Bovine Spongiform Encephalopathy (BSE) and Variant Creutzfeldt-Jakob Disease (vCJD)

          Bovine Spongiform Encephalopathy, otherwise known as Mad Cow Disease, is a neurodegenerative disease that ultimately results in death. BSE is an infectious disease caused by abnormal prions that affact the brains and spinal cords of the diseased cattle. It is believed that this originated from a disease in sheep known as Scrabies. This disease is also characterized by abnormal prions. These infected sheep were slaughtered and put into bone meal to provide a source of calcium for the cattle; however, this carried the disease to the cattle. Humans can contract the human form of Mad Cow Disease, known as Variant Creutzfeldt-Jakob Disease (vCJD) by eating beef from the diseased cattle. This leads to a prion abnormality in the human. They then have a neurodegenerative disease that eventually will kill them as well. (1)

Bovine Spongiform Encephalopathy (BSE)

     Bovine Spongiform Encephalopathy refers to the changes seens in the brain tissue and spinal cords of affected cows. This disease is transmitted due to proteins in the brain known as prions. Normally, prions help with nueral development and function throughout the body which leads to establishing memory. The abnormal prions develop throughout the nervous system of the cattle. Therefore, these prions appear to be the particle that transmits the infectionous disease. These molecules stick togethere and clump in the nervous system tissue, resulting in tiny sponge-like holes in parts of the brain. The spongy holes cause slow deterioration within the cow's brain that then travels to the rest of the body via the spinal cord. (2)

     The SYMPTOMS of Mad Cow Disease include:

  • Change in behavior
  • Gradual uncoordinated movements
  • Trouble standing and walking
  • Weight loss without decrease in appetite
  • Decrease in milk production (2)

          

These symptoms can begin at any random time; however, once they start, its downhill from there.

          

          

          BSE originally originate from the United Kingdom. Almost 200,000 cattle were affected among the UK. In 1993, the BSE cases reached an all-time high with 1,000 cases each week. Twenty-three Mad Cow Disease cases have been confirmed in North America, with nineteen in Canada and four in the United States. One of the infected cows that died in the US was born in Canada, while the other three cases in the US were cows that were imported from Canada. The four cases in the US were in Washington in 2003, Texas in 2005, Alabama in 2006, and California in 2012. (3)

          The United States Department of Agriculture (USDA) developed a plan of action to put an end to this horrible disease that has been transmitted from sheep to cattle and now to humans.

     The USDA:

  • Prohibited farmers to use feed that included other animal parts

    "Cows too weak to stand at slaughter can no longer be sold as beef" (4)

  • Banned imports of cattle and cattle products
  • Outlawed risky feed ingredients
  • Constructed random testing of cattle in the US

Variant Creutzfeldt-Jakob Disease

          The human form of BSE is known as Variant Creutzfeldt-Jakob Disease (vCJD). A new study has shown that the same infectious protein, known as a prion, that causes Mad Cow Disease is also responsible for causing vCJD. Variant Creutzfeldt-Jakob Disease is a very rare disease; however, once a person has vCJD the person will die in a matter of time. vCJD has occured in 160 people world-wide. This disease can appear between the ages of twenty and seventy. Yet, it normally occurs in the late fifties. (5)

     The SYMPTOMS of Variant Creutzfeldt-Jakob Disease include:

  • Unsteadiness in walking
  • Banned imports of cattle and cattle
  • Outlawed risky feed ingredients           
  • Constructed random testing of cattle in the US (5)

          As of December 1, 2003, a total of 153 cases of vCJD had been reported in the world. Just as Mad Cow Disease is most dominant throughout the United Kingdom, the UK also has the most cases of vCJD with 143. There are six vCJD cases from France and one from Canada, Ireland, Italy, and the United States. (6)

          

Conclusion

          Both BSE and vCJD are fatal diseases. Therefore, once the sympotoms begin in the cow or human, it is only a matter of time. In order to elliminate the chances of contracting vCJD from cattle who have BSE, avoid meat that may contain nervous system tissue and choose beef from cows that have been grass fed rather than fed bagged feed that may contain bone meal. Fortunately, due to legislature, BSE and vCJD are becoming diseases of the past. (7)

 

 

References

(1) Introduction

(2) Bovine Spongiform Encephalopathy

(3) BSE Statistics

(4) USDA and BSE

(5) Variant Creutzfeldt-Jakob Disease

(6) vCJD Statistics

(7) Conclusion

 

Brody Wood and Alyssa Stoddard

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