Transmission of Echinococcus multilocularis in a large city: effects red fox (Vulpes vulpes) feeding behaviour and range utilization on environment contamination

• Main Author: Robardet, Emmanuelle
• Other Authors: Laboratoire Chrono-environnement (UMR 6249) (LCE), Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté COMUE (UBFC)-Université Bourgogne Franche-Comté COMUE (UBFC), Université de Franche-Comté, Patrick Giraudoux([e-mail]), Laboratoire d'études et de recherches sur la rage et la pathologie des animaux sauvages (AFSSA)
• Format: Doctoral or Postdoctoral Thesis
• Language: French
• Published: HAL CCSD 2007
• Subjects: red fox; urbanised area; eco-ethology; epidemiology; Echinococcus multilocularis; renard roux; milieux urbanisés; éco-éthologie; épidémiologie; [SDV.EE]Life Sciences [q-bio]/Ecology; environment; Renard; Microtus arvalis
• Online Access: https://theses.hal.science/tel-00338134; https://theses.hal.science/tel-00338134/document; https://theses.hal.science/tel-00338134/file/theseER_09_11_07.pdf

Alveolar Echinococcosis is a lethal zoonosis transmitted to humans by the ingestion of eggs of the tænia Echinococcus multilocularis. The cycle of the parasite needs a carnivore as definitive host (mainly the red fox) and the common and water voles (Microtus arvalis and Arvicola terrestris) as intermediate hosts. Since 20 years, the more and more common observations of urban foxes gave rise to many questions about the possible increased risk of transmission to man due to the proximity of foxes. Recent studies showed the presence of E. multilocularis in urban foxes with variable prevalence. However, the conditions of the development of this parasite in the urbanized area are few documented. Work presented here proposes to improve comprehension of the cycle of E. multilocularis in such urbanized area. A monitoring of the red fox infection by collection of road kills or trapped animals highlighted a "rural to urban" decreasing gradient of infection. Along this gradient, different habitats were regularly sampled; this study showed the importance for the red fox of the availability of Microtus sp. in waste land landscape. The study of the adaptation of its diet by red fox to the variations of rodents densities showed that the Microtus sp. was highly consumed even when it was poorly represented in the field whereas in peri-urban area, A. terrestris,is consumed according to its availability. Taking in account the availability of rodents on the scale of the city, it was shown that the consumption of intermediate hosts is more important in rural area than in urban area and that the rural diet exhibits a predominance of Microtus sp. versus A. terrestris whereas these differences are lacking in urban area. The distribution of faeces of the red fox appeared correlated with the densities of Microtus sp and A. terrestris, underlining the possibilities of closing the parasitic cycle whatever the urbanization level. Lastly, the study of foxes movements using GPS collars has allowed to observe various types of behaviours which ...