A report on transmissible spongiform encephalopathies and transfusion safety.

The incidence of BSE in Europe is in continued decline. At present, iatrogenic transmission from person to person is considered a serious threat to public health. This report of the International Society of Blood Transfusion Working Party on Transmissible Spongiform Encephalopathy will focus on the state of the art in relation to blood components and plasma safety. Latest information on the pathogenicity of the infectious agent, the frequency and dynamics of infection in blood and transfusion transmissibility will be documented. Preventive measures including donor deferral policies, technologies for prion removal from labile blood components and for prion detection in plasma, the absence of a sensitive and rapid reference assay able to confirm the positive results from any putative blood screening assay will be updated. At last, as many uncertainties remain and a number of assumptions await confirmation, the areas to continue to explore are listed.