Prevalence and incidence of hepatitis C virus infection in the US military: A seroepidemiologic survey of 21,000 troops

Because of a high prevalence of hepatitis C virus (HCV) infection (10-20%) among veterans seeking care in Department of Veterans Affairs (VA) hospital s, current US military forces were evaluated for HCV infection. Banked seru m samples were randomly selected from military personnel serving in 1997 an d were tested for antibody to HCV (anti-HCV). Overall prevalence of anti-HC V among 10,000 active-duty personnel was 0.48% (5/1,000 troops); prevalence increased with age from 0.1% among military recruits and active-duty perso nnel aged <30 years to 3.0% among troops aged <greater than or equal to>40 years. Prevalence among 2,000 Reservists and active-duty troops was similar . Based on sequential serum samples from 7,368 active-duty personnel (34,02 0 person-years of observation), annual incidence of infection was 2/10,000. Of 81 HCV RNA-positive troops for whom genotype was determined, genotypes 1a (63%) and 1b (22%) predominated, as in the civilian population. These da ta indicate that HCV infection risk among current military forces is lower than in VA studies and the general civilian population aged <40 years. The low level of HCV infection may be attributed to infrequent injection drug u se in the military due to mandatory testing for illicit drugs prior to indu ction and throughout military service.