TAFS INTERNATIONAL FORUM FOR TRANSMISSIBLE ANIMAL DISEASES AND FOOD SAFETY a non-profit Swiss Foundation(February 2009)

TAFS1 Position Paper on Specified Risk Materials

출처 : http://www.tafsforum.org/tse.html

Intestine – the distal ileum was expected to be infectious by extrapolation from sheep scrapie, and this was subsequently confirmed for BSE in experimentally infected cattle especially in the early stages of incubation. Logic suggests that it must also be infectious in naturally infected cattle in the early stages of incubation. This infectivity was particularly associated with Peyer’s patches(29), collections of lymphoid tissue that form a first line of defence against infection through the intestinal wall. This result has not been replicated in naturally infected cattle, although immunostaining methods have shown the presence of abnormal prion protein in the nervous plexuses of the intestine. This discrepancy is considered to be most probably due to the fact that the Peyer’s patches regress as cattle reach maturity, and consequently reduce the likelihood of finding any infectivity that may remain. The majority of infected cows die of clinical BSE at five to seven years of age, after the Peyer’s patches have regressed. Nevertheless, the positive immunostaining of the nervous plexuses, which extend throughout the intestine, does justify continued listing of intestine as SRM while there is a danger that cattle will have been exposed to BSE(10,25).

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[각주]

10. EFSA (2007). – Opinion of the Scientific Panel on Biological Hazards on a request from the European Commission on quantitative histological studies and the re-assessment of the BSE related risk of bovine intestines after processing into natural sausage casings. The EFSA Journal. 464: 1-14.
http://www.efsa.europa.eu/cs/BlobServer/Scientific_Opinion/biohaz_op_ej464_bovine_casings_en,4.pdf?ssbinary=true

25. SSC – Scientific Steering Committee (2002) SSC opinion of 4-5 April 2002 on safe sourcing of small ruminant materials (with special reference to the safety with regard to BSE risks of sheep intestines and casings). http://europa.eu.int/comm/food/fs/sc/ssc/out281_en.pdf

29. Terry, L.A., Marsh, S., Ryder, S.J., Hawkins, S.A.C., Wells, G.A.H., Spencer, Y.I. (2003). Detection of disease specific PrP in Peyer’s patches of the distal ileum of cattle orally exposed to the BSE agent. Vet. Rec. 152: 387-392.