Variant Creutzfeldt-Jakob disease
Variant Creutzfeldt-Jakob disease (vCJD) is a rare and fatal neurodegenerative disorder caused by prions, which are infectious protein particles. This disease is most commonly linked to the consumption of beef from cattle affected by bovine spongiform encephalopathy, also known as "mad cow disease." The average age for the onset of vCJD symptoms is around 29 years, with a long incubation period of up to 20 years following exposure. Symptoms initially manifest as psychiatric issues, transitioning to neurological impairments, and ultimately leading to severe disability and death, typically within 13 months after symptoms appear.
Diagnosis of vCJD is complex and often requires a combination of clinical evaluations, imaging tests, and sometimes biopsy for confirmation. Unfortunately, there is no cure for vCJD, and treatment is mainly supportive, aimed at improving the quality of life for patients. Preventive measures focus on avoiding potentially contaminated beef products, especially those that include nervous tissue. With over 200 documented cases worldwide, primarily in the UK, discussions around beef safety continue, particularly in relation to food consumption practices. Understanding vCJD is essential for raising awareness about prion diseases and their risks.
Variant Creutzfeldt-Jakob disease
- ANATOMY OR SYSTEM AFFECTED: Brain, muscles, musculoskeletal system, nervous system
- ALSO KNOWN AS: Human mad-cow disease
Definition
Variant Creutzfeldt-Jakob disease (vCJD) is a type of prion disease. Bovine spongiform encephalopathy is a prion disease that affects cows, but there is evidence that this illness can be transmitted to humans, producing vCJD. This illness is often called human 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 the progressive accumulation of prions (infectious protein particles). The central nervous system is progressively damaged as these prions accumulate.
Risk Factors
Exposure to prion-containing tissue is the primary risk factor. Other risk factors include eating beef from infected cows, receiving human growth hormone (HGH) injections before the mid-1980s (changes in the preparation of HGH in the mid-1980s eliminated this risk), working with brain tissue, and receiving a corneal or dura mater (brain lining) transplantation. Five to ten percent of all cases of the nonvariant form of Creutzfeldt-Jakob are inherited.
Symptoms
The average age of persons who get this disease is twenty-nine years old. Rare cases have been reported in children. Once a person is exposed, it can take up to twenty years until symptoms develop. When symptoms develop they usually follow three phases: early phase (zero to six months), in which psychiatric symptoms predominate, including depression, anxiety, withdrawal, memory problems, and difficulty pronouncing words; middle phase, in which neurologic symptoms predominate, including abnormal gait, ataxia (problems with coordination), involuntary movements (muscle jerks and stiffness), and cognitive decline (impaired speech); late phase, in which symptoms include muteness (inability to speak) and immobility. The average length of time from first symptoms to death is fourteen months (with a range of six to thirty-nine months).
Screening and Diagnosis
A clinical history and physical exam are the primary diagnostic tools. If the physician suspects vCJD, additional tests may be needed. These tests include a lumbar puncture (a procedure to collect cerebrospinal fluid), a magnetic resonance imaging (MRI) scan (a scan that uses radio waves and a powerful magnet to produce detailed computer images), a computed tomography (CT) scan (a detailed X-ray picture that identifies abnormalities of fine tissue structure), an electroencephalogram (EEG; a test used to evaluate brain function or disorders), SPECT or PET scans (tests that produce images showing the amount of functional activity in the tissue; used to differentiate vCJD from other diseases), biopsy (removal of a sample of tonsil tissue to test to confirm vCJD), and blood tests and cerebrospinal fluid analysis (which may be used to distinguish this disease from other diseases, such as Alzheimer’s). In many cases, a
Treatment and Therapy
There is no cure for vCJD. Treatment is primarily supportive to maximize patient function and minimize patient discomfort.
Prevention and Outcomes
There have been more than two hundred cases of vCJD worldwide, most of which were associated with beef consumption in the United Kingdom. There is a great deal of controversy regarding the safety of beef in the United States. Only a few cases of bovine spongiform encephalopathy have been detected in the United States, but no cases of vCJD have been attributed to eating beef originating in the United States. To minimize risk, it is generally recommended that people avoid eating beef products, particularly processed meat such as sausage and hotdogs, or beef items containing brain, spinal cord, or bone marrow.
Bibliography
"About Variant Creutzfeldt-Jakob Disease (vCJD)." Centers for Disease Control, 13 May 2024, www.cdc.gov/variant-creutzfeldt-jakob/about/index.html. Accessed 4 Feb. 2025.
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