Mysterious Brain Disease Defies Easy Solution

It appears randomly in about one out of one million people. In the United States that means somewhere over 200 people get it, and die from it, each year. We know that they die because no one can survive it-mortality from the disease is 100%. It is Creutzfeldt-Jakob disease (CJD), among the deadliest, and least understood, of all brain diseases.

Thus far, its impact has been relatively small. Unlike HIV infection, whatever it is that causes the disease has not spread through the masses. Even in the United Kingdom, where public health officials linked the spread of bovine spongiform encephalopathy (BSE)-so-called "mad cow disease"-to a number of reported cases of CJD, there have only been about 20 reported cases.

So is there any reason to panic? And is there any cause to believe that the federal government, especially the U.S. Food and Drug Administration and Department of Agriculture, is not doing enough to assure that the CJD does not become an epidemic so widespread that eating becomes unsafe? The answer, as in so many other situations where scientific discovery cannot keep up with public health, is "it depends."

The ambiguity arises because scientists have still not figured out what exactly causes transmissible spongiform encephalopathies (TSEs). These forms of degenerative brain diseases have been identified over the past several decades in animal populations such as cattle, sheep, mink and squirrels, and in human populations ranging from cannibals in New Guinea to the victims in the UK. TSEs can be spread by using protein derived from infected mammals in veterinary feed, and that if the food supply is not properly insulated, outbreaks of the disease can occur.

In June, therefore, the FDA, after receiving 1,460 formal comments on the issue, and two open public meetings to discuss the most "appropriate course of action," issued its final regulation, which according to a prepared statement, prohibits the use of mammalian protein (with certain exceptions) in the manufacture of animal feeds given to ruminant animals such as cows, sheep and goats." The debate, not surprisingly, surrounds the "certain exceptions," which some groups have termed loopholes in the law that could endanger public health.

According to the FDA, "the final rule allows the use of products believed to pose a minimal risk of BSE transmission. These include blood, blood products, gelatin, milk, milk products, protein derived from swine and equine sources, and inspected meat products which have been offered for human food, and further meat processed for food, such as plate waste from restaurants and other institutions."

But Consumers Union, and other advocacy groups, have challenged the rule, claiming the exceptions leave a breach in the "regulatory firewall" the FDA had promised to construct to protect the food supply. According to a June 4 article in the Washington Post, Michael Hansen, a food safety researcher with the Consumers Union, charged that the "FDA has left the door open for a mad cow-like disease to circulate in the United States by allowing feed derived from mammals to be given to pigs and poultry." Consumers Union has urged the FDA to adopt an outright ban of all animal remains in feed.

The criticism has not moved the FDA to reconsider its stance on the subject. Insisting that there is currently no evidence linking any form of TSE with chickens or pigs, or with the other byproducts exempted from the rule, the FDA has no plans to amend the rule without further evidence of danger.

Lawrence Bachorik, an FDA spokesperson, told Psychiatric Times that the rule, seeks to balance what is scientifically known about the disease against problems an outright ban would create. Prohibiting the use of all remains would create an ecological nightmare, requiring meat processors to find other ways to dispose of mounds of animal byproducts.

"We're a science-based agency and we go where the science allows us to go or says it's appropriate to go," Bachorik said. "If the science changes or if we learn new facts, we certainly will be flexible and do whatever needs to be done to avoid a potential public health problem."

Part of the problem, however, is that the science could end up proving that an overall ban may have been the safest course. In his latest book, Deadly Feasts, Pulitzer Prize-winning author Richard Rhodes describes decades of research into TSEs, including the appearance of the disease in places where it had never before occurred.

Researchers have been able to transmit the disease from one animal species to another by injecting infected brain tissue into test animals. But the FDA has dismissed concerns , claiming they do not replicate real world conditions. "We'd like to see one natural case before we condemn a whole industry," said Stephen F. Sundlof, director of the FDA's Center for Veterinary Medicine in a June Washington Post article.

Meanwhile, alarms about the disease continue to go off around the world. Last month, Canadian Red Cross officials advised hospitals throughout the country that up to 100,000 people may have received blood products from a donor whose father was infected with Creutzfeldt-Jacob disease. Although the donor did not have any signs of the disease, a genetic test revealed he was carrying a mutation associated with inherited forms of the illness.

In October, University of California at San Francisco researcher Stanley B. Prusiner, M.D., received the Nobel Prize in Physiology or Medicine for his discovery of prions, protein particles that his research showed can turn destructive. They are the prime suspects in the transmission of TSEs.