Mad-cow Disease May Harm Humans After All

Britain Concedes People Can Contract Fatal Illness

March 21, 1996|By New York Times News Service.

LONDON — Britain's government conceded Wednesday for the first time that there may be a link between mad-cow disease, a deadly neurological affliction of cattle in Britain, and a similar fatal brain disease in humans.

Apparently mindful of an ever-widening scare among British consumers that British beef might be unsafe, Health Secretary Stephen Dorrell emphasized that there is "no scientific proof" that the disease in cows, formally known as bovine spongiform encephalopathy, can be transmitted to humans through beef.

But then he told a stunned House of Commons that a government science advisory panel had linked an unusual outbreak of the human disorder, Creutzfeldt-Jakob Disease, to exposure to the cattle disease.

Exposure to the disease through the consumption of beef years ago is "the most likely explanation" for an apparently new variant of Creutzfeldt-Jakob Disease, which was discovered in 10 people under the age of 42, including some in their teens, Dorrell said. Normally the disease, which is rare, strikes the middle-aged and elderly.

The incidence of Creutzfeldt-Jakob Disease is small in Britain but increasing. It nearly doubled between 1990 and 1994, reaching 55 cases two years ago. Meanwhile, the rate of mad-cow disease has fallen, after reaching a peak of 900 to 1,000 cases a week in 1992-93. There were between 280 and 300 cases a week reported in January.

Wednesday's statement is an embarrassing about-face for the government. Since 1990, when concern first arose, it had insisted there was no link between the two diseases or that, even if one were established, measures were in place to keep the parts of cattle carcasses likely to cause infection out of the human food chain.

To drive the point home that British beef was "perfectly safe," then-Agriculture Minister John Gummer went on television and fed a hamburger to his four-year-old daughter, Cordelia.

Now the government is acknowledging that the link may in fact exist, while asserting that, as Dorrell put it, "the risk from eating beef is now likely to be extremely small."

It is expected that the shift will be another blow to Britain's $7.5-billion beef industry, which has seen a 12 percent decline in sales over the last five years. Last year, Germany, a European Union trading partner, tried unsuccessfully to ban the import of British beef.

(The U.S. Department of Agriculture said that no processed beef or cattle have been imported into this country from Britain since 1989 and that mad-cow disease has not been detected in the U.S. The agency said it is reviewing current policies and regulations regarding mad-cow disease.)

Signs that the scare is far from over abound. A headline in Wednesday's Daily Mirror said: "Mad Cow Can Kill You." The story said some experts believe that more than one million infected animals may have already been consumed in Britain.

The fears are exacerbated because there is an incubation period of between 10 and 40 years for Creutzfeldt-Jakob Disease, raising the possibility that some people may have been infected by it but have not yet begun to show symptoms.

Bovine spongiform encephalopathy was only discovered in 1986. While both it and Creutzfeldt-Jakob Disease remain something of a biological enigma, the two were thought to be related because they have the same pathology. Both attack and destroy the brain in the same way, ending in death.

An early theory advanced the idea that a virus or virus-like agent was the cause, but more recently some medical researchers have advanced a theory that relates the diseases to an abnormal protein in the cell membrane, presumably transmitted through the consumption of infected tissue, which sets off a chain reaction that damages other proteins.