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 ast
week's announcement of a possible cure for variant Creutzfelt-Jakob
disease (vCJD) comes as wonderful news. It also calls into question
the wisdom of some of the "precautionary" measures taken
with regard both to BSE (Bovine Spongiform Encephalopathy) and to
its human equivalent, vCJD.
BSE, or "mad
cow" disease, is a truly postmodern disorder — its psychological
and legislative effect far outweighing its physical impact. Since
it was first detected in the early 1980s, BSE has struck hundreds
of thousands of cattle, most of them in the U.K. But even as the
number of cattle affected has dwindled, over the past decade, fears
about BSE's effects on humans have only grown. In response, governments
have imposed a spate of ultra-precautionary regulations, the net
effect of which is almost certain to be harmful.
Concern about
BSE first arose in Britain in the late 1980s, when scientists suggested
it might cause a similar brain disorder in humans (Creutzfelt-Jakob
disease). Fears were initially allayed by government scientists,
who affirmed that the link was only hypothetical. Nevertheless,
the British government banned the use of rendered meat and bone
meal as animal feed, and imposed stringent restrictions on the sale
of potentially affected tissue to humans. (We might have known something
was up when John Gummer, then U.K. Minister for Agriculture, fed
hamburgers to his children on TV.) Then, in 1996, scientists in
Edinburgh announced the discovery of a new variety of vCJD, which
they suggested might be linked to BSE. And the fearmongers had a
field day.
Variant CJD
is a horrible disease, and one can only feel pity for sufferers
and their families. But vCJD is also exceptionally rare, affecting
fewer than two people in a million. The majority of cases are sporadic,
caused by normal aging of the body's repair mechanisms. A very small
number are caused by an inherited abnormality. And some have also
been traced to medical procedures, including corneal transplants
and injections of human growth hormone.
Just over 100
cases of variant CJD have been identified since 1994. In spite of
millions of dollars of research and thousands of hours of government
inquiries, the cause of vCJD remains mysterious, and any link to
BSE is far from being proven.
Even if vCJD
is caused by exposure to BSE-infected material, it now seems unlikely
that more than a few hundred people will succumb. First, because
in spite of more vigilant monitoring, the observed incidence of
vCJD is not increasing rapidly enough to justify more catastrophic
predictions. And second, because it seems highly likely that a cure,
such as that now being investigated, will be found.
Yet, in June,
the fearmongers were out again, urging policymakers to take action
to prevent exposure to vCJD from infected blood. What's bizarre
is that not a single case of CJD has ever been traced to a blood
transfusion. Indeed, even assuming CJD is transmissible, the risk
of infection from blood donated by someone with CJD is vanishingly
small. The infective agents are protein clusters called "prions"
that have become damaged or "misfolded." These prions
are capable of self-replication; when they come into contact with
healthy prions, they cause them to become likewise misfolded, leading
eventually to a tangle of spongy material. There are, however, very
few prions in blood to begin with (which is why no blood test for
CJD has so far been developed), and so the likelihood of transmitting
the infection in this way is tiny.
If vCJD were
transmitted by blood transfusions, people in Britain and other European
countries would be at a much higher risk of exposure to it. Over
the past 10 years, 30 to 40 million blood transfusions have been
conducted in the U.K. — including several from people who subsequently
died from vCJD. And yet not a single case of vCJD has been detected
among recipients of blood or blood products.
So it seems
unlikely that vCJD can be transmitted through blood or blood products.
Nevertheless, regulators around the world have imposed restrictions
on the use of blood that might have come from donors possibly harboring
vCJD. In 1998, the U.K. banned the use of blood donated by Brits
in the manufacture of blood products. (Britain now imports blood
factors from the U.S.) Several countries, including France and Spain,
have banned blood donations from people who have spent long periods
of time in the U.K. More recently, the American Red Cross — which
collects 45 percent of blood donations in the United States — decided
to ban blood donations from anyone who has spent more than three
months in Britain, or six months in Europe, since 1980.
The Red Cross
decision is particularly serious, as it will lead to a reduction
in the availability of blood and blood products not only in the
U.S., but globally. In total, about 8 percent, or 400,000, of the
Red Cross's current blood donors will become ineligible.
New York City
is already postponing 8 percent of all operations because of the
shortage of blood. Out of excessive caution over a hypothetical
risk, it seems the public is to be exposed to real risks. Thousands
of people will have to wait longer for elective surgery, with resultant
complications and discomfort. In some cases, even patients who require
blood for emergency procedures may have their operations delayed.
Some will probably die. People who rely on blood factors — such
as those with immunodeficiency or hemophilia — will either pay more
for their medication, or will suffer. Some will die.
Further, while
the Red Cross is not permitted to claim that its blood is safer
than that of any other supplier, its move is likely to contribute
to the public confusion over the risk of vCJD. And, of course, federal
regulators may feel pressured to extend the same level of regulation
to other blood suppliers. The U.S. Food and Drug Administration
(FDA) has already overreacted to the threat of vCJD, by banning
blood donations from anyone who spent more than six months in Britain
at any time between 1980 and 1996. Last week, the FDA's Transmissible
Spongiform Encephalopathy Advisory Committee (TSEAC) — a supposedly
'scientific' body — recommended that the current ban be extended
to anyone who lived in Britain for more than three months between
1980 and 1996, and to anyone who was in Europe for five years or
more in that same period. Ironically, one of those supporting the
extension of the ban was Stanley Pruisner, the same researcher who
claims to have discovered a cure for vCJD.
But if the
FDA is really concerned about risks of transmission, these recommendations
actually don't go far enough. After all, if it's logical to ban
donations from one person with a minuscule chance of being infected
— then it must make sense to ban donations from every other potentially
infected person. To be fair, there is presumably a link between
the length of time a person has lived in a place and the number
of roast-beef dinners they might have had there. But if BSE causes
vCJD through infection, then presumably all it takes one dodgy plate
of steak tartare (or Steak Americain, as they call it in Brussels).
In which case, all Americans who have visited Switzerland — which
has had several hundred cases of BSE — should also be banned from
giving blood. And what about those Americans who ate British beef
prior to the import ban in 1989? And, conversely, shouldn't all
those vegans from Portland and Missoula be exempted?
The Red Cross
is a private organization and is entitled to make whatever decisions
it wants with regard to donors — however stupid, and however harmful
to the public. (Though it could be argued that as a recipient of
government largesse, it should be forced to accept some responsibility
for its actions.) The risk we now face, however, is that FDA officials
will feel obliged, in spite of scientific evidence, to force other
blood suppliers to comply with similar restrictions. The recent
TSEAC recommendations certainly suggest this is likely.
In an environment
of heightened fear over the risk of vCJD, the FDA will no doubt
seek the option that minimises blame. To keep supplies "absolutely"
safe, it might soon have to ban imports of blood and blood products
from other countries altogether. Eventually, no doubt, the government
would come under pressure to ban exports of blood, and blood products,
too — after all, we can't have poor people in the U.S. dying while
American blood goes to treat wealthy foreigners. The ensuing trade
war could bring new meaning to the term "blood feud."
In deciding
how to regulate blood products, perhaps the FDA commissioners could
ask themselves this question: Imagine you are about to die from
a life-threatening condition that could be prevented by a blood
transfusion. Would you want the transfusion to be delayed by several
hours, so the hospital could wait for blood from a vegan who's never
travelled abroad? Or would you be willing to accept the unquantifiably
small possibility that the blood you receive is contaminated with
vCJD?
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