Mortality among inhabitants of an HTLV-I endemic area in Japan.
A community-based cohort study was conducted to clarify the risk of human T-cell leukemia virus type I (HTLV-I) infection for cause-specific deaths. A total of 1,997 individuals (751 men and 1,246 women) aged 30 or older in A-Island, Nagasaki Prefecture, Japan who had voluntarily attended annual mass health examinations, including serum HTLV-I antibody test, were followed up for a mean period of 5.3 years. In a Cox proportional hazards analysis adjusted for age at baseline, the HTLV-I seropositivity was found to be associated with mortality from all causes in men (hazard ratio (HR) 1.89; 95% confidence interval (CI) 1.01-3.54) and women (HR 1.94; 95% CI 1.16-3.22). When the effects of 2 deaths (1 man and 1 woman) from adult T-cell leukemia/lymphoma (ATL) were excluded, the mortality risk decreased slightly but was still significantly or marginally significantly greater than 1 in both men (HR 1.77; 95% CI 0.93-3.37) and women (HR 1.87; 95% CI 1.12-3.12). Further analysis of cause-specific deaths revealed a significant increase in the risk for non-neoplastic diseases but not for neoplasms excluding ATL. These findings suggest that long-term HTLV-I infection represents a health hazard greater than just that for the development of ATL. It was difficult, however, to draw a conclusion regarding the association between HTLV-I infection and cancer risk, because the number of cancer deaths was small and the incidence of cancer was not investigated.
Iwata
K
K
Department of Preventive Medicine and Health Promotion, Nagasaki University School of Medicine.
Ito
S
S
Saito
H
H
Ito
M
M
Nagatomo
M
M
Yamasaki
T
T
Yoshida
S
S
Suto
H
H
Tajima
K
K
D000328:Adult; D000368:Aged; D002353:Carrier State / Q000453:epidemiology* / Q000276:immunology; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D015481:HTLV-I Antibodies / Q000097:blood; D015490:HTLV-I Infections / Q000401:mortality*; D015368:Human T-lymphotropic virus 1 / Q000276:immunology*; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors
D015481:HTLV-I Antibodies