Objective: To evaluate the risk of post-transfusion and postoperative non-A non-B hepatitis in Australia immediately before the introduction of screening for hepatitis C.
Design: Retrospective testing of blood samples from a prospective study of cardiac surgery patients. Samples were taken from transfusion recipients and non-transfused controls at regular intervals for 12 months after surgery during 1987-1989. For all donor, recipient and control samples, alanine aminotransferase (ALT) levels were measured and tests for antibody to hepatitis B (anti-HBc, anti-HBs) and, when available, to hepatitis C (anti-HCV) were performed.
Setting: Cardiac surgery units.
Participants: Participants were included if they lived in the metropolitan area, and had not had a transfusion in the past year.
Main outcome measures: Post-transfusion hepatitis (two consecutive samples showing raised ALT levels, > 90 IU/L with no other known cause); hepatitis C infection and carriage (antibody to hepatitis C).
Results: Post-transfusion hepatitis occurred in 1.1% of 736 recipients of blood not screened for hepatitis C (i.e., two cases per 1000 unscreened units given). No hepatitis occurred in 514 controls. Seven of the eight patients with post-transfusion hepatitis seroconverted to hepatitis C virus infection. Seven of the 26 anti-HCV-positive donations transmitted hepatitis C, six of these were positive by recombinant immunoblot assay (RIBA) (one by second generation testing only) and one was RIBA indeterminate. Nineteen were RIBA non-reactive; one transmitted hepatitis but the recipient did not develop anti-HCV, although hepatitis C RNA was detected in the donation. Serum ALT was raised in four of the six infective donations.
Conclusions: Hepatitis C virus infection accounted for almost all cases of non-A non-B post-transfusion hepatitis. First generation anti-HCV tests detected about 85% of infective donations. Surrogate testing of donations by ALT or anti-HBc offers no additional advantage.