HTLV TYPE-I AND HTLV TYPE-II INFECTION AMONG INDIANS AND NATIVES FROMARGENTINA

Endemic foci for HTLV-II infection have been identified in several Ame rindian populations. To determine HTLV-I and/or HTLV-II infection amon g Amerindians living in Argentina we studied 454 sera or plasmas from Indians and natives from different areas of our country. All samples w ere tested by the particle agglutination technique, and positive react ions were confirmed by the immunofluorescence assay (IFA). IFA titrati on was used to differentiate HTLV-I and HTLV-II antibodies. Twenty-thr ee of 222 samples (10.4%) were found positive among the Tobas Indians; 22 samples were typed as HTLV-II and 1 as HTLV-I. Antibodies for HTLV -I were found in the serum and CSF of three natives from Salta with a TSP diagnosis. No positive samples were found among 96 Mapuche Indians and 133 natives from San Luis. Our results indicate that HTLV-II is e ndemic among the Tobas Indians. In this study, infection by these retr oviruses in Argentinian Amerindians seems to have a marked geographic distribution.