Hepatitis B virus infection in hemodialysis patients in Japan: Prevalence, incidence and occult hepatitis B virus infection.

Aim: A survey of hepatitis B virus (HBV) infection in hemodialysis (HD) patients was conducted to determine the burden and risk of infection and to suggest preventive measures against HBV infection among HD patients at nine hospitals in Hiroshima, Japan, from 1999 to 2003. Methods: HBV markers were investigated for 1860 HD patients. The prevalence, incidence of HBV and prevalence of occult HBV were calculated. Results: The prevalence of hepatitis B surface antigen (HBsAg) was 2.6%, the positive rate of anti-hepatitis B core (HBc) was 20.6% and that of anti-hepatitis B surface (HBs) was 11.7%. Among 1372 patients who started HD after the approval of erythropoietin in Japan in 1991, the prevalence of HBsAg was 2.1%. The incidence rate of HBsAg positivity was 0/1000 person-years and the incidence of anti-HBc was 0.3/1000 person-years. Among 1812 HBsAg negative patients HBV DNA was detected in two: one case was negative for anti-HBc and anti-HBs, and the other was only positive for anti-HBc. Prevalence of occult HBV was 0.11%. Conclusion: The incidence rate of HBV was much lower than that of hepatitis C virus (HCV) in the same cohort. We supposed that the discrepancy between incidence rate of HBV and that of HCV was caused by the difference of their carrier rates and of their characteristics for persistent infection. So, we concluded that it is prerequisite to grasp the burden of HBV carriers in the group to prevent new HBV infections in HD patients.