There is currently no validated diagnostic test that would allow blood donors to be assessed as asymptomatic carriers of variant Creutzfeld-Jakob Disease (vCJD). Therefore, together with the National Blood Service, the Department has introduced a range of measures to minimise the possible risk of secondary vCJD infection through the blood supply. In July 1998 the Department announced that plasma for the manufacture of blood products, such as clotting factors, would be obtained from non-United Kingdom sources. Since October 1999, white blood cells (which may carry the greatest risk of transmitting vCJD) have been removed from all blood used in transfusion. In August 2002 the Department announced that fresh frozen plasma for treating babies and young children born after 1 January 1996 would be obtained from the United States of America, and from summer 2005 this was extended to all children under 16 years of age. In December 2002, the Department completed its purchase of the largest remaining independent USA plasma collector, Life Resources Incorporated to secure long-term supplies of non-UK blood plasma for the benefit of national health service patients. Since April 2004, blood donations have not been accepted from people who have themselves received a blood transfusion in the UK since 1980. This was extended in August 2004 to include apheresis donors and donors who are unsure if they had previously had a blood transfusion. Since late 2005, blood donations have not been accepted from donors whose blood was transfused to patients who later developed vCJD.
The Department will continue to consider further steps to ensure the safety of the blood supply as new evidence or suitable technologies become available.
A cost/benefit analysis of introducing prion removal blood filters can only be completed once the Department has received both results of clinical safety trials and the independent evaluation of the effectiveness of the filters in reducing infectivity requested by the Spongiform Encephalopathy Advisory Committee and the Advisory Committee on the Microbiological Safety of Blood and Tissues and Organs. The analysis will also need to be informed by the outcome of variant Creutzfeldt-Jakob Disease prevalence studies currently under way.