Natural History of HTLV-I Infection: Prospective Follow-up of a Cohort of Blood Donors in Jamaica

Human T-lymphotrophic virus type I (HTLV-I) is endemic in southern Japan and the Caribbean, but disease manifestations differ across geographic regions. Though age, gender, and route of infection may determine the natural history of this infection, the observed geographic differences also may, in part, reflect the distinct genetic background of the host as evidenced by the distribution of human leukocyte antigens (HLA) and the presence of other environmental factors. Studies already completed or ongoing have shown notable differences in incidence and prevalence of HTLV-I associated diseases and underscore the need for comparative studies and analyses in these areas. This prospective new study of blood donors in Jamaica provides us with an opportunity to address many hypotheses regarding HTLV-I transmission and pathogenesis in the Caribbean in comparison with an ongoing cohort study of HTLV-I carriers in Japan. This study will * identify host factors associated with HTLV-I carrier status and HTLV-I pathogenesis. * directly calculate the incidence of HTLV-I associated diseases in this population. * examine the role of HTLV-I in the pathogenesis of other common infectious agents. Approximately 5,000+ blood donors who came to the National Blood Transfusion each year will be screened for HTLV-I serology. Of those who agreed to participate, all HTLV-I carriers and age-, and sex-matched HTLV-I-negatives will be invited to the University of the West Indies clinic for a full study enrollment. Study participants will be given a standardized questionnaire, a full physical examination, and a phlebotomy (25-30 mL), and will be followed every other year for interim health status and additional phlebotomy. All subjects will receive an ophthalmologic examination for detection of uveitis and other ocular diseases. Some subjects will be further referred to a neurologist, hematologist or dermatologist, according to their signs and symptoms. Approximately 1200 HTLV-I carriers and 6