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International audience; Trophic interactions, eg predation and herbivory, are one of the main biotic interactions driving the composition and functioning of terrestrial and aquatic food webs as they sustain energy and matter flows among organisms. The relationship between a resource availability and its consumption rate by a predator or herbivore, the functional response, is complex since often non-linear in shape and likely to depend upon the availability of other resources. Trophic interactions also nest the transmission of a large variety of multi-hosts parasites (ie trophically-transmitted parasites, TTP) within food webs. Moreover, the capacity to acquire, develop and transmit a parasite, called competence, vary among host species. The use of mathematical approaches, such as mechanistic dynamic models, to explore the transmission dynamics of TTP have often ignore the complexity of functional response and the variation in host competence. However, a prerequisite for understanding and modeling the ecology of TTP is to identify hosts species that are involved in transmission, ie the consumption of which ensures the parasite to step from the larval to the adult stage. This translates into the simple question “who is eating whom?”. Traditional techniques for investigating feces or stomach content based on macro- or microscopic identification of food remains fail to achieve fine taxonomic resolution identification of ingested items. Recently, DNA-based techniques such as metabarcoding have arisen as a powerful approach for the simultaneous taxonomic identification of several food items in feces or stomach content with high taxonomic resolution.We built a “one predator-two prey” eco-epidemiological model using a system of ordinary differential equations which allows for complex predation patterns. Using parameters related to Echinococcus multilocularis transmission in wildlife in Eastern France, we analyzed to what extent variations in prey diversity, total density and competence to transmit the parasite impact the basic reproductive number R0, which is a measure of disease outbreak risk. In parallel, we developed a molecular metabarcoding approach to investigate the diet of dog and red fox in rural settings of Eastern France, Gansu and Kyrgyzstan where E. multilocularis is endemic. Preliminary results, advantages and limitations, as well as perspectives of these recent developments will be presented.

International audience; From continental to regional scales, the zoonosis alveolar echinococcosis (AE) (caused by Echinococcus multilocularis) forms discrete patches of endemicity within which transmission hotspots of much larger prevalence may occur. Since the late 80s, a number of hotspots have been identified in Europe and continental Asia, mostly in China, wherein the ecology of intermediate host communities has been described. Here we present a comparative natural history and characteristics of transmission ecosystems, with a particular focus on the Alay Valley hotspot, recently studied.

International audience; From continental to regional scales, the zoonosis alveolar echinococcosis (AE) (caused by Echinococcus multilocularis) forms discrete patches of endemicity within which transmission hotspots of much larger prevalence may occur. Since the late 80s, a number of hotspots have been identified in Europe and continental Asia, mostly in China, wherein the ecology of intermediate host communities has been described. Here we present a comparative natural history and characteristics of transmission ecosystems. On this basis, regional types of transmission and their ecological characteristics have been proposed in a general framework. Combining climatic, land cover and intermediate host species distribution data, we identified and mapped spatially distinct types of transmission ecosystems typified by the presence of 'flagship' intermediate host species. Each transmission ecosystem had its own characteristics which can serve as a reference for further in depth research in the transmission ecology of E. multilocularis. This approach may be used at fine spatial scales to characterize other poorly known transmission systems of the large Eurasian endemic zone, and help in consideration of surveillance systems and interventions.

Many issues in fundamental and applied ecology require the use of sampling protocols at the sectoral or even regional scales at which many important ecological mechanisms occur. The lack of workable sampling methods at these scales is a major obstacle to the analysis and understanding of these mechanisms. We test the validity of an index method of estimating relative population densities, applicable along transects of several kilometers in length, for a population of Common Voles (Microtus arvalis). The results show that the index method of estimating relative density is well adapted for monitoring variations in the abundance and spatial distribution of Common Vole populations and authorizes studies for a wide range of objectives and spatial scales., De nombreuses questions d’écologie fondamentale ou appliquée imposent l’application de protocoles d’échantillonnage à des échelles sectorielles, voire régionales, auxquelles se réalisent de nombreux mécanismes écologiques importants. L’absence de méthodes d’échantillonnage utilisables à ces échelles représente un obstacle majeur à l’analyse et à la compréhension de ces mécanismes. Pour une population de Campagnols des champs (Microtus arvalis) nous avons testé la validité d’une méthode d’estimation indiciaire en densité relative applicable le long de transects plurikilométriques. Les résultats obtenus montrent que cette méthode d’estimation indiciaire en densité relative est bien adaptée au suivi des variations d’abondance et de distribution des populations du Campagnol des champs et autorise des études pour une grande diversité d’objectifs et d’échelles spatiales., Quéré Jean-Pierre,Raoul Francis,Giraudoux Patrick,Delattre Pierre. An index method of estimating relative population densities of the Common Vole (Microtus arvalis ) at landscape scale. In: Revue d'Écologie (La Terre et La Vie), tome 55, n°1, 2000. pp. 25-32.

International audience; Small mammal distribution was studied along a grazing gradient in a pastoral landscape of the Tibetan plateaus of Western Sichuan, China. Smaller small mammals (< 100 grams) were sampled using standard trapping. The link between habitat and both smaller and larger small mammal distribution on a landscape scale was estimated using landscape transects. The relative density of the Microtus oeconomus/limnophilus complex ranged from higher levels in fenced grassland and bushes (i.e. low grazing pressure), to lower levels in habitats with a high grazing pressure, where this species was not trapped. Ochotona curzoniae, O. cansus and Cricetulus kamensis displayed a reverse gradient, with higher relative densities in overgrazed habitats (bare grounds). The distribution of Microtus irene was restricted to two slope habitats: rocky slopes and Stellera chamaejasme grassland. Microtus leucurus was only trapped in Potentilla fruticosa bushes and in a single grassland type, having an intermediate stage of degradation. These results suggest a differential response of the small mammal species, in terms of relative density, to grazing pressure level.

International audience; Small mammals such as the European rabbits, the plateau pikas, the prairie dogs have been traditionally perceived as pests and targeted for control on a large scale despite their importance as key-stone species in their native ecosystem. This is also the case for the fossorial form of the water vole (Arvicola terrestris). This species can reach large population densities and causes heavy damage to grassland with subsequent economic losses for farmers (9,000 to 25,000 € for a 70 ha farm during an outbreak year in Franche-Comté, France). However, higher population densities of A. terrestris and also of Microtus arvalis, help maintaining a large and rich community of vole predators. Such non-target species (red kite, common buzzard, wild boar, red fox, etc.) are impacted, some of them heavily, by the unconditional use of rodenticides (e.g. bromadiolone). In order to minimize the use of rodenticides in controlling A. terrestris populations, a long term research program has been undertaken since the late 80s, aiming at identifying the key-parameters of such regional systems. Based on a systems approach, this collaborative research network involves academic researchers, farmer, game, conservationist organizations and governmental and local administrations together. On a regional scale (area of about 2500 km2), Delattre et al. (1992), Giraudoux et al. (1997), Fichet et al. (2000) provided evidence that M. arvalis and A. terrestris population dynamic patterns correlate with land composition. On a sectorial scale (area of about 25 km2), Delattre et al. (1996), Delattre et al. (1999) showed for M. arvalis that landscape heterogeneity dampen population fluctuations and may modulate prey/predator relationships; Duhamel et al. (2000) that A. terrestris outbreak epicentres occur in homogeneous grassland and Foltete et al. (2008) that hedgerow networks slow down the propagation of travelling waves. On a local scale (area of about 0.01 km2), Delattre et al. (2006), Morilhat et al. (2007, 2008) showed that A. terrestris population growth was enhanced by larger gallery networks of Talpa europea, was slowed down by ploughing and cattle tramping and was modified by neighbouring landscape (10 - 100 ha). This led to a number of recommendations, now implemented for a more sustainable control of A. terrestris (Delattre and Giraudoux 2009) with substantial decrease in rodenticide utilization and lesser impact on non-target species. Poster downloadable at: http://pagesperso-orange.fr/giraudoux/PosterSETAC_120416_1200.pdf

International audience

International audience; In a fascinating article, Delibes-Mateos et al. (2011) pint point that small mammals such as the European rabbits, the plateau pikas, the prairie dogs have been traditionally perceived as pests and targeted for control on a very large scale despite their importance as key-stone species in their native ecosystem. This is also the case for many species of voles in Eurasia and North America (see e.g. Giraudoux and Raoul 2010). However, although a considerable number of studies have been undertaken at local and other scales to understand the mechanisms of vole population outbreaks and cycles, few of them provide basic concepts and useful elements that can be used by ecosystem managers on the scales requested. Lidicker (1995) and Barret & Peles (1999) wrote the first books providing a landscape ecology perspective to small mammal studies. During the 90s, a number of studies have shown that small mammal population management could be grounded on knowledge on the effect of landscape on population dynamics. Here we present results obtained from the long term and multi-scale study of two grassland species, Microtus arvalis and Arvicola terrestris to illustrate this approach. We describe at which scales landscape variables were found relevant to explain population dynamics and the consequences of the observed population dynamic patterns on the vertebrate community (other small mammal species and predators including species of conservation value). We argue that long term observational studies at various scales are of primary importance to understand the role of small mammals in regional ecosystems and essential to put experimental studies into relevant context. Such knowledge is critical to provide managers with useful concepts for integrated sustainable landscape management, to protect biodiversity and also for pest and disease control.

International audience; Aim The Llanos de Ojuelos in Mexico's Central High Plateau supports unique Opuntia scrublands and the southernmost Chihuahuan grasslands. Although human activities have modified strongly its landscape and impacted its biodiversity at an unknown scale, such impacts are poorly known. We aimed at understanding how nocturnal rodent species distributed across the landscape and formed assemblages and on the role and integration of the different habitats at the landscape level. Location The study was carried out at 43 sites in a study area of approximately 3350 km 2 in the Llanos de Ojuelos. Methods During the Spring of 2008, we surveyed nocturnal rodents, through live-trapping. We redefined habitat classes based on log-linear multinomial regressions of rodent captures. Species rarefaction curves and true alpha, beta and gamma diversities were calculated for the different habitat classes. A map of the different habitats was constructed based on Landsat imagery. Results We captured 458 individuals of 20 rodent species. Multinomial regressions caused the merger of 11 a priori defined habitat classes into 7. Leguminous scrub and mixed nopaleras, both secondary habitats, had the highest alpha and gamma diversity values. Closed arboreal nopaleras and grasslands had the highest within-habitat variability ((1)D(beta)) and the lowest area coverage. Within-habitat (1)D(beta) was larger than landscape (1)D(beta), because of the great overlap in rodent assemblage composition between the habitats. Main conclusions There are no 'typical' rodent assemblages per habitat class, but they are organized loosely and have fuzzy borders. Rodent community organization was highly species-centred. At the landscape level, secondary habitats have a profound effect on rodent diversity and should be included in management schemes for biological conservation. The most endangered habitats seem to be the closed arboreal nopaleras and grasslands. Any conservation efforts must consider their conservation and an increase in the size of remaining patches.

"Will there ever be a field of landscape ecotoxicology?". Ainsi John Cairns Jr questionnait-il la communauté des écotoxicologues en 1993, évoquant sa fascination pour les récents développements de l'écologie du paysage (Cairns Jr 1993). L'écotoxicologie, une discipline née de la toxicologie dans les années 1960 qui étudie le devenir et les effets des polluants dans les écosystèmes, n'a eu de cesse, en marge des approches classiques nécessaires aux travaux appliqués exigés par la société (évaluation du risque par exemple), d'adopter les concepts et les outils de l'écologie. Cependant, si les écotoxicologues se sont effectivement approprié un certain nombre d'outils utilisés également par l'écologie du paysage (télédétection, géostatistiques, etc.), peu d'entre eux ont réellement adopté ses concepts et posé les hypothèses selon lesquelles le paysage pouvait moduler le transfert et les effets des polluants. Ces hypothèses, pourtant, ne manquent pas. Pourquoi le paysage (agricole, urbain, forestier, etc.), autant que le type de sol ou les propriétés pédologiques, variables très considérées en écotoxicologie, n'influencerait-il pas l'interception, la rétention ou la rémanence des polluants ? Pourquoi le paysage, par son influence sur les patrons de biodiversité, donc la complexité verticale (diversité dans chaque niveau trophique) et horizontale (nombre de niveaux trophiques, longueur des chaînes alimentaires, etc.) des réseaux trophiques, n'influencerait-il pas le transfert des polluants dans les écosystèmes, alors que son rôle dans la transmission des pathogènes commence à être clairement établi ? Pourquoi le paysage, en fonction de la manière dont il est exploité spatialement et temporellement par les organismes, n'influencerait-il pas le transfert (intensité du transfert, etc.) et les effets (effet aggravant ou atténuant de l'abondance des ressources alimentaires, etc.) des polluants ? Le mariage de l'écologie du paysage et de l'écologie des transferts de toxiques, aurait l'avantage, dans une approche systémique partagée, de prendre en compte l'espace et le temps, la variété des échelles signifiantes et l'impact de l'homme sur son environnement. La présente communication a pour but, en s'appuyant sur quelques exemples, d'explorer ce que pourrait-être ce champ de recherche.

Comprendre les mécanismes d'émergence régionale et mondiale d'organismes pathogènes dans le cadre des changements globaux constitue un des défis scientifiques posés à l'écologie. Selon les estimations, de 60 % à 80 % des organismes pathogènes pour les humains ont une origine animale ou un lien indirect avec la faune. L'écologie de la transmission des maladies infectieuses conduit le plus souvent à étudier des processus impliquant des interactions entre plusieurs espèces, voire entre plusieurs communautés. La distribution spatiale et les dynamiques temporelles des maladies infectieuses sont en effet dépendantes de la biodiversité, de la dynamique des populations d'hôtes, de l'herbivorie, de la prédation, de la dispersion individuelle et de l'hétérogénéité des conditions physiques et chimiques, toutes variables contrôlées à des degrés divers par le paysage. Pavlovski (1964) a forgé le terme "épidémiologie paysagère", Rioux et al. (1990), celui d'éco-épidémiologie pour désigner une approche systémique intégrant des méthodes héritées de l'écologie et de l'épidémiologie. Elle pointe l'importance de la définition de risques spatiaux, temporels, et populationnels. Cependant, les concepts de l'écologie du paysage y sont peu ou pas intégrés, de même que l'importance de l'observation multi-échelle des dynamiques de population d'hôtes et des interactions entre paysage et ces dynamiques (Giraudoux et al. 2008). Patz et al. (2004) dans un article intitulé "Unhealthy landscapes: policy recommendations on land use change and infectious disease emergence" recommandent la création et le soutien de centres de recherche et d'enseignement d'excellence en écologie et santé, afin, entre autres, de faciliter la conduite de recherches interdisciplinaires et la formation de professionnels capables d'accompagner non seulement ce type de recherche mais aussi la diffusion des résultats acquis en direction du grand public et des décideurs. Les concepts élaborés dans le domaine de l'écologie du paysage sont particulièrement adaptés à ce type d'intégration pluridisciplinaire où doivent se rencontrer spécialistes de la biodiversité, de la dynamique des populations, des sciences de la santé (humaine, animale et végétale) et des sciences humaines. Cette communication a pour but de présenter le cadre général de cette approche et de l'illustrer par quelques exemples.

International audience; Functional response of predators to prey density variations has been already documented to understand predation patterns. However, the consequences of functional response on parasite transmission remain largely unexplored. The rodents Microtus arvalis and Arvicola terrestris are the main preys of the red fox Vulpes vulpes in eastern France. These species are intermediate and definitive hosts of the cestode Echinococcus multilocularis. We explored fox dietary and contamination responses to prey density variations. The dietary response differed between the two prey species: no response for M. arvalis and a type-III like (sigmoidal) response for A. terrestris with a possible interference with M. arvalis. Fox contamination response followed a type-II shape (asymptotic) for both species. We conclude that fox predation is species-specific and E. multilocularis transmission is likely to be regulated by a complex combination of predation and immunological factors. These results should provide clues to better understand biological and ecological mechanisms involved in the transmission dynamics of trophically transmitted parasites when multiple hosts are involved. Also the relevance of models of parasite transmission should be enhanced if non-linear patterns are taken into account.

International audience; Building predictive maps of assemblage habitat, a widely used method in conservation and landscape management, is based on fitting habitat model on a training area, corresponding to a limited region in the environmental space. Model predictive performances need to be robustly evaluated on test data set. This is often realized at the landscape level, i.e taking as test data set one part of the original sample or a resampling one. Predicting assemblage occurrences at a regional level requires a step further in the modelling validation stage: testing model extrapolation performances. We estimated and compared the predictive performances of two scales of predictive mapping of small mammals assemblages in a remote area of Sichuan province. Small mammal assemblages were defined in two distant areas and differed between both areas. Their habitats were modelled, predicted and mapped using ETM bands at two different spatial scales: local (in each area) versus regional (including both areas). While locally trained models provided large predictive errors on independent data sets, the regionally trained model more accurately predicted assemblage occurrences and could be considered at this state of the research as an appropriate method to map assemblage regionally.

International audience; The Llanos de Ojuelos is an extensive llanura at the southern end of the Chihuahuan Desert. The original composition of the land is mostly grasslands, with interspread shrublands, and small water bodies. Currently, 80% of the area is used for crop production and/or grazing of livestock. As a result, natural habitats have been severely fragmented, and the overall biodiversity affected to an unknown degree. The present work aims at understanding the relationship between rodent assemblages and different types of habitat patches to integrate a landscape approach of small mammal diversity. In the spring of 2008 we inventoried the rodents at 74 locations in the area, through the use of Sherman live-traps (40 traps during two nights, per site; total=5920 night-traps). We covered the major perennial vegetation types. We captured 458 individuals of 20 species of rodents (Perognathus flavus, Chaetodipus hispidus, Chaetodipus nelsoni, C. pennicillatus, Dipodomys ordii, D. merriami, D. phillipsii, Liomys irroratus, Peromyscus boylii, P. difficilis, P. eremicus, P. gratus, P. maniculatus, P. melanophrys, Reithrodontomys fulvescens, R. megalotis, Baiomys taylori, Neotoma goldmani, N. leucodoni, and Onychomys arenarius). We defined a priori 11 rodent habitat categories based on the cover, structure and dominant plant species. Species presence/absences were modeled jointly through a multinomial model, and then used to pool habitats by merging all habitat classes pair-wise and selecting the most parsimonious model by the Akaike Information Criterion for each iteration. This produced 7 habitat classes: Closed arboreal nopalera, mixed nopalera, grassland, leguminous scrubland, Dodonaea scrubland, cultivated nopalera, and oak scrub. Rodent communities analyzed have low levels of organization, with most species thriving in a variety of conditions, although some of them exhibited a certain habitat preference. Communities were distributed according to a gradient from "low open vegetation" to "dense tall vegetation," with fuzzy borders between them. The highest rodent richness was in nopaleras; mid richness, in leguminous scrub communities, and lower richness, in grasslands. This might have resulted from differences in habitat structure and within-habitat heterogeneity. Habitat types seemed also to be structured differently. We are exploring models employing reflectance data to classify satellite images according to habitat classes and to analyze their spatial relationship. Given the patchiness and the low organization level of the communities, biological conservation cannot be carried out in homogeneous areas, but must consider the entire landscape

National audience

International audience; Understanding the transmission ecology of parasites involves the challenge of studying the complexity of life-cycles at multiple levels of biological organisation and at various space-time scales. We think that a single field of science alone cannot fully address this issue and that a way to understand such complexity is to connect various fields of science, to consider the whole transmission system, and to identify which are the variables reasonably accessible to measurement and the relevant scales at which they may provide information about transmission processes and indicate a higher risk of transmission/emergence. Based on ongoing studies carried out in Europe and in China, the aim of the present paper is to discuss this approach and to show how results obtained from mass-screening of human populations may be combined to those obtained from small mammal and landscape ecology studies and modelling to promote an understanding of Echinococcus multilocularis transmission and to determine how differences in the time-space scales at which human infection and small mammal population dynamic processes occur may complicate the analysi

This study aims at estimating the effect of landscape composition on the availability of small mammal preys (in terms of biomass) to predators on a sectorial scale (n x 1 km2). Four study sites, representative of different stages of agriculture intensification, were selected in eastern France according to landscape composition. The population dynamics of Microtus arvalis, Arvicola terrestris, Clethrionomys glareolus and Apodemus sp. were monitored from 1992 to 1996 by using index methods and trapping. M. arvalis and A. terrestris population biomasses were stable in landscapes with low percentage of permanent grassland. M. arvalis populations displayed greater biomass variations with sharp declines in the sites where the proportion of permanent grassland to farmland was greater than 50 %. A. terrestris populations were very unstable in one study site where the proportion of permanent grassland to farmland was greater than 85 %. Synchronic patterns between M. arvalis populations and the populations of hedgerow rodents were suspected at sites with large fluctuations of M. arvalis : every decline of the populations of hedgerow rodents was concomitant with the M. arvalis decline. These results suggest that two kinds of ecological systems in terms of prey-resource variations for mammalian predators can be distinguished : (i) stable in landscapes with lower proportion of permanent grassland, and (ii) unstable, with grassland species crashes and synchronous declines of the rodent community, in landscapes with higher proportion of permanent grassland. Moreover, the population dynamics of small mammals were asynchronous between the four sites situated at relatively short distance (some tens kilometres)., L’objectif de cette étude est d’estimer l’effet de la composition du paysage sur les variations de disponibilité en biomasse de micro-mammifères pour les prédateurs, à l’échelle sectorielle (n x 1 km2). Quatre sites d’étude représentatifs d’un gradient d’intensification agricole ont été choisis dans l’est de la France en fonction de la composition du paysage. Les fluctuations de biomasses de Microtus arvalis et Arvicola terrestris (espèces prairiales), de Clethrionomys glareolus et Apodemus sp. (espèces de milieux fermés) ont été suivies de 1992 à 1996 par méthodes indiciaires et piégeage. Les synchronies entre les populations de M. arvalis et celles de rongeurs de milieux fermés ont été recherchées. Les fluctuations de biomasse de M. arvalis et A. terrestris sont stables dans les sites où la proportion de prairie permanente est la plus faible. Les populations de M. arvalis présentent les plus larges amplitudes de variation de biomasse et les déclins les plus prononcés dans les sites où la proportion de prairie permanente sur la surface agricole est supérieure à 50 %. Les populations d’A. terrestris ne sont instables que dans un site, là où la proportion de prairie permanente sur surface agricole est supérieure à 85 %. Les déclins de populations de rongeurs de milieux fermés (Clethrionomys glareolus et Apodemus sp.) sont concomitants de ceux de M. arvalis dans les sites à fortes variations de biomasse de cette dernière espèce. Ces résultats suggèrent deux types de fonctionnement, en terme de variation de disponibilité en proies pour les prédateurs : (i) stable dans les paysages à faible proportion de prairie permanente, et (ii) instable, avec des déclins prononcés et rapides des populations d’espèces prairiales, entraînant des déclins synchrones du peuplement de micro-mammifères étudié, dans les paysages à forte proportion de prairie permanente. Aucune synchronie dans les dynamiques de population de ces micro-mammifères n’est observée entre les sites d’étude, éloignés de quelques dizaines de kilomètres seulement., Raoul Francis,Defaut Régis,Michelat Dominique,Montadert Marc,Pépin D.,Quéré Jean-Pierre,Tissot B.,Delattre Pierre,Giraudoux Patrick. Landscape effects on the population dynamics of small mammal communities : a preliminary analysis of prey-resource variations. In: Revue d'Écologie (La Terre et La Vie), tome 56, n°4, 2001. pp. 339-352.

International audience; The Xinjiang Uygur autonomous region (XUAR) in north-western China is known to be endemic for Echinococcosis multilocularis, the causative agent of human alveolar echinococcosis (HAE). Despite regular reports of HAE cases in their region, very little is known about the local epidemiology of the disease or the transmission of E. multilocularis. The epidemiology of HAE in Xinjiang has now been investigated by the analysis of data collected from the medical records of 157 clinical cases who had attended the four main hospitals in the region. These data indicate that the disease is relatively common in the Altai, western Junggar, and Tianshan mountain ranges, whereas the Tarim and Junggar basins are likely to be of low endemicity. The prevalence of the disease in the Kunlun mountains is not clear. Semi-nomadic groups, especially those of Kazakh or Mongol origin, have a higher risk of infection than other ethnic groups. Prevalence of the disease in humans appears to be correlated with aspects of the local climate, such as annual precipitation and temperature. Red foxes, Microtinae, Ochotona spp. and Marmota spp. may be important hosts of E. multilocularis in the XUAR, sustaining the transmission cycles of the parasite.

International audience; The aim of this review is to discuss the situation of alveolar echinococcosis in France, in the light of the current knowledge on its transmission patterns in the world, especially Europe. An important risk of higher contamination of the rural environment may be suspected from newly reported cases of infected foxes or voles in several countries where the disease was not found before. Furthermore, the increase of prevalence rate in foxes in Bade-Würtemberg (Germany) and Franche-Comté (France), traditionally endemic, is also in support of this new trend. Urban foxes and the spreading of infected foxes to cities may also be the cause of the extension to urban and suburban areas of a disease which was believed to be limited to rural areas. The setting up of an epidemiosurveillance system for fox (dog, cat) populations is currently in progress. It will be grounded on coprotests (ELISA, PCR) for the detection of E. multilocularis material in definitive hosts faeces and on sampling based on the multiscale analysis of the characteristics of landscapes favourable to transmission. A register of human cases has been established at the European level (WHO collaborative centre of the University of Franche-Comté and University of Ulm and Hohenheim). Unfortunately, the evolution of the parasite distribution and of the risks of exposure in France is unrecognised. Progress in surveillance and prevention could be expected if health authorities would attribute higher priority to this disease.

International audience; The multiplicity of circumstances by which a host can capture a microbiological agent can be broken down into two simplified processes: 1. encounter between host and microbe, 2. compatibility of two organisms. Given that rodents include species of generally small size, inhabiting continental areas in closer proximity to man than many other mammals, they offer numerous chain of contamination. Microbiological surveillance must both consider the emergence of old and new microbial types and identify ecological and demographic condition placing man at risk. Since it is materially impossible to survey all existing pathogens, priorities must be set according to empirical, epidemiological and ecological considerations. One of the major challenges is how to make microbiological surveillance more effective by way of new tools for detecting demographic changes in rodent populations.