Anti-HBc screening detects HBsAg EIA-negative, HBV-infected donors at a rate comparable to the estimated residual risk for HBV window-period infections. The low viral load in the HBV DNA-positive samples suggests that minipool NAT will not detect most potentially infectious units from anti-HBc-positive donors.

Medical and behavioral screening does not eliminate HHV-8-seropositive persons from the US blood donor pool, but no viral DNA was found in donor blood. Further studies of much larger numbers of seropositive individuals will be required to more completely assess the rate of viremia and possibility of HHV-8 transfusion transmission. Current data do not indicate a need to screen US blood donors for HHV-8.

Although previous investigations showed frequent detection of CMV DNA in healthy CMV-seropositive (and some seronegative) blood donors, these studies were relatively small and the performance characteristics of their assays were difficult to evaluate. In contrast, the present large cross-sectional study of US donors utilized two previously validated PCR assays and demonstrated that CMV DNA is only rarely detectable in seropositive donors. Thus, the use of CMV PCR assays with optimal performance characteristics did not increase the detection of potentially infectious blood components beyond that provided by current serologic screening assays.