U.S. Human immunodeficiency virus type 1 epidemic: date of origin, population history, and characterization of early strains.

Human immunodeficiency virus (HIV) type 1 subtype B sequences (whole envelope and the p17 region of gag) were obtained from peripheral blood mononuclear cell samples collected in 1981 from seven HIV-infected U.S. individuals and in 1982 from one infected Canadian resident. Phylogenetic and nucleotide distance analyses were performed by using database… CONTINUE READING