Alternative Names bovine spongiform encephalopathy, Variant Creutzfeld-Jakob disease
Definition Mad cow disease, also called bovine spongiform encephalopathy, causes decay in the brain. It is known to affect cows and it is thought to cause disease in people, too.
What is going on in the body? The disease causes a type of organism known as a prion to build up in the brain. This prion build up causes brain injury and degeneration.
Creutzfeldt-Jakob disease (CJD) is a human prion disease. Mad cow disease is seen in cows and is now thought to cover varient CJD in humans.
In 1996, this variant occurred in a number of people in the United Kingdom, some younger than the age group usually affected by CJD.
A strong link between mad cow disease and the variant of CJD is now suspected. Most believe that this variant CJD is the human form of mad cow disease.
What are the signs and symptoms of the disease?
fatigue and disordered sleep
memory loss and confusion
psychiatric and behavioural problems
altered sensation
difficulty with walking and movement
vision loss
difficulty talking
paralysis
What are the causes and risks of the disease? The cause of prion diseases is prion proteins.
These prion diseases are thought to be spread by eating infected tissue, such as beef from a cow with mad cow disease. Another method may be by contact with infected tissue through broken skin or mucous membranes. Some people are at greater risk for prion disease because of heredity. Specific risk factors for variant CJD are not known.
What can be done to prevent the disease? The recent outbreak of variant CJD in the United Kingdom may have been due to people eating beef from cows with mad cow disease. It is possible, though not proven, that avoidance of eating meat may have prevented this outbreak.
How is the disease diagnosed? A final diagnosis can be made with a biopsy of the brain. This involves taking a small piece of brain tissue with a special needle. The piece of tissue can then be examined with a microscope. At death, an autopsy will also show specific changes in the brain.
What are the long-term effects of the disease? Brain degeneration and death are the final results of mad cow disease.
What are the risks to others? Mad cow disease is not thought to be contagious. Exposure to the internal organs of an animal with mad cow disease may transmit this disease, but this has not been proven. It should be noted that this disease is very poorly understood. There is much debate over whether or not it can be passed to humans at all. People who are cannibals in remote parts of the world have been shown to get other prion diseases from eating infected people's brains.
What are the treatments for the disease? There is no treatment for this disease. Some medications may be useful to reduce symptoms, such as psychiatric or behavioural problems.
What are the side effects of the treatments? All medications have possible side effects. These may include allergic reactions and stomach upset. Specific side effects depend on the drugs used.
What happens after treatment for the disease? Death usually occurs within 2 years of when symptoms start.
How is the disease monitored? Symptoms and physical examination are followed to see if any new medications to treat symptoms may be needed.
Author: Danielle Zerr, MD Reviewer: HealthAnswers Australia Medical Review Panel Editor: Dr David Taylor, Chief Medical Officer HealthAnswers Australia Last Updated: 1/10/2001 Contributors Potential conflict of interest information for reviewers available on request
