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From: TSS ()
Subject: Faults in USDA testing cited Mad cow case in Texas showed glaring missteps
Date: August 7, 2005 at 12:27 pm PST

Faults in USDA testing cited
Mad cow case in Texas showed glaring missteps
By Barry Shlachter, Knight Ridder | August 7, 2005

FORT WORTH -- Although meat from a 12-year-old Texas beef cow with mad cow disease never entered the food supply, critics of the US Department of Agriculture said the twisted, seven-month-long tale of this animal highlighted bureaucratic missteps and weaknesses in the food safety system.

Public confidence was not enhanced last month when the USDA announced that a private veterinarian had ''forgotten" about a brain tissue sample he took in April. It came from another cow that was suspected of having had the brain-wasting disease bovine spongiform encephalopathy, or BSE. On Wednesday, the USDA said that cow tested negative for the disease.
Watchdog groups awarded barely passing marks to the department for its handling of the case; the cow turned up dead at a Waco packing plant Nov. 15. The USDA finally confirmed the mad cow case June 10 after multiple tests.

''USDA gets a D or D minus," said Caroline Smith Dewaal of the Center for Science in the Public Interest, an advocacy group based in Washington. ''The best thing that came out of this is the work of the inspector general."

It was the department's in-house watchdog, Inspector General Phyllis Fong, who skirted the USDA hierarchy by ordering retesting with a different method more than six months after a routine second-round test, known as the immunohistochemistry, or IHC, test proved negative for the disease.

Agriculture Secretary Mike Johanns, who assumed office in January, has said he neither knew about nor authorized the retesting by the National Veterinary Services Laboratories in Ames, Iowa.

Just why Fong, a lawyer who grew up in Hawaii, acted in such a forthright, hierarchy-dodging manner has puzzled many involved in the industry.

In a statement, her office said the retesting was prompted by a review of ''voluminous records" showing an unusual pattern of conflicting test results in the case. Industry sources say there is speculation that she responded to concern expressed in scientific circles.

Two early tests, one reportedly conducted at Texas A&M University and a second in Ames, produced conflicting results -- one inconclusive, one negative.

What Fong and the public were unaware of was that Ames researchers had also used an experimental rapid version of the IHC test on brain tissue from the Texas cow. That proved positive for the disease, but staff members thought the result was technically flawed. The USDA did not disclose until just recently that the Ames lab had conducted the experimental test.

Months later, Fong stepped in and ordered more tests. A ''Western blot" test proved positive, as did later tests at a lab in Weybridge, England.

Finally in June, two days after the Weybridge lab confirmed the mad cow case, a chastened USDA announced that in addition to the routine IHC test, it was adopting the Western blot procedure whenever an initial ''BioRad" screening test indicates mad cow disease is possible. In addition, backup tests will now be conducted at Britain's national veterinary laboratory in Weybridge when earlier test results conflict or are inconclusive.

All this sounded familiar to Consumers Union.

In February, the nonprofit public interest group that publishes Consumer Reports urged the USDA to take those same steps in regard to the Texas cow, said Michael Hansen, a senior researcher with the organization.

Referring to the Texas cow, Dick wrote: ''We are confident in the expertise of USDA's laboratory technicians conducting BSE testing and do not feel that such confirmatory testing by the Weybridge laboratory is generally necessary, nor would the use of the Western blot test have enhanced the result of our November 2004 testing."

The opposite turned out to be true.

All the criticism might obscure the fact that meat from diseased livestock has been kept out of the food supply. Mad cow disease is carried by hard-to-destroy protein prions, which scientists believe can cause a rare human disease -- variant Creutzfeldt-Jakob -- if found in beef.

The food supply has been protected by a ban for human consumption of tissue most prone to prion contamination, including beef brain, scrapings from the spinal column, and a small section of the intestine.

Chief among the concerns of watchdog groups is that the United States -- unlike the European Union, Japan, Canada, Australia, and New Zealand -- has no mandatory national identification program for tracking cattle. An ID program could help trace the origins of a contaminated cow.

As the mad cow story developed this summer, the National Cattlemen's Beef Association said it was starting its own animal ID system.

© Copyright 2005 Globe Newspaper Company.



Posted on Thu, Aug. 04, 2005

Tests show no BSE in cow

By Barry Shlachter

Star-Telegram Staff Writer

Concerns over another possible case of mad cow disease were laid to rest Wednesday when new rounds of tests at a federal veterinary laboratory in Iowa and Britain's counterpart facility in Weybridge, England, proved negative.

"Needless to say, we are very pleased with these results," said John Clifford, the Agriculture Department's chief veterinarian.

It was a quirky case in the prolonged and costly fight to stamp out the highly unusual brain-wasting disease, bovine spongiform encephalopathy, or BSE.

While enduring criticism for the handling of a Texas cow that was found to be positive for BSE seven months after it tested negative, the department disclosed last week that a private veterinarian had forgotten about a brain tissue sample taken in April from a cow with suspicious calving problems. The USDA did not disclose the cow's location.

Cows with calving paralysis are typically considered downers -- alive, but unable to walk -- that require BSE testing under federal guidelines.

The chemicals used by the unidentified veterinarian to preserve the sample made it impossible for animal protection investigators to run an initial screening test, known as rapid BioRad.

Instead, an immunohistochemistry test was done, and the result carried telltale staining that shows up when BSE is present, but in an abnormal pattern, Clifford said earlier.

On Wednesday, he explained that the initial nondefinitive result was caused by "artificial or untrue" staining. "And while this staining did not resemble BSE, we felt the prudent course was to conduct the additional tests."

"Through all the twists and turns of this saga, we continue to come to the conclusion that the U.S. beef supply is safe and the nation's herd is free of BSE," said Matt Brockman, executive vice president of the Fort Worth-based Texas and Southwestern Cattle Raisers Association.

The first case, involving a Canadian-bred dairy cow, was discovered in Washington state in December 2003. The second was a native-born Texas beef cow whose BSE contamination was confirmed June 24.

At no time was the U.S. food supply at risk, because both carcasses were incinerated. Both animals were born before the 1997 ban on cattle feed made from rendered cattle parts, a product scientists believe spread the disease. Most beef now consumed comes from cattle born after 1997.

A rare human disease, variant Creutzfeldt-Jakob, is believed to be contracted from BSE-tainted beef. The only U.S. case involved a Florida woman who lived in Britain when BSE-contaminated beef were sold.

Barry Shlachter, (817) 390-7718

Results Negative in 3rd Possible Case of Mad Cow
Published: August 4, 2005
A third cow suspected of having mad cow disease does not on closer examination appear to be infected, the Department of Agriculture said yesterday.

After tests conducted last week yielded ambiguous results about whether the 12-year-old cow was infected with the brain-wasting disease, tissue samples from the animal were retested by the department's laboratory in Ames, Iowa, and by experts at the Central Reference Laboratory for mad cow disease in Weybridge, England.

Both tests came back negative for the disease, bovine spongiform encephalopathy or B.S.E., said Dr. John Clifford, the department's chief veterinarian.

"Needless to say, we are very pleased with these results," Dr. Clifford said in a statement. "Our enhanced surveillance program is designed to provide information about the level of prevalence of B.S.E. in the United States, which by any measure is extremely low."

Two cases of mad cow disease have been confirmed in the United States. The first, involving a cow born in Canada, was discovered in Washington State in December 2003. The second occurred in a cow born in Texas that died in November. The cow's brain was not tested for the disease until June, when tests in England confirmed the diagnosis. Tests conducted earlier in the United States had been negative.

Several types of tests are used to detect the presence of the misfolded proteins, prions, that scientists believe cause mad cow disease. One such test, an immunohistochemistry test, or IHC, was the source of the ambiguous results for the third cow.

In the test, scientists examine extremely thin slices of tissue taken from the brainstem or from other parts of the nervous system where the prions are thought to accumulate.

The slices are treated with antibodies that bind to abnormal proteins. The antibodies are labeled with dyes so they can be seen with the naked eye, and the dyes then show up in a typical staining pattern if the prions are present.

The ambiguous test last week produced some staining but it did not resemble mad cow disease, said Jim Rogers, a spokesman for the Agriculture Department. He said the staining could have been caused by a contaminant in the test or in the tissues, but said, "The fact there was staining made us want to redo the tests."

The IHC test can pick up infectious prions only if the particular slices of tissue taken from the cow's brain happen to contain them, said Dr. Jiri Safar, a neurologist at the University of California, San Francisco, and an expert on prions. This can be a hit-or-miss process, he said, and even if prions are present, certain antibodies can fail to bind if the level of infection is extremely low.

Moreover, cases of so-called atypical bovine spongiform encephalopathy have been showing up in a small number of European and Japanese cows, Dr. Safar said. The antibodies used in conventional IHC tests can fail to identify those abnormal proteins that tend to accumulate in tissues that are not usually examined under the test's protocols.

The suspect cow died on the farm where it was raised after complications from giving birth. The farm's location has not been released. The cow, which was destroyed, died in April, but the veterinarian who took its brain tissue forgot to send the sample for testing until last month.

-------- Original Message --------
Subject: hey there mike, some history on TERRY'S mad cow from TEXAS that was inconclusive ;-)
Date: Wed, 02 Feb 2005 16:24:22 -0600
From: "Terry S. Singeltary Sr."


for your files for a later date;-)


follow the thread. moser of prionics is in it and Everet of TAHC.

SO close, BUT yet so damn far away...TSS

-------- Original Message --------
Date: Wed, 24 Mar 2004 16:12:06 -0600
From: "Terry S. Singeltary Sr."
Reply-To: Bovine Spongiform Encephalopathy

######## Bovine Spongiform Encephalopathy #########




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