- The hepatitis C virus (HCV) is the leading cause of chronic liver disease and the leading indication for liver transplantation in the United States.
- In the United States, 3.9 million people have been infected with HCV, with an overall prevalence of 1.8%. In females, prevalence is highest during the childbearing years, peaking at age 35.
- Injection-drug use accounts for 60% of infections, while the transfusion of blood or blood products accounts for another 10%.
- About 15% of people with acute HCV infection clear the virus; the rest develop chronic infection.
- During chronic infection, most patients are asymptomatic or have mild, nonspecific symptoms such as fatigue.
- Combination therapy with interferon alpha and ribavirin elicits a sustained virologic response rate of 40%, and newer therapy with pegylated interferon alpha and ribavirin improves the rate to 54%.
- Perinatal transmission in women with chronic HCV infection occurs at an average rate of 5%.
The hepatitis C virus (HCV) was first identified in 1989 as the cause of non-A, non-B hepatitis infections. Since its discovery, HCV has become the most common chronic blood-borne infection in the United States: Approximately 2.7 to 3.5 million people have chronic HCV infection,1,2 as compared with 1.25 million people with chronic hepatitis B virus infection and 1 million with the human immunodeficiency virus (HIV). In addition, HCV infection is the leading cause of chronic liver disease and the leading indication for liver transplantation in the United States. Some call HCV infection “the silent epidemic,” since 75% of people infected are asymptomatic and chronic manifestations don’t appear for 1 to 2 decades.
In 1998, the Centers for Disease Control and Prevention (CDC) issued guidelines for screening for HCV infection ( Table 1).3 The American College of Obstetricians and Gynecologists (ACOG) advocates screening for HCV infection at the annual exam if the patient belongs to one of the CDC’s routine-screening categories.4 Although ACOG has not issued separate screening guidelines for obstetric patients, some practitioners have advocated screening based on risk factors, as listed in the CDC’s routine-screening categories.5
HCV accounts for about 20% of acute hepatitis cases in the U.S.
Because Ob/Gyns are increasingly likely to encounter patients with positive HCV blood-screening results, they should be prepared to answer the following inquiries: What is hepatitis C? How is it diagnosed and transmitted? What is the natural history of the infection? Is there a treatment for it? How will HCV infection affect pregnancy?
This review addresses those questions.
What is hepatitis C?
Hepatitis C is a liver disease caused by the HCV, an RNA virus of the Flavivirus family, which includes the dengue and yellow fever viruses. Worldwide, approximately 170 million people are infected with HCV, with a prevalence ranging from a low of 0.15% in Scandinavia to a high of 38% in northern Egypt.6,7 In the United States, 3.9 million people have been infected with HCV, with an overall prevalence of 1.8%.1 U.S. prevalence rates by gender and age reveal that more males are infected than females and that, in females, prevalence is highest during the childbearing years, peaking at age 35.
Recommendations for hepatitis C virus screening
|PEOPLE WHO SHOULD BE TESTED ROUTINELY|
|PEOPLE FOR WHOM ROUTINE TESTING IS OF UNCERTAIN NEED|
|PEOPLE FOR WHOM ROUTINE TESTING IS NOT RECOMMENDED*|
|* Except in cases where risk factors are present ALT=alanine aminotransferase; HCV=hepatitis C virus|
|Source: Centers for Disease Control and Prevention|
How is HCV infection diagnosed?
The initial screening test is an enzyme immunoassay (EIA) for the antibody to HCV. Currently, a third-generation EIA is used, with a sensitivity and specificity of 99% in immunocompetent people. If the EIA is positive, the practitioner may proceed to a confirmatory recombinant immunoblot assay (RIBA) in individuals with a low pretest probability, or to direct measurement of HCV RNA by reverse-transcription polymerase chain reaction (PCR) in individuals with a high pretest probability. Figure 1 depicts the HCV testing algorithm recommended by the CDC.