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Bovine adapted transmissible mink encephalopathy is similar to L-BSE after passage through sheep with the VRQ/VRQ genotype but not VRQ/ARQ

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SUNDAY, OCTOBER 11, 2020

Bovine adapted transmissible mink encephalopathy is similar to L-BSE after passage through sheep with the VRQ/VRQ genotype but not VRQ/ARQ

https://transmissible-mink-encephal...020/10/bovine-adapted-transmissible-mink.html



August 1988

Evidence That Transmissible Mink Encephalopathy Results From Feeding Infected Cattle

https://web.archive.org/web/20090506002258/http://www.bseinquiry.gov.uk/files/mb/m09/tab05.pdf

Evidence That Transmissible Mink Encephalopathy Results from Feeding Infected Cattle Over the next 8-10 weeks, approximately 40% of all the adult mink on the farm died from TME. snip... The rancher was a ''dead stock'' feeder using mostly (>95%) downer or dead dairy cattle...

https://web.archive.org/web/20090506002258/http://www.bseinquiry.gov.uk/files/mb/m09/tab05.pdf

https://web.archive.org/web/20090506001031/http://www.bseinquiry.gov.uk/files/mb/m09a/tab01.pdf

https://web.archive.org/web/2009050...einquiry.gov.uk/files/yb/1987/06/10004001.pdf

NOW, in 1979, it was proven that indeed U.S. scrapie strain that was transmitted to U.S. cattle, did NOT produce a Transmissible Spongiform Encephalopathy (TSE) like the U.K. B.S.E., but a TSE unlike the U.K. B.S.E. SO what does all this tell us? it tells me that there is a possibility that a strain of mad cow disease was circulating in the U.S.A. long, long, before originally thought, only left to be ignored, while incubating and spreading.

3.57 The experiment which might have determined whether BSE and scrapie were caused by the same agent (ie, the feeding of natural scrapie to cattle) was never undertaken in the UK. It was, however, performed in the USA in 1979, when it was shown that cattle inoculated with the scrapie agent endemic in the flock of Suffolk sheep at the United States Department of Agriculture in Mission, Texas, developed a TSE quite unlike BSE.339 The findings of the initial transmission, though not of the clinical or neurohistological examination, were communicated in October 1988 to Dr Watson, Director of the CVL, following a visit by Dr Wrathall, one of the project leaders in the Pathology Department of the CVL, to the United States Department of Agriculture.340 The results were not published at this point, since the attempted transmission to mice from the experimental cow brain had been inconclusive. The results of the clinical and histological differences between scrapie-affected sheep and cattle were published in 1995. Similar studies in which cattle were inoculated intracerebrally with scrapie inocula derived from a number of scrapie-affected sheep of different breeds and from different States, were carried out at the US National Animal Disease Centre.341 The results, published in 1994, showed that this source of scrapie agent, though pathogenic for cattle, did not produce the same clinical signs of brain lesions characteristic of BSE.

3.58 There are several possible reasons why the experiment was not performed in the UK. It had been recommended by Sir Richard Southwood (Chairman of the Working Party on Bovine Spongiform Encephalopathy) in his letter to the Permanent Secretary of MAFF, Mr (now Sir) Derek Andrews, on 21 June 1988,342 though it was not specifically recommended in the Working Party Report or indeed in the Tyrrell Committee Report (details of the Southwood Working Party and the Tyrell Committee can be found in vol. 4: The Southwood Working Party, 1988–89 and vol. 11: Scientists after Southwood respectively). The direct inoculation of scrapie into calves was given low priority, because of its high cost and because it was known that it had already taken place in the USA.343 It was also felt that the results of such an experiment would be hard to interpret. While a negative result would be informative, a positive result would need to demonstrate that when scrapie was transmitted to cattle, the disease which developed in cattle was the same as BSE.344 Given the large number of strains of scrapie and the possibility that BSE was one of them, it would be necessary to transmit every scrapie strain to cattle separately, to test the hypothesis properly. Such an experiment would be expensive. Secondly, as measures to control the epidemic took hold, the need for the experiment from the policy viewpoint was not considered so urgent. It was felt that the results would be mainly of academic interest.345

3.59 Nevertheless, from the first demonstration of transmissibility of BSE in 1988, the possibility of differences in the transmission properties of BSE and scrapie was clear. Scrapie was transmissible to hamsters, but by 1988 attempts to transmit BSE to hamsters had failed. Subsequent findings increased that possibility.

337 Fraser, H., Bruce, M., Chree, A., McConnell, I. and Wells, G. (1992) Transmission of Bovine Spongiform Encephalopathy and Scrapie to Mice, Journal of General Virology, 73, 1891–7; Bruce, M., Chree, A., McConnell, I., Foster, J., Pearson, G. and Fraser, H. (1994) Transmission of Bovine Spongiform Encephalopathy and Scrapie to Mice: Strain Variation and the Species Barrier, Philosophical Transactions of the Royal Society of London, Series B, Biological Sciences, 343, 405–11 338 Bruce, M., Will, R., Ironside, J., McConell, I., Drummond, D., Suttie, A., McCordie, L., Chree, A., Hope, J., Birkett, C., Cousens, S., Fraser, H. and Bostock, C. (1997) Transmissions to Mice Indicate that ‘New Variant’ CJD is Caused by the BSE Agent, Nature, 389, 498–501 339 Clark, W., Hourrigan, J. and Hadlow, W. (1995) Encephalopathy in Cattle Experimentally Infected with the Scrapie Agent, American Journal of Veterinary Research, 56, 606–12 340 YB88/10.00/1.1 341 Cutlip, R., Miller, J., Race, R., Jenny, A., Katz, J., Lehmkuhl, H., Debey, B. and Robinson, M. (1994) Intracerebral Transmission of Scrapie to Cattle, Journal of Infectious Diseases, 169, 814–20 342 YB88/6.21/1.2 343 YB88/11.17/2.4

https://web.archive.org/web/20090505200149/http://www.bseinquiry.gov.uk/pdf/volume2/Chapter3.pdf

http://bse-atypical.blogspot.com/2008/08/bovine-spongiform-encephalopathy-mad.html

31

Appendix I VISIT TO USA - OR A E WRATHALL — INFO ON BSE AND SCRAPIE

Dr Clark lately of the scrapie Research Unit, Mission Texas has

successfully transmitted ovine and caprine scrapie to cattle. The

experimental results have not been published but there are plans to do

this. This work was initiated in 1978. A summary of it is:-



http://web.archive.org/web/20060307063531/http://www.bseinquiry.gov.uk/files/mb/m11b/tab01.pdf

VISIT TO USA - DR AE WRATHALL - INFO ON BSE AND SCRAPIE

1. Dr. Clark lately of the Scrapie Research Unit, Mission Texas has successfully transmitted ovine & caprine Scrapie to cattle. The experimental results have not been published but there are plans to do this. This work was initiated in 1978. A summary of it is;

snip...see handwritten notes from this here;

http://www.bseinquiry.gov.uk/files/yb/1988/10/00001001.pdf

https://web.archive.org/web/2009050...einquiry.gov.uk/files/yb/1988/10/00001001.pdf

IN CONFIDENCE

Perceptions of an unconventional slow virus diseases of animals in the U.S.A. G A H Wells

Report of a Visit to the USA April-May 1989

http://webarchive.nationalarchives....www.bseinquiry.gov.uk/files/mb/m11b/tab01.pdf

http://bseusa.blogspot.com/2018/

Thursday, June 09, 2016

Scrapie Field Trial Experiments Mission, Texas, The Moore Air Force Base Scrapie Experiment 1964

How Did CWD Get Way Down In Medina County, Texas?

Confucius ponders...

see full text ;

http://web.archive.org/web/20030513212324/http://www.bseinquiry.gov.uk/files/mb/m08b/tab64.pdf

snip...see full text;

SUNDAY, OCTOBER 11, 2020

Bovine adapted transmissible mink encephalopathy is similar to L-BSE after passage through sheep with the VRQ/VRQ genotype but not VRQ/ARQ

https://transmissible-mink-encephal...020/10/bovine-adapted-transmissible-mink.html

wasted days and wasted nights...FREDDY FENDER

terry
 

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