The Blood Transfusion Service Board was examining what measures may be necessary if new variant CJD was shown to be transmitted via blood products, the Minister for Health, Mr Cowen, told the Dail.
Stressing that nvCJD, the human form of BSE, was extremely rare, Mr Cowen noted new evidence suggesting that the infectious agent which caused nvCJD may be present in lymph glands, in particular the tonsils of patients with the disease.
He said no data were available on the transmissibility of nvCJD by blood transfusion. Early clarification of the potential link appeared unlikely. "Notwithstanding lack of concrete evidence, precautions are currently in place at the BTSB against any possible spread. These are in line with international practice."
Already, certain groups were excluded from donation, such as people with a family history of CJD, and donors treated with material known to have spread classical CJD, such as human growth hormones. There was, however, no test available for screening blood donations and it would take two to four years to generate one.
Mr Cowen said the nvCJD agent had been detected in lymphoid tissue, indicating it may circulate in white blood cells (leucocytes), which can be removed from blood products by a filtration technique known as leucocyte depletion. It was his Department's view that "there is currently no direct evidence that leucocyte depletion will improve the safety of individual blood components".
However, he confirmed that the British National Blood authority was to start work towards the possible extension of leuco-depletion use if it was shown such a precautionary measure was necessary. The process was also being assessed by the BTSB "to allow for immediate implementation" if necessary.
He said some patient categories already received filtered products to prevent immune reactions, while most platelets used in Irish hospitals were filtered. Special consideration had to be given to frequent users of blood products.
There were no reported cases of CJD in haemophiliacs despite many years of treatment with plasma-derived products. But, in present circumstances, he had decided that plasma-derived Factor 8, used to treat haemophiliacs, should be replaced with a synthetic product, recombinant Factor 8. The BTSB was arranging to have this available from January - the measure would cost £3 million a year.
"It's important to stress that the risks from CJD or nvCJD are purely theoretical at this stage, and any potential risk of contracting nvCJD through blood transfusions is far outweighed by the real risks of compromising health through not accepting a transfusion."
The Fine Gael spokesman on health, Mr Alan Shatter, who tabled an oral question on the matter, said that, given the BTSB's past, there was a need to ensure everything was being done to assure the public that it could have confidence in the supply of blood products.
The Minister, he said, seemed at odds with a BTSB official who was reported to have said that the board was "powerless to eliminate CJD in blood" and to have suggested all red blood cells should be filtered.
Mr Cowen accepted there was no room for complacency. He was satisfied that everything possible was being done by the BTSB. "If any organisation has learned its lesson, it's that particular organisation."
