Infectious risks of blood transfusion.

The public demand for a "zero-risk" blood supply in the wake of transfusion-transmitted HIV has prompted many changes in the donor selection process, donor testing, and postcollection processing of blood and blood products. The effectiveness of these new strategies has had a remarkable impact: The risk for HIV is now estimated to be one in 1 million units transfused. The risk for other transfusion-transmitted viral infections has similarly been reduced. On the heels of the success of research endeavors targeting transfusion-related viral risk reduction, new concerns regarding transmission of other infectious agents (e.g., bacteria, parasites, and prions) by transfusion have emerged. Consequently, investigative efforts that are even more vigorous are under way, aiming to define the characteristics of transmission as well as identify useful technologies to detect or eliminate these infectious agents.