Many people have concerns about the safety of beef in the United States in the wake of another cow testing positive for bovine spongiform encephalopathy (BSE), also known as mad cow disease. The American beef supply is safe.

First, you should understand that BSE has never been diagnosed in any cattle less than 30 months of age. The majority of cattle enter the food chain in our country when they are between 18 and 24 months old. That's one reason the U.S. Department of Agriculture has not mandated testing of every animal slaughtered.

The brain, spinal column and other nervous tissue of infected cattle have been shown to contain the causative agent for BSE. This agent is not found in muscle tissues, such as steaks, roasts and the like. The USDA has banned central nervous system material and portions of the intestines from all harvested cattle entering the food supply to further reduce the chance of introducing the causative agent into the nation's food supply.

The USDA has taken another corrective step by banning what is known in the industry as downer cattle. The majority of these animals become downers because of injuries during transport. Some may be sick. The best way to ensure the food supply remains safe is to ban downer cattle from the human food supply. Downer cattle are humanely euthanized and the remains destroyed.

The USDA continues to pursue the implementation of a national livestock identification program. The intent is to develop a national ID system to trace any animal within 48 hours.

While BSE is associated with cattle, other ruminants (animals with multiple stomachs) have similar diseases common to them. These include scrapie in sheep and chronic wasting disease in deer and elk.

Less than 160 individuals have been diagnosed with a form of Creutzfeldt-Jakob disease that appears to be similar to BSE in cattle. CJD is a devastating, terminal disease, but the risks of contracting it are remote. A person is more likely to be struck by lightening than to contract CJD.

Death from this form of CJD is far less likely to occur than from other food pathogens such as listeria, salmonella and E.coli 0157:H7. For example, listeriosis, associated with contaminated meats, dairy products and raw vegetables, and salmonellosis, most often linked with eggs, cause slightly more than 500 deaths a year in the United States-out of a population of more than 300 million.

Those who have questions or need additional information, can call the Clarke County Extension office (251-2753121).