RESUMEN
Human T-cell leukemia virus type I (HTLV-I) carriers are clustered in limited groups in the world. One of these groups is the Andrean native population of South America. As part of an international collaborative study devoted to explore the clustering of HTVL-I carriers in different countries, the aim of this paper was to evaluate the seroprevalence of HTLV-I/II virus in the native population of Puna Argentina in Jujuy. Blood samples of individuals of three populations of Puna Jujeña (Susques, Rinconada, Cochinoca) were screened with particle agglutination (PA), immunofluorescence (IF) and western immunoblotting analysis (WB) tests. Two ou 86 (2.32 por ciento) individuals examined in the Puna Jujeña showed positive results for HTLV-I antibodies. It is concluded that the Province of Jujuy, in particular its less mescegenated highest altitude areas, constitute the northern and southern Andean natural geographical clustering of HTLV-I. This distribution is probably linked both to a history of prehistoric human dispersal in the Andes and to high mother-to-child transmission of the virus under close conditions of each group.