Mad Cow Disease

The critical information
In December, 2003, the U.S. Department of Agriculture (USDA) made a preliminary diagnosis of Mad Cow Disease, bovine spongiform encephalopathy (BSE), in a single dairy cow in Washington state. Subsequent tracing found that the cow came from a herd in Canada and resulted in additional attempts to find and quarantine other cows from the heard of the infected cow. The word from the USDA is that the safety precautions in place worked and there was no real danger to the U.S. food supply. And, as a result of the BSE crisis, the guidelines for slaughter of beef have been strengthened.

What is bovine spongiform encephalopathy?
Bovine spongiform encephalopathy (BSE) is a progressive neurological disorder of cattle resulting from infection by an unconventional transmissible agent. Animals affected with mad cow may display nervousness or aggression, abnormal posture, lack of coordination, decreased milk production or loss of body weight despite continued appetite. The disease's incubation period ranges from two to eight years. Following the onset of symptoms, the animal's condition deteriorates for a period of two weeks to six months until death.

The nature of the transmissible agent is unknown. Strong evidence indicates that BSE has been transmitted to humans primarily in the United Kingdom, causing a variant form of Creutzfeldt-Jakob disease (vCJD). vCJD begins subtly with forgetfulness, depression, personality changes, strange physical sensations and problems with eyesight. It rapidly progresses to dementia, jerking muscles and blindness. The course of the disease usually takes only four to six months from the onset of symptoms to death.

How great is the risk to humans?
A substantial "species barrier" appears to protect most humans from becoming ill. This is evidenced by the relatively small number of people who became ill in the United Kingdom in spite of infection in over 1 million cattle since BSE was identified since 1989. As of December 1, 2003, a total of 153 vCJD cases had been reported worldwide (during 2003). Of these, 143 cases had occurred in the United Kingdom and Canada. The risk to human health from BSE in the United States is extremely low.

An important protection against BCE is the USDA surveillance program. As soon as the BSE case was identified in December, 2003, the most recent case, both USDA and FDA activated their BSE Emergency Response Plans and USDA immediately recalled the meat. Meat that did enter the food supply was quickly traced and was removed from the marketplace. Scientific research indicates that muscle meat is not a source of infection and the organs that do carry the infection did not enter the food supply. According to the FDA, there is no significant risk from meat or milk products of this infected animal.

Reduce your risk
To reduce the risk of acquiring vCJD from food, travelers to Europe should consider avoiding beef and beef products or selecting solid pieces of muscle meat that are less likely to be contaminated than beef products such as burgers and sausages.