Biology 202
2004 Second Web Paper
On Serendip

It comes inconspicuously, through family genes, random mutation of bad luck, or even from contaminated body masses. Creutzfeldt –Jakob disease (CJD), named after the two men who discovered the pattern of its symptoms in the 1920's, is a disease in which the brain rapidly deteriorates and holes being to form within its structure. (1,2,3) It is the long incubatory period, though, of Creutzfeldt - Jakob disease (CJD) which makes it particularly hard to track and treat. The relation CJD has to the epidemic in Europe regarding Bovine Spongiform Encephalopathy (BSE) is crucial. BSE caused the deaths of nearly 200,000 heads of cattle, and a new variant of the disease emerged. (3) ) Despite the new scientific understanding of both diseases, a great deal of misinformation has been spread, and the fear of Mad Cow Disease has permeated the culture of Europe and many other countries. There is a difference between these two neurological degenerative disorders - BSE related vCJD and CJD - but this distinction is rarely clear to those without medical training; the relative lack of information, combined with its grim diagnosis has led many citizens and governments to a skewed perception of what the disease truly is.

In the early 1990's, when scientists and doctors began to notice a pattern of spongiform illness in patients in England, they looked at CJD as a possible cause for this believed "outbreak." However, when former cases of CJD were compared to the new cases, a difference was noticed. The age of the afflicted had dropped drastically; those who had this "new" illness were young, primarily under the age of 40. Typically, CJD occurred in older populations, predominantly those over fifty years of age. (1, 2, 3, 6) Even the course of the variant was longer; it would typically last longer within patient than CJD, but shared similar neurological symptoms. However, in the initial stages, CJD patients typically developed neuromuscular coordination problems as well as personality changes. In vCJD, by way of contrast, psychological symptoms appear first, such as depression and anxiety, later progressing to neurological degeneration. (2) Both have similar neurological consequences, but researchers determined that this vCJD was not necessarily the natural or identical genetic type as classic CJD.

Neurologically, CJD is one of the most devastating diseases of the brain. Photographs of CJD patient's after autopsies show a grim picture; a brain that has literally been eaten away, pockmarked with holes. (9) Symptoms begin suddenly after remaining dormant anywhere from 5 to 40 years, and rapidly degenerate the brain and body. The beginning stages start as mild dementia and possible psychological problems, with confusion and memory loss the most commonly found, along with loss of muscular control. Quickly, it proceeds to dyesthesia, a condition which causes pain sensations in areas such as the face or limbs, and severe mental impairment and muscle spasms known as myoclonus. Often, CJD patients lose their ability to speak, and much of their immunity, and become susceptible to illnesses such as pneumonia. At the peak of the symptoms, those suffering from the disease lose the ability to control themselves physically, have severe dementia or mental impairments, and commonly lapse into comas. (2) It is this rapid downward progression of the symptoms that make the disease so fatal, as death generally occurs one year after the onset of the disease, and approximately two years for vCJD.

Treatment today for the disease remains unclear; there is no physical way to prevent the brain from deteriorating, and all medical professionals can do is lessen the symptoms and pain associated with it. Even diagnosing CJD or vCJD is still very primitive, a brain biopsy or physical exam of the brain at autopsy has been the only proven way to tell. A promising new method of detection has come out using spinal cord fluid, but only detects the disease once visible symptoms have developed; meaning preventative treatment is still too late. In a recent study, scientists found that nearly 13% of diagnosed Alzheimer's patients after autopsy were actually suffering from CJD, showing that the symptoms can appear from many neurological degenerative diseases. (8) Even with modern technology and medicine, CJD and its variants can still not be cured, nor can it always be detected or diagnosed.

The disease itself though, is not what one typically associates with transmissible diseases; it's neither a virus nor bacteria. In early studies, it was believed to be a "slow virus," meaning there existed an extended period of time between the onset of infection to the progression of visible symptoms. More recently, scientists have found that abnormally shaped prions, which are protein structures within the body, are the probable cause for transmissible spongiform encephalopathy (TSE) disease. ((4)) It is when this prion becomes mutated and folded, becoming infectious, that the TSE will occur. It is now believed that these prions, random mutations of proteins, create the degeneration within the brain, forming holes and gaps that are so indicative of TSE. (1, 5)

CDJ has progressed relatively rapidly through human populations. There are three different ways in which one can become infected. In 85 to 90% of all cases, it is a sporadic and random mutation which leads to the disease. However, there is a certain genetic link to CJD, and approximately 5 to 10% of reported cases occur in someone with a familial connection to CDJ. However, the infected prion must have been altered within the gametes for it to be passed along. The last and most uncommon way of transmission is know as iatrongenic, which accounts for 1% of CJD cases. (1) This occurs when there is direct contact with CJD contaminated instruments or body matter. Formerly, cornea or dura matter grafts, the use of natural growth hormones, and unsterilized surgical tools could have possibly transmitted the disease. Now, because of the more controlled and sanitary settings in medical facilities, and the use of synthetically derived hormones, this way of transmission has become increasingly unlikely. With the different possibilities of becoming infected though, health associations still only estimate CJD occurs in approximately one out of every million people. (3)

However, for the variant CDJ, the prospects of the methods of transmission are much more frightening and unusual. When an outbreak of the prion related disease Bovine Spongiform Encephalopathy (BSE) occurred in mid 1980's in Great Britain, the only concern was the removed the cattle diagnosed with the disease. But when a large number of TSE cases became present in early 1996, scientists and residents became increasingly worried about the health of the population. As the two forms of spongiform diseases were compared, a strong similarity of the prions was seen and a theory developed as to how it this variant could be explained. The theory was that consumption of the beef products from cattle tainted with BSE could result in the formation of a spongiform illness within humans. The cattle could develop BSE from eating mixtures of scraps not fit for human consumption from the nervous system of ruminants, or other large, grass eating mammals. (3, 6) Despite no significant or direct proof that this was the cause of the illness, Great Britain and Europe erupted into a frenzy of fear. Imports of British cattle were banned, and people stopped eating beef out of the fear they would get "Mad Cow Disease." But from statistics, only between 140 to 155 cases of actual vCJD have been confirmed or suspected in the population. (7)

Yet, even with these relatively low numbers that are comparable to the infection rate of CJD, Europe, Japan, and the United States have all taken extraordinary measures to "prevent" transmission of the disease. Sanctions on importation of beef and blood donations have been put into place to "reduce the number of cases" of the disease. By restricting donations of blood by people who have spent three or more months in Europe since 1980, the United States and other countries are putting themselves at risk for a blood shortage, even when CJD and vCJD have not been proven transmittable through the lymphatic system. (2) But because of the long incubatory period of both forms of CJD, and the inability for scientists to detect the disease before symptoms, these preventative measures may still not protect the populations from the minor risks of the disease.

The undetecability and lethality of CJD and vCJD are what have created the uproar within many cultures and countries, leaving behind fear and confusion of what the disease truly is. With much of the disinformation still being given freely, fears of the public have not subsided, causing drastic actions, such as mass slaughter of cattle, with many restrictions still remaining on the cattle industry and in blood donation because of the risk of CJD or vCJD. In understanding what the diseases are, the differences between the original and variant CJD, and the transmission and symptoms of both, the misinformation of the people can be corrected and the worries subsided. However, this goal by the medical community to try and inform the public has been a difficult task. Many people are still not ready to accept what CJD and vCJD are and how they occur, and will not change their marked beliefs regarding CJD, allowing the disease to further become an issue of global politics, media, and what the public would like to believe.

References

2)Creutzfeldt Jakob's Voice; The CJD Voice's site, with information and many interesting links.

3)WHO Site; The World Health Organizations site with information regarding the global impact.

4)Kuru and TSE; A site describing Kuru, another TSE associated with cannibalism.

5)Encylopedia definition; The encyclopedia definition of what prions are

6)Massachusetts Health Department; The Massachusetts State information guide to CDJ and Mad Cow Disease.

7)Statistics and Numbers of CJD; The statistics of CJD prevalence.

8)Alzheimer's and CJD; A site describing the misdiagnosis of CJD as Alzheimer's.

9)Photograph comparing brains; A photograph of a brain suffering from a TSE compared to a normal brain.


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