Evaluation of Morbidity among Human T Lymphotropic Virus Type I Carriers in Miyazaki, Japan

Morbidity associated with human T lymphotropic virus type I (HTLV-I) infection was investigated in a Japanese population within an area in which HTLV-I infection is endemic. Of 1824 subjects enrolled in the Miyazaki Cohort Study between November 1984 and May 1991, 500 (27.4%) were seropositive for HTLV-I antibodies. As expected from previous studies, HTLV-I positively appeared to be associated with baseline history of anemia (adjusted odds ratio [OR]= 1.3; 95% confidence interval [CI]= 0.99-1.7) and kidney disease (OR=1.6; 95% CI= 0.91-2.9); a positive association also was noted for asthma in men (OR=3.4; 95% CI=1.2-9.8). Unanticipated findings included a relationship between HTLV-I infection and cardiac disease history (OR=1.4; 95% CI=0.94-2.2; HTLV-I carriers also were more likely to have an abnormal electrocardiogram at baseline (OR=1.5; 95% CI=1.2-1.9). Furthermore, an apparent protective effect for ulcers (OR=0.62; 95% CI=0.40-0.95) and diabetes (OR=0.49;95% CI=0.22-1.1) was observed. HTLV-I infection may modify the risk of specific disease outcomes by altering host immune function.