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For MRJ, "Test Accuracy"

Mike

Well-known member
"This inconclusive result does not mean we have found a new case of BSE. Inconclusive results are a normal component of most screening tests, which are designed to be extremely sensitive so they will detect any sample that could possibly be positive. In addition, this animal did not enter the human food chain nor the animal feed chain."

The statement above by John Clifford, Chief Veterinary Medical Officer for the USDA speaks volumes on the "Sensitivity" of screening tests.

Screening tests are in fact designed to be extremely oversensitive so that no positive animal can pass through it without detection.

Read it again, and again. Let it soak in..............................

Link: http://www.usda.gov/wps/portal/usdahome?contentidonly=true&contentid=2006/03/0080.xml
 

mrj

Well-known member
Mike, where did you see anything I posted which indicated failure to understand there are INCONCLUSIVE tests? I have seen that press release and fully understand it.

What about the animal, the final test of which had to be sent to England to get the accurate information, and that lab tech person stated it was a very difficult case to diagnose? Do we NOW have that test available in the USA?

I want to know if there are accurate tests that indicate either "this animal or this tissue tests positive for BSE" or "this animal or tissue shows NO presence of BSE".

Further, as I've indicated in the past, we need to know how many 'inconclusives' are found, how many of those are further tested, and how many must leave the productive uses (both food and non-food uses) chains.

And, we need more research into real cause(s) and effect of BSE, and solutions for the problems, if in fact, there are real problems, including the marketing problem.

mrj
 

Mike

Well-known member
mrj said:
Mike, where did you see anything I posted which indicated failure to understand there are INCONCLUSIVE tests? I have seen that press release and fully understand it.

What about the animal, the final test of which had to be sent to England to get the accurate information, and that lab tech person stated it was a very difficult case to diagnose? Do we NOW have that test available in the USA?

I want to know if there are accurate tests that indicate either "this animal or this tissue tests positive for BSE" or "this animal or tissue shows NO presence of BSE".

Further, as I've indicated in the past, we need to know how many 'inconclusives' are found, how many of those are further tested, and how many must leave the productive uses (both food and non-food uses) chains.

And, we need more research into real cause(s) and effect of BSE, and solutions for the problems, if in fact, there are real problems, including the marketing problem.

mrj

You are trying very hard to not understand.

It didn't HAVE to be sent to England!

The Prionics test pronounced the cow positive before the sample went to England and the USDA's "Experimental" version of the IHC did not.

Immediately after England announced it as positive, the USDA decided to use both tests as confirmatories.

The Prionics test is 100% sensitive with 100% specificity.

Inconclusives are attributed to poor sample collections and are incinerated as are positives, as I understand.

The USDA's "Inconclusives" were arguably actual positives that were not confirmed using proper methods.
 

Mike

Well-known member
mrj said:
Where can I find the verification by a third party for your statement?

mrj

Which statement specifically?

Everything in my statement has been posted here at an earlier date.

Is it up to me to educate you? :???:

Performance
PrioSTRIP® passed both the EU and the Swiss evaluation studies with flying colors. In 2004 the EU organized a field study of BSE tests on over 10,000 samples from healthy slaughtered animals and 200 samples of BSE-affected animals. The test scored 100% sensitivity and 100% specificity; all samples were identified correctly. Furthermore, the mean signal-to-cutoff ratio of negative samples was extremely low (0.009) and all negative values were in the same low signal-to-cutoff ratio range. Both of these factors reduce the risk of incorrect initial reactive. This demonstrates that the Prionics®-Check PrioSTRIP combines speed with reliability. In February 2005 the test was officially approved by the European Commission.
 

Sandhusker

Well-known member
Mike, "Is it up to me to educate you?"

When the only places she gets her information from is NCBA/USDA/AMI, somebody needs to step in and help her out! :lol:
 

mrj

Well-known member
Mike, I just don't trust your biases.

Sandhusker, it isn't nice to lie!

Both of you: I don't have a staff to do my foot-work or feed the cowboys around here.......so don't have endless hours to play on the computer, as you appear to.

My sources are more varied than S. claims. Fortunately, I don't have to rely on his favorite source, which appears to be R-CALF and/or their alter-egos and/or their apparent "sugar daddy" groups OCM/LMA.

mrj
 

Mike

Well-known member
mrj said:
Mike, I just don't trust your biases.

Sandhusker, it isn't nice to lie!

Both of you: I don't have a staff to do my foot-work or feed the cowboys around here.......so don't have endless hours to play on the computer, as you appear to.

My sources are more varied than S. claims. Fortunately, I don't have to rely on his favorite source, which appears to be R-CALF and/or their alter-egos and/or their apparent "sugar daddy" groups OCM/LMA.

mrj

You ask for accuracy of tests, I give it to you and you whine about biases and time not available?

Your tunnel vision must be awesome. :roll:
 

mrj

Well-known member
Mike, fine and dandy........the tests you admire are approved by the European Commission, so you say. Does that mean they areapproved and used world-wide, including in the USA?

Re. your comment that the Prionics test pronounced the cow positive before the sample went to England, didn't we read that the tests were "inconclusive", and further, that the British stated that it was a difficult case and results were not strongly positive?

If, as you state, that sample didn't HAVE to be sent to England, why was it sent?

Sandhusker, some of you boys obviously seem content to get your information from R-CALF/LMA/OCM or their approved 'sources', yet you challenge my sources, all of which you cannot possibly know???. I'll stack mine sources up against yours for accuracy any day. My sources include Ag colleges and universities and other science based/related sources.

mrj
 

bse-tester

Well-known member
It has been mentioned that the only reason that the Brits even stated what they stated regarding the sample (difficult case) was because the quality of the sample had apparently deteriorated so much by the time it arrived that it became difficult to seperate the necessary units from the homogenate which was infused with decomposing stata and some rather ugly mix was forming in the sample prior to its arrival in the UK. Of course, the VLA at Weybridge, Surrey, UK, could have and perhaps should have, requested additional samples.

Hmmmmmmmmmm, it appears that we are talking tests again??? Ron.
 

Mike

Well-known member
Mike, fine and dandy........the tests you admire are approved by the European Commission, so you say. Does that mean they areapproved and used world-wide, including in the USA?

Yes.


Re. your comment that the Prionics test pronounced the cow positive before the sample went to England, didn't we read that the tests were "inconclusive", and further, that the British stated that it was a difficult case and results were not strongly positive?

Don't you remember past yesterday? The Bio-Rad test was positive. Which is an actual "Inconclusive" because it is a screening test. The many experimental "USDA Gold Standard" ( :roll: ) IHC's were negative....

Phyllis stepped in and proved it positive with the Prionics. The USDA didn't believe it and sent it to England. The USDA now uses the Prionics as a confirmatory test...........................................

If you don't want the answers you are getting...............

Quit asking questions. If you won't listen to them you are wasting my time. :mad:
 
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