How close is mad cow disease, or bovine spongiform encephalopathy (BSE), to the United States? Close enough to cause a wave of panic about all imported beef-based products -- including vaccines, medicines, herbal supplements, and cosmetics that may include animal organs or be gelatin-based. (And of course the current outbreak of foot and mouth disease, which doesn't hurt humans but is devastating to animals and is spreading like wildfire in Europe, only adds to the hype.) Close enough for the United States to risk a trade war with Brazil by banning Brazilian beef for a couple of weeks. So close that researchers like Dr. Stanley Prusiner have been saying since 1996 that BSE, and quite possibly the disease it causes in humans, varient-Creutzfeldt-Jakob disease (vCJD), is already here.
Should we buy it? Perhaps. Dr. Prusiner, after all, is the scientist who discovered the prion, the infectious agent of both BSE and vCJD. He won a Nobel Prize in medicine for his work. If he says we're in danger, then maybe we are.
Prion disease in general has been chronicled since the Fifties, when a cannibalistic tribe in Papua New Guinea was found to be harboring and passing kuru, a prion disease they got from eating one another's brains. In the United States prion diseases in mammals were noticed beginning in the Sixties. The New York Times correctly notes that, "At various times, 45 states have had sheep that are infected with scrapie, another malady related to mad cow disease." In the Midwest eleven farms have been found to be housing mad cow-contaminated mink, which were fed domestic "downer" cows -- cattle that died from unknown causes and were not tested before being ground up for mink chow. Scientists also are seeing a "slow" epidemic in wild deer and elk; animals in at least six Western states including Colorado, Wyoming, and Nebraska, have been diagnosed with a prion disease called Chronic Wasting Disorder (CWD). Recently a young hunter in Utah and another in Oklahoma, both of whom were believed to have eaten contaminated mad deer meat, died of a similar vCJD disorder. Meanwhile domestic deer-and-elk game farms have been found to be contaminated with CWD.
Those are the facts. Much of the rest is theory, because scientists simply don't know how much of an infectious dose needs to be consumed, what the incubation period is, and how many cattle or people may already have been infected. And they may not know for many, many years. Consider that kuru takes 40 years to incubate. Consider that kuru, which popular medicine says has been eradicated, still is thought to be alive and kicking, so to speak.
One of the theories put to rest is that there is a so-called species barrier that will prevent the spread of BSE from cattle to humans. Obviously wrong, though so far the numbers seem low: about 80 people infected from an original pool of 180,000 infected cattle. Perhaps, researchers are musing, genetic makeup presupposes some people to be more susceptible to BSE-infected tissues. (Immune systems have nothing to do with it, since the prions are not recognized as intruders or attacked by blood cells.) The Official Mad Cow Disease Website posts an article that proposes a scarier scenario: "If BSE crosses to vCJD only with great difficulty, then vCJD might spread quite easily through, say, blood transfusions or maternally -- so any “species barrier' quickly loses its comfort value."
Another theory is that the United States is safe because we have prohibited the import of British beef since the Eighties, and that Food and Drug Administration (FDA) regulations, officially adopted in 1997, have required companies to label meat-and-bone meal (MBM) products with "Do not feed to ruminants." Call us hypocrites. Although the United States officially has blasted Britain for delaying telling the world about its BSE epidemic, we have no more followed up on regulating feed manufacturers than they have. The FDA recently announced that out of 180 cattle-rendering companies, about 25 percent did not label properly or keep animal carcasses and remains separate and distinct. Out of 347 FDA-licensed feed mills, another quarter was found to be in the same violations. Of about 1600 smaller feed mills that are too miniscule for licensing, The New York Times says that a whopping 40 percent were failing to follow guidelines. The paper also estimates there are about 5000 more unlicensed feed mills that thus far have escaped inspection.
Hence the Texas feed lot quarantine. The MBM-contaminated feed, according to an FDA press release, was fed to cattle after "human error." Though the cattle, after testing, were found to be at very low risk -- the 600-pound animals each ate about a quarter-ounce of the feed, which itself is presumed to have been made from BSE-free carcasses -- we can only hope their carcasses don't wind up in our pets' food. Yes, there have been documented cases of house domestics dying from prion disease: 85 cats since 1990 and 19 dogs since 1992.
Zoos also are at risk. Among the spongiform encephalopathy (SE)-infected animals found in zoos -- including cheetahs, lions, ocelots, and tigers -- pumas are of special significance, since they are closely related to the mountain lions of the American West that have been feeding on CWD-infected deer and elk. To date most zoos still are failing to conduct prion tests on dead animals. Samples would be relatively easy to freeze and even simpler to read, but zookeepers cite expense: It currently costs about $1500 to evaluate a brain for SE. In an odder, economically based case scenario, the meat from bullfights, traditionally sold after the bull has been slaughtered (sorry, fought to the death) is now being incinerated. Spanish officials say they can't afford to test the carcasses, as it would cost the nation, where BSE recently was discovered, more than it would gain in revenue.
Nor is the FDA policing the pharmaceutical companies with any real consistency. Inspectors discovered only last year that five of the world's largest drug companies were still using cattle-based materials (blood, fetal calf serum, and beef broth) from banned countries to make vaccines, and have been for the past eight years. Of the nine vaccines that have included animal byproducts from nations known to be infected, four of those -- polio, diptheria, tetanus, and anthrax (distributed to soldiers serving in the Persian Gulf) -- have been widely distributed to Americans. FDA officials, however, maintain that vaccines are safe, estimating the odds of contracting vCJD from a vaccination at one in 40 million to one in 40 billion. You'd probably have a better chance of winning the lottery.
In their own defense, the drug companies say the FDA never issued clear guidelines; rather, the agency "suggested" the companies stop using purportedly dangerous materials. In addition such materials often are used in drugs as well as vaccines, but the FDA cannot legally release a list of those drugs. Byproducts like gelatin from the hooves of cattle are common ingredients, however, as well as things such as calf lungs used to make surfactants, a breathing supplement for premature infants.
As far as herbal and dietary supplements go, the FDA has no rules for their manufacture, so byproducts from BSE-infected countries could legally be brought into the United States. Supplements often contain the very organs researchers say are the most dangerous: brains, pituitary gland, thymus. Taking something to increase your energy? Better check for adrenal extract, my friend. That herbal supplement really working on your allergies? Well, powdered spleen is known to help keep those sinuses open.
Obviously such laxness is cause for concern and already American consumers are vetoing cosmetics made in BSE-infected European countries, especially lipsticks, which could be ingested. Although species barriers help to inhibit the spread of BSE from cattle to humans -- but obviously not completely -- it has been proposed that the prions could travel from human to human much more easily.
Beginning February 28, therefore, bans on blood donors who have lived in Europe have been in effect, and blood centers within the United States have about six weeks to comply with new criteria; the deferral is expected to cause a shortfall of 285,000 units of blood annually.
As research continues on those who have died from vCJD, we should probably expect more testing and more bans. In England a newborn who obviously had never eaten meat was found to have vCJD. Tests conducted on her mother, who had been exhibiting neurological symptoms before she even became pregnant, were vCJD-positive; conclusions were that vCJD could cross the placenta. Now Austria is testing breast milk to see if prions can be transmitted this way.
In the United States, at the National Prion Disease Pathology Surveillance Center, director and neuropathologist Dr. Pieluigi Gambetti examines about 40 percent of the naturally occurring Creutzfeldt-Jakob disease cases (the classical rather than variant form of spongiform encephalopathy). So far, he has not discovered any vCJD, but says he is not seeing nearly all the autopsies he should.
Economically speaking, Americans have not yet translated generalized fear into a stock-market stampede. If confidence in domestic beef begins to falter, the consequences will no doubt be seen in the food and agribusiness stocks. McDonald's, Burger King, and the Sara Lee Corporation have all seen their sales fall off in Europe, and quarterly profits might show some serious declines.
As far as Europe goes, farmers are suffering monstrously. Supply so exceeds demand for beef in France that the government is killing 10,000 healthy heads per week in addition to infected animals. Riots have occurred, with farmers demanding additional Mad Cow Aid. In some countries farmers are being compensated by the governments, which in turn are losing billions. Incineration fees have become so prohibitive that carcasses are being frozen to be cremated at a later date. All possibilities that could become reality in the United States, where, some are saying, the cattle industry is about as safe as houses -- in a tornado.
Next week: Political implications worldwide and locally, Britain takes another hit with a resurgence of foot and mouth disease, and how you can protect yourself.
