Prevalence, incidence, and residual risk of major blood-borne infections among apheresis collections to the American Red Cross Blood Services, 2004 through 2008.

Background: The number of apheresis collections increased significantly in recent years; however, data on viral marker rates among these collections are lacking.
Study Design and Methods: Apheresis collection data for 2004 to 2008 were analyzed. All collections were tested for antibodies and viral RNA for human immunodeficiency virus (HIV) and hepatitis C virus (HCV), hepatitis B surface antigen (HBsAg), antibody to hepatitis B core antigen (anti-HBc), antibody to human T-lymphotropic virus (anti-HTLV), and other markers. HBsAg-confirmed-positive but anti-HBc-nonreactive units were further verified by HBV DNA testing.
Results: From 2004 to 2008, apheresis collections for double red blood cells (R2) increased by 294% to a total of 37% of all apheresis collections. Marker rates (/100,000) among all apheresis collections were 1.41, 7.83, 2.04, and 0.28, for HIV, HCV, HBsAg, and HTLV. Among R2 collections, rates (/100,000) were 6- to 13-fold higher than among non-R2 collections for HIV (3.50 vs. 0.53), HCV (21.84 vs. 1.96), and HBsAg (5.83 vs. 0.44), but not HTLV (0.53 vs. 018). First-time male R2 donors accounted for 25% to 100% of positivity but only 1% to 5% of the total number of apheresis collections. Incidence (/100,000 person-years) and residual risk estimates among repeat apheresis donors between 2007 and 2008 for HIV were 3.82 and 1:1.0 million, for HCV were 1.53 and 1:3.2 million, and for HBsAg were 4.85 and 1:200,000. These estimates were comparable to those among repeat whole blood donors.
Conclusion: The risk of major blood-borne infections among current apheresis collections was low; however, an upward trend in the viral marker frequency among apheresis donations was attributable to the contribution of first-time, male R2 donors.