RISK-FACTORS FOR HUMAN T-CELL LYMPHOTROPIC VIRUS TYPE-I AND TYPE-II (HTLV-I AND HTLV-II) IN BLOOD-DONORS - THE RETROVIRUS EPIDEMIOLOGY DONOR STUDY

In the United States, blood donors have been routinely screened for hu man T-cell lymphotropic virus (HTLV) since 1988. HTLV-I and -II seropo sitive blood donors have been identified through confirmatory testing at five participating blood centers and frequency-matched seronegative controls provided information on potential HTLV sociodemographic, par enteral, and sexual risk factors during structured interviews. After a djustment, low educational attainment; accidental needlesticks or cuts ; prior blood transfusion; greater than or equal to 7 sex partners; an d a sex partner from an HTLV-I endemic area were significantly associa ted with both HTLV-I and -II. Gender did not modify the odds ratios (O R) in the final logistic regression models, despite apparent male-fema le differences in gender-specific bivariable analysis. Injection drug use (IDU) or having sex with an IDUs were significant risks for HTLV-I I, but not for HTLV-I. The OR for donors who had IDU sex partners was 20.6 times higher than those who did not. For IDUs, the OR was increas ed 10.5 times over nonusers. Abortion was a significant HTLV-II risk f actor for women. Our findings indicate that IDU and sex with IDUs are important risk factors for HTLV-II transmission, even among low-risk p opulations such as blood donors.