[Determination of hepatitis C virus genotype distribution in Mersin province, Turkey]

Hepatitis C virus (HCV) is a member of the Flaviviridae family and the RNA genome e x hibit high genetic heterogeneity. Six major genotypes were phylogenetically determined and each genotype contains different subtypes. The distribution of HCV genotypes varies geographically throughout the world. Determination of viral genotype has great importance in the selection of antiviral therapy, treatment duration and monitoring the response to treatment. The aim of this study was to determine the distribution of HCV genotypes in Mersin province located at the Southern part of Turkey. A total of 236 patients (137 females, 99 males; mean age: 53.28 ± 14.99 years) with chronic HCV infection who were admitted to Mersin University Hospital Microbiology Laboratory during March 2010-May 2012 period were included in the study. The patients were anti-HCV (ELISA; Abbott Laboratories, USA) and HCV-RNA (Cobas TaqMan 48, Roche Diagnostic, USA) positive. HCV genotype analysis was determined by using a commercial LiPA kit (Line Probe Assay; AMPLIQUALITY HCV-TS; AB Analitica, Italy) based on the reverse hybridization of amplification products of viral 5'-UTR region. Out of the 236 patients, genotype 1b was observed in 84.7% (n= 200), genotype 3a in 4.2% (n= 10), genotype 1 in 3.8% (n= 9), genotype 1a/1b in 2.1% (n= 5), genotype 4a in 2% (n= 2), genotype 1a in 1.7% (n= 4), genotype 2b in 1.3% (n= 3), genotype 2 in 0.4% (n= 1), genotype 2a/2c in 0.4% (n= 1) and genotype 6 in 0.4% (n= 1). In the cases infected with genotype 1b, statistically significant differences were detected between gender distribution with the mean serum ALT (46.14 IU/L in females, 63.9 IU/L in males; p= 0.029) and HCV-RNA (634 x 103 IU/L in females, 20 x 105 IU/L in males; p= 0.005) levels. This was the first study that reflected the distribution of HCV genotypes in southern Turkey region. Genotype 1b, associated with poor prognosis and which had the highest prevalence in Turkey, was also determined as the most common genotype with a rate of 84.7% in our region. In addition, low rates of genotype 1a, 2b, 3a and 4a which were identified with low frequency in our country and newly introduced genotype 6 were also demonstrated.