Hepatitis C is a blood-borne infectious disease that is caused by Hepatitis C virus (HCV), infecting the liver.[1] The infection can cause liver inflammation (hepatitis) that is often asymptomatic, but ensuing chronic hepatitis can result later in cirrhosis (fibrotic scarring of the liver) and 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 long course of anti-viral medicines. Although early medical intervention is helpful, people with HCV infection often experience mild symptoms, and consequently do not seek treatment.[1] An estimated 150-200 million people worldwide are infected with hepatitis C.

http://en.wikipedia.org/wiki/Hepatitis_C