There are probably a few undetected cases of mad cow disease in the United States, but the total — estimated at four to seven — is “extraordinarily low,” Agriculture Secretary Mike Johanns says.
The calculation comes from new testing data released Friday. Testing is likely to be scaled back after a panel of independent scientists reviews the figures, Johanns said.
“The data shows the prevalence of BSE in the United States is extraordinarily low,” Johanns told reporters on a conference call. “In other words, we have an extremely healthy herd of cattle in our country.”
The brain-wasting disorder infected more than 180,000 cows and was blamed for more than 150 human deaths during a European outbreak that peaked in 1993.
The first American animal case appeared a decade later, prompting the United States to increase its testing for mad cow disease, which is medically known as bovine spongiform encephalopathy, or BSE. So far, the U.S. has found three cows infected with the disease.
But the first case, a Canadian cow found in Washington state, is not included in the testing analysis. Including that animal would have revised the estimate of infected cows upward to five to 11 nationwide.
The scientific peer review should be finished by the end of May, Johanns said.
Government proposes fewer tests
Johanns said there is little justification for keeping up the higher testing levels, which rose to about 1,000 samples daily, from about 55 samples daily, after mad cow turned up in the U.S. The current level is around 1 percent of the 35 million cattle slaughtered last year in the U.S.
Johanns pointed out the testing is not supposed to protect food from mad cow disease; testing is supposed to show how prevalent the disease is.
Rules for how cattle are slaughtered keep mad cow disease from entering the food supply for people or animals, he said.
Cattle parts believed most likely to carry the disease are removed from cattle at slaughter. The list of parts that must be removed grows with the animal’s age, because scientists believe infection levels are higher in older animals.
Officials have not decided what the new level of testing will be but said international guidelines call for about 110 tests per day.
A Senate critic of the testing said the data are limited. Some regions of the country had fewer tests because samples were not collected in a scientifically random manner.
“These shortfalls limit the conclusions we can draw from USDA’s expanded testing program,” said Sen. Tom Harkin, D-Iowa.
The department’s inspector general raised similar concerns in a report earlier this year.
Johanns has said he wants to persuade Japan to resume American beef shipments before deciding whether to cut the level of testing. On Friday, he said he will discuss the testing data with his Japanese counterpart, Shoichi Nakagawa, when the two attend trade talks next week in Geneva.
Japan blocked U.S. beef shipments in January after finding veal cuts containing backbone, which Japan has banned from its food supply. The cuts are considered safe to eat in the U.S.
Once the biggest customer of American beef, Japan had only recently ended a ban imposed after the first U.S. case in 2003.