Natural History of Hepatitis C Infection

Natural history of hepatitis C virus (HCV) infection has been extensively studied in the past, since for several decades, scarcity of potent and effective antiviral treatments allowed observational studies of large untreated cohorts. However, deep understanding of HCV natural history has been always hampered by the asymptomatic course of the disease, both in the acute and in the chronic infection phase. As a consequence, many studies conducted in the field of natural history have prospectively evaluated only selected patients’ cohorts according to presence of HCV risk factors (blood donors, post-transfusion HCV cohorts) that could maximize chance of early diagnosing HCV infection, thus generating data about HCV natural course only in peculiar patient subsets. Less selected data mainly come from retrospective or retrospective-prospective studies where a precise estimate of HCV infection could be done according to patient’s medical history. However, also these data have often been generated in secondary or tertiary centers, so introducing a referral bias as patients referred for treatment were often those with a progressive disease. Despite all these caveats, the natural course of HCV has been extensively characterized both in the acute and in the chronic infection leading to liver disease and its complications [1].