2.1
Hepatitis C is an infectious disease of the liver caused by the hepatitis C virus (HCV). The virus is acquired primarily through percutaneous exposure to contaminated blood. People infected with HCV are often asymptomatic, but about 20% develop acute hepatitis. In approximately 80% of people who are infected, the virus is not cleared and they go on to develop chronic hepatitis C. Chronic hepatitis C is categorised as mild, moderate or severe depending on the extent of liver damage. The rate of progression from mild to severe disease is slow but variable, taking about 20 to 50 years from the time of infection. About 30% of infected people develop cirrhosis within 20 to 30 years, and some of these develop hepatocellular carcinoma. Some people with end-stage liver disease or hepatocellular carcinoma may require liver transplantation.