Distribution of hepatitis C virus genotypes and subtypes in Croatia: 2008-2015.

OBJECTIVE: Hepatitis C virus (HCV) genotyping is an important part of pre-treatment diagnostic algorithms as it guides the choice of therapeutic regimens. The aim of this study was to analyse the distribution of HCV genotypes in patients with chronic hepatitis C from Croatia in the period 2008-2015.

METHODS: The study enrolled 3,655 anti-HCV positive patients with available results of HCV genotyping from the three largest national HCV genotyping laboratories.

RESULTS: The majority of HCV-infected individuals enrolled in the study were male (70.7%). Analysis of age distribution in a subset of 2,164 individuals showed a mean age of 40.9 years (SD 11.77 years). Croatian patients were mostly infected with HCV genotype 1 (56.6%), followed by genotype 3 (37.3%), genotype 4 (4.2%) and genotype 2 (1.8%). Genotype 1 subtyping in a subset of 1,488 patients showed 54% (803/1,488) of 1b infections and 46% (685/1,488) of 1a infections. Percentages of genotype 1 were the highest in Central/Northwestern and Eastern Croatia and the lowest in the Central/Southern Adriatic Region. Genotype 3 was most frequently found in the Central/Southern Adriatic Region (49.1%) but represented only 17.5% of infections in Eastern Croatia (p < 0.001).

CONCLUSIONS: The results of this nine-year retrospective analysis on the distribution of HCV genotypes and subtypes in 3,655 HCV-infected individuals from Croatia showed that the majority of infections can be attributed to genotypes 1 and 3 with absence of major changes in the molecular epidemiology of the two most frequent HCV genotypes infection in Croatia in the past 20 years.