Infectious states of human T lymphotropic virus type I and hepatitis B virus among Japanese immigrants in the Republic of Bolivia.

Serologic tests for human T lymphotropic virus type I (HTLV-I) and hepatitis B virus infections were conducted in 1986 in two Japanese immigrant colonies located in Santa Cruz, Bolivia. A total of 322 adults (283 Japanese and 39 Bolivians) over age 35 years and 305 children (166 Japanese, 124 Bolivians, and 15 of mixed blood) aged 8-17 years were sampled at the time of a routine health checkup. The prevalence of antibody to HTLV-I was 17% in first-generation Japanese immigrants and 6% in second- or third-generation Japanese children. Prevalences among native Bolivians were 3% and 5% in adults and children, respectively. Seropositive Japanese immigrants and mothers showed clustering according to birthplace in endemic areas of Japan. The prevalence of either hepatitis B virus surface antigen (HBsAg) or antibody to HBsAg was 48% in Japanese adults, 21% in Japanese children, 13% in Bolivian adults, and 1% in Bolivian children. Seropositive adults did not show clustering according to birthplace, but children in one colony showed clustering and a narrow age range. A correlation of seropositivity between husbands and wives was found only for HTLV-I. The seropositivity was independent of whether an HTLV-I or a hepatitis B virus infection marker was present.