Hepatitis C virus genotypes in Estonia

Distribution of hepatitis C virus (HCV) geno(sub)types among 215 Estonian p atients hospitalized with acute or chronic hepatitis and with HCV RNA-posit ive sera was investigated. For genotyping, both multiplex PCR with subtype- specific primers of the core region and RFLP analysis of cDNA of the 5' NCR region were used. These two methods permitted a correct characterization o f genotypes, a more truthful characterization of mixed infections, and comb ined use of single-tube performances. They revealed, respectively, 200 and 202 (93.0% and 93.9%) HCV-positive samples of sera, subtype 1a - 0.9% and 0 .9%, 1b - 56.3% and 64.2%, 3a - 13.9% and 22.3%, 2a - 6.5% and 5.6%, type 4 - 0.5% and 0%, mixed infections - 13.5% and 0%, and unidentified - 1.4% an d 0.9%. In the majority of cases (84.7%) both methods gave completely or pa rtially concordant results; in mixed infections, as determined by subtype-s pecific PCR, only one subtype was revealed by the RFLP method. In the remai ning 15.3% of the cases (Ohno - 7.0%, RFLP - 8.3%) only one of the methods was positive. The epidemiological analysis of the dynamics of the subtypes' relative participation may indicate increasing 3a and decreasing 1b subtyp e infection during recent years.