050810 Mad Cow Case Demonstrates Weaknesses in Testing

August 6, 2005

Fort Worth, TX (Knight Ridder Newspapers) - Although meat from a 12-year-old Texas beef cow with mad cow disease never entered the food supply, critics of the Agriculture Department said the twisted, seven-month-long tale of this animal highlighted bureaucratic missteps and weaknesses in the food safety system.

Public confidence wasn't enhanced last week 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. 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 Texas cow, which 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 Washington-based advocacy group, Center for Science in the Public Interest. "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 (IHC) test, proved negative for BSE.

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.

Unbeknownst to Fong and the public, Ames researchers had also used an experimental rapid version of the IHC test on brain tissue from the Texas cow. That proved positive for BSE, but staff members thought the result was technically flawed and the USDA didn't 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 points to possible BSE. 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, noted Michael Hansen, a senior researcher with the organization.

In hindsight, the March 18 response to Consumers Union by Jere Dick, associate deputy administrator of USDA's animal health policy and programs, smeared egg clearly across the department's collective face.

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.

Sen. Tom Harkin, D-Iowa, noted the obvious in a July 7 letter to Johanns:

"Without the prompting of the (inspector general's office), we still would not know that the brain sample in question tests BSE-positive."

While Americans should have no misgivings about eating steaks and hamburgers, Harkin said, "there is a limit to how much of its own errors, inconsistencies and lack of transparency USDA can reasonably expect consumers to abide and still have confidence in the safety of beef."

All the criticism might obscure the fact that meat from diseased livestock has been kept out of the food supply. BSE 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.

USDA's animal health officials were dealing with a highly unusual situation, said Keith Belk, a Colorado State University animal science professor who closely follows the BSE issue.

"There clearly were some mistakes made, but this was a pretty unique cow," Belk said. "She had the disease, and it incubated for a long time. But it apparently received a light dose of prions that were very sporadically spread" in the brain tissue.

The tissue sample, a pie-slice-shaped sliver taken from the obex, a slight bulge in the brain stem, had so few BSE prions at some points that a British expert, Dr. Danny Matthews of Weybridge, said tests easily could have missed them.

Matthews has said BSE is becoming rarer and more difficult to detect because of effective bans on tainted cattle feeds, which are believed to spread the disease.

Some of the missteps, ironically, were caused by USDA staff doing exactly what they were supposed to do - faithfully following measures that go far beyond international standards, Belk said in a call from Fort Collins, Colo.

"They appeared to have made some significant errors, which unfortunately made them appear foolish," Belk said. "Most scientists around the world would have argued that they should have run both the Western blot and IHC tests. I think they would have liked to have done so; but because of policy in place, their hands were tied."

Under lab rules in effect in November, the USDA staff in Ames was not permitted to carry out any other type of test after it received a negative result from the second round of testing, using the IHC method.

Communication miscues haven't helped the USDA's image in its handling of the Texas case.

In June, the USDA finally confirmed that the yellow to cream-colored cow had arrived dead at a meatpacking plant, not a dog food plant as originally reported.

And it had not been a downer - a live but nonwalking animal - as described by officials for nearly seven months. Making matters worse, the initial description of the cow as an Angus was wrong, and some of its high-risk body parts were tossed in a bin with those of other cattle, creating the need to run a number of DNA tests.

Dewaal also criticized the successful effort to keep the name and location of the ranch that produced the Brahman cross-bred cow secret. The ranch has been speculated to be somewhere in Southeast Texas.

"Who are they protecting?" she asked. "The only person it protects is the rancher."

But officials like Carla Everett, a spokeswoman with the Texas Animal Health Commission, say that maintaining confidentiality is necessary to prevent such operations from being needlessly stigmatized and to ensure future cooperation from ranches to which other diseased animals might be traced.

Although chastened, the USDA said it had no choice but to treat the Texas cow case as it had.

"It was handled within our protocol with few exceptions," said Jim Rogers, a spokesman for the department's Animal and Plant Health Inspection Service.

But the department is owning up to some mistakes.

Johanns has acknowledged that some things should have been done differently, Rogers said. Among them: Animal parts from different cattle should not have been commingled as they were at the Waco pet food plant; the Ames laboratory should not have run an experimental test while running the official test; and the lab made a verbal disclosure, but it should have presented a written report.

Whatever steps the USDA takes, it could find itself in a no-win situation, Rogers said.

In November, Western blot was not part of the testing protocol because it was not deemed appropriate in that situation.

"Let's go back in time and say we had conducted Western blot," Rogers said. "We would have critics saying we had stepped outside our protocol."

In fact, the National Cattlemen's Beef Association publicly criticized the inspector general for stepping out of the testing routine - just before it became clear that her irregular action had turned up the positive BSE finding.

Reinforcing experts' description of the Texas cow as an unusual case, Rogers noted that after Fong requested that Western blot be used on the brain sample, "they tested it 10 times - five of which were negative and five positive."

The results could be far different depending on what part of the sample was examined because of the erratic spread of BSE prions. Scientists believe that these submicroscopic flecks of protein spread BSE, a rare but always fatal disease discovered in 1986, through feed contaminated with rendered cattle parts.

The infected Texas cow was born before such tainted feed was banned in the United States in 1997. Ninety-seven percent of beef now consumed by Americans comes from cattle born after the ban, according to the National Cattlemen's Beef Association.

By comparison, Japan did not ban such feed until 2001, possibly contributing to the 20 BSE cases there - and a heightened popular distrust of its food security program, Belk said. That lack of public confidence prompted testing of every animal going to slaughter and a continued reluctance to end a 19-month ban on U.S. beef imports.

While such feed is banned for cattle, it can still be fed to pigs and chickens, which cannot contract BSE.

But some scientists and consumer groups, fearing mislabeling of sacks or other human errors, have urged the Food and Drug Administration, which regulates the feed industry, to act on its own January 2004 recommendation and ban it for poultry and pigs, too.

Of the 153 worldwide cases of a fatal human ailment believed caused by BSE-contaminated beef products, the only victim of variant Creutzfeldt-Jakob disease in the United States was a Florida woman who had lived in Britain when such tainted food was available.

Six months after the first U.S. case in a Canadian-born dairy cow was discovered in December 2003, scientists said BSE was probably present at low levels in the U.S. herd, and the USDA launched a widespread surveillance effort. The beef industry notes that the Texas animal was the only cow found with BSE after 419,113 high-risk animals have been tested.

In the most recent case, involving a cow that was euthanized after severe calving problems whose test samples were forgotten about, the carcass was incinerated. The Texas and Washington state cows were discovered before they entered the food chain, reinforcing the government and industry's insistence that world-class firewalls have kept U.S. consumers protected.

After the Texas cow arrived dead at a Waco packinghouse, it was trucked across town to a dog food plant, where test samples were taken. The animal's body, kept segregated, was incinerated at Texas A&M University.

Unfortunately, by then its parts were commingled with three other cattle, making the difficult task of tracing a suspect cow without a mandatory national animal identification program even harder. This was seen as another blunder by authorities.

Hansen of Consumers Union complained that little is known publicly about the 419,113 tested cattle - or many others with central nervous system problems that were never examined.

He cited an August 2004 audit by the inspector general's office as saying that only a fraction of the highest-risk cattle - erratic-acting animals that tested negative for rabies - were not given the rapid BioRad test for BSE.

In fiscal 2003, for example, 108 Texas cattle were tested and found clean for rabies, but only 29 of this high-risk group were checked for BSE. In South Dakota, 81 tested cattle were negative for rabies, but none were given BSE tests.

Rogers conceded that there was a "mix-up" in states where testing guidelines were not clearly understood. The confusion has been remedied, and by late September, all animal inspectors understood that such high-risk cattle must be tested for BSE, he said.

Chief among complaints by watchdog groups like Consumers Union and the Center for Science in the Public Interest is that the United States - unlike the European Union, Japan, Canada, Australia and New Zealand - still has no mandatory national identification program for tracking cattle. An ID program would help quickly trace the origins of a contaminated cow.

As the mad-cow story developed this summer, the National Cattlemen's Beef Association got a head start on Johanns by saying it was starting its own animal ID system and hoped to have it operational in January 2007.

The association is seeking to have a system that would eventually be taken over as the national program. It envisions one that would ensure confidentiality of certain proprietary data that cattle operations and others want withheld for competitive reasons.

"For example, Cargill doesn't want Tyson to know where they purchase cattle," said Belk of Colorado State, referring to major beef processing companies.

And ranchers, some of whom have run cattle for generations, are worried about consumer lawsuits, he said.

"If you can determine where something comes from, it opens the door to liability," Belk said.

Johanns had announced that the government's mandatory ID system won't be up and running until 2009.

"I think the system is flawed as long as we don't have a national mandatory system for tracking cows," said Dewaal, who noted that Canada went from a voluntary to a mandatory system in one year. "We may be better at finding the one infected animal but not others similarly exposed to the disease.

"And we are surprised by the extraordinary delay."

Consumers, ever more concerned about food safety, are putting money where their mouths are and demanding beef traceability.

In Texas, chains such as United Market Street, Whole Foods and Central Market are offering source- verified beef - meat whose herd or ranch origin is spelled out to consumers.

In doing so, the market will push for an animal ID system to be implemented before 2009, Belk predicted. And source verifiability might be needed to re-establish lost export markets, he said.

And such traceability carries plenty of benefits.

Some systems could go beyond a mandatory animal ID system, Belk said, providing useful information: Is the animal free of antibiotics? Was it given vitamin E for a certain antioxidant level?

The producer could also receive feedback on whether livestock management techniques led to more tender cuts, for example.

"It's not all related to safety," Belk said.


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