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International audience; In the context of Epidemic Intelligence, many Event-Based Surveillance (EBS) systems have been proposed in the literature to promote the early identification and characterization of potential health threats from online sources of any nature. Each EBS system has its own surveillance definitions and priorities, therefore this makes the task of selecting the most appropriate EBS system for a given situation a challenge for end-users. In this work, we propose a new evaluation framework to address this issue. It first transforms the raw input epidemiological event data into a set of normalized events with multi-granularity, then conducts a descriptive retrospective analysis based on four evaluation objectives: spatial, temporal, thematic and source analysis. We illustrate its relevance by applying it to an Avian Influenza dataset collected by a selection of EBS systems, and show how our framework allows identifying their strengths and drawbacks in terms of epidemic surveillance.

RÉSUMÉ L’histoire nous a appris que les émergences virales ne sont pas des phénomènes nouveaux. La variole, venue d’Asie, est probablement apparue en Europe dès le Ve siècle et la fièvre jaune a émergé en Amérique au XVIe siècle, importée d’Afrique par la traite des Noirs. La dengue est apparue au XVIIIe siècle simultanément en Asie du Sud-est, en Afrique et en Amérique du Nord. Quant à la « grippe espagnole », elle a tué, en 1918–1919, entre 25 et 40 millions de personnes dans le monde. La deuxième moitié du XXe siècle a été marquée par de nombreuses émergences virales dont celle du Sida en 1981. Mais, ce qui caractérise l’évolution récente des émergences virales, c’est que non seulement de nouveaux virus émergent de façon répétée, mais qu’ils ont de plus en plus tendance à envahir de nouveaux pays, voire d’autres continents, et de s’y installer de façon plus ou moins durable. Des exemples de cette situation épidémique nouvelle sont donnés avec les infections à virus Nipah, West Nile, de la fièvre de la Vallée du Rift, du SRAS, du monkeypox, de la grippe aviaire H5N1 et Chikungunya. Les causes, multiples et complexes, de ces émergences et réémergences sont brièvement analysées.

Avian influenza outbreaks have been occurring on smallholder poultry farms in Asia for two decades. Farmer responses to these outbreaks can slow down or accelerate virus transmission. We used a longitudinal survey of 53 small-scale chicken farms in southern Vietnam to investigate the impact of outbreaks with disease-induced mortality on harvest rate, vaccination, and disinfection behaviors. We found that in small broiler flocks (≤16 birds/flock) the estimated probability of harvest was 56% higher when an outbreak occurred, and 214% higher if an outbreak with sudden deaths occurred in the same month. Vaccination and disinfection were strongly and positively correlated with the number of birds. Small-scale farmers – the overwhelming majority of poultry producers in low-income countries – tend to rely on rapid sale of birds to mitigate losses from diseases. As depopulated birds are sent to markets or trading networks, this reactive behavior has the potential to enhance onward transmission., eLife digest The past few decades have seen the circulation of avian influenza viruses increase in domesticated poultry, regularly creating outbreaks associated with heavy economic loss. In addition, these viruses can sometimes ‘jump’ into humans, potentially allowing new diseases – including pandemics – to emerge. The Mekong river delta, in southern Vietnam, is one of the regions with the highest circulation of avian influenza. There, a large number of farmers practice poultry farming on a small scale, with limited investments in disease prevention such as vaccination or disinfection. Yet, it was unclear how the emergence of an outbreak could change the behavior of farmers. To learn more, Delabouglise et al. monitored 53 poultry farms, with fewer than 1000 chickens per farm, monthly for over a year and a half. In particular, they tracked when outbreaks occurred on each farm, and how farmers reacted. Overall, poultry farms with more than 17 chickens were more likely to vaccinate their animals and use disinfection practices than smaller farms. However, disease outbreaks did not affect vaccination or disinfection practices. When an outbreak occurred, farmers with fewer than 17 chickens tended to sell their animals earlier. For instance, they were 214% more likely to send their animals to market if an outbreak with sudden deaths occurred that month. Even if they do not make as much money selling immature individuals, this strategy may allow them to mitigate economical loss: they can sell animals that may die soon, saving on feeding costs and potentially avoiding further contamination. However, as animals were often sold alive in markets or to itinerant sellers, this practice increases the risk of spreading diseases further along the trade circuits. These data could be most useful to regional animal health authorities, which have detailed knowledge of local farming systems and personal connections in the communities where they work. This can allow them to effect change. They could work with small poultry farmers to encourage them to adopt efficient disease management strategies. Ultimately, this could help control the spread of avian influenza viruses, and potentially help to avoid future pandemics.

Examining efforts to control avian influenza in Indonesia between 2005 and 2010, this article investigates why the internationally funded and designed response initially focused so much on community level “backyard” poultry farming, thus excluding, or excusing, a large and poorly regulated industrial sector from involvement in responding to disease spread and persistence. A range of biases acting on national and international agencies are identified that contributed to distorted production of knowledge and led to a focus on small farmers instead of all relevant stakeholders. These include too rapid acceptance of the intrinsic “biosafety” of industrial poultry production, a “pro-poor” development stance, the unwillingness of public and private sectors to co-ordinate, and a human rather than animal health framing. These biases were reinforced by the organisational arrangements and incentives within donor and implementing organisations. If global health emergencies are to be more effectively addressed, global and national health governance routines must better acknowledge how knowledge is produced and used in times of crisis. Passant en revue les efforts pour contrôler la grippe aviaire en Indonésie entre 2005 et 2010, le présent article examine pourquoi la réponse financée et mise au point par la communauté internationale s’est, à l’origine, essentiellement focalisée sur les petits élevages de volaille de basse-cour, excluant ou exonérant ainsi un secteur industriel important et peu réglementé de la responsabilité d’endiguer la propagation et la persistance du phénomène. Un certain nombre d’a priori pesant sur les agences nationales et internationales sont identifiés, qui ont contribué à fausser la production des connaissances et conduit à se concentrer sur les petits éleveurs plutôt que sur toutes les parties prenantes concernées. Ceci inclut l’admission trop rapide de la « biosécurité » comme inhérente à la production industrielle de volaille, le parti pris de politiques de développement axée sur les plus pauvres, l’absence de volonté de coordination des secteurs public et privé, et une définition de la santé basée plutôt sur la santé de l’homme que sur la santé animale. Ces a priori ont été renforcés par les modalités et les incitations organisationnelles propres des donateurs et des organisations chargées de la mise en œuvre. Pour traiter plus efficacement les urgences sanitaires mondiales, les procédures de gouvernance sanitaire globale et nationale doivent mieux prendre en compte la manière dont les connaissances sont produites et utilisées en temps de crise. Una vez expuestos los esfuerzos para controlar la gripe aviaria en Indonesia entre el 2005 y el 2010, el presente artículo examina la razón por la cual la respuesta financiada y elaborada por la comunidad internacional se ha enfocado, al principio, principalmente en las pequeñas ganaderías de traspatio de aves, excluyendo o exonerando de esta forma un sector industrial importante y poco reglamentado de la responsabilidad de contener la propagación y la persistencia del fenómeno. Se ha identificado un número de aprioris que pesan sobre las agencias nacionales e internacionales y que contribuyen a falsificar la producción de conocimientos. Esto condujo a una concentración sobre los pequeños ganaderos en vez de interesarse en todas las partes-interesadas dado que la producción industrial es percibida como un espacio de «bioseguridad», que existe un prejuicio de las políticas de desarrollo orientadas en los más pobres, que se observa una ausencia de voluntad de coordinación de los sectores público y privado, y que prevalece una definición de la salud basada más bien en la salud del hombre que en la salud animal. Estos aprioris han sido reforzados por las modalidades y las incitaciones organizacionales inherentes de los donadores y des las organizaciones a cargo de su ejecución. Para tratar más eficazmente las urgencias sanitarias mundiales, los procedimientos de gobernanza sanitaria global y nacional deben tomar en cuenta mejor la manera en que los conocimientos son producidos y utilizados en tiempos de crisis.

Passant en revue les efforts pour contrôler la grippe aviaire en Indonésie entre 2005 et 2010, le présent article examine pourquoi la réponse financée et mise au point par la communauté internationale s’est, à l’origine, essentiellement focalisée sur les petits élevages de volaille de basse-cour, excluant ou exonérant ainsi un secteur industriel important et peu réglementé de la responsabilité d’endiguer la propagation et la persistance du phénomène. Un certain nombre d’a priori pesant sur les agences nationales et internationales est identifié qui a contribué à fausser la production des connaissances et a conduit à se concentrer sur les petits éleveurs plutôt que sur toutes les parties prenantes concernées. Ceci inclut l’admission trop rapide de la « biosécurité » comme inhérente à la production industrielle de volaille, le parti pris de politiques de développement axées sur les plus pauvres, l’absence de volonté de coordination des secteurs public et privé, et une définition de la santé basée plutôt sur la santé de l’homme que sur la santé animale. Ces a priori ont été renforcés par les modalités et les incitations organisationnelles propres des donateurs et des organisations chargées de la mise en œuvre. Pour traiter plus efficacement les urgences sanitaires mondiales, les procédures de gouvernance sanitaire globale et nationale doivent mieux prendre en compte la manière dont les connaissances sont produites et utilisées en temps de crise. Examining efforts to control avian influenza in Indonesia between 2005 and 2010, this article investigates why the internationally funded and designed response initially focused so much on community level “backyard” poultry farming, thus excluding, or excusing, a large and poorly regulated industrial sector from involvement in responding to disease spread and persistence. A range of biases acting on national and international agencies are identified that contributed to distorted production of knowledge and led to a focus on small farmers instead of all relevant stakeholders. These include too rapid acceptance of the intrinsic “biosafety” of industrial poultry production, a “pro-poor” development stance, the unwillingness of public and private sectors to co-ordinate, and a human rather than animal health framing. These biases were reinforced by the organisational arrangements and incentives within donor and implementing organisations. If global health emergencies are to be more effectively addressed, global and national health governance routines must better acknowledge how knowledge is produced and used in times of crisis. Una vez expuestos los esfuerzos para controlar la gripe aviaria en Indonesia entre el 2005 y el 2010, el presente artículo examina la razón por la cual la respuesta financiada y elaborada por la comunidad internacional se ha enfocado, al principio, principalmente en las pequeñas ganaderías de traspatio de aves, excluyendo o exonerando de esta forma un sector industrial importante y poco reglamentado de la responsabilidad de contener la propagación y la persistencia del fenómeno. Se ha identificado un número de aprioris que pesan sobre las agencias nacionales e internacionales y que contribuyen a falsificar la producción de conocimientos. Esto condujo a una concentración sobre los pequeños ganaderos en vez de interesarse en todas las partes-interesadas dado que la producción industrial es percibida como un espacio de «bioseguridad», que existe un prejuicio de las políticas de desarrollo orientadas en los más pobres, que se observa una ausencia de voluntad de coordinación de los sectores público y privado, y que prevalece una definición de la salud basada más bien en la salud del hombre que en la salud animal. Estos aprioris han sido reforzados por las modalidades y las incitaciones organizacionales inherentes de los donadores y des las organizaciones a cargo de su ejecución. Para tratar más eficazmente las urgencias sanitarias mundiales, los procedimientos de gobernanza sanitaria global y nacional deben tomar en cuenta mejor la manera en que los conocimientos son producidos y utilizados en tiempos de crisis.

On compare ici l’usage des bases de données par des virologues et des observateurs d’oiseaux dans le contexte de la mobilisation contre la grippe aviaire à Hong Kong. Échappant au cadre étatique de centralisation du savoir, ces groupes ont participé à la constitution d’une « sentinelle », qui rend visibles les mutations des virus de grippe dans le réservoir animal. On étudie en particulier la tension entre les données codées et les images dans la communication de ce savoir, pour montrer que la base de données opère un décalage dans la production de savoir. This article compares the uses of data banks by virologists and birdwatchers during the mobilization around Avian Flu in Hong Kong. Criticizing governments who do too little or too much, these groups use data banks to understand the conditions in which viruses mutate from their animal reservoir. By constituting an environmental sentinel, these two groups link biosecurity to biodiversity, introducing techniques of “hunting” in the biopolitical world. Este articulo compara el use dos bancos de datos por virologos y observadores de aves durante la mobilisation contra la gripe aviaria in Hong Kong. Esos grupos critican gobiernos que hacen demasiado o demasiado poco por falta de información, y usen los bancos de datos para conocer las condiciones en quales viruses mutan del animal al hombre. Constituyendo una centinela por el medio ambiente, esos grupos practican una action de typo cynegenetico en el mundo pastoral de la bioseguridad.

International audience; Poultry production has significantly increased worldwide, along with the number of avian influenza (AI) outbreaks and the potential threat for human pandemic emergence. The role of wild bird movements in this global spread has been extensively studied while the role of animal, human and fomite movement within commercial poultry production and trade networks remains poorly understood. The aim of this work is to better understand these roles in relation to the different routes of AI spread. A scoping literature review was conducted according to the PRISMA guidelines (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) using a search algorithm combining twelve domains linked to AI spread and animal/human movements within poultry production and trade networks. Only 28 out of 3,978 articles retrieved dealt especially with the role of animal, human and fomite movements in AI spread within the international trade network (4 articles), the national trade network (8 articles) and the production network (16 articles). While the role of animal movements in AI spread within national trade networks has been largely identified, human and fomite movements have been considered more at risk for AI spread within national production networks. However, the role of these movements has never been demonstrated with field data, and production networks have only been partially studied and never at international level. The complexity of poultry production networks and the limited access to production and trade data are important barriers to this knowledge. There is a need to study the role of animal and human movements within poultry production and trade networks in the global spread of AI in partnership with both public and private actors to fill this gap.

Cet article interroge la capacité des experts de la grippe aviaire à prédire des pandémies de grippe à partir des mutations virales qu’ils observent chez les oiseaux. Plutôt qu’au vocabulaire du mythe ou de la prophétie, il recourt à l’anthropologie de la divination, dans la suite des analyses de Lucien Lévy-Bruhl, pour comprendre comment les mutations des virus chez les oiseaux sont perçues comme des signes des maladies catastrophiques qui peuvent affecter les humains. L’anticipation des pandémies ne repose pas sur un calcul des probabilités, comme dans la gestion des risques pour les questions de santé publique, mais sur l’imagination d’un événement catastrophique à partir de signaux d’alerte précoces. Dans le langage de l’immunologie, les sentinelles sont les outils qui permettent de percevoir ces signaux d’alerte avant que l’organisme ne réagisse de manière catastrophique. La préparation aux pandémies de grippe constitue un imaginaire moral permettant de donner sens aux signaux sur les pathogènes franchissant les barrières d’espèces, en-deçà du geste sacrificiel de l’abattage préventif., This article questions the capacity for experts in avian influenza to predict flu pandemics based on the viral mutations they observe in birds. Rather than borrowing concepts to the anthropology of myth or prophecy, the language of divination is used, following the analyses of Lucien Lévy-Bruhl, to understand how viral mutations are perceived as signs of catastrophic diseases that may affect humans. The anticipation of pandemics does not rely on a probability calculation, as in the risk management of public health, but on the imagination of a catastrophic event out of early warning signals. In the language of immunology, sentinels are devices through which these warning signals are perceived before the organism reacts in a catastrophic manner. Preparing for flu pandemics constitutes a moral imaginary that provides meaning to the signals of pathogens when they cross species barriers, below the sacrificial gesture of pre-emptive slaughter., El presente artículo indaga la capacidad de los expertos de la gripe aviaria a predecir las pandemias de gripe a partir de las mutaciones virales que observan entre los pájaros. Más que al vocabulario del mito o de la profecía, se recurre a la antropología de la adivinación, en continuidad con los análisis de Lucien Lévy-Bruhl, para comprender cómo las mutaciones de los virus entre los pájaros se perciben en tanto que signos de las enfermedades catastróficas que pueden afectar a los humanos. La anticipación de las pandemias no se basa en el cálculo de probabilidades, como sucede con la gestión de riesgos en cuestiones de salud pública, sino en la imaginación de un evento catastrófico a partir de señales de alerta precoz. En el lenguaje de la inmunología, los centinelas son las herramientas que permiten percibir dicha señales de alerta antes de que el organismo reaccione de manera catastrófica. La preparación a las pandemias de gripe constituye un imaginario moral que permite dar un significado a los indicios sobre los patógenos que atraviesan las barreras de las especies, por debajo del sacrificio de la inmolación preventiva.

Newcastle disease (ND) is endemic in West Africa, which has also experienced outbreaks of highly pathogenic avian influenza (AI) H5N1 since 2006. We aimed to estimate the prevalence and incidence of AI and ND in village poultry in Mali and to identify associated risk factors. A longitudinal serologic study was conducted between November 2009 and February 2011 using ELISA commercial kits to detect antibodies. Sera (5963) were collected from 4890 different poultry. AI was rare, with a seroprevalence of 2.9% (95% confidence interval [CI] 2.3-3.5) and a seroincidence rate of 0.7 birds per 100 bird-months at risk (95% CI 0.4-1.0). AI antibodies were short lived, with a seroreversion rate of 25.4 birds per 100 bird-months at risk (95% CI 19.0-31.7). Risk factors for AI were limited: temporal variation occurred, but proximity to a water body was a risk factor only when large populations of wild waterbirds were present. ND was very common, with seroprevalence of 68.9% (95% CI 61.9-76.0) and a seroincidence rate of 15.9 birds per 100 bird-months at risk (95% CI 11.9-19.8). ND seroreversion rate was 6.2 birds per 100 bird-months at risk (95% CI 3.6-8.9). Regarding risk factors for ND, temporal variations occurred, and ND was more likely to be present in the Sudanian agro-ecological zone than in the Sahelian zone, in chickens than in other species, in flocks with higher numbers of Guinea fowl, and in flocks that had access to a waterbody. Control efforts would benefit from further increasing the ND vaccination coverage of village poultry, although this was already quite high (54.9%) for an African country. Seroconversion seemed satisfactory in vaccinated poultry, since 90.0% (95% CI 87.6-92.4) of these had ND antibodies. Further research should investigate the apparent lack of an epidemiologic role of domestic ducks for AI in Mali (unlike in Southeast Asia) and the potential role of Guinea fowl as a reservoir for ND.

International audience; Les maladies animales ainsi que les zoonoses, maladies infectieuses transmises entre les animaux et les hommes, sont un problème socioéconomique et de santé publique à l’échelle mondiale. Surveiller et contrôler ces maladies impliquent d’identifier les zones à risque. Des cartes de ces zones peuvent être établies en utilisant l’évaluation multicritère spatialisée, une méthode récente, rapide à mettre en œuvre et rigoureuse. Encore peu connue des décideurs en santé animale et publique vétérinaire, cette méthode est adaptée aux régions qui ont accès à peu de données épidémiologiques fiables, comme les pays du Sud à faible revenu ou les régions encore indemnes. Les cartes sont construites avec les experts locaux des régions concernées. Elles présentent des indices de risque qui combinent les données géographiques et environnementales, les avis d’experts et les informations issues d’études ou d’enquêtes existantes. Ces cartes peuvent ensuite être utilisées pour mieux cibler la surveillance et le contrôle des maladies.

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.

Wild terrestrial birds can act as potential local spreaders or bridge hosts for avian influenza viruses (AIVs) between waterfowl (the maintenance hosts of AIVs) and domestic avian populations in which AIVs may cause disease. Few studies have investigated this hypothesis, although it is an important knowledge gap in our understanding of AIV spread within socio-ecosystems. We designed a simple and reproducible approach in an agro-ecosystem in Zimbabwe based on: (1) bird counts at key target sites (i.e., wetlands, villages, intensive poultry production buildings and ostrich farms) to identify which wild birds species co-occur in these different sites and seasons when the risk of AIV transmission through these potential bridge hosts is maximal and (2) targeted sampling and testing for AIV infection in the identified potential bridge hosts. We found that 12 wild bird species represented the vast majority (79%) of co-occurrences in the different sites, whereas 230 bird species were recorded in this ecosystem. Specifically, three species - barn swallow, Hirundo rustica, red-billed quelea, Quelea quelea and cattle egret, Bubulcus ibis - represented the main potential bridge host species (65% of co-occurrences). In two out of these three species (i.e., barn swallow and red-billed quelea), we detected AIV infections, confirming that they can play a bridge function between waterfowl and domestic species in the ecosystem. Our approach can be easily implemented in other ecosystems to identify potential bridge hosts, and our results have implications in terms of surveillance, risk management and control of AIV spread in socio-ecosystems.

The term pandemic refers to an international or worldwide outbreak of an infectious disease which is limited in time. Due to their high infectiousness and easy person-to-person transmission, flu viruses repeatedly lead to pandemics (approx. 3 pandemics per century.). In contrast to an epidemic, a pandemic is not restricted to one area. The mortality of an influenza pandemic is greater than the seasonal flu wave, and is not restricted to the classical risk groups: high rates of infection can occur in all age groups, with peaks frequently occurring amongst young adults.The specific virological characteristics of the influenza virus represent a great challenge for the health system. In principle, any influenza virus which has never before - or at least not for a long time - circulated within the population can develop into a pandemic virus. One possible candidate amongst others appears to be the influenza virus A-H5N1. Influenza pandemics usually occur at intervals of 11 to 39 years, and 30 years have now passed since the last pandemic. At the moment, the national and international pandemic plans have in most cases not yet been completely worked out. The co-operation between the individual countries should be intensified, and in Germany in particular, efforts should be made - in view of the different concepts of the individual federal states - to arrive at a uniform action plan.The consequences of a pandemic affect both the economic and the social sphere. Hospitals, practicing doctors and public health services must jointly develop action plans in order to be able to care for large numbers of patients within a very short time. Occupational medical specialists should form a link between health services, companies and doctors and hospitals, and already be developing plans and their communication for the companies under their care.On entend par le terme pandémie l’irruption d’une maladie infectieuse limitée dans le temps et touchant plusieurs pays voire le monde entier. En raison de leur infectiosité importante et la contagion facilitée d’être humain à être humain, les virus de la grippe continuent souvent à entraîner des pandémies (env. 3 pandémies par siècle.). Contrairement à une épidémie, une pandémie n’est pas limitée localement. La mortalité en cas d’une pandémie d’influenza est plus importante que celle par une vague de grippe saisonnière et ne se limite pas aux seuls groupes à risques classiques : Des taux élevés d’infection peuvent survenir dans tous les groupes d’âge. Souvent, on trouve une pointe d’infection parmi les jeunes adultes.La caractéristique virologique spécifique du virus d’influenza constitue un grand défi pour le système de santé. En principe, chaque virus d’influenza qui n’a jamais circulé dans la population ou qui a cessé d’y circuler depuis longtemps pourrait se transformer en virus de pandémie. L’un des candidats possible, parmi d’autres, semble cependant être le virus d’influenza A-H5N1. Jusqu’à présent, les pandémies d’influenza survenaient à des intervalles de 11 à 39 ans, entretemps, plus de 30 ans sont passés depuis la dernière pandémie. À l’heure actuelle, la plupart des plans anti-pandémie nationaux et internationaux n’ont toujours pas été élaborés intégralement. Il convient que la coopération entre les différents états soit intensifiée et notamment en Allemagne il faudrait arriver à une solution uniforme, ceci notamment en vue des concepts variés des différents länder.Les conséquences d’une pandémie concernent à la fois le domaine économique et le domaine social. Les hôpitaux, les médecins travaillant en cabinet et les services de santé publique doivent mettre au point des plans des processus communs pour suivre un grand nombre de malades dans un laps de temps le plus court. Les médecins des entreprises devraient constituer une interface entre les services de santé, les entreprises et les médecins traitants ainsi que les hôpitaux et élaborer des concepts ainsi que la communication de ceux-ci pour les entreprises suivies par eux, à l’heure actuelle déjà.

Logistic regression models integrating disease presence/absence data are widely used to identify risk factors for a given disease. However, when data arise from imperfect surveillance systems, the interpretation of results is confusing since explanatory variables can be related either to the occurrence of the disease or to the efficiency of the surveillance system. As an alternative, we present spatial and non-spatial zero-inflated Poisson (ZIP) regressions for modelling the number of highly pathogenic avian influenza (HPAI) H5N1 outbreaks that were reported at subdistrict level in Thailand during the second epidemic wave (July 3rd 2004 to May 5th 2005). The spatial ZIP model fitted the data more effectively than its non-spatial version. This model clarified the role of the different variables: for example, results suggested that human population density was not associated with the disease occurrence but was rather associated with the number of reported outbreaks given disease occurrence. In addition, these models allowed estimating that 902 (95% CI 881–922) subdistricts suffered at least one HPAI H5N1 outbreak in Thailand although only 779 were reported to veterinary authorities, leading to a general surveillance sensitivity of 86.4% (95% CI 84.5–88.4). Finally, the outputs of the spatial ZIP model revealed the spatial distribution of the probability that a subdistrict could have been a false negative. The methodology presented here can easily be adapted to other animal health contexts.

Avian flu in the food chain. The reshape of the agro-industrial sector in Vietnam The crisis of avian influenza occurred in Vietnam in late 2003 has affected the organization of the local poultry value chain. This crisis has resulted in an alliance between the Vietnamese government and agro-industrial sector considered more capable than the traditional one, to meet the requirements of “ biosecurity”. In the short term, this alliance has allowed agro-industrial groups to develop and to take the control of a growing number of activities in the avian chain through a process of vertical integration (animal raising slaughtering, retailing) and, to a lesser extent, through contracting with farmers. This movement was slowed down once the crisis abated, since consumers turned back to traditional products, eliminating thus the less competitive groups. Thus, in the medium term, instead of benefiting the industrial sector at the expense of the traditional one, as one could expect, this crisis allowed a small number of agro-industrial groups, and especially international groups (we discuss in more detail the Asian group Charoen Pokphand) to establish their position in a market certainly promising, in the long term, despite its many hazards., La crise de la grippe aviaire survenue fin 2003 a fortement affecté l’organisation de la filière avicole vietnamienne. Cette crise s’est traduite par une alliance entre les pouvoirs publics vietnamiens et le secteur agro-industriel, ce dernier étant jugé plus apte que le secteur traditionnel à répondre aux impératifs de «biosécurité » . Sur le court terme, cette alliance a permis aux groupes agro-industriels de se développer et de prendre le contrôle d’un nombre croissant d’activités dans la filière avicole, par un processus de verticalisation (intégration d’activités de production, abattage, vente au détail) et dans une moindre mesure de contractualisation avec les éleveurs. Ce mouvement a cependant été freiné lorsque les consommateurs, une fois l’inquiétude passée, se sont de nouveau tournés vers des productions traditionnelles, contribuant à l’élimination des acteurs du secteur agro-industriel les moins compétitifs. Ainsi sur le moyen terme, plutôt que de favoriser le secteur industriel au détriment du secteur traditionnel comme on pouvait s’y attendre, cette situation a surtout favorisé une réorganisation interne à la filière industrielle : elle a permis à un petit nombre de groupes agro-industriels, et surtout aux groupes internationaux (en particulier le groupe asiatique Charoen Pokphand que nous examinons plus en détail) d’asseoir leur position sur un marché prometteur à long terme malgré ses nombreux aléas., Figuié Muriel, Tuan Pham Anh, Moustier Paule. Grippe aviaire dans la filière. La réorganisation du secteur agro-industriel au Vietnam. In: Revue d’études en Agriculture et Environnement, Vol. 94, N°4, 2013. pp. 397-419.

Highly pathogenic avian influenza virus subtype H5N1 is endemic in Asia, with live bird trade as a major disease transmission pathway. A cross-sectional survey was undertaken in northern Vietnam to investigate the structure of the live bird market (LBM) contact network and the implications for virus spread. Based on the movements of traders between LBMs, weighted and directed networks were constructed and used for social network analysis and individual-based modeling. Most LBMs were connected to one another, suggesting that the LBM network may support large-scale disease spread. Because of cross-border trade, it also may promote transboundary virus circulation. However, opportunities for disease control do exist. The implementation of thorough, daily disinfection of the market environment as well as of traders’ vehicles and equipment in only a small number of hubs can disconnect the network dramatically, preventing disease spread. These targeted interventions would be an effective alternative to the current policy of a complete ban of LBMs in some areas. Some LBMs that have been banned still are very active, and they likely have a substantial impact on disease dynamics, exhibiting the highest levels of susceptibility and infectiousness. The number of trader visits to markets, information that can be collected quickly and easily, may be used to identify LBMs suitable for implementing interventions. This would not require prior knowledge of the force of infection, for which laboratory-confirmed surveillance would be necessary. These findings are of particular relevance for policy development in resource-scarce settings.

The Highly Pathogenic Avian Influenza H5N1 (HPAI) virus is now considered endemic in several Asian countries. In Cambodia, the virus has been circulating in the poultry population since 2004, with a dramatic effect on farmers’ livelihoods and public health. In Thailand, surveillance and control are still important to prevent any new H5N1 incursion. Risk mapping can contribute effectively to disease surveillance and control systems, but is a very challenging task in the absence of reliable disease data. In this work, we used spatial multicriteria decision analysis (MCDA) to produce risk maps for HPAI H5N1 in poultry. We aimed to i) evaluate the performance of the MCDA approach to predict areas suitable for H5N1 based on a dataset from Thailand, comparing the predictive capacities of two sources of a priori knowledge (literature and experts), and ii) apply the best method to produce a risk map for H5N1 in poultry in Cambodia. Our results showed that the expert-based model had a very high predictive capacity in Thailand (AUC = 0.97). Applied in Cambodia, MCDA mapping made it possible to identify hotspots suitable for HPAI H5N1 in the Tonlé Sap watershed, around the cities of Battambang and Kampong Cham, and along the Vietnamese border.

Les infections des élevages de volaille par les virus de la grippe aviaire sont un fléau mondial. L’existence de virus aviaires pathogènes pour l’homme est connue depuis longtemps mais la survenue d’une épizootie à Hong Kong en 1997, accompagnée d’infections humaines mortelles a entraîné une prise de conscience et la mise en place de mesures pour le dépistage de ces infections, la caractérisation des souches en cause et la protection de la population au niveau mondial.Actuellement au moins trois souches d’Influenza A virus (H5N1), (H5N6), (H7N9) sont responsables de nombreux cas humains sévères. Si les deux premières sont panzootiques, la troisième reste cantonnée à la Chine. La lutte contre ces infections est difficile car elle nécessite des moyens financiers parfois hors de portée des pays touchés. Les conséquences économiques de ces épizooties sont importantes par les pertes de revenus des éleveurs, les arrêts de commercialisation d’animaux et de leurs sous-produits, la mévente dans le pays, les arrêts d’exportation. La fréquence de survenue des épisodes de grippe aviaires partout dans le monde, quel que soit le niveau de développement du pays montre qu’il est difficile de prévenir leur apparition, et que même l’application de mesures de lutte n’empêche pas le retour de ces infections, parfois plusieurs mois après un premier épisode apparemment résolu. La variabilité du génome des Influenzavirus peut faire craindre la survenue de mutations qui entraînerait une adaptation à l’homme et la survenue d’une pandémie par une souche pathogène contre laquelle la population n’aurait aucune défense.

International audience; Economic evaluations are critical for the assessment of the efficiency and sustainability of animal health surveillance systems and the improvement of their efficiency. Methods identifying and quantifying costs and benefits incurred by public and private actors of passive surveillance systems (i.e. actors of veterinary authorities and private actors who may report clinical signs) are needed. This study presents the evaluation of perceived costs and benefits of highly pathogenic avian influenza (HPAI) passive surveillance in Vietnam. Surveys based on participatory epidemiology methods were conducted in three provinces in Vietnam to collect data on costs and benefits resulting from the reporting of HPAI suspicions to veterinary authorities. A quantitative tool based on stated preference methods and participatory techniques was developed and applied to assess the non-monetary costs and benefits. The study showed that poultry farmers are facing several options regarding the management of HPAI suspicions, besides reporting the following: treatment, sale or destruction of animals. The option of reporting was associated with uncertain outcome and transaction costs. Besides, actors anticipated the release of health information to cause a drop of markets prices. This cost was relevant at all levels, including farmers, veterinary authorities and private actors of the upstream sector (feed, chicks and medicine supply). One benefit associated with passive surveillance was the intervention of public services to clean farms and the environment to limit the disease spread. Private actors of the poultry sector valued information on HPAI suspicions (perceived as a non-monetary benefit) which was mainly obtained from other private actors and media.

SRAS, grippes aviaires, virus Ébola, Mers-Cov... Depuis quelques dizaines d'années, les maladies infectieuses font l'objet d'une attention croissante de la part des scientifiques, des gestionnaires de risques, des médias et du public. Comment expliquer que les maladies infectieuses ne cessent d'émerger ? Et quels sont les défis que cette situation génère ? A travers cinq chapitres, des spécialistes analysent, depuis leurs différents domaines scientifiques, les dynamiques écologiques, sociales, institutionnelles et politiques associées aux maladies infectieuses émergentes. Mais plus qu'un éclairage pluridisciplinaire, cet ouvrage montre comment les concepts, les résultats scientifiques et les plans d'action des agences internationales ou gouvernementales se construisent et se répondent. Dans un langage clair et accessible, l'ouvrage explore les continuités mais aussi les réorganisations produites par la notion de maladie infectieuse émergente, tant dans l'activité collective que dans notre rapport au monde biologique. Il montre également les défis, mais aussi les opportunités dont se saisissent les acteurs qui y sont confrontés.

In ecology, the grouping of species into functional groups has played a valuable role in simplifying ecological complexity. In epidemiology, further clarifications of epidemiological functions are needed: while host roles may be defined, they are often used loosely, partly because of a lack of clarity on the relationships between a host’s function and its epidemiological role. Here we focus on the definition of bridge hosts and their epidemiological consequences. Bridge hosts provide a link through which pathogens can be transmitted from maintenance host populations or communities to receptive populations that people want to protect (i.e., target hosts). A bridge host should (1) be competent for the pathogen or able to mechanically transmit it; and (2) come into direct contact or share habitat with both maintenance and target populations. Demonstration of bridging requires an operational framework that integrates ecological and epidemiological approaches. We illustrate this framework using the example of the transmission of Avian Influenza Viruses across wild bird/poultry interfaces in Africa and discuss a range of other examples that demonstrate the usefulness of our definition for other multi-host systems. Bridge hosts can be particularly important for understanding and managing infectious disease dynamics in multi-host systems at wildlife/domestic/human interfaces, including emerging infections. Electronic supplementary material The online version of this article (doi:10.1186/s13567-015-0217-9) contains supplementary material, which is available to authorized users.

International audience; Newcastle disease (ND) and avian influenza (AI) are issues of interest to avian producers in Madagascar. Newcastle disease virus (NDV) is the major constraint for village aviculture, and avian influenza viruses type A (AIAV) are known to circulate in bird flocks. This study aims at classifying smallholder poultry farms, according to the combination of risk factors potentially associated with NDV and AIAV transmission and to assess the level of infection for each farm class. Two study sites, Lake Alaotra and Grand Antananarivo, were chosen with respect to their differences in terms of agro-ecological features and poultry productions. A typology survey involving 526 farms was performed to identify possible risk factors for (i) within-village, and (ii) between-village virus transmission. A cross-sectional serological study was also carried out in 270 farms to assess sero-prevalences of NDV and AIAV for each farm class and the link between them and risk factor patterns. For within-village transmission, four classes of farms were identified in Grand Antananarivo and five in Lake Alaotra. For between-village virus transmission, four classes of farms were identified for each site. In both sites, NOV sero-prevalence was higher than for AIAV. There was no evidence of the presence of H5 or H7 subtypes of AIAV. Sero-prevalences were significantly higher in Lake Alaotra than in Grand Antananarivo for both viruses (OR = 2.4, p = 0.02 for NDV, and OR = 9.6, p