Longitudinal follow‐up of blood donors found to be reactive for antibody to human immunodeficiency virus (anti‐HIV) by enzyme‐linked immunoassay (EIA+) but negative by western blot (WBμ)

Abstract

A cohort of 467 volunteer blood donors who were found to be EIA+/WB- was studied longitudinally for up to two years. EIA screening for anti-HIV and WB testing, regardless of the EIA results, was performed on all 769 subsequent donation events of this cohort to ascertain the consistency of test results over time. The following results were obtained: 1) 8.8% of subsequent donation events were EIA+; 2) Most donors who returned were found to be EIA-/WB-; 3) EIA-/WB? (indeterminate) was 14.5 times more common than EIA+/WB?; 4) EIA and and WB results were generally inconsistent from donation to donation; 5) No donor was found to be WB+. These results suggest that, in a volunteer donor population, an EIA+/WB- result may have little value in predicting anti-HIV test results and AIDS infectivity in a future donation. The current practice of not using blood donated subsequently by EIA+/WB- donors unless a re-entry testing scheme is satisfactorily completed should be reconsidered.