Purpose of review: While the risks of transfusion-transmitted human immunodeficiency virus, hepatitis C virus, and human T-cell leukemia virus I/II continue to decrease, additional threats to transfusion safety are posed by emerging “new” infectious diseases.
Recent findings: Following the introduction of nucleic acid testing for human immunodeficiency virus and hepatitis C virus, the American Red Cross estimates the risk of transfusion-transmitted human immunodeficiency virus to be 1:1,215,000 (per unit transfused) and 1:1,935,000 for transfusion-transmitted hepatitis C virus. Hepatitis B virus nucleic acid testing has not been implemented, and the risk of transfusion-transmitted hepatitis B virus in the United States remains relatively high at an estimated 1:205,000. The risk of transfusion-transmitted human T-cell leukemia virus I/II is 1:2,993,000, based on Red Cross estimates. Nucleic acid testing for West Nile virus began in the United States in 2003 under an investigational new drug program. No approved laboratory tests are available to screen the blood for Chagas disease, malaria, severe acute respiratory syndrome, or variant Creutzfeldt-Jakob disease.
Summary: Prevention of these potential transfusion-transmitted infections is addressed by deferring potential donors whose personal behaviors or travel histories place them at risk.