NHS officials are preparing to import more blood from the US because of the small risk that supplies from British donors are contaminated with the human form of BSE.
Transfusions in serious operations for babies and young children would be the first to be affected by the changes which have already been discussed with American suppliers, although ministers have not yet decided to take the precautionary step.
Very young patients would have the longest lives to lead if their operations were successful and thus most likely to de velop the incurable but slow developing variant CJD before other illness or death intervened. The incubation period might be anything between five and more than 50 years.
The changes would affect about 70,000 operations a year when completed although shortages and extra costs would probably mean they were phased in if ministers approved the switch.
The imports would not affect traditional blood transfusions, of red blood cells, since importing such supplies would be impractical.
Blood does not have a long shelf life unless it is expensively frozen and other countries would be reluctant to export huge amounts when many have their own shortages.
But the proposal before ministers is that fresh frozen plasma from blood, now used to clot the blood of trauma victims, those undergoing coronary surgery, people with liver disease and women suffering childbirth complications, should be sourced from abroad instead of Britain. The US has neither BSE nor its human equivalent, although it does have a similar condition in elk and deer.
Other plasma, including that used in clotting factors for people with haemophilia, is already imported under measures designed to stop the spread of variant CJD, intro duced in 1998. But fresh frozen plasma is a single component from a single donor, unlike other clotting factors made in a factory from pooled donations from many thousands of donors. It has been argued that a product from single donations pose a smaller risk of variant CJD .
The government has said that there have been shortages of available alternatives and commercial sources in Europe were not suitable because their countries of origin, even when vCJD-free, were not free of BSE. But the national blood service, covering collection and transfusion in England and north Wales, is looking again at overseas supplies.
