Variant Creutzfeldt-Jakob disease (vCJD) is a type of prion disease. Bovine spongiform encephalopathy is a prion disease that affects cows; there is evidence that this illness can be transmitted to humans, producing vCJD. This illness also is often called “mad cow disease.”
Causes
Prion diseases are a unique form of infectious diseases. The disease is not produced by a bacterial or viral infection; instead, the illness is related to progressive accumulation of prion proteins. The central nervous system is progressively damaged as these prion proteins accumulate.
Risk Factors
Exposure to prion protein is the primary risk factor. Eating beef from infected cows is a risk factor. There is also evidence that human growth hormone (HGH) injections prior to the mid-1980s was a risk factor, but changes in the preparation of HGH in the mid-1980s eliminated this risk.
Symptoms
Early Phase (0-6 months) – Psychiatric symptoms predominate:
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Depression
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Anxiety
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Withdrawal
Middle Phase – Neurologic symptoms predominate:
Late Phase:
Median duration from first symptoms to death is 13 months ( range 6-39 months).
Diagnosis
The clinical history and physical exam are the primary diagnostic tools. If your physician suspects vCJD, additional tests including lumbar puncture, CT or MRI of the brain, and electroencephalogram (EEG), may be necessary. Biopsy of tonsil tissue has been used to confirm vCJD in some cases. In many cases, final diagnosis requires autopsy and pathologic studies.
Treatment
Currently, there is no cure for vCJD. Treatment is primarily supportive, maximizing level of function and minimizing discomfort.
Prevention
About 150 worldwide cases of vCJD have occurred to date, nearly all associated with beef consumption in the United Kingdom. There is a great deal of controversy regarding safety of US beef. Two cases of bovine spongiform encephalopathy have been detected in the US. No cases of vCJD attributable to consumption of US beef have been detected.
To minimize risk, it is generally recommended that you avoid beef products, particularly processed meat (e.g. sausage and hotdogs), or beef items containing brain, spinal cord, or bone marrow.
RESOURCES:
Creutzfeldt-Jakob Disease Foundation
http://www.cjdfoundation.org
World Health Organization
http://www.who.int
CANADIAN RESOURCES:
What Canadians Need to Know About Mad Cow Disease
Canadian Health Coalition
http://www.healthcoalition.ca/bse.html
Mad Cow Disease
Health Canada
http://www.hc-sc.gc.ca
References:
Dawidowska K. Where’s the (safe) beef? Prevention. 2004;56:34.
Moo-ve over, beef burgers: EN finds many alternatives. Environmental Nutrition. 2004 Aug;27:5.
NINDS Creutzfeldt-Jakob disease information page. National Institute of Neurological Disorders and Strokes website. Available at: www.ninds.nih.gov/disorders/cjd/cjd_pr.htm.
Prusiner SB. Detecting mad cow disease. Scientific American. 2004;291:60-67.
Raloff J. Better protection from mad cow disease. Science News. 2004;165:93.
Smith-Bathgate B. Creutzfeldt-Jakob disease: diagnosis and nursing care issues. Nursing Times. 2005;101:52.
Zeidler M; Sellar R, Collie DA, et al. The pulvinar sign on magnetic resonance imaging in variant Creutzfeldt-Jakob disease. Lancet . 2000;355:1412-1419.
