Trends in the seroprevalence of HTLV-1 in Japanese blood donors in Nagasaki Prefecture, 2000-2006.
Human T cell leukemia virus type-1 (HTLV-1) is the established cause of adult T cell leukemia/lymphoma. Monitoring time trends in HTLV-1 seroprevalence in blood donors is important to assess the safety of the blood supply in the viral endemic area. We analyzed changes in HTLV-1 seroprevalence in 48415 first-time blood donors who donated blood from 2000 to 2006 in Nagasaki prefecture, an endemic area in Japan. The donors were divided into 10-year birth cohorts: before 1950, 1951-1960, 1961-1970, 1971-1980, and 1981-1990. Among the first-time blood donors, 622 were tested positive for HTLV-1 [overall seroprevalence: 1.28%, (95% CI 1.19-1.39)]. Seroprevalence was significantly high in the birth cohort of before 1950 (6.22%) and declined with birth-year. The time trend of the birth-cohort-specific seroprevalence showed almost no change within each birth cohort, except for the birth cohort of 1981-1990 that showed a significantly declining trend (P for trend = 0.006). Among the birth cohort of 1981-1990, the seroprevalence was stable among those born during 1981-1986 (0.66-0.83%), but was lower among those born during 1987-1990 (0-0.38%). Detail analyses showed that HTLV-1 seroprevalence among blood donors clearly declined in those born after 1987.
Iwanaga
Masako
M
Department of Hematology and Molecular Medicine, Nagasaki University Graduate School of Biomedical Sciences, 1-12-4 Sakamoto, Nagasaki City, Nagasaki, 852-8523, Japan. masakoiw@nagasaki-u.ac.jp.
Chiyoda
Shin
S
The Nagasaki Red Cross Blood Center, 3-256-11, Showa, Nagasaki, 852-8145, Japan.
Kusaba
Eisuke
E
The Sasebo Red Cross Blood Center, 8-66 Daitoh, Sasebo, Nagasaki, 857-1161, Japan.
Kamihira
Shimeru
S
Department of Laboratory Medicine, Nagasaki University Graduate School of Biomedical Sciences, 1-7-1 Sakamoto, Nagasaki City, Nagasaki, 852-8501, Japan.
D000328:Adult; D000914:Antibodies, Viral / Q000097:blood; D044466:Asian People / Q000706:statistics & numerical data*; D001782:Blood Donors / Q000706:statistics & numerical data*; D015331:Cohort Studies; D019353:Endemic Diseases; D005260:Female; D015490:HTLV-I Infections / Q000208:ethnology* / Q000276:immunology; D015368:Human T-lymphotropic virus 1 / Q000276:immunology*; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D016036:Seroepidemiologic Studies; D055815:Young Adult
D000914:Antibodies, Viral