HTLV-1 infection is endemic in Japan, South America, Northern Oceania, and Tropical Africa and in the Caribbean ocean. Few foci of infection have also been documented in Asia in Philippines. HTLV-1 is transmitted from mother to child through breast milk during the act of breast feeding or during child birth. In adults, transmission is primarily through sexual contact. Apparently, a prolonged period of sexual contact is necessary for transmission of the disease. Homosexual contact, however, appears to play less important role in transmission of the disease. Blood transfusion and intravenous drug abuse are also other very important modes of transmission of HTLV-1.