Hepatitis C is a blood-borne infectious disease that is caused by the Hepatitis C virus (HCV), affecting the liver. The infection is often asymptomatic, but once established, chronic infection can cause inflammation of the liver (chronic hepatitis). This condition can progress to scarring of the liver (fibrosis), and advanced scarring (cirrhosis). In some cases, those with cirrhosis will go on to develop liver failure or other complications of cirrhosis, including liver cancer.

The hepatitis C virus (HCV) is spread by blood-to-blood contact. No vaccine against hepatitis C is available. The symptoms of infection can be medically managed, and a proportion of patients can be cleared of the virus by a course of anti-viral medicines. Although early medical intervention is helpful, people with HCV infection can experience mild symptoms, and consequently do not seek treatment. An estimated 150-200 million people worldwide are infected with hepatitis C.

Hepatitis C (originally "non-A non-B hepatitis") is one of five known hepatitis viruses: A, B, C, D, and E.

History

In the mid 1970s, Harvey J. Alter, Chief of the Infectious Disease Section in the Department of Transfusion Medicine at the National Institutes of Health, and his research team demonstrated that most post-transfusion hepatitis cases were not due to hepatitis A and B viruses. Despite this discovery, international research effort to identify the virus, initially called non-A, non-B hepatitis (NANBH), failed for the next decade. In 1987, Michael Houghton, Qui-Lim Choo, and George Kuo at Chiron Corporation, collaborating with Dr. D.W. Bradley from CDC, utilized a novel molecular cloning approach to identify the unknown organism. In 1988, the virus was confirmed by Alter by verifying its presence in a panel of NANBH specimens. In April of 1989, the discovery of the virus, re-named hepatitis C virus (HCV), was published in two articles in the journal Science.

Chiron filed for several patents on the virus and its diagnosis. Houghton, M., Q.-L. Choo, and G. Kuo. NANBV Diagnostics and Vaccines. European Patent No. EP-0-3 18-216-A1. European Patent Office (filed 18 November 1988, published 31 May 1989). A competing patent application by the CDC was dropped in 1990 after Chiron paid $1.9 million to the CDC and $337,500 to Bradley. In 1994 Bradley sued Chiron, seeking to invalidate the patent, have himself included as a co-inventor, and receive damages and royalty income. He dropped the suit in 1998 after losing before an appeals court.Paul Elias. ""Hepatitis Drug-Maker Complaints Reviewed", The Associated Press, 27 February 2004