Prevalence of antibodies to hepatitis C virus in relation to surrogate markers in a blood donor population of Singapore.

Prevalence of antibodies to HCV is studied among a blood donor population in Singapore and its relationship to surrogate markers was examined. Sequential serum samples from 4,091 blood donors were tested for the presence of anti-HCV using the second generation immunoassay (Abbott). 275 random serum samples were tested for anti-HBc and ALT. All the samples positive for anti-HCV were also tested for anti-HBc and ALT. Only 22 of the 4,091 donor samples (0.54%) were repeatedly reactive for anti-HCV. Of the 275 random samples tested, 43 samples (15.6%) were positive for anti-HBc and 24 (8.7%) had ALT levels more than 45 IU/l. None of these 67 samples were positive for anti-HCV. Only 3 of the 22 anti-HCV positive samples (13.6%) were positive for anti-HBc and only 6 samples (27.2%) had ALT level more than 45 IU/l. The prevalence of anti-HCV among the donors is only 0.54% which is much lower than the prevalence of HBV. An important finding is that about 60% of the donors positive for anti-HCV had no detectable surrogate markers. Exclusion of blood donors positive for anti-HBc, if implemented in an area where the prevalence of HBV infection is relatively high will result in the loss of blood donors estimated to be 15.6% and the use of raised ALT will result in a further loss of 6.1% of the blood donors.