USDA reports: U.S. cow tests positive for Mad Cow Disease

According to the Associated Press:

WASHINGTON - The government says there is no new health risk from mad cow disease despite fresh suspicions about an animal that was previously cleared of the lethal infection.

The Agriculture Department said Friday night it will seek further testing of a tissue sample from a "downer" beef cow — one unable to walk — after receiving conflicting results on tests of it for mad cow disease.... Only one case of mad cow disease has been confirmed in the United States, in a dairy cow in Washington state in December 2003. Since then, preliminary tests indicated the existence of the disease in three cows, but further testing had ruled out any infection.

USDA decided this week to perform additional tests, and one of those three — a beef cow — turned up positive. Johanns said the department's inspector general had recommended the additional testing, but the secretary did not say why.... A sample from the animal was being sent to an internationally recognized laboratory in Weybridge, England, that provided independent confirmation of the first U.S. case of mad cow disease. The Agriculture Department will also conduct further tests....

Commonly called mad cow disease, bovine spongiform encephalopathy, or BSE, is a brain-wasting ailment. In humans, it can cause a variant of the degenerative, fatal brain disorder known as Creutzfeldt-Jakob disease. It has killed more than 150 people, mostly in Britain, where there was an outbreak in the 1990s.

The transcript of the Friday press conference with Agriculture Secretary Johanns contains more detail about the recent postive test for the disease, called the Western Blot, and how it differs from the earlier negative tests.

Here is the activist perspective from John Stauber at the Center for Media and Democracy:

The US government’s elaborate cover-up of mad cow dangers in the United States has begun to unravel. Twenty-four hours after our successful protest (with Organic Consumers Association) of the US Department of Agriculture’s mad cow dog-and-pony show in St. Paul, USDA Secretary Johanns was forced to admit that a cow tested last year and declared safe in fact DID have mad cow disease, or at least has tested positive on the definitive Western Blot test recently administered by USDA and considered the 'gold standard' for BSE testing.

I’ve often charged that the USDA is hiding US cases of mad cow by using the wrong testing procedures and by failing to conduct food safety tests on millions of animals and this announcement proves it. USDA finally used the correct test — the Western Blot test — on this suspect animal and it has proven to be a case of mad cow disease.

Notwithstanding Secretary Johanns' stated hopes in the press conference, I suspect this event will have implications for exports to important overseas markets that have been closed to U.S. beef, especially Japan. In this morning's news, there is talk that Taiwan might close its market to U.S. beef (Reuters).

In other weblog coverage, Thoughts from the Middle of Nowhere questions some of the media coverage of this case, suggesting it may overstate the riskiness of U.S. beef.