Epidemiology of hepatitis C virus infection in American veterans

OBJECTIVE: This study reports the findings of hepatitis C virus (HCV) infection in a large Department of Veterans Affairs Health Care System in suburban Northern California. METHODS: All veterans who had anti-HCV (EIA II) tested during a 6-yr period (7/92 to 6/98) were included in this study. To estimate the seroprevalence of anti-HCV among our population, 126 consecutive bloodborne pathogen exposure accidents were studied. RESULTS: Of 8558 veterans tested for anti-HCV (EIA II), 2985 (35%) veterans were positive with a mean age of 48.4 yr (range, 28-89 yr). Sixty percent were between the age of 41 and 50 yr. Risk factors for HCV infection identified in 409 consecutive veterans were intravenous drug abuse (81%), unknown (11%), blood transfusion (3%), sexual/household contact (2%), transfusion and intravenous drug use (2%), and tattoo (1%). Of 215 consecutive anti-HCV-positive veterans whose sera were tested by polymerase chain reaction, 96% were viremic. The most common HCV genotypes were 1a (50.5%), 1b (22.8%), 3a (12.1%), 2b (9.7%), 2a (1.9%), undetermined (1.9%), and mixed infection (1%). Veterans infected with genotype 1b were significantly older. Among 126 consecutive bloodborne pathogen exposure accidents, hepatitis C serology was available for 72 index veterans involved in the accidents and 18% were positive. CONCLUSIONS: We found the epidemiology of hepatitis C infection was different in the veteran population when compared to other published data on nonveterans. Hepatitis C infection was much more common among veteran, within a very narrow age distribution and intravenous drug use was the major risk factor.