Plasticity of predation behaviour as a putative driving force for parasite life‐cycle dynamics: the case of urban foxes andEchinococcus multilocularistapeworm

Abstract

Summary1. Parasite transmission frequently depends on an intermediate host species being subject to predation by a definitive host. We hypothesized that the population dynamics of this type of parasite would be affected by plasticity of the predation behaviour of the final host. The zoonotic tapeworm Echinococcus multilocularisLeuckart is transmitted to foxes ( Vulpes vulpes L.) by predation on infected rodents. One possible mechanism underlying the significant decrease in the prevalence of E. multilocularis in red foxes observed towards the centre of Zurich (Switzerland) is that the relative abundance of intermediate hosts varies between different urbanized habitats. 3. The water vole, Arvicola terrestris scherman L., which is the major intermediate host, was less abundant in urban compared with peri-urban areas, due to both a reduced availability of suitable habitats and lower numbers within those habitats. Stomach content analyses indicated that foxes in urban areas consumed more anthropogenic food but preyed less frequently on rodents -and those rodents taken belonged to species less susceptible to E. multilocularis infection. 4. We conclude that the functional response of final hosts to changes in supply of intermediate hosts and alternative food sources can significantly affect the transmission dynamic of dixenous parasites, such as this zoonotic tapeworm.

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

“…The same trend was observed in Switzerland: Zürich (Hegglin et al, 2007;Hofer et al, 2000) and Geneva (Fischer et al, 2005). The first report of an urban cycle for E. multilocularis concerned the city of Zürich.…”

“…The analysis of the effect of urbanisation level, year, season, age class and sex have shown that urbanisation only explained fox infection. Other studies have revealed a seasonal prevalence in an urban area with higher rate in winter for young males (Hofer et al, 2000) and more pronounced variation along the urbanisation gradient in juveniles foxes than in adult foxes (Hegglin et al, 2007). In our study urban positive cases were juveniles males.…”

“…The first report of an urban cycle for E. multilocularis concerned the city of Zürich. Diagnosis in red foxes in this city revealed a high preva- lence of E. multilocularis between 16.5 % in the urban area, 39.5 % in adjacent areas and 62.9 % in peri-urban area (Hegglin et al, 2007). In the present study, the gradient of infection reached 4 % in the urban area, 31 % in the peri-urban area and 54 % in the rural area.…”

“…However it occurs a considerable infection risk to human due to the high fox population in cities (Romig et al, 2006a). Definitive host contamination is due to eating rodents, and epidemiological studies have shown the impact of their availability on rural red fox infection (Delattre et al, 1988;Giraudoux et al, 2002;Raoul et al, 2003) and more recently in urban red fox infection (Hegglin et al, 2007). Diet analysis of urban red foxes has revealed changes in feeding habits, compared to the more traditional biotopes, with a larger consumption of anthropogenic food (Baker et al, 2000;Contesse et al, 2004;Doncaster et al, 1990).…”

Canine echinococcosis in Kyrgyzstan: Using prevalence data adjusted for measurement error to develop transmission dynamics models

“…The infection pressures reported for E. multilocularis assume that infection pressure is constant throughout the year which is unlikely. In Switzerland for example, differences in prevalences have been suggested between foxes sampled in the winter and the summer (Hofer et al, 2000;Stieger et al, 2002;Hegglin et al, 2007). Studies are being undertaken to resolve the issues of seasonal transmission in Kyrgyzstan.…”