Symptoms, Causes and Treatments for vCJD

Written by Michael W. Smith, MD

• Mad cow disease has hit the U.S. and questions about this mysterious disease abound. Here’s what you need to know about mad cow disease.
• What Is Mad Cow Disease?
• Does Cooking Food Kill the Prion That Causes Mad Cow Disease?
• Does Mad Cow Disease Affect Humans?
• What Are the Symptoms of vCJD?
• Is it Possible to Get vCJD From Eating Food Purchased in the U.S.?
• Can You Get vCJD From Drinking Milk From an Infected Cow?
• What About Other Products Made From Cow By-Products?
• What Is the Current Risk of vCJD to Americans Traveling Abroad?
• How Long Have Health Officials Been Concerned About Mad Cow Disease?
• What Other Countries Have Reported Cases of Mad Cow Disease?
• More

Mad cow disease, or bovine spongiform encephalopathy (BSE), is a transmissible, slowly progressive, degenerative, and fatal disease affecting the central nervous system of adult cattle. The U.S. Department of Agriculture (USDA) has tested hundreds of thousands of cattle for BSE.

Researchers believe that the infectious agent that causes mad cow disease is an abnormal version of a protein normally found on cell surfaces, called a prion. For reasons still unknown, this protein becomes altered and destroys nervous system tissue — the brain and spinal cord.

Common methods to eliminate disease-causing organisms in food, like heat, do not affect prions. Also, prions only seem to live in nervous system tissue.

A human version of mad cow disease called variant Creutzfeldt-Jakob disease (vCJD) is believed to be caused by eating beef products contaminated with central nervous system tissue, such as brain and spinal cord, from cattle infected with mad cow disease. For this reason, the USDA requires that all brain and spinal cord materials be removed from high-risk cattle — older cattle, animals that are unable to walk, and any animal that shows any signs of a neurological problem. These cow products do not enter the U.S. food supply. The USDA believes this practice effectively safeguards U.S. public health from vCJD.

According to the CDC, four deaths from vCJD have been identified in the U.S. However, it’s believed those cases were caused by consumption of meat outside the U.S.

It is important to clarify the differences between variant CJD and another form of the disease, referred to as classic or sporadic CJD. Classic CJD has no known cause and occurs each year at a rate of one to two cases per 1 million people throughout the world, including in the U.S. and countries where mad cow disease has never occurred. It is not linked to eating nerve tissue from mad cow disease-affected cattle — both vegetarians and meat eaters have died from classic CJD. CJD most commonly affects people over 65 and is usually fatal within six months from onset of symptoms.

The disease can affect all age groups and is very hard to diagnose until it has nearly run its course. In the early stages of vCJD, people have symptoms related to the nervous system, like depression and loss of coordination. Later in the illness, dementia develops. But only in advanced stages of the disease can brain abnormalities be detected by MRI (magnetic resonance imaging). vCJD is fatal, usually within 13 months of the onset of symptoms.

It is extremely unlikely that this would happen. To prevent mad cow disease from entering the country, since 1989 the federal government has prohibited the importation of certain types of live animals from countries where mad cow disease is known to exist. This ban includes meat products used in human, animal, and pet foods. In addition, prohibiting high-risk animals from entering the food supply and the removal of central nervous system tissue from the food supply help ensure that BSE is not a risk to consumers.

Milk and milk products are not believed to pose any risk for transmitting mad cow disease to humans. Experiments have shown that milk from mad cow-infected cows has not caused infections.

The FDA stops the importation of cosmetic and dietary supplement ingredients containing bovine materials from animals originating in the 33 countries where mad cow disease has been found or from animals at risk of being infected.

According to the CDC, the current risk of acquiring vCJD from any specific country appears to be extremely small. But that cannot be precisely determined because cattle products from one country might be distributed and consumed in others.

Mad cow disease has been of great concern since 1986, when it was first reported among cattle in the U.K. At its peak in January 1993, almost 1,000 new cases per week were identified. Concern about this disease grew significantly in 1996 when an association between mad cow disease and vCJD in humans was discovered.

The disease also has been confirmed in cattle born in Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Italy, Ireland, Israel, Japan, Liechtenstein, Luxembourg, the Netherlands, Poland, Portugal, Slovakia, Slovenia, Spain, Switzerland, and the U. K.

Canada has also been added to the list of countries from which imports are restricted, although that ban has been lifted recently. Importation of minimal-risk meat products is now allowed from Canada.

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Symptoms, Causes and Treatments for vCJD

Written by Michael W. Smith, MD

• Mad cow disease has hit the U.S. and questions about this mysterious disease abound. Here’s what you need to know about mad cow disease.
• What Is Mad Cow Disease?
• Does Cooking Food Kill the Prion That Causes Mad Cow Disease?
• Does Mad Cow Disease Affect Humans?
• What Are the Symptoms of vCJD?
• Is it Possible to Get vCJD From Eating Food Purchased in the U. S.?
• Can You Get vCJD From Drinking Milk From an Infected Cow?
• What About Other Products Made From Cow By-Products?
• What Is the Current Risk of vCJD to Americans Traveling Abroad?
• How Long Have Health Officials Been Concerned About Mad Cow Disease?
• What Other Countries Have Reported Cases of Mad Cow Disease?
• More

Mad cow disease, or bovine spongiform encephalopathy (BSE), is a transmissible, slowly progressive, degenerative, and fatal disease affecting the central nervous system of adult cattle. The U.S. Department of Agriculture (USDA) has tested hundreds of thousands of cattle for BSE.

Researchers believe that the infectious agent that causes mad cow disease is an abnormal version of a protein normally found on cell surfaces, called a prion. For reasons still unknown, this protein becomes altered and destroys nervous system tissue — the brain and spinal cord.

Common methods to eliminate disease-causing organisms in food, like heat, do not affect prions. Also, prions only seem to live in nervous system tissue.

A human version of mad cow disease called variant Creutzfeldt-Jakob disease (vCJD) is believed to be caused by eating beef products contaminated with central nervous system tissue, such as brain and spinal cord, from cattle infected with mad cow disease. For this reason, the USDA requires that all brain and spinal cord materials be removed from high-risk cattle — older cattle, animals that are unable to walk, and any animal that shows any signs of a neurological problem. These cow products do not enter the U.S. food supply. The USDA believes this practice effectively safeguards U.S. public health from vCJD.

According to the CDC, four deaths from vCJD have been identified in the U.S. However, it’s believed those cases were caused by consumption of meat outside the U.S.

It is important to clarify the differences between variant CJD and another form of the disease, referred to as classic or sporadic CJD. Classic CJD has no known cause and occurs each year at a rate of one to two cases per 1 million people throughout the world, including in the U. S. and countries where mad cow disease has never occurred. It is not linked to eating nerve tissue from mad cow disease-affected cattle — both vegetarians and meat eaters have died from classic CJD. CJD most commonly affects people over 65 and is usually fatal within six months from onset of symptoms.

The disease can affect all age groups and is very hard to diagnose until it has nearly run its course. In the early stages of vCJD, people have symptoms related to the nervous system, like depression and loss of coordination. Later in the illness, dementia develops. But only in advanced stages of the disease can brain abnormalities be detected by MRI (magnetic resonance imaging). vCJD is fatal, usually within 13 months of the onset of symptoms.

It is extremely unlikely that this would happen. To prevent mad cow disease from entering the country, since 1989 the federal government has prohibited the importation of certain types of live animals from countries where mad cow disease is known to exist. This ban includes meat products used in human, animal, and pet foods. In addition, prohibiting high-risk animals from entering the food supply and the removal of central nervous system tissue from the food supply help ensure that BSE is not a risk to consumers.

Milk and milk products are not believed to pose any risk for transmitting mad cow disease to humans. Experiments have shown that milk from mad cow-infected cows has not caused infections.

The FDA stops the importation of cosmetic and dietary supplement ingredients containing bovine materials from animals originating in the 33 countries where mad cow disease has been found or from animals at risk of being infected.

According to the CDC, the current risk of acquiring vCJD from any specific country appears to be extremely small. But that cannot be precisely determined because cattle products from one country might be distributed and consumed in others.

Mad cow disease has been of great concern since 1986, when it was first reported among cattle in the U. K. At its peak in January 1993, almost 1,000 new cases per week were identified. Concern about this disease grew significantly in 1996 when an association between mad cow disease and vCJD in humans was discovered.

The disease also has been confirmed in cattle born in Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Italy, Ireland, Israel, Japan, Liechtenstein, Luxembourg, the Netherlands, Poland, Portugal, Slovakia, Slovenia, Spain, Switzerland, and the U.K.

Canada has also been added to the list of countries from which imports are restricted, although that ban has been lifted recently. Importation of minimal-risk meat products is now allowed from Canada.

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Mad cow disease

Spongiform encephalopathy (Bovine Spongiform Encephalopathy, BSE) or goats, chronic wasting disease in deer (zombie deer), Creutzfeldt-Jakob disease in humans. Like all prion diseases, mad cow disease has a dangerously long incubation period and can manifest itself 5-8 years after infection.
Mad cow disease was first diagnosed in the UK at 1985, and it took some more time to determine the disease. The infection of such a large number of livestock occurred due to the use of feed containing meat and bone meal with prion proteins.

The disease causes very serious economic damage. In the UK, about 4 million cattle were destroyed; dealt a serious economic and reputational blow to agriculture.
Thanks to the OIE’s stringent measures to control the use of feed of animal origin, the movement of animals and regular post-mortem examinations, mad cow disease has virtually disappeared. Sometimes isolated cases are recorded.

Spongiform encephalopathy prions have been shown to be transmitted to humans, causing Creutzfeldt-Jakob disease.

• Animal species: Cattle
• Disease category: Disease of the nervous system
• Zooanthroponosis: Yes
• 9000 4 Contagious: Yes
• Treated: No
• Natural focal: No
• Age groups: All

🔴 Species affected

Cattle. Cows get sick, bulls get infected less often.

🔴 Distribution

The disease is registered in almost all European countries, Asia, the Middle East, South and North America, Japan and Australia.

🔴 Etiology

Infection occurs through feed of animal origin: meat and bone meal, milk powder, etc. Products and preparations containing tissues of the spinal cord and brain are especially dangerous. There are no data on animal-to-animal transmission and very little data on infections transmitted from mother to fetus.
The disease is slow-moving and the diseased animal is often slaughtered before clinical signs appear. According to the OIE, after infection, clinical signs appear, depending on the age and immunity of the animal, in the range from two to eight years.
Prion is resistant to heat and drying. This means that meat and milk from sick animals cannot be used as food or fed to other animals. Cases of infection of large felines in zoos have been reported when feeding meat from cows with mad cow disease.
Prions persist in the environment for a long time. There is evidence that prions live in water for about a year, and in soil for about three years. Even after passing through the digestive system of birds and mammals, prions retain their ability to remain infectious.
In diseased animals, 100% death.

🔴 Pathogenesis

The origin, course and spread of the disease still require scientific research.
Mad cow disease is caused by a special type of protein called a prion. This protein has a self-sustaining altered form. When a defective protein enters the body, it causes the surrounding normal proteins to assume the same shape. This process is in the nature of a chain reaction and leads to the formation of large or cluster-like vacuoles in neuronal cells, and the brain tissue acquires a spongy structure. These changes are irreversible.

The uniqueness of the prion is that it does not have hereditary information in its structure and, if the configuration of the protein polypeptide chain matches, is able to overcome the species barrier. This is confirmed by an experiment on infecting mice with sheep prions (scrapie). It is assumed that the epidemic in the UK in 1985-1986 began with the purchase of a large batch of meat and bone meal, the raw material for which was infected scrapie sheep.

📌There are two strains:

1. Classic mad cow disease. Transmitted through prion-contaminated food. It is assumed that young animals get sick, and then the disease slowly develops with irreversible consequences.
2. Atypical mad cow disease . Occurs spontaneously, and it is not yet known how infection occurs. Only old animals get sick. Infection through food in this case is excluded. It is assumed that in an old animal, the body ceases to maintain the constancy of the internal environment and proteins begin to fold into the form of a prion on their own.

Mad cow disease is listed by the OIE and all countries are required to report cases of the disease. Quarantine restrictions are imposed on the country: the export of livestock, meat, dairy and other products with additives of animal origin is prohibited.
Mad cow disease must be differentiated from encephalitis, rabies, tetanus, poisoning.

🔴 Clinical signs

• Wasting;
• Loss of productivity;
• Violation of coordination of movements;
• Hypersensitivity to sudden sounds and touch;
• Aggressive behavior;
• Tremor;
• Motor retardation.

🔴 Autopsy picture

No serious changes in the body are found at autopsy, except in cases of severe exhaustion.
Spongy lesions limited to the brain and spinal cord.
Fluid-filled cavities are clearly visible on a histological section of the brain tissue. Cells show single or multiple vacuoles.

🔴 Diagnosis

Diagnosis is based on clinical signs.
Currently, there is no test that can reliably confirm the presence of mad cow disease in vivo.
Diagnosis is postmortem based on histological examination of the medulla oblongata.
The diagnosis is confirmed by immunochemical or immunohistochemical detection of a specific prion protein in the medulla oblongata tissue.

🔴 Treatment

Not developed.

🔴 Prevention

No vaccine.

• Strict registration of cattle, its identification and movement tracking.
• Timely detection and registration of disease outbreaks.
• Post-mortem examination of medulla oblongata tissues.
• Complete openness and transparency of information about mad cow disease for all interested parties.
• Prohibition of the use of feed or supplements of animal origin, such as meat and bone meal.
• Carcass cutting destroys special risk materials such as brain and spinal cord, eyes, skull, spine, tonsils, distal ileum.
• Import of cattle only from clean countries and regions.
• Destruction of all diseased animals or animals suspected of having mad cow disease.

Sources used in writing the material:

1. www.oie.int/…
2. I. S. SHKUNDINA, M. D. TER-AVANESYAN, FGU Russian Cardiological Research and Production Complex of Roszdrav, Moscow 2006

“Mad cow disease” detected in the USA – RBC

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In the US state of Washington, the first case of encephalopathy, or “mad cow disease” has been detected in the history of the country, AP reports.

As US Secretary of Agriculture Ann Winiman said at a press conference, preliminary results of the study confirmed the fact of the disease. According to her, the tissue sample was taken from a sick animal for research 9December. So far, only preliminary results have been obtained. To confirm them, the sample was sent by military aircraft to the laboratory of animal diseases in England. It is expected that the final results will be received within 3-5 days.

The USDA intends to hold daily briefings to keep the public informed of developments in the situation. According to E. Viniman,
she has already spoken to US Secretary of Homeland Security Tom Ridge about the latest developments. At the same time, E. Viniman pointed out that, judging by the information she had, the detection of “mad cow disease” had nothing to do with the terrorist threat.

However, the minister noted that “US food supplies” are still safe. According to E. Viniman, the diseased cow is not part of the livestock, the meat of which is intended for export.

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Meanwhile, a farm in the state of Washington where a case of “mad cow disease” has been identified has been quarantined. US President George W. Bush has already been informed about this.

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American analysts predict that now many countries will impose a ban on the import of American beef, which will result in significant financial losses for the US meat industry. In Canada, a single case of “mad cow disease” cost the country 3.3 billion Canadian dollars.

Indeed, Japan and South Korea have already banned the import of American beef and beef products. In these countries, in addition, trade in American meat products that have already entered the market will be terminated.

Note that Japan is the largest consumer of American beef.