HCV

Hepatitis C virus (HCV) is a member of the genus Hepacivirus within the Flaviviridae family. It infects hepatocytes in the liver and can cause acute or chronic hepatitis C. Most infections become chronic and may progress over decades to cirrhosis, liver failure, or hepatocellular carcinoma. Some individuals experience extrahepatic manifestations, such as cryoglobulinemia and certain kidney, skin, or rheumatologic conditions.

Transmission occurs primarily through blood-to-blood contact. Major routes include sharing needles or other equipment for intravenous drug use, transfusion of unscreened blood or blood products (before routine screening), and less commonly through sexual contact or vertical transmission from mother to child. Occupational exposure and organ transplantation are additional risk factors in certain settings.

The HCV genome is a positive-sense single-stranded RNA about 9.6 kb in length. It encodes a single polyprotein that is cleaved into structural proteins (core, E1, E2) and nonstructural proteins (NS2-NS5B). High genetic diversity yields several genotypes (1 through 6) and numerous subtypes; genotype historically influenced treatment choices, though modern therapies are effective across genotypes.

Diagnosis usually begins with screening for anti-HCV antibodies, followed by RNA polymerase chain reaction testing to confirm active infection. Assessment of liver fibrosis and overall liver health helps guide management.

Treatment relies on direct-acting antivirals (DAAs), such as combinations including sofosbuvir, ledipasvir, velpatasvir, or glecaprevir/pibrentasvir. Most patients achieve sustained virologic response and are considered cured after 8–12 weeks of therapy. There is no vaccine for HCV; prevention focuses on reducing exposure to infected blood, safe injection practices, safe blood supplies, and harm-reduction strategies, with special attention to coinfections such as HIV or HBV. Global public health efforts aim to increase testing, treatment access, and prevention to reduce incidence and mortality.