HCV genotypes in Northern Italy: a survey of 1368 histologically proven chronic hepatitis C patients

Background/Aims: Hepatitis C virus (HCV) easily undergoes genomic changes, thus accounting for the presence of different genotypes, with different geographic distributions and different outcomes of chronic hepatitis. Type Ib is frequently found in advanced diseases; however, since this genotype is the most prevalent in older patients, the association with advanced age and severity of the disease is confounding. The aim of this study was to assess changes in the prevalence of HCV genotypes by surveying a large population of chronic hepatitis C patients in Northern Italy, and to assess if the high prevalence of genotype Ib in older patients with advanced diseases simply reflects the duration of HCV infection, rather than intrinsic biological properties of HCV. Methods: We studied 1368 HCV-RNA positive patients, with histologically proven chronic hepatitis. Drug addiction, blood transfusions and sporadically acquired infections represented the risk factors. Results: Genotype Ib, the most prevalent isolate, and genotype 2a were associated with older age, cirrhosis, sporadically-acquired infections and blood transfusion, while types la, 3a, and 4 mere associated with younger age, chronic persistent hepatitis and drug addiction. Patients with a history of transfusions were divided into four groups depending on the period of transfusion. The prevalence of genotype Ib decreased with time. Type 3a appeared only after 1979. Conclusion: The severity of chronic hepatitis C could be related more to the duration of the infection Father than to the intrinsic pathogenicity of HCV genotypes.