The transfusion of blood and blood products from one person to another is a highly hazardous process and yet has become a widely used and mostly safe treatment, at least where high standards of practice are in place. Sadly, it has taken a number of worldwide epidemics of transfusion-disseminated disease to achieve this degree of safety, through screening of donors, and testing and manipulation of product. The reaction to the recognition of a new hazard has not always been swift; nor have the lessons learnt from previous problems been used to anticipate new threats. The consequences of previous epidemics, hepatitis B (HBV), hepatitis C (HCV) and HIV are still with us, and the long-term effects of prion transmission are unknown. The theoretical risk of acquiring one of these infections from transfusion of red blood cells or platelets supplied by the National Blood Transfusion and Transplantation Service is reliably estimated to be 0.22 per million donations for HIV, 0.05 for HCV and 2.20 for HBV,1 a figure which applies to most Transfusion Services in scientifically developed countries. The reported incidence is even less. These risks of disease transmission are public health concerns as well as tragedy to the recipient. The measures taken to supply as safe a product as possible are fully justified, despite the high cost, and are politically essential. A number of National Committees of experts continuously monitor the risks and advise government on the way to minimise …