"HCV infection in IDUs [intravenous drug users] is acquired primarily through injecting with an infected needle and syringe, which has been used by someone else who is infected with HCV or possibly has become contaminated through contact with other contaminated injecting paraphernalia. The probability of becoming infected after using an infected syringe ranges from 1.5 to 5 per cent for HCV, in contrast to 0.34 to 1.4 per cent for HIV (Vickerman et al., in press)."
Source
Advisory Council on the Misuse of Drugs, "The Primary Prevention of Hepatitis C Among Injecting Drug Users," (London, England: February 2009), p. 12.