The HCV is a single-stranded RNA flavivirus.7 There are six numbered genotypes with several different subtypes. The predominant genotype in the U.S. is type 1. The HCV is transmitted primarily through large or repeated percutaneous exposure to infected blood. The most important mode of transmission is needle sharing among IV drug users. After a needlestick or sharps exposure to HCV-positive blood, the risk of HCV infection among HCP is approximately 1.8%.
Most patients (60-75%) with acute HCV infection are asymptomatic (acute symptoms are similar to those associated with HBV infection). About 15% to 25% of persons with HCV infection clear the virus from their bodies without treatment and do not develop chronic infection. However, about 75 to 85% of infected persons develop chronic liver disease (e.g., chronic active hepatitis, cirrhosis, and hepatocellular carcinoma).
There are no vaccines available for the prevention of HCV infections and immunoglobulin has not been shown to prevent acute HCV infection.
The mainstay of treatment for both acute and chronic HCV infections has, until recently, been pegylated interferon and ribavirin, and the possible addition of boceprevir (Victrelis™) and telaprevir (Incivek™). Newer drugs, such as sofosbuvir (Sovaldi™) and simeprevir (Olysio™), in combination antiviral regimens achieve virologic cure (absence of detectable HCV RNA) in 80%-95% of patients after 12-24 weeks of treatment.