Characterization of HCV genotype 4d infections in Kayseri, Turkey.

BACKGROUND/AIM The frequency of genotype 4 hepatitis C virus (HCV) infections is significantly higher in Kayseri compared to other provinces in Turkey. We aimed to characterize genotype 4 infections in Kayseri by analyzing the demographic and laboratory data of218 HCV RNA-positive, treatment-naive patients admitted to the Kayseri Training and Research Hospital in 2010 and 2011. MATERIALS AND METHODS The distributions of sex, age, and viral loads of these patients with respect to HCV genotypes were analyzed. We also characterized the type 4 sequences at the subtype level. Randomly selected sera from 32 of the 72 genotype 4 patients from this cohort were subjected to PCR amplification in the NS5B region and further characterized by sequencing and phylogenetic and molecular clock analysis. RESULTS Distribution rates of HCV genotypes 1, 4, and 2 in the 218 patients were 62.4%, 33.0%, and 4.6%, respectively. Most of the patients infected with types 1 and 4 were over the age of 40 and female. The NS5B sequences of 32 Kayseri genotype 4 isolates were closely related with type 4d sequences but formed a separate cluster. CONCLUSION The introduction of type 4d HCV into the Kayseri region probably took place 30-75 years ago, as predicted by molecular clock analysis.