What is the primary risk factor for infection with hepatitis C virus?

Intravenous drug use is recognized as the primary risk factor for infection with the hepatitis C virus (HCV). This association is largely due to the sharing of needles and other drug paraphernalia among users, which allows for direct blood-to-blood contact. The virus is present in high concentrations in the blood of infected individuals, and sharing needles facilitates transmission.

While transfusion of infected blood is also a significant risk factor, the implementation of rigorous screening practices for blood products has greatly reduced this risk in many regions. Close contact with an infected individual is not a common transmission route for HCV compared to blood exposure, and exposure to contaminated water is not associated with hepatitis C infection. The established mode of transmission underscores the importance of harm reduction strategies and interventions aimed at intravenous drug users to prevent the spread of HCV.