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for reader (the second)

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Well-known member
Feb 10, 2005
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can you enlighten me on what this means? it's from an e-mail sent by one of our prov. livestock specialists. i guess there are different standards to the gold level tests.

In Sandy Russel's report on the Alberta Beef Industry Conference, Dr. Joyce VanDonkersgoed (AB Verified Beef program)was asked "If our industries are so linked why are we finding BSE cases and the US is not even though they have tested a higher number of animals?` Her comment was the "gold standard" tests (final confirmatory tests) in Canada and the US are different. She said the US version uses a test with 1 micoclonal antibody, compared to Canada's test which uses 15 microclonal antibodies. This could account for the difference.

The CFIA was asked to explain why Canada and the US would use different standards and why this has not been a issue in the debate over Canada being a source of BSE and the US is clean according to some of the opposition to the opening of the US border to Canadian cattle.

Following is the reply:

-----Original Message-----
From: Penny Greenwood [mailto:p[email protected]]
Sent: Wednesday, March 16, 2005 1:58 PM
To: [email protected]
Cc: Nancy Lalonde; Marlene Longtin; <
Subject: Re: Testing for BSE- Canada and US proceedures: WEB RESPONSE / RÉPONSE DU WEB ID:2005/3-603

The international standard setting body for animal health and zoosanitary status is the OIE. This body sets the standards for conditions for countries to claim a particular disease status (eg. free) for specific diseases, stipulates conditions for trade in affected commodities (animals, semen, meat, etc), surveillance and also for diagnostic methodologies used to detect these diseases.

A member country could certainly debate the appropriateness of another member country's testing if they were not following the recommendations made in the OIE code and associated documentation.

Both the US and Canada utilize immunohistochemistry (IHC) as the gold standard test for BSE. In response to your comments regarding the antibodies used in this test by each country I have cut and pasted the relevant paragraph of Chapter 2.3.13 of the OIE Manual of Diagnostic Tests and Vaccines for Terrestrial Animals as it discusses the standardization of the IHC test for BSE:

"In conjunction with, or even as an alternative to, the histopathological evaluation of medulla sections is the use of IHC to detect PrPres accumulation in formalin-fixed, paraffin-embedded material (47, 94). Several protocols have been applied successfully to the IHC detection of PrP for the diagnosis of BSE (44, 47, 54, 94). Harmonisation toward a fully validated standardised routine diagnostic IHC method is desirable. However, it is likely that only the general principles can be prescribed, with precise methods being determined by each individual laboratory. A European Commission (EC) funded collaboration among European laboratories, which addressed the need for harmonisation of diagnostic methods, concluded that the total standardisation of methods was difficult and possibly unnecessary. Local conditions will always dictate a degree of inter-laboratory variation, and each method should be optimised for use with the standard tissues and common reagents (such as water) used locally. Historically there has also been a dependence on 'in-house' polyclonal antibodies, but the increase in commercially available monoclonal antibodies has reduced this variation significantly. It is much more important to achieve a standardised output, as monitored by participation in QA exercises, and by comparison with the results of a standardised model method."

The CFIA is aware of differences in the testing of BSE in Canada and the US. In dialogues with the US, the CFIA continues to detail the reagents that we use and believe are appropriate to use in the diagnosis of the United States. Nonetheless, the decision on the reagents used in the laboratory diagnosis of BSE is ultimately the choice of the individual member countries.


Dr. Penny Greenwood

Senior Staff Veterinarian

Disease Control

Canadian Food Inspection Agency

59 Camelot Drive

Nepean ON K1A 0Y9

(613) 225-2342 ext 4612

(613) 228-6630 fx

[email protected]
From what I get out of it. The US is testing for BSE but not using the best science available, which increases the likelihood of BSE being missed in the US herd. Of course, since it is not a worldwide standard test, there is nothing forcing the US to do any more than do a BSE test of some kind, even if it is flawed. The whole issue is irrelevant anyway as long as the SRM's are removed. We are testing for prevalence, not because it is a food safety issue.
The whole issue is irrelevant anyway as long as the SRM's are removed. We are testing for prevalence, not because it is a food safety issue.

i don't think it's irrelevant if the us is arguing for a safer bse status on the basis of an inferior or flawed test. that gives them an advantage in foreign markets as well as justifying their halfhearted effort to open the border to canadian cattle. if the us gold standard test is less thorough than what other countries are using, it's probably not a big secret outside the us.
When a man becomes so engrossed in his subject, the color of his vision,and the clouds in his mind, it will sometimes obscure his path to a fair and just opinion.

The way I see it, and I could be wrong. Is that Canada is testing the dead and downer cattle. This will only show the prevalence in their herds. The US is testing suspect cows that might be slaughtered and enter the food chain. This too does little more then determine the prevalence of the disease. This testing is only being done to convince the consumer of the safety of beef. What I would like to see is for more to be done to assure we do not get an epidenic here like there is in Europe. Nothing has been done here to really determine the source. Maybe this will be done when we have more knowledge. If it is spread by feed, with the things in place now, in just a few years the cows that might have become infected will be out of our herds. Do what we must until that happens.

Could you inquire about what I will now state: (you are already well connected to the material)

To my knowledge, this testing for BSE, according to the CFIA letter you posted, is detecting PrPres, yes?

This can include the normal and healthy PrPc that is bonded to its copper glyco terminus, as well as the PrPsc which is screwed up because of rogue metal attachments. Both are protease resistant. At any time, there would have to be many PrPc (res) present in the sample as this is a step in their anatomical function, to transport copper back into the nerve cell.

Why are the tests not specific for PrPsc prions? There can be all kinds of malformed proteins in our body and just because a few are located that are resistant to protinase K, this doesn't mean the animal has BSE.

This is why further examination is necessary, and actual examination of the brain tissue to for spongiform holes is required.

If the initial rapid tests are screening for PrPres (15 varieties). Perhaps you could ask, what the 15 various antibodies are picking out, and how are these prions different from one and other; and what is the single USA one finding. This could be very important to understand the main question, which appears to be, why has the USDA not found any cases???
kathy - i posted this hoping to learn more what it meant myself. i guess what i will do is forward it to cfia and ask if one of their vets can explain the implications of using the two different types of tests. i addressed the question to reader (the second) because she seems to have investigated more of the research side of this. anyways, i'll get it to cfia and see if they answer.
This person, Sandy Russel, who reported that this was asked at the conference... who is she and where can I contact her?

That was one heck of a good question.

Ask the CFIA to be very specific and detailed. We may be ranchers, that doesn't mean we can't desipher their complicated technical data.

Every time I ask questions of DEFRA, CFIA, OIE, prion research companies, prion research doctors - before they answer they want to know "who are you and who do you work for/ or represent?"

As far as I am concerned, just give me the bloody answers and don't hold back on the technical jargen, I can handle it and we will eventually find researchers involved in other disease realms that will become curious as to why things are touted as infectious in the BSE realm, but not in their specific area of research. EG. - the company Neurochem check out their webpage.
And thank-you Kathy for your educated view and no bull, on the subject. Maybe you should hang out here a little more!

Like reading the posts above this article does not make me feel the USDA has made the best decisions.
Mike said:

Like reading the posts above this article does not make me feel the USDA has made the best decisions.

Reminds me of everytime I flew in a military aircraft knowing that it was built by the lowest bidder- not a feeling of great confidence......
:)Just wondering oldtimer, do you or any of the other more informed Rcalf members ever take this kind of stuff to your extremely uninformed leadership? It might be important information for Bullshit Bill, and the gang to consider before mouthing off about Canada and it's BSE problems - not?