Hepatitis B virus markers in Japanese immigrants and their descendants in Bolivia and native Bolivians.

A survey of hepatitis B virus (HBV) markers of Japanese immigrants, their descendants and native Bolivians was performed in two agricultural settlements in Bolivia. The prevalence of HBV markers in sera, either hepatitis B surface antigen (HBsAg) or its antibody (HBsAb), was higher in the Japanese (46.4%) than in the native Bolivian (12.9%) adult generations of both colonies. There was no significant difference between Japanese (4.3%) and Bolivian (0.9%) school children in one colony, but a high percentage (32.6%) was recognized among Japanese children in the other colony. The numbers of adw subtypes were unexpectedly high among these HBsAg positive Japanese children, compared to those in Japan. Antibody to hepatitis delta virus (HDV) was detected in one case. These data suggested that although horizontal transmission of adw HBV had occurred within the Japanese population, HBV and HDV were not endemic to this geographic area.