In order to assess the infection risk of alveolar echinococcosis among urban residents of Sapporo, the capital of Hokkaido,
Japan, a survey was conducted on fox distribution in the urban area and on the prevalence of Echinococcus multilocularis
among the foxes. The fox distribution, evaluated from fox footprints left on the snow in parks and woodlands, and from
locations of fox carcasses recorded by the Sapporo municipality, was concentrated along the border of the urban area and
in the southwestern part of the city, facing the mountain. Fox faeces were collected around active fox dens, and analysed
by a coproantigen detection assay and parasite egg examination for the Echinococcus infection. Thirty-three out of 155
faeces were coproantigen positive. Coproantigen-positive faeces were collected from 11 den sites (57·9% of total den sites),
and all except 1 were located in the urban fringe. A high intensity of taeniid eggs (>100 eggs per 0·5 g) containing faeces
were also collected in the 3 sites of them. Although Echinococcus infection in rodents was not observed from the necropsy
of 23 rodents captured around active fox dens, arvicolid rodents, a suitable intermediate host for E. multilocularis, were
captured in the urban fringe. Therefore, the urban fringe offers suitable conditions in which the life-cycle of E.
multilocularis could be maintained. Prompt measures to control echinococcus infection should be taken, even in urban
areas.