The U.S. Centers for Disease Control and Prevention estimates that about 4.1 million persons in the United States have been infected with HCV, and 3.2 million of these people are chronic carriers.
About HCV
Hepatitis C is the most common, chronic blood-borne infection in the United States1 and can cause progressive liver damage that can lead to cirrhosis (liver scarring), hepatocellular carcinoma (liver cancer), liver failure and death.2 The burden of hepatitis C infection on patients and health care systems is expected to continue rising over the next two decades3 due to continued disease progression among many individuals infected prior to 1990. As the prevalence of severe liver disease attributable to chronic hepatitis C infection rises, deaths due to complications from it, which are currently 8,000-12,000 per year in the United States, are expected to increase 180% over the next 20 years.3
Transmission
HCV is most commonly spread by contact with contaminated blood.2 In Western countries, current and former injecting drug users, recipients of unscreened blood products (prior to early 1990s), dialysis patients, and hemophiliacs constitute the highest risk groups for the acquisition of HCV.2 Additional risks for infection include receiving an organ transplant prior to 1992, and lower risks such as unprotected sex with multiple partners, birth from an infected mother, and needle-stick injuries sustained by health care workers.4 In developing countries, primary sources of HCV transmission may also include the use of unsterilized equipment for either medical procedures or other procedures, such as ear/body piercing, circumcision, or tattooing.2
Prevention
Currently, there is no vaccine that can prevent hepatitis C.2 The advent of diagnostic tests for HCV in the early 1990s led to marked improvements in preventing HCV infections, through screening of the blood supply and patient education.5 Diagnostic tests are able to detect the hepatitis C virus in the blood of infected patients.2 These tests are essential tools for identifying patients and managing therapy and have led to a sharp decline in the occurrence of new HCV infections in the United States.2 However, due to the slow progression of HCV after initial infection and to the relatively low rate of spontaneous viral clearance among chronically infected individuals, the prevalence of chronic HCV infection and progressive liver disease remains high.3
Treatment
Current approved treatments in the United States include interferon and pegylated interferon administered by injection alone or in combination with ribavirin.4 The goal of HCV therapy is to achieve a sustained virologic response (SVR). SVR is defined as undetectable HCV six months post treatment. There are several strains of the hepatitis C virus and genotype 1 is the most prevalent and most treatment-resistant strain of the virus in the United States, Western Europe and Japan. Among patients infected with HCV genotype 1 who complete treatment with pegylated interferon plus ribavirin, 42%-46%6,7 achieve an SVR. The need to improve response rates has led to the discovery and development of many investigational products for treatment-naïve patients, as well as the many patients for whom pegylated interferon and ribavirin therapy has failed.8
1 Centers for
Disease Control National Hepatitis C Strategy.
2 World Health Organization. Hepatitis C Fact Sheet
3 Davis, G. et. al. Projecting Future Complications of Chronic Hepatitis C in
the United States. Liver Transplantation 2003; Vol. 9 No.
4:331-338
4 Centers for Disease Control: Fact Sheet
5 Strader, D.B. et. al. Diagnosis, Management and Treatment of Hepatitis C.
AASLD Practice Guideline. Hepatology 2004
6 Fried, M. et. al., Peginterferon Alfa-2A Plus Ribavirin for Chronic
Hepatitis C Virus Infection. New England Journal of Medicine 2002.
7 Manns, M. Peginterferon Alfa-2B Plus Ribavirin Compared with Interferon
Alfa-2B Plus Ribavirin for Initial Treatment of Chronic Hepatitis C; A
Randomized Trial. The Lancet, September 2001.
8 Bernstein, D. et. al. Relationship of Health-Related Quality of Life to
Treatment Adherence and Sustained Response in Chronic Hepatitis C
Patients. Hepatology. 2002. Vol. 35 No. 3