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Blood circulates through the vascular system to carry oxygen, nutrients and metabolites to and away from tissues, and as such is a key-component of animal physiology. The impacts of metal pollution on blood, however, are poorly documented in free-ranging vertebrates. While the counteracting effect of selenium on mercury toxicity is well known in marine mammals, its potential role against the toxicity of other metals is less studied, especially on terrestrial wildlife. We explored the consequences of chronic exposure to two non-essential metals (cadmium and lead) along a pollution gradient in Northern France, on eleven haematological parameters in two free ranging small mammals, the wood mouse Apodemus sylvaticus and the bank vole Myodes glareolus. We hypothesized that haematology was related to metal concentrations in tissues, and that selenium might exert modulating effects. Concentrations of cadmium and lead in the tissues indicated an increased chronic exposure to and accumulation of metals along the gradient. Some haematological parameters were not explained by any measured variables while some others varied only with gender or age. Red blood cells, red blood cells distribution width, and blood iron concentration, however, decreased with increasing cadmium in the tissues in wood mice. Red blood cells and haemoglobin decreased with increasing renal lead and hepatic cadmium, respectively, in bank voles. Red blood cells distribution width in wood mice increased with cadmium concentrations in the liver but this was counteracted by high selenium levels in the same organ. An interaction of selenium and lead on red blood cells was also observed in bank voles. Further, selenium concentrations were associated with an increase of monocytes in wood mice. The present results show that toxic metals were related to haematology changes, particularly erythrocyte indicators, and that some essential elements like selenium should be measured as well since they may counteract toxic effects.

International audience; In wildlife ecotoxicology, the rationale for using blood rather than other body fluids or tissues is that sampling blood is a minimally invasive technique without animal mortality, providing both ethical and scientific benefits. To date, few studies are available on the relationships between blood and organ metal concentrations of small mammals living in contaminated sites. The present work aimed to study the relationships between the concentrations of 18 essential and nonessential metals in blood and their concentrations in the liver and kidneys, two accumulation and target organs, in wood mice from a former lead and zinc smelter, Metaleurop Nord, in northern France. The results from Se, Pb and Tl indicate that blood levels may be used to predict concentrations in organs of small mammals. Conversely, for Cd, Cu, Fe, Mo, Ti and Zn, blood concentrations were poorly or not related to liver and kidney concentrations. In addition to accurately predicting the concentrations of some metals in target organs, blood can provide important information about the physiological and biochemical status of organisms, but further toxicokinetic research is required to develop the use of blood sampling as a minimally invasive biomonitoring and ecotoxicological method in wildlife.

Pollution with trace metals (TM) has been shown to affect diversity and/or composition of plant and animal communities. While ecotoxicological studies have estimated the impact of TM contamination on plant and animal communities separately, ecological studies have widely demonstrated that vegetation is an important factor shaping invertebrate communities. It is supposed that changes in invertebrate communities under TM contamination would be explained by both direct impact of TM on invertebrate organisms and indirect effects due to changes in plant communities. However, no study has clearly investigated which would more importantly shape invertebrate communities under TM contamination. Here, we hypothesized that invertebrate communities under TM contamination would be affected more importantly by plant communities which constitute their habitat and/or food than by direct impact of TM. Our analysis showed that diversity and community identity of flying invertebrates were explained only by plant diversity which was not affected by TM contamination. Diversity of ground-dwelling (GD) invertebrates in spring was explained more importantly by plant diversity (27% of variation) than by soil characteristics including TM concentrations (8%), whereas their community identity was evenly explained by plant diversity and soil characteristics (2-7%). In autumn, diversity of GD invertebrates was only explained by plant diversity (12%), and their identity was only explained by soil characteristics (8%). We conclude that vegetation shapes invertebrate communities more importantly than direct effects of TM on invertebrates. Vegetation should be taken into account when addressing the impacts of environmental contamination on animal communities.

International audience; Assessing the genetic diversity of the parasite Echinococcus multilocularis provides key information about the temporal and spatial strain flow in a given area. Previous studies indicated that a historical endemic area conventionally presents a relatively high genetic diversity, whereas peripheral or newly endemic areas exhibit a more restricted variability of the parasite. The Swiss plateau region is part of the European historically endemic area, and the genetic diversity has already been investigated by assessing either human metacestode isolates or adult worms from foxes. To date, there have been no studies covering the whole geographical area affected by the parasite. The aim of the present study was to make use of the domestic pig to investigate the genetic diversity of E. multilocularis in relation to spatial distribution. A total of 55 E. multilocularis-induced hepatic lesions from slaughtered pigs from Switzerland were studied using EmsB microsatellite analyzes, and findings were compared to already published data (originating from human, primate, foxes, and rodent samples). A total of 12 EmsB profiles were described among the domestic pigs, some of them presenting a clear spatial organization in the Swiss plateau, with three of the main profiles geographically separated. One of the 12 EmsB profiles has been newly identified for Switzerland in this study, while the other 11 profiles had been previously described in other Swiss E. multilocularis isolates from other hosts. Overall, a total of 18 EmsB profiles have so far been described within the Swiss endemic area. Six profiles appeared only among human, primate, rodent, and fox samples. Based on a richness and diversity accumulation analysis, the sampling efficiency for the whole studied area has now been improved considerably by compilation of 178 E. multilocularis specimens obtained from four different intermediate and one definitive host species in Switzerland.

International audience; Pollution with trace metals (TM) has been shown to affect diversity and/or composition of plant and animal communities. While ecotoxicological studies have estimated the impact of TM contamination on plant and animal communities separately, ecological studies have widely demonstrated that vegetation is an important factor shaping invertebrate communities. It is supposed that changes in invertebrate communities under TM contamination would be explained by both direct impact of TM on invertebrate organisms and indirect effects due to changes in plant communities. However, no study has clearly investigated which would more importantly shape invertebrate communities under TM contamination. Here, we hypothesized that invertebrate communities under TM contamination would be affected more importantly by plant communities which constitute their habitat and/or food than by direct impact of TM. Our analysis showed that diversity and community identity of flying invertebrates were explained only by plant diversity which was not affected by TM contamination. Diversity of ground-dwelling (GD) invertebrates in spring was explained more importantly by plant diversity (27% of variation) than by soil characteristics including TM concentrations (8%), whereas their community identity was evenly explained by plant diversity and soil characteristics (2–7%). In autumn, diversity of GD invertebrates was only explained by plant diversity (12%), and their identity was only explained by soil characteristics (8%). We conclude that vegetation shapes invertebrate communities more importantly than direct effects of TM on invertebrates. Vegetation should be taken into account when addressing the impacts of environmental contamination on animal communities.

International audience; The eggs of Echinococcus multilocularis, the infectious stage, are spread into the environment through wild and domestic carnivore faeces. The spatial location of the faeces containing infective E. multilocularis eggs is a key parameter for studying areas of exposure and understanding the transmission processes to the intermediate hosts and humans. Echinococcus multilocularis faecal prevalence is often assessed by detecting E. multilocularis DNA, not necessarily eggs. This work aimed to determine the percentage of faeces containing E. multilocularis eggs in a rural town and its surroundings and whether this level of precision is relevant in assessing exposure to E. multilocularis. For this purpose, we developed a combined molecular and microscopic approach to investigate the E. multilocularis exposure of potential hosts in the environment from field-collected carnivore faeces. Carnivore defecation patterns were then spatialized to study the spatial distribution of E. multilocularis. Faeces were screened for E. multilocularis DNA using a specific real-time quantitative PCR (qPCR). Echinococcus multilocularis eggs were morphologically identified from E. multilocularis-specific qPCR-positive faeces after sucrose flotation and individually confirmed through specific PCR and sequencing. The spatial distribution of E. multilocularis was studied using Kulldorff statistics. Echinococcus multilocularis eggs were identified mostly in fox faeces positive for E. multilocularis DNA by qPCR (n = 27/70) and only from 1 of 15 copro-samples from dogs and 1 of 5 from cats. The faecal prevalence of E. multilocularis DNA and eggs was overdispersed, with the same geographical patterns. These data suggest that E. multilocularis DNA and/or egg detection in carnivore faeces, mainly that of foxes, is appropriate in ecological studies of E. multilocularis transmission.

Background Bacterial meningitis remains a major threat for the population of the meningitis belt. Between 2004 and 2009, in the countries of this belt, more than 200,000 people were infected with a 10% mortality rate. However, for almost 20 years, important meningitis epidemics are also reported outside this belt. Research is still very poorly developed in this part of the word like in the Democratic Republic of Congo (DRC), which experiences recurrent epidemics. This article describes for the first time the spatio-temporal patterns of meningitis cases and epidemics in DRC, in order to provide new insights for surveillance and control measures. Methods Based on weekly suspected cases of meningitis (2000–2012), we used time-series analyses to explore the spatio-temporal dynamics of the disease. We also used both geographic information systems and geostatistics to identify spatial clusters of cases. Both using conventional statistics and the Cleveland’s algorithm for decomposition into general trend, seasonal and residuals, we searched for the existence of seasonality. Results We observed a low rate of biological confirmation of cases (11%) using soluble antigens search, culture and PCR. The main strains found are Streptococcus pneumoniae, Haemophilus influenzae and Neisseria meningitidis (A and C) serogroups. We identified 8 distinct spatial clusters, located in the northeastern and southeastern part of DRC, and in the capital city province, Kinshasa. A low seasonal trend was observed with higher incidence and attack rate of meningitis during the dry season, with a high heterogeneity in seasonal patterns occurring across the different districts and regions of DRC. Conclusion Despite challenges related to completeness of data reporting, meningitis dynamics shows weak seasonality in DRC. This tends to suggest that climatic, environmental factors might be less preponderant in shaping seasonal patterns in central Africa. The characterization of 8 distinct clusters of meningitis could be used for a better sentinel meningitis surveillance and optimization of vaccine strategy in DRC. Improving biological monitoring of suspected cases should be a priority for future eco-epidemiological studies to better understand the emergence and spread of meningitis pathogens, and the potential ecological, environmental drivers of this disease.

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; The new recent genus and species of three-toed jerboas (Rodentia: Dipodinae), from southern Ningxia, China, is described. This form demonstrated a unique mixture of external, cranial, and dental characters that individually are typical for one or another of all known genera of Dipodinae. Based on morphological characters, it is recovered as the part of Dipodinae tree, distinct from all other members due to its unique combination of morphological characters, and appears to be a nearly ideal living ancestor of all other dipodines. In contrast to morphology, the molecular data indicate a relatively young age for this lineage and consistently place it as the sister group to Stylodipus. The results of the molecular clock analysis suggest that the separation of the two lineages dates back to the Early Pliocene or the Pliocene/Miocene boundary. The estimated geographic range of the new form seems extremely small. The conservational status of the new species remains to be determined; however, the available information suggests that it requires protection.

International audience; Exposure of terrestrial mammals to chemical contaminants like trace metals (TMs) is considered to be mainly based on trophic transfer. Although relationships between TM transfer to animals and identity of contaminated food have been studied, the variation of the TM transfer with respect to diet diversity has been poorly documented. In this study, the oral exposure to TMs of wood mice Apodemus sylvaticus was investigated with respect to both the number of different items, i.e., diet richness, and the identity of items determined by metabarcoding from their stomach content, i.e., diet composition. The results showed that consuming Salicaceae, a known cadmium accumulator plant family, significantly increased exposure to cadmium and zinc. However, an increase in diet richness minimized exposure to cadmium when mice consumed Salicaceae items. This strongly suggests that TM accumulator items can lead to a high oral exposure to TMs but that such high exposure due to TM accumulator items can be "diluted" by diet richness due to other low accumulator items. Our results clearly indicate that both the presence of certain items in the diet and diet richness are important determinants of exposure to TMs in generalist animals, which matches the predictions of the "diet dilution hypothesis".

International audience; Mammals are mainly exposed to trace metals (TMs) via consuming contaminated food. Several studies have demonstrated relationships between metal concentrations in food and in animal tissues. However, potential effects of TMs on feeding behaviour of wildlife have been poorly documented under field conditions, despite experimental evidence showing that food selection is impacted by resource contamination. Here, we test the hypothesis that the diet of a generalist rodent, the wood mouse (Apodemus sylvaticus), is altered by soil TM contamination in the field. Wood mice were sampled in spring and in autumn along a gradient of soil contamination in the surroundings of a former smelter located in northern France. Available resources in the field were inventoried, and the diet of the animals was analysed using DNA metabarcoding. We demonstrated that (a) relationship between the resource richness in the diet and their richness in the field was altered by soil metal contamination. Wood mice specialized their dietalong the gradient of soil metal contamination for both plant and invertebrate resources in spring. We also showed that (b) preference for Salicaceae, a plant family accumulating metals, decreased when soil contamination increased. These results suggest that environmental TM pollution could act as a force modulating trophic interactions in terrestrial food webs, thereby affecting wildlife exposure to contaminants by trophic route.

Within the current context of global change, ecosystems face simultaneously multiple stressors such as environmental pollution, excessive enrichment, and additional disturbances affecting population dynamics. Numerous theoretical and empirical studies explored the transfer of contaminants by food ingestion between trophic levels, and how contaminant effects on survival and fecundity may change regime shifts of classical predator–prey dynamics. However, the extent to which those contaminants may influence the cascade effect of external stressors, as a change in resources (bottom-up cascade) or a variation in predator abundance (top-down cascade) is still poorly understood. We develop a data-driven model to explore how soil contamination modulates the food chain stability and resilience to changes in prey nutrient and in the apex predator mortality rate. We particularly focus on the ecotoxicological impact of the trace metal, cadmium, on a widespread raptor, the barn owl (Tyto alba), feeding on several prey distinct by their trophic positions: herbivores (Microtus spp.), omnivores (wood mouse Apodemus sylvaticus and bank vole Myodes glareolus) and insectivores (shrews: Crocidura spp. and Sorex spp.). Our model reveals the alternative steady states in population dynamics and the occurrence and position of regime shifts where a subtle change in conditions causes a sudden shift in the ecological system. Based on mathematical modelling and bifurcation analysis, the results show for instance that under toxicity threshold, where no population decline is observed, the contaminant weakens food-chain resilience. Then at higher contamination, the toxic effects on predator releases the top-down control over prey that may increase. This range of chemical stress overturns the paradox of enrichment, a central concept in trophic cascade theory. The transition phase at the highest contamination, where the whole community collapse, exhibits multiple patterns, from smooth to abrupt, depending on external stressors and the prey population. Thus, this work provides a methodology to identify ecological traits of preys that are critical for transferring adverse effects of contaminants across the whole community.

Background\ud The eastern part of the Tibetan Plateau is now recognized as an endemic region with the highest reported human infection rates in the world of human alveolar echinococcosis (AE) caused by Echinococcus multilocularis. Existing epidemiological studies on AE have mainly focused on the synanthropic environment, while basic parasitological and ecological aspects in wildlife host species remain largely unknown, especially for small mammal hosts. Therefore, we examined small mammal host species composition, occurrence, and the prevalence of both E. multilocularis and E. shiquicus in Shiqu County (Sichuan Province, China), eastern Tibetan Plateau.\ud \ud Results\ud In total, 346 small mammals from five rodent and one pika species were trapped from four randomly set 0.25 ha square plots. Two vole species, Lasiopodomys fuscus (n = 144) and Microtus limnophilus (n = 44), and the plateau pika (Ochotona curzoniae) (n = 135), were the three most-dominant species trapped. Although protoscoleces of E. multilocularis and E. shiquicus were only observed in L. fuscus and O. curzoniae, respectively, cox1 and nad1 gene DNA of E. shiquicus was detected in all the small mammal species except for Neodon irene, whereas E. multilocularis was detected in the three most-dominant species. The overall molecular prevalence of Echinococcus species was 5.8 (95% CI: 3.3–8.2%) ~ 10.7% (95% CI: 7.4–14.0%) (the conservative prevalence to the maximum prevalence with 95% CI in parentheses), whereas for E. multilocularis it was 4.3 (95% CI: 2.2–6.5%) ~ 6.7% (95% CI: 4.0–9.3%), and 1.5 (95% CI: 0.2–2.7%) ~ 4.1% (95% CI: 2.0–6.1%) for E. shiquicus. The prevalence of both E. multilocularis and E. shiquicus, was significantly higher in rodents (mainly voles) than in pikas. Phylogenetic analyses revealed that Echinococcus haplotypes of cox1 from small mammal hosts were actively involved in the sylvatic and anthropogenic transmission cycles of E. multilocularis in the eastern Tibetan Plateau.\ud \ud Conclusions\ud In contrast to previous studies, the current results indicated that rodent species, rather than pikas, are probably more important natural intermediate hosts of E. multilocularis and E. shiquicus in the eastern Tibetan Plateau. Thus, understanding interspecific dynamics between rodents and pikas is essential to studies of the echinococcosis transmission mechanism and human echinococcosis prevention in local communities.\ud \ud Keywords:\ud Echinococcus multilocularis, E. shiquicus, Small mammal Prevalence, Tibetan Plateau

The life cycle of the cestode Echinococcus multilocularis primarily involves canids and small mammals (rodents, lagomorphs) as definitive and intermediate hosts, respectively. Several surveys have identified marked temporal and geographical variations at different scales in the parasite’s prevalence in both types of hosts, suggesting variations in the biological and ecological factors that control transmission processes. The parasite transmission from intermediate to definitive hosts is determined by the predator–prey relationship, which theoretically depends on prey population dynamics and the complex dietary response of predators to varying densities of prey species and other food items. Parasite eggs are transmitted to intermediate hosts via carnivore faeces, whose distribution in the environment is driven by the defecating behaviour of final hosts. We reviewed field-based studies that address issues related to the trophic ecology and behaviour of definitive hosts, interactions between definitive and intermediate hosts, and E. multilocularis transmission both in wild and domestic animals in rural and urban environments. Two density-dependent mechanisms control the transmission dynamics in definitive hosts: one is based on the variations in the availability of intermediate hosts, and the other is based on the variations in the density of the definitive host and its faeces. Non-linearity and the direct and delayed responses of definitive host contamination in relation to intermediate host population variations were recorded. The dietary response of the red fox was shown to be complex when abundant alternative resources were available (anthropogenic food, multiple intermediate host prey species). Micro-local hotspots of parasite transmission to intermediate hosts in a landscape, as well as areas of higher risk for human contamination in village and urban settings, may be explained by the definitive hosts’ activity patterns and defecation behaviour.

International audience; 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 693km2. 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 (585km2). 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.

International audience; Palm oil is nowadays the first vegetable oil consumed worldwide. Given the world population growth and the increasing demand in fat for food and fuel, the increase in oil palm production is expected to continue. It is thus important to find ways of reducing the ecological impact of oil palm plantations at both the agroecosystem and the mill supply area levels, by improving agricultural practices and land uses. This is where agroecology can play a very critical role. The present article gathers short stories on agroecological practices currently taking place in oil palm plantations in South-East Asia. Such stories notably highlight the importance of the various palm co-products and how appropriate recycling strategies can allow for reducing external inputs to both the field and the mill. Besides limiting environmental impacts thanks to such savings, several co-products used as organic amendments can even help to maintain or enhance soil quality. Other stories explored agroecological practices developed for biological controls. Although integrated pest management has been applied in palm plantations for a long time, the underlying mechanisms are still not fully deciphered and practices still need to be improved. More knowledge is needed in order to better account for the holistic role of biodiversity and arbitrate trade-offs between practices and ecosystem services, at both plantation and landscape levels.; L'huile de palme est aujourd'hui la première huile végétale consommée au monde. Étant donné la croissance démographique mondiale et la demande accrue en corps gras pour l'alimentation et les biocarburants, l'augmentation de la production d'huile de palme devrait perdurer. Il est ainsi primordial de trouver des moyens de production permettant de réduire l'impact écologique des plantations de palmier à huile, à la fois à l'échelle de l'agroécosystème et celle du bassin d'approvisionnement de l'huilerie, en améliorant les pratiques et la gestion des usages des sols. Les principes de l'agroécologie peuvent aider à développer des solutions à ces diverses échelles. Cet article rassemble diverses histoires courtes illustrant des pratiques agroécologiques mises en place dans des plantations de palmier à huile en Asie du Sud-Est. Ces illustrations mettent en évidence l'importance des nombreux co-produits issus du palmier et leur rôle clé dans les stratégies de recyclage pour réduire le recours aux intrants externes pour la plantation comme pour l'huilerie. Au-delà de la réduction des impacts environnementaux du fait de ces économies d'intrants, certains co-produits restitués en plantation peuvent également permettre de maintenir, voire d'améliorer, la qualité des sols. D'autres histoires courtes parcourent quelques autres pratiques agroécologiques dans le domaine de la lutte intégrée. Bien que de nombreuses pratiques de contrôle biologique soient mises en œuvre dans des plantations de palmier à huile depuis de nombreuses années, les mécanismes sous-jacents ont été encore peu explorés et les pratiques peuvent être améliorées. De nouvelles connaissances sont nécessaires pour mieux caractériser et prendre en compte de manière holistique les enjeux et le rôle de la biodiversité et pouvoir arbitrer les compromis entre pratiques et services écosystémiques, aux échelles de la plantation et du paysage.

International audience; Evolution and dispersion history on Earth of organisms can best be studied through biological markers in molecular epidemiological studies. The biological diversity of the cestode Echinococcus multilocularis was investigated in different cladistic approaches. First the morphological aspects were explored in connection with its ecology. More recently, molecular aspects were investigated to better understand the nature of the variations observed among isolates. The study of the tandemly repeated multilocus microsatellite EmsB allowed us to attain a high genetic diversity level where other classic markers have failed. Since 2006, EmsB data have been collected on specimens from various endemic foci of the parasite in Europe (in historic and newly endemic areas), Asia (China, Japan and Kyrgyzstan), and North America (Canada and Alaska). Biological data on the isolates and metadata were also recorded (e.g. host, geographical location, EmsB analysis, citation in the literature). In order to make available the data set of 1,166 isolates from classic and aberrant domestic and wild animal hosts (larval lesions and adult worms) and from human origin, an open web access interface, developed in PHP, and connected to a PostgreSQL database, was developed in the EmsB Website for the Echinococcus Typing (EWET) project. It allows researchers to access data collection, perform genetic analyses online (e.g. defining the genetic distance between their own samples and the samples in the database), consult distribution maps of EmsB profiles, and record and share their new EmsB genotyping data. In order to standardize the EmsB analyses performed in the different laboratories throughout the world, a calibrator was developed. The final aim of this project was to gather and arrange available data to permit to better understand the dispersion and transmission patterns of the parasite among definitive and intermediate hosts, in order to organize control strategies on the ground.

SUMMARYRecent changes in the epidemiology of alveolar echinococcosis (AE) in Eurasia have led to increasing concerns about the risk of human AE and the need for a thorough evaluation of the epidemiological situation. The aim of this study was to explore the use of a National Register to detect complex distribution patterns on several scales. The data were human AE cases from the FrancEchino register, diagnosed in France from 1982 to 2011. We used the Kulldorff spatial scan analysis to detect non-random locations of cases. We proposed an exploratory method that was based on the successive detection of nested clusters inside each of the statistically significant larger clusters. This method revealed at least 4 levels of disease clusters during the study period. The spatial variations of cluster location over time were also shown. We conclude that National Human AE registers, although not exempted from epidemiological biases, are currently the best way to achieve an accurate representation of human AE distribution on various scales. Finally, we confirm the multi-scale clustered distribution of human AE, and we hypothesize that our study may be a reasonable starting point from which to conduct additional research and explore the processes that underlie such distributions.

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; Echinococcus multilocularis is a common tapeworm in foxes and rodents in the northern hemisphere and the causal agent of Alveolar Echinococcosis (AE). Epidemiological discontinuities are known: highly endemic in China, in expansion in Europe and rarely described in North America. In this context, a part of the European project EchinoRisk aimed to focus on genetic diversity to explain the discrepancy amongst European foci. Moreover genetic analyses were performed to identify the parasite circulation amongst hosts in the environment on different spatial scales. A highly discriminant molecular marker was thus designed. It took ten years from the first description to the assessment of its discrimination power amongst E. multilocularis isolates from different geographical scales. The microsatellite EmsB was confirmed as a tandemly repeated sequence of about 250 bp present in about 40 copies in the parasite genome. Its original profile indicated high power of discrimination. First, regional E. multilocularis profiles were described by the analysis of EmsB in Europe, America and Asia. In Europe, the marker has permitted to distinguish a historical area surrounded by newly endemic areas. Moreover an Arctic origin was described for E. multilocularis recently discovered in Svalbard Island (Norway). In order to better understand its transmission pathway to human, a genotyping project on European AE has been started. The first results suggest a contamination in the close environment of the patient. In this context, an international EmsB database has been implemented in the EWET project (“EmsB Website for Echinococcus Typing”), comprising about 1200 genotyped E. multilocularis samples, to compare a new isolate to a reference collection. The next step after EmsB, will focus on large screening in the parasite genome. As regards to performances in Next Generation Sequencing technologies, whole-genome sequencing first based on EmsB profiles previously described have to be performed to highlight genes or groups of genes presenting variations and potentially could explain the different phenotypes or forms of pathogenicity encountered in intermediate hosts, among a European panel of samples tested. This panel can be also tested for phylogenetic studies in Europe to challenge EmsB.

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.

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 km2 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 (1Db) and the lowest area coverage. Within habitat 1Db was larger than landscape 1Db, 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.

The diet of the Barn Owl ( Tyto alba (Scopoli, 1769)) was studied over an 8-year period in the Jura mountains of France, during two population surges of its main rodent prey (common voles, Microtus arvalis (Pallas, 1778), and European water voles, Arvicola terrestris (L.,1758)), allowing us to test whether T. alba is an opportunistic predator as is often cited in the literature or exhibits more complex patterns of prey selection as is reported in arid environments. Small mammals were sampled by trapping and index methods. We observed (i) significant correlations between the proportions of A. terrestris, M. arvalis, and woodland rodents in the diet and their respective densities in the field; (ii) interactions between populations of A. terrestris and M. arvalis, indicating that the proportion of each species in diet was affected by the density of the other; (iii) proportions of red-toothed shrews (genus Sorex (L., 1758)) in the diet did not correlate with their abundance in the field, indicating that those species were likely to be preyed upon when others were no longer available. This confirms that T. alba is generally opportunistic; however, prey selection of a focal species (e.g., Sorex spp., grassland species) can be affected by the density or availability of the other prey species.

In order to identify the respective importance of the ecological and biological factors involved in the transmission ofEchinococcus multilocularis, we estimated grassland vole intermediate host (Microtussp. andArvicola terrestris) population densities, in relation to the diet of the definitive host (red fox,Vulpes vulpes) and with the prevalence ofE. multilocularisin the fox population. The study was conducted in the Ardennes, north-eastern France, which is an area with a high incidence of alveolar echinococcosis. Surface index methods showed thatMicrotuswas the most abundant intermediate host in the area. Furthermore,Microtuswas present in one-third of the 144 faeces and 98 stomach content samples examined and represented more than two-thirds of the rodent occurrences. Red fox predation onMicrotuswas significantly correlated withMicrotusrelative abundance. In contrast, the relative abundance ofA. terrestriswas very low. This species, as well asClethrionomys glareolusandApodemussp., was little consumed.E. multilocularisprevalence in foxes was determined from carcasses and reached 53% (95% confidence interval 45–61%). Intensity of infection varied from 2 to 73,380 worms per fox, with 72% of the sampled worm burden harboured by 8% of the sampled foxes. The selected explanatory variables (sex, year, age class, health and nutritional condition, and season) failed to predict prevalence rate and worm burden. The high prevalence rate in foxes indicates the possibility of intenseE. multilocularistransmission, apart from periods, or in landscapes, favourable to large population outbreaks of grassland rodents.

Alveolar echinococcosis is restricted geographically to the colder areas of the northern hemisphere. In France, the highest prevalence is observed in Franche-Comtd. The yearly incidence of AE in endemic areas is generally low (0.02-0.18 per 100,000 inhabitants) but it can exceed 1 per 100,000 locally. E. multilocularis transmission has intensified in traditionally in foxes endemic areas during the last twenty years, and the parasite has extended its range to new areas and countries of Europe. The increasing proximity of fox populations to urban areas may lead to a new epidemiological pattern. Control measures are only applicable at the local scale, and are essentially based on for deworming.

International audience; Echinococcus multilocularis is the causative agent of human Alveolar Echinococcosis (AE), and it is one of the most lethal zoonotic infections in the Northern Hemisphere. In France, the eastern and central regions are endemic areas; Franche-Comt?Lorraine and Auvergne are particularly contaminated. Recently, several human cases were recorded in the French Ardennes area, a region adjacent to the western border of the E. multilocularis range in France. A previous study in this focus described a prevalence of over 50% of the parasite in red foxes. The present study investigated the genetic diversity of adult worms collected from foxes in a 900km(2) area in the Ardennes. Instead of a conventional mitochondrial target (ATP6), two microsatellite targets (EmsB and NAK1) were used. A total of 140 adult worms isolated from 25 red foxes were genotyped. After hierarchical clustering analyses, the EmsB target enabled us to distinguish two main assemblages, each divided into sub-groups, yielding the differentiation of six clusters or assemblage profiles. Thirteen foxes (52% of the foxes) each harbored worms from at least two different assemblage profiles, suggesting they had become infected by several sources. Using the NAK1 target, we identified 3 alleles, two found in association with the two EmsB assemblages. With the NAK1 target, we investigated the parasite breeding system and the possible causes of genetic diversification. Only one fox harbored hybrid worms, indicative of a possible (and rare) occurrence of recombination, although multiple infections have been observed in foxes. These results confirm the usefulness of microsatellite targets for assessing genetic polymorphism in a geographically restricted local range.

International audience; The completion of the life cycle of Echinococcus multilocularis needs a spatial overlap between intermediate host species (voles) and definitive host (fox) faeces. Factors influencing the importance of this overlap were investigated in north eastern France. Kilometric transects were walked to collect fox faeces and to estimate vole relative densities through surface indices. Habitat and climatic conditions were the strongest predictors of the number of faeces collected, while vole densities had no predictive power. Densities of both Microtus sp. and fox faeces were higher in medium-height vegetation edge. The consequences of such results to understand local transmission processes and human exposure are discussed.

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 analysis.

International audience; Multi-host trophically transmitted parasite (TTP) is a common life cycle where prey and predators are respectively intermediate and definitive hosts of the parasite. In these systems, the foraging response of the predator toward variations in prey community composition underlies the dynamic of the parasite. Therefore, modeling epidemiological dynamic of infectious diseases considering ecological predator–prey interactions is essential to understand the spreading of parasites in ecosystems. However, two important weaknesses of previous TTP models including feeding interaction can be pointed out: (i) the choice of a linear density-dependent contact rate is faintly realistic as it supposes an unlimited ingestion rate with an increase of prey density and (ii) considering only one host prey species prevents the study of host biodiversity effect due to change in the prey community composition where species have different competences to be infected and to transmit the parasite. This article attempts to address the dynamics of parasite in a context of multiple intermediate hosts differentiated by their competences and of complex foraging behavior of the predator. We present and analyze a deterministic one predator-two prey model, which is then used to explore the transmission cycle of the cestode Echinococcus multilocularis . This study examines the foraging condition for the co-existence of the prey, and then, based on the computation of the threshold measure of disease risk, R0R0, we show that the pattern of feeding interactions changes the relationship between disease risk and prey community composition. Finally, we disentangle the mechanism leading to the counter-intuitive observation of a decrease of disease risk while the population density of intermediate hosts increases.

International audience; The ability for a generalist consumer to adapt its foraging strategy (the multi-species functional response, MSFR) is a milestone in ecology as it contributes to the structure of food webs. The trophic interaction between a generalist predator, as the red fox or the barn owl, and its prey community, mainly composed of small mammals, has been empirically and theoretically widely studied. However, the extent to which these predators adapt their diet according to both multi-annual changes in multiple prey species availability (frequency dependence) and the variation of the total prey density (density dependence) is unexplored.We provide a new general model of MSFR disentangling changes in prey preference according to variation of prey frequency (switching) and of total prey density (we propose the new concept of “rank switching”). We apply these models to two large data sets of red fox and barn owl foraging. We show that both frequency-dependent and density-dependent switching are critical properties of these two systems, suggesting that barn owl and red fox have an accurate image of the prey community in terms of frequency and absolute density. Moreover, we show that negative switching, which can lead to prey instability, is a strong property of the two systems.

International audience; For sustainable oil palm production, barn owl (Tyto alba) predation should be enhanced and monitored to better understand its impact on rodent population dynamics, notably for selective predation based on age or size. Our aim was to assess the best combination of osteometric variables that predict eye lens weight and thus the relative age of an individual Rattus tiomanicus based on pellet remains. We captured 161 individuals in an oil palm plantation in Indonesia and measured 15 osteometric variables for the jaw, skull, and femur. We investigated the variables’ correlations with eye lens weight and estimated the measurement errors. In addition, 120 pellets were collected to assess the frequency of different types of bones. Predictive modelling was then used. We suggest that the model using the femur length would be more appropriate, even if it is slightly less precise than the models that consider the skull and jaw variables. The femur was well represented in the pellet sample, its length highly correlated with the eye lens weight, with a low measurement error. Our study demonstrates the utility of femur length for age prediction in prey from macroremains in oil palm plantations, wherein most pellets are headless and R. tiomanicus is the dominant prey.

International audience; : The oncosphere stage of Echinococcus multilocularis in red fox stools can lead, after ingestion, to the development of alveolar echinococcosis in the intermediate hosts, commonly small mammals and occasionally humans. Monitoring animal infection and environmental contamination is a key issue in public health surveillance. We developed a quantitative real-time PCR technique (qPCR) to detect and quantify E. multilocularis DNA released in fox faeces. A qPCR technique using a hydrolysis probe targeting part of the mitochondrial gene rrnL was assessed on (i) a reference collection of stools from 57 necropsied foxes simultaneously investigated using the segmental sedimentation and counting technique (SSCT) (29 positive for E. multilocularis worms and 28 negative animals for the parasite); (ii) a collection of 114 fox stools sampled in the field: two sets of 50 samples from contrasted endemic regions in France and 14 from an E. multilocularis-free area (Greenland). Of the negative SSCT controls, 26/28 were qPCR-negative and two were weakly positive. Of the positive SSCT foxes, 25/29 samples were found to be positive by qPCR. Of the field samples, qPCR was positive in 21/50 (42%) and 5/48 (10.4%) stools (2 samples inhibited), originating respectively from high and low endemic areas. In faeces, averages of 0.1pg/μl of DNA in the Jura area and 0.7pg/μl in the Saône-et-Loire area were detected. All qPCR-positive samples were confirmed by sequencing. The qPCR technique developed here allowed us to quantify environmental E. multilocularis contamination by fox faeces by studying the infectious agent directly. No previous study had performed this test in a one-step reaction.

International audience; : Alveolar echinococcosis, caused by the cestode Echinococcus multilocularis, is the most serious parasitic disease for humans in Europe, with a sylvatic life cycle generally between small rodents and red foxes. General expansion of the range of E. multilocularis has been observed across Europe over the last 15years. In France, a westward spread of the known endemic areas of the parasite was described recently. For genotyping, the microsatellite EmsB was used to trace expansion in five French areas. A total of 22 EmsB profiles were identified, with five similar to those previously described in other parts of Europe. An imbalance of genetic diversity was observed between the five areas which also revealed their interconnection with the presence of common profiles, notably the two main profiles both present in all regions except one in the North. These two findings are similar to those described at the European level, highlighting transmission of the parasite by a mainland-island system. A spatio-temporal scenario of the expansion of E. multilocularis can be proposed with spread from the French historical focus in eastern France to the Lorraine, the Champagne-Ardenne and finally the North, while simultaneously another expansion has occurred from the historical focus into the West. The colonization by the parasite into the West and North areas from the historical focus was probably due to the migration of foxes several decades ago. Recent detection of the parasite in new endemic "départements" may be due to more active research rather than a recent spread of the parasite. Regarding the numerous data obtained by the different EmsB analyses, principally across Europe, centralization of all the profiles described in a public databank appears necessary in order to obtain a precise understanding of transmission of the parasite from one country to another.

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; Our study showed that open pastures had more small mammal burrows than fenced pastures in Tibetan pastoralist communities in 2003. This characteristic was linked to a higher prevalence of Echinococcus multilocularis in dogs and indicates that pasture type may affect E. multilocularis transmission.

International audience; Partial remediation actions at a former gold mine in Southern France led to a mosaic of contaminated and rehabilitated zones. In this study, the distribution of arsenic and its potential adverse effects on small mammals were investigated. The effectiveness of remediation for reducing the transfer of this element into wildlife was also discussed. Arsenic levels were measured in the soil and in the stomach contents, livers, kidneys, and lungs of four small mammal species (the wood mouse (Apodemus sylvaticus), the Algerian mouse (Mus spretus), the common vole (Microtus arvalis), and the greater white-toothed shrew (Crocidura russula)). The animals were caught at the former extraction site, in zones with three different levels of remediation treatments, and at a control site. Arsenic concentrations in the soil were highly spatially heterogeneous (ranging from 29 to 18,900 mu g g(-1)). Despite the decrease in arsenic concentrations in the remediated soils, both wood mice and Algerian mice experienced higher oral exposure to arsenic in remediated zones than in the control area. The accumulated arsenic in their organs showed higher intra-zonal variability than the arsenic distribution in the soil, suggesting that, in addition to remediation processes, other variables can help explain arsenic transfer to wildlife, such as the habitat and diet preferences of the animals or their mobility. A weak but significant correlation between arsenic concentration and body condition was observed, and weak relationships between the liver/kidney/lung mass and arsenic levels were also detected, suggesting possible histological alterations.