U.S. Refused to Do Extra Mad-Cow Test

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http://www.guardian.co.uk/uslatest/story/0,1282,-5100132,00.html

 

U.S. Refused to Do Extra Mad-Cow Test

 

 

Sunday June 26, 2005 7:46 PM

 

AP Photo DCGH106

 

By LIBBY QUAID

 

Associated Press Writer

 

WASHINGTON (AP) - A third and more sophisticated test on the beef cow

suspected of having mad cow disease would have helped resolve

conflicting results from two initial screenings, but the U.S. refused

to perform it in November.

 

That additional test, ordered up by the Agriculture Department's

internal watchdog, ended up detecting mad cow - a finding that was

confirmed on Friday by the world's pre-eminent lab, in England.

 

Only 18 months ago, the department had used the Western blot test to

help uncover the first American case of the brain-wasting illness in cows.

 

The department is pledging that, from now on, it will conduct such

testing on suspicious animals.

 

U.S. officials in November had declared the cow free of the disease

even though one of two tests - an initial screening known as a rapid

test - indicated the presence of the disease. A more sophisticated

follow-up - immunohistochemistry, or IHC - came back negative.

 

``They had two diametrically opposed results which begged to be

resolved,'' said Paul W. Brown, a former scientist at the National

Institutes of Health who spent his career working on mad cow-related

issues.

 

``If you had what they had, you would immediately go to a Western blot

and get a third test method and see which one of the previous two was

more accurate,'' Brown said.

 

Consumer groups and scientists urged the department to perform a

Western blot test and seek confirmation from the lab in Weybridge,

England.

 

In a letter to Consumers Union last March, the department said there

was no need for the British lab to confirm the results and that the

Western blot test would not have given a more accurate reading.

 

``We are confident in the expertise of USDA's laboratory technicians

in conducting BSE testing,'' wrote Jere Dick, an associate deputy

administrator. Mad cow disease is medically known as bovine spongiform

encephalopathy, or BSE.

 

Troubled by the conflicting test results, the department's inspector

general, Phyllis Fong, ordered the Western blot test this month. By

the time an aide notified Agriculture Secretary Mike Johanns, the

testing was under way.

 

The testing was positive. The department then sent tissue samples to

the British lab, which subjected the samples to all the tests again.

 

Johanns, amid an uproar from the cattle industry, was irked that she

did so without his knowledge or consent.

 

``From my standpoint, I believe I was put there to operate the

department and was very disappointed,'' he told reporters Friday morning.

 

By that afternoon, the verdict from Britain was in: The cow had mad

cow disease.

 

In humans, a form of the disease - variant Creutzfeldt-Jakob disease -

has been linked to the consumption of contaminated meat. The rare but

fatal disease has killed about 150 people worldwide, mostly in

Britain, where there was an outbreak in the 1990s.

 

Johanns, who took over the department in January, said the government

will use both the IHC and Western blot tests from now on when initial

screening indicates an animal may have the disease.

 

The world's leading animal health organization recognizes both the IHC

and Western blot tests.

 

The department's testing program, put in place after the first U.S.

case of mad cow disease in 2003, calls for IHC tests when rapid

screening indicates mad cow disease is present. The department uses

rapid tests on about 1,000 cows a day.

 

The department had used Western blot tests since the 1990s to resolve

conflicting results, including on the first case. But since then, the

department has used the Western blot only if samples from an animal

were too degraded to work for the IHC.

 

The current testing program ``might not be the best option today,''

Johanns said. ``Likewise, the protocol we develop as a result of this

testing might not be the best option in 2007,'' Johanns said.

``Science is ever evolving. It is not static.''

 

Critics are saying the department should have gotten it right in the

first place.

 

``They were afraid the truth would come out,'' said Carol Tucker

Foreman of the Consumer Federation of America. Added Michael Hanson of

the Consumers Union: ``This is just foot-dragging, and these delayed

reactions need to really stop.''

 

In the IHC method, a thin slice of the brain - thinner than Saran wrap

- is stained to highlight the mad cow protein and then examined under

a microscope.

 

In a Western blot test, a larger portion of the brain is ground up and

concentrated to pull the mad cow protein closer to one area, then

treated to eliminate normal protein. It is placed in a tray of

gelatin. An electric current is run through the gelatin to separate

the proteins. The proteins are applied to paper and stained for

scientists to examine.

 

The IHC test was negative when the department's lab in Ames, Iowa,

performed it on tissue from the cow last November.

 

The lab also ran the sample through an experimental version of the IHC

test. The tissue looked abnormal but, since the experimental method is

not scientifically verified, the Ames lab did not report the result,

Johanns said.

 

The IHC test was positive when the British lab ran the test last week.

 

Scientists said that because the tests vary from country to country,

it is not unusual for results to vary as well.

 

``There are no two laboratories around the world that are using

identical IHC methods and not a single test that you can take off the

shelf,'' said Danny Matthews, a scientist at the British lab.

 

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