What are the symptoms of mad cow disease in humans? How is the disease diagnosed and treated? Get the facts about this rare but deadly neurological disorder.

The Deadly Threat of Mad Cow Disease

Creutzfeldt-Jakob disease (CJD) made headlines in the year 2000 when an uptick of cases broke out in the United Kingdom. These cases were linked to food contaminated with bovine spongiform encephalopathy (BSE), a prion disease that causes variant CJD, otherwise known as “mad cow” disease. The public has good reason to be concerned about the transmission of BSE to humans, as variant CJD is a rapidly progressing, always fatal neurological disorder.

Rare but Deadly: The Prevalence of CJD

CJD is a very rare disease, affecting about one person in every one million per year worldwide. In the United States, there are approximately 350 cases per year. The Centers for Disease Control and Prevention (CDC) closely monitors the incidence of all types of CJD in the United States.

Different Causes, All Equally Fatal

There is no cure for CJD, which can occur in a person in one of three ways: about 10-15% of cases are inherited, most cases appear sporadically with no family history, and a small percentage of cases occur through infection by contact with infected brain tissue. CJD is not contagious in normal ways, such as sneezing or coughing, and there are no known cases of spouses or family members of an infected person contracting the disease.

Contaminated Beef: The Link to Variant CJD

Cases of variant CJD seem to be linked to eating contaminated beef products in Europe. The same disease, when it occurs in sheep, is called “scrapie.” It is believed that scrapie-infected sheep products were used in cattle feed, and that is how the cattle became infected. The cause of BSE, scrapie, and the Creutzfeldt-Jakob diseases is not a virus or bacteria, but a protein agent called a prion, which transforms normal proteins into infectious, deadly ones.

The Devastating Effects on the Brain

Since CJD affects the brain, the symptoms it produces are neurological. It may start out subtly with insomnia, depression, confusion, personality and behavioral changes, and problems with memory, coordination, and sight. As the disease progresses, the person rapidly develops dementia and involuntary, irregular jerking movements called myoclonus. In the final stage, the patient loses all mental and physical functions, lapses into a coma, and eventually dies, usually within one year.

Difficulties in Diagnosis

There is not yet a definitive medical test for diagnosing CJD, and confirmation of the disease can only be made after death through an autopsy. Since the disease is rare, some physicians might not even consider it as a diagnosis and might mistake the symptoms for other brain disorders like Alzheimer’s or Huntington disease. Scientists suggest that new, sophisticated laboratory testing will in the future be able to detect the prions in an infected person’s blood or tissues.

Early Symptoms and Progression

The most common early symptoms of CJD—memory loss and confusion—may resemble those of other dementias, such as Alzheimer’s disease. These symptoms are the first to occur in most people with CJD but eventually develop in all affected people. For others, the first symptom is loss of muscle coordination (ataxia). In people with variant CJD, the first symptoms tend to be psychiatric symptoms (such as anxiety or depression), rather than memory loss. Later symptoms are similar in both forms.

Whether symptoms develop gradually or abruptly, mental function continues to deteriorate, often causing such symptoms as neglect of personal hygiene, listlessness, and irritability. Some people tire easily and become sleepy, while others cannot fall asleep. Muscles usually begin to jerk involuntarily and quickly (called myoclonus) during the first 6 months after symptoms begin. Muscles may tremble, and people may become clumsy and uncoordinated. Walking becomes unsteady, resulting in staggering (similar to the walk of a person who is drunk). Movements may be slow, and impairment of muscle control may result in unusual postures, such as twisting of the trunk or limbs forward and sideways. Muscles may jerk.

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 generally affects people between the ages of 50 to 75 years, however, variant Creutzfeldt-Jakob disease has affected people at a younger age—even teenagers (the ages have ranged from 18 to 53 years old).

Diagnosing the Rare and Deadly Disease

There is not, as yet, a definitive medical test for diagnosing Creutzfeldt-Jakob disease, and confirmation of the disease can only be made after death through an autopsy. Since the disease is rare, some physicians might not even consider it as a diagnosis and might mistake the symptoms for other brain disorders like Alzheimer’s or Huntington disease. Scientists suggest that new, sophisticated laboratory testing will in the future be able to detect the prions in an infected person’s blood or tissues.

Deadly Mad Cow Disease in Humans

Creutzfeldt-Jakob disease made headlines in the year 2000 when an uptick of cases broke out in the United Kingdom. Those cases were linked to food contaminated with bovine spongiform encephalopathy (BSE), a prion disease that causes variant CJD, otherwise known as “mad cow” disease.

The public has good reason to be concerned about the transmission of BSE to humans. Variant Creutzfeldt-Jakob disease, like the other types of Creutzfeldt-Jakob disease, is a rapidly progressing, always fatal neurological disorder. But the disease is very rare: It affects about one person in every one million per year worldwide; in the United States there are about 350 cases per year. 

The Centers for Disease Control and Prevention (CDC) monitors the incidence in the United States of all types of Creutzfeldt-Jakob disease.

istetiana / Getty Images

Different Types of Disease, Always Fatal

There is no cure for Creutzfeldt-Jakob disease, which can occur in a person in one of three ways:

• About 10% to 15% of cases in the United States are inherited, resulting from a gene mutation.
• Most cases seem to appear sporadically, in someone who has no family history of the disease.
• A small percentage of cases occur through infection, by contact with infected brain tissue. There are documented cases that occurred as an unintended consequence of a medical procedure.

Creutzfeldt-Jakob disease is not contagious in normal ways, like sneezing or coughing–there are no known cases of spouses or family members of an infected person contracting the disease.

Contaminated Beef Products 

Cases of variant Creutzfeldt-Jakob disease seems to be linked to eating contaminated beef products in Europe. The same disease, when it occurs in sheep, is called “scrapie.” It is believed that scrapie-infected sheep products were used in cattle feed, and that is how the cattle became infected.

Scientists have found that what causes BSE, scrapie, and the Creutzfeldt-Jakob diseases is not a virus or bacteria as in other diseases, but a protein agent called a prion. The prion transforms normal proteins into infectious, deadly ones.

Effects on the Brain

Since Creutzfeldt-Jakob disease affects the brain, the symptoms it produces are neurological. It may start out subtly with insomnia, depression, confusion, personality and behavioral changes, and problems with memory, coordination, and sight. As it progresses, 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 generally affects people between the ages of 50 to 75 years, however, variant Creutzfeldt-Jakob disease has affected people at a younger age–even teenagers (the ages have ranged from 18 to 53 years old).

Difficult to Diagnose

There is not, as yet, a definitive medical test for diagnosing Creutzfeldt-Jakob disease, and confirmation of the disease can only be made after death through an autopsy. Since the disease is rare, some physicians might not even consider it as a diagnosis and might mistake the symptoms for other brain disorders like Alzheimer’s or Huntington disease. Scientists suggest that new, sophisticated laboratory testing will in the future be able to detect the prions in an infected person’s blood or tissues.

Creutzfeldt-Jakob Disease (CJD) – Brain, Spinal Cord, and Nerve Disorders

The most common early symptoms of Creutzfeldt-Jakob disease—memory loss and confusion—may resemble those of other dementias, such as Alzheimer disease. These symptoms are the first to occur in most people with CJD but eventually develop in all affected people. For others, the first symptom is loss of muscle coordination (ataxia). In people with vCJD, the first symptoms tend to be psychiatric symptoms (such as anxiety or depression), rather than memory loss. Later symptoms are similar in both forms.

Whether symptoms develop gradually or abruptly, mental function continues to deteriorate, often causing such symptoms as neglect of personal hygiene, listlessness, and irritability. Some people tire easily and become sleepy. Others cannot fall asleep.

Muscles usually begin to jerk involuntarily and quickly (called myoclonus) during the first 6 months after symptoms begin. Muscles may tremble, and people may become clumsy and uncoordinated. Walking becomes unsteady, resulting in staggering (similar to the walk of a person who is drunk). Movements may be slow. Impairment of muscle control may result in unusual postures, such as twisting of the trunk or limbs forward and sideways. Muscles may jerk when stretched. Some people have hallucinations and seizures.

People may startle easily, and the resulting responses, such as jumping when a loud noise is heard, are exaggerated. Startling may trigger muscle jerking.

The muscles that control breathing and coughing are usually impaired, increasing the risk of pneumonia.

Vision may become blurry or dim.

The symptoms worsen, usually much more rapidly than in Alzheimer disease, resulting in severe dementia.

Most people with CJD die within 6 to 12 months after symptoms appear. About 10 to 20% of people survive for 2 years or more. People with vCJD usually survive for about 18 months. Often, the cause of death is pneumonia.

People may have no symptoms for 10 to 20 years after they acquire vCJD.

Bovine Spongiform Encephalopathy – Causes, Symptoms, Treatment, Diagnosis

The Facts

Bovine spongiform encephalopathy (BSE), commonly known as “mad cow disease,” is a fatal disease that strikes the nervous system of cattle.

BSE is part of a group of diseases called prion diseases that occur in both animals and humans.  The main animal forms are chronic wasting disease in deer, scrapie in sheep, and mad cow disease. In humans, there are three different prion diseases: Creutzfeldt-Jacob disease (CJD), also named sporadic CJD (sCJD), Gerstmann-Straussler-Scheinker disease, and fatal familial insomnia. In 1996, another form of CJD was identified; it has since been named “variant CJD” (vCJD). This variant form of CJD has been linked to the consumption of meat products infected with BSE.

Currently, no vaccine or treatment exists to treat BSE, and affected animals display a variety of neurological symptoms before they die (think of television reports showing cows having trouble standing up).

An animal with outward symptoms of BSE may survive for 2 weeks to 6 months, though it may have carried the disease for up to 8 years. BSE has an incubation period (the time between infection and development of symptoms) ranging from 30 months to 8 years, which is a long time for a disease to remain undetected.

Causes

Scientists believe that BSE is most often spread through the practice of feeding cattle various meats (rendered material) from slaughtered animals such as sheep, goats, and other cattle.

During this process, an abnormal protein that is linked to BSE can spread from a slaughtered diseased animal to a healthy one. This abnormal protein, called a prion, can withstand high temperatures and does not get destroyed during the rendering procedure. Since the incubation period for BSE is so long, it is possible for an infected animal to enter the food chain before the symptoms appear.

Proteins are long molecules that are folded up into particular shapes. A prion is folded differently from a normal protein, and it can cause normal proteins to change and fold abnormally. When this happens, the proteins (normally found in liquid form in cells) begin to solidify.

The cells most often infected are the brain cells. The resulting solidification of the proteins causes the infected brain tissues to look like a sponge with several tiny holes, hence the name “spongiform encephalopathy.”

Symptoms and Complications

Because BSE damages the brain tissue, it has a variety of symptoms ranging from behavioural changes to coordination problems. Cows with BSE may show nervousness or aggressive behaviour, difficulty with coordination, trouble standing up, decreased milk production, and weight loss. The disease is fatal, with death usually occurring 2 weeks to 6 months after symptoms start.

sCJD usually occrs in older patients with an average age of 67, but it has been reported in teenagers and people in their 90s. It is fatal after only a few months. vCJD usually occurs in younger patients and lasts about one and a half years.

Making the Diagnosis

Live animals cannot be tested for the disease. The only way to confirm the presence of BSE is by checking the brain tissue of an animal after it dies. Upon examination, the brain is found to be full of small holes, like a sponge.

In humans, a genetic test exists to determine if a person might be susceptible to vCJD, but again, the only way to confirm the diagnosis is through a sample of brain tissue obtained through a biopsy or autopsy.

Treatment and Prevention

There is no cure, treatment, or vaccine for BSE, CJD, or vCJD.

The best way to prevent the disease is to avoid feeding cattle rendered material from slaughtered animals, and to isolate and destroy all infected animals. Most countries have developed policies for monitoring BSE in their cattle herds and procedures for dealing promptly and thoroughly with BSE cases when they do arise.

Canada is continuing to work to prevent and control BSE:

• Health Canada works closely with the Canadian Food Inspection Agency (CFIA) as part of the agency’s National Response Team.
• The CFIA has taken various precautions to prevent the introduction and spread of BSE, including creating a surveillance program in which the brains of cattle are tested for the disease.
• The CFIA has mandated that all suspected BSE cases be reported to a federal veterinarian. The CFIA has also created a Canadian Cattle Identification Program for cattle and bison, making it possible to trace individual animal movements from the herd of origin to the time of slaughter.
• In 1997, Canada banned the feeding of rendered protein products from ruminant animals (cattle, sheep, goats, bison, elk, or deer) to other ruminants.
• In 2007, Canada implemented an enhanced BSE-related feed ban. This regulation extends the original feeding ban to all animal feeds, pet food, and fertilizer products.
• A permit issued by the CFIA is now required for those needing to handle, transport, or dispose of cattle carcasses and certain cattle tissues.
• More detailed policies regarding the prevention and control of BSE are available on the Health Canada website.

All material copyright MediResource Inc. 1996 – 2021. Terms and conditions of use. The contents herein are for informational purposes only. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Source: www.medbroadcast.com/condition/getcondition/Bovine-Spongiform-Encephalopathy

Bovine spongiform encephalopathy (BSE) | MPI

Find out about bovine spongiform encephalopathy (BSE), the work MPI does to minimise the risk to New Zealand and how you can help.

Mad cow disease

Bovine spongiform encephalopathy (BSE) is a type of transmissible spongiform encephalopathy that exclusively affects cattle.

BSE causes mania-symptoms in cows – trouble controlling legs, erratic behaviour and increased aggression. Because of this, it’s become commonly known as mad cow disease.

BSE rose to international awareness after a severe outbreak began in the United Kingdom in 1986. By the end of 2001, around 180,000 cases of the disease had been declared. At the height of the epidemic, nearly 1,000 new cases were being reported every week.

BSE was first confirmed in North America in 2003. Reported cases since its discovery have been much lower than in the UK.

The first case of BSE to occur in France was declared in early 2016.

BSE in humans

In 1996, BSE was confirmed in humans as a disease called variant Creutzfeldt-Jakob Disease (vCJD). vCJD spreads when meat from diseased cattle is consumed.

There are no known cases of vCJD in New Zealand.

Preparing to respond

An outbreak of BSE could have a severe impact on New Zealand’s economy. Exports of cattle meat, semen, embryos, biopharmaceuticals and livestock could all be affected.

Many countries, including New Zealand, have import bans in place for meat and meat-products that could spread BSE. Unfortunately, BSE can also be caused by spontaneous genetic change (an abnormal change in DNA that is not passed from parents to offspring). The risk to New Zealand is incredibly low but we cannot guarantee 100% safety – early detection is one of our best defences.

MPI runs an early detection programme for TSEs. Farmers and vets can receive financial compensation for participating in the programme.

Find out more about our TSE surveillance programme

You can help

BSE can incubate for up to 8 years before an infected animal shows symptoms. It spread very quickly in the United Kingdom – most likely due to cows being fed mix containing the remains of animals no one knew were infected.

To prevent this sort of accidental spread, MPI has ruminant feeding regulations in place in New Zealand.

If you have ruminant animals – including cows, goats, sheep and deer – you must not feed them any food containing meat, organs or bones from other ruminants.

Find out more about ruminant feeding controls in New Zealand

Who to contact

• To report a pest or disease, call 0800 80 99 66.
• If you have questions about the information on this page, email [email protected]

Mad Cow Disease – Tufts Medical Center Community Care

What is mad cow disease?

Mad cow disease is a disease found in cows that can spread to people. It affects the brain and spinal cord, causing a breakdown of the nervous system. It is also called bovine spongiform encephalopathy (BSE). It rarely occurs in humans, but when it does, it is called variant Creutzfeldt-Jakob disease (CJD). It leads to death in 6 months to 5 years.

What is the cause?

The disease is caused by an abnormal version of a kind of protein called a prion. It is spread among cows when they are fed ground meat and bones from other cows. It can spread to people when they eat beef that contains the abnormal protein. In some cases CJD appears to have been spread by blood transfusions from infected donors.

What are the symptoms?

Symptoms may not develop for several years after infection with the abnormal protein. When symptoms develop, they include:

• Worsening memory and confusion
• Muscle spasms or lack of muscle control
• Trouble sleeping
• Unsteadiness when you walk
• Depression or anxiety
• Feeling very irritable or angry
• Seizures

How is it diagnosed?

Your healthcare provider will ask about your symptoms and medical history and examine you. Your provider will ask about your eating patterns. CJD is difficult to diagnose. Tests may include:

• Blood tests
• MRI, which uses a strong magnetic field and radio waves to show detailed pictures of the brain
• PET scan, which is a series of detailed pictures that are taken after your healthcare provider injects a small amount of radioactive material into your blood.
• EEG, which measures and records the electrical activity in the brain
• A spinal tap to look at the levels of specific proteins
• A brain biopsy, which is the removal of a tiny sample of tissue for testing

How is it treated?

A cure has not yet been found for mad cow disease. Your healthcare provider may refer you to a specialist for treatment.

Medicines may be prescribed to slow the disease. Other medicines may be prescribed to treat symptoms, such as depression or seizures.

How can I take care of myself?

Follow your health provider’s instructions for care. Take the medicines prescribed for you to lessen symptoms.

How can I help prevent mad cow disease?

The risk of getting mad cow disease from beef is very low, but you can lower your risk if you:

• Eat chicken or fish instead of beef.
• Avoid beef products that could contain spinal cord or brain tissue. This includes ground beef, sausage, and hot dogs.
• If you travel to a country where mad cow disease has been detected, avoid beef. These countries include the United Kingdom, France, Spain, and others.

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Creutzfeldt-Jakob disease (CJD) factsheet – Fact sheets

What is Creutzfeldt-Jakob disease?

Creutzfeldt-Jakob disease, also known as CJD, is a rare degenerative disease of the brain that is fatal. It is one of a group of diseases known as the transmissible spongiform encephalopathies.

In CJD, the structure of a normal brain protein changes slightly forming prions. The build up of prions damages brain cells and causes the neurological symptoms of CJD. Unlike bacteria or viruses, prions resist normal methods of heat and chemical sterilization and, very rarely, prions can be transmitted to others.

There are two different types of Creutzfeldt-Jakob disease:

• Classical CJD occurs in Australia and about one in one million people per year develops the disease. There are three types of classical CJD. About 90% of classical CJD cases occur by chance (sporadic CJD) and 10% of cases are hereditary (familial or inherited CJD). The disease has very rarely been transferred between patients following medical procedures such as brain surgery or the use of dura mater grafts or contaminated human pituitary hormones (iatrogenic CJD).
• Variant CJD, is a disease that emerged in the UK in the 1990s. Variant CJD is linked to the consumption of meat products from cattle infected with bovine spongiform encephalopathy (BSE, or “mad cow disease”). Variant CJD is a separate disease to classical CJD, although some of the symptoms are similar. No cases of variant CJD have been identified in Australia to date. Australian cattle remain free of BSE.

What are the symptoms?

People with classical CJD have progressive neurological symptoms that may include behavioural changes, blindness, weakness, loss of balance and incoordination, difficulty walking or speaking and muscle spasm. Confusion in the early stages usually progresses to dementia. The disease is fatal, usually weeks to months after onset of symptoms.

People with variant CJD tend to be younger, have a slower rate of deterioration and tend to have more psychiatric symptoms or personality changes than patients with classical CJD.

How is it spread?

Most cases of CJD occur because of mutations with a person’s brain and are not spread from other people.

Some medical procedures carried out on people with CJD have very rarely resulted in the disease being transmitted to other people. For example:

• Human pituitary hormones derived from people who died with CJD resulted in transmission in the past and five of these cases occurred in Australia. Therapeutic pituitary hormones are no longer obtained from this source and no high-risk treatments occurred in Australia after 1985.
• Neurosurgical instruments contaminated following an operation on someone with CJD has resulted in five cases worldwide, and none since the 1970s.
• Dura mater grafts taken from donors who had CJD and used to patch holes in the lining outside the brain; corneal grafts taken from donors who had CJD and used in others have resulted in three cases of transmission worldwide and none in Australia.

Screening procedures and improvements to standards of infection control have made transmission of CJD in the modern health care setting extremely unlikely.

Variant CJD may be spread more easily from person-to-person than classical CJD. In contrast to classical CJD, variant CJD may also be transmitted to humans after eating contaminated meat and meat products from cattle with BSE, via transfusion of blood and blood products, and some other operations if the instruments are not processed properly.

Who is at risk?

Each year, about one in every million Australians develops sporadic CJD and most have no risk factors for the disease. The average age of onset is about 65 years.

Familial or inherited CJD includes familial CJD, Gerstmann-Sträussler-Scheinker (GSS) syndrome and fatal familial insomnia (FFI) and is carried from one generation of a family to the next by abnormal genes.

The risk of transmission in the health care setting is extremely low.

How is it prevented?

Special infection control precautions are used for patients thought to at risk of CJD. Products or instruments potentially contaminated with prions are removed from use.

In Australia, there is a very low risk of variant CJD; to safeguard the blood supply, people are excluded from donating blood if they have lived in the United Kingdom for more than 6 months between 1980 and 1996.

How is it diagnosed?

A definite diagnosis of Creutzfeldt-Jakob disease can only be made by special tests of the brain tissue; this almost always occurs after the patient has died. Other specialized tests for people with typical signs and symptoms can help to make a diagnosis, but do not confirm the diagnosis.

To confirm the diagnosis after death an autopsy is usually recommended. The RPA Hospital’s Department of Neuropathology provides specialised CJD diagnostic services in NSW.

There is no screening test for CJD.

How is it treated?

There is no specific treatment for Creutzfeldt-Jakob disease.

What is the public health response?

Hospitals and laboratories are required to notify patients with Creutzfeldt-Jakob disease to the local public health unit (under the NSW Public Health Act 2010). The Australian National Creutzfeldt-Jakob Disease Registry coordinates surveillance and testing for CJD cases in Australia. The Registry works with NSW Health and local public health units to identify if cases have had high-risk procedures and to provide specialist advice for clinicians.

Further information

CJD Support Group Network Australia

Further information for clinicians on testing for CJD, see the RPA Hospital Department of Neuropathology CJD testing information.

Australian National Creutzfeldt-Jakob Disease Registry.

For further information please call your local public health unit on 1300 066 055.

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Lab-made prions trigger mad cow symptoms

Result shows protein alone can act as infectious agent in disease.

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Synthetic prion proteins can infect mice.
Credit: © Science

Researchers have created a synthetic protein that makes mice display symptoms similar to those of mad cow disease.

The protein, called a prion, helps to resolve a long-standing debate on the cause of certain degenerative brain conditions, such as Creutzfeldt-Jakob disease (CJD) in humans and bovine spongiform encephalopathy (BSE) in cattle. Being able to manufacture the rogue protein in the lab may also aid the development of new therapies and speedy diagnostic tests.

Sporadic CJD, which accounts for 85% of prion diseases in humans, is thought to develop spontaneously. Researchers believe that healthy brain prions somehow become twisted out of shape and go on to trigger the production of more misshapen proteins. As the brain degenerates, patients lose the power of speech and movement. As there is no effective treatment, the disease is invariably fatal.

But there is controversy over whether a protein alone can trigger the disease. Many researchers believe that the infectious agent must also contain genetic material, such as DNA or RNA, in order to instruct the healthy proteins to turn bad.

To settle the point, Giuseppe Legname from the University of California, San Francisco and colleagues set out to make a synthetic prion protein, which they knew could not possibly contain DNA or RNA, to see whether it could trigger a BSE-like illness all by itself.

Creating the rogue prions from scratch was no mean feat. The researchers used bacteria to generate healthy-looking prion proteins and purified them. They shook these proteins until they changed their shape and resembled the twisted, unhealthy prions seen in diseased brains. Then the researchers injected the molecules into the brains of mice.

The mice developed BSE-like symptoms one to two years later, the team report in Science¹. They became weak and shaky, and post-mortem analysis revealed that their brains were full of holes and rogue prion proteins.

Critically, when the mouse brains were ground up and injected into healthy rodents, they too became ill. This is the acid test for any prion disease, says Legname.

“The data show that infectious prions can be formed de novo from only protein,” says prion researcher Surachai Supattapone from Dartmouth Medical School in Hanover, New Hampshire. The result should help to convince the sceptics who demanded proof from a chemical experiment that prions alone were sufficient to trigger the disease.

“The finding represents a renaissance in prion biology,” says Nobel laureate Stanley Prusiner, also from the University of California, San Francisco, who contributed to the research. Prusiner coined the term ‘prion’ and was the first to postulate the ‘protein-only’ hypothesis about infection. “For the first time, we can create prions in a test tube. We now have a tool for exploring the mechanism by which a protein can spontaneously fold into a shape that causes disease.”

The discovery could speed the development of new drugs and diagnostic tests. At the moment, for example, it is only possible to confirm that a patient had the disease after he or she has died.

The research could also boost our understanding of other degenerative brain disorders, such as Alzheimer’s and Parkinson’s disease. In Alzheimer’s disease, it may be that a protein called amyloid beta becomes misfolded and begins to clog up the brain. Mechanisms could be at work that are similar to those involved in creating rogue prions, says Legname.

About this article

Cite this article

Pilcher, H. Lab-made prions trigger mad cow symptoms.
Nature (2004). https://doi.org/10.1038/news040726-11

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Further reading

• Reform of land use urged as floodwaters rise across Asia

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  (2004)

90,000 Mad cow disease as a factor in the development of dementia in humans

In the midst of the coronavirus pandemic, Europeans will scold the Chinese more than once or twice: they say, if they did not eat any exotic, then a dangerous virus would not have jumped to us from bats.And then they will say: we Europeans are not like that. The British could claim the right to be considered the highest civilization in the world, if not for one thing. Do you know why the citizens of Foggy Albion who were born and lived in the UK before 1996 cannot donate blood in Europe?

As you know, Britain is the birthplace of capitalism. At first, the inhabitants of the kingdom began to build steam engines, then they began to weave clothes with machines. The speed of production has increased, the cost of the product has dropped. In the same spirit, the remnants of agriculture in the second half of the twentieth century were transferred to an industrial basis: maximum income, minimum unproductive waste.

These included the bones of cattle. They guessed to clean off the remnants of meat and extract the bone marrow from them. All this to grind and sell as “mechanically deboned meat”. Dry the bones themselves and grind them into bone meal, which was fed to the same cows, and also added to pet food.

In the same mines, from which the first, while stationary steam engines pumped out water, canaries were used to determine methane – a gas without odor and color.The canaries were the first to die, allowing the miners to escape. At the end of the 20th century, cats began to play the role of canaries. And first one cat, then the second died from an incomprehensible disease – at first they walked with braided legs, whirled in place and finally died.

A similar disease of the nervous system – sheep pruritus (when the sheep began to comb their sides until they bleed) – has been known in these paired mammals since the middle of the 18th century, but in the 1990s it was first discovered in cats. Since it was known that sheep pruritus was not transmitted to people, the UK Department of Agriculture recommended not to pay attention to it, and British beef was considered completely safe.

Although by the end of the 1990s Margaret Thatcher was no longer prime minister, in our story we cannot do without mentioning her name. The fact is that after the Second World War, the School Meals Act was passed in Britain, which stated that school meals should contain 50% of the calories children need. In the 70s, it was already 30%, and then Thatcher completely removed this minimum. During her reign, the state allocated less and less money for school meals (free for the poorest children).And now we already know where the bone meal of sick cows went and who regularly ate “mechanically deboned meat” – children.

The first cases of “mad cow disease” in humans were recorded in 1996 [1]. Symptoms included depression, anxiety, and hallucinations. Symptoms rapidly progressed to problems with coordination of movements and speech. Then came dementia, seizures and death. On average, the illness lasted 14 months, the average age of the cases was 28 years.

Note that a similar disease in humans – Creutzfeldt-Jakob disease – has been observed before.It is known to affect people over the age of 50 and is genetic. Another similar disease, kuru, was found in the natives of New Guinea, who had a custom of eating the brains of deceased relatives. So, no one denied the spontaneous nature of Creutzfeldt-Jakob disease, but what is the mechanism of its transmission?

The researcher kuru Stanley B. Prusiner (American professor of neurology and biochemistry, Nobel Prize winner 1997) suggested that the disease is transmitted without the participation of nucleic acids, only through protein.They did not believe him for a long time, because Francis Crick’s “central dogma of molecular biology” said that information can be transmitted to proteins only from nucleic acids (DNA and RNA). In this case, after years of debate, “dogma” has been modified into the formula “protein → protein”.

Sheep pruritus, “mad cow disease” and kuru are related to prion diseases (recall that “a prion is a protein with an abnormal tertiary structure, capable of catalyzing the conformational transformation of a homologous normal cellular protein into a similar one”).In these cases, one protein, the PrPSc nervous system receptor, changes from its normal, soluble form to an irregular (prion) that folds into long filaments.

Filaments are not capable of performing the function of a protein, but they lead to the development of disease symptoms. Moreover, pieces are torn off the threads that can convert normal protein into abnormal one. Mad cow disease, which crossed the species barrier, showed that prion infestation is possible.

As usual, after the first cases of the disease appeared, its development was projected into infinity, but since 2005 there has been a clear trend towards a fall in the number of cases, of which there were never too many – dozens.

Since then, Britain, taught by bitter experience, has abandoned the use of bone meal and “mechanically deboned meat”. It would seem that you can sleep peacefully. But there are still three problems left: a small one, a bigger one, and a very big one.

The little one is that at the critical point of the PrP protein there are two variants of the amino acid – valine and methionine. All patients with mad cow disease had a valine / methionine combination. The natives have a different combination of amino acids, and it took them 50 years to develop the disease.It is not known how many people, former children who received the same school lunches and bought uncooked burgers at McDonald’s, will get sick with mad cow disease in old age. But it is unlikely that this surge will be noticeable against the background of the tsunami of dementia [2].

A bigger problem is caused by the fact that prion is transmitted not only through meat, but also through blood cells [3]. That is why the British are forbidden to donate blood in Europe, there are restrictions in Britain itself. Cannibalism among the British has not been noticed, but since people with an as yet undiagnosed disease donated blood, it could potentially appear in anyone who received a blood transfusion in Britain in the 1980s and 1990s.Studies of the removed appendixes have shown that one in 2,000 Britons has accumulations of the prion form of PrP in their organisms [4].

And the biggest problem found in the mad cow study is that because prions do not contain nucleic acid, they are not killed by conventional surgical sterilization methods, “surviving” autoclaving. It is not known how many people carry latent prion infections and how many of them transmitted it in the hospital.

Finally, there is emerging evidence that neurodegenerative diseases such as Alzheimer’s and Parkinson’s, which exhibit prion-like protein aggregates, are also contagious [5].

Now, if you are offered to try something exotic – for example, squirrel brains, you better refuse, you already know that prions cross species barriers. In the United States, several cases of prion infection after eating protein brains have been reported [6]. However, elk meat is also not worth eating, since a particularly infectious type of prion is walking among North American elk and deer, which is transmitted to them through saliva [7].

It turns out that when it comes to safe food, the British turned out to be no better than the Chinese, although it was not tradition that let them down, but on the contrary, technical progress.And, alas, no one can guarantee that new diseases associated with a person’s desire to expand his menu with our smaller brethren will not appear in Russia either.

Literature
1. Creutzfeldt-Jakob Disease Fact Sheet ( National Institute of Neurological Disorders and Stroke ).
2. Abigail B. Diack, Mark W. Head, Sandra McCutcheon, Aileen Boyle, Richard Knight, et. al .. (2014). Variant CJD // Prion . 8, 286-295.
3. Alexander H. Peden, Mark W. Head, L. Ritchie Diane, E Bell Jeanne, W Ironside James. (2004). Preclinical vCJD after blood transfusion in a PRNP codon 129 heterozygous patient // The Lancet . 364, 527-529.
4. Abigail B. Diack, Robert G. Will, Jean C. Manson. (2017). Public health risks from subclinical variant CJD // PLoS Pathog . 13, e1006642.
5. Alison Abbott. (2016) The red-hot debate about transmissible Alzheimer’s // Nature .News feature.
6. Joseph R. Berger, Erick Weisman, Beverly Weisman (1997) Creutzfeldt-Jakob Disease and eating squirrel brains // The Lancet . 350, 907, 9078, P642.
7. Richard F. Marsh, Anthony E. Kincaid, Richard A. Bessen, Jason C. Bartz (2016) Interspecies Transmission of Chronic Wasting Disease Prions to Squirrel Monkeys (Saimiri sciureus) // Journal of Virology . 79 (21), 13794-13796.

90,000 COW RAGE: REAL OR IMAGINARY THREAT?

On January 25, 2001, at the Central House of Journalists, a press conference was held for journalists on the topic “Mad cow disease – is it in Russia? Reliable first-hand information.”It organized the scientific news agency “InformNauka” under the journal “Chemistry and Life”. The press conference was attended by Doctor of Chemical Sciences O. Volpina (Institute of Bioorganic Chemistry named after M.M. Shemyakin and Yu.A. Ovchinnikov RAS, Moscow), Doctor of Biological Sciences S. Rybakov (All-Russian Research Institute of Animal Protection, Vladimir) and Head of the Veterinary Department of the Ministry of Agriculture of the Russian Federation M. Kravchuk. The main problems posed at this press conference are highlighted by the special correspondent of the journal “Science and Life”, candidate of chemical sciences O.Belokonev.

The main problem of European farmers: ‘How to protect horned pets from a terrible disease?’.

In patients with spongiform encephalopathy, cavities are formed in the brain.

The formation of protein filaments is one of the main signs of the presence of ‘wrong’ prions in the brain. The electron micrograph shows a section of the brain of a scrapie-diseased sheep.

The normal prion molecule (1) synthesized in the nerve cell moves to the surface membrane, where it participates in the transmission of nerve impulses.

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About 15 years ago in England, thousands of cows were struck by a fatal disease. Mostly animals over 4 years old got sick with it. The symptoms are manifold. First, an uneven limping gait. At the last stage of the disease, the cow cannot rise at all – the hind legs fail. Secondly, animals lose weight, milk yield decreases, but most importantly, the behavior of cows changes – they become restless, fearful (sick cows are especially afraid of narrow passages, corridors and corrals), aggressive, grind their teeth, strive to separate from the herd, react sharply to light, sound, touch.In general, they behave like animals infected with the rabies virus. Hence the common name of the disease – mad cow disease. The “new” terrible disease turned out to be a long-known spongiform encephalopathy, which had nothing to do with “real” rabies. The “real” viral rabies – hydrophobia and spongiform encephalopathy have in common – only the symptoms and name, and the mechanism of occurrence of diseases is different.

Degenerative diseases, in which the brain is destroyed, turning into a kind of sponge, have been known for a long time.In sick animals, vacuoles – microscopic pores – are visible on a section of the brain under a microscope. A diseased brain resembles a porous sponge, hence the scientific name of this group of diseases – spongiform encephalopathy.

Spongiform encephalopathy affects cows, sheep (the so-called scrapie disease), goats, rodents and even cats. The animal dies from complete brain destruction. Similar diseases, although extremely rare, are found in humans: kuru disease (common among the Papuans of New Guinea) and Creutzfel dta-Jakob disease.The latter has been known since the last century and affects approximately one in a million elderly people. First, the patient’s coordination of movements is disturbed, then complete memory loss occurs, the sufferer is overcome by convulsions. As a result, the patient dies.

Scientists have long understood that the causative agent of spongiform encephalopathy “lives” in the brain and bone marrow of animals and humans. The highest concentration of the causative agent of the infection is in the oblong and middle parts of the brain. In meat, it is much lower.

Where did the epidemic come from

Why did a rare disease suddenly take on the character of a cow epidemic? About eight years ago, scientists suggested that the main source of infection for cattle in England is meat and bone meal obtained from sheep carcasses (among which there were animals sick with scrapies) and added to feed. True, bone meal was added to the cow’s diet 50 years ago, and the mad cow disease epidemic broke out only recently.The thing is that 15 years ago in Great Britain the technology of processing sheep carcasses into bone meal was changed – some stages of high-temperature processing were omitted. As a result, the pathogen retained its activity and the cows massively fell ill with spongiform encephalopathy. Most likely, mad cow disease is transmitted through feed, and not directly from one animal to another. Therefore, in a herd, sometimes only one or two cows are sick. But there is a high probability that the disease is transmitted to the cow offspring – from parents to children.

Mad cow disease is an English disease, and mostly English cows die from it. The incidence peaked in 1992, when tens of thousands of animals died in England. Measures were taken – no more bone meal was added to the feed, sick animals were destroyed, their meat was not used. The disease began to decline in England, but nevertheless isolated cases of mad cow disease have been reported in other countries of Western Europe.

Worse, in 1995, for the first time from a new disease, very similar to Creutzfeldt-Jakob disease, people began to die in England.In contrast to the “classical” Creutzfeldt-Jakob disease, mainly young people under 30 years of age fell ill with it. The official reason is eating beef contaminated with mad cow disease. More than 80 patients have died to date. However, there is no direct evidence that people were infected precisely through meat and meat dishes.

The relatively small number of victims of spongiform encephalopathy is little consolation. Scientists fear that the number of cases may rise sharply due to those who ate beef even before the introduction of sanitary examination at meat processing plants in Western Europe – the incubation period of mad cow disease in cows is from three to eight years.It is assumed that in humans it can be longer – up to 30 years. In some countries, those people who lived in England at the peak of the incidence of spongiform encephalopathy are under medical supervision, since they remain at risk of contracting Creutzfeldt-Jakob disease.

Mad cow disease is not a virus or a bacterium

For a long time, despite the efforts of many scientific teams, it was not possible to find the causative agent of mad cow disease.Infectious diseases are caused either by viruses or microorganisms – bacteria, microbes, fungi. But in the case of mad cow disease, no virus or microbe was found. In 1982, the American biochemist Stanley Pruziner published a paper in which he first suggested that mad cow disease and other types of spongiform encephalopathy are caused by a protein molecule that coagulates in an unusual way. He named her “prion”.

A prion is a common protein. Each of us has it on the surface of nerve cells.In its normal state, its molecule is twisted in a certain way. For some reason, it can unwind and acquire a “wrong” spatial configuration. “Wrong” straightened prion molecules easily stick to each other, protein plaques form on the nerve cell, and it dies. In place of the dead nerve cell, a void is formed – a vacuole filled with liquid. Gradually, the entire brain turns into a perforated substance, like a sponge, and the person or animal dies.

Where do the “wrong” prions come from? The cause of the disease (Creutzfeldt-Jakob, for example) may be a hereditary predisposition. A small error in the nucleotide sequence of a gene encoding a prion causes the synthesis of “incorrect” protein molecules with a “untwisted” configuration. Probably, such abnormal prions in humans and animals, in the presence of a genetic predisposition, accumulate with age and ultimately cause the complete destruction of brain neurons.

It is believed that when at least one untwisted prion molecule enters the human or animal organism, gradually all other “normal” prions begin to unfold in a similar way. How an “abnormal” prion molecule unfolds a normal prion is unknown. Scientists are looking for an intermediary molecule in this chain of chemical reactions, but so far without success.

For the scientific community, all of the above still sounds implausible. Such that an ordinary molecule that does not contain genetic material transfers information to other proteins – causing an infectious disease – has not yet been observed.It was like a revolution in biological science, a revision of the basic ideas about the mechanism of transmission of infection. Therefore, even despite the apparent lack of evidence of a prion model of spongiform encephalopathy, Pruziner received the Nobel Prize for his discovery in 1997, which attracted new scientific forces and financial support to the problem of mad cow disease (Frolov Yu. 1997 Nobel Prizes. Infectious protein. – ” Science and Life “No. 1, 1998).

The mechanism of diseases, which with the light hand of Prusiner began to be called “prion”, is being studied both in Russia and abroad (Zvyagina E.Protein inheritance. A new chapter in genetics. – “Science and Life” No. 1, 2000). Unresolved scientific problems give rise to panic in society and give food for the most incredible predictions. But although it is very difficult to study abnormal prions, since they are insoluble and resistant to the action of enzymes, there is hope that soon the mysterious disease will be subservient to humans. Or maybe we are threatened with trouble worse than AIDS – not only can you not find a vaccine for a new infectious protein, it is also surprisingly resistant to any kind of influences, and the mechanism of transmission of infection is not yet fully understood.

Pathogenic prion – find and neutralize

After it was shown that spongiform encephalopathy is caused by prions, to make a diagnosis, it became possible not only to examine a section of certain parts of the brain for the presence of voids – vacuoles, but also to determine the causative agent of the disease itself. Biochemical methods are used to isolate prion proteins and study them under an electron microscope – if their molecules are glued together, form threads, then the presence of pathogenic prions in the brain is beyond doubt.Immunological detection methods using specific antibodies to “untwisted” pathogenic prions (immunohistochemical analysis of sections and immunoblotting) are more sensitive than electron microscopy. Their essence is as follows: if antibodies interact with proteins isolated from the brain, there are pathogenic prions in it, and if the reaction does not proceed, there are no pathogens of spongiform encephalopathy in the brain. The biggest difficulty in determining is that the analysis is performed exclusively on the brains of slaughtered cows.That is, it is not yet possible to conduct research on live animals.

In recent years, a method for diagnosing Keitzfeldt-Jakob disease in humans has been developed. This is also an immunological assay using antibodies to abnormal prions. The reaction is carried out by taking samples of cerebrospinal fluid or making a section of tissue from the tonsils.

At large meat processing plants in Western Europe, immunological analysis is carried out in 10 hours, that is, while the carcass is being prepared for processing.If, nevertheless, pathogenic prions are found, the carcass is burned at a high temperature.

According to the latest data, a temperature of at least 1000 degrees is needed to completely destroy the pathogen of mad cow disease! Meanwhile, any bacteria can be easily destroyed by simple “boiling” in an autoclave for five minutes at 120 degrees. At first glance, the stability of the “wrong” prions seems fantastic. Although from a scientific point of view, this fact can be explained. After all, the loss of activity by a protein means a change in its spatial configuration.But the pathogenic prion has already been “unfolded”, it has already lost its natural structure, so more radical measures are required to neutralize its pathogenic activity than heating it above 100 degrees.

What is the situation with the diagnosis of mad cow disease in our country? In 1998, by order of the Moscow government, the All-Russian Research Institute for Animal Protection of the Ministry of Agriculture of the Russian Federation (Vladimir) received expensive equipment for analyzing animal brain slices for the presence of spongiform encephalopathy.Such equipment is not yet available in the CIS countries, or in most countries of the former socialist camp. According to S. Rybakov, Doctor of Biological Sciences, today the institute carries out an immunological analysis of sections of the brain of cows obtained from different regions of Russia. It is quite long – it takes 16 days to process one sample. The technique was developed jointly with the Institute of Bioorganic Chemistry named after V.I. M. M. Shemyakin and Yu. A. Ovchinnikov RAS. Fortunately, no pathogenic prions have yet been found in any of the 800 samples from 55 Russian regions.

Diagnosing a disease after the death of an animal is far from everything. It is also important to make sure that there is no mad cow disease in imported meat, feed and feed additives coming to us from abroad. And this is precisely where the greatest difficulties are. It is impossible to determine the presence of pathogenic prions in meat – the diagnosis is made exclusively by examining the brain immediately after the slaughter of the animal. Therefore, the control of meat and meat products can be reduced and is reduced only to prohibitive measures: to let in – not to let in.

All products, of course, are subject to mandatory border veterinary control at checkpoints, of which there are many in Russia – 291. The import of meat (beef and lamb) and meat products from England, France, Switzerland and some other Western European countries into Russia was banned back in September 1996 year. If any meat products (for example, in the form of food for dogs and cats) still go to the Russians, then the supplier must guarantee that they do not contain meat of European origin.

Since this year, the import of pedigree cattle from many countries of Western Europe has also been banned.

According to the current rules, the brains of slaughtered animals are examined at a meat processing plant and if pathogenic prions are not found, the supplier issues a certificate authorizing the export of meat and its processing. So we can only rely on the decency of suppliers from Western Europe and the conscientiousness of the Russian veterinarians-experts working there.

Our cows have diseases and worse ones

Again, mad cow disease is an English disease.But the British have already calmed down, they eat meat, as before, although the number of sick animals they have reached 176 thousand. But in Germany, where they heard about spongiform encephalopathy relatively recently and there were only a few cases of mad cow disease, there is a peak of hysteria: many simply refused meat. Fear has big eyes, and even in Russia, people began to fear the terrible mad cow disease: they do not eat beef, hamburgers in McDonald’s restaurants and canned meat.

Are these fears justified? Not yet.Indeed, in Russia to date, not a single case of mad cow disease has been recorded in cattle, and people with Creutzfeldt-Jakob syndrome, no more than one person per million inhabitants, which corresponds to the average population indicator, which does not depend on mad cow disease. … Once again, the service was served by Russian poverty: there was no money for imported bone meal and compound feed, our cows and sheep ate safe silage and chewed hay, and therefore remained healthy.

According to the head of the Veterinary Department of the Ministry of Agriculture of the Russian Federation, the chief veterinarian of Russia M.Kravchuk, spongiform encephalopathy does not threaten us yet. Anthrax, viral rabies, brucellosis, swine fever, foot and mouth disease, trichinosis, tuberculosis, which are also dangerous for humans, alas, are widespread. So the government has something to think about even without exotic spongiform encephalopathy – the threat of these diseases for the Russian livestock industry is not imaginary, but quite real. State veterinary institutions are not funded by the state at all. 103 thousand Russian veterinarians do not receive a salary, what can we say about test systems and equipment for performing expensive analyzes.So far, the law on the 2001 budget does not provide for funding for the veterinary service of Russia.

Don’t worry, this is rabies – Money – Kommersant

Russian officials have admitted that there have been cases of death from mad cow disease

Doctors call this disease Creutzfeldt-Jakob disease. In recent months, there have been statements at various levels that this deadly infection has not been noted in Russia. And now the chief infectious disease specialist of the Ministry of Health Mels Turyanov became the troublemaker.According to him, only in Moscow and only last year, the corresponding diagnosis was made to three patients. All of them have already passed away.

At the Burdenko Institute of Neurosurgery in the capital, which Turyanov mentioned, at first they refused to comment on his words. Then the deputy director Alexander Potapov made a denial. He said that the Burdenko clinic had never had such patients. Our neurosurgeons, – added Potapov, – know about this disease only from medical literature.

This is what is known about this disease, which in the West is compared to AIDS.

Mad Cow Disease is a new type of Creutzfeldt-Jakob disease known in medicine for a long time. The causative agent is not a bacterium or a virus, but a modified protein. American scientist Carlton Gaidushek received the Nobel Prize for this discovery.

For a long time it was believed that people cannot get infected with mad cow disease. But six years ago, 19-year-old Stephen Churchill died of spongiform encephalopathy in England.First known victim of mad cow disease. How many people in the world are infected with this infection is unknown. The incubation period is from five to forty years. As soon as the first symptoms appear, the disease begins to develop rapidly. In a few months, an absolutely healthy person turns into a weak-minded disabled person. And – inevitable death.

Scientists cannot yet determine the cause of the infection in cows. The most common opinion is that bone meal, which is added to livestock feed, is to blame.The disease cannot be detected at an early stage. The diagnosis – “mad cow disease” can be made only after death. Doctors are now comparing spongiform encephalopathy to AIDS. One hundred percent fatal, the same rate of spread. In Britain, in the homeland of mad cow disease, they are already talking about the fact that in the next 50 years from this disease 136 thousand British people can die.

So, officially the history of mad cow disease began in Great Britain. And it is in this country that the greatest experience has been accumulated in monitoring the disease, which is not yet amenable not only to treatment, but even to early diagnosis.

Today, when the whole of Britain is captured by the fight against foot and mouth disease, few people remembered that exactly five years ago, a group of Scottish scientists discovered a connection between the consumption of meat from cows with rabies and the onset of an incurable brain disease in humans – the so-called Creutzfeldt-Jakob disease …

What a panic then began! In one day, prices for famous steaks fell tenfold, and most importantly, the European Union banned the export of British beef. It took five billion pounds of taxpayers to fight the crisis alone.Nobody counted the losses of the farmers. 177 thousand 780 cows suffering from spongiform encephalospyathy or, in common parlance, “mad cow disease” were destroyed. In England, a computer database has been created that tracks the offspring and movement of each cow. The so-called cow passports were introduced.

The disease is believed to be caused by the use of compound feed made from poorly processed bone tissue of sheep, which in turn are sick, in turn, by a specific shaking. And to this day in England it has not been completely eliminated.This year alone, the Ministry of Agriculture informed us, 88 more cases of mad cow disease have been identified. However, the government prefers to report that excellent work has been done. Moreover, since July 1999, EU restrictions on the export of British cow meat not older than 30 months have been canceled.

France resisted the longest. London and Paris even sued over this in Strasbourg. In fact, the problem has not been solved yet. Scientists believe the disease may be common among older Britons.

HARRIET KIMBELL, professor, member of the government commission on spongiform encephalopathy: “We found it in a man aged 74. She may be hiding among other elderly people. We mistake her for Alzheimer’s. Only an autopsy will tell how widespread the disease is. And it is not very customary for us to open the bodies of elderly people. ”

The Minister of Health called the incident a national tragedy and apologized to his fellow citizens.

How serious are the fears that something similar to what our correspondent in London told about will happen in Russia?

On the air of our program – Minister of Health Yuriy Shevchenko (see.video).

Frenzied Beefsteak – MK

They call themselves stalkers. Every day, in protective clothing, with special passes, these people pass behind a high fence into the territory of the only Institute for the Protection of Animals of the Ministry of Agriculture of the Russian Federation in the whole country – and find themselves among … smallpox, salmonellosis, plague, foot and mouth disease … Groups of animals are exposed here to control infections … Nearby, in workshops, in three-ton bioreactors, all kinds of viruses “ripen”. And in the laboratory of little-studied diseases, samples from all over Russia are examined for the most, perhaps, the most famous disease in recent years – mad cow disease…

Brains in the hole

Everyone has already heard about mad cow disease – but who of us has seen infected meat? .. The infected tissue lies in my palm. A piece of brain, cut from an animal sick with mad cow disease, is still packed in a bright orange cassette. I am asked to put on a transparent mask in addition to thick gloves and white vestments: “Splashes can get into the eyes …”

A graduate student pulls gray twisted cords from a plastic bag.“The spinal cord of cattle,” they comment behind me. On the table, where they begin to cut unusual material, a vacuum is continuously maintained under the hood. Gloves only touch the work surface here. Everything that flows from the table goes into a special sterilizer. And the unusual taps on the sink in the laboratory – with long handles – are designed not for the hands, but for the elbows of scientists.

The sample, meanwhile, is placed in a special apparatus for dehydration. It will be “push-ups” for a day.The technician takes out another labeled sample that has already lost excess moisture. It is poured into a special cassette with hot paraffin, cooled, inserted into a special device – a microtome, which removes the finest shavings from the sample. The 5 micron plate is placed on glass, stained and viewed under a microscope. Before us, two color images appear on the computer screen.

– You see, – the professor shows me at the right picture, – everything is in order with our test sample from the Primorsky Territory.And on the left – the brain of a sick animal, brought by me by special permission from Ireland – we place it next to the samples under study for comparison.

In the tissue of an overseas cow, empty spaces are clearly visible in the place of dead neurons. The brain is all dotted with holes. Now I understand the official name of this terrible disease – spongiform encephalopathy …

– Is it scary to work with mad cow disease? – I ask the head of the laboratory of little-studied diseases, Doctor of Biological Sciences Sergei Sergeevich Rybakov.

– A person gets used to everything … The equipment is arranged so that the specialists are in contact with the material as little as possible. You saw: vacuum cleaning of air, automatic washing of the working surface of tables … Well, do not really follow the advice of one of the ministerial officials, who insistently recommended that those in contact with contaminated material wear … space suits!

The birthplace of mad cow disease has already been established. Most scientists around the world have concluded that the disease originated in 1986 in England.The reason was the addition of meat and bone meal made from the carcasses of sheep affected by a disease called scrapie to the cows’ feed.

“Scrapie has never been dangerous to humans,” Rybakov says. – This disease has been known for more than two centuries. The pathogen of scrapie was not transmitted to humans from sheep. But when the meat and bone meal made from the carcasses of sick animals was fed to cows, the pathogen changed its properties so much that it became fatal to humans …

“In Ireland, we went to a farmer where we saw a sick animal,” the professor continues.- The cow was afraid to go through the gate, her coordination of movements was disturbed, she tried to jump over non-existent obstacles, she tried to get up from the ground like a horse – raising her front legs first; a certain aggressiveness was also observed in the cows. Symptoms of classic rabies were manifested … But the causative agent of spongiform encephalopathy is not a virus, but a protein, which scientists have named a prion. Prion protein is normally found in any organism. It performs certain functions: it regulates copper metabolism, oxidation and aging processes.But a man gets an altered prion along with the meat infected with mad cow disease. This starts the process of converting a normal protein into an abnormal one ”.

It is useless to fry and boil meat infected with mad cow disease: the pathogen does not die during heat treatment. During the experiments, the infected tissue was heated to 150, 300, 500 and 1000 degrees. Complete inactivation of the prion (when it became non-infectious) occurred only in the latter case. Does not work on prions and most drugs.

Even lipstick can be lethal

– The meat of “mad” cows threatens mankind with progressive dementia. But after all, Creutzfeldt-Jakob disease (CJD) was described back in 1920 …

– Previously it was thought that this disease occurs spontaneously, due to gene mutations. It was rare enough: two sick people in a million. Moreover, all patients were elderly. Very young people are infected with new forms of Creutzfeldt-Jakob disease, obtained from animals with spongiform encephalopathy… While on a business trip to Ireland, I saw a sick girl who was only 22 years old. She did not remember what year it was, could hardly remember her name, did not move well – she had all the signs of premature aging. The doctors were unable to help her …

The government of foggy Albion wanted to conduct a complete survey of the population, but then, for moral reasons, abandoned this idea. How can an infected person declare that they are sick when the incubation period can last from 5 to 20 years?… The examination of the tonsils is now taking place only with their forced removal. There is no corresponding equipment for such studies in Russia. Professor Rybakov calculated: about 150 thousand dollars are needed to purchase equipment, reagents and establish intravital diagnostics in at least one medical institution!

– Can you get spongiform encephalopathy only by eating the meat of a sick animal?

– If only! .. Beef is added to sausages and sausages, even if it is written that they are made from chicken and turkey.By-products of infected cows are used both for the production of food and for the manufacture of certain medicines; low-melting fats are used in the cosmetic industry, in particular in the production of creams and lipsticks. Scientists count up to 7 thousand products and preparations that are obtained from the carcass of a slaughtered animal! It is clear that it is practically impossible to control such a volume of production. As for sick people, they can infect their fellows with spongiform encephalopathy only through blood transfusions.The whole world is now beginning to identify people who lived in England during the period of massive cattle disease, and exclude them from the number of donors …

– What barriers are put up in Russia on the way of “rabid” cows?

– First, there is a list of countries from which it is prohibited to import meat that is “untrustworthy” into Russia. Then, our country is a member of the International Epizootic Bureau, which is located in France. According to the International Veterinary Code, each country is obliged to monitor mad cow disease.The number of samples to be analyzed depends on the stock available. We have to examine about 400 samples every year. In 1998, the government allocated money to the institute to purchase equipment for postmortem diagnosis of this disease in animals. For two years now, samples of pathological material have been received from 60 regions to the laboratory of little-studied diseases. About a thousand samples passed through our hands – thank God, not a single case of animal disease with mad cow disease was detected. Our animals are not fed with meat and bone meal: for Russian livestock breeders it is a very expensive pleasure…

– As a specialist, don’t you think it absurd Moscow’s intention to purchase 100 thousand tons of beef in Germany at a price below the market price?

– It is believed that there is no horizontal transmission of the disease – from animal to animal – in mad cow disease. Vertical transmission – from cow to calf – is possible only in 10-20%. As for the delivery of meat, it is important what will be written down in the contract. An option is possible when the check of each carcass from the entire delivered batch is stipulated.

– Is it real – to check every carcass? ..

– Of course. Now there are methods that reveal a sick animal on the conveyor within 4-6 hours. In Ireland, for example, every carcass of a slaughtered animal is tested for mad cow disease. I was only at one private firm that analyzed over 1000 samples in one day. The lab assistants worked there in three shifts. One sample costs about $ 20, the carcass of a cow weighs an average of 300 kg. In a batch of 100 thousand tons of kilograms of meat, a complex analysis will cost two dollars more.It’s another matter who wants to buy it …

Scottish scientists drew attention to the fact that in animals with mad cow disease, the content of protein in the blood is sharply reduced. This means that not far off is the development of a technique for in vivo diagnosis of this disease in animals.

Meanwhile, in England as many as 180 thousand cases of infection of cattle have been registered. Next on the list are Ireland, Switzerland, Portugal, France, Germany … The British have already scored 5 million.adult livestock and a million calves. It is believed that about 700 thousand animals were eaten during the incubation period. It is predicted that spongiform encephalopathy will fall ill in England up to 80 thousand people. Pessimists say that the disease will take on the character of an epidemic in the country.

There are isolated cases of mad cow disease in cattle in many countries: in Canada, Kuwait, the Falkland Islands, Italy, and Spain. There is no guarantee that Russia will not add to this mournful list in the future.We do not know how to diagnose mad cow disease in vivo, and the incubation period for a mysterious disease is quite long …

90,000 A Muscovite was diagnosed with a rare fatal disease – Moscow 24, 14.05.2015

An extremely rare fatal Creutzfeldt-Jacob disease or mad cow disease was discovered in a Muscovite, according to the Moskva 24 TV channel.

In March, a woman went to the clinic with complaints of discomfort. However, she was not diagnosed with a disease and was simply prescribed vitamins.Meanwhile, the undiagnosed disease continued to progress. As a result, her condition deteriorated sharply and hallucinations began. Within two months, the woman went to bed and became completely immobilized. Now a Muscovite is in a rehabilitation center, does not react to relatives and friends, she needs to be turned over and fed through a tube.

In a closed case history, which is not handed out, the diagnosis of Creutzfeldt-Jakob disease is recorded, but doctors cannot officially diagnose it, since it must be confirmed.This can take months or years. All over the world, only 1-2 cases are detected per year, and in Russia there are no official statistics for this disease at all.

The patient’s children are struggling to get a diagnosis, albeit posthumously. According to them, this will allow other patients to get a chance for recovery and not waste time on diagnosis.

Creutzfeldt-Jakob disease is a pathological change in a protein in the brain tissue, which is caused by prions – proteins with an abnormal structure.According to various hypotheses, prions either appear in the brain on their own, or they can be infected from meat products.

Typically, people die about 3-12 months after the onset of illness, often from pneumonia. Approximately 5-10% of patients survive for 2 years or more.

Once in the body, harmful prions begin to destroy healthy brain cells. First of all, the central nervous system suffers, holes appear in the brain, and it turns into a sponge.When the disease has already penetrated the central nervous system, then the changes are irreversible, since the physical destruction of the tissue is taking place.

90,000 UK patients may contract mad cow disease after blood transfusion

April 29, 2013 4:41 pm

More than a thousand people can die from the human form of mad cow disease. This disease can be contracted in the UK after a blood transfusion.

British doctors fear that there is still a risk of contracting Creutzfeldt-Jakob disease after a blood transfusion.This is a rare disease and its symptoms may appear only after 10-15 years. The causative agents of infection are presumably prions – protein molecules. Prions infect the brain, and in those with the human form of mad cow disease, the central nervous system is gradually destroyed.

Doctors estimate that more than 30,000 Britons have latent cerebral cortex disease, according to The Telegraph. Doctors warn that the number of deaths from the disease could increase if the contaminated blood continues to be used.

Former Health Minister Frank Dobson has proposed developing a special national program to screen donated blood to prevent further infections that could lead to “horrific death.”

Frank Dobson stated that it is necessary “to do everything possible to check the donated blood.