Another young deer hunter down
Surgery linked to increased risk of sporadic CJD
nvCJD cases reach 39
Nannying' beef ban has attracted barrage of criticism
Scrapie in Idaho, Washington
79 Cases of BSE Confirmed in Irish Cattle
SEAC agonizes over cheek meat and tongues
Not much case for beef-on-bone ban
NY Times: Weighing mad cow risks in American deer and elk
Update on blood withdrawalsBR> Human growth hormone marketing
5 March 99 email correspondence-- A 27 year old in Oklahoma is said to have been positively diagnosed with CJD. Possible risk factors include being a deer hunter, driving a fertilizer truck, and looking after cattle. A recent Lancet article and earlier epidemiological studies suggest these are risk factors.
-- 53 year old female deer hunter, Kansas. Also ate organ foods or brain. Had numerous surgeries.
-- Another deer hunter CJD victim is reported from Michigan, 60 year old. The individual has lived in Michigan for last 4 years after coming from California. Iatrogenic CJD has been ruled ou; Diagnosed with narcolepsy initially, cataplexy, then diagnosed as Whipple's disease but eventually eventually came to the conclusion of CJD.
Comment (webmaster): Whipple's disease is a new misdiagnosis of CJD, though not totally off the wall. It is not likely that too many cases of CJD are lost to this diagnosis. Whipple's disease is a rare, generalized inflammatory disorder, affecting mostly middle-aged white men, due to a recently described gram-positive rod-shaped bacterium, Tropheryma whippelii, which cannot be cultured but is found in sewage wastewater. It is usually curable with trimethoprim-sulfamethoxazole though formerly thought to be fatal.
Intracerebral Whipple's disease is sometimes included in the differential diagnosis of patients presenting with progressive dementia and cognitive decline. Lesions have been observed in the hypothalamus, cingulate gyrus, basal ganglia, insular cortex, and cerebellum. It is multisystemic and can have many non-neurological manifestations, such as aortic valve endocarditis, arthralgias, fever, abdominal lymphomas, polyserositis and cachexia. The diagnosis of Whipple's disease can e confirmed by polymerase chain reaction analysis of biopsy material and cerebrospinal fluid using 16S rRNA.
A recent study on the accuracy of the clinical diagnosis of corticobasal degeneration (CBD) included a familiar cast of characters: progressive supranuclear palsy, Parkinson's disease, diffuse Lewy body disease, multiple system atrophy, postencephalitic parkinsonism, Pick's disease, CJD, Alzheimer's disease, vascular parkinsonism, and Whipple's disease. [Neurology. 1997 Jan;48(1):119-25.]
Wed Mar 3, 1999 DoH Web siteThe 1 March 1999 Report on nvCJD figures to 31 January. The Report shows total definite plus probable nvCJD to 31 January has reached 39 cases. The next table will be published on Monday 12 April 1999.
[Note DoH re-wrote the last month's statistics to sneak another 3 cases into Dec 98, even though the number of referrals stayed fixed at 150. A third case of familial CJD was also identified retrospectively . As always no genetic details or ages were released. The revised data better fit rising incidence data from Sept-Oct-Nov. One possible motive for moving 1999 cases back to 1998 would be to make 1999 look like a declining year, if events play out that way. However, 16 referrals in Jan 99 projects to 192, in line with earlier statements of about a 1/3 increase in referrals.-- webmaster]
Deaths of definite and probable cases in the UK Year Referrals Sporadic latrogenic familial GSS nvCJD Total 1985 - 26 1 1 0 - 28 1986 - 26 0 0 0 - 26 1987 - 23 0 0 1 - 24 1988 - 22 1 1 0 - 24 1989 - 28 2 2 0 - 32 1990 53 28 5 0 0 - 33 1991 75 32 1 3 0 - 36 1992 96 43 2 5 1 - 51 1993 78 38 4 2 2 - 46 1994 116 51 1 4 3 - 59 1995 87 35 4 2 3 3 47 1996 134 41 4 2 4 10 61 1997 161 58 6 4 1 10 79 1998 150 39 3 3 0 15 60 1999 16 0 0 0 0 1 1
PA News Mon, Mar 1, 1999 By Michael Clarke, Deputy Political Editor, PA NewsThe controversial beef on the bone ban was introduced in December 1997 by former Agriculture Minister Jack Cunningham after fears that T-bone steaks, beef ribs and oxtails could contain the agent that causes a form of human "mad cow disease". Current Agriculture Minister Nick Brown last month dashed farmers' hopes that the ban might be lifted, when he said there was still a risk of people being infected with new variant Creutzfeldt-Jakob Disease (CJD). He cited advice from the chief medical officer, Professor Liam Donaldson, and told MPs he had to "err on the side of caution". But he has pledged to review the situation in August.
Butchers and restaurateurs have condemned the ban as a "nannying" over-reaction to the BSE crisis and say the public should be warned about the risk and allowed to make up their own mind. Scientists have also questioned the value of the ban. [Unclear what -- if any -- study the reporter is thinking of here -- webmaster]
The Government's chief scientific adviser, Sir Robert May, said last month there was "not much of a case" for maintaining the ban. And Professor Hugh Pennington of Aberdeen University, who investigated the E.coli food poisoning outbreak, said that "in a rational world" beef on the bone would simply be labelled with a health warning and sold.
But there are fears that allowing beef on the bone back on to the market could provoke the European Commission to re-impose its devastating worldwide ban on all British beef exports, imposed in the wake of the BSE crisis in March 1996 and only lifted last year.
1 Mar 99 correspondence"Last year Idaho implemented a mandatory scrapies eradication program. In my opinion it leaves a lot to be desired. Also, recently 350 Suffolk sheep were destroyed in eastern Washington to prevent the spread of scrapies. One ewe was confirmed as having the disease. It's been reported (Jan 20, 1999) as many as 750 sheep may have been infected and 400 had been sold. State officials were trying to track them down."
Chronic wasting disease clarification: passage of CWD to goat was mentioned in a Williams and Young 1992 paper, Rev Sci Tech 1992 Jun;11(2):551-67 . The goat experiment was done in isolation facilities (which rules out contact with deer or sheep or any other TSE). One goat got a spongiform encephalopathy 6 years after intracerebral inoculation of brain material from a deer with CWD. The goats were inoculated in 1983. Only goats were used in this experiment - no cattle or sheep. The experiment is not yet published as there were problems with the immunostaining (possibly sat in formalin too long) and the sample sizes used were very small."
Comment (webmaster): This was a far-sighted experiment that deserves better than to sit on the shelf for 16 years. While successful transmission comes as no great surprise (RF Marsh saw CWD transmission to primate, a far wider sequence gap), the incubation period is very long and it seems not all goats succumbed. This does not imply that scrapie was not the original source of CWD in confined deer and elk because mouse-hamster shows clearly that the species barrier may be assymmetric.
There is not much information available from RF Marsh's lab notebooks. Two squirrel monkeys were inoculated with CWD in 1980 or 1981, which implies mule deer as source. Both animals were euthanized due to extreme suffering approximately a year and a half later. One was noted as "affected" and on the other no diagnostic information was recorded. Successful passage was noted in the text of a 1998 article,
Virology. 1998 Nov 25;251(2):297-301. Bartz JC, Marsh RF, McKenzie DI, Aiken JM
Mon, Feb 22, 1999 COMTEX NewswireThe age profile of the discovered animals was as follows:
Year of Number of Year of Number of Birth cases Birth cases 1981 1 1988 22 1982 2 1989 20 1983 2 1990 40 1984 12 1991 57 1985 20 1992 68 1986 28 1993 40 1987 21 1994 11Farms of suspect animals are visited and the herd is immediately placed under official restriction and quarantine. An inventory of the herd and an initial epidemiological investigation is carried out. After monitoring, suspects are slaughtered and the brains examined using both standard histology and immunocyto chemistry. The slaughtered BSE suspect animals are destroyed and buried in situ. Full market value is paid by the GOI in compensation. If BSE is confirmed, the entire herd is depopulated and the GOI compensates at full market value for all animals. These herds are slaughtered in a dedicated slaughter plant. The carcasses are rendered into meat and bone meat at one dedicated rendering plant and the resulting meal is incinerated.
Brain sections of all the adult animals are tested for BSE and in all cases the progeny of the affected animals and birth cohorts of the affected animal are traced, purchased at market value, slaughtered, destroyed and rendered in the same manner as the depopulated herds.
The skull, brain, eyes, tonsils and spinal cord of cattle over 12 months and of sheep (and goats) with one permanent incisor tooth (i.e. also aged over 12 months as well as the spleen of sheep and goats) are designated as Specified Risk Material and are excluded from the human food and animal feed chains. The materials are isolated at time of slaughter, rendered and incinerated.
The use of mammalian meat and bone meal is strictly controlled so as to eliminate the possibility of cross- contamination of ruminant animal feed. DAF license manufacturing premises of mammalian meat and bone meal. These premises must maintain strict records of production and sale of the meals, as well as a record of purchasers. All purchasers of mammalian meat and bone meal must have a license. Manufacturers of feeding stuffs for non-ruminant animals in which mammalian meat and bone meal is incorporated must be licensed and have a license to hold such meal. In addition, all mills involved in the manufacture of animal feeding stuffs are under the full time supervision of DAF Inspectors.
COMTEX Newswire Thu, Feb 18, 1999The Spongiform Encephalopathy Advisory Committee (SEAC) met on 11 January 1999. A summary of the meeting is published today in line with recommendations of the SEAC review (published September 1997). The Committee hold press briefings when these summaries are published and the Chairman, Professor Sir John Pattison, hosted today's briefing.
PUBLIC SUMMARY OF COMMITTEE MEETING - 11 JANUARY 1999
The Spongiform Encephalopathy Advisory Committee (SEAC) met at the offices of the Ministry of Agriculture, Fisheries and Food, Tolworth on 11 January 1999. The Committee conducted its regular review of research findings and epidemiological information on BSE and vCJD. The Committee noted that the total number of vCJD cases in the UK was 35. The number of cases of BSE continues to decline in line with predictions about the decay in the epidemic. [Odd, 38 cases are acknowledged at the official DoH home page as of this date -- webmaster]
The Committee had been asked to consider the potential use of Pentosan Polysulphate as a prophylactic against vCJD. Dr. Stephen Dealler attended the Committee, made a presentation and took part in the discussion.
Following this the Committee has provided advice to Ministers and a copy is attached. The Committee had been asked by the Chief Medical Officer of England to consider the risk associated with cheek meat for human consumption removed in Northern Ireland from bovine heads imported from the Republic of Ireland. They noted that a decision of the courts in Northern Ireland meant that the importation of such bovine heads by one specific company for the removal of cheek meat for human consumption had now been permitted pending the outcome of an appeal against this decision to the European Court of Justice.
The Committee considered that it would be preferable that cheek meat imported into the UK came only from animals from countries which have no cases of BSE and that bovine heads from which cheek meat was removed within the borders of the UK also came only from such countries. However SEAC recognised that imports are controlled by EU law. With respect to UK cattle over six months old the Committee reaffirmed its advice that the whole head, other than the tongue, should continue to be treated as specified risk material (SRM). The Chairman of the Committee has written to the Chief Medical Officer of England summarising these discussions and conclusions.
The Committee considered a report from Det Norske Veritas (DNV) on the Assessment of the Risk of Exposure to vCJD Infectivity in Blood and Blood Products. The Committee agreed that because of the many uncertainties preparation of this Report had been a demanding task for DNV and it was difficult to draw any clear conclusions. The Report provided a great deal of useful background information on the sourcing, processing and use of human blood and blood products. The Committee welcomed the intention to publish the report and suggested one or two minor revisions. The Committee saw no reason to revise its earlier precautionary advice to Ministers recommending leucodepletion of blood destined for transfusion.
The Committee, in common with other food safety Advisory Committees, had been asked for its comments in relation to the proposal for an overall framework for the handling of risk analysis, risk management and risk communication across a range of food and food safety issues. The Committee had a preliminary discussion but decided to postpone further discussion until after the BSE Inquiry had reported so that its findings could be taken into account.
PA News Tue, Feb 16, 1999 by Bob Roberts, Political CorrespondentThe Government's Chief Scientific Adviser today said there was "not much of a case" for keeping the beef-on-the-bone ban. Sir Robert May, who works at the Department of Trade and Industry, called the imposing of the ban "a mixture, in my view, of a political and scientific decision". He told BBC Radio 4's Today programme: "On purely scientific grounds I personally don't see much point in banning beef on the bone, but it has to be seen in a wider context."
Asked if he would have advised ministers to lift the ban, he said: "No, I would have said on the purely scientific argument there is, in my view, not much of a case for it. "But you have to see it in a much wider context of the past history, particularly in Europe."
There was hope earlier this month that Agriculture Minister Nick brown would lift the ban imposed shortly after labour came into power. However, Mr Brown announced that the ban will stay or at least six more months, when it will be reviewed again.
Shadow Trade and Industry Secretary John Redwood said the beef on the bone ban and the Government's refusal to consider a moratorium on the growing of genetically modified (GM) crops showed the inconsistency of its approach. "It shows the humbug of it ... You don't even need to label beef on the bone, yet on this other very sensitive issue the Government won't even take the necessary steps to give us proper labelling."
The National Farmers' Union today said its members would be concerned at the comments made by the Chief Scientific Adviser. An NFU spokesman said: "We have always said that, based on the scientific evidence available and the minute risk from beef-on-the-bone, consumers should have the freedom to choose whether they eat it or not. "Whether or not the decision is scientific or political the fact is that the ban has not been lifted yet. In term of our members this may cause concern but to a certain extent it doesn't matter what the reason is."
Meanwhile, a leading Blairite think-tank will claim tonight that the beef-on-the-bone ban may have been motivated as much by the demands of Europe after the BSE-crisis as by concern for human health. Perri 6, director of policy and research at Demos, will scrutinise the regulation of public health and safety risks from food in light of the recent debate on genetically modified (GM) foods at a London lecture later today.
Mr 6 is set to take issue with the Government's beef-on-the-bone ban and voice his suspicions about the true motives for its introduction. He said today: "Such evidence as the Government scientists offered might have justified a paternalistic health warning or the public information for consumers to make up their own minds, but not a paternalistic ban."
The lecture will also focus on the controversial issue of GM foods. Mr 6 said that in his opinion a lot of "pseudo-science" was being peddled by those involved in the debate and added: "No one has ever come up with a single case of actual harm to human health from any of the mainstream GM foods in the supermarkets. "There is no possible justification for politicians claiming to know better than I or any other shopper or diner does what kind of food we want to eat and banning things that we may well want. "That is paternalism too far, whatever the panics about the supposed fragility of nature."
Labour's Dr George Turner, MP for the rural constituency of Norfolk North West, called the Chief Scientific Adviser's remarks a "one-liner". He said the ban on beef on the bone remained in place because of health fears. "It was the Chief Medical Officer's advice that stymied it." Dr Turner said the Government approach to beef on the bone and its refusal to impose a moratorium on GM foods was "entirely" consistent. "If the Chief Medical Officer was coming close to hinting that there was a danger to the public, I am confident that there would be immediate action from the Government."
Meanwhile, the Tories stepped up the pressure on the Government over the lifting of the export ban on beef off the bone. Shadow Agriculture Spokesman Jim Paice demanded clarification of the Government's position after Deputy Agriculture Minister Jeff Rooker said it would be "premature" to ask for applications from abattoirs wanting to be dedicated processors until the European Commission carried out its inspection.
"It is time the minister came clean on the lifting of the export ban," Mr Paice said. "We need to be told precisely what still needs to be done to meet the Commission's requirements and when the invitation will be issued. "It does seem extraordinary that decisions on abattoirs will be after the inspection - does that mean a second inspection will be necessary?" Cabinet Office minister Jack Cunningham, who was responsible for imposing the beef-on-the-bone ban while Agriculture Minister, said today that GM food was a "totally different" issue.
He told BBC Radio 2's Jimmy Young Show: "We knew there was a clear risk, a real risk of BSE-infectivity getting into the food chain. We were given clear advice about that from the Spongiform Encephalopathy Advisory Committee and separately from the Government's Chief Medical Officer. He clearly believed it would not be right to knowingly allow BSE infectivity into the food chain." Mr Cunningham added: "We already knew at that point that more than 20 people had died from new variant Creutzfeldt Jakob Disease and sadly, and tragically, people are still dying from it and I regret to say more will."
But he said that no such scientific evidence was available to condemn GM crops. "That is totally different from the situation with GMs. We've got no such advice from our scientific advisers and no similar advice from the Chief Medical Officer and no evidence of any medical risks involved. "The two things are simply very different."
Mr Cunningham said that, like the Prime Minister, he had no qualms about eating GM products and said he could see no reason for a moratorium on GM crops. "In terms of new licences and new products we effectively have had a moratorium since the Government came into office. We have not issued any new licences. What would a moratorium do that we've not been able to do in the last two years? We would learn nothing new from a moratorium."
Mar 6, 1999 By Tim Moynihan, PA NewsMore than a quarter of butchers across Britain are selling banned beef-on-the-bone, according to a survey published today. The Daily Mail bought or ordered a total of 54 T-bone steaks, 32 ribs of beef and 14 oxtails from 68 of the 250 small butchers approached, it said. Many shops are using loopholes in the law to sell the banned cuts, it added.
The issue is high on the political agenda after the Government suffered the embarrassment of the Prince of Wales being served beef on the bone during a visit to the Celtic Manor Hotel in Gwent. Under the Beef Bones Regulations, introduced in the wake of the BSE crisis in November 1997, anyone selling T-bone steaks, beef ribs or oxtail is liable to prosecution.
Butchers are finding ingenious ways of dodging the ban, the newspaper said. Shoppers who say they are caterers can get served, while some outlets sell expensive joints as dog food, it added.
The newspaper's reporters visited outlets in Hampshire, Kent, Surrey, the west of England, Cambridgeshire, London, Birmingham, Middlesbrough, Sheffield, Cardiff, Aberdeen and Glasgow. The greatest "success rate" came in Hampshire where 10 butchers sold banned cuts, it said. Shops in Cardiff and Birmingham were the most careful to check they were not undercover council officials.
And butchers as far apart as Aberdeen and Gloucestershire used the ruse of selling the beef as pet food, one joking `You must think a lot of that dog' as he handed over a 25 pound rib joint, the newspaper said.
Reuters World Report Thu, Feb 25, 1999Surgery can increase a person's risk of getting Creutzfeldt-Jakob disease (CJD), the fatal brain-wasting disorder, Australian doctors said on Friday. In a report in The Lancet medical journal, doctors at the University of Melbourne said a study of 241 cases of sporadic CJD in Australia between 1990 and 1993 showed a link between the disease and various surgical procedures.
"We found a range of surgical treatments were associated with an increased risk of sporadic CJD. Two previous case-controlled studies...found the risk of CJD was associated with hospital-related therapy," Dr S Collins and his colleagues said in the study.
The researchers compared the medical history of the 241 confirmed and suspected CJD victims with 784 healthy volunteers. The study was limited to cases of sporadic CJD, a strain of the brain disorder that occurs in one in a million people a year and has an incubation period of up to 30 years.
The researchers said the results could have implications for new variant CJD (nvCJD) which infects much younger people. British scientists have linked nvCJD to eating beef contaminated with bovine spongiform encephalopathy (BSE) or mad cow disease. So far 35 people have died in Britain from nvCJD.
The Australian study showed the more operations a person had, the greater the risk of getting CJD. The greatest risk was for people who had had three surgical procedures. They found no link with CJD and blood transfusions, organ transplants or major dental work but said living or working on a farm or with livestock for more than 10 years was a risk factor.
"We believe our findings should reinforce the heightened vigilance about infection control at all levels of care in hospital settings," the researchers added.
Earlier this month, scientists in Scotland said sterilising surgical instruments could help spread CJD. Increasing the temperature of the steriliser actually made it harder to destroy the CJD prions, rogue brain proteins that are the infectious agent for the disease. They recommended using disposal surgical instruments.
February 23, 1999 New York Times By SANDRA BLAKESLEEAs a 30-year-old deer hunter lies dying at his home near Salt Lake City, consumer advocates and Government regulators are squabbling over a terrifying question that cannot be answered to anyone's satisfaction: Is it possible to contract a version of mad cow disease from eating deer or elk?
Mad cow disease appeared in British cattle in the mid-1980's and caused an epidemic that left the brains of infected animals spongy and riddled with gum-like strings. Eventually, the British Government ordered the destruction of more than four million animals. At least 34 young people in Britain contracted a human form of the fatal disease, possibly from eating infected beef or from coming into contact with products made from sick cows.
Nothing similar has turned up in American beef, although experts believe one in a million cows will develop the disease spontaneously.
Animal feeding practices have been revised to reduce chances of transmission. But a similar disease has been seen in sheep and mink, and people are now worried about a version of mad cow disease endemic in deer and elk in parts of Colorado and Wyoming, raising the possibility that hunters who eat infected animals may similarly develop a human form of the deer and elk malady, called chronic wasting disease.
The cow, elk, deer and human diseases belong to a family of disorders called transmissible spongiform encephalopathies, or T.S.E. The human form, Creutzfeldt-Jakob disease or C.J.D., occurs in three varieties. Most cases are spontaneous with no known cause. About 10 percent of cases run in families, linked to inherited gene defects. The British cases are called new variant C.J.D.
In all three varieties, the disease agent is believed to be not a virus or bacterium but a mysterious particle called a prion -- a kind of renegade protein that transforms normal proteins into abnormal, indestructible substances that create spongy holes in the brain. Prion diseases have been found in 85 species, passing easily between some animals and not others. When a prion "jumps" species, new T.S.E. diseases are created that can be more or less virulent for reasons no one can explain.
This is the question raised by the deer hunter's case: Does he have a new variant of Creutzfeldt-Jakob disease contracted from deer and elk, and if so, what does it look like?
Health and wildlife officials point out there is no proof that mad deer or elk disease has "jumped" to humans. At the same time, consumer advocates point to the dying hunter, Doug McEwen, whose illness is uncannily similar to that seen in the young victims of mad cow.
According to his wife, Tracie, Mr. McEwen hunted in season, and often ate deer and elk that he bagged. But he never hunted in Colorado or Wyoming, where chronic wasting disease is found. So no one knows if he contracted his brain disease from animals or spontaneously developed the illness destroying his brain.
Moreover, Mr. McEwen was a frequent donor of blood plasma and his plasma was pooled with many blood products and shipped to 21 countries. Blood safety officials here and abroad at first quarantined the blood products but have since let some of them be used.
In part because of the mad cow outbreak in Britain, the United States Food and Drug Administration barred blood banks from accepting donations from people with family members with C.J.D. But given that it is not known if blood or plasma can transmit the disease, and the fact that almost all Americans with the disease have the sporadic form, which tends not to involve the blood, the Public Health Service and food and drug agency changed the nation's blood policy in August.
Now only those people with familial or genetic versions of C.J.D. are prohibited from donating blood, said Dr. Jay Epstein of the Center for Biologics Evaluation and Research at the drug agency.
American public health officials say that chronic wasting disease in deer and elk and Mr. McEwen's plasma donations pose no threat to people. Careful epidemiological surveys have not shown any increase in the type of brain disease afflicting Mr. McEwen and no indication that frequent users of blood products, like hemophiliacs, have a higher incidence of any kind of C.J.D., said Dr. Lawrence Schonberger, an epidemiologist who coordinates surveillance activities for Creutzfeldt-Jakob disease at the Centers for Disease Control and Prevention in Atlanta.
Many people are unconvinced. "The fact that we have a disease in elk and deer at levels equivalent to mad cow disease at the height of the British epidemic is truly alarming," said John Stauber, director of the Center for Media and Democracy, a group that reports on government and industry public relations, and the author of "Mad Cow U.S.A.," a book critical of American health officials. In both cases, an estimated 6 percent of animals carry the infection.
Mr. Stauber and others interested in the disease say they distrust Government estimates, citing, among other things, published reports estimating that 6 to 8 percent of people who are told they have Alzheimer's disease may actually have some form of C.J.D.
"Was nothing learned from the British experience?" asked Dr. Pringle, who maintains an encyclopedic Web page on the subject (www.mad-cow.org). "Why are we repeating the gamble they took?" British officials for years adamantly denied the cow disease was any threat to humans, he said.
Mr. McEwen, a territory manager of a groceries firm who lives in Kaysville, Utah, first showed symptoms in June when he forgot how to spell his wife's name and could no longer do simple arithmetic. His condition worsened rapidly; by the end of the summer he was forced to quit his job. Neurologists carried out scores of tests, including brain scans and spinal taps, to no avail, until Nov. 24, when they finally took a brain biopsy. The next day, Mr. McEwen was given a diagnosis of C.J.D.
Creutzfeldt-Jakob disease strikes one in a million people over age 50, said Dr. Michael Hansen, a scientist who closely follows the issue for Consumer's Union. The disease strikes fewer than one in a billion people worldwide at Mr. McEwen's age, 30. Moreover, in Mr. McEwen's case, the disease has moved with astounding rapidity, leaving him near death, unable to recognize his two young daughters or his wife.
Alarmed by Mr. McEwen's age and the speed of his illness, state health officials sent a brain tissue sample to Dr. Pierluigi Gambetti, an expert on prion diseases at Case Western Reserve U
niversity in Cleveland. Dr. Gambetti ruled out most known causes of C.J.D. Mr. McEwen never received transplanted tissues that might have been infected with abnormal prions. His disease was not inherited and it definitely did not come from cattle. The diagnosis: sporadic C.J.D., meaning no known cause. Cases like that are rare but not unknown, Dr. Gambetti said.
But Dr. Pringle and others do not accept this diagnosis as final. They point out that no one knows what chronic wasting disease would look like in a human, and tests to determine the nature of such a disease have not been done.
All mammals have prion proteins whose structures vary by just a few building blocks called amino acids. The difference between a cow and a human prion might be eight of these building blocks out of hundreds. But when the abnormal cow prion co-opts the normal human prion, a new abnormal human prion -- and a new disease -- is formed.
It looks exactly like a C.J.D.-related human prion but it can be more insidious. If the new variety of human prion is injected into a cat, yet another disease can be created. It may be more infectious or less infectious in the cat. Such experiments in which the infectious prion of one species is "passaged" into another species is a standard test for sorting out various T.S.E.'s.
"There are many imponderables in these experiments," said Dr. Byron Caughey, a prion expert at the National Institute of Health Rocky Mountain Laboratory in Hamilton, Mont. "One prion is an infectious unit large enough to give you the disease. But it can be terribly inefficient going across species. A person could take in a billion infectious units from a deer or elk and never get sick in his lifetime," he said.
Dr. Schonberger said that there were no plans to carry out interspecies tests on Mr. McEwen's brain tissue because it is clear that he has a natural human form of the disease and because there is no increase of C.J.D. where deer and elk hunting occurs.
According to wildlife officials, chronic wasting disease affects about 5 percent of the deer and 1 percent of the elk found in a small area in northeastern Colorado and southern Wyoming. Sick animals drool excessively, stagger around and lose weight before dying. Hunters in several states are required to turn in deer and elk heads so that the brain tissue can be tested. So far, the disease in the wild has not spread beyond Colorado and Wyoming.
Game farms are another story. The disease is found in captive deer and elk herds in three states -- South Dakota, Nebraska and Oklahoma -- and in the Canadian province of Saskatchewan, said Dr. Beth Williams, the nation's leading expert on chronic wasting disease, at the University of Wyoming in Laramie.
The disease was reported in the mid-1960's at the Wildlife Research Station in Fort Collins, Colo., where it eventually wiped out 90 percent of the animals. But before people knew what was happening, many infected animals were sold to game farms or zoos elsewhere for breeding, thus spreading the infection. Ranchers made large profits selling antlers to Asia, where they are used in making herbal remedies and aphrodisiacs.
The disease was first observed in the wild in 1981, Dr. Williams said. No one knows how it spreads. The infectious prion may be shed in saliva, feces or placenta and if wild animals come across downed fences, they might step on contaminated ground. There is new evidence that the prion may be concentrated in inflamed skin cells, suggesting that the disease could be spread by scratching posts or trees in the wild.
But Dr. Mike Miller, a veterinarian with the Colorado Department of Wildlife who is familiar with the problem, said thousands of people had consumed deer and elk meat and field dressed hundreds of infected animals in the Fort Collins area over the last 25 years. "We make no secret of where the disease occurs," and leave it up to hunters to decide the risks for themselves, he said, although hunters are advised to wear gloves when cutting up animals and to avoid brain and spinal cord tissue.
But a deeper reason to worry is the diabolical nature of the infectious prion particle. It seemingly cannot be destroyed. When medical instruments contaminated with prions are boiled at high temperatures for 30 minutes, the prions remain infectious -- and have passed the infection from person to person. When infected materials are incinerated, the ash contains prions, which remain infectious.
This problem is highly relevant to Mrs. McEwen, who has learned that a local funeral home will not embalm her husband if an autopsy, exposing brain tissue, is performed. Several prion laboratories want her to donate her husband's brain to them exclusively, said Mel Steiger, also from Salt Lake City, whose wife died last spring from C.J.D. and who is now helping Mrs. McEwen. "She has not decided what to do," he said.
Meanwhile, Federal officials ar>