How safe is U.S. beef to eat?
One mad cow in Canada spurs many questions in U.S.
Saturday, June 7, 2003 Posted: 7:39 AM EDT (1139 GMT)
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(AP) -- As barbecue season approaches, food safety critics are demanding more stringent controls on the beef ranches and processing plants that provide those sizzling burgers and hot dogs.
But until that happens, some diners wonder: Is it safe to eat beef?
The concern has arisen from a single case of mad cow disease in Alberta, Canada, disclosed two weeks ago. This past week, agriculture investigators learned that some of the cattle from the sick cow's herd wound up in Montana.
Bovine spongiform encephalopathy has not been found in any U.S. or Canadian beef products. But Canada sends 1.7 million cattle south every year. Until an import ban on May 20 when BSE was discovered, processors regularly mixed beef from both nations.
Prions, the mysterious, abnormal proteins believed to trigger BSE, have not been found in beef muscle. So even most critics aren't condemning sirloins or hamburger ground from specific cuts like chuck or round.
But processed foods like beef sausage, hot dogs, luncheon meats, taco fillings and some pizza toppings are a dicier subject. Such products contain meat scoured from cow carcasses by automated equipment that pressure-strips flesh from awkward places like backbones.
Prions collect in the cow's brain, spinal cord and other nervous system tissue. Processors are supposed to remove the spinal cord to minimize health risks. However, a December 2002 inspection showed that one of three samples from 34 beef processors contained central nervous system tissue.
In March, the U.S. Agriculture Department began more careful testing of meat processors that use the automated equipment.
'They think they are buying meat'
The fatal human version of mad cow known as variant Creutzfeldt-Jakob Disease has killed at least 132 people since 1986 -- 122 of them in Britain, where processed meat products contained larger amounts of such tissue.
In the United States, "We're talking about stray bits of cells being detected through testing methods," said Jim Hodges, president of the American Meat Institute Foundation.
But a single cell might contain many prions.
"Consumers don't want to purchase products with central nervous system tissue in it," said Caroline Smith DeWaal, food safety director for the Center for Science in the Public Interest. "They think they are buying meat."
As the Canada inquiry continues, experts still are ruminating over food safety and basic bovine biology. There is no obvious explanation for the Canadian case.
A cow 6 to 8 years old showed severe symptoms when it was slaughtered. It was sent to a mill for chicken feed or dog food, and testing of the brain later revealed that it had BSE.
Researchers say that probably didn't develop spontaneously. More likely, they say, the animal was infected through prion-contaminated feed years ago.
"It's critical that we find the source," said Iowa State University veterinarian Nolan Hartwig. "If there is a leak in the system, we need to know about it."
Industry officials say this random surveillance system used by the United States and Canada proved itself effective by spotting the cow. But consumer advocates say this case is a sentinel, not an aberration.
"The fact that BSE hasn't been found here doesn't mean it isn't here," said CSPI's DeWaal. "It's very likely we'll see a case or more of mad cow disease here."
Critics say the U.S. system allows big loopholes.
Europe tests one in four cattle for BSE, or about 10 million animals annually. All slaughtered cattle over 30 months old are tested, an age when BSE is apparent in lab samples and could spread. Britain bans consumption of cattle older than 30 months.
Japan tests all 1.3 million beef carcasses it processes yearly.
In contrast, the United States slaughtered 35.7 million cattle last year and tested 19,990 for BSE -- about one in 1,800. Inspectors focus on animals showing symptoms of illness. (Canada follows a similar plan.)
Potential regulatory loopholes
Critics recommend a precautionary program more like the one in Europe, which uses a rapid test and then a second more extensive test on positive cases. The testing costs $80.
Michael K. Hansen of Consumers Union said the current U.S. testing sample is "far too small to detect a problem that might be growing."
Industry officials say consumer groups are "imagining a BSE epidemic."
Most cattle slaughtered in the United States are younger than 30 months old, so testing them would be a "huge waste of money and resources," Hodges said.
Livestock feed is a second potential crack in the regulatory firewall. Britain's mad cow outbreak spread quickly because infected cows and sheep were processed into feed given to healthy cattle.
The United States and Canada banned such feed for cattle in 1997. Because of its age, however, the infected Canadian cow could have eaten tainted food before the ban.
Future BSE pathways could be less direct, too.
It took nearly four months to test the Alberta cow. During that period, the cow was rendered and made into chicken feed and dog food. Dogs and poultry cannot contract BSE, but inspectors cannot prove that prion-laden feed did not inadvertently contaminate feed meant for cattle.
And poultry may act as a reservoir for BSE. If chickens picked up prions in their feed and were themselves processed into cattle feed, it may perpetuate a prion infection cycle in future herds, critics speculate.
Also questionable are blood and other protein materials used in dozens of supplements, including weaning products for calves, Hansen said.
A third potential loophole is cattle identification. The infected cow in Alberta belonged to at least four herds. Investigators trying to locate those other cattle have been slowed by incomplete records. Nine herds have been quarantined so far and more than 1,700 animals destroyed.
Five bulls from the herd were shipped to Montana six years ago. Later, they were slaughtered in the United States, but details are sketchy. Montana officials do not believe the animals were infected, nor used in animal feed.
"It's time the U.S. livestock industry seriously look at tracing animals from conception to consumption," Hartwig said. "You could build a huge bureaucracy in a hurry. But look at the Canadians now."
SIDEBAR
HUMAN THREAT
Mad cow disease was first reported in the United Kingdom in 1986, peaking in 1993 with almost 1,000 new cases per week.
In 1996, variant Creutzfeldt-Jakob Disease (vCJD) was detected in humans and linked to the mad cow epidemic. Eating contaminated meat and cattle products is presumed to be the cause.
Both are fatal brain diseases with unusually long incubation periods, often lasting years.
To date, no case of mad cow disease has been identified in the United States.
As of April 2, 2002, a total of 125 cases of vCJD had been reported in the world: 117 from the United Kingdom, six from France, and one each from Ireland and Italy.
Source: CDC
"How safe is U.S. beef to eat?"
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