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International audience; In zoonotic infections, the relationships between animals and humans lead to parasitic disease with severity that ranges from mild symptoms to life-threatening conditions. In cities and their surrounding areas, this statement is truer with the overcrowding of the protagonists of the parasites' life cycle. The present study aims to investigate the distribution of a parasite, Echinococcus multilocularis, which is the causative agent of alveolar echinococcosis, using copro-sampling in historically endemic rural settlements of the eastern part of France and in newly endemic areas including urban parks and settlements surrounding Paris. Based on 2741 morphologically identified and geolocalized copro-samples, the density of fox faeces was generally higher in the surrounding settlements, except for one rural area where the faeces were at larger density downtown in the winter. Fox faeces are rare but present in urban parks. Dog faeces are concentrated in the park entrances and in the centre of the settlements. DNA was extracted for 1530 samples that were collected and identified from fox, dog, cat, stone marten and badger carnivore hosts. Echinococcus multilocularis diagnosis and host faecal tests were performed using real-time PCR. We failed to detect the parasite in the surroundings of Paris, but the parasite was found in the foxes, dogs and cats in the rural settlements and their surroundings in the historically endemic area. A spatial structuring of the carnivore stool distribution was highlighted in the present study with high densities of carnivore stools among human occupied areas within some potentially high-risk locations.

International audience; In Europe, most cities are currently colonized by red foxes (Vulpes vulpes), which are considered to be the main definitive host of the zoonotic cestode Echinococcus multilocularis. The risk of transmission to humans is of particular concern where high fox populations overlap with high human populations. The distribution of baits containing praziquantel has successfully reduced the infection pressure in rural areas and in small plots within large cities. The purpose of this study was to assess its efficiency in two medium size cities (less than 100,000 inhabitants) in areas of high human alveolar echinococcosis incidence. From August 2006 to March 2009, 14 baiting campaigns of praziquantel treatment were run in Annemasse and Pontarlier (Eastern France), each of which encompassed 33km(2), with a density of 40baits/km(2). The bait consumption appeared to be lower in strictly urban context compared to suburban areas (78.9% vs. 93.4%) and lower in Annemasse than in Pontarlier (82.2% vs. 89.5%). During our study, the prevalence of E. multilocularis, as assessed by EM-ELISA on fox faeces collected in the field in Annemasse, was lower within the treated area than in the rural control area. A "before/during" treatment comparison revealed a significant decrease of spring prevalence from 13.3% to 2.2%. No significant change in prevalence was detected in Pontarlier (stable prevalence: 9.1%) where the contamination of the treated area followed the temporal trend observed in the control area. There, a greater resilience of the parasite's life cycle, probably due to a strong pressure of recontamination from outside the treated area, may have counteracted the prophylaxis treatment. These contrasted outcomes suggest that the frequency of fox anthelmintic treatment should be adapted to the local situation.

International audience; Alveolar echinococcosis is considered to be the most serious zoonosis in the Northern Hemisphere's cold or temperate regions. In Europe, the parasite has a sylvatic life cycle based on predator-prey interactions, mainly between red foxes and small rodents. Echinococcus multilocularis has been observed to have spread across Europe over the last three decades. In France, a westward spread of the parasite's known endemic areas has been described. In this study, a retrospective analysis of fox feces by real-time PCR was carried out in four départements not previously investigated and considered free along with two endemic control departments. The fox feces collected from 2000 to 2004 were analyzed by real-time PCR. Fecal prevalence in the two endemic departments of Doubs and Côte d'Or were estimated at 12 % [6.4-20.0 %] and 4.2 % [1.1-10.3 %], respectively. No positive samples were identified among the 72 feces collected in Drôme or the 112 from Allier, which is consistent with the very low expected prevalence should the parasite be present. Three positive samples were recovered in the Seine-Maritime and Hautes-Alpes départements, resulting in a prevalence of 3.5 % [0.7-10.0 %] and 2.5 % [0.5-7.1 %], respectively. From now on, Hautes-Alpes constitutes the new southern border of the endemic areas in France and confirms the southward expansion previously highlighted. Real-time copro-PCR proved useful in identifying new endemic areas even with low prevalence. Due to the spread of E. multilocularis in France and associated zoonotic risk, it is necessary to expand surveillance in order to fully define all the country's endemic areas. On a continental scale, the development and harmonization of surveillance programs are now needed in order to obtain a global overview of the presence of E. multilocularis and to tailor potential countermeasures.

Echinococcus multilocularis is the causative agent of alveolar echinococcosis, a severe zoonotic disease. It is maintained through a sylvatic life cycle based on predator–prey interactions mainly between foxes and rodents. Dogs are also good definitive hosts; and due to their close proximity to humans, they may represent a major risk factor for the occurrence of human cases. In two medium-sized cities of Eastern France (Annemasse and Pontarlier), located in highly endemic areas, 817 dog feces samples were collected and analyzed by a flotation technique followed by a multiplex PCR assay. For the first time in France, we assessed the presence of E. multilocularis DNA in four dog feces samples, in which it represents an estimated prevalence of 0.5 % (95% CI; 0.1 % 1.3 %). Eight other samples presented taeniid infections from three different species (Taenia crassiceps, Taenia serialis, and Taenia polyacantha). When considering both E. multilocularis and Taenia sensu lato, prevalence rose to 0.6 % in Annemasse and 2.6 % in Pontarlier. In this highly endemic context, proper application of the usual deworming recommendations (70 % of the dogs were treated twice a year or more) failed to prevent dog infection, particularly for hunting dogs. Our results stressed the need to adapt treatment to the environmental context and to the specific activity of dogs. Further epidemiological surveys in domestic dogs and cats using this coprological approach are still needed to obtain a better overview of infection and the associated zoonotic risk.

International audience; During 2005-2010, we investigated Echinococcus multilocularis within fox populations in a large area in France. The parasite is much more widely distributed than hitherto thought, spreading west, with a much higher prevalence than previously reported. The parasite also is present in the large conurbation of Paris.