The question of deferring different categories of blood donors from donating blood is a matter for the Blood Transfusion Service Board. There is no proven instance of classical CJD having been transmitted through blood or blood products, but the theoretical possibility associated with variant CJD cannot be excluded at this time. There is currently no screening test to detect the presence of variant CJD. For my part, I will ensure the BTSB has adequate resources to introduce proven new technologies in this area.
Experimental animal models suggest that the infectivity of Transmissible Spongiform Encephalopathies, which include variant CJD, may be associated with white blood cells in animal systems. White blood cells can be removed from blood donations using special filters. This process is called leucodepletion, and the BTSB, as a precautionary measure to minimise the theoretical risk of transmission, introduced leucodepletion for cellular products in 1999.
The BTSB's policy is to permanently defer potential donors who may be at risk of carrying CJD, including donors who have received a dura mater transplant, human pituitary derived growth hormone or have one or more blood relatives with CJD.
The countries referred to by the Deputy recommend that potential blood donors who spent a total of six months or more in the United Kingdom between 1980 and 1996 be permanently deferred from donating blood. As part of the decision-making process, the countries in question assessed the likely effect of such decisions on their blood procurement policies. I understand the effects for those countries was in the order of a 2% reduction in supply whereas the effect in this country would be a 13% shortfall in donors.
The Council of Europe's Committee of Experts on Blood Transfusion and Immunohaematology recommend that the balance of risk between maintaining an adequate blood supply and minimising a theoretical risk has to be considered in the decision-making process and it advises that care must be taken to ensure any precautionary measure proposed will not impact adversely on the donation, safety and supply of blood necessary to meet patients' needs. Furthermore, the populations of Ireland and other European countries differ from those of countries such as North America in the extent of their exposure to UK bovine-derived material. In countries with a higher historical exposure to BSE, measures to defer donors who have spent time in the United Kingdom may reduce donor supply without enhancing safety. European countries are actively evaluating this matter at present.
The Irish Medicines Board, which is the regulatory authority, has indicated that it is anxious to consult more widely with national and international expertise and have more detailed discussions on the matter before recommending any change in the current position. It supports the BTSB's proposals to re-enforce guidelines on the optimal use of blood in hospitals.
The strategy of ongoing monitoring of the emerging scientific data will continue as a matter of priority, involving the BTSB, the Irish Medicines Board, and the CJD advisory group, which is advising me on matters relevant to CJD. I am planning to have a series of consultations with these bodies to keep the matter under constant review. The advice and evidence from EU scientific and medical experts is also being regularly evaluated to assess whether current strategies ought to be revised and this will continue to be the case. I will ensure adequate resources are available for this purpose.