* * *
(HIV) either of two species of the genus Lentivirus (HIV-1 and HIV-2), which cause the acquired immunodeficiency syndrome (AIDS). HIV-1, which comprises at least three subgroups (M, N, and O), is of worldwide distribution, while HIV-2 is largely confined to West Africa. Transmission and manifestations are similar for both. HIV-1 was formerly called human T-cell lymphotropic v. type III and lymphadenopathy-associated v. See Plate 49.Medical dictionary. 2011.