Death of first cat
Two dairy farmers die of CJD
100,000 veal calves eaten by mistake
BSE situation in US
By Richard Rhodes
Mad Cows and Americans
© Copyright 1997 The Washington Post Sunday, March 9 1997; Page W13
Excerpted from Deadly Feasts, to be published this month by Simon & Schuster
The epidemic began with a veterinary mystery in southeast England 12 years ago. It led to the identification of a new variant of a fatal human brain disease last spring. Now U.S. regulators are preparing rules to protect Americans from 'mad cow disease'. Can we avoid Britain's calamity?
Since they handle them twice a day for milking, farmers know their dairy cows, big females with soft eyes, calm dispositions and udders like downy kettledrums. "It was the 25th of April 1985," remembers Colin Whitaker, a burly English veterinarian with a shock of dark hair, "when one of my dairy clients phoned up to say he'd got a cow behaving oddly and would I come and have a look at it." Whitaker lives in Kent, the county of hop fields and dairy farms in southeastern England that includes Canterbury and Dover. He drove to Plurenden Manor farm in central Kent, where his client maintained a herd of 300 milking Holsteins -- large-boned black-and-white animals, a valuable dairy breed.
One of the Plurenden Manor Holsteins was sick. "When you approached her," Whitaker recalls, "she would shy away. She was previously a quiet cow and had started becoming aggressive, rather nervous, knocking other cows, bashing other cows and so on . . . She would also at the same time become rather uncoordinated. If you shooed her, she would stumble, particularly on the back legs, and go down, and then scrabble along."
Whitaker examined the sick animal and diagnosed ovarian cysts, a common cause of aggressive behavior and nymphomania in cows. He treated the cow for the cysts, but across the next several weeks her staggering and stumbling worsened. "Eventually she went down," he says, "was slaughtered and went to the knacker's yard." ("Knacker's yard" is the traditional English term for a rendering plant, a place where dead animals and slaughterhouse wastes are processed into commercial products such as meat-and-bone meal.)
Seven more cows sickened and went down at Plurenden Manor in the next 18 months. By 1986, three other herds had been identified with three similar cases in far southwestern England. Dairy farmers and private veterinarians like Whitaker alerted the Ministry of Agriculture, Fisheries and Food (MAFF). Since epidemics typically begin with an index case -- a first focus of infection -- the distribution of the outbreak in widely separate areas was surprising, because the herds involved were closed, with no contact with other cattle and no importations. How did the disease jump from one end of England to the other?
MAFF's Central Veterinary Laboratory in Surrey, near London, began investigations. The condition resembled no disease of cattle previously known. The lab had difficulty acquiring properly preserved brains from suspect cows, but by the summer of 1987, it found "scrapie-associated fibrils," a marker of a fatal class of brain diseases known as transmissible spongiform encephalopathies. The lab scientists published their first brief report in the British Veterinary Record in October, defining a new disease of cattle they designated "bovine spongiform encephalopathy," or BSE.
Soon the media would nickname the new condition more sensationally for the nervous, aggressive behavior it provoked in normally peaceful animals, calling it "mad cow disease." Caricatures of befuddled, loony black-and-white cows became a staple of British cartoonists. Headline writers recycled Noel Coward's "mad dogs and Englishmen" into "mad cows and Englishmen" to the point of cliche. But the disease was no laughing matter.
By the end of 1987, BSE had appeared in herds throughout England and Wales, some 420 confirmed cases. More ominously, cases were increasing from month to month enough to predict that the numbers of animals dying would double annually -- exponential growth, a chain reaction of fatal disease. Epidemiologists, led by John Wilesmith of the Central Veterinary Laboratory, had begun collecting in May 1987 detailed information on 200 cases. They keyed their results into a BSE computer database. Then they looked for causes.
One important clue was the fact that BSE had broken out more or less simultaneously throughout Britain. All the early cases proved to be index cases, the first in their herds, which suggested infection from a common source. What did 200 cows from all over England and Wales have in common? Not veterinary or agricultural chemicals, the epidemiologists determined. Not genetics: The disease affected a number of different breeds. BSE couldn't have been imported into the herds, because many of them were closed. Not all herds had contact with wildlife such as deer that might carry disease. Scrapie, another spongiform encephalopathy, which infects sheep and is endemic in Britain, was an obvious possibility, but not many cattle farms kept sheep, so how would the cattle have picked up the infection? Nor had scrapie ever spread to cattle before.
Eliminating these and other potential common sources left one probable focus: food contamination. The fact that BSE occurred much more frequently in dairy herds than in beef cattle was a correlative clue. What foodstuff was fed to dairy cattle but not routinely to beef cattle? One in particular seemed to fit this restriction: supplemental protein in the form of meat-and-bone meal.
Beef cattle are fed grass or hay while they're growing, then fattened with grain. For milk production, on the other hand, a dairy cow requires a fortified diet. A good Holstein dairy cow produces some 30 to 40 pounds of milk per day, and to make so much protein requires a high-protein diet. Dairy farmers feed their cows high-quality hay and grain, but hay and grain alone are not enough to maintain high-volume milk production. For that, for centuries informally, but systematically and commercially beginning during the Second World War, dairy farmers have boosted their milking cows' rations with a twice-daily portion of protein supplement.
Soybean meal makes a nutritious vegetable supplement. Britain unfortunately doesn't grow much soybean. An alternative source of protein supplement in Britain and many other countries, including the United States, is meat-and-bone meal from the knacker's yard: the ground, cooked and dried remains of dead animals, including downer cattle (cattle found collapsed or paralyzed) and sheep dead of undiagnosed disease. Beef cattle are also sometimes fed meat-and-bone meal during the final fattening stage. Cattle (and sheep, pigs and chickens) are thus made cannibals in the interest of cheaper milk and meat.
High-quality animal protein is a relatively rare commodity in the world; not surprisingly, every part of beef and dairy cattle is eaten, recycled back into the next generation of animals or processed into commercial products. "You have just dined," Ralph Waldo Emerson once reminded a New England audience about the philosophical consequences of the human taste for meat, "and however scrupulously the slaughterhouse is concealed in the graceful distance of miles, there is complicity, expensive races -- race living at the expense of race . . ." Today we wouldn't say "race"; we'd say "species" -- species living at the expense of species. But sometimes meat bites back.
Once the disease that was killing British cattle was revealed to be a spongiform encephalopathy, contaminated animal protein was an obvious source. C.J. Gibbs Jr., Carleton Gajdusek and their colleagues at the National Institutes of Health in Bethesda had reported successful oral transmission of scrapie -- as well as kuru and Creutzfeldt-Jakob disease, related fatal brain diseases in humans -- to spider monkeys by unforced feeding of brain tissue in 1980. American physician Stanley Prusiner and Australian researcher Michael Alpers had shown oral transmission via cannibalism in hamsters in 1985. But meat-and-bone meal had been fed to cattle in Britain and throughout the world for decades without transmitting BSE. Had something changed?
To find out, Wilesmith and his epidemiologists arranged for three government veterinarians to conduct a survey of all the rendering plants in Britain. To give them a starting point, the epidemiologists needed to know when British cattle first became infected with BSE. They looked at the different ages of the 200 animals they were studying. Triangulating back, they estimated that exposure had begun suddenly and simultaneously in the winter of 1981-82. That estimate -- exposure to BSE in calfhood and an incubation period of four to five years -- has stood the test of time.
The three veterinarians carried out their survey in the autumn of 1988. Rendering plants are the goriest expressions of the recycling spirit, hellish places of steam, blood, grease and stink. There were 46 such plants in operation in Britain in 1988, of which 39 kept useful records. By chopping, grinding, cooking and dissolving on a Brobdingnagian scale, they produced tallow -- rendered beef fat -- and what the British call greaves.
The Oxford English Dictionary defines "greaves" as "the fibrous matter or skin found in animal fat, which forms a sediment on melting and is pressed into cakes to serve as meat for dogs or hogs, fish-bait, etc.; the refuse of tallow; cracklings." In modern practice, greaves were cooked down in stainless-steel vessels from the various materials delivered to the rendering plants from slaughterhouses, deboning plants, butcher shops and farms: fat trimmings, bones, offal (guts, heads, tails, blood, the "off-fall" of slaughtering, butchering and knackering), carcasses of cattle, sheep and pigs, even feathers from poultry -- in 1988, some 1.3 million metric tons.
Some of the plants processed the greaves further into meat-and-bone meal, which is a scab-colored powder (sometimes pressed into pellets) with a pungent, salty, bloody fecal smell. They used a number of different processing systems, some batch, some continuous. An American system for continuous rendering, which was cheaper than batch rendering, had come to dominate the market; the American system rendered wastes at lower temperatures than the processes it replaced. That was one significant change in meat-and-bone-meal processing that the investigating veterinarians discovered. Another was the abandonment of solvent extraction.
Flammable solvents that dissolved fat had been used for many years to enhance tallow removal. But an explosion at a British chemical plant in 1974 had led to the introduction of tough new standards for solvent use, and rather than investing in expensive new machines, the rendering industry had decided largely to forgo solvent extraction. The epidemiologists concluded that the combination of lowering processing temperature and abandoning solvent extraction had spread the disease.
Meat-and-bone meal is generally produced and distributed locally; when the epidemiologists learned that the only plants that had continued to use solvent extraction were two in Scotland that produced most of that region's meat-and-bone meal, they took the difference for corroboration of their theory: Scotland had been the last region of the country to report BSE outbreaks.
The British government hadn't waited for Wilesmith's epidemiological study to be completed to address the epidemic -- though it would later be criticized for moving too slowly nonetheless. In the spring of 1988, it had set up a committee chaired by an Oxford zoologist, Sir Richard Southwood, to study the problem and recommend government action. The committee had recommended imposing a ban on feeding ruminant-derived protein to ruminants (ruminants are hooved animals that chew their cud, including cattle and sheep), and that July, the government had complied.
Behind the ban was the assumption that BSE was scrapie, not picked up directly on the farm but passed to cattle through infected sheep waste incorporated into meat-and-bone meal by inadequate processing. If BSE wasn't scrapie, British veterinary scientists argued, what was it? No such native disease of cattle had been seen before the Plurenden Manor outbreak, at least not officially. In fact, there were other possibilities, and they would eventually be debated among scientists if not officially acknowledged. But the scrapie hypothesis was the Central Veterinary Laboratory's "primary hypothesis," according to Wilesmith.
Tragically, assuming that BSE derived from scrapie predisposed British officialdom also to assume that the disease was not likely to spread to humans from BSE-infected meat -- because scrapie had not spread to humans despite hundreds of years of eating scrapie-infected lamb and mutton. British officialdom concluded that however costly BSE might be to the cattle industry, the risk of BSE infecting humans was nil.
A month after the feed ban took effect, farmers were barred from selling cattle obviously ill with BSE. But this restriction did not extend to animals from BSE-infected herds, which might be incubating the disease without yet showing symptoms.
Nor did the British government pay adequate compensation to farmers and processors for their losses. A tall, ruddy, Cambridge-educated microbiologist at the Medical Research Council Neuropathogenesis Unit in Edinburgh, Hugh Fraser, remembers getting angry about the government's attitude -- "and," he says, "I don't get angry very easily.
"The real culprit is the British Treasury. The Treasury could have solved this whole blooming problem by putting in adequate compensation, buying back the contaminated meat-and-bone meal which they said it was illegal to use . . . The stuff continued to flow through the system."
Similarly, the government offered farmers as compensation only 50 percent of market value for their sick animals -- giving them inducement to market those animals for food before their symptoms became obvious.
Ironically, the triggering event of the BSE epidemic may not have been the feeding of contaminated meat-and-bone meal to cattle. Evidence turned up later that meat-and-bone meal had probably never been processed at a temperature high enough to inactivate the BSE agent. An increased percentage of meat-and-bone meal fed to cattle may in fact have triggered the epidemic.
"Indeed," reported the science journal Nature, "one factor involved in the spread of BSE in the United Kingdom was that inclusion of meat-and-bone meal in animal feeds jumped from 1 to 12 percent during the 1980s, a shift that resulted from a fall in the value of the pound and a corresponding increase in the cost of soya and fish meal." A blip in world financial markets may thus have begun the leak of BSE into the human food supply.
The Southwood Committee issued its report in February 1989. Three of the four members of the committee were retired from active science and none was expert on the spongiform encephalopathies. They emphasized the assumed link between scrapie and BSE and the improbability of scrapie passing to humans. They found "no evidence of maternal or horizontal transmission of BSE," meaning no evidence that it spread from cows to their calves or from cow to cow directly.
They endorsed the theory that the disease was spread in contaminated meat-and-bone meal from 1981 until the ruminant-feed ban was put in place in July 1988. They predicted that BSE would continue to infect cattle at the rate of about 350 to 400 head per month until 1993, would decline to a low level by 1996, and would subsequently disappear, resulting in a cumulative total of 17,000 to 20,000 cases.
When the Southwood report appeared, reported BSE cases were already up to 500 per month, higher than the steady-state numbers the committee had predicted. By the end of 1989 they would rise to 900 per month. By February 1995, they had accumulated to 143,109 confirmed cases, not the mere 20,000 the committee had predicted.
Late in 1989, MAFF ordered a further ban on the parts of cattle from BSE-infected herds thought most likely to carry the infection -- whether or not the animals had shown signs of infection. "Specified bovine offals," the parts were officially called, meaning brain, spinal cord, spleen, thymus, intestines and tonsils. An environmental health officer, David Statham, later told British television that when MAFF ordered the ban, "there was no guidance as to how that removal was to take place.
We had examples of slaughterhouses where they were splitting heads open with meat cleavers, trying to cut skulls open with chain saws, trying to suck the brain out through the hole that had been used to stun the animal." A veterinarian, Marja Hovi, described going to a slaughterhouse "to see the loading of the heads, just to check what the conditions were. I saw 150, maybe 200 heads being thrown into a truck in a heap, where you could see the brain material seeping out through the holes when the heads were upside down, running down onto the heads below and contaminating whatever was beneath.
When the heads arrived at the plant, the meat from the cheeks -- usually this is poor-quality meat -- was trimmed off for use in hamburger, for human consumption." A meat inspector, speaking anonymously, reported that "the specified offals were out of control. All of the material was supposed to be collected up, stained [to identify it as unusable] and removed from the building. But what we actually saw was specified offals being mixed up with other material." Statham, the environmental health officer, concluded: "We were being given mixed messages, particularly from the government. We were being given the message that this really wasn't a problem anyway and so this was maybe a bit of window dressing, as opposed to a serious public health matter."
Whether by negligence or by intention, the government was misleading the public into believing that beef was safe to eat. MAFF's chief veterinary officer, a gray, balding bureaucrat named Keith Meldrum, had insisted in public interviews since the beginning of the epidemic that it carried no implications for humans. In January 1989 he explained his reasoning on BBC television. "The evidence on BSE," he instructed the British public learnedly, "is derived mainly from our knowledge of scrapie, and there is no evidence, scientific or otherwise, that scrapie does transmit from sheep or goats to man. Using that as our model, we are fairly confident that BSE does not transmit to man."
The government's position made Alan Dickinson, director of the Medical Research Council Neuropathogenesis Unit, furious. As long ago as 1976, well before the BSE outbreak, Dickinson had written that "we should not assume, at this stage of our knowledge, that scrapie agents are never transmissible to man from infected meat, particularly as we know that some types of cooking would not inactivate the infectivity."
Studying the transmission of scrapie to goats, he had found the agent present not only in the tissues excluded by MAFF's later specified-offals ban but also notably in muscle -- which is to say, in meat. "The way you train the high-flying administrators, the mandarins," he says today, "can be summed up in one sentence. It is to train people to be at ease with their consciences when they take decisions about things they do not understand." The administrators were directing the British government's response to BSE, protecting the cattle industry. Dickinson, Hugh Fraser and others who had studied scrapie for decades were shunted aside.
The death of a cat in May 1990 caused a national panic in Britain. For a few weeks, beef consumption dropped by a third and London schools temporarily banished British beef from their menus. Max, a neutered 5-year-old male Siamese, shared a household in Bristol with four other cats. His owners had noticed in December that Max sometimes seemed to fall asleep standing up. A month later he began staggering. His head tilted permanently to the right. Sudden noise startled him. His skin twitched and the twitching evoked frantic licking and chewing.
By May, Max's back legs had failed him. At that point his owners mercifully had him euthanized. Naturally occurring spongiform encephalopathy had not been reported previously in cats. "No cause for alarm at all," chief veterinary officer Meldrum said on television on May 10. "This is only one cat death out of 7 million cats in the U.K." Sixty-two other domestic cats would die in the next four years before the government admitted that contaminated pet food probably killed them.
Richard Lacey -- an outspoken Leeds physician and microbiologist who has crusaded against the British government's management of the BSE epidemic -- is a ruddy, portly man with a high forehead and thinning white hair who would not look out of place in an 18th-century English coffeehouse. He attracted national attention for the first time in regard to BSE after Max's death when he told the London Sunday Times that the disease was still increasing among British cattle, implying that it was spreading through maternal or horizontal transmission, and that all the infected herds should be destroyed.
The Sunday Times translated Lacey's statement into a headline: " LEADING FOOD SCIENTIST CALLS FOR SLAUGHTER OF 6 MILLION COWS. " That blunt proposal summoned a carpet-bombing of reassuring press releases from MAFF. The minister of agriculture himself, a red-cheeked young Conservative named John Gummer, assured himself a place in British history by feeding his daughter Cordelia a hamburger before a mob of TV cameras while insisting that British beef was safe.
By the time of Max's death, a number of zoo animals had died of novel spongiform encephalopathies. A nyala (an African antelope) had been diagnosed all the way back in June 1986. Subsequently, oryxes, elands, kudus, a puma, a gemsbok and cheetahs would be stricken. Some of the zoo animals had been fed rations that incorporated infected meat-and-bone meal, and the biological characteristics of their infections matched those of BSE-infected cattle. But some of the kudus and elands and one of the oryxes were born after the introduction of the ruminant-feed ban, and one kudu was the offspring of a feed-infected kudu, which meant the disease may have passed from animal to animal in these cases, maternally or horizontally.
Richard Lacey appeared before the British Parliament's Agriculture Committee in June 1990. Although a Conservative member of Parliament who owned a meat-packing company tried to discredit Lacey's testimony, he held his ground and made several important points. One was that there was no evidence linking BSE with scrapie in sheep and in fact every reason to believe that the disease arose in cattle independently, since sheep and cattle had grazed together for generations with no known passage directly between them. In the absence of some test for BSE infection, Lacey argued, the only rational government policy was to slaughter the infected herds. Otherwise, infected animals that were not yet symptomatic would certainly pass -- were certainly passing -- into the human food supply.
Two British dairy farmers died of Creutzfeldt-Jakob disease in 1993. The government argued that the deaths could be accounted for within the normal incidence of sporadic CJD, which appears worldwide, seemingly randomly, at a rate of one case per million people per year. But a freckled, blond, blue-eyed 15-year-old, Victoria Rimmer, began coming home from school exhausted in May 1993 and the illness that followed could not be so glibly explained away: CJD is extremely rare in people under 30 years of age. Her grandmother Beryl, who was raising her, said later that Vicky "began losing weight dramatically and I thought she'd got anorexia. I started getting calls from friends and the school asking, `What is wrong with Vicky?'
As the weeks wore on, she became worse. She was falling everywhere, like you see those cattle falling. She kept saying to me, `What's the matter with me, Mum?' She just couldn't understand what was happening to her. We'd be out in the town and she'd have to sit down on the floor because she felt so terribly tired in herself. Between the end of May and August, she got a terrible pain in her arm and neck -- she was in agony, crying all the time. I took her to the doctors eight times but they said there was nothing wrong."
Beryl Rimmer eventually found a doctor willing to admit her granddaughter to a hospital for tests. He thought a measles virus had infiltrated Vicky's nervous system, but he found no virus in her spinal fluid. Next he did a brain biopsy. Three days after the biopsy, Vicky, who once "was more than normal," her grandmother says, and "full of life," slipped into a coma. The biopsy of her brain revealed spongiform encephalopathy. Mrs. Rimmer didn't understand the term and asked the doctor to write it down. He was afraid to do so, she remembers, and told her to look it up in a medical book. Eventually she convinced him. She showed the note to another doctor. He told her "spongiform encephalopathy" was mad cow disease.
A physician investigator from the British National CJD Surveillance Unit in Edinburgh visited Beryl Rimmer and examined Vicky. Mrs. Rimmer says he warned her to keep quiet about her granddaughter's condition. "Think about the economy," she says he told her, "think about the Common Market."
In March 1994, a 16-year-old schoolgirl, a Muslim born in England of Turkish-Cypriot parents, developed numbness in her face and fingertips and a backache following a fall. By August her speech had become slurred and her balance impaired. By September her memory was failing and she stumbled when she walked. She had never been treated with human growth hormone, never had tissue grafting or neurosurgery, procedures that have sometimes transmitted CJD. She normally ate lamb but sometimes ate corned beef and hamburgers. Her condition progressively worsened and she was hospitalized.
Also in 1994, an 18-year-old schoolboy was referred to a psychiatrist for depression. He told the psychiatrist that his memory had been failing for the past six months and that he had "gone nutty." A report of the progress of his illness appeared in the British medical journal Lancet the following year:
He subsequently developed visual hallucinations, delusions of reference, and an excessive fear of water and sharp objects, refusing to wash or shave. His parents noted that he had difficulty carrying out simple tasks such as unlocking a door or eating a boiled egg. He was admitted to a psychiatric hospital . . . His hallucinations continued . . . His gait deteriorated . . . For a period of eight years [earlier in his life] he [had] visited his aunt's farm annually and would have drunk unpasteurized milk and been exposed to cows. No cases of BSE have been reported in this herd.
The young man and the Muslim girl died in 1995.
There were only four prior cases of adolescent deaths from CJD reported in the medical literature up to 1995. At the beginning of 1996 -- besides Vicky Rimmer, the young man and the Muslim girl -- seven other adolescents and young adults had already died or were gravely ill.
James Ironside is a pathologist with the government CJD Surveillance Unit. In September 1995, studying a brain section from the 18-year-old boy who had recently died of Creutzfeldt-Jakob disease, Ironside found amyloid plaques so large that they looked under the microscope like chrysanthemum blooms. They were spread throughout the brain. Unlike the smaller plaques of ordinary CJD, these florid plaques were surrounded by a zone of spongiform change -- a destructive halo of holes.
Ironside had never seen this unusual pattern of damage before, but he knew that sporadic CJD pathology varied widely from case to case. He was startled, then, when another teenage case turned up almost immediately with identical pathology. He alerted the director of the Surveillance Unit, Robert Will. Will mobilized the unit's staff. Staff members quickly turned up six more suspect cases in relatively young people. At first Will and Ironside thought the youthfulness of the victims might be the reason for the similarities in their pathology. When the physicians checked the medical literature, however, they learned that the few rare cases of CJD in people under 30 in Britain and Europe showed no such florid plaques widespread in the brain. Late in 1995, Surveillance Unit staff began traveling the country interviewing the victims' families to rule out medical accidents or genetic predisposition.
By the end of February 1996, Will and Ironside knew they had an epidemiological cluster: eight cases of CJD in young adults that all showed a new neuropathological profile of florid plaques, early loss of coordination and late dementia. Will arranged to report the ominous new findings to the Spongiform Encephalopathy Advisory Committee, a group of scientists and physicians appointed to advise the British government on BSE. A SEAC meeting was set for March 8.
Ironside opened the meeting with slides illustrating the unusual pathology. The SEAC chairman, John Pattison, remembers the moment vividly: "Before he said anything, we could see what it was. It was dramatically different." Another SEAC member, Jeffrey Almond, recalls near-panic. "The atmosphere became genuinely quite tense. Some of us were genuinely afraid of what we were hearing. We were afraid that this really maybe indicated a transmission [of BSE] to humans."
Pattison scheduled another meeting of SEAC on March 16. By then, Will and Ironside had a ninth case. The committee considered a full range of actions, from leaving the present bans in place to destroying the entire British cattle herd, some 10 million animals.
SEAC reconvened with senior government officials on March 19 at the Department of Health offices in Whitehall. Will and Ironside now had a 10th case to report. All 10 showed the same unusual pathology. The debate went on until midnight. SEAC finalized its recommendations the next morning. They included destroying all British cattle over 30 months of age.
The language of medical reports is impersonal. The 10 new CJD "cases" were human beings, and those who loved them grieved their loss. One was Vicky Rimmer, then 18 and still barely clinging to life.
Another was the student who reported having "gone nutty." His name was Stephen Churchill. "About four months before he died," his mother told interviewers, "he started to stagger and it brought back memories of seeing the cows on the news. I mentioned it to my husband, could it be this disease that has to do with mad cows? He said, `No, it can't be, it's too ridiculous.' So I dismissed it."
Another was a 38-year-old housewife, Jean Wake, who had once worked as a meat chopper in a pie factory. After she died, in 1995, her mother had written Prime Minister John Major, asking if her death could be related to mad cow disease. Major had replied, "I should make it clear that humans do not get `mad cow disease.' "
Another was a 29-year-old mother of two, Michelle Bowen, who had worked in a butcher's shop. Comatose three weeks before she died, she gave birth to her second child, a son, named Anthony after his father. "She didn't know what day it was," her husband said bitterly of her delivery, "let alone know that she'd given birth."
Another was Maurice Callaghan, 30, of Belfast. Someone at the cemetery where he was to be buried panicked and issued the gravediggers protective clothing and rubber gloves.
The Muslim girl was not included among the 10, and four of the cases have not been identified beyond their ages and sex: three women, two aged 28, one aged 29; one man, aged 31, like Vicky Rimmer not then deceased.
The last case to be included was Peter Hall, a 20-year-old student, who was fond of hamburgers as a young teenager but who had become a vegetarian. He died in February 1996. "It was the cruelest thing to witness," his mother would say of his illness, "like babyhood developing in reverse."
Robert Will would tell a London newspaper of these 10 cases that "their brain tissue displayed a distinctive disease pattern closer to the damage inflicted on a cow's brain by BSE than the damage normal CJD inflicts on humans."
At the SEAC session on March 19, senior members of the British cabinet tried to suppress any announcement of the new-variant form of CJD (vCJD), arguing that the scientists might be wrong. The secretary of health, Stephen Dorrell, insisted that the public had to be told. Wednesday, March 20, speaking in the House of Commons, Dorrell informed a stunned nation that BSE had probably spread to humans from eating beef.
His announcement produced world-war-scale headlines throughout Britain and Europe. More British schools banned beef from their cafeterias. Beef sales plummeted until supermarket chains cut prices by 50 percent, after which three out of four customers began buying beef again. ("I love the taste," a dignified London matron told a television news crew. "I just buy the more expensive cuts.") The European Union blocked imports from Britain not only of meat but also of many beef byproducts, including, at least temporarily, such gelatin- and tallow-bonded goods as candies, cookies, lipstick and cough medicine. Many EU decisions require unanimous votes, and John Major's Conservative government retaliated against the beef ban by refusing British agreement across the board. The stalemate persisted for weeks.
I flew to London at the beginning of April 1996, within days of Dorrell's announcement, and was startled to see the words "Creutzfeldt-Jakob disease" in announcement cards in the windows of McDonald's explaining why the fast-food chain was no longer serving British beef. McDonald's decision to switch to Dutch beef at its 660 outlets would cost the British cattle industry $37.5 million a year, but it was not clear how much longer European beef might be counted safe.
Following Dorrell's announcement, the French public health service revealed that a 27-year-old Frenchman from Lyons had died in January with lesions identical to those of the 10 British vCJD cases. Until the EU ban, France had imported 88,000 tons of British beef annually as well as livestock. British meat-and-bone meal had flowed liberally to Europe until 1988, and there was evidence that British suppliers had illegally dumped hundreds of thousands of tons of contaminated product after that.
The London Sunday Telegraph discovered that more than 100,000 veal calves exported to France from Britain in 1995 never went to slaughter. Instead, the newspaper reported, "they were illegally absorbed into herds in France, Italy, Spain and Holland, reared to maturity and are now being sold for beef." So much for Dutch beef. MAFF responded by pointing out acidly that companies like McDonald's that were importing foreign beef might be getting British goods after all.
These legal and illegal exports of animals and meat-and-bone meal made European BSE statistics suspect. All the other EU states together had reported only about 400 cases of BSE since the British outbreak; statisticians argued, based on the British experience, that the number ought to be above 2,000. Many European countries slaughtered an entire herd with little or no compensation when a single BSE case appeared, discouraging farmers from reporting. Accepting the inevitable, the Federation of Veterinarians in Europe acknowledged in June that BSE had become not just a British but a European problem. Processing protocols in European rendering plants, a British study found, were no more likely than British methods to inactivate the BSE agent.
French and British researchers reported in June that they had successfully infected rhesus monkeys with BSE and that the resulting lesions looked like vCJD, with florid kuru plaques haloed with holes. "It's the first experimental argument -- and a very strong one -- in favor of a link" between the two diseases, the French researchers told the media.
Some prominent voices, however, continued to predict that the worst was probably over. A group of scientists from Oxford, MAFF's Central Veterinary Laboratory and the University of Colorado reviewed the BSE epidemic and concluded that BSE infection of cattle was "well past its peak, and seems to be in a phase of rapid decline . . . with all new cases of infection arising from maternal transmission. However, the numbers are small and this route of infection by itself cannot sustain the epidemic." The scientists predicted that "the epidemic is likely to fade close to extinction by the year 2001 [even] in the absence of culling."
The British government slaughtered 257,000 cattle over 30 months of age after the announcement in March 1996 of a link between BSE and vCJD in humans; a secondary program to cull the most afflicted herds of some 127,000 younger animals was also put in place. Licensed disposal plants were unable to keep up; farmers were forced to waste valuable feed to maintain animals that would only be destroyed, and Britain was running out of cold-storage space for the backup of unprocessed remains. Nor did the slaughter have any official scientific basis; it had been proposed to and accepted by the European Union on public relations grounds, to "restore public confidence in beef."
After an emergency cabinet meeting in late September 1996, citing "the new scientific evidence" forecasting a declining BSE epidemic for support, John Major announced that Britain would halt its slaughter of older cattle and would not begin culling younger animals pending further evaluation. Douglas Hogg, the new agriculture minister, faced down the farm ministers of the EU bluntly; the recent predictive study, he told them, showed that "BSE will in any event die out in 2000 or 2001" and that no slaughter or cull "would make a substantial difference to the rate of decline."
In the meantime, the beleaguered British government, stung by the popular and EU response to its March revelations, had locked up its data. Several researchers told me they had been warned of prosecution under the Official Secrets Act if they revealed information publicly. The predictive study that Major had cited to justify halting the slaughter program had used previously confidential MAFF statistics to arrive at its optimistic results. But word filtered through the scientific community in the autumn of 1996 that the maternal-transmission study on which those results were partly based was botched and that Nature had rejected it for publication.
Just as MAFF had restricted access to its animal studies and statistics, so did Robert Will of the CJD Surveillance Unit restrict information on his ongoing investigation of new suspect cases of vCJD. Another British case was diagnosed retroactively after Dorrell's March announcement, bringing the total to 11. But when French scientists reported two additional, highly suspect French cases in spring 1996, Will refused to reciprocate with information on further British cases he might be investigating. Will's position was that he did not want to exacerbate the public panic until his results were conclusive. In any event, someone leaked the information: The London Sunday Times reported in June that beyond the 11 previously confirmed in Britain and the one in France, the CJD Surveillance Unit was following five more suspect cases in the summer of 1996.
Worse, a minimum incubation period of 10 years, a reasonable estimate, would put the origin of all the cases back at the beginning of the BSE epidemic, when the number of infected animals entering the human food supply was small -- implying that many more deaths might follow from the increasing human exposure to infected beef in the later 1980s. In October 1996, vCJD was diagnosed in a 33-year-old British woman, bringing the number of confirmed cases to 13. A 14th victim, this one in France, was added to the list a few days later.
In 1989, to prevent the spread of BSE to the United States, the U.S. Department of Agriculture prohibited the importation of British cattle and zoo ruminants. The USDA found 499 animals on hand at that time that had been imported from Britain before the ban. Those were quarantined. Two American rendering associations asked their members in December 1989 to voluntarily discontinue processing sick U.S. sheep. In 1990, the USDA began active surveillance for BSE, examining the brains of several hundred downer cattle each year for signs of spongiform encephalopathy.
In 1992, the Food and Drug Administration surveyed rendering practices and found, an FDA veterinarian later wrote, that "the rendering industry voluntary ban did not appear to be fully implemented since six of the 11 renderers processing adult sheep with heads are selling rendered protein byproducts to cattle feed producers." The FDA's concern with sheep processing reflected an assumption that BSE derived from scrapie -- the unsupported assumption that also misdirected British efforts. In 1993, the FDA sent letters to drug, dietary-supplement, animal-product and other manufacturers urging them to use cattle materials only from non-BSE countries in their products. In 1994, still pursuing scrapie, the USDA proposed banning sheep offal from animal feed, but U.S. agribusiness contested the ban on the grounds that such processing would be too expensive and it was not imposed.
With Stephen Dorrell's announcement in March 1996 of a possible link between BSE and vCJD, the USDA ordered the 116 imported British animals still alive in the United States destroyed. The FDA announced in May that it would prepare regulations designed to prevent BSE in U.S. cattle. Livestock industry and veterinary groups agreed to institute a voluntary ban on feeding ruminant protein to ruminants, but no inspection system verifies compliance. The Centers for Disease Control and Prevention began a pilot surveillance for vCJD in five states.
The USDA decided to examine more downer-cattle brains; by late 1996 the total number of brains examined since the program began in 1990 had reached 3,200. None showed a BSE pattern of lesions, but they represented only a marginal sample of the approximately 100,000 downer cattle processed annually in the United States. A meeting of 70 U.S. animal and public health experts, sponsored by the USDA in the wake of the Dorrell announcement, nevertheless declared itself satisfied that existing safeguards were adequate. The group expressed satisfaction on two grounds: because BSE had never been identified in the United States and because the annual incidence of CJD had held steady at about one case per million population since 1979, with deaths among people under 30 years of age extremely rare.
The United States is probably not currently at risk from the British strain of BSE. That's the good news. But livestock feeding practices put the U.S. population at risk from animal strains of spongiform disease, which could spread quickly through the livestock population in contaminated feed and infect humans just as British BSE has done.
Are U.S. cattle a natural reservoir for an American strain of BSE? A better question might be: If Creutzfeldt-Jakob disease occurs sporadically in one in a million humans throughout the world, shouldn't there be correspondingly rare, sporadic spongiform diseases in other animals as well?
One intriguing hint is a recent estimate based on the history of four transmissible mink encephalopathy outbreaks in Wisconsin since 1947. If every Wisconsin outbreak of TME was caused by feeding downer cattle to mink -- a common practice -- then the prevalence of spongiform encephalopathy in those cattle was 1:27,500, which extrapolates to one case annually per 975,000 adult cattle in Wisconsin -- a ratio strikingly like the ratio of 1:1,000,000 for sporadic CJD.
A French veterinarian described what he called "a case of scrapie in an ox" as early as 1883. The first U.S. outbreak of mink encephalopathy preceded the arrival of scrapie in the United States, another indication that sheep were probably not the source. In 1980, Colorado State University pathologists reported a "spontaneously occurring form of spongiform encephalopathy" that killed 53 captive mule deer and one black-tailed deer between 1967 and 1979. Researchers found they could transmit the disease experimentally to healthy mule deer.
A similar disease turned up in captive elk pastured next to the mule deer, suggesting horizontal transmission. Since 1992, this "chronic wasting disease" has been identified in Wyoming deer and South Dakota elk. "The Department of Agriculture hates to hear me say this," C.J. Gibbs Jr. of NIH told me, "but spongiform encephalopathy in mule deer and elk isn't surprising to me. I've seen a letter from an 18th-century veterinarian to a physician describing a scrapie-like disease in deer in an English deer park. So my concept is that these diseases occur spontaneously in nature. It's a rare occurrence. It would normally be overlooked."
Richard Marsh, then at the University of Wisconsin, came to the same conclusion about BSE in cattle in 1988: "Because this new bovine disease in England is characterized by behavioral changes, hyperexcitability and aggressiveness, it is very likely it would be confused with rabies in the United States and not be diagnosed." By 1996, Marsh had concluded, "If spontaneous cases of [these] diseases can occur in humans, they likely also occur in animals. Normally not naturally transmitted, these spontaneous incidents can still pose a danger by the unnatural act of cannibalism [such as] the feeding of animal protein to ruminants."
The conditions exist in the United States for an epidemic of a native strain of BSE. There are about 100 million cattle in the United States, compared with fewer than 10 million in Britain. The United States produces about 3.6 million tons of meat-and-bone meal annually (incorporating not only slaughterhouse wastes but also the annual toll of 100,000 downer cattle), almost 10 times as much as Britain produces. At the beginning of this year, the U.S. livestock industry was feeding about 13 percent of this tonnage to cattle, about the same as the British do.
Meat-and-bone meal had previously been fed to adult cattle more than to calves -- to beef cattle to fatten them for market and to dairy cows to support milk production -- but that practice is changing in the United States. Beef cattle are typically slaughtered at 2 years of age or younger, when they might be incubating spongiform disease but would be unlikely to show symptoms. Feeding animal protein supplements to calves increases their exposure over time to any disease agents that might be lurking in their feed.
Richard Lacey thinks his British countrymen should slaughter their entire cattle herd, all 10 million animals, and give up eating beef. If they did that, they'd probably have to slaughter their sheep as well, since sheep are suspected of also having been infected with BSE. Neither prospect is likely, unless a new plague of vCJD ensues.
How many people will become infected remains to be seen. The British government, by making the wrong public health choices, has conducted a frightening natural experiment, allowing a lethal disease agent to spread through the human food supply, exposing the entire British population. There is every reason to believe exposure is continuing.
At some lower level of risk, the population of Europe has also been exposed to BSE. The lack of vCJD deaths outside France doesn't mean that the rest of the continent is free of human infection; the French deaths may indicate merely that exposure began there earlier. Nor do the limited number of vCJD deaths identified so far offer any basis for assessing the future extent of vCJD infection. That depends on the virulence of the disease agent. The ease with which BSE crosses species barriers and the fact that it is easily transmissible orally in small doses suggest that it may be an exceptionally virulent strain.
Occurrences of most epidemic diseases continue to decline from decade to decade in the advanced industrial nations. In the United States, for example, with the exception of AIDS , most diseases that physicians are required to report to the Centers for Disease Control and Prevention -- equine encephalitis, brucellosis, diphtheria, gonorrhea, hepatitis B, measles, mumps, polio, rubella and syphilis, among others -- have declined in the past four decades or disappeared. The mortality rate in New York City at the beginning of the 20th century was comparable to mortality rates today in the Third World, but few people in the United States or in Europe any longer have personal knowledge of the ancient killer diseases of humankind -- bubonic plague, smallpox, cholera, malaria. Good nutrition, improved sanitation and hygiene and new vaccines limit the risk of these infections.
But the British BSE disaster was not some throwback to antique conditions or mere bad luck. It followed in part from a pernicious anti-regulatory ideology that has taken hold in Britain and the United States in the last two decades. There's nothing inherently wrong with industrializing agriculture -- with raising chickens, pigs and other food animals under controlled conditions -- if such conditions are carefully arranged to limit disease and protect the public health.
Human beings, after all, have chosen to live under controlled conditions. We thrive with a roof over our heads and a healthy food supply; so do farm animals raised in confinement, which contract fewer diseases and survive to maturity in greater numbers than their "free range" counterparts. But eggs and chicken meat contaminated with salmonella, hamburger and fresh cider poisoned with deadly E. coli and beef infected with BSE all evidence a failure of government inspection, supervision and policy.
Until 1995, U.S. meat inspection had hardly changed since the reforms that followed Upton Sinclair's 1906 fictional expose The Jungle. Even with the passage in 1995 of a modernized meat-inspection system that for the first time included laboratory testing, the Republican Congress under Newt Gingrich and Bob Dole refused to exempt the measure from the so-called regulatory relief provisions of its Contract With America, delaying and limiting its effect. The Congress was arguably more interested in meat-industry profit margins than in consumer protection.
The British disaster makes it evident that the high-tech cannibalism of recycling animal protein risks spreading lethal disease. The practice continues in the United States for the same reason that it continues in Britain even as the death count rises: because the meat industry and its allies in government assess the risk differently from the scientists and physicians who know most about the transmissible spongiform encephalopathies.
The United States still has a chance to avoid a BSE epidemic. The FDA took an encouraging step in that direction at the beginning of this year when its outgoing director, David Kessler, announced that the agency proposed to ban the feeding of ruminant protein to ruminants. The announcement opened a 45-day period of public comment, after which permanent rules will be issued. The U.S. rendering industry immediately complained that the agency was overreacting. Veterinarian Don Franco, a spokesman for the National Renderers Association, told the Wall Street Journal, "The science just isn't clear enough. There are lots of theories, but there hasn't been any specific proof on how the disease is transmitted."
The Journal reported an industry estimate that a ruminant-protein ban would cost $1.6 billion in lost sales and for alternative disposal. Disposal of banned wastes could be a predicament as difficult for the United States as it has been for the British. Dennis Longmire, head of the large U.S. rendering firm of Darling International, characterizes the problem grimly: "You're talking about incinerating or landfilling millions and millions of tons of perishable animal tissue a year." The National Cattlemen's Beef Association, on the other hand, welcomed the move, saying that beef and dairy producers had already reduced feeding meat-and-bone meal to cattle.
But there are disturbing compromises built into the FDA's proposed ban. It would prohibit the use of tissue from cattle, sheep and goats in feed for those ruminants but would permit the continued feeding of ruminant blood, milk and gelatin. Ruminant tissue would continue to be processed into feed for chickens, pigs and pets despite the known susceptibility of pigs and cats to spongiform encephalopathy and the possible passage of the disease agent through chickens into their manure, which organic farmers use to fertilize vegetables.
Nor do the ubiquitous contamination of U.S. poultry and eggs with salmonella and the continuing outbreaks of human E. coli infection from contaminated meat inspire confidence in government inspection. From the rendering industry's perspective, the ban turns a valuable asset into an expensive liability. That reversal in Britain led to widespread cheating. Without rigorous enforcement, U.S. consumers have reason to fear the same result.
The United States has ample supplies of soybean protein, so its livestock industry could survive even a complete ban on feeding animal wastes to animals. Such a complete ban is the only certain way to prevent the passage of fatal spongiform encephalopathy among species -- including, pointedly, human beings. The industry's profit margin would narrow, since meat-and-bone meal is cheaper than soybean meal. But such an embargo is not even under discussion in Britain, much less in the United States. And as the rendering industry itself points out, it would mean disposing of millions of tons of animal wastes left over from meat processing -- a nearly intractable problem. Alternatively, we could follow Richard Lacey's advice and give up eating beef.
This article was excerpted from Deadly Feasts, to be published this month by Simon & Schuster. Richard Rhodes is the author of 15 books of fiction and nonfiction, including The Making of the Atomic Bomb, which received the 1988 Pulitzer Prize for general nonfiction.
@CAPTION: What veterinarian Colin Whitaker saw that day in April 1985 when he visited an English dairy farm marked the onset of the epidemic.
@CAPTION: British authorities' early assurances that beef was safe to eat infuriated Alan Dickinson, an expert in animal diseases. Near right, Agriculture Minister John Gummer and daughter Cordelia down hamburgers to make the government's case. Far right, a section of the brain of a cow infected with BSE, as seen through an electron microscope.
@CAPTION: Farmers and other meat industry workers discuss the crisis just a week after the British secretary of health, Stephen Dorrell, top left, informed a stunned nation that BSE had probably spread to humans from eating beef. To protect U.S. consumers, outgoing FDA Director David Kessler, bottom left, this year proposed a ban on certain feeds.