Mad cow disease is just one of many transmissible spongiform encephalopathies, or TSEs. TSEs attack the brain, with symptoms ranging from dementia to psychosis and paralysis. TSEs are fatal and untreatable.
Evidence shows a relationship between the cattle disease bovine spongiform encephalopathy (BSE), or mad cow disease, and the human disease Creutzfeldt-Jakob disease (CJD). Experts believe that both mad cow disease and Creutzfeldt-Jakob disease are caused by prions-normal protein molecules that become infectious when folded into abnormal shapes. These prions are transmitted to humans through the consumption of beef.
While approximately 200,000 cases of mad cow have been confirmed in the United Kingdom, no cases of mad cow have been confirmed in the US. Because the use of infected cattle tissue in cattle feed was probably responsible for the outbreak in the United Kingdom and the consumption of beef may cause the transmission of mad cow to humans, the US Food and Drug Administration instituted a ruminant feed ban in June 1997. Therefore, it is very unlikely that mad cow disease will be a food borne hazard in the United States.
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 until it dies or is destroyed. This usually takes from two weeks to six months.
CJD begins subtly with forgetfulness, depression, personality changes, strange physical sensations and problems with eyesight. It rapidly progresses to dementia, jerking muscles and blindness before leading finally to death. The course of the disease usually takes only 4 to 6 months from the onset of symptoms to death.
Is it safe to travel to Europe? To reduce the risk of acquiring CJD 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. Milk and milk products from cows are not believed to pose any risk for transmitting mad cow disease.