Hepatitis C is a common cause of chronic hepatitis. It is often asymptomatic until manifestations of chronic liver disease occur. Treatment is with direct-acting antiviral drugs; permanent elimination of detectable viral RNA is possible.
(See also Causes of Hepatitis, Overview of Chronic Hepatitis, and Acute Hepatitis C.)
Hepatitis lasting gt; 6 months is generally defined as chronic hepatitis, although this duration is arbitrary.
There are 6 major genotypes of hepatitis C virus (HCV), which vary in their response to treatment. Genotype 1 is more common than genotypes 2, 3, 4, 5, and 6; it accounts for 70 to 80% of cases of chronic hepatitis C in the US.
Acute hepatitis C becomes chronic in about 75% of patients. The Centers of Disease Control and Prevention (CDC) estimates that about 2.4 million people in the US have chronic hepatitis C infection (1). Worldwide, 71 million people are estimated to have chronic hepatitis C (2).
Chronic hepatitis C progresses to cirrhosis in 20 to 30% of patients; cirrhosis often takes decades to appear. Hepatocellular carcinoma can result from HCV-induced cirrhosis but results only rarely from chronic infection without cirrhosis (unlike in chronic HBV infection).
Up to 20% of patients with alcoholic liver disease harbor HCV. The reasons for this high association are unclear because concomitant alcohol and drug use accounts for only a portion of cases. In these patients, HCV and alcohol act synergistically to worsen liver inflammation and fibrosis.