Prevalence of antibodies to human T-cell leukemia/lymphoma virus type I and human immunodeficiency virus in Japanese immigrant colonies in Bolivia and Bolivian natives.

This study was performed to estimate human T-cell leukemia-lymphoma virus type-I (HTLV-I) infection and human immunodeficiency virus (HIV) infection in Japanese immigrant colonies in Bolivia, where no seroepidemiological study of HTLV-I or HIV has ever been reported, among 647 healthy adults and children of Japanese descent and Bolivian natives living in the same colonies. The overall prevalence of HTLV-I antibody was 12.6% (59/469) among Japanese immigrant populations, but increased with age, being 16.2% (49/303) among adults and 6.0% (10/166) among children; no significant difference in relation to sex was noted. The first generation immigrants (issei) from Kyushu, the large southwestern island of Japan where adult T-cell leukemia (ATL) is endemic, had 19.0% (49/258) HTLV-I seroprevalence, while issei from outside Kyushu had none (0/39). Among Bolivian members of the community, consisting mostly of Indians and persons of Spanish descent, the HTLV-I seroprevalence was 4.3% (7/164) overall, 2.4% (1/42) among adults and 4.9% (6/122) among children. No antibody to HIV was detected among Japanese or Bolivian populations. The results of this study show that: (1) there is a considerable number of HTLV-I carriers among Japanese immigrant populations in Bolivia, especially among immigrants from Kyushu, (2) there exist some HTLV-I carriers among Bolivian natives, raising the possibility of HTLV-I transmission by co-habitation with Japanese immigrants, (3) HIV is far from endemic in this district of Bolivia, at present.