How Now, Mad Cow?
Just before Christmas, U.S. consumers and the country's $38 billion beef industry got a glimpse of the damage caused by mad cow disease, the brain-destroying ailment that has afflicted cattle around the world over the past decade -- and has killed a handful of humans, too. Since the case of bovine spongiform encephalopathy (BSE) was discovered in Washington State on Dec. 23, dozens of countries have banned the import of U.S. beef, resulting in depressed cattle prices and the loss of hundreds of beef processing jobs -- even though not one person in the U.S. has yet been diagnosed with the human form of the disease, which can take 10 years or more to appear.
The incident has caused everyone from the U.S. Agriculture Dept. (USDA) to cattle ranchers and consumer advocates to confront the question of what it will take to restore and preserve trust in American-grown beef -- and to win back some $3 billion in meat exports.
In theory, the answer is more thorough testing of flesh from the nervous systems of slaughtered animals. Problem is, few agree on the best way to achieve this. Ranchers, beef processors, and their allies in the USDA argue that current tests are too cumbersome, expensive, and time consuming to test samples of more than a few thousand animals a year.
Experts on the other side note that Japan tests every slaughtered animal before it's consumed -- and that European countries do cheaper, faster testing on a much higher percentage of beef than the U.S. does.
Neither side seems likely to change its opinion. But it's clear that if cheap, fast, and thorough tests could be devised, America could revive its beef exports. On Jan. 9, in fact, the USDA began accepting applications from makers of rapid diagnostic tests, an indication that the agency expects to require wider testing of cattle carcasses.
Here are some questions and answers about the key issues surrounding the testing debate:
What kind of testing for BSE goes on now?
Only about 20,000 animals of the 35 million that were slaughtered in the U.S. in 2003 were tested for BSE by the USDA. Brain tissue from "downer" animals -- those literally unable to walk into the slaughterhouse -- is shipped to the USDA's testing center in Ames, Iowa, where researchers take several days to analyze the sample. The test is known as the "gold standard," since it determines whether brain cells contain prions, the abnormal protein particles that cause BSE.
In Europe, which has been dealing with BSE in its herds for more than a decade, testing varies by country. But generally, governments test animals that are older than 30 months, since animals younger than two years are believed to be at low risk for contracting the disease, which in cattle has an incubation period of up to eight years.
In Japan, the government has been testing all animals slaughtered since the fall of 2001. Japan tested 1.2 million animals in 2003. The country has turned up nine positive results since it started broad testing -- at a cost of about $65 million.
The amount of testing in the U.S. seems very low compared with other countries. Why the big difference?
Some would argue that more extensive BSE outbreaks in those countries warranted much more aggressive testing. Japan had enough cases of ill animals that the public began to lose confidence in government reassurances about the safety of the beef supply. So now, no animal is left behind, and public trust has returned.
The U.S. has so far found only one infected cow, after all. In part, that's because the USDA's ban on feed containing rendered beef, which causes the BSE infection, has been in place since 1997. U.S. beef comes mainly from animals younger than 30 months, whereas much of Japan's beef is from older animals. (In November, however, a 21-month-old Japanese bull tested positive for BSE.)
The U.S. has also been aggressive in blocking imports from countries with even a single case of mad cow. And since the diseased cow appeared in Washington, the USDA has banned the process of mechanically separating the last morsels of meat from a bovine skeleton, a measure that should lessen the risk of mixing potentially hazardous nervous-system tissue with meat bound for supermarkets.
So is the U.S. doing enough?
The answer depends on whom you ask. The beef industry and the USDA take the view that surveillance is sufficient, given the measures now in place to prevent BSE and find cases quickly. Many experts believe that it isn't necessary to test every animal or even all animals over 30-months old. "Testing everything is a big jump," says Deborah Roeber, assistant professor of pre-harvest food safety and meat quality at University of Minnesota.
Nonetheless, an inescapable fact is that the beef-export market is dead for now. And though U.S. demand has held up, cattle prices are in trouble. In the weeks since Christmas, cattle futures have fallen about 15%, as U.S. producers have been left with about 40 million pounds per week that would have gone to other countries.
If such a surplus persists for long, the impact could be significant. To start selling overseas again, "the U.S. will have to test large numbers of animals," declares Michael Hansen, senior research associate at Consumers Union, a nonprofit consumer interest group. "Otherwise, Japan will not open its markets." How much would it cost to test every single cow?
The "gold standard" analysis that the USDA has been doing costs about $100 per test, so it's clearly not economically feasible to use it on every cow. Rapid tests, which grind up brain tissue and detect the presence of prions using antibodies -- basically, the tests used in Europe and Japan -- cost less. Consumers Union figures that these tests would add only pennies to the price per pound of beef. A $25 test would increase the price by about three cents per pound.
That seems reasonable.
Yes, but it reflects only the cost of the test. Many experts argue that added logistics and infrastructure costs would bring the real expense of testing closer to $30 or $50 per animal. Consider that Japan had to buy $100,000 worth of equipment for each of its 117 government labs to do test every animal for BSE. The American Meat Institute estimates that in the U.S., the infrastructure cost to test every animal slaughtered would be around $1.8 billion.
Dr. Alfonso Torres, associate dean for veterinary public policy at Cornell College in Ithaca, N.Y., predicts that more testing is unavoidable in the U.S. He argues for the creation of a system for doing rapid tests, even if they're still done on a small scale, so that beef-processing plants can quickly get the results and move on to making rump roast or hamburger.
So far, the USDA has approved only the days-long "gold standard" test -- though that will likely change soon. With a system for rapid testing in place, adds Roeber, "[beef processors] would always have flow of product" -- something they might not have were the lengthier test required for all animals.
Are prices for tests coming down?
Yes. Abbott Labs (ABT ), which is marketing a test made by the Irish company Enfer, has sold 2 million BSE tests since 2001. Jim Koziarz, vice-president for research and development at Abbott Diagnostics, says these tests can cost as little as $10 to $13 per animal.
Brad Crutchfield, vice-president for life sciences at Bio-Rad (BIO ), says its rapid test costs about $10 per animal, down from $18 a few years ago. And with so much competition -- Prionics, InPro, and Idexx also make rapid tests -- prices are likely to keep falling.
Can faster tests be devised?
Bio-Rad's Crutchfield says his company's test takes about 3.5 hours. A lab can process 1,000 tests in eight hours, vs. the 2,800 or so animals a state-of-the-art beef plant can process over the same period. A next-generation, more automated Bio-Rad test that's now being run through its paces should enable a lab to process 1,800 to 2,000 tests in eight hours. Crutchfield thinks it should be feasible to shorten the test to one or two hours over the next few years.
Stanley Prusiner, winner of a Nobel prize for his research on prions, developed the test that InPro is beginning to market in Europe. Dr. Giuseppe Legname, a senior researcher working in Prusiner's lab at the University of California, San Francisco, says the test is more sensitive for BSE than others, reducing the chance for false-positives. And a lab could handle 8,000 samples per day, he says.
What else besides testing can be done to detect mad cow?
Good question. While every cow is now tracked by its owner, the U.S. has no unified system for tracking animals from birth to death. However, beef-industry groups are discussing a proposed national I.D. plan for cattle. "We definitely need this," says Cornell's Torres, who adds that such a system probably should be made "mandatory."
Stephen Arens, senior director at the Uniform Code Council, a nonprofit standards group, says government agencies have begun to consider using new radio frequency identification (RFID) chips for livestock tracking. "Theoretically, we would be able to track a product or ingredient from the farm to the fork," Arens says.
That, and much broader testing, could go a long way to restoring trust in the safety of U.S. beef.
By Amy Tsao in New York