity through the incubation period and the cattle-human species barrier. A study to assess the risk of exposure to BSE infectivity in cattle disposed of during the 2001 foot and mouth epidemic in the UK by burning in pyres or burial is used to illustrate the application of TSE risk assessment and the way in which it can be used as an input to decision making.
Get full access to this article
View all access options for this article.
References
1.
Wells GAH, Scott AC, Johnson CT, Gunning RF, Hanoek RD, Jeffrey M, Dawson M, Bradley R.A novel progressive spongiform encephalopathy in cattle. Veterinary Record1987; 121: 419-420.
2.
DNV. Compendium of five Reports: a) Overview of Risks from BSE via Environmental Pathways, b) Thruxted Mill Rendering Plant-Risk Assessment of Waste Water Disposal Options, c) Risks from Burning Rendered Products from the Over Thirty Month Scheme in Power Stations, d) Risks from Disposing of BSE Infected Cattle in Animal Carcase Incinerators, e) Assessment of Risk from BSE Carcases in Landfills. Report to Environment Agency, Det Norske Veritas C7243 (June 1997).
3.
Cummins EJ, Grace PM, McDonnell KP, Ward SM.Predictive modelling and risk assessment of BSE: a review. Journal of Risk Research2001; 4: 251-274.
4.
Kimberlin RH.Bovine spongiform encephalopathy and public health: some problems and solutions in assessing the risks. In: Court L, Dodet B, eds. Transmissible Spongiform Encephalopathies: Prion Diseases. Paris: Elsevier, 1996: pp. 487-502.
5.
Gale P, Young C, Stanfield G, Oakes D.Development of a risk assessment for BSE in the aquatic environment. Journal of Applied Microbiology1998; 84: 467-477.
6.
Gale P, Stanfield G.Towards a quantitative risk assessment for BSE in the aquatic environment. Journal of Applied Microbiology2001; 91: 563-569.
7.
and 11 (3): 18-30.
8.
Evatt BL.Prions and haemophilia: assessment of risk. Haemophilia1998; 4: 628-633.
9.
DNV. Assessment of the Risk of Exposure to vCJD Infectivity in Blood and Blood Products. Report 8288, Rev. 4, Det Norske Veritas (January 1999).
10.
DNV. Risk Assessment of Exposure to vCJD Infectivity in Blood and Blood Products. Report 716108, Rev. 3, Det Norske Veritas (February 2003).
11.
Kamphues J, Zentek J, Oberthur RC, Flachowsky G, Coenen M.Risk assessment for animal derived feedstuffs as vectors for bovine spongiform encephalopathy (BSE) in Germany. Part 1: Comparative risk assessment for animal derived feedstuffs. Deutsche Tierarztliche Wochenschrift2001; 108: 283-290.
12.
Zentek J, Oberthur RC, Kamphues J, Kreienbrock L, Flachowsky G, Coenen M.Risk assessment for animal derived feedstuffs as vectors for bovine spongiform encephalopathy (BSE) in Germany. Part 2: Compounded feed as a vector for bovine spongiform encephalopathy (BSE) in Germany. Deutsche Tierarztliche Wochenschrift2002; 109: 43-51.
13.
Schudel AA, Carrillo BJ, Weber EL, Viera JB, Gimeno EJ, vanGelderen C, Ulloa E, Nader A, Cane BG, Kimberlin RH.Risk assessment and surveillance for bovine spongiform encephalopathy (BSE) in Argentina. Preventive Veterinary Medicine1996; 25: 271-284.
14.
SSC. EC, Scientific Steering Committee. Final Opinion: Geographical Risk of Bovine Spongiform Encephalopathy. Adopted by the SSC at its meeting of 6 July 2000.
15.
SSC. EC, Scientific Steering Committee. Opinion: Geographical BSE Risk (GBR) and its evolution over time in the European Union Member States. Adopted by the SSC at its meeting of 21=22 February 2002.
16.
Cohen JT, Duggar K, Gray GM, Kreindel S, Abdelrahman H, HabteMariam T, Oryang D, Tameru B.Evaluation of the Potential for Bovine Spongiform Encephalopathy in the United States. Report from the Havard Center for Risk Analysis to the USDA (2001).
17.
ISGRA. Quantified risk analysis in the process industries. The Chemical Engineer1982; 385: 385-386, 389-389.
18.
Pitblado R, Turney R.Risk Assessment in the Process Industries. Rugby: Institute of Chemical Engineers, 1996.
19.
The Royal Society. Risk Assessment. Report of a Royal Society Study Group. London: The Royal Society, 1983.
20.
The Royal Society. Risk: Analysis, Perception and Management. Report of a Royal Society Study Group. London: The Royal Society, 1992.
21.
DETR. Guidelines for Environmental Risk Assessment and Management; www.defra.gov.uk/environment/eramguide/index.htm (2000).
McLean AR, Bostock CJ.Scrapie infections initiated at varying doses: an analysis of 117 titration experiments. Philosophical Transactions of the Royal Society, London, Series B2000; 355: 1043-1050.
24.
Newby H.Risk analysis and risk perception: the social limits of technological change. IChemE Jubilee Lecture. Trans IChemE B1997; 75: 133-137.
25.
Bruce ME, Will RG, Ironside JW, McConnell I, Drummond D, Suttie A, McCardle L, Chree A, Hope J, Birkett C, Cousens S, Fraser H, Bostock CJ.Transmissions to mice indicate that new variant CJD is caused by the BSE agent. Nature1997; 389: 498-501.
26.
Collinge J, Hill AF, Desbruslais M, Joiner S, Sidle KCL, Gowland I.The same prion strain causes vCJD and BSE. Nature1987; 389: 448-450.
27.
Donnelly CA, Ferguson NM, Ghani AC, Woolhouse MEJ, Watt CJ, Anderson RM.The epidemiology of BSE in cattle herds in Great Britain. I. Epidemiological processes, demography of cattle and approaches to control by culling. Philosophical Transactions of the Royal Society, London, Series B1997; 352: 781-801.
28.
Anderson RM, Donnelly CA, Ferguson NM, Woolhouse MEJ, Watt CJ, Udy HJ, MaWhinney S, Dunstan SP, Southwood TRE, Wilesmith JW, Ryan JBM, Hoinville LJ, Hillerton JE, Austin AR, Wells GAH.Transmission dynamics and epidemiology of BSE in British cattle. Nature1996; 382: 779-788.
29.
Ferguson NM, Donnelly CA, Woolhouse MEJ, Anderson RM.The epidemiology of BSE in cattle herds in Great Britain. II. Model construction and analysis of transmission dynamics. Philosophical Transactions of the Royal Society, London, Series B1997; 352: 803-838.
30.
Donnelly CA, Ferguson NM, Ghani AC, Anderson RM.Implications of BSE infection screening data for the scale of the British BSE epidemic and current European infection levels. Proceedings of the Royal Society, London B2002; 269: 2179-2190.
31.
SSC. EC, Scientific Steering Committee. Opinion: Oral Exposure to Humans of the BSE Agent: Infective Dose and Species Barrier. Adopted by the SSC at its meeting on the 13-14 April 2000.
32.
Huntly PJ, Comer PJ, Geertsma RE, Schreuder BEC, de Koijer AA, van Bruggen M, Osterhaus ADME, van der Poel WHM.Assessment of risk to public health from exposure to BSE infectivity from the Rendac Bergum rendering plant, RIVM Report 244920002=2002, National Institute for Public Health and the Environment, The Netherlands; www.rivm.nl (2002).
33.
DNV.Risk of Exposure to BSE Infectivity in UK Sheep. DNV Report no. C100110, Version 3 (28 June 2002).
34.
Wells GAH, Hawkins SAC, Green RB, Austin AR, Dexter I, Spencer YI, Chaplin MJ, Stack MJ, Dawson M.Preliminary observations on the pathogenesis of experimental bovine spongiform encephalopathy (BSE): an update. Veterinary Record1998; 144: 292-294.
35.
SSC. EC, Scientific Steering Committee. Opinion: TSE Infectivity Distribution in Ruminant Tissues (State of knowledge, December 2001). Adopted by the SSC at its meeting on 10-11 January 2002.
36.
SEAC. Statement on Infectivity in Bovine Tonsil. SEAC Statement 2002=1, www.seac.gov.uk; 2002.
37.
SSC. EC, Scientific Steering Committee. Opinion and Report: Assessment of the Human BSE risk posed by bovine vertebral column including Dorsal Root Ganglia. Adopted by the SSC at its meeting of 16 May 2002.
38.
Beekes M, Baldauf E, Diringer H.Sequential appearance and accumulation of pathogenic markers in the central nervous system of hamsters orally infected with scrapie. Journal of General Virology1996; 77: 1925-1934.
39.
Raymond GJ, Hope J, Kocisko DA, Priola SA, Raymond LD, Bossers A, Ironside J, Will RG, Chen SG, Petersen RB, Gambetti P, Rubenstein R, Smits MA, Lansbury PT, Caughey B.Molecular assessment of the potential transmissibilities of BSE and scrapie to humans. Nature1997; 388: 285-288.
40.
Ghani AC, Ferguson NM, Donnelly CA, Anderson RM.Factors determining the pattern of the variant Creutzfeldt-Jacob disease epidemic in the UK. Proceedings of the Royal Society, London: B2003; 270: 689-698.
41.
Andrews NJ, Farrington CP, Ward HJT, Cousens SN, Smith PG, Molesworth AM, Knight RSG, Ironside JW, Will RG.Deaths from variant Creutzfeldt-Jacob disease in the UK. Lancet2003; 361: 751-752.
42.
DNV. Assessment of Risk due to BSE Infectivity from Disposal of Cattle due to FMD. Report 716018, Rev. 2, Det Norske Veritas (1 April 2001).
DEFRA. Bovine Spongiform Encephalopathy in Great Britain, A Progress Report December 2001; www.defra.gov.uk/animalh/bse/bse-publications/progress/dec01/order.pdf (2002).
45.
DNV. Risk Assessment of SRM Incinerators. Report 1000089, Rev. 3, Det Norske Veritas (March 2001).
46.
Taylor DM, Woodgate SL, Atkinson MJ.Inactivation of the bovine spongiform encephalopathy agent by rendering procedures. Veterinary Record1995; 137: 605-610.
47.
SEAC. Report of Special Spongiform Encephalopathy Working Group Meeting-24 May 2001-FMD Disposal Sites; www.seac.gov.uk (2001).
