STEADY-STATE CALCULATION OF THE RISK OF HIV-INFECTION FROM TRANSFUSION OF SCREENED BLOOD FROM REPEAT DONORS

All blood donations in the United States are screened for human immuno deficiency virus (HIV), the virus that causes AIDS; in spite of this, potentially infectious donations are still made by donors who are infe ctious but have not yet developed detectable HIV antibodies. A steady- state model for blood donations is used to calculate the expected numb er of potentially infectious blood donations made by repeat blood dono rs in a specified time interval. The expected number of potentially in fectious donations made by each infectious blood donor who subsequentl y becomes HIV positive is calculated, and estimators of this quantity are presented. The relative risks due to donations from repeat and fir st-time donors is discussed. Estimates of the proportion of all blood donations made at 19 American Red Cross regional blood centers that ar e potentially infectious are presented. Published 1997 by Elsevier Sci ence, Inc.