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With the ongoing spread of Echinococcus multilocularis in Europe, sanitary authorities are looking for the most efficient ways of reducing the risk for human populations. Fox culling is one particular tool that has recently shifted from predation control to population health management. Our study aims to assess the effectiveness of this tool in limiting E. multilocularis prevalence in fox populations in France. During four years, a culling protocol by night shooting from cars was implemented around the city of Nancy (eastern France) representing ∼1700h of night work and ∼15,000km driven. The 776 foxes killed represented an overall increase of 35% of the pressure on the fox population over 693km 2 . Despite this consequent effort of culling, not only did night shooting of foxes fail to decrease the fox population, but it resulted in an increase in E. multilocularis prevalence from 40% to 55% while remaining stable in an adjacent control area (585km 2 ). Though no significant change in age structure could be described, an increase in immigration and local recruitment is the best hypothesis for population resilience. The increase in prevalence is therefore considered to be linked to a higher rate of juvenile movement within the culled area shedding highly contaminated faeces. We therefore advocate managers to consider alternative methods such as anthelmintic baiting, which has been proven to be efficient elsewhere, to fight against alveolar echinococcosis., (Copyright © 2017 Elsevier B.V. All rights reserved.)

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.

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 33 km(2), with a density of 40 baits/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., (Copyright © 2013 Elsevier B.V. All rights reserved.)