Markedly high seroprevalence of hepatitis B virus infection in comparison to hepatitis C virus and human T lymphotropic virus type-1 infections in selected Solomon Islands populations

To determine the prevalences of hepatitis B virus (HBV), hepatitis C virus (HCV), and human T lymphotropic virus type-1 (HTLV-1) infections in residen ts of the Solomon Islands, we surveyed 1,610 serum samples from 1,113 outpa tients and 497 healthy volunteer blood donors at the Central Hospital in Ho niara, the Solomon Islands. The prevalence of hepatitis B surface antigen ( HBsAg) by radioimmunoassay (RIA) (n = 315, 19.6%) was significantly differe nt from that of antibody to HCV (anti-HCV) by a second-generation enzyme im munoassay (EIA) (n = 4, 0.2%) and antibody to HTLV-1 (anti-HTLV-l) by an EL ISA with Western blot analysis to verify the positivity (n = 49, 3.0%) (P < 0.0001, respectively). There were no significant differences in the preval ences of these markers between outpatients and blood donors. Hepatitis B e antigen (HBeAg) was detected by RIA in 130 (41.3%) of 315 HBsAg-positive sa mples. The distribution of HBsAg subtypes by EIA was 190 adr (60.3%), 111 a yw (35.2%), and 14 (0.4%) other subtypes. The HBeAg prevalence decreased wi th age in all groups for each subtype. There were no significant difference s in the prevalence of HBeAg among HBsAg subtypes. We conclude that HBV inf ection is highly endemic in selected Solomon Islands populations, and that the high prevalence of HBeAg may be associated with the spread of HBV infec tion there.