Hepatitis C virus in the new era: Perspectives in epidemiology, prevention, diagnostics and predictors of response to therapy

Abstract

Despite the great successes achieved in the fields of virology and diagnostics, several difficulties affect improvements in hepatitis C virus (HCV) infection control and eradication in the new era. New HCV infections still occur, especially in some of the poorest regions of the world, where HCV is endemic and long-term sequelae have a growing economic and health burden. An HCV vaccine is still no available, despite years of researches and discoveries about the natural history of infection and host-virus interactions: several HCV vaccine candidates have been developed in the last years, targeting different HCV antigens or using alternative delivery systems, but viral variability and adaption ability constitute major challenges for vaccine development. Many new antiviral drugs for HCV therapy are in preclinical or early clinical development, but different limitations affect treatment validity. Treatment predictors are important tools, as they provide some guidance for the management of therapy in patients with chronic HCV infection: in particular, the role of host genomics in HCV infection outcomes in the new era of direct-acting antivirals may evolve for new therapeutic targets, representing a chance for modulated and personalized treatment management, when also very potent therapies will be available. In the present review we discuss the most recent data about HCV epidemiology, the new perspectives for the prevention of HCV infection and the most recent evidence regarding HCV diagnosis, therapy and predictors of response to it.

Hepatitis C virus: Why an Enigma?

“…Highly sensitive and specific assays capable of detecting HCV antigens either alone or in combination with antibodies are now available [28,30]. It is thought that these can be used as an alternative to HCV nucleic acid testing for confirmation of screening test result.…”

“…Genotyping may be done to predict the outcome of therapy. It is also advisable to assess the degree of liver fibrosis with either liver biopsy or indirect serum markers to determine the urgency of treatment [27,28]. Various test available for detection of HCV infection and disease are listed in Table 1 Viral diagnostic tests have continuously improved since the first anti HCV assay was made available in 1990.…”

“…These screening assays doesn't indicate whether the infection is acute or past HCV infection [27,28]. The newer assays have high degree of specificity but false positives can occur in pregnant females, patients with immunological or hematological disease or even in population with low risk of infection [28].…”

“…The first step in the detection of HCV infection is to look for the presence of anti HCV antibodies via screening assays [27,28]. These screening assays doesn't indicate whether the infection is acute or past HCV infection [27,28].…”

“…All the patients who test positive by this method should be additionally tested for HCV RNA to confirm the presence of active viremia. Nucleic acid testing for HCV RNA should also be done for non-reactive anti HCV test if the person is immune compromised or there is a history of HCV exposure [27,28].…”