Epidemiological pattern of hepatitis C virus genotypes over a three-year hospital-based survey in northern Italy

Background: hepatitis C virus (HCV) infection is one of the major public health burdens with 71 million people chronically infected worldwide. Persistent HCV infection causes liver cirrhosis, hepatocellular carcinoma, and death. The efficacy, duration, and costs of therapies are strictly dependent on HCV genotype. Considering that in Italy 1.4 million people are infected by HCV, this study investigates the HCV genotype pattern over three years (2013-2015) in the area of Parma (Northern Italy).Materials/methods: serum/plasma samples from 825 individuals attending the University Hospital of Parma were subjected to HCV RNA quantification by COBAS AmpliPrep/COBAS TaqMan HCV v2.0 assay (Roche Diagnostics GmbH) and genotyped by VERSANT HCV Genotype 2.0 LiPA assay (Siemens Healthcare Diagnostics Inc.) Results: of the 825 subjects examined, 454 were males (55%; median age: 51 years), 371 females (45%; median age: 65 years), 738 (89.5%) Italians, and 87 (10.5%) non-Italian, mostly from Eastern Europe (59.8%) and Africa (19.5%). HCV genotypes 1, 2, 3, 4, and 6 were found with decreasing prevalence (51.4%, 22.9%, 17.4%, 8.2%, and 0.1%, respectively), and subtypes 1b (34.7%), 3a (16.7%), and 1a (16.5%) prevailed. In particular, among foreigners, subtypes 1b, 3a, 1a, 4a/4c/4d, 2a/2c, 4 not-subtypable (n-s), 2 n-s, 2b, and the unusual 4e and 6 n-s were found (49.4%, 21.8%, 8.1%, 8.1%, 3.5%, 3.5%, 2.3%, 1.1%, 1.1%, and 1.1%, respectively). Subtypes 1a and 3a predominated in males (P<0.0001). Subtype 1a prevailed in subjects under 61 years old (P<0.0001), while 3a in subjects under 31 years old (P<0.05). Subtypes 1b, 2a/2c, and 2 n-s prevailed in females (P<0.0001, P<0.05, and P<0.005, respectively) and subjects older than 60 years (P<0.0001). Subtype 1b prevalence increased during the study period, contrarily to subtypes 1a and 3a (P<0.05). Higher viremic HCV RNA titres were found in males infected with subtypes 2a/2c, 4a/4c/4d, and 4 n-s. Conclusions: different HCV genotypes were observed in the area of Parma and subtypes 1b, 3a, and 1a prevailed. Less-represented genotypes, such as 4 and 6, may become more frequent due to increasing globalization and migratory flows from endemic areas. Large molecular epidemiological studies help to better understand HCV circulation and improve preventive strategies.