Fear on The Hoof.(spread of mad cow disease)(Brief Article)(Statistical Data Included)

The danger's true extent is anybody's guess, but the concern is spreading around the world. Last week the United Nations Food and Agriculture Organization (FAO) warned that cattle in more than 100 countries may have been exposed to mad-cow disease: bovine spongiform encephalopathy (BSE). Since the mysterious degenerative brain illness was first identified in Britain in 1985, it has killed roughly 180,000 cattle and been blamed for the deaths of more than 80 people. The FAO expressed particular concern about the possible threat of lurking BSE in Eastern Europe, the Mideast and Asia, where Britain exported large quantities of possibly contaminated animal feed after banning its use domestically in 1986.

Epidemiologists fear BSE's final cost may be far higher. They say its incubation period seems to take decades in humans, and it is nearly impossible to detect until its terminal stages. Reputable scientists, extrapolating from data on roughly similar outbreaks of illness, have suggested that the death count from BSE's incurable human form, Creutzfeldt-Jakob disease (CJD), could eventually top 125,000 in Britain alone. Meanwhile, health professionals around the world are debating the risks of infected blood donations and querying the past safety of every kind of cattle-derived product, from baby food and skin creams to polio vaccines and other medicines.

New warnings and worries emerge almost daily. London's press reported last week that blood from a British donor, an undetected CJD victim, had been used to make a vital clotting agent used by hemophiliacs--and that blood products from the same source were shipped to 10 countries around the world, from Brazil to Dubai. British health authorities insist that the risk is utterly conjecture: there is no evidence that the disease can be transmitted in blood. Nevertheless, at blood banks in Australia, the United States and several other countries, donors are automatically rejected if they spent six months or more in Britain during the '80s or early '90s.

The U.S. Food and Drug Administration, similarly nervous, has been urging pharmaceutical manufacturers for the past decade to make sure their vaccines contained no cattle byproducts from anywhere BSE has been detected. Last week The New York Times reported that some international drug firms had disregarded the FDA's requests. Still, the Centers for Disease Control and Prevention insist the danger from the vaccines is minimal.

The big risk is still from eating infected beef. The contagion raced across Britain in the 1980s, when farmers routinely fed their cows on the ground-up remains of cattle carcasses as a cheap protein supplement. Scientists now know that the BSE pathogen is highly infectious. Medical investigators estimate that a single gram of infected meat-and-bone meal (MBM) --a scrap no larger than a peppercorn--is enough to transmit the disease to a healthy cow.

Back in the mid-'80s, though, the disease was a mystery. While the epidemic raged among cattle, British grain dealers exported thousands of tons of potentially infected feed, mostly to Europe. As the Continent's worries grew ...