Experts to flesh out facts about mad-cow disease

Insight on the News, Dec 9, 1996 by John Elvin

The recent outbreak of bovine spongiform encephalopathy in Great Britain has caused panic in Europe and concern in the United States. With the future of beef at stake, experts will gather in Washington.

Hard on the heels of further scientific evidence linking mad-cow disease and a similar fatal illness in humans, experts from the United States, Great Britain and Europe will gather in Washington in mid-December to discuss rational policy approaches that could help calm public fears. The adjective "mad cow" is applied because infected cattle have been known to become aggressive prior to death, though they just as often are standoffish. They twitch and sometimes are strangely. Eventually they collapse and die.

The baffling disease, formally known as bovine spongiform encephalopathy, or BSE, has caused near panic among beef eaters around the world and pushed Britain's cattle market into chaos. Other countries, including the United States, have ordered the slaughter of cattle of British origin and are developing other measures to protect their publics against the wretched disease and its awful implications for humans.

Georgetown University will be the site of the December forum, titled "Generating Rational Policy in the Face of Public Fears." Among a veritable Who's Who of speakers who have researched mad-cow disease will be several scientists who have contributed to the very little presently known about BSE. Among the speakers will be John Collinge of the Imperial College of Medicine at St. Mary's Hospital in London. Collinge's recently announced studies concluding the probability of cross-species transfer of BSE have reignited controversies between those predicting an epidemic - and therefore demanding prompt, radical remedies - and those who maintain that measures are adequate to eradicate the disease within a few years. Though not, it seems, totally beyond doubt, Collinge's evidence further confirms the strong suspicion that consumption of BSE-infected cattle products causes a variant of the deadly Creutzfeldt-Jakob disease, or CJD, in humans.

As in the case with BSE in cattle, CJD in humans reduces the brain to a spongy mass, in its course causing dementia, loss of coordination and other degenerative symptoms. Tests for the disease are being developed, but to date the only sure diagnosis is through an autopsy.

In a paper published in the science journal Nature, Collinge and his research team concluded that the disease probably crosses "the species barrier," a natural blockage that prevents some disease from being spread from one species to another. An American expert on the disease, Michael Harrington of the California Institute of Technology, said the finding "changes the nature of the debate" in that it provides the first direct evidence" of a link.

Previous suggestions of such a link by scientists working with the British government provoked the wrath of the beef industry as well as British farmers. The mad-cow scare has come near to being the ruination of the $7 billion backbone of the British economy, as some 20 countries have banned imports of beef from the United Kingdom. British Agriculture Secretary Douglass Hogg tried to assuage importers' fears, announcing that all cows known to have the disease would be slaughtered. The current plan involves culling (that is to say executing) 25,000 cows per week, but implementation has been slow - in part due to hopeful reports of a test developed in the United States to spot the disease prior to butchery.

In truth, hysteria might not be too extreme a term to describe the way the disease is being dealt with in Britain, even among scientists. There are those who urge caution in evaluating the cause of BSE and the best methods for its eradication, but the headline-grabbers, such as microbiologist and best-selling author Stephen Dealler, claim that by 2001 most adult British meat eaters will have consumed a fatal dose of BSE-infected meat.

The British governments spongiform encephalopathy advisory committee has not offered any great comfort in agreeing with predictions that an epidemic could result - on the order of the current AIDS crisis. Subsequent communiques from the group indicated that "a number of interacting uncertainties" make any predictions on the matter impossible. Professor John Pattison, chairman of the advisory committee, added as an aside to the London Sunday Telegraph, "Most people believe that the scale of the AIDS epidemic is greater than it really is."

One of the difficulties in assessing the nature and extent of the human variant of the disease is its lengthy incubation period. Some studies put it at 15 years or more, with five years said to be a minimum and a 40-year maximum.

No deaths due to BSE have been reported in the United States, but scientific, medical and cattle-industry reaction to the possibility runs the afore-mentioned gamut from dire forecasts to near calm.

The Centers for Disease Control and Prevention, or CDC, has been actively monitoring a number of U.S. locales for any appearance of the CJD variant in humans, says spokesman Tom Skinner. Skinner provides a recent report stating that, based on limited surveillance, there is "no evidence of an outbreak of the variant of CJD" in the United States.