Hepatitis C is the most common blood-borne infection in the United States. It affects at least 4 million people in the U.S. and 175 million people worldwide.

It is not always clear how a person becomes infected with hepatitis C. However, it is estimated that:

• Between 60% and 90% of people who get hepatitis C are those who have been repeatedly exposed to infected blood. These include injection drug users and people with hemophilia who were treated with blood clotting factor concentrates before 1987.
• Between 10% and 20% of people who have received hemodialysis for kidney problems are infected with hepatitis C.
• Less than 5% of people are infected because of high-risk sexual behavior.
• About 1% of people, such as health care workers, become infected through accidental exposure to infected blood.¹