Occasional news about mad cow disease has caused concern among some parents about buying meat. However, the chance of getting mad cow disease appears to be much smaller than parents may think.
Mad cow disease is the commonly used name for bovine spongiform encephalopathy (BSE). It is one of a number of prion diseases. Prions are a type of infectious particle. Prion diseases are progressive, degenerative infections that affect the central nervous system of cattle. They can be spread to humans who eat the beef of an infected animal or come into contact with tissues of infected animals. The cattle themselves become infected with BSE by eating feed contaminated with the BSE organism. The cattle develop brain disease that results in death. When humans get the disease, it causes a variation of Creutzfeldt-Jakob disease (CJD) called variant CJD (vCJD), which is a fatal brain disorder.
Millions of cattle have been destroyed in Europe since the first cases of mad cow disease appeared in the 1980s. The first BSE case in a dairy cow in the United States was identified by the Department of Agriculture in December 2003. The Food and Drug Administration and other federal agencies have regulations in place to prevent contamination of the US food supply with BSE. At present, the risk of getting BSE from beef available in the United States is considered extremely low.
Worldwide, BSE-related illnesses remain very rare in humans. Through December 2003, there were a total of 143 cases of vCJD reported in the United Kingdom, plus 6 cases in France and 1 each in the United States, Canada, Italy, and Ireland. A person can also become infected if he receives a transplant from someone with the disease or a child receives a growth hormone that was made from the pituitary gland of an infected person. Note that growth hormones are now manufactured rather than taken from human bodies.
Signs and Symptoms
People with mad cow disease can have very serious signs and symptoms, including personality changes, muscle stiffness, involuntary muscle movements, dementia, and seizures. The disease can affect individuals at a younger age than those with traditional CJD (a median age of 28 years in vCJD, compared with 68 years in classic CJD). Most cases have occurred in adults, but an occasional case has been seen in teenagers. The traditional form of the disease has a hereditary basis. Both diseases involve abnormal proteins that accumulate in the brain.
How Is the Diagnosis Made?
The signs and symptoms of vCJD will help your pediatrician make the diagnosis. However, the only way to definitively diagnose any human prion disease is to examine the brain tissue itself.
No treatment is available to slow down or stop the progression of mad cow disease or other prion infections. Studies are currently taking place to investigate a number of experimental treatments.
What Is the Prognosis?
Mad cow disease is fatal. The incubation period for disease related to exposure to infected tissues varies between 1.5 years and more than 30 years.
There is no evidence that cooking contaminated meat will destroy the BSE organism. Government regulations of the beef industry make the risk of transmission of BSE to people very unlikely.