Early case-control studies of patients with newly acquired, symptomatic non-A, non-B hepatitis found a significant association between disease acquisition and a history six months prior to illness of blood transfusions, injection drug use, health care employment with frequent exposure to blood, personal contact with others who had hepatitis, multiple sexual partners or low socioeconomic status.Today, HCV is rarely transmitted by blood transfusion or transplantation of organs due to thorough screening of the blood supply for the presence of the virus and inactivation procedures that destroy bloodborne viruses.These techniques are estimated to have prevented 56 transfusion-associated HCV infections per year in the U.S. since 1999, and have lowered the current risk of acquiring HCV via transfused blood products to 1 in 2 million.In the last several years, blood banks have instituted techniques that utilize nucleic acid amplification of the hepatitis C virus, which will detect the presence of virus even in newly-infected patients who are still hepatitis C antibody-negative.o For patients who have new or multiple partners, HIV infection, or high-risk sexual behaviors, it is recommended that they use condoms and exercise caution regarding potential blood exposure to help reduce the chance of HCV infection.In comparison to other viral infections, HCV is more rapidly acquired after initiation of intravenous drug use.Duration of injecting is the strongest single predictor of risk of HCV infection among injection drug users.Studies of injection drug users have demonstrated that the prevalence of HCV infection in them is extremely high, with up to 90% having been exposed.Other Modes of Transmission