During a follow-up period of 23-40 months, 7 regular blood donors had persistently, and 4 had
intermittently indeterminate anti-p24^gag reactivity in human immunodeficiency virus (HIV)-l Western Blot. Serological
testing and viral cultures revealed that these donors had no signs of infection for HIV-1, HIV-2, human T-cell
lymphotropic virus (HTLV)-4, and HTLV-1. Extensive interviewing and physical examination of these donors
revealed neither risk factors, nor signs of HIV infection in the tested donors. Ten recipients, who were transfused
with blood products from 6 of these 11 anti-p24^gag-positive donors, were traced back. Six months after transfusion,
no serological or clinical signs of HIV-1, HIV-2, or HTLV-1 infection were observed in these patients. It is concluded
that blood donors with persistent or intermittent anti-p24^gag reactivity in HIV-1 Western Blot, without development
of antibodies to other HIV-encoded proteins in later blood samples, do not transmit the described retroviruses to
transfused patients.