By David Minsky
By Jen Mangham
By Bill Wisser
By Laine Doss
By Bill Wisser
By Dana De Greff
By Laine Doss
By Zachary Fagenson
Kimmi is a smart girl. But not because raw quivering cow brains are heavy on the scale of too-gross-for-words. Rather Kimmi was clever enough to avoid the one item on that day's menu that could have killed her.
Cow brains carry mad cow disease. A lot of us sort of vaguely know what that is: You eat cattle that's been contaminated somehow, and it makes you crazy and kills you in the long run. Some of us remember the mad cow panic in Great Britain during the early- to mid-Nineties, and a few of us have been following the news now, which largely reports on the development of cases in France and other parts of Europe.
More than 150 cases of mad cow disease have been reported in French cattle for the year 2000, with another 29 so far in 2001. Ireland and Portugal have similar numbers. Britain leads the pack -- or herd -- with 1344 reported in 2000 and 27 in 2001. (In total 180,802 cows have been diagnosed since 1987; 177,706 have been found in Great Britain alone.) Germany, Denmark, Italy, and Spain have all seen cases develop within the past three years, where previously there were none. Better screening practices are being cited for the seemingly astronomic increase. But the American public generally considers mad cow disease, as Norman Van Aken, chef-proprietor of Norman's, notes, a "European problem."
He's right. That's how blithe Americans think of mad cow. But in fact it's not just a European problem any longer. It's a world problem. And as diagnoses of new cases in cattle spring up in Asian nations ranging from Malaysia to Thailand, it becomes clear that every country is at risk. The United Nations Food and Agriculture Organization (FAO) has announced that "at least 100 countries are at risk from mad cow disease because they imported cattle or MBM [meat-and-bone meal] in the late 1980s and 1990s."
Indeed England, where the disease originated, exported cattle remains to be used as food until just a few years ago, despite banning such a practice concerning its own cattle in 1986. Now Lebanon and South Korea, both nations that have imported live cattle or animal feed from Great Britain before 1996, are experiencing declines in the meat and dairy industries -- declines, it might be noted, that are fueled solely by panicked rumors.
Mad cow disease, or bovine spongiform encephalopathy (BSE), is a member of the family of transmissible spongiform encephalophathies (TSE), a group of acquired and occasionally hereditary diseases in humans and animals alike that causes irreversible brain damage and eventually leads to death. In humans the most common TSE, according to the World Health Organization, is Creutzfeldt-Jakob disease (CJD). The infectious agent of BSE, once transmitted to humans, results in what scientists are calling new-variant or variant CJD (vCJD).
The reason why vCJD is so scary is because the infectious agent is not a bacteria, virus, or fungi. It is something called a prion, an abnormal protein that, once it enters the body, acts like a cult leader; other, formerly normal proteins twist and adapt themselves in order to become like the prion. Basically we have no natural defenses against prions, and currently there is no cure or vaccine. There's not even a treatment for symptoms. Prions have no DNA, and yet they can still reproduce; they also survive sterilization techniques, radiation, and alcohol immersion. In short you can't cook mad cow disease away like you can salmonella. You can't freeze it to death like parasites in raw fish. Prions are way too stable for that.
In fact more remains unknown about vCJD than known. The infective dose -- how much one needs to consume in order to develop vCJD -- is a big mystery. The incubation period, also somewhat uncertain, is thought to be long enough that it has not yet been determined just how many people have been affected by the first outbreak in 1995. The disease kills within two years once symptoms appear and has been described as a fast-acting Alzheimer's. Victims first suffer memory loss and inability to reason, then lose motor control. Within six months most of those infected with the disease no longer can walk or feed themselves.
Interestingly what is known is how vCJD was initially transmitted. The cows seem to have acquired the disease via sheep infected with scrapie, another prion disease. Not carnivores by nature, the cattle were fed the remains of infected sheep, and the rest is epidemiologic history. Even so, it was at first assumed that BSE could not cross the bovine-human species barrier. But to date, about 90 people have contracted the disease.
Researchers have discovered that BSE-infected milk and beef will not necessarily cause vCJD. The Website for the University of Illinois at Champaign-Urbana notes that "with the exception of the brain and spinal cord, and more recently, the retina, all tissues and secretions from confirmed BSE cattle have failed to transmit the disease when injected into or fed to mice." In other words the nervous system, of which the retina is really a piece, is the most highly "contagious" cow part. Which makes sense, since the prions attack the nervous system in cows and humans alike. "Theoretically the greatest risk to man would be by direct infection through injection of products derived from bovine brain or lymphoid tissue," the site concludes.