BSE is the abbreviation for Bovine Spongiform Encephalopathy and is a disease of cattle; it is colloquially known as mad cow disease. The hallmark of the disease is altered proteins (albumen). Consumption of meat from diseased animals can cause Creutzfeldt-Jakob disease in humans. BSE has been known since 1985, but probably occurred in Great Britain in 1982, undetected at the time.
What is BSE (mad cow disease)?
BSE is a contagious disease of cattle, which first appeared in Great Britain. The acronym BSE stands for Bovine Spongiform Encephalopathy, which means spongy brain disease that affects cattle. The disease is caused by altered proteins that affect the animals’ brains, where they lead to degenerative (degrading) changes in brain tissue. The brain is decomposed and over time takes on a spongy appearance, with holes and gaps in which the proteins are deposited. The change in the brain causes the cattle to behave abnormally, becoming aggressive and suffering from movement disorders. After the first case in Great Britain in 1985, gradually more and more cattle showed the same symptoms and died after some time. By examining the carcasses, the changes in the brain were discovered. While initially uncertain, it has now been definitively clarified that BSE is also transmissible to humans, where it causes a type of Creutzfeldt-Jakob disease.
Causes
The cause of BSE is so-called prions; these are proteins produced by the body that have changed incorrectly and have taken on a different structure. They are found in the brain, spleen, lymph nodes and spinal cord. It is suspected that these prions were contained in the sheep meal with which the cattle were fed at that time. This meat-and-bone meal consisted of waste products from the slaughter of sheep and is actually not an adequate food for cattle, as they are herbivores. In sheep, a disease called scrapie has been known for a very long time, it has similar symptoms to BSE. In all likelihood, the prions were transferred to cattle through the use of diseased carcasses as feed. It has also been found that diseased cows can infect their calves while they are still in the womb. However, the exact incubation period of BSE is not yet known. This is the period between infection and the outbreak of the disease. So far, it has only been found that this time can range from 18 months to several years.
Symptoms, complaints and signs
Infected animals often show the first symptoms of bovine spongiform encephalopathy (BSE) at about four to five years of age. The first thing to be observed is [[ behavioral disturbance]]s. Cattle are either significantly more aggressive than before or overly fearful and distraught in response to their environment. If the disease progresses further, the animals lose control of their motor skills, especially their legs, and begin to sway and stagger. They also frequently buckle and fall. In a very advanced stage, the animals can no longer rise under their own power. In most cases, death occurs a short time later. Only then, after the death of the animal, can the disease be reliably diagnosed. An examination of the brain then shows the changes characteristic of the disease. In particular, severely swollen and dead astrocytes (supporting cells) can be observed. The shape of the brain changes drastically. The organ usually resembles a sponge with holes. The connections between the nerve tracts are broken due to the holes and are usually dead as well. Pathogenic prions, the triggers of the disease, can also be detected under the microscope. Eating the meat of infected animals can cause a form of Creutzfeldt-Jakob disease to develop in humans that is similarly destructive to the brain.
Diagnosis and course
The first symptoms of BSE are disturbances and abnormalities in behavior and usually appear in cattle at about four to six years of age. The animals become aggressive, sometimes excessively fearful, and they refuse to be touched. As it progresses, movement disorders are added. The animals can no longer control their limbs, they move strangely, they stagger and often they fall down. They bend their legs and can no longer walk.After the first symptoms appear, only weeks, sometimes months, pass before the animals die. BSE can only be diagnosed with certainty after death, as the brain must be examined for this purpose. When the brain tissue is examined through a microscope, it can then be seen that the supporting cells of the brain, known as astrocytes, have swollen and died as the disease progresses. One can see the sponge-like holey consistency of the tissue. Also visible is that the holes have broken the connections between the nerves, causing them to die as well. In addition, the microscope can be used to detect the triggers for BSE, the prions.
Complications
BSE occurs predominantly in cows; if the agent is transmitted to humans, serious complications result. Infection with the BSE virus initially results in increased sensitivity to pain and anxiety, as well as gait disturbances and paralysis, which increase the risk of accidents. Often, chronic sensitivity disorders also occur, which make everyday tasks considerably more difficult. Furthermore, behavioral disorders may occur, which in severe cases contribute to the development of anxiety disorders. Affected people are also often ostracized from the social environment and thus feel an intensification of the symptoms. In the further course, emaciation occurs and finally death after a few months. In less severe cases, infection can contribute to the development of diseases such as Creutzfeldt-Jakob disease. Possible complications result from the symptoms that occur in each case, ranging from urinary tract infections to pneumonia or entrainment rigidity. Typically, there is also difficulty concentrating, forgetfulness, paralysis, muscle paralysis, and visual disturbances, which also continue to increase as the infection progresses. Because of the severity of the complications, a physician should always be consulted if BSE is suspected.
When should you see a doctor?
If BSE is suspected, a physician should be consulted immediately. Medical advice is already required when initial symptoms appear, such as the typical memory and concentration disorders, increased irritability and insomnia. At the latest, when visual disturbances, twitching of the muscles and signs of paralysis occur that do not recede after a few days, a doctor should be consulted if BSE is suspected. This is especially true if there is a reasonable suspicion of infection. For example, if contact with infected animals has occurred, unusual symptoms must be taken particularly seriously. The same applies after an operation in which the surgical instruments may have been contaminated. Creutzfeldt-Jakob disease, which is the underlying cause of BSE, usually occurs between the ages of 55 and 80. If the above-mentioned complaints occur more frequently during this period, a visit to the doctor is recommended. Since the disease progresses rapidly, the symptoms should be clarified quickly. Immediate treatment can usually at least slow down the course of the disease.
Treatment and therapy
To date, there is no therapy for BSE. Infected animals usually die a few weeks or months after the first symptoms appear.
Outlook and prognosis
The prognosis for mad cow disease and the associated new variant of Creutzfeldt-Jakob disease suggests no prospect of cure. Instead, it has similar courses in domestic cattle and humans, always ending in the death of the affected individual. Affected cattle die within a few months (up to five) as a result of brain degeneration. This is preceded by motor problems, aggressiveness and the gradual failure of all the abilities that the cattle had before. In contrast, in humans afflicted with the form of mad cow disease known as nvCJD, the disease progresses somewhat more slowly. On average, 14 months pass before the affected person dies. The course is very similar to other variants of Creutzfeldt-Jakob disease in the middle and later stages of the disease. However, it has more psychiatrically relevant symptoms at the beginning. In particular, anxiety disorders and depression should be mentioned here. This is followed by sensory disturbances and then the cognitive and motor disturbances. Finally, death of the affected person always occurs due to entrainment rigidity, which means a suspension of all vital functions. The outlook regarding nvCJD is unclear.While potentially BSE-contaminated products are banned, not all questions regarding epidemiology have been resolved. However, it can be assumed that mad cow disease can be contained by appropriate protection of feed, cattle, and humans.
Prevention
One can prevent transmission of BSE to a small degree by separating diseased animals from the rest of the herd. However, because symptoms do not appear until long after infection, transmission may of course have occurred before then. In 2001, the feeding of meat-and-bone meal was banned throughout Europe as a preventive measure; however, it is now permitted again under certain conditions. People should therefore check carefully from whom the beef intended for consumption comes. It is best to only buy beef from a farmer you know and know how he raises his cattle. It is also advisable to buy only organic meat in the supermarket or organic market. Nevertheless, you should also pay close attention to the origin of the meat or ask the dealer.
Aftercare
The disease BSE affects cattle. It leads to death within a few weeks or months. There is no treatment to date. Authorities slaughter the entire herd if an animal is diagnosed with mad cow disease. The carcasses are disposed of separately to prevent infection. This procedure is intended to preclude recurrence. The feeding of meat-and-bone meal is believed to cause the emergence of BSE. The most effective means of follow-up is to isolate the cattle that show the typical symptoms. Research is ongoing. Mad cow disease can be transmitted to humans. Those affected then suffer from a variant of Creutzfeldt-Jakob disease. It is also not curable. No people have been affected in Germany so far. There have been a small number of sufferers in other countries such as Great Britain. Since a definite diagnosis is only possible after death, follow-up care can only be provided to prevent re-infection. This task cannot be performed by individual patients. Instead, the authorities have issued regulations to ensure that beef is safe. These include banning the feeding of meat-and-bone meal. Also, animal products may no longer be sold commercially if only one cow in a herd is sick.
What you can do yourself
Medically relevant self-help measures are not available in the case of this disease. Getting sick with a variant of Creutzfeldt-Jakob disease always means certain death for the affected person in case of severe disease progression. Based on the fact that the onset of dementia as well as the onset of paralysis will make the affected person a nursing case within a few months, he is merely well advised to use the remaining time. If the diagnosis of BSE is made or suspected, he should, out of self-interest, set out to perceive everything that he still wanted to perceive and can at that time. In addition, a good time should be worked towards with the environment. Not only during the last months or weeks, in which the patient must be cared for around the clock, does he need a caring environment. The time during the course of the disease should also be arranged in a meaningful way and according to the wishes of the patient. Since the disease is not contagious in the context of normal human contact, there is no need for relatives to take precautions. It is often the responsibility of those around the patient to continue to support them despite their possible changes in character and behavior. Thus, the feeling of not being left alone tends to make patients feel better about life.
