NR AQFH
AU Lacey,R.W.
TI How Now Mad Cow?
IA http://www.mad-cow.org/lacey.html
PT Review
VT
The risk of mass infection of BSE in humans is very real. At last the truth explained.
Richard Lacey is Professor of Clinical Microbiology at Leeds University. He has a degree in medicine from Cambridge University and a Ph.D in clinical microbiology from the Faculty of Medicine at the University of Bristol.
As well as publishing over 200 papers in scientific and medical journals, Professor Lacey has lectured extensively overseas and broadcast frequently on radio and television. His work has won him a number of prizes, including the Evian Health Prize for Medicine and the Caroline Walker Award for Science.
Professor Lacey has been an advisor to the British Government and is widely recognised as a world authority on mad cow disease.
What is BSE and how did it start?
BSE, better known as mad cow disease, stands for bovine spongiform encephalopathy, an infectious and incurable disease which slowly attacks the brain and nervous system of cattle. Spongiform encephalopathies are nothing new and are not confined to cattle. Scrapie, the form of the disease found in sheep, has been common in Britain for the past 200 years and a human version, Kuru, was once epidemic in tribal New Guinea. By late 1994, a handful of people in Britain had died from another human version, Creutzfeldt Jakob disease (CJD).
BSE has been epidemic in British cattle for the last ten years. The first confirmed cases were reported in late 1986 but it is believed that the first case may have occurred in Hampshire in 1985. By early 1995 it had been identified in almost 150,000 cattle and more than half of all British herds.
The exact origin of BSE is not known, but simplistic claims that it came from sheep are now discredited. BSE is an incurable disease caused by a mystery 'infectious agent'. The agent is not a virus or bacteria - nobody knows what it is. It has broken the most basic rules of biology. Any cure still lies at the very limits of present-day science.
What does it do?
The period between becoming infected and showing symptoms for spongiform encephalopathies is long in relation to the life span of the animal or human involved. For example, Kuru in humans can take as long as 30 years before the person becomes visibly ill. The disease bores into the brain and nervous system very slowly but once established it rapidly causes dementia and death. No treatment works. Post mortems show the brain to be sponge-like and full of holes, hence the name 'spongiform'.
In cattle, the first signs occur when the cow is put under any slight pressure or stress. Movement to a milking station might induce fear, panic and stumbling and the infected animal may stand away from the rest of the herd, holding it's head in an awkward posture. Despite a good appetite, the amount of milk she produces may drop and she usually loses a lot of weight.
As the muscles waste away, there may be twitchings, quiverings and shaking. Strange behaviour can occur, such as grinding teeth and sometimes the moo is odd. The cow over-reacts to touch and becomes very jumpy. Eventually, she will shake violently, stagger and in the end be completely unable to stand up.
It is the combination of a drop in milk and the fear that the cow will fall and be unable to stand again that makes the farmer call in the vet. If the animal does not recover, it is slaughtered and the head (with it's nervous tissue) is removed for examination as it is officially believed that this is the only infected part of the animal. This is unlikely as flesh also contains nervous tissue. It also ignores the possibility of the disease being passed from mother to calf.
The rest of the cow's body should be burnt but as many as 30% of infected carcasses end up in landfill sites where they could be disturbed by tractors, bulldozers, dogs or rodents. As BSE is an extremely strong disease, it remains infective even after years in the soil.
When cattle are killed for food, the same procedure applies - the head (and some other parts such as the spinal cord, spleen and thymus - 'specified offal') is removed. The Government say that people will not be at risk when they eat cows but the flesh (containing infected nervous tissue) is eaten and the bones are eventually made into gelatine which finds it's way into many products.
How widespread is BSE?
By late 1994, the disease had been identified in nearly 150,000 animals and in just over half of all cattle herds in Britain. Some scientists including myself believe that the only way to tackle the problem would be to destroy all herds with cattle incubating the disease.
BSE has affected all breeds including, significantly, Jersey and Guernsey cattle on their respective islands. The black and white Friesian Holstein cows are the most commonly affected simply because there are far more of them in Britain than other breeds. The youngest case so far recorded of a cow showing the symptoms of BSE was 20 months and the oldest 18 years.
The cattle industry in Britain is under constant pressure to produce more milk and dairy products at the lowest possible cost because we, the public, demand it. The price of our daily pinta is paid for dearly by the suffering of animals.
To provide as much milk as possible, cows are often fed protein-rich concentrated food made from the carcasses of other dead animals that have been sent to knackers yards or rendering plants. Cows only produce milk when they have had a calf. After a nine month pregnancy, the calf is removed within a day or two of birth. A few months later, while still producing milk, the cow is artificially inseminated again. Cows have around three or four pregnancies before their milk yield begins to drop.They are eventually slaughtered at six or seven years old, even though its natural lifespan would be 20 years or more. Most parts of the cow are used to make burgers, sausages, pies, stocks and pet food. Until 1989, this also included the brain.
More than 90 per cent of BSE cases have been in cows rather than bulls, simply because cows live longer. Beef animals are usually slaughtered around three years old and veal calves at six months. As BSE appears when the animal is around four to five years old, most beef animals are slaughtered before they are old enough to show symptoms, although they may have the disease.
Is BSE a danger to humans?
All the evidence so far suggests that humans are not immune from infection. The Fore tribe live in Papua New Guinea, a place unexplored by Westerners until the second half of the twentieth century.
Cannibalism, especially by women hoping to increase fertility, was common until very recently, and this led to an outbreak of 'Kuru', a human form of scrapie. Kuru killed up to 80 per cent of women in some villages but how it first started is unknown. Because it occurred within families and mostly amongst women, it was first thought that Kuru was inherited genetically. Scientists have since proved beyond doubt that Kuru is infectious and that the disease was transmitted by eating meat, in this case human meat.
If BSE can be transmitted to humans then the resulting illness is expected to be like our own form of Kuru - Creutzfeldt-Jakob Disease (CJD). As a spongiform encephalopathy, this is again a disease of the brain and is always fatal.
Like Kuru, patients first show symptoms of mental changes, such as problems with co-ordination, recent memory loss and slurred speech. Sometimes obvious twitching of muscles can be seen, the facial expression becomes fixed and the person may stumble and fall over. Over the next few weeks, the person becomes confused and unaware, unable to read or recognise even close relatives.
Towards the end of the illness the patient is unconscious and not reacting to anyone, often having fits or jerking spasms and is doubly incontinent, blind, deaf and speechless. Patients continue to be fed but are rarely placed on a respirator nor given antibiotics for infections, particularly of the lung. It is the latter which usually results in death.
During the post mortem, extreme care must be taken because the disease is incredibly infectious. The pathologist wears a mask, goggles, gloves, boots and a plastic apron and any instruments that have been used on patients suffering from CJD have to be thoroughly sterilised. For example, the silver needles used for the EEG (brain examination) must be treated with high pressure steam for prolonged periods of time or put through six successive heat cycles in a steriliser. Even then there is no guarantee of destroying the infection. If contaminated instruments are used on another patient (which they will be if the person was not visibly ill with CJD), the disease can, and indeed has been, transferred.
CJD is so feared by some people in the medical profession that they have refused to perform autopsies on patients suspected of dying from it. Some hospitals have even refused to admit patients suffering from it.
What is the connection?
It is now known that regular eaters of veal (and other beef products) are 13 times more likely to die of CJD than those who don't. The prospect of a huge number of people dying from BSE as CJD next century is very real; that is, CJD and BSE are one and the same.
What is being done?
Very little. The British Government has hidden the facts and fiddled the evidence at every stage of the investigation into mad cow disease. It has told expert scientists, including it's own advisors, to keep quiet in case the hugely profitable meat industry suffers. In May 1988, the government set up The Southwood Committee to examine the risks of BSE to both animal and human health. Extraordinarily, it had no experts on spongiform encephalopathies and none were consulted. Although experts in their own areas, none of the members of the Southwood Committee had done any research into spongiform diseases.
A month after the first meeting, the Government, on the advice of the committee, ordered the compulsory slaughter and destruction of carcasses of all affected cattle. It was already too late. Between the date of the first known case of BSE in late 1986 and the middle of 1988, at least 600 obviously diseased cows (plus an unknown number of animals not yet obviously ill) had been slaughtered and their meat had found its way onto supermarket shelves. Half the normal price of carcasses was paid in compensation, which encouraged farmers not to report suspect cattle. The real extent of the problem remained unknown.
The second recommendation of the Southwood Committee was to set up another committee to do more research, which simply admitted that the problem was too big. The next meeting of the committee was five months later, some indication of how serious the Government regarded the problem.
The report admitted that spongiform encephalopathies are a danger to humans and stated: 'With the very long incubation period of spongiform encephalopathies in humans, it may be a decade or more before complete reassurance can be given.' The Southwood Committee went on to say how they thought the disease was passed on, saying that eating was low down on the list of possible reasons. While admitting that all cows had got the disease by eating, they were suggesting one rule for cattle and another for humans. It was easy for a cow to get BSE through eating but very difficult for humans to get CJD by doing the same.
Two other general conclusions of the Southwood report were that the risk of vertical transmission of BSE (passing the disease from mother to calf) was non-existent (since proved incorrect) and that cattle would prove to be a 'dead-end host', which means the disease would stop at cows and not infect other species. This introduces the revolutionary biological concept of a non-infectious infection. Cattle are not a dead-end host. BSE has been spread to other species and this was known at the time of the report. The Southwood report stated that '...if our assessment of these likelihoods (of possible human infection) are incorrect, the implications would be extremely serious.' Their assessments have been shown to be incorrect. We do have a terrible crisis on our hands.
Who cares?
Evidence that the Government was less than concerned about the risk to the British public comes from the Tyrell Report, produced by the research committee set up as a result of the Southwood Report. For example, this said that the brains of cattle normally sent for slaughter should be checked to see if some animals had BSE and were not yet ill with it. This would have shown how big the problem really was. Not surprisingly, this has never been done, despite numerous requests from the UK Parliament, because it would have been 'too expensive'. Too expensive for the meat industry, that is. Once consumers realised that they were eating infected meat, profits would have plummeted.
The report also recommended monitoring all UK cases of CJD over the next 20 years (as a matter of 'urgency'!) to reassure the public that there was no link with BSE. At present 'monitoring' means that a researcher checks death certificates for CJD. That's it as far as the UK Department of Health is concerned. Of course, a real investigation was not planned because it would admit that the government was scared of a major public health problem.
It finished by saying that more research was needed and that the controls at that time to prevent the disease spreading were not enough. Overall, the report was an excellent analysis of the situation as it was in 1989 but many of the proposals it made were ignored by the government. This report, dated June 1989, was not released until January 9 1990, showing just how urgent the Government thought it was. By this time they had accepted that they did not know whether the disease could pass from cow to calf whether it was possible other species could get BSE, or that the recent suggested increase in sheep scrapie was the cause of the rise in BSE cases.
In April 1990, the Tyrell Committee became 'permanent', a surprising development as, according to the government, BSE was about to disappear.
The feed ban
As part of the cannibalistic merry-go-round that is an economically essential part of the meat industry, all the bits of animals from slaughterhouses unsuitable for human consumption are boiled up to produce fat and protein. The protein makes animal feed.
Apart from the obvious high risk of different infections being passed on, it seems strange that nobody had actually questioned the biological sense of forcing naturally vegetarian animals to become carnivores, eating the remains of other animals. This is probably what has caused the spread of BSE.
In June 1988, the government imposed a six-month ban on feeding animal protein to cows and sheep as it was thought this was the most likely way these animals would become infected. In December, the ban was extended for 12 months and laws stopped the sale of milk from cattle suspected of having the disease. Banning infected feed did not stop the rise of BSE. Cases rose from 500 per month in January 1989 to 900 per month in December 1989.
The 'mysterious agent' that causes spongiform encephalopathies has been found in many of the organs and tissues of animals. For example, cells from the spleen, thymus and tonsils ('specified offal' banned for use in animal feed in 1989) enter the blood and find their way to many organs including the liver and bones. The bones of old cows are one of the major sources of the protein gelatine, used in many foods from peppermints to pork pies. The greatest risk could come from bones because the procedures used to concentrate and purify gelatine could create a stronger source of BSE. With the passing from mother to calf of BSE confirmed in 1993/94, blood could also contain the disease, at least as far as cattle are concerned.
The problem, of course, did not go away. The number of BSE cases per month rose from 800 in January 1990 to 1,500 in December 1990. The Southwood Committee had predicted a maximum of 400 cases per month.
We were wrong but we're not sorry... After four years of Government reassurances that BSE could not infect other species, tests carried out in February 1990 proved the opposite. BSE was transmitted to mice by feeding and to other cattle by injection. Cattle were no longer 'dead-end hosts'. The disease had never been previously reported in cats but in May of the same year, a domestic cat died from a spongiform encephalopathy. Even then the Government stuck to its guns and denied that spongiform encephalopathies could jump species. In fact, that is the very nature of the disease. By the time 52 other cats had died in July, the government finally admitted that they had contracted the disease through eating 'pet food'. The question was no longer 'Can BSE affect other species?' but 'How many species will it affect?'
A month before, in January, trading standards officers revealed that infected cattle were still being sent to market because farmers were still only being given half of the normal price for their cows. A Ministry official denied that BSE was finding it's way into our food but some people weren't quite so convinced. In April 1990, Humberside County Council banned the use of British beef in school meals. The number of known cases of BSE passed the 10,000 mark.
In April 1991, the Ministry of Agriculture predicted that a peak in the number of BSE cases would occur in 1991 and the disease would disappear by 1994. By the end of the year, 25,025 cases had been confirmed in Great Britain, providing the first indications that, despite government claims to the contrary, the disease was being passed from cow to calf.
The following year, BSE was transmitted experimentally to seven out of eight species of mammal, including pigs and marmoset monkeys. In four experiments, this was by eating. A puma and a cheetah were also reported to have died of the disease. Evidence was mounting of an uncontrollable epidemic, with serious implications for humans.
CJD, the human form of BSE, claimed the lives of two dairy farmers who had tended herds with BSE infected cattle. The number of human CJD cases in Great Britain was nearly ten times higher than the annual number recorded 25 years earlier and twice as high as the number recorded five years earlier. Vicky Rimmer, a 15 year old Welsh girl, developed the symptoms of CJD, despite no family history of the disease or medical mishaps such as faulty blood transfusion. She was also extremely young considering the very long period it normally takes for symptoms to show. This meant that the disease was most probably contracted from an external source, more than likely food.
A doctor from the CJD surveillance unit examined Vicky and told her mother not to make her daughter's case public. According to the Daily Mirror (January 25 1994) he told her she should think of the economy and the Common Market.
More than 17,000 cases of BSE were confirmed in cattle born after the feed ban, with 500 cases known to have come from mothers which later developed BSE. This meant that BSE was infecting cows by means other than infected food. However, the government tries to explain this by blaming farmers, feed compounders and renderers for breaking the law - they accuse them of continuing to put ground-up sheep and cattle into cattle feed. This is manifest nonsense and is the last ditch attempt to deny the occurrence of vertical transfer of BSE (where the mother passes on BSE to her calf in the womb). The existence of vertical transfer means that the infectious agent must be in the cow's blood and will therefore be found in virtually all beef products.
In 1994 the government had still taken no action to control cattle being moved from BSE infected herds to other herds, nor had they taken any other steps to control the epidemic. The total number of BSE cases confirmed exceeded 137,000 by the end of August 1994 - more than six times the number predicted by the Southwood Committee in their 'worst case scenario'. However, in April 1994, it was admitted that cows did pass BSE on to their calves.
What can we conclude from this?
Basically two things. Firstly, almost 10 years after BSE was first identified, expert knowledge is still virtually nil. And, as if to cover this up, all the available evidence suggests that the government has carefully manipulated the facts to avoid doing anything about it. The main reason is to protect the huge vested interests of the meat industry - the cost of compensation for replacing six million infected cattle could run into billions of pounds. The bad international publicity from this would endanger UK food exports, tourism and even much of our industry. Secondly, there is a very real risk of mass infection in the human population. The government has made sure of that.
And while the time bomb of the twentieth century equivalent to bubonic plague ticks away, we all have to take responsibility into our own hands. The simple and safest answer of course is to stop eating animals. In the absence of any accurate, reliable or simply truthful information coming from 'the experts', the choice has to be yours.
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IN Bei Rindern soll die Milchproduktion nach 3-4 Schwangerschaften nachlassen. Wohl deshalb sollen die Milchkühe oft bereits mit 6-7 Jahren geschlachtet werden, obwohl sie über 20 Jahre alt werden können. Bislang starb das jüngste BSE-Rind mit 20 Monaten, das älteste mit 18 Jahren. Meist wird BSE jedoch mit 4-5 Jahren festgestellt. Wegen ihrer längeren Lebensspanne waren mehr als 90% der BSE-Rinder weiblich. Leider ohne Quellenangabe behauptet der Autor, dass regelmäßig Kalbfleisch konsumierende Menschen ein 13-fach erhöhtes Creutzfeldt-Jakob-Risiko hätten. Er weist daraufhin, das die britische Regierung keine Experten für Prionkrankheiten in das Southwood Committee zur Beurteilung des Übertragungsrisikos berief. Entsprechend unqualifiziert waren denn auch seine Einschätzungen und Empfehlungen. Die von der Regierung bezahlte Kompensation für BSE-Rinder betrug nur die Hälfte des normalen Verkaufswertes. Eine stichprobenhafte Untersuchung scheinbar gesund geschlachteter Rinder auf BSE soll nicht stattgefunden haben. Der Autor berichtet, dass die erst 15-jährige Vicky Rimmer 1991 CJD-Symptome zeigte. Nach Angaben des Daily Mirror vom 25.1.1994 forderte der behandelnde Arzt die Eltern auf, den Fall mit Rücksicht auf die britische Fleischwirtschaft geheimzuhalten.
PO Internet
SP englisch
OR Prion-Krankheiten L