January 4, 2004 The Wall Street Journal by Thomas M. Burton and Martin Fackler

Is the U.S. next?

It wouldn't be hard: Four companies already offer test kits that can, within four hours, tell if a slaughtered cow carries bovine spongiform encephalopathy, otherwise known as BSE or mad cow disease. It wouldn't cost much: Test kits cost about $10 apiece. Add in salaries of lab technicians, the cost of grinding up and delivering cattle brain samples for testing, and the tab would be $30 to $50 for each animal, industry experts say. The average U.S. cow slaughtered for food yields meat with a retail value of $1,636.

Each year in the U.S., about 35 million cattle are slaughtered. About 10 million of these animals - those over 30 months of age - would be tested for BSE if the U.S. were to adopt European standards, because age is associated with infection. The grand total to test about 10 million cows in the U.S. would be $300 to $500 million a year. Considering that Americans spend more than $50 billion on beef annually, that would add between six cents and 10 cents a pound.

"Cost should not be a prohibitive factor," says Scott McKinlay, president of InPro Biotechnology Inc., South San Francisco, California, a test-kit maker founded by Nobel Prize-winning researcher Stanley B. Prusiner.

"Look at Canada as an example," says McKinlay. "They have suffered about a $600 million loss already" in lost beef exports and consumption.

Japan has the most extensive testing system in the world. All slaughtered cattle there are tested, no matter the age. "Public opinion supports the policy of testing every cow," says Kazuki Ikeda, an official in the Agriculture Ministry's Department of Meat and Poultry. "For a relatively small cost, consumers feel their safety is guaranteed."

Most European Union countries test all slaughtered cattle older than 30 months; Germany includes all older than 24 months. But Japanese officials point out their tougher testing has found the disease in cows as young as 21 months, which would have slipped past European screening. Japan, the largest importer of U.S. beef with $900 million in purchases in 2002, asked the U.S. earlier this week to start testing all cows.

The American approach has been to test only about 20,000 cattle annually, roughly one in every 1,700 slaughtered. The animals chosen for testing are "downer" cattle, those too ill or lame to walk into the slaughterhouse, and are subjected to an "immuno-histochemistry" test that takes at least five days for results. The Washington state Holstein that was tested and found to harbor mad cow disease was a downer, and its meat entered the food chain before the testing was complete - an occurrence that might have happened any time under regulations then in effect.

U.S. industry and government executives say they see no great need for wider testing. But others point out that symptomless cattle can carry the disease. Indeed, among 8.5 million older cattle tested in Europe in 2001, tests found 2,142 carried BSE.

Because of its slowness, the U.S.'s current immuno-histochemistry test wouldn't be practical for widespread use. Various firms have created faster tests. But before any could be used in the U.S., the tests must first be approved by the Agriculture Department. That hasn't happened yet.

Any testing program would need government vigilance to ensure that labs employ trained personnel and that tests minimize the problem of false positives.

Industry and U.S. laboratory estimates suggest the false-positive rate is about 1 in 10,000 with some of the tests. This would mean 1,000 cattle out of 10 million tested could result in false positives. When that happens, the next step is to "test the test" with the slower test used by the Agriculture Department.

A potentially more serious problem: false negatives. Prions can be present elsewhere in younger animals before traveling to their brains.

There is currently no practical way of rooting out all such cases, but these are believed to be extremely rare and far less likely to infect people who eat the affected meat.