Human T-cell Lymphotropic Virus (HTLV) is a group of viruses that can infect T-cells, a type of white blood cell important for the immune system. There are several types of HTLV, with HTLV-1 and HTLV-2 being the most studied. HTLV-1 is associated with certain diseases, including adult T-cell leukemia and tropical spastic paraparesis. HTLV is primarily transmitted through blood, sexual contact, and from mother to child during childbirth or breastfeeding. It is more prevalent in specific regions, such as parts of Japan, Africa, and the Caribbean. Regular screening and awareness are important for managing the virus and its associated health risks.