- CARDIFF (Reuters) - It will be five years at least before scientists
will know how many people could fall victim to the human version of mad
cow disease, a BSE expert said on Thursday. Professor Roy Anderson, a member
of the government committee investigating spongiform encephalopathies,
the group of brain diseases that includes mad cow disease, said that because
the disease could lie dormant so long it was impossible now to guess how
many people may fall victim to it. ``It will probably take five years until
we can say anything more sensible,'' Anderson told reporters at the annual
science festival. ``We have to learn better to say I don't know.'' To date,
there have been 27 cases in Britain of new variant Creutzfeldt-Jakob Disease
(nvCJD), which rots away the brain causing an inevitable and anguished
death. The discovery that humans could develop a form of the fatal brain-wasting
disease from eating BSE-infected beef sparked an international scare in
1996 and the European Union banned British beef exports worldwide. Anderson
said he was still predicting the Bovine Spongiform Encephalopathy (BSE)
epidemic in cows would be ``at an extremely low level by 2001.'' More than
a million cows have been slaughtered since 1996 in an attempt to wipe it
out. One of the top experts on brain-wasting diseases, Professor John Collinge
of Imperial College London, agreed that the BSE epidemic is on the wane.
``We are moving to the absolute end of this thing,'' he said. After research
with mice, Collinge last year verified that CJD in humans is the same as
BSE in cows and that the new strain of CJD was probably caused by exposure
to infected cattle. He said the main priority was to find a treatment for
nvCJD. ``For several hundred million pounds, you could possibly find a
treatment for the disease,'' he said. But in a sometimes highly-charged
press conference, Professor Richard Lacey of Leeds University, the first
person to warn BSE could be passed to humans, said the incidence of BSE
could be much higher and repeatedly called for mass screening of cows.
He said a reduction in compensation to farmers whose cattle contracted
BSE meant there was now a financial incentive not to report a suspected
animal. ``We know BSE exists in cows but we don't know the incidence,''
he said, dismissing claims that BSE was definitely on the decline. ``I
agree entirely (with Anderson) about the impossibility now of predicting
what is going to happen to the UK population,'' Lacey said. ``But I disagree
on the interpretation of BSE figures.'' All the experts said a warning
that BSE could be present in sheep, was not supported by the evidence.
Professor Jeffrey Almond, a third member of the government's spongiform
encephalopathy advisory committee (SEAC), told the BBC on Monday there
was a theoretical risk that sheep could be infected with BSE. The government
rushed to play down the claims and Armstrong said more than 2,250 dead
sheep had been tested, only nine had been found to have a scrapie-type
illness and in none of those were there signs of BSE. Lacey said even if
BSE had got into sheep, humans should be ``invulnerable.'' Humans are
not thought to be at risk from the conventional form of scrapie that has
infected sheep for centuries.
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