Prevalence of hepatitis C virus (HCV) genotypes in central Italy.

Hepatitis C virus (HCV) exposure is due mainly to infected human blood. Most people with acute HCV infection are unable to clear the virus leading to chronic infection that may progress to cirrhosis and hepatocellular carcinoma. HCV genotyping is very useful to optimize the therapy because it helps to identify the patients that need a more aggressive management (e.g., type 1). The aim of this study was to detect the HCV genotype of 915 patients of Central Italy and to analyze the possible change in the prevalence of genotypes not common in Italy, such as type 4. We used a line-probe assay (INNO-LiPA HCV II, Innogenetics) based on reverse hybridization of HCV genome fragments previously amplified by a Polymerase Chain Reaction assay, COBAS System Amplicor HCV monitor version 2.0 (Roche Diagnostics Systems Inc.). HCV type 1 was detected in 448 cases (49.0%), type 2 in 318 cases (34.8%), type 3 in 109 cases (11.9%), type 4 in 33 cases (3.6%) and co-infections in 7 cases (0.7%). In particular, 339 cases (37.0%) showed subtype 1b, 302 cases (33.0%) 2a/2c, 108 cases (11.8%) 3a and 74 cases (8.1%) subtype 1a. The prevalence of type 4 was 3.3% from September 1999 to July 2002 and 4.5% from August 2002 to April 2003. We confirmed that HCV type 1 is prevalent in Central Italy, in particular subtype 1b, followed by type 2a/2c. We also described that the prevalence of type 4 seems to have increased whereas co-infection is a rare event.