Creutzfeldt-Jakob disease eats holes in your brain and causes you to stagger, twitch, cry out in your sleep, lose control of your bodily functions, go mad and die. The disease may have been hidden in a hamburger you ate in Europe ten years ago, a corneal transplant or your own genetic makeup. It can incubate for anywhere between five and thirty years and will make itself known only when you're within months of death.
Two Denver residents died of CJD--a cousin of mad-cow disease--this year.
And Colorado is the epicenter for another related malady--chronic wasting disease, or CWD--among mule deer and elk. In affected parts of the state, the incidence among deer is between 4 and 6 percent; it is 1 percent in elk. At the height of the mad-cow epidemic in England, the incidence of bovine spongiform encephalopathy, or BSE, in cattle in that country was less than 1 percent.
Last February, Chris Melani, a Longmont hunter, took the head of a deer he'd shot to the Colorado Division of Wildlife for testing. He was told the DOW would contact him within three weeks if the deer had chronic wasting disease. When he heard nothing, he and his family ate some of the meat. He took what was left to a packing plant, where, he says, "It got mixed up with a bunch of other people's deer and made into venison sausage"--ending up on who knows how many dinner plates. Six weeks after turning in the head, Melani learned his deer was among forty that had tested positive for CWD last season. "They said it was okay," he says. "They weren't going to tell anyone else about it."
Although scientists don't know if humans can become ill by eating tainted venison, the encephalopathies do transmit from species to species, and 26 people in England have succumbed to a frightening new variation of Creutzfeldt-Jakob disease that's linked to mad-cow disease.
One of the most common routes for CJD infection is tissue from human cadavers used in surgery. In September, a forty-year-old Denver woman died of CJD. Because the disease generally occurs spontaneously only in the elderly, autopsy tissues were collected and sent away for analysis.
Last month it was determined that this woman had not died of new-variant CJD--that is, that her illness was not connected to eating meat. "It appears that she acquired the disease when she had surgery in Denver in 1992," says Dr. Richard Hoffman, a state epidemiologist with the Colorado Department of Public Health and Environment. During surgery to correct a congenital malformation of the spinal column, a portion of dura mater, tissue taken from the outer covering of the brain, was used to protect part of the woman's central nervous system.
"The material came from a company in Germany," says Hoffman. "In 1992 such material was pooled from several donors--I don't know how many. It will never be possible to prove 100 percent that that was the cause, but the incubation period of six years is about the right length of time for this disease if it's brought on by contaminated tissue."
Between 1987 and 1992, exposure to infected dura mater killed seven people in New Zealand, Britain, Italy and Japan, according to Richard Rhodes's book, Deadly Feasts: The Prion Controversy and the Public's Health. Three Australian women died during the same period because they'd used a hormone called gonadotrophin to counteract infertility. And there have been eighty known deaths worldwide from the use of contaminated human growth hormone.
Creutzfeldt-Jakob claimed a second Denver victim this year, a 78-year-old man. "It's the worst thing there is," says Linda, one of his daughters. "It turns your brain tissue to sponge."
"He'd always been relatively healthy," says a second daughter, who asks to be identified only as Sue. "But six months before this came to a head, we noticed some things. He was becoming forgetful, unable to complete projects he'd done all of his life. We put it down to old age. In February, on a trip, he experienced some dizziness and light-headedness. He came back, and there were other problems. He had trouble walking; his speech was a little slurred; his balance was totally off. We thought perhaps he'd had a stroke, but the tests were negative."
There were other tests: for Lou Gehrig's disease, for Guillain-Barre. But their father's health continued to deteriorate, and when the hospital could offer nothing but custodial care, his family took him home. "In four months," Sue says, "he went from fairly healthy to unable to care for himself whatsoever. He was unable to swallow, and he contracted pneumonia. Less than a week later, he was dead."
At present, the only viable way of identifying Creutzfeldt-Jakob is a brain biopsy, a procedure difficult to perform on a living subject. CJD was diagnosed in this man only after death. On the death certificate, the cause of death is listed as pneumonia.
Because of misdiagnoses like this, health activists say, no one really knows how prevalent CJD is. Although federal officials say instances of CJD have not increased in this country, in most states, including Colorado, CJD is not a reportable disease--one that states are required to document for the Centers for Disease Control. Meanwhile, alternative studies indicate that perhaps 13 percent of patients diagnosed with Alzheimer's are in fact suffering from CJD.
"Sometime, somewhere, someone has to start taking reasonable surveillance seriously and establish a baseline," says Liz Armstrong, who founded CJD Voice, a Web-based support system for the friends and families of CJD victims. "It is only then that anyone can state whether there is an increase, a decrease or no change in the number of CJD cases in the U.S." CJD Voice's membership currently numbers 242, Armstrong says, and often grows by a member a day.
Gloria, a Californian who asked that her last name not be used, knows all about the family of diseases that includes CJD. Her husband died three years ago of the disease.
Ten years ago, right before a planned trip to Israel, her husband had reconstructive surgery on an injured eye. "Right before we left, in his sleep, he would babble and scream and laugh," remembers Gloria. "We went to the doctor, and the doctor kind of laughed and said, 'Don't watch the 11 o'clock news.'" But in Israel, the sleep disturbances continued. "He came to me one night with a flashlight," Gloria says, "and said there were men climbing down from the roof and to be very quiet."
After that, the hallucinations came in droves. "Every once in a while, he would cry and say, 'What's happening to me?'" Gloria says. "At the end of nine months he was in diapers, couldn't walk, didn't know who I was, kept looking for 'Gloria,'" she continues. "I had to pick him up out of bed, dress him. He shook continuously, and he kept rubbing his left blind eye--said it was so itchy. One morning I came out of the shower and he invited me to his bed. He couldn't do anything much. Afterward, he tried to throw me out of the apartment because his wife was going to be coming home. Finally, he went into a coma and died a few days later.
"I worked as a therapist in a day treatment program with schizophrenics and autistic kids," Gloria concludes. "But I have never seen anything like this. Never."
Despite the news from England of human deaths caused by consumption of contaminated beef, federal officials here say there's little cause for alarm. Bovine spongiform encephalopathy has never been detected in U.S. cows, they say, and there has been no confirmed case of new-variant CJD here.
But activists point out that testing has been done on only a tiny percentage of the 70 million or so cows in the United States and that the economic pressure to find nothing wrong is tremendous. In fact, there are indications that some form of BSE does exist in this country: In 1985, large numbers of mink on a Wisconsin ranch began dying of a spongiform encephalopathy; they had been fed meat from fallen dairy cattle. And Stanley Prusiner, who won a Nobel Prize for his work on the origins of CJD, said in 1996 that mad-cow disease had to be present at a low level in the U.S.
The cause of this family of diseases is generally believed to be an agent unlike anything previously known--an errant protein called a prion that manages to multiply uncontrollably in a process like that of crystallization. But although Prusiner won a Nobel Prize for this theory, there are credible researchers who believe the infectious agent will turn out to be viral. This is no abstract argument: Any hope of finding a cure depends on a clear understanding of cause.
The first case of CWD in a Colorado mule deer was discovered in 1967. In 1979 the first two elk succumbed; they had been held in the same area as the afflicted deer. Today the incidence among mule deer in the affected areas of the state is between 4 and 6 percent. In elk, CWD is at less than 1 percent, and the Division of Wildlife no longer requires that elk heads be tested. The disease has been found in northeastern Colorado, in and around Larimer County and concentrated in the area between Fort Collins and Estes Park, according to Todd Malmsbury, DOW spokesman. There is also evidence of CWD in southeast Wyoming, in South Dakota and among captive herds in Alberta, Canada.
CWD does not arise spontaneously in the wild, and no one is sure how the animals became infected. An anonymous Utah rancher offers his opinion on the mad-cow disease Web site (www.mad-cow.org). Deer have always scavenged feeder bins, this rancher says, and have therefore eaten animal renderings in cattle feed, including "not only cow, sheep and all other animal bypass, but also themselves in highway kills and deer and elk dressings from hunter processings commercially done."
The rancher is skeptical about the alleged absence of the disease in U.S. cattle, noting that cows raised for food do not live long enough to manifest BSE. "Let's be real here," the rancher concludes. "If it is ever suspected, no rancher or feeder would lay himself open to having his entire herd culled for BSE at a potential loss of several hundreds to near $1,000 per animal, and neither would the livestock-dependent industries, including pharmaceuticals, cosmetics, soaps and beyond."
Dr. Thomas Pringle, a biochemical geneticist who consults for the Sperling Foundation, believes the disease emerged in Fort Collins thirty years ago, when deer were penned with scrapie-infected sheep. Scrapie is a wasting disease that has affected sheep for at least two centuries; many people believe England's BSE epidemic started after cows there were fed the remains of sick sheep. Since scrapie had existed for so long without harming humans--as far as anyone knew--the British government assumed that BSE was equally harmless. It was a disastrous assumption. "I place the blame squarely on DOW for ever allowing scrapie sheep to be closely quartered with wild game," Pringle says, "for waiting fifteen years to autopsy facility animals suspected of having scrapie, for releasing exposed animals back to the wild, for shipping sick animals to game farms and zoos long after they knew their incompetently managed facilities were contaminated, and for years of inaction and denial over the extent of the epidemic."
Pringle postulates a hypothetical worst-case scenario: "CWD spreads all up and down the Rocky Mountains, affecting many species of ruminants and carnivores. Over time, it then spreads to the rest of the West and to the rest of the country (and continent). It becomes established in domestic ungulates, first on common pastures on public land allotments, then more generally. Feeding, injection and in vitro studies suggest transmissibility to humans, and a new strain of CJD emerges among hunters in Colorado. Ranching interests then push for the systematic slaughter of all large wildlife in North America."
Pringle acknowledges that this X Files-worthy scenario compounds five hypothetical events: "that CWD will spread to other species in the wild in other locales; that it will be experimentally transmittable to sheep and cattle; that significant transmission to livestock occurs under field conditions; that livestock become infectious under short time scales; and that significant oral transmission will consequently occur in humans. I would guess the first is likely but the time scale uncertain," he says, "the second is nearly certain; the third is plausible at some level; the fourth is somewhat doubtful; and the fifth is a real unknown."
"We take a proactive approach," says the DOW's Malmsbury. "We tell people, don't take sick animals, and there are parts of the animal you should not eat--brain tissue, nervous tissue. But meat from wild animals is a health food compared to meat we get from grocery stores. It's literally prescribed by doctors on the Western Slope because it's low in fat and has no preservatives.
"We're not a meat-inspection program," Malmsbury continues. "We're a research program. If we find CWD, we do notify people, but there's no way we can go out and certify every person's animal for every disease, and we cannot notify immediately. There's no evidence to suggest that eating the meat of wild animals is going to be a hazard to human health, and no reason for people not to hunt."
Chris Melani, the Longmont man who shot a deer and ate its meat before finding out that it had CWD, is less confident. "As far as they know, it's not transmittable to cattle and humans," he says, "but you could turn that around and say as far as they know, it is." He adds, "I shot a one-year-old deer, and they say it doesn't affect young deer. When I shot it, it seemed perfectly healthy. Maybe a little stupid, but what do you expect from a little deer?"
For his part, Pringle expects trouble. "It is fair to say that a large-scale experiment is now under way on how efficiently CWD transmits to humans," he says.
"This wasting disease is higher among deer and elk in Colorado than BSE ever was among cows in England," says Jean Halloran, director of the Consumer Policy Institute of the Consumers Union. "It's huge. And I don't see a concerted effort to assess whether this might be a problem for human health."
In 1997, the U.S. Food and Drug Administration came out with regulations forbidding the use of most mammal protein in feed for cows, sheep and goats. But blood, gelatin, milk, and pig and horse protein, as well as food scraped off diners' plates in certain restaurants and institutions, were exempted from the ban, according to Rhodes's book. Animal feed can also include euthanized cats and dogs, mink carcasses and poultry manure. Pet animals can get transmissible spongiform encephalopathies, and so can mink. Deer remains--roadkill and hunters' waste products, including brains and spinal cords--go into pig feed. Although pigs don't seem to get these diseases, they're usually slaughtered before a disease could manifest itself. In turn, pig carcasses are rendered for cattle feed.
"We should have a complete mammal-to-mammal ban," says Halloran. "I'm especially concerned about a new product for feeding calves. Freeze-dried blood. It's not even rendered. I've given up red meat since I've been on this project.
"If you have a taste for red meat," she adds, "my recommendation is to eat it in big chunks. That's better than something like frankfurters. Muscle meat has a very low level of infectivity compared to other parts of animal. It's the nameless organs that you want to avoid."
While Halloran is pushing for better information on CWD and BSE, Armstrong and other activists argue that CJD should be universally reportable. There has been a cluster of CJD cases in Salt Lake City. Mel Steiger, whose wife died of CJD, is spearheading the effort in Utah--with the support of morticians, who are at risk of infection when preparing bodies. "Most of the mortuary equipment cannot be sterilized," says Steiger, "so anyone who works on it and receives a puncture wound is at risk of becoming infected."
The Colorado Department of Public Health and Environment, which is working with the Centers for Disease Control on CJD, reviews the question of which diseases should be reported annually, says Dr. Hoffman. "I don't mind considering the addition of this," he adds. "It makes the statement that the board of health thinks it's a public health concern. I can see some value in sending out the message."
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In August, Dr. John Collinge, professor of neurogenetics at London's Imperial College and one of the topic's foremost experts, delivered a far more pointed message to the London Times: "There seems to be a revisionist view gaining ground in the press not only that the link between bovine spongiform encephalopathy, or 'mad cow disease,' and new-variant CJD is not clearly established, but that the epidemic is likely to be small. In fact, the link is very clearly established and there are going to be a lot more cases. We are still in the dark about how many, but we have to prepare for the worst."
"We don't have a problem of that magnitude," says Halloran, "and we can prevent having one. But we don't seem to be doing it. We're taking half-measures and taking them late."
"What upsets us the most is when we've gone to the medical establishment for answers, there haven't been any," says Sue, remembering her struggle to get help for her father. "And nobody seems to think this is important. It reminds me of AIDS in the Eighties. People didn't want to hear about it. Had we paid more attention then, possibly it wouldn't have mushroomed.