Agriculture Secretary Mike Johanns announced last week USDA’s estimate for the prevalence of bovine spongiform encephalopathy (BSE) in the United States.

              "Our enhanced BSE surveillance program has been an enormous undertaking, but well worth the effort," said Johanns. "We can now say, based on science, that the prevalence of BSE in the United States is extraordinarily low. The testing and analysis reinforce our confidence in the health of the U.S. cattle herd, while our interlocking safeguards, including the removal of specified risk materials and the feed ban, protect animal and human health."

The estimate of BSE prevalence in the United States is based on data gathered from not only the enhanced surveillance effort that has been underway since June 2004, but also from surveillance conducted in the United States for the 5 years prior. USDA experts used two different methods, the BSurvE Prevalence B method and the Bayesian birth-cohort method, to analyze the prevalence of BSE based on all of the surveillance data.

The findings of the two methods were similar, indicating that the most likely number of cases present in the United States is between 4 and 7 animals. Therefore, USDA concludes that the prevalence of the disease in the United States is less than 1 case per million adult cattle, based on an adult cattle population in this country of 42 million animals.

The testing program is not part of U.S. food safety protections. The system of interlocking safeguards protects animal and public health. The most important safeguards are the removal of specified risk materials from the food supply, along with the Food and Drug Administration's (FDA) 1997 ruminant-to-ruminant feed ban. Science indicates that the longer the FDA's feed ban is in place, the lower the prevalence of BSE will be in this country.

USDA will use the prevalence analysis, once it is peer-reviewed, and international standards set by the World Animal Health Organization, to design an ongoing BSE surveillance program for the United States. The data and analysis will also assist in making science-based policy and regulatory decisions related to the disease.

USDA's enhanced BSE surveillance program followed the detection of BSE in an imported animal in December 2003. The target population of cattle tested included those animals where the disease is most likely to be found if it is present: non ambulatory cattle, cattle exhibiting signs of central nervous disorders or any other signs that may be associated with BSE, including emaciation or injury and dead cattle. Samples were drawn from more than 5,000 locations across the United States, including slaughter plants, renderers, farms, public health laboratories, veterinary diagnostic laboratories and salvage slaughter facilities.

USDA is providing its analysis to outside experts for a scientific peer review and making it available to the public. USDA is confident the conclusions drawn regarding BSE prevalence in the United States are sound and scientifically credible. The analysis, along with a summary report on the BSE enhanced surveillance program, are available at