Human alveolar echinococcosis seroprevalence assessed by western blotting in Hokkaido.

To investigate the recent prevalence of human alveolar echinococcosis in Hokkaido, we took advantage of Western blotting analysis capable of classifying persons infected with Echinococcus multilocularis into two groups: the complete and incomplete types. From the geographic distribution, the residents with the complete type appeared for the first time in 1992 in the Oshima district (western Hokkaido). The age distribution indicated that persons with the complete type increased, since 1990, in the age groups younger than 30 years old.