Neuroepidemiology of Human T-Cell Lymphotropic Virus-I

摘要

Human T-cell leukemia virus-I (HTLV-I) has been shown to be the etiologic agentof an aggressive form of leukemia/lymphola and a chronic neurologic syndrome called HTLV-I associated myelopathy/tropical spastic paraparesis (HAM/TSP). This chapter focuses on the neurologic syndrome, describing the history, epidemiology, and clinical presentation of HAM/TSP. Although the clinical entity of TSP was described in the late 1960's, it wasn't until 1985 that HTLV-I was shown to the etiologic agent for the sporadic form of this disease. HAM/TSP is found in HTLV-I endemic areas which include southern Japan, the Caribbean basin, and parts of Central and South America. HAM/TSP can occur in the setting of perinatal, sexual, or parenteral transmission of HTLV-I infection with a prolonged incubation period up to several years. The risk of disease expression in HTLV-I infected carriers is not known, but appears to be low. Clinically, patients present with chronic, progressive spasticity, predominately of the lower extremities with demyelination of the spinal cord and it is proposed to be an autoimmune disorder. Identification of an infectious etiology has exciting implications not only for HAM/TSP but also provides further impetus to investigate the etiologies of other neurologic disease processes such as multiple sclerosis.