Mad Cow And CJD May
Be Transmitted Invisibly
LONDON (AFP) - Scientists have uncovered evidence that the human form of "Mad Cow" disease can be transmitted by people or animals who display none of the symptoms, the Guardian newspaper reported on Tuesday.
The worrying new evidence will force scientists to examine whether the existing controls designed to curb the spread of the deadly infection are tough enough, the newspaper said.
A team led by Professor John Collinge at the Imperial College School of Medicine in London found that mice who had a strain of the infection, variant CJD, injected into their brains lived to an old age and showed no outward signs of the illness.
But when material from the brains of these animals was injected into other mice, the disease killed them, the Guardian reported.
Prof Collinge's study also showed that variant CJD could be transmitted from one species to another more easily than scientists had previously believed.
It said the new research has raised fears that Mad Cow disease, which until now has been confined to cattle, could spread to sheep and pigs.
Prof Collinge said the government should start random checks on outwardly healthy livestock to establish how far the disease had spread.
"I don't want to raise alarms, but we could check that quite easily so why don't we?" the newspaper quoted Prof Collinge as saying. "We don't want to find this out later."
Since the disease first surfaced in humans in 1989, the government has imposed stringent controls to prevent it spreading.
These have included restrictions on farmers and meat producers and tighter checks on blood transfusions.
However,the incidence of variant CJD is growing at between 20 and 30 percent a year, the Guardian said.
In Britain, 70 people have died and a further 10 have contracted the fatal condition, the newspaper said.

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