FREQUENT REINFECTION AND REACTIVATION OF HEPATITIS-C VIRUS GENOTYPES IN MULTITRANSFUSED HEMOPHILIACS

The frequency and dynamics of infection with different genotypes of he patitis C virus were investigated in a cohort of hemophiliacs repeated ly exposed to non-virus-inactivated clotting factor. Among 63 infected hemophiliacs, genotype 1 (n = 38, subtypes 1a [27] and 1b [11]) was p redominant; genotypes 2a (n = 1), 2b (n = 3), 3a (n = 20), and 5a (n = 1) accounted for the remainder. This distribution was similar to that found in Scottish blood donors from whom the infected blood products were manufactured. Hemophiliacs with severe disease were more likely t o be polymerase chain reaction-positive than those with moderate or mi ld disease. Over 10 years, changes in the circulating major genotype a nd serotype were observed in 9 of 29 hemophiliacs and from one subtype to another in 3, although there was no clear trend toward replacement with any particular variant. Replacement occurred after the introduct ion of inactivated clotting factor in 4 subjects, implicating reactiva tion rather than reinfection. Those coinfected with human immunodefici ency virus were more likely to show a change in genotype.