Published Date: 2005-06-11 23:50:00
Subject: PRO/AH/EDR> BSE, bovine - USA: susp. (02): tests
Archive Number: 20050611.1626
BSE, BOVINE � USA: SUSPECTED (02): TESTS
A ProMED-mail post
ProMED-mail, a program of the
International Society for Infectious Diseases
Date: Sat, 11 Jun 2005
From: "Mary Marshall" <firstname.lastname@example.org>
Source: Web Cast Audio: U.S. Agriculture Officials To Provide
Update On BSE Surveillance Testing - Requires Windows
Transcript of Tele-News Conference with Agriculture Secretary Mike Johanns and
Dr. John Clifford, Chief Veterinary Officer, Animal Plant Health Inspection
Regarding Further Analysis of BSE Inconclusive Test Results Washington, D.C.
Release No. 0207.05
Contact: USDA Press Office (202)720-4623
10 June 2005 [edited]
MR. ED LOYD: "Good evening, everyone, and thank you for joining us late on a
Friday evening. I certainly appreciate your getting on with us on such short
notice for an update of our BSE surveillance. Just so you know, our format
tonight, Agriculture Secretary Mike Johanns is going to make a brief
introductory statement, followed by Dr. John Clifford, the chief veterinary
officer of the APHIS, the Animal Plant Health Inspection Service, who will go
into some more technical background.
DR. CLIFFORD: "Thank you, Mr. Secretary. And thanks everyone for being on the
"Since the USDA enhanced surveillance program for BSE began in June 2004 more
than 375 000 animals from the targeted cattle population have been tested for
BSE using a rapid test. 3 of these animals tested inconclusive and were
subsequently subjected to the immunohistochemistry (IHC) testing. The IHC is
an internationally recognized confirmatory test for BSE. All 3 inconclusive
samples tested negative using the IHC test.
"As the Secretary said earlier this week, USDA's Office of Inspector General
which has been partnering with APHIS, FSIS and ARS, the Agriculture Research
Service, by impartially reviewing BSE-related activities and making
recommendations for improvement, recommended that all 3 of these samples be
subjected to a 2nd internationally recognized confirmatory test, the Western
"We received final results a short time ago... Of the 3 samples 2 were
negative, but the 3rd came back reactive on that test.
"Because of the conflicting results on the IHC and Western
Blot test, a sample from this animal will be sent to the
OIE recognized reference laboratory for BSE in Weybridge,
England. USDA will also be conducting further testing
which will take several days to complete.
"After we receive additional test results on this animal,
we will determine what further steps need to be taken and
what changes if any are warranted in our surveillance
MR. LOYD: "With that, Operator, we would open this up to
REPORTER: "Yes, good evening. This is Peter Shinn from the
National Association of Farm Broadcasters.
"Mr. Secretary, I don't mean to ask a difficult question,
but it just immediately comes to mind. What exactly
happened in terms of how could you have gotten it not
right the first time? And what's the difference between
the IHC and the Western Blot? "
SEC. JOHANNS: "Yeah. I'll ask Dr. Clifford to get in. It's not really a
question of not getting it right. Both tests are accepted by the OIE. Both
tests are accepted under the standard. So it's not a question of getting it
right. All of the protocols were followed. We had the positive and the rapid
response test, the IHC test was applied according to the protocols, and that
is the test that has been used in the United States.
"And so it's not a situation where you've got one test that isn't accepted and
one that is. They both are accepted. There are differences in the tests, and
I'll let Dr. Clifford explain that. And maybe, Dr. Clifford, you can even
explain just what this test showed and how you went about getting through the
DR. CLIFFORD: "Yes, we're confident in the results of actually both of these
tests. The IHC was negative for this sample. Actually the Western Blot test,
if you go back to the December  cow that was found from Canada, the
Western Blot that was run on that particular sample we used one milligram of
tissue to run that test and it was found to be a very strong positive.
"In order to find a positive in this particular case with this Western Blot,
they had to enhance or enrich it, which basically means you're concentrating
the abnormal protein. So they had to use 20 times the amount. You would have
to use about 20 times the amount of tissue for this to determine to be a
positive or reactive on the Western Blot versus the one that was discovered in
December  in the state of Washington.
"In addition, there are definite differences between these 2 tests. The IHC is
internationally recognized, and why we chose that for our enhanced
surveillance program is because that particular test does 2 things. It allows
you to visualize the anatomic location where the lesions are most likely to be
found which is the obex [a specific region of the brain. � Mod.JW]. At the
same time it uses a staining technique on the prions, on abnormal prions in
the tissue in that location....
"In the Western Blot case, it's actually a homogenate of a sample of brain
tissue that is centrifuged and they concentrate the prion protein and then
they use a protease to destroy the normal protein, leaving the abnormal
protein present. And then basically that is run through a gel-type separation
using specific antibodies that will give you bands. And they look at those
bands and the molecular weight of those bands to determine the outcome of that
"So this test would actually be referred to as a weak
positive test in this case for the Western Blot, and as a
result of that and the unusualness of this case it's going
to require additional testing before we can confirm one
way or another whether this is truly BSE or not.
"What we mean by "weak positive," is going back to the original case. It
required and enrichment of these and a greater amount of normal tissue in
order to enhance this outcome. So in order to find the abnormal protein
present you had to use more material and concentrate it."
OPERATOR: "The next question will come from Joe Pelka
(sp). Your line is open.
REPORTER: "Hi. Good evening, gentlemen. I actually have
three questions. I think I can state them succinctly.
First of all, why did the IG ask for a retest in this
case? What do you expect they'll do differently at
Weybridge that they do from Ames, Iowa, in the IHC
testing? And which cow of the 3 r which animal of the
3 that had the earlier positives are we looking at
SEC. JOHANNS: "I'll answer the first one just as best as I
can, and then Doctor, I'll just queue you up that I'll ask
you to answer the final 2.
"The IG has been looking at the surveillance. As you know,
we've tested now 375,000 animals, and Secretary Veneman
wanted to be sure that we were touching the right places--
regions of the country and etcetera to make sure that when
that surveillance was done we were satisfied that we got a
good surveillance of the herd.
"Again, keep in mind that was a surveillance effort; it
was never portrayed to be a food safety approach.
"In that effort I believe that the IG decided just to make
sure that all the bases were touched that this additional
testing should be done. So go ahead, Doctor."
DR. CLIFFORD: " The reason we're sending this to Weybridge is because we feel
this is an unusual case, and we'd like to have the assistance of an
internationally recognized laboratory for BSE.
"The inconclusive that we're referring to here is the one that we gave
notification of in November of 2004. I think it was actually 15 Nov 2004. With
regards to the OIG's recommendation, I think that recommendation was based
upon a strong reaction on the biorad test and the negative IHC, and in order
for us to try to resolve those discrepancies that have been raised relative to
REPORTER: "The November case, was that the Texas cow? If it was -"
SEC. JOHANNS: "You know, Elizabeth, I don't believe the USDA ever talked about
location." [But see previous ProMED post referenced below. � Mod.JW]
REPORTER: "I presume when you start doing trace back though for this animal
you will be then talking about the location?"
SEC. JOHANNS: "You know, I haven't even gotten that far down the road. I just
wanted to get the information out there as quickly as we had it. So."
REPORTER: "And we appreciate that, especially those of us who don't publish
"A further question, at the time of that test I talked to
a lot of people internationally and actually spoke to the
scientist who developed the immunohistochemistry test, and
he said while his test was state of the art when it was
first developed he now considers it as he put it more art
than science. And so I'm wondering, is USDA considering
switching to one of the newer tests, say the one that
Prusinger's Lab has created, something that's got a low
false positive but is perhaps a more sensitive test
because Europe thinks we've kind of outgrown the
SEC. JOHANNS: "Yes. You talk about the curiosity of
timing; it just so happened that today I was touring our
Ames laboratory facility in Ames, Iowa. And that had been
set up well before this was an issue, and I just wanted to
see how they were doing there. And I talked to many of the
scientists that are involved in our BSE research, and I
talked about the tests. And I probed very extensively
about both tests being accepted under OIE standards.
"I believe at the risk of talking for scientists that
you'd get a pretty lively debate about what test is best,
under what circumstances is it best.
"I do know this, that the IHC test is recognized by the
OIE. It's an accepted test. It's a test that we have
employed and we're not alone. Other parts of the world do.
"We would never make a decision about changing protocol in
a knee-jerk sort of way. We would certainly want to debate
that. We would want to get a lot of good scientific
analysis. So it's not something that we would do just
very, very quickly. It's something I'd want very, very
cautious, careful consideration about because there are
some who say, 'No the IHC is where you want to be.'
"So like I said, at the risk of talking for scientists I
think you could get a pretty lively debate on your
DR. CLIFFORD: "I just would like to add one thing, Mr.
Secretary, or a couple of things. Again, to reiterate, we
do not, we have not confirmed a case of BSE in the U.S. at
this time. We're going to do further analysis and study on
"I'd also like to state for the audience, there is such a
thing in Europe that is called "atypical BSE" about which
there's a lot of information and data that is still needed
out there. And in those particular cases, you have in some
cases; you had where IHC has been negative and a Western
Blot been positive.
"In addition with regards to the epidemiology, we have already done some
preliminary epidemiology back when the 1st inconclusive was announced, and
we'll be ready to perform that as necessary."
OPERATOR: "The next question comes from Libby Quaid. Your line is open."
REPORTER: "Thank you. Could you go into a little bit more
on what test you expect will now be performed and when you
expect to know for sure whether this was a positive or a
DR. CLIFFORD: "Actually what I'd like to do is to provide
that information -- our scientists are working in the
Agriculture Research Service and APHIS in our National
Veterinary Services Lab, and they'll also be discussing
this with the scientists at Weybridge, and they'll be
developing a protocol early next week and procedures for
OPERATOR: "The next question comes from Ken Root. Your line is open."
REPORTER: "Yes. Mr. Secretary, was this a native-born U.S. cow?"
SEC. JOHANNS: "That dates back to before I got to the USDA. Doctor, do you
know if that's been released?"
DR. CLIFFORD: "Actually, Mr. Secretary, it has not. What I can say though is
that at this time we would have no information that it was an imported animal;
also that the animal was an aged animal. It was getting up in age and was a
beef breed. That's what we're willing to release at this time."
OPERATOR: "Next question comes from Dan Goldstein. Your line is open."
REPORTER: " Two questions, one for Dr. Clifford and one for the Secretary. Mr.
Secretary, first of all, does this somewhat do you think may shake the
confidence of the international community, one, in the ability of the Ames
Laboratory and, 2, also the efficacy of the IHC test?
"And then also for Dr. Clifford, what does this mean in terms of the
protocols? Will you now have to go back and perhaps test more animals with
Western Blot tests?"
SEC. JOHANNS: "Let me address the question about the Ames
Laboratory, and I'm sure the doctor will want to offer a
"One of the things we are very, very proud of is that Ames
laboratory. They do great work there, and again I remind
everybody that the IHC test is an internationally accepted
test. And that comes from the OIE, and like I said even
amongst scientists you would get debate about the test.
"But it is an internationally accepted test. It was done
according to protocol. It was properly done and produced
negative results as the doctor explained.
"In terms of the confidence of the international
community, I believe they look to us as leaders. Not only
are we aggressive when it comes to this disease; we quite
honestly don't leave any stone unturned in terms of our
efforts to make sure that we're proceeding along the right
"As the doctor pointed out, this is an aged animal. Our
discussions with Japan have related to 20-month animals as
you know. Our discussions with Korea have related to
30-month animals, and the rule relative to Canada or the
Minimal Risk Rule in general I should say relates to
animals under 30 months and meat product under 30 months.
"So I really don't believe this has any impact on our
international trading partners. We'll be working with them
to get information in their hands and make sure that they
understand the situation. But again just because of what
we're talking about here and the age of the animal, we've
got a vast difference between what this is about and what
we're working with them about.
DR. CLIFFORD: "I agree wholeheartedly. Interationally our National Veterinary
Services Lab is recognized and well respected, and this doesn't put any dent
in their armor. They have run the IHC flawlessly, and we're confident in every
result that's resulted from that IHC.
"We're confident in the result of the IHC with this particular animal. As I'd
indicated earlier, and actually the ARS [Agricultural Research Service]
scientists as well as our own because this had to be enriched this wouldn't
have been found [sic] � this particular case would have missed the type
testing we did exactly on the December cow in Canada. It was the IHC and the
Western Blot both in those cases that were found to be positive.
"We have also discussed this particular issue with
international scientists, and I think they have complete
confidence in our program while they also recognize and
would recommend that this one particular animal because of
the unusualness of this case they feel that it should have
been run also against the Western Blot."
OPERATOR: "The next question comes from Tom Stever (sp). Your line is open."
REPORTER: "How frequently has the Western Blot test been used? And also what
makes you think that this will not affect the ongoing efforts to reopen the
borders to U.S. beef in Japan and Korea?"
SEC. JOHANNS: "Again, the doctor points out that this is
an aged beef animal. What we are working with in terms of
Canada as you know is 30 months and under. What we are
working with Japan, because of a concession made in the
negotiations, is 20 months and under, and then Korea 30
months and under.
"And again in terms of our firewalls that are in place,
removal of specified risk material, the extensive
surveillance that we have done, our diligence in the
process of testing, I really do believe that this should
not have any impact on the discussions that we are having
with those countries. If anything, it should illustrate to
them the diligence by which we pursue the safety of our
feed supply and the safety of our supply of food for human
"The other thing I do want to mention is, again I point
out that our firewall has worked here. This animal did not
enter the food supply or the feed supply. There are a
number of inter-related firewalls that we have in place,
and again we have a prime example tonight that they work
and this animal did not enter the food or feed supply.
DR. CLIFFORD: " Actually both of these tests are used extensively
internationally, and it will vary from country to country as to which test
they choose or whether they use both tests in some cases. And in most cases
countries would not use both though, except under certain circumstances or
REPORTER: "Hi, there. Beth Gorham from the Canadian Press Wire Service. Thanks
for taking my question.
"Mr. Secretary, I understand that you think that this
isn't going to affect talks with international partners,
but given the timing of this and I'm not quite clear -- I
know the protocols are being developed next week, but, A,
is there an answer on how long this will take? And B,
given the fact that the appeal is scheduled to go ahead on
13 Jul  in Seattle, are you worried about the impact as
far as the judicial proceedings are concerned?"
SEC. JOHANNS: "You know, I am really not. And let me
explain to you why. I believe that you will have the
entire cattle industry over the next few days and the
folks involved in processing beef and serving beef to
customers recognize and talk very publicly about what
we've talked about tonight. And that is that the firewalls
we have in place do work.
"We did not have an animal that entered the feed or food
chain. All of the protocols were followed. The laboratory
in Ames meticulously followed the step-by-step process,
came up with a negative, and I just think you're going to
have the industry say, hey, what we see is that the USDA
firewalls are working, they're getting the job done for
"And again as you know, Canada really follows the same
approach that we do. So I just don't anticipate an issue
there, and again I don't anticipate a problem with our
trading partners. They'll want to know what the issues are
and what we have done, and we'll provide them with that
"One of the things about this call tonight is, we want to
assure them and to assure the public that what we're doing
here is transparent. I had these results just barely 10
minutes before we got on the line to visit with you. So I
think that's very important.
SEC. JOHANNS: "Doctor, if you might -- and I don't want to
extend this longer than necessary, but it might be good
for a quick refresher on the significance of the rule
specifying 30 months and under and in Japan's case 20
months and under. Do you know what I'm driving at?
DR. CLIFFORD: "With regard to the SRM [Specific Risk Material. � Mod.JW]
removal, yes. Basically the animals under 30 months of age, you know with
regards to SRM removal we remove the tonsils and small intestines, and over 30
months of age animals we remove the spinal cord, the small intestines, as well
as tonsils, eyeballs, the brain tissue, and the dorsal root ganglia. Those are
the tissues that are removed in order to protect the human health in this
OPERATOR: "The next question comes from Tom Brand. Your line is open.
REPORTER: "Good evening. Mr. Secretary, as we've been on this call here this
evening I was actually with a group of some cattle producers and have been
relaying some information along to them... They're interested in why we upped
the sample amount to such, the 20 times, in order to get that positive? ...
DR. CLIFFORD: "When you talk about the enrichment of the sample that's
something that is allowed with regards to that test and the protocol in order
to determine if there's low levels of abnormal protein present. And that's a
technique that has been probably used in more recent years and is something
that is widely used."
SEC. JOHANNS: "Okay. Let me just wrap up with just a
couple of quick comments, and then we'll call it good for
the night and we'll let you get off the line.
"The first thing I want to mention again is that there is
no risk to human health here. The animal did not get in
the food or the feed chain. The firewalls that the USDA
put in place some time ago once again have shown that they
do work. I do not believe that the information that we
have released should impact our discussions with Japan,
Korea or Canada. Again, age of animal alone would indicate
we're dealing with a much different circumstance.
"And with that, I do want to point out that as the doctor
indicated even this 3rd test is not a confirmed case of
BSE. Additional testing will occur. The other 2 animals
did test negative on the additional testing.