Age and gender distribution of hepatitis C virus genotypes in the metropolitan area of Naples.

OBJECTIVE To assess any time-related variations in the distribution of hepatitis C virus (HCV) genotypes in the metropolitan area of Naples, Italy. METHODS HCV genotypes were analysed in 255 HCV RNA-positive patients with chronic HCV infection, observed from 2009 to 2011, and compared with data pertaining to a sample of 176 HCV RNA-positive patients observed from 2006 to 2008. RESULTS In both periods of analysis, genotype 1b was predominant (51.8 and 48.3%, respectively), followed by genotype 2 (27.9 and 31.7%, respectively). These HCV genotypes were particularly prevalent in older patients, whereas genotypes 3a and 1a were observed more frequently in the younger population. Genotype 1b was particularly common in females compared to males in both study periods (39.3% of 89 males vs. 64.3% of 87 females in the 3-year period 2006-2008, p < 0.001; 41.5% of 118 males vs. 54.0% of 137 females in the period 2009-2011, p < 0.05). The prevalence of patients with genotype 1b in the age range 51-60 years was higher in the 2006-2008 period than in 2009-2011 (76.9 vs. 37.7%; p < 0.0005) and lower in the over 60 year olds (55.1 vs. 59.6%; p = 0.5). CONCLUSION Genotype 1b, historically the most prevalent in Italy, is still predominant; however, when comparing the two time periods, a cohort effect evidencing the increasing prevalence of genotype 1b among elderly patients was revealed.