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Blood donor screening: Laboratory testing

Steven Kleinman, MD
Section Editor
Arthur J Silvergleid, MD
Deputy Editor
Jennifer S Tirnauer, MD


Laboratory testing of donated blood prior to transfusion is intended to ensure that recipients receive the safest possible blood products. As of late 2016, such testing consists of determining the ABO blood group and Rh blood type of the donated unit, testing for red cell antibodies, and performing infectious disease screening for the following agents: human immunodeficiency virus (HIV)-1, HIV-2, human T-lymphotropic virus (HTLV)-I, HTLV-II, hepatitis C virus, hepatitis B virus, West Nile virus, Treponema pallidum (syphilis), Trypanosoma cruzi (Chagas disease, only required to be performed on the first donation by a particular donor), and Zika virus (table 1) [1-3]. All infectious disease screening assays must be negative in order to release the blood unit or its components to hospitals for transfusion.

In addition to these tests, some donated units are tested for Babesia microti and some for cytomegalovirus (CMV) antibodies, and virtually all apheresis platelet units are tested for bacterial contamination by an automated culturing technique initiated 24 hours after collection. (See "Transfusion-transmitted bacterial infection", section on 'Detection of contamination'.) Whole blood derived platelets undergo bacterial testing with point of release immunoassays.

This review will discuss the various protocols in place for the laboratory testing of donated blood, with emphasis on screening for infectious agents. Specific discussions of transfusion-transmitted infections are presented separately. (See "Risk of HIV from blood transfusion" and "Epidemiology and transmission of hepatitis C virus infection" and "Transfusion-transmitted bacterial infection".)

Additional safety measures related to blood donor screening are presented separately. (See "Blood donor screening: Procedures and processes to enhance safety for the blood recipient and the blood donor" and "Blood donor screening: Medical history".)


Overview of laboratory testing — Prior to 1985, only two infectious disease screening assays were performed on donated blood. Many additional assays have subsequently been introduced into routine blood screening (table 2); several of these assays have undergone significant modifications to increase sensitivity and specificity (these revised assays are designated by a change in name, or generation or version number) [4]. Minipool nucleic acid testing (NAT) was added to routine serological screening in 1999.

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Literature review current through: Nov 2017. | This topic last updated: Nov 08, 2017.
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