Levels of hepatitis C virus in blood donors infected with different viral genotypes. International HCV Collaborative Study Group.

The level of hepatitis C virus (HCV) in the serum of 337 blood donors infected with different viral genotypes was investigated by branched DNA assay. Viral genotype was deduced by restriction analysis of the virus 5'-noncoding region. Samples included genotypes 1a, 1b, 2a, 2b, 3,4,5, and 6. Multivariate analysis revealed that the ranges of HCV levels were similar for all viral genotypes and subtypes (P=.18), with the possible exception of genotype 4. Virus levels were significantly lower in female than in male subjects (P<.001) but did not correlate with donor age (P=.06) or genotype or with donor age, sex, or country. These results indicate a similar replicative capacity in vivo for different HCV genotypes and clarify the influence of host and virus factors on disease severity and responsiveness to interferon treatment.