A committee of scientists set up to advise the Government on BSE - so-called Mad Cow Disease - and its human equivalent CJD, is to recommend that all blood supplies be treated to prevent any possibility of infection.

The panel stresses there is no evidence that CJD has ever been transferred in this way but they are urging the Government to be extra cautious in case there is any risk, no matter how small. It is a precaution already practised in some other countries.

Scientists close to BSE test breakthrough

In Britain 22 people have died from new variant CJD, two of whom were known to be blood donors. The National Blood Authority has recalled batches of blood products made from their blood as so far testing for the disease has not been possible.

However, scientists in Switzerland now say they are close to developing a test for both the animal and human forms of the disease.

Researchers from Prionics AG, based at the University of Zurich, have developed an antibody which recognises prions - the infectious particles of protein which spread diseases like CJD and bovine spongiform encephalopathy.

The test will work for both human and cow forms of the disease

Until now scientists have not been able to differentiate between proteins that are normally present in the body and the malignant form which causes the disease.

In a report in the science journal Nature, researcher Bruno Oesch described how he and his colleagues isolated the antibody, 15B3 that can distinguish between good and bad brain prions.

Mr Oesch says the breakthrough could lead to a test being developed which could detect the early stages of CJD and BSE in the future.

"The new antibodies will potentially be able to detect prion production in blood which will be useful in detecting the early stages of BSE in cattle and CJD in humans," said Mr Oesch.

Bruno Oesch: 'a tool for screening donated blood'

"It will also be a tool for screening donated blood and prevent large batches of products having to be recalled."

The only test for BSE and CJD which currently exists examines the brain tissue from victims.

It is not very effective and can only be carried out once the cattle or a person has died, added Mr Oesch.

Professor Richard Lacey, the first person to warn that BSE could spread to people, welcomed the development but warned it may have come too late.

"This is the bare bones for a test which identifies which cattle will get ill and which people might be incubating the disease.

"It is a step forward but it is still not known how much abnormal prion production is needed to cause the disease.

"Therefore to validate the test, it needs to be looked at prospectively for some years to see whether findings correlate with events.

"With cattle this could be five or six years, with humans it could be decades."

He said because of the length of time needed to establish the test, for many people it would come too late.

"The worse scenario is coming closer and is very real. After crossing from cattle to humans the disease could then spread rapidly between humans," said Prof Lacey.

CJD, like BSE, is a poorly understood condition that attacks the brain, leaving it full of holes like a bath sponge.

Victims display symptoms of dementia, becoming unsteady, confused and losing their memory.
 

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