Scientists in Britain have warned many more people could become infected with Variant CJD than previously thought.
It follows analysis of a probable transmission of the human form of Mad Cow Disease via a blood transfusion.
Experts at the CJD Surveillance Unit have found the patient's genetic make-up differed from that of any other person so far diagnosed with the disease.
They say this suggests that wider groups of people could be at risk than was thought.
