To test for BSE, brain tissue from a suspected animal is injected into an experimental animal. Scientists then observe the experimental animal for signs of BSE. With the advent of the prion hypothesis, molecular tests are being developed to detect abnormal prions in suspected animals. One company, Prionics Inc., has marketed diagnostic tests for BSE.
Control and Prevention
In 1988, the UK government banned using any ruminant (cattle, sheep, goats) or ruminant by-products in animal feed. Later, they banned exports of cattle to other countries. They have destroyed BSE-infected cattle and monitored herds for signs of BSE. In addition, the medical community has monitored the general population and reported any cases of nvCJD. These steps have contributed to a steady decline in BSE since 1992.
The U.S. government has instituted the following policies regarding BSE:
- The U.S. Department of Agriculture (USDA) has prohibited imports of live ruminants or ruminant products (meat, feed, by-products) from Europe.
- The USDA has tested any cattle showing abnormal behavior for BSE.
- The USDA inspects all cattle used for food for signs of neurological diseases. Cattle with unidentified neurological disorders are rejected.
- The U.S. Food & Drug Administration (FDA) has prohibited using mammalian proteins in making animal feeds for ruminants.
- The FDA has recommended that pharmaceutical companies should not use animal tissues from countries with BSE in making drug products (vaccines).
- The FDA has asked blood centers to exclude potential blood donors who have spent six or more consecutive months in the UK between 1980 and 1986.
- The Centers for Disease Control (CDC) regularly monitors the U.S. population for signs of nvCJD.
- The CDC has issued guidelines to travelers in Europe -- 1. Avoid beef and beef products altogether. 2. If eating meat, then select beef or beef products that have less opportunity for contamination from nervous tissue (solid muscle cuts vs. processed sausages or hamburgers. 3. Milk or milk products are not believed to pose any risk from the BSE agent.
- The National Institutes of Health (NIH) conducts research on BSE, CJD, nvCJD and related nervous system diseases.
Several U.S. government agencies (FDA, USDA, CDC) monitor the meat supply in the United States as well as imports from other countries. European countries have instituted similar guidelines.
For more information on BSE and related topics, see the links on the next page.