Diagnosis and treatment of chronic hepatitis C infection

Hepatitis C virus was identified in 1989 as a major cause of the parenterally transmitted non-A non-B hepatitis. Chronic hepatitis C virus infection affects an estimated 170 million people worldwide1 and is characterised by varying degrees of inflammation and hepatic fibrosis. A proportion of patients with chronic infection will develop progressive liver damage with cirrhosis and complications of end stage liver disease over 20 to 40 years. Chronic infection is now the leading indication for liver transplantation in developed nations and will continue to pose an important health and economic burden during the next 10 to 20 years. Here we outline the criteria for screening, diagnosing, and treating patients with hepatitis C virus infection and describe potential future therapies. Hepatitis C virus (see bmj.com for description of virus) is transmitted by parenteral or permuscosal exposure to infected blood or body fluids. Many patients will give a history of injecting drug use or transfusion of blood products before the implementation of antihepatitis C virus screening of blood donors in 1992. Seroprevalence among injecting drug users is more than 80%, and this remains a major risk factor for newly acquired hepatitis C virus infection in the developed world. Community based strategies for prevention of infection in these high risk groups are needed urgently but depend on resources (box 1). Screening of volunteer blood donations in developed nations has significantly reduced transfusion related hepatitis. Most countries in the developing world do not, however, have adequate screening procedures, and only about 40% of donated blood is tested for the virus. Occupational, vertical, and sexual transmission account for only a minority of new cases of hepatitis C virus infection. Sexual transmission of hepatitis C virus among monogamous partners is rare, but testing is often carried out for reassurance (box 2). See bmj.com for contact …