Human T-cell lymphotropic virus type 1 or human T-lymphotropic virus (HTLV-I), also called the adult T-cell lymphoma virus type 1, is a retrovirus of the human T-lymphotropic virus (HTLV) family. Most people with HTLV-1 infection do not appear to develop health conditions that can be directly linked to the infection. However, there is a subgroup of people who experience severe complications...