Infectious organism | Test method used and comments on testing |
Babesia microti (babesiosis) | Units collected in high-risk regions of the United States undergo nucleic acid minipool testing for parasite nucleic acid. |
Cytomegalovirus | Selected units may be tested to establish a CMV-negative inventory for at-risk recipients, using an immunoassay for anti-CMV antibodies.* |
Hepatitis B virus | All units; immunoassay for HBsAg and HBc antibody and nucleic acid minipool testing for viral DNA. |
Hepatitis C virus | All units; immunoassay for antibody and nucleic acid minipool testing for viral RNA. |
HIV-1 and 2 | All units; immunoassay for antibody (with further confirmation testing if reactive) and nucleic acid minipool testing for viral RNA. |
HTLV-I and II | All units; immunoassay for antibody (with further confirmation testing if reactive). |
Treponema pallidum (syphilis) | All units; usually immunoassay for T. pallidum-specific antibody; may also perform an additional non-treponemal immunoassay on reactive samples to help determine when infection occurred. |
Trypanosoma cruzi (Chagas disease) | The initial donation from all donors is screened by immunoassay for antibody (with further confirmation testing if reactive). Repeat donations from previously-tested donors do not require retesting. |
West Nile virus | All units; nucleic acid minipool or individual donation testing for viral RNA. |
Zika virus | Previously all units, using nucleic acid minipool or individual donation testing for viral RNA; phased out in 2021 due to documented absence of ongoing risk. |
CMV: cytomegalovirus; HBc: hepatitis B core antigen; HBsAg: hepatitis B surface antigen; HIV: human immunodeficiency virus; HTLV: human T-lymphotropic virus.
* Refer to UpToDate text and table on risk of viral and bacterial infection from blood products for further details of CMV-reduced risk units.