Definition of Human T-lymphotropic virus type I

Human T-lymphotropic virus type I: (HTLV-I) A virus often referred to simply as the human T-lymphotropic virus (HTLV).

HTLV-II stands for human T-lymphotropic virus type II, which is closely related to HTLV-I.

HTLV-III is now known as the human immunodeficiency virus or HIV.