In the past two decades, health services in the developed world have directed much resource toward improving the safety of the blood supply. Blood is collected, tested, and processed within a carefully controlled environment, and quality is assured by rigorous donor selection procedures and increasingly sensitive and sophisticated testing for transfusion-transmitted pathogens. Additional safety strategies implemented by some blood services include leukocyte reduction, bacterial screening, and pathogen inactivation. Thus, the transfusion chain from the donor to the point of issue from the blood center is highly regulated and secure, and transfusion-transmitted infection is an increasingly rare event.