A cluster of human T-lymphotropic virus type-I carriers found in the southern district of Tokushima Prefecture.

Since we had experience of eight patients with adult T-cell leukemia lymphoma from 130 cases of non-Hodgkin's lymphoma between 1978 and 1986, a sero-epidemiological survey of anti human lymphotropic virus type-I (HTLV-I) antibody was performed using a gelatin particle agglutination test, an enzyme-linked immunosorbent assay and an indirect immunofluorescence assay for 2,190 adults (768 men and 1,422 women) aged between 21 and 86 years, in the southern district of Tokushima Prefecture. The inconclusive data obtained using the above mentioned methods have been re-examined by western blotting analysis using enzyme-labelled anti IgM and anti IgG. There was an overall prevalence rate of 6.0% (132/2, 190) but higher rate were found in village C (10.9%) and village D (14.2%). These two villages together with town K (6.1% seropositive) form one community unit with a small population in a mountain area, which could be prone to producing a cluster of HTLV-I carriers. Town G with 8.0% sero-positivity is on the Pacific Ocean coast neighboring one of the endemic areas in the eastern section of Kohchi Prefecture. Interestingly, only IgM antibody was detected in 17 of 137 carriers (13%), all females who had never had a blood transfusion, suggesting them to h ave been in a sort of immunodeficient state, as reported in cases of HTLV-I infection. In 13 of 29 HTLV-I carriers (44.8%) from villages C and D, the viral antigen was detected in 1-9% (0.41 +/- 0.19%) of the peripheral blood mononuclear cells after being cultured with phytohemagglutinin for three days. The data indicate that those carriers had evidently been infected with the HTLV-I virus.