A support group for victims of CJD has welcomed news of a blood test to detect the human form of mad cow disease.
Screening could protect patients needing blood transfusions
The process developed by a team at the University of Texas has been tried on hamsters and raises hopes people could be screened for variant CJD.
Until now, the only way to confirm vCJD has been through checks after death.
The new method could help protect people receiving blood transfusions or organ donations as well as experts trying to predict any future epidemic.
There have been 180 deaths from vCJD since the condition was first seen in 1995, the majority of them in the UK.
In 2003 the government announced the first case of a patient who died from vCJD after receiving blood from an infected donor.
Dr Angus Kennedy of the Shropshire-based CJD Support Network told BBC One's Breakfast programme developing a blood test was crucial to combating the illness.
"If it is a way of diagnosing it earlier and detecting it in the bloods of infected individuals, that would be very important for detecting it sooner and that might help when we have got appropriate treatments," he said.
But, he cautioned, "Work needs to be done to reproduce it to see whether it actually works in human beings".
In a paper published in monthly journal Nature Medicine, the University of Texas team says it has been able to accurately identify within 48 hours minute quantities of the particles thought to cause the fatal brain disease.
The so-called rogue prions that cause vCJD are able to side-step the body's defences and enter the bloodstream.
Researchers used sound waves to accelerate the process the prions use to convert normal proteins to the infectious, or rogue, forms.
"The concentration of infectious prion protein in blood is far too small to be detected by the methods used to detect it in the brain, but we know it's still enough to spread the disease," said Professor Claudio Soto.