Investigation of the relative infectivity and pathogenicity of different hepatitis C virus genotypes in hemophiliacs.

To assess the relative infectivity and pathogenicity of variants of hepatitis C virus (HCV) genotypes, the distribution of genotypes in hemophilic patients who had been treated with nonvirally inactivated factor concentrates or cryoprecipitates prepared from local blood donors was compared with those found in the respective blood donor populations. Genotype frequencies differed markedly in the four countries investigated (Scotland, Hungary, South Africa, and Thailand) but in each, the HCV genotype distributions in hemophiliacs and blood donors were similar. In addition, HCV genotypes in recipients of commercially manufactured concentrates were similar to those found in the US general population. These findings provide no evidence that HCV genotypes differ significantly from each other in replication rate, transmissibility, or infectivity.