[Prevalence of antibody to adult T-cell leukemia virus in Hokkaido District].

In order to investigate the spread of adult T-cell leukemia (ATL) virus in the inhabitants of ATL-non-endemic Hokkaido, we surveyed the antibodies to ATL-associated antigen (ATLA) in 29516 healthy individuals by indirect immunofluorescence test using MT-1 for target cell. Of the healthy inhabitants, only 219 individuals (0.74%) were anti-ATLA positive as carriers. Prevalence of anti-ATLA was 0.63% (111 of 17590) in males and 0.91% (108 of 11926) in females. This difference by sex is significant. In several regions, the inhabitants were found to show relatively high incidence (greater than 2%) of the antibodies, and these regions have a tendency to cluster around the western side of Hidaka mountains or Akan area. The highest rate (5.2%) of anti-ATLA positive carriers was shown in a certain town of Hidaka area.