Creutzfeldt-Jacob disease (CJD), also known as a transmissible spongiform encephalopathy (TSE), is a rare degenerative neuro-disease in humans (1). It is fatal (1). There are three categories of CJD: iatrogenic, inherited, a sporadic. The etiologic agent is thought to be prions, or proteinaceous infectious particle (3). Prions are unconventional proteins (3), with no nucleic acid compound (4). Theoreticaly, prisons transform normal protein molecules into infectious ones by changing the shape of the healthy protein molecules (3).
First, iatrogenic CJD is acquired through direct exposure to infected human tissue (3). For example, cornea, dura mater transplants, or injection of natural human pituitary growth hormones (1). Second, sporadic CJD's cause is unknown (6). Third, familial CJD can be inherited (6).
The reservoirs identified for iatrogenic infection are contaminated human tissue or instruments used in neuro-invasive procedures (4). These cases are rare. Less than 5% of CJD cases have been iatrogenic (1). 5-10% of the cases are familial and 85% of the cases are sporadic (6). There is still debate over the connection between bovine spongiform encephalopathy (BSE), mad cow disease, and CJD (3). It is unknown whether BSE is transmitted to humans from cattle (4).
The diagnosis of CJD is very difficult (1). This disease can often be mistaken for a psychological illness or neurological disorder (3). The disease does not present with fever or other flu-like symptoms (6). Before the onset of symptoms, there are no reliable diagnostic tests for confirming a diagnosis (1). Magnetic resonance scans (MRI), tonsillary biopsy, electroencephlogram and cerebrospinal fluid tests have been helpful, but do not provide a definitive diagnosis (3). Currently the only reliable test for confirming CJD is pathological examination of the brain (1). A brain biopsy or autopsy must be performed (5). Microscopic examination of the brain tissue reveals "floral plaques"(1). Floral plaques are "multiple microscopic and abnormal aggregated encircled by holes…resulting in a daisy-like appearance"(1).
The initial stage of CJD is characterized by symptoms of insomnia, depression, confusion, personality changes, behavior changes, impaired memory, and impaired vision (6). As the disease progresses, a rapid, progressive dementia and myoclonus characterize it. In the final stages of the disease, mental impairment is severe (6). All mental and physical function is lost (3). The patient lapses into a coma and usually scum to pneumonia and other infection (6). The duration of CJD from the onset of symptoms to death is approximately one year (6).
There is no treatment or cure for CJD (4). The disease is fatal (2).
To reduce the risk of transmission of CJD from one person to another, people with a history of the disease should never donate blood, tissue, or organs (6). Healthcare workers should use universal precautions (6). Changes in the processing of cattle feed have been made to reduce the potential risk of exposure of humans to BSE (1). Also, the replacement of natural human growth hormone with recombinant growth hormone has eliminated the risk of infection (5).
Currently the World Health Organization has held meeting with an emphasis on transmissible spongiform encephalopathies to help protect people (5). Also, many government and public/private organizations are reshearching CJD (3). These groups are focusing on prions and how they infect and destroy the brain (6). The goal is to develop test to diagnose and treat CJD (6).
References:
1. World Health Organization. "Variant Creutzfeldt-Jakob Disease".6/2001.URL:http://www.who.int/inf-.fs/en/fact180.html accessed on 11/27/01
2. Baumbach,Gary. "Parenchymal Infections: Prions".URL:http://www.vh.org/Providers/TeachingFiles/CNSInfDisR2/Text/Pinf.CDE.html accessed on 11/27/01
3. Creutzfeldt-Jakob Disease Foundation. " Creutzfeldt-Jakob Disease". URL:http://cjdfoundation.org/CJDinfo.html accessed on 11/27/01
4. Poidinger,Michael. "Prions".URL:http://www.uq.edu.au/vdu/prions.htm accessed on 11/28/01
5. World Health Organization. "Bovine Spongiform Encephalopathy".6/2001.URL:http://www.who.int/inf_fs/en/fact113.html accessed on 11/27/01
6. National Institute of Neurological Disorders and Stroke. "Creutzfeldt-Jakob Disease Fact Sheet".07/01/01. URL:http://www.ninds.nih.gov/health_and_medical/disorders/cjd.htm accessed on 12/10/01