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The
French research was based on studies of monkeys
(Excerpt - for complete
text please visit BBC.com)
January 27, 2005 from BBC.com
Current safety precautions are enough
to protect humans against mad cow disease, according
to BSE experts.
| "To
become infected you would need to eat an enormous
amount of brain, which is not possible."
Lead Researcher Dr Jean-Philippe
Deslys
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Banning brain, spinal tissue and older
cattle from the food chain has worked, the French team
told the Lancet.
By studying monkeys, they estimated how
much infected tissue a human would have to eat to be
at risk and said it would be more than anyone could
consume.
UK experts said the exact quantity remained
an enigma and recommended continued surveillance.
The Commissariat à l'Energie Atomique
scientists estimate that a person would have to eat
at least 1·5kg of neural (brain and spinal) tissue
to be at risk of developing variant Creutzfeldt-Jakob
disease (vCJD).
This applies to cattle that screen negative
for disease when they are slaughtered but harbour low
levels of infection.
Lead researcher Dr Jean-Philippe Deslys
said this meant even if the UK switched to screening
cattle older than 30 months for BSE, as is done in other
parts of Europe, rather than banning sale of this produce,
food would still be safe to eat.
Food Chain
Based on his team's tests on two monkeys
and previous primate research, he also believes that
transmission between cows and primates/humans is far
less likely than it is between cattle.
"The efficiency of infection from
cow to primate could be seven to 20 times lower than
that of intraspecies infection for cattle," he
said.
The incubation period for BSE transmission
from cattle to human could be more than a third longer
than that of human-to-human transmission, he added.
Although the present data does not provide
a definitive minimum infective dose for transmission
of cattle BSE to primates, Dr Deslys said it did give
enough information to know that existing measures to
protect our food supplies were adequate.
Continued surveillance will be required
for a considerable time.
Professor James Ironside of the National
CJD Surveillance Unit: "To become infected you
would need to eat an enormous amount of brain, which
is not possible.
"The measures taken now really give
a guarantee of food safety and future crises can be
avoided."
Full
Story...
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