Regulators Debate U.S. Response to Mad Cow Disease
May 26, 2000 (Washington) -- In April 1989, Joseph Sardo of Miami, Fla., was
assigned to a new project. Soon afterward, he became withdrawn. At first, his
family blamed it on the project. But by June, the data process administrator
who once was able to add columns of 30 numbers in his head, could not even
count back from seven. By August, he was dead at age 66.
Sardo suffered from Creutzfeldt-Jakob Disease, or CJD, a rare brain disorder
characterized by sponge-like microscopic spaces in the nerve cells, called
neurons, that cause progressive dementia and muscle spasms. It is thought to
afflict about one person in 1 million. It can strike anyone, there is no
treatment, it cannot be slowed, and it usually is fatal within one year.
Approximately 10 to 15% of CJD cases are inherited, yet how Sardo and the
others contracted the disease remains unknown, which worries U.S. health
officials. However, with a new, more infectious variation of CJD, better known
as "mad cow disease," now posing an additional threat, they are taking
no chances. In early June, FDA officials will once again meet with an "ad
hoc" advisory committee created in 1995 to discuss what would be an
On the agenda is a blood donor deferral policy that has been credited in
part with creating a national blood shortage, and the merits of a method that
might free up that blood for transfusions as well as the manufacture of plasma
derivatives. Adopted in August 1999, the deferral policy bans the use of blood
donated from people who spent six or more months in the U.K. between January
1980 and December 1996.
The stakes could be high. Mistakes have been made in the past with regards
to CJD and other infectious diseases. Between 1963 and 1985, the National
Institutes of Health (NIH) supplied free of charge a human growth hormone that
infected some recipients with CJD. And in the 1980s, the failure of government
officials to form an appropriate blood donor policy with regards to HIV/AIDS
literally led to an epidemic, during which thousands of Americans were infected
while regulatory officials wrestled with the question of how to respond.
In this case, there are some striking similarities. "We simply don't
know if there is the potential for CJD to be in the blood of donors,"
explains Steve Petteway, director of pathogen safety and research at Bayer
Corp., where groundbreaking work has been done on that subject. But studies
have shown that the infectious agent may reside in the blood of animals, which
lends credibility to the FDA's concern, he says.
To find the answer, scientists around the world are working on a test to
detect an unconventional protein called a prion, a previously unknown
infectious agent believed to be behind CJD. Prions are thought to transform
healthy molecules to a dangerous conformation, causing not only CJD but also
mink encephalopathy, scarpie in goats and sheep, chronic wasting disease of
mule deer and elk, feline spongiform encephalopathy, and bovine spongiform
encephalopathy -- or mad cow disease.