(Long) NYT article about Mad Cow Disease.
January 26, 1999
Britain Details the Start of Its 'Mad Cow'
Outbreak
By EMILY GREEN
Despite years of increasing worry and worldwide headlines, the British
government has only now gathered the information it needs to figure
out how "mad cow disease" spread through the nation's dairy herds
and apparently cost 35 people their lives.
Late last year, a public inquiry by the government concluded the yearlong
fact-finding phase of a nationwide investigation into the handling of mad cow
disease, more properly known as bovine spongiform encephalopathy, or BSE.
On the same day, an advisory committee of
the U.S. Food and Drug Administration
recommended that the agency consider
banning blood donations from people who
have visited Britain since 1980, just in case
the disease could be spread through the
donations.
Both the recommendation and the British
inquiry have the same aim: prevention. "The
primary object of this inquiry is not to
attribute blame for what occurred," Lord
Justice Nicholas Phillips said as his inquiry
began, "but to identify what went wrong
and why, and to see what lessons can be
learnt."
Colin Blakemore, a professor of physiology at Oxford, called for the
investigation in 1997, when he assumed the presidency of the British
Association for the Advancement of Science. The year before, Blakemore
said: "We must reform the way in which scientific advice is given to and
interpreted by government ministers. Time and time again, inappropriate
assurances to do with human health were made by people with no
qualification to make them."
The British panel will sort through the information it has gathered and issue
conclusions and recommendations in June. In the process, it is producing a
medical detective story of unusual proportions. Testimony by scientists,
veterinarians and doctors who dealt with the disease has painted a detailed
picture of what happened in the field and in the laboratory as the outbreak
took its course.
The Phillips inquiry has established that the
epidemic began 14 years ago. On Dec. 22,
1984, a veterinarian named David Bee was
called to a farm in West Sussex, in southern
England, where a dairy cow known simply as
No. 133 was displaying what he described as
"a variety of unusual clinical manifestations."
By Feb. 11, 1985, No. 133 was dead, and more
cows on the farm were showing symptoms,
including aggression, panic and lack of
coordination.
Bee ruled out several possible causes: lead and
mercury poisoning, fungal contamination of the
feed container, kidney parasites. After six more
cows on the farm died, the farm owners
agreed to allow another sick animal, No. 142,
to be killed so that an autopsy could be
performed by the government. The report
came in on Sept. 19, 1985. The cow's brain
was riddled with spongelike holes, a pathologist
at the government's Central Veterinary
Laboratory in Weybridge, Surrey, said. Cow
142 had a "spongiform encephalopathy."
But it took pathologists more than a year to realize that the spongy-brain
disorder was a disease in itself, and not the result of something else, such as
poisoning. By November 1986, the condition had a name: bovine spongiform
encephalopathy, one of a school of diseases known as transmissible
spongiform encephalopathies, including scrapie, a disorder of sheep, and
kuru, a human disease linked to cannibalism.
By March 1988, the source of bovine spongiform encephalopathy had been
tracked by a Central Veterinary Laboratory epidemiologist to what Daniel
Carleton Gajdusek, a kuru researcher and Nobel laureate, now calls "high-tech
cannibalism" -- the use of performance-enhancing dairy feeds whose protein
came from meat and bone meal from slaughtered sheep and cows. (The
practice of including these ingredients in animal feed is no longer allowed in
the United States.)
The British government quickly announced the formation of a scientific
consultative committee to be led by a professor of zoology at the University of
Oxford, Sir Richard Southwood. This group recommended that ruminant
protein be banned from cattle feed, and a crucial issue being examined by the
inquiry is the efficiency with which that ban was put into effect.
By fall 1988, people were beginning to wonder if the condition could spread to
people who ate meat from sick animals. As Southwood recalled for the
inquiry, "From work on scrapie we considered that the central nervous
system and, to a lesser extent, the lymphatic system were the tissues that
would harbor the agent." As a result, a total ban on the use of certain bovine
offals, including brain, thymus and spleen, was announced in June 1989.
British pet food manufacturers had removed these substances from their dog
and cat food a year earlier, but in May 1990, a house cat came down with a
BSE-like disease, followed by a several zoo animals.
This ominous "species jump" prompted another government action. The
Southwood committee had predicted that, should bovine spongiform
encephalopathy erupt in humans, it would "closely resemble Creutzfeldt-Jakob
disease," a fatal neurodegenerative disease that usually strikes the elderly and,
like kuru, scrapie and BSE, is a transmissible spongiform encephalopathy.
Shortly after the first cat died, a unit was set up at Western General Hospital
in Edinburgh to monitor humans for signs of Creutzfeldt-Jakob disease.
Four years later, in summer 1994, in Wiltshire, the disease first appeared in a
human, when the parents of a Royal Air Force cadet, Stephen Churchill,
noticed that he had slipped behind in school. Soon he had succumbed to
hallucinations. By March 1995, he was undergoing comprehensive tests at the
National Hospital for Neurology and Neurosurgery in London. There, his
mother for the first time saw a possible diagnosis in a note on his chart:
"CJD?"
Stephen Churchill died on May 23, 1995, and by that fall more young people
were found to be stricken with the same illness. Could the disease be
spreading from cows to people? The British government maintained that beef
products were safe. But some scientists began to contradict this position
publicly.
In December 1995, Sir Bernard Tomlinson, a neuropathologist from
Gateshead in northeast England, announced on BBC Radio 4 that he would not
eat beef organs, including calf's liver. The health secretary at the time,
Stephen Dorrell, responded on BBC, saying, "We have removed from the
human food chain the organs that could conceivably be linked to that," and
"There is no conceivable risk from what is now in the food chain."
Nevertheless, only four months later, on March 20, 1996, Dorrell read a
fateful statement before the House of Commons that 10 young people had
died, and "the most likely explanation" was "exposure to BSE." That day the
world learned the name of a new disease: new variant CJD, or human BSE.
The European Union banned the sale of British beef for three years, until
November 1998. In the meantime, according to Britain's Ministry of
Agriculture, Fisheries and Food, more than 4,347,380 cattle were destroyed,
most merely because they were deemed old enough to conceivably harbor the
disease agent. The Ministry of Agriculture has estimated that the total cost will
reach $7.13 billion by 2002.
To date the human death toll stands at 35, with 34 cases in the United
Kingdom and one in France. Scientists who tested tissue samples at the
Neuropathogenesis Unit in Edinburgh and at Imperial College School of
Medicine at St. Mary's Hospital in London said BSE and human BSE are
caused by the same disease agent, possibly a novel form of protein called
prions. Whether humans were infected by bovine products, or from an
independent source entirely, remains unknown.
News last year that two of the British victims had been blood donors has led
to the establishment of a $77.5 million program to strip donated blood of the
white blood cells that might carry the BSE agent. Meanwhile, Britain is
importing most of its blood for plasma, mainly from the United States.
Some scientists regard the small number of cases among humans as a reason
for optimism. But estimates of how many cases may follow vary wildly, from
tens to hundreds to hundreds of thousands.
More than 173,000 cows from all over Britain have been confirmed to be
infected. Hundreds of thousands more might have entered the food supply
undetected.
Though the inquiry has yet to draw conclusions, its work has brought some
comfort to the families of people affected by the disease. "What we want is
the truth," said Stephen Churchill's mother, Dot Churchill. "We believe that's
what we'll be told by the inquiry."
Copyright 1999 The New York Times Company |
