14. Chronic Viral Hepatitis in Adults and Children: Hepatitis C

Summary

The hepatitis C virus (HCV) is a small, parenterally transmitted RNA virus that is acquired today almost exclusively by the use of unsterile needles. It occurs in sixdistinct genotypes, genotype 1 being the most prevalent in North America, Europe, and Japan. HCV causes an acute hepatitis that is clinically silent in most cases and persists in the majority (80%) of patients leading to chronic hepatitis. Chronic hepatitis C remains clinically silent, and progresses to cirrhosis in about 10% of patients within 20 years. Once cirrhosis is established, morbidity and mortality from hepatic decompensation and hepatocellular carcinoma ensues. Concomitant alcohol consumption, male gender, co-infection with HIV or HBV, and older age at time of infection accelerates the progression to cirrhosis. Non-hepatic manifestations of chronic hepatitis C infection include mixed cryoglobulinemia, which may cause renal failure.

Every new patient should be asked for risk factors of HCV infection including: a history of transfusion of blood and blood products prior to the early 1990s, a history of or present i.v. drug use (or snorting cocaine with a straw), a history of piercings and tattoos and medical procedures performed without appropriate sterile techniques, coming from a high prevalence region of the world, or being born to a mother with HCV infection. Patients with any of these risk factors should be screened by anti-HCV antibody testing; positive test results need to be confirmed by direct detection of circulating virus using an HCV RNA PCR assay.

Antiviral therapy should be considered in every patient with confirmed HCV infection. Patients with HCV infection should be referred for consideration/conduct of antiviral treatment to physicians with expertise and up-to-date knowledge in the field. Therapy of hepatitis C virus infection is rapidly evolving; the current standards consist of pegylated interferon and ribavirin. The addition of new, directly acting antiviral agents improve cure rates. Efficacy of therapy depends on genotype, with cure rates (i.e. sustained virological response) being achieved with current standard therapy in 50% of genotype 1 and 4, and 80% of genotype 2 and 3 infected patients. Side effects of therapy are common and can be severe.

Infants of mothers who have chronic hepatitis C should be tested for hepatitis C infection by checking anti-HCV antibodies, but only after 18 monthsold when a positive test signifies actual infection.