Abstract

Donated blood provides invaluable therapeutic proteins and cells; it can also transmit infection. It was originally used entirely as whole blood for volume replacement, but now this use is rare. Instead over 90% of donated blood is now separated into its various constituents,¹ allowing different components to be prescribed individually and pooled plasma to be used in the manufacture of a range of special fractions with each product given for specific conditions. Such separation allows for more efficient use of blood but it also increases the risk of transmitted infection since the products of a single contaminated donation may be given to many recipients. This article describes the blood constituents themselves, and considers the methods used for preventing transmission of infection and the risks that remain.