[4H; Mad Cow Disease]^________

DO YOU KNOW?

- As of November 2006 there were 200 individuals worldwide diagnosed with mad cow disease.

Creutzfeldt-Jakob disease (CJD) itself is pretty rare each year, only one in 1 million people in the United States die of the disease.

- In 1996, Oprah Winfrey broadcast a show about mad cow disease and told her viewers that new information about the disease “just stopped me cold from eating another burger.” In response, a Texas cattlemen’s association sued Winfrey, claiming her comments led to an 11-million-dollar loss for the beef industry. In the end, he jury ruled in favor of Oprah.

- In 1997, Dr. Stanley Prusiner won the Nobel Prize for his discovery of the prion proteins that cause transmissible spongiform encephalopathy diseases like BSE.

What have you learnt? Try this quiz!

Symptoms

Experts do not yet know exactly how long the incubation period is for VCJD. However, they do believe that it takes years, if not decades, from the time someone is exposed to the disease until the first signs appear. After the first signs appear, the brain can deteriorate within a year.

Infected Human
BSE affects the brain. Since Creutzfeldt-Jakob disease affects the brain, the symptoms it produces are neurological.

In the early stage, it may start out subtly with insomnia, depression, confusion, personality and behavioral changes, and problems with memory, coordination, and sight.

As it progresses, within 4 months of the disease onset, the person rapidly develops dementia and involuntary, irregular jerking movements called myoclonus.

In the final stage of the disease, the patient loses all mental and physical functions, lapses into a coma, and eventually dies. The course of the disease usually takes one year.

The disease affects all age groups and is very hard to diagnose until it has nearly run its course. As Variant Creutzfeldt-Jakob disease is called "variant", it affects people at very young age, even teenagers. Hence the ages ranged from 18 to 53 years old.

Infected Cattle
Infected adult cattle may develop signs of the disease slowly. It may take from 2 to 8 years from the time an animal becomes infected until it first shows signs of disease. Symptoms in the animal include a change in attitude and behavior, gradual uncoordinated movements, trouble standing and walking, weight loss despite having an appetite, and decreased milk production. Eventually the animal dies. From the onset of symptoms, the animal deteriorates until it either dies or is destroyed. This disease process may take from 2 weeks to 6 months.

Preventions - How to avoid contracting mad cow disease?

Mad Cow Disease can be prevented by:

1. Eat poultry and fish, or choose a vegetarian diet.

2. Avoid beef products that may contain bits of spinal cord or brain tissue. These include ground beef, sausage, and hot dogs. Solid pieces of muscle meat are less likely to be contaminated. Bone-in cuts such as a T-bone steak and intestine are more risky.

3. When beef is processed or cooked removing the parts of the cow that are at highest risk of containing BSE-causing proteins — the brain and spinal cord — to reduce the chances of contaminating the meat people eat.

4. If travelling to countries where BSE has been detected, such as the United Kingdom, Europe, Portugal, and Spain, do not eat beef. Avoid having a blood transfusion overseas.

PREVENTION IS BETTER THAN CURE!

Treatment - What are the solutions to mad cow disease?

Variant Creutzfeldt-Jakob disease is a brain disorder which becomes deadly over time and has no cure. No treatment that can cure or prevent the progression of Creutzfeldt-Jakob disease has yet been discovered, as the prions is not able to be destroyed by cooking, irradiation, or any other type of disinfection.

However, we all can manage the symptoms that develop as the disease progresses. People who are infected may be asked to stop taking any medications that could affect their memory or cause confusion and may be referred to specialists in neurology and infectious disease to provide medications to ease the symptoms. Laboratory testing is looking at a number of medications to prevent development of prion disease in animals.

Global impacts – How does Mad Cow disease affect the world?

The BSE outbreak in England was responsible for the death of nearly 200,000 cattle, and led to the pre-emptive slaughter of 4.5 million non-infected cows. This loss is clearly devastating to the English agricultural sector and it cost over $2m to handle the disease.
The impact of the mad cow epidemic on global markets has been huge. Several countries have closed their borders to European, British, American and Canadian beef imports for years. Japan, for example, was formerly the largest importer of U.S. beef, buying over one billion dollars worth in 2003. When the first American case of BSE was identified in December that year, Japan halted all imports from the U.S., diminishing exports by over 50 percent in this country.

Catch a mad cow in action here!

Useful Websites!

MADCOW 1 - Mad Cow Disease Overview
MADCOW 2 - Mad Cow Disease and Humans
MADCOW 3 - More about Mad Cow Disease!
MADCOW 4 - Neuroscience For Kids
MADCOW 5 - How Stuffs Works
MADCOW 6 - Wikipedia
4H - The Human Eye

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What is Mad Cow Disease?

Mad cow disease is an incurable, fatal brain disease that affects cattle and possibly some other animals, such as goats and sheep. The medical name for mad cow disease is Bovine Spongiform Encephalopathy (pronounced: bo-vine spun-jih-form en-seh-fah-la-puh-thee), or BSE for short. It is called mad cow disease because it affects a cow's nervous system, causing a cow to act strangely and lose control of its ability to do normal things , such as walking.

Origins - Where and When?

BSE was initially recognized in cattle in the UK in 1986. It is initially thought to have come from a similar disease in sheep called scrapie . In the 1980s, producers of cattle feed changed the way they processed feed. The change somehow allowed the scrapie disease agent to survive the cattle feed production process. Thus, contaminated food was fed to cattle, which then came down with BSE. At the time, neither scrapie nor BSE were thought to affect humans. So, meat from BSE-infected cows made it into the food supply. Humans who ate the infected meat contracted the BSE-causing agent and developed VCJD.

Causes

BSE is spread by contact with brain or other nervous-system tissue from an infected individual. Contact can be from eating food or food by-products that have been contaminated with nervous tissue, or from instruments that have contacted diseased nervous tissue. Once the infectious agent enters the brain, it can lie dormant for several years. When activated, the agent kills brain cells, leaving large areas of spongy holes. Also, large clumps of abnormal prion proteins (plaques) are found in brain cells. Once the agent is activated, the disease runs its course in less than one year, and ultimately results in death.

Refer to "Symptoms" for more information.

We do not know the agent that causes BSE, but we do know the following:

• The agent must be small ,even as small or smaller than a virus!

• It cannot be killed it by cooking or freezing - Much higher temperatures than those used in cooking or sterilizing are required to kill it.

• Disinfectants do not work - Normal chemicals that are used to disinfect surfaces for bacteria and viruses (Lysol, Betadine) are not effective.

• It does not appear to have genetic information (nucleic acids)

How does Mad Cow Disease spread?

From Cow to Cow
BSE does not spread naturally from cow to cow; it is suspected to be transmitted by feeding cows animal meal that contain infected tissues . The type of protein, called prion , that causes mad cow disease cannot be removed or destroyed once contracted.

From Human or Cow to Human
Humans cannot get mad cow disease. But in rare cases they may get a human form of mad cow disease called Variant Creutzfeldt-Jakob disease (VCJD), if they eat the nerve tissue , such as the brain and spinal cord of cattle that were infected with mad cow disease or eat food contaminated with VCJD.

Variant Creutzfeldt-Jakob disease is a fatal condition that destroys the brain and spinal cord. People who develop VCJD cannot spread the disease to other people through casual contact or through the air by a cough or a sneeze etc. About 10 to 15 percent of cases are inherited as a result of gene mutation and can also be transmitted through blood transfusions