Preliminary study of the role of red foxes in Echinococcus multilocularis transmission in the urban area of Sapporo, Japan

Abstract

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.

Trophic ecology, behaviour and host population dynamics in Echinococcus multilocularis transmission

“…The urban cycle of the parasite is now documented in Zurich and Geneva (Switzerland), Stuttgart (Germany), Copenhagen (Denmark), Sapporo (Japan), Nancy, Annemasse and Pontarlier (France), and Calgary (Canada) (Hofer et al, 2000;Tsukada et al, 2000;Deplazes et al, 2004;Fischer et al, 2005;Robardet et al, 2008;Catalano et al, 2012;Comte et al, 2013). A general pattern that seems to emerge is a decrease in E. multilocularis prevalence in foxes according to the following gradient: rural periphery/residential peri-urban area/urban centre.…”

“…Tsukada et al (2000) analysed the distribution of foxes by detecting fox footprints in winter in 130 parks and woodlands evenly distributed within the city and sampled fox faeces in approximately 19 fox dens in the area. Significantly more footprint-positive parks and woodlands were located in the peripheral area (47.6%) than in the urban centre (22.9%), and copro-ELISA positive faeces were collected in 11 out of 19 dens, with only one located in the urban centre.…”

Infection of foxes byEchinococcocus multilocularisin urban and suburban areas of Nancy, France: influence of feeding habits and environment

“…In Europe, the red fox is the main source of environmental contamination (Deplazes & Eckert, 2001). Recent studies have shown the presence of E. multilocularis in red fox in various cities: Copenhagen (Kapel & Saeed, 2000), Geneva (Fischer et al, 2005), Prague (Martinek et al, 2000), Stuttgart (Romig et al, 1999), Zürich (Hofer et al, 2000) in Europe, Sapporo (Tsukada et al, 2000) and Otaru (Yimam et al, 2002) in Japan. The prevalence among urban foxes was lower than among suburban or rural foxes.…”

Dispersal of male bears into peripheral habitats inferred from mtDNA haplotypes

“…They may also infect humans with rabies or alveolar echinococcosis by the tapeworm Echinococcus multilocularis (Uraguchi et al 2009). The first case of alveolar echinococcosis infection in a Sapporo resident was reported in 1997 (Tsukada et al 2000). The public health issues such as preventing risk of zoonosis associated with the presence of wildlife in cities are the focus of much research, as is the drive for extensive control measures (Bateman and Fleming 2012).…”