Prevalence of Hepatitis B Virus Exposure in the Veterans Health Administration and Association With Military-Related Risk Factors

Abstract

Military veterans have been reported to have higher odds of hepatitis B virus (HBV) exposure after adjustment for demographic factors, family income, and birthplace. It is not clear whether military-related exposures are associated with risk of HBV exposure in veterans. A random sample of veterans receiving care from 1998 through 2000 in the national Veterans' Health Administration system completed a risk factor survey and underwent phlebotomy analysis (N= 1146). Stored serum samples were reanalyzed to determine prevalence of HBV exposure (core antibody positive), infection (surface antigen or DNA positive), and immunity (surface antibody positive, surface antigen negative, and core antibody negative). Associations between military-related risk factors and HBV exposure were assessed using logistic regression. The prevalence values for infection, exposure, and immunity were 0.7% (95% CI, 0.3-1.5), 13.6% (95% CI, 11.5-16.1), and 6.2% (95% CI, 4.7-8.2), respectively. Evidence of HBV exposure was highest among respondents with traditional risk factors (such as drug use or high-risk sexual practices). More than half the individuals with HBV exposure (53%) reported no history of traditional risk factors; of these, 59.5% reported a history of combat exposure. After adjustment for demographic and traditional risk factors, service in a combat zone (adjusted odds ratio, 1.56; 95% CI, 1.01-2.41) and being wounded in combat (adjusted odds ratio, 1.79; 95% CI, 1.04-3.08) were associated independently with exposure to HBV. In an analysis of US military veterans, we found the prevalence of exposure to HBV to be highest among veterans with traditional risk factors but also independently related to military combat or being wounded in combat. Studies are needed to determine whether veterans with combat exposure before the era of universal vaccination should be screened for HBV exposure.