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

Abstract

Summary :This study evaluated the impact of biological and environmental factors on the infection of red foxes (Vulpes vulpes) by Echinococcus multilocularis in an endemic area of north-east France. From January 2004 to April 2006, 127 foxes were examined for E. multilocularis and their stomach contents analysed. The effect of year, season, age, sex and urbanisation level on E. multilocularis presence was estimated using a General Linear Model (GLM) with logit link, (i.e. logistic regression). Urbanisation level was the only influencing factor, with a decreasing gradient from rural [54 %,] to peri-urban [31 %, CI 95 % (15-52)] and urban area [4 %,]. The consumption of Arvicola terrestris and Microtus sp., grassland species, the main presumed intermediate hosts of E. multilocularis, was studied by the same approach. The two species were consumed less in the urban area and more in autumn than in spring. Anthropogenic food consumption was linked to urbanisation and to age. The frequency of anthropogenic food consumption decreased in the rural area. A global model explaining the presence of E. multilocularis and including urbanisation level and diet was then elaborated. Independently of urbanisation, there was a suggestion of less E. multilocularis infection with anthropogenic food consumption. Red foxes consuming Microtus sp. and A. terrestris had higher worm burden than those that did not. The results suggest that the decreasing gradient observed from rural to urban area is linked to behaviour and feeding habits. Résumé : INFECTION DES RENARDS PAR ECHINOCOCCUS MULTILOCULARIS DANS LES ZONES URBAINES ET PÉRI-URBAINES

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

“…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. The distribution of intermediate host populations has been investigated in Zurich and Nancy (Hegglin et al, 2007;Robardet et al, 2008) with similar findings (see Table 2 for a comparison between Zurich and Nancy cities, where key ecological parameters of the cycles have been documented). Indeed, one of the main fox prey species displayed a higher density in the rural periphery (M. arvalis in Nancy) and/or in the residential peri-urban area (A. scherman in Zurich) compared to the urban centre where the relative densities of both prey species were lower due to reduced availability of suitable habitats (grasslands) and the lower numbers of animals within these habitats.…”

“…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.…”

“…The fox diet in an urban transmission context has been investigated in Zurich and Nancy (Hegglin et al, 2007;Robardet et al, 2008). The presence of arvicolid rodents (i.e.…”

“…The functional response reflects the variation of the predator's diet following the variation of the density of its prey (Arditi and Ginzburg, 2012). In the context of E. multilocularis transmission, a numerical response would theoretically lead to higher fox populations when prey density increases, thereby increasing Hegglin et al, 2007;Robardet et al, 2008Robardet et al, , 2011. Z: Zurich, N: Nancy.…”

Rodents as shared indicators for zoonotic parasites of carnivores in urban environments

“…Therefore, the environmental contamination by infectious free-living stages, and thereafter the infection pressure by these parasites, is likely to differ and depend on the distribution, abundance and habitat use of the respective definitive hosts, notably in urbanized areas. High prevalences of infection with T. canis in domestic dogs and red foxes in urban areas (O'Lorcain, 1994 ;Habluetzel et al 2003 ;Reperant et al 2007), and high prevalences of infection with E. multilocularis in red foxes in peri-urban areas (Hofer et al 2000 ;Fischer et al 2005 ;Robardet et al 2008) have notably been reported, suggesting high levels of environmental contamination in these environments.…”