Evolving Trends in the Hepatitis C Virus Molecular Epidemiology Studies: From the Viral Sequences to the Human Genome.

Abstract

HCV represents a major worldwide public health problem. The search for the key molecular biomarkers that may provide insight on the basis of the differences in disease progression, severity and response to therapy is crucial for understanding the natural history of HCV, for estimating the burden of infection, and for developing preventive interventions. Initially, molecular epidemiology studies have focused in studying the viral genetic diversity (genotypes, genetic variants, specific nucleotide and amino acid substitutions). However, the clinical heterogeneities of HCV infection and the imperfect predictability of the response to treatment have suggested the need to search for host genetic biomarkers. This led to the discovery of genetic polymorphisms playing a major role in the evolution of infection, as well as on treatment response and adverse effects, such as IL-28B, ITPA, IP-10, etc. As a consequence, nowadays the focus of molecular epidemiology studies has turned from the viral to the human genome. This review will cover recent reports on the subject describing the most relevant viral as well as host genetic risk factors analyzed by past and current HCV molecular epidemiology studies.