Objective:The aim of this study was to document which genetic subtypes of HIV-1 have entered Sweden and to study transmission patterns of these virus variants.Patients:All HIV-1-infected individuals at Danderyds Hospital, Stockholm, Sweden, who were suspected of carrying a virus of African origin were prospectively included in the study. The study subjects originated from 15 different African countries.Methods:The V3 domain of the HIV-1 envelope was directly sequenced from uncultured peripheral blood mononuclear cells from 75 individuals included in the study. Phylogenetic analyses were used to determine genetic subtype and to study transmission patterns.Results:The virus strains carried by the study subjects belonged to six established subtypes of HIV-1 (27A, 4B, 18C, 18D, 2G, 2H). Two individuals from Zaire carried a subtype, which had not been classified previously, provisionally named subtype J. Eleven transmissions of non-subtype B strains in Sweden were documented.Conclusions:This study shows that most genetic HIV-1 subtypes have entered Sweden despite the relatively low prevalence of HIV infection in the country. Thus, the complete dominance of subtype-B infections which was seen during the early phase of the HIV-1 epidemic in Europe and the US has been broken in Sweden.