On World Blood Donor Day 2016, here is an Open Access Article from the journal Infectious Disorders – Drug Targets
Author(s): Paul F. Lindholm, Kyle Annen and Glenn Ramsey
Abstract: The use of blood donor history and state-of-the-art FDA-licensed serological and nucleic acid testing (NAT) assays have greatly reduced the “infectious window” for several transfusion-transmitted pathogens. Currently transmission of human immunodeficiency virus (HIV), Human T-cell Lymphotropic Virus (HTLV), hepatitis viruses and West Nile Virus are rare events. The seroprevalence of cytomegalovirus in the donor population is high and cytomegalovirus infection can cause significant complications for immunocompromised recipients of blood transfusion. Careful use of CMV seronegative blood resources and leukoreduction of blood products are able to prevent most CMV infections in these patients. Currently, bacterial contamination of platelet concentrates is the greatest remaining infectious disease risk in blood transfusion.
Read more about it here: http://benthamscience.com/journals/infectious-disorders-drug-targets/volume/11/issue/1/page/45/