CJD Deaths Rising­
Mad Cow Disease May
Kill 500,000 Britons
Deaths Tied To Mad Cow Disease On The Rise
By Sandra Blakeslee
New York Times, Tuesday (7-25-00)
Deaths from the human form of mad cow disease appear to be increasing, British health officials have reported, but they say it is still unclear whether the increase is the start of an epidemic or merely a statistical blip.
So far this year, 14 Britons have died of the disease. That is as many as died all last year, and five others are known to be dying from the disease, which is always fatal.
If the trend continues and an epidemic is in its early stages, experts estimate that as many as 500,000 Britons could die over the next 30 years from the disease, which is contracted by eating infected beef products.
Even if the numbers begin to fall or hold steady, they said, hundreds or thousands of people are going to die from the disease, called variant Creutzfeldt-Jakob Disease, which literally eats holes in the brains of its victims.
"I am worried about this year's figures," Dr. Roy Anderson, a zoologist from Oxford University who has studied the epidemic, told The Independent, a British newspaper, last week.
Dr. Anderson said Britain was just now seeing the consequences of exposure to the disease in cows in the early 1980's. He said in humans the disease had a "long incubation period, then cases appearing in a trickle."
The rise in deaths now fits that pattern, he said.
"That's what you expect in an epidemic." Other experts said the trend was less certain.
"It's hard to know what the new numbers mean," Dr. Peter Smith, an epidemiologist at the London School of Hygiene and Tropical Medicine, said in a telephone interview. Dr. Smith is acting director of the Spongiform Encephalopathy Advisory Council, which advises the British government on the disease.
Dr. Smith said that the number of cases remained flat for the last four years, and that something now appeared to have been "switched on." Since it first appeared in humans in 1996, a total of 74 people in Britain, 2 in France and 1 in Ireland are dead or dying from the disease, he said.
The increase in deaths this year "is surprising, and it is of some concern," Dr. Smith said.
"But it does not necessarily portend a large epidemic."
The Health Department issues a monthly bulletin on the number of cases, Dr. Smith said. The next bulletin is due on Aug. 7.
Mad cow disease first appeared in the mid-1980's when British cattle began falling ill with a mysterious brain malady.
The epidemic was traced to protein feed supplements infected with brain and nervous tissue extracted from sick cows.
Since then, more than 176,000 cows have died from the disease and 4 million more were destroyed to prevent the disease from further spreading.
But it soon turned out that the infection could spread from cows to humans through eating contaminated beef products, a fact scientifically confirmed only last year.
The transfer to humans was first suspected in 1996, when 10 young people died with spongy holes in their brains. Until then, such symptoms were found only in much older people who died from a form of C.J.D. not related to eating cattle.
But since the disease may have an incubation period of more than 25 years, the question remains how many Britons may be infected and will eventually die from it? Millions of people probably came into contact with infected meat, though it is not clear how many will actually contract the disease, Dr. Smith said.
So far all those infected have possessed a particular genetic trait that apparently predisposed them to the disease. At least 40 percent of the British population shares that trait, which involves a variation of the prion protein, according to experts.
Health officials announced last week that they had identified a probable cluster of cases in Queniborough, a small village about 100 miles north of London. Four young adults from the area have died, apparently from the disease, in the last two years and fifth person, who just turned 25, is near death.
Epidemiologists are combing the village for clues to what the victims had in common and to help them better understand how the disease spreads from cows to people.
Researchers are handing out questionnaires to the village's 2,297 residents asking them what they ate 10 and 15 years ago. They are also investigating 10 local slaughterhouses where cattle parts, including offal, were often turned into specialty meats.
It is possible that a locally slaughtered "mad" cow made its way into sausages eaten by Queniborough's children, said Dr. Philip Monk, who is an expert in communicable diseases at the Leicestershire Health Authority.

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