A patient has been diagnosed with variant-Creutzfeldt-Jakob disease nine years after receiving an infected blood transfusion.
The Health Protection Agency (HPA) said it was the fourth case of vCJD to be diagnosed in Britain in connection with a blood transfusion. The patient has not been identified.
The disease is the human form of BSE. It is believed that 158 people have died from definite or probable vCJD since 1990. The HPA said: "A transfusion from the same blood donor was also associated with one of the previously identified cases. The patient is still alive and is under specialist care."
The HPA says fewer than 2 per cent of reported vCJD cases in Britain have been associated with a blood transfusion.
Professor Peter Borriello, director of the HPA's Centre for Infections, said: "This new case of vCJD infection increases our concern about the risk to the small group of people who had blood transfusions from donors who unknowingly at the time of donation must have had vCJD infection.
"However, this new case does not change our understanding of the risk for other people in any specific way. It does, however, reinforce the importance of the precautions that have already been taken to reduce the risk of transmission of vCJD infection by blood," Professor Borriello said.