Prevalence of HCV-RNA-positive blood donors and correlation to ELISA and RIBA status.

In Germany, transmission of hepatitis C virus by blood transfusion is prevented by screening the donations for anti-HCV and ALT. The specificity of the anti-HCV screening in low seroprevalence populations has been questioned. In order to evaluate this screening policy we wanted to estimate the prevalence of viremic and potentially infectious donors by the HCV-RNA polymerase chain reaction (PCR) in our donor population of southern Germany. Donors (n = 301) were divided into four subgroups according to anti-HCV status and ALT levels. HCV sequences were detected by nested PCR, using primers for the most conserved region of the viral genome. The recombinant immunoblot assay (RIBA-4) was applied to the same samples. PCR detected 4.2% HCV-RNA carriers in the subgroup anti-HCV-/ALT-; 3% in the subgroup anti-HCV-/ALT+; 19.4% in the subgroup anti-HCV+/ALT-; and 59.4% in the subgroup anti-HCV+/ALT+. It was concluded that, on the one hand, the lack of specificity of the anti-HCV ELISA gives rise to many false-positive results; on the other hand, a minority of infected donations will not be detected by the screening procedure. ALT in conjunction with anti-HCV improves the quality of screening for potentially infectious donors.