Mad Cow Disease
Stephen Churchill was 19 when he died in 1995. He was the first recorded victim of a new variant Creutzfeld Jakobs Disease (vCJD or nvCJD), a degenerative brain disease. The disease creates holes in the brain tissue so that the brain resembles a sponge, and nerve cells in the brain are lost.
In March 1996, the British Parliament announced that there is a probable link between vCJD and BSE. BSE, commonly known as the Mad Cow Disease, stands for Bovine Spongiform Encephalopathy.
The possibility of transmission of the disease from cattle to humans sparked a scare about eating beef across the world.
- Mad Cow Disease ... so-called because it affects a cow's nervous system, causing it to behave strangely. They shake and can't stand or walk properly. They also seem nervous, agitated and aggressive.
- Bovine Spongiform Encephalopathy ... so-called because the infected brain tissue became riddled with holes in a sponge-like pattern.
• "Bovine" refers to cattle
• "Encephalopathy" refers to diseases of the brain
• (encephalo = brain; patho = disease).
Here is BBC Special Report on BSE including a chronology of events.
Cause of BSE
What is the biological cause of BSE? No one knows for certain. A possible cause is an abnormal protein called prion ... the abnormal prion attaches to a normal prion and changes it into an abnormal one. The abnormal prions accumulate and form clumps. These kill the brain cells and leave behind holes.
Origin of vCJD?
The story of Mad Cow Disease is a frightening story of transmission of a new disease from one animal specie to another and finally jumping to a totally different specie, humans.
In an attempt to encourage faster growth of cows and to find a use for inedible remains of sheep, farmers began feeding cows with protein supplements made from the internal organs of sheep. This apparently innocent move (i.e., turning herbivores into omnivores) opens the door for the infectious agent of Scrapie (a spongiform encephalopathy) in sheep to cross over to cattle.
In 1986, a number of British cattle came down with a new illness called Mad Cow Disease (which is strikingly similar to Scrapie). After the cattle died, their carcasses and offal were included in the same protein supplements and this may have aggravated the epidemic.
- Scrapie ... so-called because infected sheep rub their bodies against walls and fences until the skin is completely raw.
Subsequently, people who ate British "processed beef products" have been found with vCJD ... a deadly food chain from sheep to cattle to humans.
Both vCJD and Mad Cow Disease are not contagious (i.e., it cannot be spread directly from one cow to another or from one human to another). The only known way a human can become infected with vCJD is through the transmission of the abnormal prions by eating infected meat.
The meats most likely to contain abnormal prions are processed beef products including hamburgers, hot dogs, sausages and luncheon meats because these generally contain meat from different parts of the animal. The brains, eyes, spinal cords, bone marrow and intestines of cows are believed to have a higher risk of carrying prions. Beef muscle and milk appear to be safe. According to deputy director of Singapore's Agri-Food & Veterinary Authority (AVA), Dr Paul Chiew, there is no way to test for prions in muscle (Source: Mind Your Body, health companion from The Straits Times, February 22, 2006).
BSE Fact Sheet |
The Brain Eater
Information compiled in February 2006 by "Parenting the Next Generation"
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