account
search
search

Mad Cow: USDA urged to deploy rapid test

By STEVE MITCHELL, Medical Correspondent   |   Dec. 30, 2003 at 3:34 PM
The report on Dec. 23 of a single cow in Washington state infected with mad cow disease has raised concerns about the possibility of additional cattle in U.S. herds harboring the deadly illness.

Although the U.S. Department of Agriculture maintains that its screening program ensures the safety of the nation's meat supply, critics told United Press International the agency tests too few cattle to determine conclusively if the beef supply is safe from mad cow disease.

The critics, including a former rancher and a former USDA veterinarian, said without implementing so-called rapid tests the USDA cannot say with any confidence U.S. beef is free of additional cases of the disease.

The rapid tests, which yield results in a matter of hours and have helped detect mad cow disease in herds in several European countries, would enable the agency to screen millions of animals and provide needed assurances to the American public that its beef supply is safe.

The concern is the mad cow pathogen can infect humans and cause variant Creutzfeldt-Jakob disease, a deadly, brain-wasting condition that struck more than 100 people in the United Kingdom beginning in the late 1990s after they had consumed beef from infected cattle.

So far, the USDA has been reluctant to use the rapid test, claiming its current method -- called the immunohistochemistry test, which can take eight days to produce results -- is adequate to conduct a degree of surveillance officials think is sufficient. Last year, the USDA screened 20,000 cattle out of the more than 30 million slaughtered.

Critics charge the USDA's system, because it tests so few animals, makes it unlikely more mad cow cases will be detected.

Concerns about the possible financial impact on the U.S. beef industry is driving the USDA's reluctance to implement the rapid test, said Howard Lyman, a former rancher turned vegetarian.

"I would bet everything I hold sacred if we went out and tested 5 million mature and downer cattle (in the United States) we would find (more) animals infected with (mad cow disease)," he told UPI.

Both a former USDA veterinarian and a current USDA veterinarian echoed Lyman's comments.

"There'd definitely be (more) positives coming out somewhere along the line if they used the rapid test," Lester Friedlander told UPI. He is a former USDA veterinarian who has been sharply critical of the agency's efforts to ensure the safety of meat.

"The USDA never applied (the rapid test) here because they're afraid of the results," he said.

The current USDA veterinarian, who requested anonymity because of fear of possible repercussions from the agency, told UPI in an interview prior to the discovery of the mad cow case in Washington: "If you do have one (mad cow) in this country, the impact is so great that the government decided not to have it a long time ago."

The USDA denied it is skewing the testing to protect the industry, and had been arguing that American beef is safe and free of mad cow disease.

"We still believe strongly the United States is (mad cow) free," agency spokesman Ed Curlett told UPI in an interview in July -- just six months before the discovery of the first confirmed mad cow in the United States, a cow in Washington state that had been in the country since 2001 and therefore probably was harboring the disease for several years.

At the time, the USDA defended its use of the slow test, calling it the "gold standard" and the most accurate. "We can use the best test out there and still do a high level of surveillance in the U.S.," Curlett said, noting the agency's current level of testing is sufficient to detect mad cow disease even if it was occurring in only one cow per million.

Lyman and Friedlander noted, however, the rapid tests helped uncover cases of mad cow in Germany, Austria and other countries also thought to be free of the disease.

The USDA is "putting the financial success of factory farmers and multinational slaughter facilities far ahead of the concern over consumers," Lyman said. The Canadian beef export business "dried up overnight" after the report of their first case on May 20 in the province of Alberta, he noted.

With countries around the world banning the importation of American meat, the U.S. industry figures to be hit hard. Though the financial impact of the first U.S. case is just beginning to be felt, the nation's beef industry contributes $65 billion per year to the economy.

One reason for USDA's reluctance: Some of the available rapid tests can yield false positives, indicating an animal is infected when it is not. However, at least one rapid test claims to be 100 percent accurate. Manufactured by Prionics, a Swiss company, the test yielded no false results in a 1999 evaluation conducted by the European Commission and it has been used reliably in Swiss cattle for years.

David Westaway, an associate professor of molecular biology at the University of Toronto, who specializes in mad-cow-like diseases, said the rapid tests are based on sound scientific principles and "they're very reliable. They're sensitive enough to pick up cows that have (mad cow) that have not gotten sick yet," he told UPI.

In addition, the rapid tests are "easier to do on large numbers and easier to interpret," Westaway said. They resemble pregnancy tests, turning a different color if they detect mad cow and leaving little room for human error. In contrast, the slow tests used by the USDA can take "years of training to interpret the outcome."

USDA's critics also noted the United States is not even meeting the bare minimum of testing recommended by the United Nations Food and Agriculture Organization, which suggests every "downer" cow should be screened for the disease, as well as healthy animals at random. Downer cattle are those unable to stand, a possible sign of neurological disorders.

The United States had approximately 200,000 downer cattle last year but tested only 20,000 or 10 percent. In previous years, the USDA had tested only a few thousand cattle for the disease and altogether has tested only about 60,000 since it began screening for mad cow in 1990. Some European countries tested hundreds of thousands of cattle before they detected the disease in their herds.

The American Meat Institute, a trade group representing the beef industry, claims testing every U.S. cow is unnecessary and would be prohibitively expensive. The large number of cattle slaughtered in the United States each year compared to the number in European countries -- and the low likelihood of more mad cow cases -- would make testing "a complete waste of time and money," AMI spokesman Dan Murphy said in an interview in July.

"We're confident ... our cattle are free of (mad cow disease), our beef supply is safe and there is absolutely no public health concern as a result of what happened up in Canada," he told UPI.

Murphy acknowledged there might be a need to increase testing, but only to appease the safety concerns of domestic consumers and foreign countries that buy American beef and not due to "a gaping hole in our current surveillance."

USDA officials said Saturday the investigation into the mad cow in Washington indicates the animal originally came from Canada, but there still could be additional cases in U.S. herds because for many years the two countries have exchanged cattle regularly across a largely open border.

More than 1.5-million live Canadian cattle, as well as 83 percent of the 1.2-million metric tons of beef exported by Canada, were imported into the United States last year.

One factor that worries USDA critics is Canada used the same slow test the United States still employs. However, after the mad cow was discovered in Alberta in May, Canadian authorities quickly shifted to the rapid test to screen more than 2,000 cattle as they attempted to determine if there were additional infections.

USDA officials said Sunday the ramifications of the first U.S. case of mad cow might force changes in their surveillance system for the disease, including increasing the number of animals screened for the disease.

Asked in July if the USDA was considering using the rapid test, agency spokesman Curlett said: "Right now we're still sticking with the gold standard, the immunohistochemistry test. I'm not aware of any plans for that to change in the immediate future. However, all options are on the table."

A USDA veterinarian offered a different perspective to UPI in July. The veterinarian, who requested anonymity, acknowledged hearing indications the agency may put the rapid test in place. "I think that's being considered," the veterinarian said. "We're hearing a great deal about it."

Now, the USDA may have no choice and may be forced to implement the rapid test to appease countries concerned about the safety of American beef. Japan, the largest importer of U.S. beef, already has indicated it will require increased levels of testing in the United States before it reopens its borders.

--

Steve Mitchell is UPI's Medical Correspondent. E-mail sciencemail@upi.com

Topics: Dan Murphy
© 2003 United Press International, Inc. All Rights Reserved. Any reproduction, republication, redistribution and/or modification of any UPI content is expressly prohibited without UPI's prior written consent.
x
Feedback