About mad cow disease
October 9, 2001 Update date October 13
As you all know, a dairy cow infected with mad cow disease was confirmed in Chiba Prefecture on September 10, 2001.
If mad cow disease is treated correctly, it will not be eaten and it will not pose a danger to humans, so we have been taking a wait-and-see approach for a while. I think you can feel it.
In addition to the staff of Hyogo Prefecture and Kobe City, where Kobe beef is one of the specialties, fattening farmers, slaughterhouses, and meat retailers, we have prepared further preparations to relieve everyone's anxiety as much as possible. We are here.
Although it is a small effort, we would like to provide correct information at our shop.
We will continue to collect information and post new information as soon as it becomes available.
Contents 1. First thing I want you to know 2. Is Kobe beef okay?
3. 4. What is mad cow disease? Effects on the human body 5 . 5. Why did meat-and-bone meal come to be made? Response in Japan
7. Occurrence of cattle of similar livestock on October 11
1. First thing I want you to know
■In general, "meat", "milk", "dairy products", and "pork" and "chicken", which are generally called "meat", are safe.
■ Parts of cows infected with mad cow disease that should not be eaten
Brain, spinal cord, retina (membrane of eyes), distal ileum (last part of small intestine)
* Transfer factors (prions), which are the source of infection, are recognized only in the above sites. No transfer factors have been found in other parts of the body, and even infected cows are said to be safe. In reality, cattle confirmed to be infected are to be incinerated. there is no.
■Infected by eating, not airborne or by contact.
■As for imported cattle, American, Australian (Aussie) and New Zealand beef are recognized as safe by the EU.
2. Is Kobe beef okay?
■Wagyu beef from Hyogo Prefecture, which will become Kobe beef, has a nose print on each cow when it is born, and is passed down from generation to generation. Food is strictly managed by keeping a record of what was given at what age, and meat-and-bone meal, which has become a problem, is not included. Kobe Beef and other specific brands of cattle are said to be "the taste is determined by the feed (marbled) is determined by the pedigree". Soybeans and wheat are boiled on their own and fed with their own feed, so they are lovingly raised by skilled fatteners.
(Family registrations are also created for each brand of cattle in Japan.)
■In a slaughterhouse that is also hygienically managed, a meat inspector strictly inspects before processing, and sick cows and cows suspected of being sick will not be slaughtered. Even after slaughter, only meat that has been rigorously inspected by inspectors at the Meat Sanitation Inspection Center will be served.
■On September 26, 2001, we conducted an on-site survey of all fattening farms in Hyogo Prefecture. We have received reports that no cows with
■Kobe beef (both Kobe meat and Kobe beef are the same thing without a definition of the name) is ranked according to the standards common nationwide after becoming "meat" in the first place. Strictly speaking, it does not include "internal organs", "head", etc. (The reason why "Kobe beef tsurami (cheek meat)" etc. is still sold is probably because it is the tsurami of cattle certified as Kobe beef.) Therefore, even cows infected with mad cow disease , Kobe beef, which contains the transfer factor that causes infection, does not exist, and all cattle that are confirmed to be infected are incinerated and will not be marketed as meat.
■After October 18th, we plan to introduce prion testing to all cows or all cows aged 30 months or older nationwide. Even if it is decided that only the Kobe Slaughterhouse will be able to inspect all cows and make a complete safety declaration, we are petitioning.
■At the Kobe market, producers are required to submit their own "Fatal Farmer's Certificate for Shipment and Fattening of Beef", and based on this, a "Certificate of Purchasing Carcass of Beef" is issued to purchasers.
Matters to be stated in the “certificate of fattening farmer shipping cattle” ・Breed, sex, and date of birth of shipping cattle ・Address and telephone number of fattening farmer (to respond to inquiries from consumers)
・Feed-related data: location and telephone number of the feed factory ・Amount of ingredients in the feed given, names of raw materials Proof that meat-and-bone meal is not used Matters to be stated in beef cattle carcass purchase certificate ・Based on the fattening certificate above, in addition to the safety of the fed feed, add the results of live and carcass inspections in the market.
3. what is mad cow disease
*Based on reports from the International Organization for Animal Health (OIE) and materials from the Ministry of Health, Labor and Welfare.
■Mad cow disease is called bovine spongiform encephalopathy, and is usually called BSE overseas. Because of its symptoms, it is reported in newspapers as mad cow disease and is generally known. (Hereinafter referred to as BSE for explanation.)
■BSE is a neurological disease of cattle that develops after a long incubation period (2 to 8 years), causes spongy changes in brain tissue, and is always fatal. Rarely occurs in cattle around 2 years of age, but most occur in adult cattle aged 4-5 years. (There is almost no onset under the age of 30 months.)
■Symptoms: There is no diagnostic method until the disease develops in the living body. Once the disease develops, physical strength decline, weight loss, milk yield reduction, various neurological symptoms appear, and gait ataxia may also be seen. In some cases, the person may fall or roll over due to exacerbation or general weakness. The number of days from onset to death varies from 2-3 weeks to 1 year.
■The outbreak was first confirmed in England in 1985. Studies have shown that it is transmitted through the oral route (by eating) and not by direct contact.
■The pathogen is an abnormal protein particle called a prion, which does not fit the definition of a normal virus. This fact and the long incubation period are factors that have not yet been elucidated, requiring a lot of time for experiments and research.
Originally, normal prion proteins are abundantly contained in the membranes of nerve cells such as the brain, but when pathogenic abnormal prions enter, they have the property of being denatured one after another upon contact with normal prions.
■There are various theories about the mechanism of the disease, but it is generally said that abnormal prions denature normal prions one after another, killing cells and forming a large blank. And there is no diagnostic method by serology.
BSE prions are highly resistant to physical and chemical treatments, and are hardly killed by boiling or temperatures that kill bacteria and viruses in general. According to the OIE standard, ``High-pressure sterilization at 133°C or higher and 3 atmospheres for 20 minutes or longer is required for tissue with a size of 5 cm or less.''
■As for meat and bone meal, which is considered to be the source of infection, it is said that meat and bone meal containing sheep prion called scrapie, which is a disease very similar to BSE, was used as feed for cattle.
■BSE and sheep scrapie are both caused by prions, but the two prions are not the same pathogen. The pathogen of BSE is considered to be a different pathogen because the degree of appearance of lesions is extremely stable compared to that of scrapie in sheep. Also, sheep scrapie does not infect humans.
4. Effects on the human body
■Unfortunately, research has gradually revealed that BSE can infect humans. The disease is called new variant Creutzfeldt-Jakob disease. The pre-existing Creutzfeldt-Jakob disease has never been proven to be caused by BSE, so it was initially thought not to infect humans. Advances in research have clarified the differences between the new variant Creutzfeldt-Jakob disease, which is thought to be caused by BSE, and the preexisting Creutzfeldt-Jakob disease.
■Reason (results of investigation of 10 patients suspected to be caused by BSE)
• The average age of normal Creutzfeldt-Jakob disease is 65 years, but the new strain is unusually young, ranging from 16 to 36 years. (3 out of 10 are in their late teens, 5 are in their 20s, and 2 are in their 30s)
・The EEG pattern seen in the normal one was not seen in the new model.
The average survival time after onset of 10 people was 13 months, compared to 6 months for normal cases.
All patients had spongy lesions in the brain, and autopsies of the deceased showed formations of large plaques of the prion protein. (lesions different from normal patient brains)
■In subsequent studies, it was also announced that the clinical course was almost the same when mice were infected with the lesions of cows with BSE and people with new Jacob's disease.
■ It can be said that human infection is certain, but the people who have been infected with BSE (more than 100 people so far) are all Europeans. I continued to eat dangerous parts such as the brain and spinal cord as well as meat during the period. In Japan, the food culture is different and it is not customary to eat brains, and it is known that there is already a disease called BSE that can be transmitted to humans. In Japan, cows infected with BSE are obligated to be incinerated. It is a pity that the cattle in question became meat-and-bone meal this time because of a lack of understanding. However, as a result of this, regulations have become more stringent than ever, and efforts are being made to ensure that foods that contain transfer factors that cause them, not to mention dangerous parts, are not circulated.
5. Why did meat-and-bone meal come to be made?
■We have not found any clear literature on this, so this is our opinion (if there are any parts that are not correct, please point them out). It was incinerated due to hygiene issues. In Japan, in the past, there were incinerators almost everywhere next to slaughterhouses. In the past, it was discarded after being incinerated, but it is used as feed, fertilizer, etc., because it contains a lot of nutrients such as calcium and protein. is now available.
■The sudden discovery of mad cow disease after 1985 is said to have been caused by the oil crisis of the 1970s. Until then, meat-and-bone meal had been sufficiently heated, and prions, which are considered pathogens, had died to some extent, but in the latter half of the 1970s, the method of cooking was changed to save fuel, and the heating time was shortened.
(October 1 Nihon Keizai Shimbun 25 Chemistry 13th Edition Excerpt from an article by Professor Emeritus Kazuya Yamauchi of the University of Tokyo (Director of the Japan Institute for Biological Research, Virology))
■ At present, it is known that prions, which are resistant to dry heat, can be killed by autoclave at what atmospheric pressure, over how many times, and for how long. It can be said that cattle disease is an artificial result of people forcing cows to eat meat, which was originally herbivorous.
6. Response in Japan
■August 6 A dairy cow (Holstein, female, 5 years old) raised in a dairy farm in Chiba Prefecture was slaughtered at a slaughterhouse. Conduct inspection. (*The cow is not edible.)
On August 15th, it was confirmed that it was negative, and it was decided to treat it as a normal pathological appraisal subject. to implement.
■September 10: Immunohistochemical test results were positive, and the material and domestic test results of this cow were sent to the British Veterinary Research Institute, an international reference laboratory.
■On September 10, the BSE task force was established in the Ministry of Agriculture, Forestry and Fisheries.
・Implementation of a survey of where the cattle were introduced and the feeding situation.
・From September 12th to 25th, the Independent Administrative Institution Fertilizer and Feed Inspection Center conducted emergency on-site inspections of all compound feed factories that manufacture feed for cattle.
・From September 12th to 30th, we requested prefectural livestock departments to conduct a survey of all dairy and beef cattle raised in Japan.
■September 21st, we received test results from the British Veterinary Research Institute, diagnosing this BSE-like case as bovine spongiform encephalopathy.
■ Negative test results have been confirmed for all similar cases of bovine spongiform encephalopathy discovered by October 2nd.
■After October 4th, imports of meat-and-bone meal from all countries will be temporarily suspended, and production and sales of meat-and-bone meal including domestically produced meat-and-bone meal and feed and fertilizer including meat-and-bone meal will be temporarily suspended. Make a stop request.
■ From October 18th, BSE testing will be introduced for all cattle at slaughterhouses.
7. On October 11, a pseudo-infected cattle occurred
■On October 10, the Ministry of Health, Labor and Welfare inspected 26 of the 303 cows that were slaughtered at the Tokyo Central Wholesale Market Meat Market on October 10, and one cow suspected of having BSE was found. This test was conducted as a practical training prior to the all-head test scheduled from the 18th, but it was negative in the subsequent detailed test.
■Is the inspection from the 18th reliable?
The test scheduled to be introduced from the 18th is a screening test called the ELISA method, and although this test does not misdiagnose a positive as a negative, it is said that the probability of misdiagnosing a negative as a positive is 3%. First of all, this test extracts suspected positives, and the system is designed to examine those that are caught by more reliable tests. Therefore, in the future, all cows will be tested, and I think that there will be a certain amount of cows that are suspected of having BSE, like this time. Our view is that it is safe to say that cows infected with the disease will no longer be on the market.
