I are found with high frequency in persons affected with these disorders. HTLV-I is endemic in the Caribbean, southern Japan, and in some areas of Africa. In the United States, HTLV-I has been identified in ATLL patients, intravenous drug abusers, and in healthy individuals. HTLV-I infection to transfusion recipients of infected cellular blood products is well documented. Other known modes of transmission include breast milk, sexual contact, and sharing of contaminated needles and syringes by intravenous drug abusers.
Perinatal transmission is suspected but remains unproven.
HTLV-II has been rarely isolated from patients with hairy cell leukemia and other conditions. Its role in neoplastic disease is unclear. The life-time risk for TSP is unknown. Its performance characteristics were determined by ARUP Laboratories. Anderson DW, et al.