Nucleic acid testing for transfusion-transmissible agents.

Pooled nucleic acid testing for HIV and hepatitis C virus (HCV) has been successfully implemented in the United States. Reactive rates for nucleic acid testing (NAT) are comparable to those for serological testing. The combined yield for HIV and HCV RNA confirmed-positive, seronegative donations for the 1st year of testing has been 62 HCV NAT-reactive donations among more than 16.3 million screened (1:263,000) and four HIV NAT-reactive, p24 antigen-negative donations among greater than 12.6 million screened (1:13,150,000). The observed yield of NAT confirmed-positive donations is compatible with estimates derived from window-period projections and recent measurements of incidence. Of the HCV NAT-reactive donations identified, one has not sero-converted over a 300-day period. The predominant recent risk factor identified for HCV NAT-reactive donors is intravenous drug use.