Prevalence of Hepatitis C Infection in the General Population in the United States

The hepatitis C virus (HCV) is an RNA virus classified within the Flaviviridae family.(1) Before the characterization of the virus, a diagnosis of viral hepatitis was largely one of exclusion (ie, non-A, non-B hepatitis). Early studies demonstrated that non-A, non-B hepatitis was associated with blood transfusions.(2,3,4) Population-based sentinel surveillance conducted by the Centers for Disease Control and Prevention demonstrated that this disease accounted for 15% to 20% of community-acquired viral hepatitis in the United States.(5) After the virus was cloned in 1988, studies demonstrated that HCV was the primary cause of community-acquired non-A, non-B hepatitis in the United States.(5,6) Data from the Third National Health and Nutrition Survey (1988-1994) estimate that there are approximately 3.9 million non-institutionalized, civilian Americans who have been infected with HCV.(7) Of these, 2.7 million have chronic infection, making HCV the most common chronic blood-borne infection in the United States. Perhaps the majority of those infected are unaware of their infection because they do not currently have signs or symptoms of disease. The highest prevalence of infection is found among those with repeated, direct percutaneous exposures to blood (eg, injection drug users, recipients of blood transfusions from HCV-positive donors, and persons with hemophilia who were treated with clotting factor concentrates before 1987). The estimated prevalence of infection varies greatly among different geographic locations and selected populations in the United States according to the varying prevalence of risk factors for infection.

Prevalence of Hepatitis C Infection in Veterans

The true prevalence of hepatitis C infection among veterans is unknown, but survey data suggest that hepatitis C has a higher prevalence in veterans who are currently using the VA system than in the U.S. population as a whole. Data from the National VA Screening Day in March of 1999 demonstrated that 6.6% of veterans who had blood drawn for other purposes on that day were HCV seropositive(8). In a recent study published by Sloan et al, 37,398 veterans from the VA health care system in the Pacific Northwest were tested for anti-HCV antibodies, and 8,230 (21.7%) were positive.(9) 45.8% of the seropositive veterans were between the ages of 40 and 49 years. The prevalence of anti-HCV among male US shipboard military personnel scheduled for deployment to South America/West Africa and the Mediterranean was approximately 0.4% (9/2072)(10). The prevalence of anti-HCV among a cohort of active-duty US marines stationed in Okinawa, Japan was 0.2% (2/1010).(11) Therefore, the prevalence of antibodies to HCV varies substantially according to the different military populations considered. In general, the prevalence in active duty military personnel appears to be lower than the prevalence in veterans.

References

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