Abstract
The provision of a safe and sufficient blood supply is critical to patient care. Volunteers who are carefully screened for health problems prior to donation help maintain the blood supply in the United States. Eight million volunteers donate over 12.6 million units of whole blood in the United States each year. The units are transfused to about 4 million patients annually. As a result of donor screening and testing of components for specific pathogens, the risks associated with transfusion have been greatly reduced. Donors are excluded only if they are currently engaged (or have ever engaged) in unsafe sex, use intravenous drugs, received a tattoo recently, or visited places endemic for HIV, or if they lived in Great Britain for longer than 6 months. The Food and Drug Administration (FDA) requires that all donated blood be tested for HIV-1 and HIV-2, human T-cell lymphotropic viruses, hepatitis B surface antigen, hepatitis C virus (HCV), and syphilis [T1]. Cytomegalovirus (CMV) screening is generally done after collection when CMV seronegative products are required. Presently, testing is not routinely done for human parvovirus B19, hepatitis A virus (HAV), hepatitis G virus, or hepatitis E virus
