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1. Unknown age in health disorders: A method to account for its cumulative effect and an application to feline viruses interactions

Author

Eléonore Hellard, Dominique Pontier, Aurélie Siberchicot, Frank Sauvage, and David Fouchet

Subjects
Felis silvestris catus, Multiple infections, Parametric boostrap, SI model, Serology, Infectious and parasitic diseases, RC109-216
Abstract

Parasite interactions have been widely evidenced experimentally but field studies remain rare. Such studies are essential to detect interactions of interest and access (co)infection probabilities but face methodological obstacles. Confounding factors can create statistical associations, i.e. false parasite interactions. Among them, host age is a crucial covariate. It influences host exposition and susceptibility to many infections, and has a mechanical effect, older individuals being more at risk because of a longer exposure time. However, age is difficult to estimate in natural populations. Hence, one should be able to deal at least with its cumulative effect. Using a SI type dynamic model, we showed that the cumulative effect of age can generate false interactions theoretically (deterministic modeling) and with a real dataset of feline viruses (stochastic modeling). The risk to wrongly conclude to an association was maximal when parasites induced long-lasting antibodies and had similar forces of infection. We then proposed a method to correct for this effect (and for other potentially confounding shared risk factors) and made it available in a new R package, Interatrix. We also applied the correction to the feline viruses. It offers a way to account for an often neglected confounding factor and should help identifying parasite interactions in the field, a necessary step towards a better understanding of their mechanisms and consequences.

Published
2015
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2. Testing epidemiological functional groups as predictors of avian haemosporidia patterns in southern Africa

Author

Eléonore Hellard, Graeme S. Cumming, Alexandre Caron, Elizabeth Coe, and Jeffrey L. Peters

Subjects
avian community, avian malaria, Haemoproteus, multihost parasites, Plasmodium, relative risk, Ecology, QH540-549.5
Abstract

Abstract Understanding the dynamics of multihost parasites and the roles of different host species in parasite epidemiology requires consideration of the whole animal community. Host communities may be composed of hundreds of interacting species, making it necessary to simplify the problem. One approach to summarizing the host community in a way that is relevant to the epidemiology of the parasite is to group host species into epidemiological functional groups (EpiFGs). We used EpiFGs to test our understanding of avian malaria (Plasmodium and Haemoproteus) dynamics in four communities of wetland‐associated birds in southern Africa. Bird counts and captures were undertaken every 2–4 months over 2 yr and malaria was diagnosed by nested PCR. One hundred and seventy‐six bird species were allocated to a set of EpiFGs according to their assumed roles in introducing and maintaining the parasite in the system. Roles were quantified as relative risks from avian foraging, roosting, and movement ecology and assumed interaction with vector species. We compared our estimated a priori risks to empirical data from 3414 captured birds from four sites and 3485 half‐hour point counts. After accounting for relative avian abundance, our risk estimates significantly correlated with the observed prevalence of Haemoproteus but not Plasmodium. Although avian roosting height (for both malarial genera) and movement ecology (for Plasmodium) separately influenced prevalence, host behavior alone was not sufficient to predict Plasmodium patterns in our communities. Host taxonomy and relative abundance were also important for this parasite. Although using EpiFGs enabled us to predict the infection patterns of only one genus of heamosporidia, our approach holds promise for examining the influence of host community composition on the transmission of vector‐borne parasites and identifying gaps in our understanding of host–parasite interactions.

Published
2016
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3. True versus false parasite interactions: a robust method to take risk factors into account and its application to feline viruses.

Author

Eléonore Hellard, Dominique Pontier, Frank Sauvage, Hervé Poulet, and David Fouchet

Subjects
Medicine, Science
Abstract

Multiple infections are common in natural host populations and interspecific parasite interactions are therefore likely within a host individual. As they may seriously impact the circulation of certain parasites and the emergence and management of infectious diseases, their study is essential. In the field, detecting parasite interactions is rendered difficult by the fact that a large number of co-infected individuals may also be observed when two parasites share common risk factors. To correct for these "false interactions", methods accounting for parasite risk factors must be used.In the present paper we propose such a method for presence-absence data (i.e., serology). Our method enables the calculation of the expected frequencies of single and double infected individuals under the independence hypothesis, before comparing them to the observed ones using the chi-square statistic. The method is termed "the corrected chi-square." Its robustness was compared to a pre-existing method based on logistic regression and the corrected chi-square proved to be much more robust for small sample sizes. Since the logistic regression approach is easier to implement, we propose as a rule of thumb to use the latter when the ratio between the sample size and the number of parameters is above ten. Applied to serological data for four viruses infecting cats, the approach revealed pairwise interactions between the Feline Herpesvirus, Parvovirus and Calicivirus, whereas the infection by FIV, the feline equivalent of HIV, did not modify the risk of infection by any of these viruses.This work therefore points out possible interactions that can be further investigated in experimental conditions and, by providing a user-friendly R program and a tutorial example, offers new opportunities for animal and human epidemiologists to detect interactions of interest in the field, a crucial step in the challenge of multiple infections.

Published
2012
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5. Domestic mammals facilitate tick-borne pathogen transmission networks in South African wildlife

Author

Eléonore Hellard, Marcela P.A. Espinaze, Graeme S. Cumming, and Ivan Gerard Horak

Subjects
0106 biological sciences, 0301 basic medicine, Agroforestry, Wildlife, Biodiversity, 010603 evolutionary biology, 01 natural sciences, Disease control, law.invention, 03 medical and health sciences, 030104 developmental biology, Transmission (mechanics), Geography, Tick borne, law, Wildlife management, Parasite transmission, Protected area, Ecology, Evolution, Behavior and Systematics, Nature and Landscape Conservation
Abstract

The South African National Biodiversity Institute's SABIF (South African Biodiversity Information Facility) digitization program and the National Research Foundation of South Africa.

Published
2018

6. More than just a corridor: A suburban river catchment enhances bird functional diversity

Author

Eléonore Hellard, Jessleena Suri, Pippin Anderson, Tristan Charles-Dominique, and Graeme S. Cumming

Subjects
0106 biological sciences, geography, geography.geographical_feature_category, Ecology, National park, 010604 marine biology & hydrobiology, Drainage basin, Biodiversity, Management, Monitoring, Policy and Law, Urban area, 010603 evolutionary biology, 01 natural sciences, Ecosystem services, Urban Studies, Habitat, Urbanization, Microcosm, Nature and Landscape Conservation
Abstract

Globally, as trends of urbanisation continue to intensify, there has been increasing concern over the impacts of urban expansion on biodiversity and greater attention towards addressing these impacts. Ecological infrastructure such as urban rivers and their catchments may enhance biodiversity, ecological functioning and ecosystem service delivery within cities. Birds are good indicators of urban habitat quality because their ecology is well-studied and they are habitat selective. This study assesses the ecological value of a small urban river catchment in Cape Town, South Africa, in terms of its effect on the taxonomic and functional diversity of birds. 178 bird counts were carried out at 89 sites and 95 species were recorded. The nine functional groups considered were present in equal proportions in the catchment and in the whole of southern Africa, making the catchment a microcosm of the region’s avifauna in terms of functional composition. Using RLQ and fourth-corner analyses, we showed that the river was responsible for the occurrence of certain species and functional groups that would not otherwise occur in the suburbs. Nutrient movers, insectivores, scavengers and seed dispersers responded strongly to a gradient of distance from the river and the position on the river. Contrary to the homogenised assemblage that might be expected of an urban area, the catchment contains a taxonomically and functionally diverse bird assemblage. The combination of a river, a heterogeneous urban matrix and an adjacent national park makes this catchment an exemplar of the value of ecological infrastructure for urban biodiversity.

Published
2017

7. Analysis of large new South African dataset using two host-specificity indices shows generalism in both adult and larval ticks of mammals

Author

Graeme S. Cumming, Marcela P.A. Espinaze, Eléonore Hellard, and Ivan Gerard Horak

Subjects
0106 biological sciences, 0301 basic medicine, Tick infestation, Range (biology), Tick, medicine.disease_cause, Generalist and specialist species, 010603 evolutionary biology, 01 natural sciences, Host Specificity, Host-Parasite Interactions, South Africa, 03 medical and health sciences, Ticks, parasitic diseases, Infestation, medicine, Animals, Juvenile, Mammals, biology, Ecology, Host (biology), bacterial infections and mycoses, biology.organism_classification, medicine.disease, Tick Infestations, 030104 developmental biology, Infectious Diseases, Larva, Animal Science and Zoology, Parasitology, Ixodidae
Abstract

SUMMARYTicks and tick-borne pathogens can have considerable impacts on the health of livestock, wildlife and people. Knowledge of tick–host preferences is necessary for both tick and pathogen control. Ticks were historically considered as specialist parasites, but the range of sampled host species has been limited, infestation intensity has not been included in prior analyses, and phylogenetic distances between hosts have not been previously considered. We used a large dataset of 35 604 individual collections and two host-specificity indices to assess the specificity of 61 South African tick species, as well as distinctions between adult and juvenile ticks, for 95 mammalian hosts. When accounting for host phylogeny, most adult and juvenile ticks behaved as generalists, with juveniles being significantly more generalist than adults. When we included the intensity of tick infestation, ticks exhibited a wider diversity of specificity in all life stages. Our results show that ticks of mammals in South Africa tend to behave largely as generalists and that adult ticks are more host-specific. More generally, our analysis shows that the incorporation of life-stage differences, infestation intensity and phylogenetic distances between hosts, as well as the use of more than one specificity index, can all contribute to a deeper understanding of host–parasite interactions.

Published
2015

8. A social–ecological approach to landscape epidemiology: geographic variation and avian influenza

Author

Alexandre Caron, Eléonore Hellard, John Duncan Grewar, Dominic A. W. Henry, Celia Abolnik, Chevonne Reynolds, Graeme S. Cumming, and Nicolas Gaidet

Subjects
Geography, Planning and Development, L73 - Maladies des animaux, medicine.disease_cause, Analyse de système, Interactions biologiques, Grippe aviaire, Ecology, Environmental resource management, Animal domestique, B10 - Géographie, Épidémiologie, Maladie des animaux, Identification (biology), L20 - Écologie animale, L72 - Organismes nuisibles des animaux, Écologie, F40 - Écologie végétale, Distribution géographique, Landscape epidemiology, Ecology (disciplines), Biology, Ecological psychology, medicine, Influenzavirus aviaire, Transmission des maladies, Nature and Landscape Conservation, Paysage, Land use, business.industry, Étude de cas, Oiseau, Animal sauvage, Influenza A virus subtype H5N1, Field (geography), Sociologie, Landscape ecology, business
Abstract

Erratum paru dans Landscape Ecology (2015) 30 p. 987. http://dx.doi.org/10.1007/s10980-015-0204-6. Context Landscape structure influences host-parasite- pathogen dynamics at multiple scales in space and time. Landscape epidemiology, which connects disease ecology and landscape ecology, is still an emerging field. Objective We argue that landscape epidemiology must move beyond simply studying the influence of landscape configuration and composition on epidemiological processes and towards amore comparative, systems approach that better incorporates social-ecological complexity. Methods We illustrate our argument with a detailed review, based on a single conceptual systems model, of geographic variation in drivers of avian influenza in Western Europe, Southeast Asia, and Southern Africa. Results Our three study regions are similar in some ways but quite different in others. The same underlying mechanisms apply in all cases, but differences in the attributes of key components and linkages (most notably avian diversity, the abiotic environment, land use and land cover, and food production systems) create significant differences in avian influenza virus prevalence and human risk between regions. Conclusions Landscape approaches can connect local- and continental-scale elements of epidemiology. Adopting a landscape-focused systems perspective on the problem facilitates the identification of the most important commonalities and differences, guiding both science and policy, and helps to identify elements of the problem on which further research is needed. More generally, our review demonstrates the importance of social-ecological interactions and comparative approaches for landscape epidemiology.

Published
2015

9. When cats’ ways of life interact with their viruses: A study in 15 natural populations of owned and unowned cats (Felis silvestris catus)

Author

Eléonore Hellard, Dominique Pontier, B. Tarin, C. Coupier, David Fouchet, Hervé Poulet, V. Badol, Guillaume Leblanc, Hugues Santin-Janin, Ecoépidémiologie évolutionniste, Département écologie évolutive [LBBE], Laboratoire de Biométrie et Biologie Evolutive - UMR 5558 (LBBE), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS)-Laboratoire de Biométrie et Biologie Evolutive - UMR 5558 (LBBE), and Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Male, Rural Population, 0106 biological sciences, Veterinary medicine, Feline immunodeficiency virus, 040301 veterinary sciences, [SDV]Life Sciences [q-bio], viruses, Population, Animals, Wild, Immunodeficiency Virus, Feline, Antibodies, Viral, Cat Diseases, 010603 evolutionary biology, 01 natural sciences, Feline leukemia virus, Virus, Serology, 0403 veterinary science, Food Animals, Risk Factors, Seroepidemiologic Studies, Animals, education, Herpesviridae, education.field_of_study, Feline calicivirus, CATS, biology, Leukemia Virus, Feline, Felis, Pets, 04 agricultural and veterinary sciences, biology.organism_classification, Logistic Models, Virus Diseases, Cats, Female, Animal Science and Zoology, France, Feline Panleukopenia Virus, Calicivirus, Feline
Abstract

In natural populations, virus circulation is influenced by host behavior and physiological characteristics. Cat populations exhibit a great variability in social and spatial structure, the existence of different ways of life within a same population may also result in different epidemiological patterns. To test this hypothesis, we used a logistic regression to analyze the risk factors of Feline immunodeficiency virus (FIV), feline herpes virus (FHV), feline calicivirus (FCV), and feline parvovirus (FPV) infection in owned (fed and sheltered) and unowned (neither fed nor sheltered, unsocialized) cats living in a rural environment in the North Eastern part of France. A serological survey was carried out in 492 non-vaccinated and non-sterilized individuals from 15 populations living in the same area. The prevalence of feline leukemia virus (FeLV) was also studied, but too few were infected to analyze the risk factors of this virus. For each virus, the epidemiological pattern was different in owned and unowned cats. Unowned cats were more frequently infected by directly transmitted viruses like FIV, FHV and FCV (21.22%, 67.66%, 86.52% in unowned cats vs 9.55%, 53.88%, 77.18% in owned cats, respectively), a difference that may be explained by a more solitary and more aggressive behavior in unowned adults, and/or possibly by a higher sensitivity related to a more stressful life. On the contrary, owned cats were more frequently infected with FPV (36.41% in owned cats vs 15.61% in unowned cats), possibly as a result of their concentration around human settlements. The present study showed that owned and unowned cats living in a same area have behavioral and physiological characteristics sufficiently different to influence virus circulation. Pooling different types of cats in a single sample without taking it into account could give a wrong picture of the epidemiology of their viruses. The conclusion of this work can be extended to any epidemiological studies led in wildlife species with flexible behavior as any variations in social or spatial structure, between or within populations, could result in different virus circulation.

Published
2011

10. Parasite-Parasite Interactions in the Wild: How To Detect Them?

Author

David Fouchet, Fabrice Vavre, Dominique Pontier, Eléonore Hellard, Ecoépidémiologie évolutionniste, Département écologie évolutive [LBBE], Laboratoire de Biométrie et Biologie Evolutive - UMR 5558 (LBBE), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS)-Laboratoire de Biométrie et Biologie Evolutive - UMR 5558 (LBBE), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS), Equipe de recherche européenne en algorithmique et biologie formelle et expérimentale (ERABLE), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), Génétique et évolution des interactions hôtes-parasites, and Département génétique, interactions et évolution des génomes [LBBE] (GINSENG)

Subjects
education.field_of_study, Host (biology), Ecology, [SDV]Life Sciences [q-bio], Parasitic Diseases, Animal, Population, Animals, Wild, Biology, Wildlife disease, Cascade effect, Host-Parasite Interactions, Infectious Diseases, Parasite hosting, Animals, Humans, Lower cost, Parasites, Parasitology, education, Ecosystem
Abstract

International audience; Inter-specific interactions between parasites impact on parasite intra-hostdynamics, host health, and disease management. Identifying and understandinginteraction mechanisms in the wild is crucial for wildlife disease management.It is however complex because several scales are interlaced. Parasite–parasite interactions are likely to occur via mechanisms at the within-host level,but also at upper levels (host population and community). Furthermore, interactionsoccurring at one level of organization spread to upper levels throughcascade effects. Even if cascade effects are important confounding factors, weargue that we can also benefit from them because upper scales often provide away to survey a wider range of parasites at lower cost. New protocols andtheoretical studies (especially across scales) are necessary to take advantage ofthis opportunity.

Published
2014

11. Differential association between circulating testosterone and infection risk by several viruses in natural cat populations: a behavioural-mediated effect?

Author

Eléonore Hellard, David Fouchet, Alexia Mouchet, Dominique Pontier, Hervé Poulet, Benjamin Rey, Ecoépidémiologie évolutionniste, Département écologie évolutive [LBBE], Laboratoire de Biométrie et Biologie Evolutive - UMR 5558 (LBBE), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS)-Laboratoire de Biométrie et Biologie Evolutive - UMR 5558 (LBBE), and Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Male, 0106 biological sciences, Feline immunodeficiency virus, Infection risk, [SDV]Life Sciences [q-bio], Population, MESH: Testosterone, Context (language use), Immunodeficiency Virus, Feline, Cat Diseases, 010603 evolutionary biology, 01 natural sciences, MESH: Regression Analysis, 03 medical and health sciences, Risk Factors, Immunity, MESH: Herpesviridae, MESH: Risk Factors, MESH: Behavior, Animal, Animals, Testosterone, MESH: Animals, education, Herpesviridae, 030304 developmental biology, 0303 health sciences, education.field_of_study, Feline calicivirus, Behavior, Animal, biology, Host (biology), MESH: Cat Diseases, Testosterone (patch), MESH: Calicivirus, Feline, biology.organism_classification, MESH: Male, MESH: Virus Diseases, Infectious Diseases, Virus Diseases, Immunology, MESH: Immunodeficiency Virus, Feline, Cats, Regression Analysis, Animal Science and Zoology, Parasitology, MESH: Cats, Calicivirus, Feline
Abstract

SUMMARYTestosterone is involved in the development and expression of physiological, morphological and behavioural traits. High levels are often associated with high infection risk and/or intensity, suggesting a trade-off between sexual traits and immunity. Classically invoked mechanisms are immunological or behavioural, i.e., testosterone increases susceptibility or resistance to parasites via an impact on immunity or modulates behaviours involved in parasite transmission. However, studies report contrasted patterns. Given its modes of action and the diversity of host-parasite interactions, testosterone should not act similarly on all interactions. To reduce host and context diversity, we studied 3 viruses in the same cat population: the aggressively transmitted Feline Immunodeficiency virus (FIV), and the Feline Calicivirus (FCV) and Herpesvirus (FHV) both transmitted during friendly contacts. Testosterone had a strong effect on the probability of being positive to FIV whereas its effect was significantly weaker on FCV and FHV. These findings demonstrate that testosterone can be differentially associated with parasites of the same type (viruses). The difference we observed was consistent with a behavioural-mediated effect (increased aggressiveness), supporting the idea that the testosterone effect on infection risk is at least partially driven by behavioural mechanisms in our system. Further investigations (e.g., individual immunity measures) are required to confirm this hypothesis.

Published
2013

12. Prevalence, genomic and metabolic profiles of Acinetobacter and Asaia associated with field-caught Aedes albopictus from Madagascar

Author

Eléonore Hellard, Fara Nantenaina Raharimalala, Patrick Mavingui, Guillaume Minard, Claire Valiente Moro, Pierre Ravelonandro, Florence Hélène Tran, Laboratoire d'Ecologie Microbienne - UMR 5557 (LEM), Institut National de la Recherche Agronomique (INRA)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Ecole Nationale Vétérinaire de Lyon (ENVL), Université de Lyon-Université de Lyon-Ecole Nationale Vétérinaire de Lyon (ENVL)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS), Ecoépidémiologie évolutionniste, Département écologie évolutive [LBBE], Laboratoire de Biométrie et Biologie Evolutive - UMR 5558 (LBBE), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS)-Laboratoire de Biométrie et Biologie Evolutive - UMR 5558 (LBBE), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS), Centre National de Recherche sur l'Environnement (CNRE), Centre National de la Recherche Scientifique, La Region Rhone-Alpes, [FRB-CD-AOOI-07-10], Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Vétérinaire de Lyon (ENVL)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de la Recherche Agronomique (INRA)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS), Centre National de Recherche sur l'Environnement, Centre National de recherche sur l'environnement, Ecologie microbienne ( EM ), Centre National de la Recherche Scientifique ( CNRS ) -Ecole Nationale Vétérinaire de Lyon ( ENVL ) -Université Claude Bernard Lyon 1 ( UCBL ), Université de Lyon-Université de Lyon-Institut National de la Recherche Agronomique ( INRA ) -VetAgro Sup ( VAS ), Laboratoire de Biométrie et Biologie Evolutive ( LBBE ), Université Claude Bernard Lyon 1 ( UCBL ), and Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique ( Inria ) -Centre National de la Recherche Scientifique ( CNRS )

Subjects
Male, MESH: Sequence Analysis, DNA, MESH : Acetobacteraceae, MESH : Genome Size, [SDV]Life Sciences [q-bio], INSECTS, DIVERSITY, Applied Microbiology and Biotechnology, genomic diversity, MESH: Madagascar, MESH: Genome Size, Genome Size, Aedes, RNA, Ribosomal, 16S, MESH : DNA, Bacterial, MESH : Female, WOLBACHIA, MESH: Animals, MESH: Genetic Variation, MESH: Phylogeny, Phylogeny, ComputingMilieux_MISCELLANEOUS, 0303 health sciences, Ecology, biology, Acinetobacter, MESH : Metabolome, MESH: Genomics, Genomics, MESH: Aedes, symbiosis, Electrophoresis, Gel, Pulsed-Field, MESH: RNA, Ribosomal, 16S, MESH: Electrophoresis, Gel, Pulsed-Field, MESH: Acinetobacter, CALCOACETICUS, Acetobacteraceae, Metabolome, Wolbachia, Female, MESH: Metabolome, Plasmids, DNA, Bacterial, Aedes albopictus, DENGUE, MESH : Acinetobacter, MESH : Madagascar, MESH : Male, ACETIC-ACBACTERIA, asian tiger mosquito, Microbiology, Bacterial genetics, 03 medical and health sciences, AEGYPTI, MESH : Genetic Variation, MESH: Plasmids, parasitic diseases, Pulsed-field gel electrophoresis, Madagascar, Animals, Genome size, acetic bacteria, MOSQUITO VECTOR, metabolic repertoire, MESH : Aedes, MESH : Electrophoresis, Gel, Pulsed-Field, 030304 developmental biology, [ SDV ] Life Sciences [q-bio], 030306 microbiology, MESH : Genomics, fungi, MESH : Phylogeny, Genetic Variation, Sequence Analysis, DNA, MESH: Acetobacteraceae, DEGRADATION, biology.organism_classification, 16S ribosomal RNA, MESH: DNA, Bacterial, MESH: Male, MESH : RNA, Ribosomal, 16S, MESH : Plasmids, Vector (epidemiology), MESH : Animals, MESH: Female, PLASMID, MESH : Sequence Analysis, DNA
Abstract

International audience; The presence of cultivable bacteria Acinetobacter and Asaia was recently demonstrated in the mosquito vector Aedes albopictus. However, it is not known how prevalent these bacteria are in field populations. Here, the presence of these bacteria in Ae. albopictus populations from Madagascar was diagnosed by amplification of 16S rRNA gene fragments. Both genera were detected at relatively high frequencies, 46% for Asaia and 74% for Acinetobacter. The prevalence of Acinetobacter correlated significantly with mosquito gender, and the prevalence of Asaia with the interaction between mosquito gender and the sampling site. For each bacterial genus, more male than female mosquitoes were infected. Using pulse field gel electrophoresis, no significant difference in genome size was found between Acinetobacter isolates from mosquitoes compared with free-living Acinetobacter. However, a great diversity was observed in plasmid numbers (from 1 to 12) and sizes (from < 8 to 690 kb). Mosquito isolates utilized fewer substrates than free-living isolates, but some substrates known as blood or plant components were specifically utilized by mosquito isolates. Therefore it is likely that a specific subpopulation of Acinetobacter is selected by Ae. albopictus. Overall, this study emphasizes the need to gain a global view on the bacterial partners in mosquito vectors.

Published
2013

13. Biogeography of the two major arbovirus mosquito vectors, Aedes aegypti and Aedes albopictus (Diptera, Culicidae), in Madagascar

Author

Fara Nantenaina Raharimalala, Karima Zouache, Pierre Ravelonandro, Anna-Bella Failloux, Lala Sahondra Rafarasoa, Lala Harivelo Ravaomanarivo, Bakoly Olga Ralisoa, Claire Valiente Moro, Van Tran-Van, Patrick Mavingui, Eléonore Hellard, Laurence Mousson, Département d'Entomologie, Facultés des Sciences d'Antananarivo, Ecologie microbienne ( EM ), Centre National de la Recherche Scientifique ( CNRS ) -Ecole Nationale Vétérinaire de Lyon ( ENVL ) -Université Claude Bernard Lyon 1 ( UCBL ), Université de Lyon-Université de Lyon-Institut National de la Recherche Agronomique ( INRA ) -VetAgro Sup ( VAS ), Centre National de Recherche sur l'Environnement, Centre National de recherche sur l'environnement, Arbovirus et Insectes Vecteurs, Institut Pasteur [Paris], Laboratoire de Biométrie et Biologie Evolutive ( LBBE ), Université Claude Bernard Lyon 1 ( UCBL ), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique ( Inria ) -Centre National de la Recherche Scientifique ( CNRS ), This work was funded by the grant FRB-CD-AOOI-07- 012, and was carried out within the frameworks of GDRI 'Biodiversité et Développement Durable à Madagascar' and COST action F0701 'Arthropod Symbioses: from fundamental to pest disease management'., Université d'Antananarivo, Laboratoire d'Ecologie Microbienne - UMR 5557 (LEM), Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Vétérinaire de Lyon (ENVL)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de la Recherche Agronomique (INRA)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS), Ecoépidémiologie évolutionniste, Département écologie évolutive [LBBE], Laboratoire de Biométrie et Biologie Evolutive - UMR 5558 (LBBE), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS)-Laboratoire de Biométrie et Biologie Evolutive - UMR 5558 (LBBE), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS), Institut National de la Recherche Agronomique (INRA)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Ecole Nationale Vétérinaire de Lyon (ENVL), Centre National de Recherche sur l'Environnement (CNRE), Arbovirus et Insectes Vecteurs - Arboviruses and Insect Vectors, Université de Lyon-Université de Lyon-Ecole Nationale Vétérinaire de Lyon (ENVL)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS), and Institut Pasteur [Paris] (IP)

Subjects
Male, Aedes albopictus, viruses, Molecular Sequence Data, 030231 tropical medicine, Zoology, Aedes aegypti, medicine.disease_cause, DNA, Mitochondrial, Arbovirus, Dengue fever, lcsh:Infectious and parasitic diseases, 03 medical and health sciences, 0302 clinical medicine, Aedes, [SDV.MHEP.MI]Life Sciences [q-bio]/Human health and pathology/Infectious diseases, Madagascar, medicine, Animals, lcsh:RC109-216, Chikungunya, 030304 developmental biology, 0303 health sciences, biology, Ecology, Research, fungi, Outbreak, virus diseases, NADH Dehydrogenase, Sequence Analysis, DNA, medicine.disease, biology.organism_classification, 3. Good health, Phylogeography, [ SDV.MHEP.MI ] Life Sciences [q-bio]/Human health and pathology/Infectious diseases, Infectious Diseases, Vector (epidemiology), Cyclooxygenase 1, Female, Parasitology, SDV:MHEP:MI, Chikungunya virus, Entomology
Abstract

Background In the past ten years, the Indian Ocean region has been the theatre of severe epidemics of chikungunya and dengue. These outbreaks coincided with a high increase in populations of Aedes albopictus that outcompete its sister taxon Aedes aegypti in most islands sampled. The objective of this work was to update the entomological survey of the two Aedes species in the island of Madagascar which has to face these arboviroses. Methods The sampling of Aedes mosquitoes was conducted during two years, from October 2007 to October 2009, in fifteen localities from eight regions of contrasting climates. Captured adults were identified immediately whereas immature stages were bred until adult stage for determination. Phylogenetic analysis was performed using two mtDNA genes, COI and ND5 and trees were constructed by the maximum likelihood (ML) method with the gene time reversible (GTR) model. Experimental infections with the chikungunya virus strain 06.21 at a titer of 107.5 pfu/mL were performed to evaluate the vector competence of field-collected mosquitoes. Disseminated infection rates were measured fourteen days after infection by immunofluorescence assay performed on head squashes. Results The species Aedes aegypti was detected in only six sites in native forests and natural reserves. In contrast, the species Aedes albopictus was found in 13 out of the 15 sites sampled. Breeding sites were mostly found in man-made environments such as discarded containers, used tires, abandoned buckets, coconuts, and bamboo cuts. Linear regression models showed that the abundance of Ae. albopictus was significantly influenced by the sampling region (F = 62.00, p < 2.2 × 10-16) and period (F = 36.22, p = 2.548 × 10-13), that are associated with ecological and climate variations. Phylogenetic analysis of the invasive Ae. albopictus distinguished haplotypes from South Asia and South America from those of Madagascar, but the markers used were not discriminant enough to discern Malagasy populations. The experimental oral infection method showed that six Ae. albopictus populations exhibited high dissemination infection rates for chikungunya virus ranging from 98 to 100%. Conclusion In Madagascar, Ae. albopictus has extended its geographical distribution whereas, Ae. aegypti has become rare, contrasting with what was previously observed. Changes are predominantly driven by human activities and the rainfall regime that provide suitable breeding sites for the highly anthropophilic mosquito Ae. albopictus. Moreover, these populations were found to be highly susceptible to chikungunya virus. In the light of this study, Ae. albopictus may have been involved in the recent outbreaks of chikungunya and dengue epidemics in Madagascar, and consequently, control measures should be promoted to limit its current expansion.

Published
2012

14. True versus false parasite interactions: a robust method to take risk factors into account and its application to feline viruses

Author

Frank Sauvage, Eléonore Hellard, Dominique Pontier, Hervé Poulet, David Fouchet, Ecoépidémiologie évolutionniste, Département écologie évolutive [LBBE], Laboratoire de Biométrie et Biologie Evolutive - UMR 5558 (LBBE), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS)-Laboratoire de Biométrie et Biologie Evolutive - UMR 5558 (LBBE), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS), and Université de Lyon

Subjects
Male, Pathology, Non-Clinical Medicine, Epidemiology, [SDV]Life Sciences [q-bio], Veterinary Microbiology, lcsh:Medicine, MESH: Logistic Models, Logistic regression, 0302 clinical medicine, Risk Factors, MESH: Risk Factors, MESH: Animals, lcsh:Science, Statistic, 0303 health sciences, Multidisciplinary, Ecology, biology, Risk of infection, 3. Good health, Community Ecology, Veterinary Diseases, Medicine, MESH: Cats, Research Article, medicine.medical_specialty, Clinical Research Design, 030231 tropical medicine, Computational biology, Microbiology, MESH: Host-Parasite Interactions, Veterinary Epidemiology, Host-Parasite Interactions, 03 medical and health sciences, Virology, Chi-square test, medicine, Animals, Humans, False Positive Reactions, Serologic Tests, Biology, 030304 developmental biology, Health Care Policy, Models, Statistical, MESH: Humans, Population Biology, MESH: False Positive Reactions, Parvovirus, lcsh:R, MESH: Serologic Tests, Computational Biology, Robustness (evolution), biology.organism_classification, MESH: Male, Logistic Models, Sample size determination, Cats, Veterinary Science, lcsh:Q, Pairwise comparison, MESH: Models, Statistical
Abstract

International audience; BACKGROUND: Multiple infections are common in natural host populations and interspecific parasite interactions are therefore likely within a host individual. As they may seriously impact the circulation of certain parasites and the emergence and management of infectious diseases, their study is essential. In the field, detecting parasite interactions is rendered difficult by the fact that a large number of co-infected individuals may also be observed when two parasites share common risk factors. To correct for these "false interactions", methods accounting for parasite risk factors must be used. METHODOLOGY/PRINCIPAL FINDINGS: In the present paper we propose such a method for presence-absence data (i.e., serology). Our method enables the calculation of the expected frequencies of single and double infected individuals under the independence hypothesis, before comparing them to the observed ones using the chi-square statistic. The method is termed "the corrected chi-square." Its robustness was compared to a pre-existing method based on logistic regression and the corrected chi-square proved to be much more robust for small sample sizes. Since the logistic regression approach is easier to implement, we propose as a rule of thumb to use the latter when the ratio between the sample size and the number of parameters is above ten. Applied to serological data for four viruses infecting cats, the approach revealed pairwise interactions between the Feline Herpesvirus, Parvovirus and Calicivirus, whereas the infection by FIV, the feline equivalent of HIV, did not modify the risk of infection by any of these viruses. CONCLUSIONS/SIGNIFICANCE: This work therefore points out possible interactions that can be further investigated in experimental conditions and, by providing a user-friendly R program and a tutorial example, offers new opportunities for animal and human epidemiologists to detect interactions of interest in the field, a crucial step in the challenge of multiple infections.

Published
2012

15. Resource gradients and movements across the edge of transfrontier parks

Author

Murwira, A., Michel De Garine-Wichatitsky, Zengeya, F., Poshiwa, X., Matema, S., Caron, A., Guerbois, C., Eléonore Hellard, Herve Fritz, Ecoépidémiologie évolutionniste, Département écologie évolutive [LBBE], Laboratoire de Biométrie et Biologie Evolutive - UMR 5558 (LBBE), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS)-Laboratoire de Biométrie et Biologie Evolutive - UMR 5558 (LBBE), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS), Ecologie quantitative et évolutive des communautés, Jens A. Andersson, Michel de Garine-Wichatitsky, David Cumming, Vupenyu Dzingirai, and Ken Giller

Subjects
Dierlijke Productiesystemen, 0106 biological sciences, Wildlife Ecology and Conservation, [SDV]Life Sciences [q-bio], 010604 marine biology & hydrobiology, WIAS, Life Science, PE&RC, 010603 evolutionary biology, 01 natural sciences, Animal Production Systems, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2012

16. When females trade grooming for grooming: testing partner control and partner choice models of cooperation in two primate species

Author

Eléonore Hellard, Sylvain Lemoine, Eric van Damme, Cécile Fruteau, Ronald Noë, Center for Economic Research, Tilburg University [Netherlands], CERCOPAN, Ecoépidémiologie évolutionniste, Département écologie évolutive [LBBE], Laboratoire de Biométrie et Biologie Evolutive - UMR 5558 (LBBE), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS)-Laboratoire de Biométrie et Biologie Evolutive - UMR 5558 (LBBE), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS), Département Ecologie, Physiologie et Ethologie (DEPE-IPHC), Institut Pluridisciplinaire Hubert Curien (IPHC), Université de Strasbourg (UNISTRA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Research Group: Economics, Department of Economics, and Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
0106 biological sciences, hierarchy, 010603 evolutionary biology, 01 natural sciences, Developmental psychology, parcelling, Cercocebus atys, time matching, biology.animal, Chlorocebus aethiops, Social grooming, 0501 psychology and cognitive sciences, Primate, 050102 behavioral science & comparative psychology, Session (computer science), Control (linguistics), Ecology, Evolution, Behavior and Systematics, Cercocebus torquatus, grooming, biology, 05 social sciences, biology.organism_classification, Social relation, biological market, raising the stakes, [SDE]Environmental Sciences, Sooty mangabey, Animal Science and Zoology, Psychology, Dyad
Abstract

International audience; We tested predictions following from the biological market paradigm using reciprocated grooming sessions among the adult females in a sooty mangabey, Cercocebus atys, group with 35 females (Ivory Coast) and in two groups of vervet monkeys, Chlorocebus aethiops (South Africa) with four and seven females, respectively. Closely ranked females often groomed frequently. The exchanges within such dyads were generally characterized by time matching, but the subordinates groomed for longer than their dominant partners. The reciprocal nature of over 90% of the grooming sessions allowed us to investigate 'partner control' strategies such as 'parcelling' and 'raising the stakes'. Females of both species neither parcelled nor gradually invested more grooming in the course of sessions. Rather, the longer bouts of a grooming session were usually at the beginning of the session and the length of the first bout reliably predicted the length of the whole session for frequently grooming partners. Furthermore, we compared potential trust-building behaviour (or 'strategies') in frequent and infrequent grooming partners. We found that infrequent groomers of both species showed no signs of trust building and that the first bout they invested in a grooming session did not predict the session length. We conclude that each female has a good knowledge of her value as a grooming partner within each dyad and knows how much she has to invest to receive a satisfactory amount of grooming within the same session.

Published
2011

17. Erratum to: A social–ecological approach to landscape epidemiology: geographic variation and avian influenza

Author

Alexandre Caron, Graeme S. Cumming, Nicolas Gaidet, Dominic A. W. Henry, John Duncan Grewar, Chevonne Reynolds, Eléonore Hellard, and Celia Abolnik

Subjects
Sustainable development, Ecology, Landscape epidemiology, Ecology (disciplines), Geography, Planning and Development, Geographic variation, medicine.disease_cause, Virology, Influenza A virus subtype H5N1, Geography, Nature Conservation, Ecological psychology, medicine, Landscape ecology, Nature and Landscape Conservation
Published
2015

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