What is the case definition for acute hepatitis C?
Because the clinical characteristics are similar for all types of acute viral hepatitis, the specific viral cause of illness cannot be determined solely on the basis of signs, symptoms, history, or current risk factors, but must be verified by specific serologic testing. For specific serologic tests required to meet the case definition, see the following link:
What is the case definition for chronic hepatitis C?
Laboratory testing is required for confirmation of the etiologic cause of viral hepatitis. For specific serologic tests, see the following link:
Is additional guidance on viral hepatitis Case determination and surveillance available?
Yes. See the Guidelines for Viral Hepatitis Surveillance and Case Management, available here.
What is the incidence of HCV infection in the United States?
The number of acute cases of hepatitis C reported in the United States increased from, 1,778 in 2012 to 2,138 in 2013. The CDC estimates approximately 29,718 cases occurred in 2013, after adjusting for asymptomatic infection and underreporting.
What is the prevalence of chronic HCV infection in the United States?
3.5 million (range 2.5 million-4.7 million) people are estimated to be currently infected with hepatitis C, according to a 2015 study by Edlin et. al. This figure was derived from the 2003-2010 National Health and Nutrition Examination Survey (NHANES), which estimates about 2.7 million people are currently infected, and from an additional estimate of high risk populations not typically included in this national survey. An additional 800,000 individuals are estimated to be infected, and this number was obtained from a systematic review of peer-reviewed literature and unpublished data, representing prevalence of hepatitis in incarcerated, hospitalized, and homeless individuals; military personnel; individuals on Indian reservations; and nursing home residents.
Who is at risk for HCV infection?
The following persons are at known to be at increased risk for HCV infection:
- Current or former injection drug users, including those who injected only once many years ago
- Recipients of clotting factor concentrates made before 1987, when more advanced methods for manufacturing those products were developed
- Recipients of blood transfusions or solid organ transplants before July 1992, when better testing of blood donors became available
- Chronic hemodialysis patients
- Persons with known exposures to HCV, such as health care workers after needlesticks involving HCV-positive blood or recipients of blood or organs from a donor who tested HCV-positive
- Persons with HIV infection
- Children born to HCV-positive mothers
Is it possible for someone to become infected with HCV and then spontaneously clear the infection?
Yes. Approximately 15%–25% of persons clear the virus from their bodies without treatment and do not develop chronic infection; the reasons for this are not well known.
How likely is HCV infection to become chronic?
HCV infection becomes chronic in approximately 75%–85% of cases.
Why do most persons remain chronically infected with HCV?
A person infected with HCV mounts an immune response to the virus, but replication of the virus during infection can result in changes that evade the immune response. This may explain how the virus establishes and maintains chronic infection.
What are the chances of someone developing chronic HCV infection, chronic liver disease, cirrhosis, or liver cancer or dying as a result of hepatitis C?
Of every 100 persons infected with HCV, approximately
- 75–85 will go on to develop chronic infection
- 60–70 will go on to develop chronic liver disease
- 5–20 will go on to develop cirrhosis over a period of 20–30 years
- 1–5 will die from the consequences of chronic infection (liver cancer or cirrhosis)
Can persons become infected with a different strain of HCV after they have cleared the initial infection?
Yes. Prior infection with HCV does not protect against later infection with the same or different genotypes of the virus. This is because persons infected with HCV typically have an ineffective immune response due to changes in the virus during infection. For the same reason, no effective pre- or postexposure prophylaxis (i.e., immune globulin) is available.
Is hepatitis C a common cause for liver transplantation?
Yes. Chronic HCV infection is the leading indication for liver transplants in the United States.
How many deaths can be attributed to chronic HCV infection?
A recent CDC analysis of death certificate data found that HCV-attributable deaths increased significantly between 1999 and 2007. CDC estimates that there were 15,106 deaths caused by HCV in 2007. The citation can be found at “The increasing burden of mortality from viral hepatitis in the United States between 1999 and 2007.” Ly, K., et al. Annals Of Internal Medicine, 2012. 156(4): p. 271-278
Is there a hepatitis C vaccine?
No vaccine for hepatitis C is available. Research into the development of a vaccine is under way.