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Our survey aimed to investigate avian influenza (AI) and Newcastle disease (ND) prevalence and risk factors in three areas of Mali at risk for occurrence of H5N1 highly pathogenic avian influenza. Blood samples and cloacal and oropharyngeal swabs were collected from 1470 birds between February 2007 and May 2008 and were tested by commercial enzyme-linked immunosorbent assay to detect antibodies and real-time reverse-transcription (rRT)-PCR to detect virus. Risk factors associated with seropositivity or positive rRT-PCR were identified by random effect logistic regression. AI seroprevalence was significantly lower in birds from commercial farms (0%) than in village backyard birds (3.1%). For backyard birds, no individual risk factors (species, age, sex) were identified, but birds in the Mopti area in the Sahelian zone, where millions of wild birds migrate, were more seropositive than in the Sikasso area in the Sudano-Guinean zone (odds ratio [OR] ?=? 2.0, P ?=? 0.051). Among backyard birds nonvaccinated against ND, ND seroprevalence was 58.4%, and the odds of seropositivity was 2.0 higher in chickens than in ducks, 1.7 higher in females than in males, 3.1 higher in adults than in young birds, and 3.0 higher in poultry from the Sikasso area than from the Mopti area (P < 0.01 in all cases). Prevalence established by rRT-PCR was low for both AI virus (1.1%) and ND virus (2.6%) and was associated with no risk factors for AI but was higher in chickens than in ducks (OR ?=? 5.3, P ?=? 0.05) and in the Sikasso area than in the Mopti area (OR ?=? 3.4, P ?=? 0.027) for ND. For AI and ND, prevalence assessed by serology or rRT-PCR varied over time, although seasonal and interannual variation could not be clearly distinguished. The intracluster correlation coefficient for serologic data was low for AI (0.014) and higher for ND (0.222). These results are useful to optimize surveillance and control strategy for notifiable avian diseases in African countries with similar agroecological and resource-limited contexts.

International audience; Epidemiological surveys of avian influenza infections rarely focus on backyard poultry systems in remote locations because areas with low levels of poultry production are considered to have little influence on the emergence, re-emergence, persistence or spread of avian influenza viruses. In addition, routine disease investigations in remote areas often are neglected due to the lower availability and relatively high cost of veterinary services there. A bank of avian sera collected in 2005 from ethnic minority households in Ha Giang province (Northern Vietnam), located on the Chinese border, was analysed to estimate the seroprevalence of avian influenza virus (AIV) during a H5N1 epidemic and to identify potential risk factors for infection. The results suggest that the chicken population had been exposed to AIV with a seroprevalence rate of 7.2% [1.45; 10.5]. The H5 and H9 subtypes were identified with a seroprevalence of 3.25% [2.39; 4.11] and 1.12% [0.61; 1.63], respectively. The number of inhabitants in a village and the distance to the main national road were the most influential risk factors of AIV infection, and high-risk clusters were located along the road leading to China. These two results suggest a virus spread through commercial poultry exchanges and a possible introduction of AIV from southern China. Remote areas and small-scale farms may play an under-estimated role in the spread and persistence of AIV.

Determining if outbreak data collected by regional or international organizations can reflect patterns observed in more detailed data collected by national veterinary services is a necessary first step if global databases are to be used for making inference about determinants of disease maintenance and spread and for emergency planning and response. We compared two data sources that capture spatial and temporal information about H5N1 highly pathogenic avian influenza outbreaks reported since 2004 in four countries: Bangladesh, Egypt, Turkey, and Vietnam. One data source consisted of reports collected as part of each country's national veterinary services surveillance program, while the other data source included reports collected using the Emergency Prevention System for Priority Animal and Plant Pests and Diseases (EMPRES-i) global animal health information system. We computed Spearman rank-order correlation statistics to compare spatial and temporal outbreak distributions, and applied a space-time permutation test to check for consistency between the two data sources. Although EMPRES-i typically captured fewer outbreaks than detailed national reporting data, the overall similarity in space and time, particularly after 2006, reflect the ability of the EMPRES-i system to portray disease patterns comparable to those observed in national data sets. Specifically, we show that the two datasets exhibit higher positive correlations in outbreak timing and reported locations after 2006 when compared to December 2003 through 2006. Strengthening the capacity of global systems to acquire data from national and regional databases will improve global analysis efforts and increase the ability of such systems to rapidly alert countries and the international community of potential disease threats.

À partir d’une expérience ethnographique menée dans deux couvents français de carmélites, on a cherché à analyser les modalités concrètes de la vie claustrale. Sont examinés ici un cas limite d’utilisation de la parole, déclinée dans la spécificité de parole-silence, et la construction de familiarité qui se forme autour d’elle. On souhaite proposer une lecture phénoménologique du silence claustral, sur le plan de l’agi, de l’entendu et du parlé. Tout doit se réduire à l’essentiel, c’est-à-dire à l’élimination du superflu, qu’il s’agisse du matériel, del’émotionnel ou du linguistique. Listening, looking and staying quiet: dialogue in an enclosed community This is an analysis of the reality of enclosed life on the basis of an ethnographic study in two French Carmelite nunneries. The paper examines an extreme case of language use: the language of silence and the construction of familiarity which it creates. We propose a phenomenological reading of enclosed silence as it relates to actions, hearing and speaking. The ultimate aim is to reduce everything to the essential by eliminating the superfluous whether it be material, emotional orlinguistic.

SUMMARYIn developing countries, vaccination against highly pathogenic avian influenza subtype H5N1 (HPAI) in free-range poultry flocks is usually implemented as periodic campaigns and newborn chicks are generally not vaccinated by farmers between vaccination passes. The demographic population turnover leads to a continuous decrease in the population immunity rate (PIR) over time. We present a simple Leslie matrix model for estimating population turnover and PIR dynamics in a hypothetical small-size vaccinated free-range poultry population. Four different vaccination scenarios were identified assuming necessary procedures to achieve immunity. The results indicate that high levels of population immunity are difficult to sustain. Assuming an animal immunity response of 80% after vaccination and a constant population size, PIR 4 months after vaccination was ⩽30% in all the scenarios. Predictions averaged over time showed mean PIR between 36% and 48%, which is below the population immunity thresholds for eradication approximated from R0 estimates.

From December 2003 through January 2004, the Phnom Tamao Wildlife Rescue Centre, Cambodia, was affected by the highly pathogenic influenza virus (H5N1). Birds from 26 species died. Influenza virus subtype H5N1 was detected in 6 of 7 species tested. Cats from 5 of 7 species were probably infected; none died., published_or_final_version

The Virology Laboratory of the Central Laboratory of Animal Diseases in Ivory Coast at Bingerville received samples of wild and domestic avian species between February and December 2006. An RT-PCR technique was used to test for avian influenza (AI) and highly pathogenic AI subtype viruses. Among 2125 samples, 16 were type A positive; of which, 12 were later confirmed to be H5N1. Fifteen of these 16 type A positive samples were inoculated into the chorioallantoic cavity of 11-day-old embryonated hens' eggs for virus isolation. Eight produced virus with hemagglutination titres from 1/64 to 1/512. The 4/16 M-RT-PCR positive samples, which were H5N1 negative, were shown to be H7 subtype negative. The diagnostic efficiency of the laboratory for the surveillance of H5N1 in Ivory Coast was demonstrated. The positive cases of H5N1 were from a sparrowhawk (Accipter nisus); live market poultry and in free-range poultry, where the mortality rate was approximately 20% (2/10) and 96.7% (29/30) respectively. Currently, investigations into intensive poultry farms have proved negative for H5N1. No human cases have been reported this time.

Resume Les virus emergents ont defraye la chronique durant les annees 2003 et 2004. A cette occasion sont reapparues les peurs antiques concernant l’apparition d’un agent infectieux hautement pathogene, pouvant provoquer des epidemies associees a une mortalite elevee. Ces phenomenes sont clairement des menaces a repetition. L’analyse des mecanismes ayant permis l’apparition de ces virus montre que pour chaque virus emergent decrit, il ne s’agit en aucun cas de phenomenes purement aleatoires, mais bien de l’accumulation de facteurs qui permettent a ces agents infectieux de diffuser de l’animal vers l’homme. Differents modes d’infection existent, soit par transmission directe, soit par l’intermediaire des vecteurs (moustiques, tiques ou autres animaux). La conjonction de facteurs ecologiques, economiques et epidemiologiques font que ces epidemies naissent et eventuellement diffusent. Grâce au developpement des reseaux de surveillance et a l’amelioration des techniques diagnostiques, les virus responsables de ces epidemies sont mieux identifies. Les experiences recentes du SRAS et de la grippe aviaire en sont les meilleurs exemples.

We aimed at characterizing commercial and traditional village poultry farming in Mali, with a focus on practices influencing the risk of transmission of avian influenza and Newcastle disease. Surveys were conducted in 2009–2011 in a study area covering approximately 98% of the Malian poultry population. Among the 282 commercial farms investigated, of which 64 had not been known by the government authorities, 83% were located within a 50 km radius from the capitals of the country and regions and 54% had low biosecurity standard. Among the 152 randomly selected village household flocks investigated, characteristics were overall similar to those in other African countries but some differences were notable including a large flock size (median 44 poultry), a low presence of ducks and geese (11% and 1.1% of flocks, respectively), vaccination against Newcastle disease being common (49% of flocks), a low proportion of households selling sick and dead birds (0.7% and 0%, respectively) and limited cohabitation between poultry and humans at night. Our recommendations to limit the risk of disease transmission include (1) for commercial farms, to introduce compulsory farm registration and accreditation, to increase technical proficiency and access to credit for farms with low biosecurity, and to support poultry producer associations; (2) for village poultry, to promote better quarantine and management of sick and dead birds. Such detailed knowledge of country-specific characteristics of poultry production systems is essential to be able to develop more efficient disease risk management policies.

International audience; To date, infectious bronchitis virus (IBV) is potentially found in wild birds of different species. This work reports the survey of coronaviruses in wild birds from Madagascar based on the targeting of a conserved genome sequence among different groups of CoVs. Phylogenetic analyses revealed the presence of gammacoronaviruses in different species of Gruiformes, Passeriformes, Ciconiiformes, Anseriformes, and Charadriiformes. Furthermore, some sequences were related to various IBV strains. Aquatic and migratory birds may play an important role in the maintenance and spread of coronaviruses in nature, highlighting their possible contribution in the emergence of new coronavirus diseases in wild and domestic birds.

Since its first detection in Southern China in 1996, highly pathogenic avian influenza virus (HPAIV) H5N1 has emerged as a major global health threat and spread across three continents. In Africa, Mali was considered a country at high risk and surveillance of HPAIV H5N1 was complicated by the endemicity of another highly lethal poultry virus producing similar symptoms, Newcastle disease virus (NDV). The general aim of this thesis was to improve our understanding of the epidemiology of avian influenza (AI) and Newcastle disease (ND) in Mali and produce recommendations for improving the surveillance and control of these diseases. Prevalence/incidence studies showed: a low circulation of AI viruses (AIVs) -although higher in villages located in the inner delta of the Niger River where large populations of wild water birds migrate- and seemingly no particular epidemiological role of domestic ducks; a high circulation of NDV influenced by seasonal, geographic and flock (number of Guinea fowl, access to a pond) factors. Poultry production and trade studies revealed: a largely informal commercial poultry sector, mainly peri-urban and of low biosecurity level; characteristics of village poultry farming more (free-roaming, inadequate quarantine and sick/dead bird disposal) or less (high ND vaccination coverage, low palmipeds' density) favourable for AIVs and NDV transmission; mainly rudimentary low-biosecurity live poultry markets and a hierarchical structure of poultry trade network to/from the Sikasso district with four hubs identified based on network centrality measures. Evaluation of HPAI and ND surveillance found: a well-organised surveillance network but functioning only moderately satisfactorily, lack of targeting of active surveillance and largely insufficient sensitivity of passive surveillance. Specific strengths (laboratory diagnostic, information dissemination) were identified, as well as weaknesses some of which are easily correctable (data management, efficiency follow-up) while others require significant funding or commitment (resources for field work, involvement of private animal health professionals).

The Highly Pathogenic Avian Influenza virus H5N1 is still present in some of the poorest areas of the world as South-east Asia where the disease occurred on a regular basis in human and poultry. Early detection of the disease in poultry population is the most efficient method to avoid the spread of the virus to human. In poor rural communities of developing countries, such as Cambodia, this disease detection is often based on volunteer case reporting by farmers. However this surveillance method carries challenges when applied in difficult socioeconomic environments: low density of health facilities, poor communication systems, weak awareness of population, distrust on governmental authorities and lack of qualified staff. We have in this thesis conceived and applied new methods for the evaluation, the design or the improvement of passive surveillance in order to propose innovative methods to increase the involvement of rural communities in the reporting of zoonotic diseases.

La surveillance de la santé se définit comme la production et le traitement de données destinées à informer les programmes de mitigation des risques sanitaires. La surveillance des maladies infectieuses animales est généralement considérée comme un bien public, impliquant la responsabilité de l'Etat. La surveillance des maladies émergentes transfrontalières, dont l'influenza aviaire hautement pathogène (IAHP), est même perçue comme un bien public mondial, justifiant un partage d'informations entre Etats. La forme la plus répandue de la surveillance, dite passive ou réactive, repose sur la communication d'acteurs privés ou publics d'informations qu'ils détiennent sur l'état sanitaire des populations animales qu'ils observent aux autorités en charge de la surveillance. La surveillance se trouve donc confrontée à la problématique des biens publics dont la gestion est dépendante de la décision décentralisée d'acteurs privés. Deux questions se posent alors : quels sont les facteurs qui influencent la décision de transmettre une information aux systèmes de surveillance publics ? Ces facteurs sont-ils purement financiers ou impliquent-ils d'autres types d'enjeux, qui font intervenir l'environnement social de l'individu, le territoire dans lequel il s'insère et ses rapports de pouvoirs ? Une autre question est celle de l'existence de réseaux d'information, établis entre acteurs privés et publics permettant d'alerter un maximum d'acteurs de l'apparition d'un risque sanitaire. Comment ces réseaux de constituent-ils ? Dans quelle mesure sont-ils liés aux systèmes de surveillance publics ? Quelles formes de gestion du risque, sous contrôle privé ou public, permettent-ils ? Le cas étudié est celui de l'IAHP due à H5N1 chez les volailles domestiques en Asie du Sud-Est. Une étude a été menée dans quatre zones d'échelle spatiale réduite réparties sur les deux pays, trois au Viet Nam et une en Thaïlande. La théorie des graphs a été appliquée à la diffusion de l'information sur les suspicions d'IAHP entre acteurs privés et publics des territoires avicoles. La structure de ces réseaux d'information est conditionnée par l'organisation politique des territoires ruraux, sous forme de villages, et par les filières dans lesquels s'insèrent les élevages présents dans les territoires. Dans les zones d'étude du Viet Nam présentant un grand nombre d'élevage commerciaux privés, les acteurs amont de la filière avicole commerciale, qui fournissent aliments et produits vétérinaires aux éleveurs, ont un accès privilégié à l'information issue du secteur avicole commercial et villageois. Dans la zone d'étude de Thaïlande, les acteurs impliqués dans les combats de coqs ont un accès privilégié à l'information issue des éleveurs villageois. Ces acteurs centraux dans les réseaux facilitent la diffusion spatiale des informations et l'accès de l'ensemble des éleveurs à ces informations. Les autorités vétérinaires sont présentes dans les réseaux mais la priorité qui leur est accordée est faible en comparaison aux acteurs privés de la filière. En parallèle, des entretiens qualitatifs ou semi-quantitatifs utilisant les outils de l'épidémiologie participative ont été menés afin d'identifier les enjeux associés à la déclaration des suspicions aux autorités vétérinaire. Les enjeux diffèrent selon les territoires et les types de production avicoles qui les composent. Ces enjeux vont au-delà des problématiques purement financières : risques sanitaires et nuisances environnementales pour le voisinage, responsabilité dans les pertes économiques des autres éleveurs et des partenaires commerciaux, et valeur affective et sociale de l'animal sont autant de composantes potentielles de la décision de l'éleveur de déclarer une suspicion aux autorités. Une partie de ces enjeux est liée aux mesures de contrôle mise en place par l'Etat face au risque sanitaire. Cependant, d'autres sont strictement associés à la diffusion de l'information. C'est le cas, par exemple, des impacts des informations sur les prix du marché avicole. Par ailleurs quelques études pilotes montrent l'intérêt des outils basés sur des expériences de choix, en l'occurrence l'analyse conjointe, pour distinguer les enjeux perçus et ceux qui influent réellement la décision des acteurs. En complément des études à l'échelle locale, des enquêtes ont été menées avec des acteurs impliqués directement ou indirectement dans la surveillance à l'échelle nationale. L'efficacité de la surveillance passive est contrainte par la répartition des responsabilités administratives et financières entre Etats et gouvernements locaux. La mise sous tutelle des autorités vétérinaires par les gouvernements locaux au Viet Nam limite la remontée des informations aux autorités vétérinaires centrales. Les médias jouent un rôle dans la surveillance de l'IAHP. La relative liberté qui leur est accordée dans leurs investigations et leurs communications au public sur les risques liés à l'IAHP contraint les gouvernements locaux à exposer de manière plus transparente leur situation sanitaire. Les entreprises agro-alimentaires exercent une surveillance sanitaire privée sur les populations avicoles domestiques. Ce type de surveillance se substitue au système de surveillance publique.

International audience; Farmers may organize themselves to collectively manage risks such as animal diseases. Our study shows some evidence of such organization among fighting cock owners in Thailand. Fighting cocks were specifically targeted by HPAI (Highly Pathogenic Avian Influenza) H5N1 surveillance and control measures in Thailand because they were thought to pose a high risk of spreading diseases. In this work, we used a social-anthropological approach to gain an inside view of the issues associated with HPAI H5N1 surveillance in the cockfighting community in Thailand. Based on a qualitative analysis of data collected through in-depth interviews and observation of cockfighters’ practices, we found that fighting cock owners share a sense of belonging to the same community based on a common culture, values, interests, practices, and internal rules, including rules to manage poultry diseases. During the HPAI H5N1 outbreaks, these rules may have contributed to mitigating the potential risk associated with the intense movements of fighting cocks inside the country. Nevertheless, this community, despite the high awareness and know-how of its members regarding poultry diseases, has shown a strong reluctance to comply with HPAI surveillance programs. We suggest that this reluctance is due to important gaps between the logic and rationales underlying surveillance and those associated with cockfighting activities. Our study highlights the need for multi and trans-disciplinary research involving the social sciences to analyze interactions between stakeholders and the collective actions implemented by communities to face risks.

La peur de l'épidémie, du virus que l'on ne voit pas et qui vous fait succomber en moins de temps qu'il n'en faut pour le guérir est gravée dans un inconscient collectif empreint des réminiscences de peste noire et de grippe espagnole. Elle est à la fois une peur individuelle et collective, animale et atavique face à des maladies nouvelles qu'on ne sait pas guérir et qui frappent de manière imprévisible. A partir d'un corpus de dessins francophones et anglophones, cette contribution se propose de cerner les métaphores et les récurrences graphiques utilisées par les dessinateurs de presse à ce sujet. Elle se concentre tout particulièrement sur les déclinaisons imagées des peurs qu'ont générées en 2004 et 2009 puis 2014 les épidémies de grippe aviaire, de grippe porcine et du virus Ebola.

The avian influenza virus belongs to the influenza type A genus. Each strain can be sub-typed for its surface proteins : hemagglutinin (HA) and neuraminidase (NA). Aquatic birds represent the natural reservoir of the virus and occasionally transmit it to domestic poultry. The clinical form of the disease depends on the pathotype of the circulating strain. Most infections with low pathogenic (LP) strains are asymptomatic whereas those with highly pathogenic (HP) strains induce fowl plague. HP strains emerge from LP ones by mutations and insertions in the HA gene. Avian influenza can be occasionally transmitted to mammals including human. Evolution of recent HP H5N1 strains toward an increased pathogenicity and a wider host spectrum is worrying, and experts fear that these new strains could give rise to the next human influenza pandemic. Vaccination with inactivated or recombinant vaccines can be used in addition to biosafety measures to contend an outbreak., L’agent responsable des grippes aviaires est le virus influenza de type A. Chaque souche virale peut être sous-typée pour les deux protéines de surface : l’hémagglutinine (HA) et la neuraminidase (NA). Les oiseaux aquatiques constituent le réservoir de ces virus et peuvent occasionnellement les transmettre aux volailles domestiques. Les grippes aviaires se manifestent sous plusieurs formes cliniques selon le pathotype des souches virales circulantes. Les souches faiblement pathogènes (FP) n’induisent le plus souvent qu’une infection asymptomatique tandis que les souches hautement pathogènes (HP) sont responsables de peste aviaire. Les souches HP émergent des souches FP de sous-type H5 ou H7 par mutation et insertion dans le gène de l’HA. Les virus influenza aviaire peuvent être occasionnellement transmis à des mammifères, y compris l’homme. L’évolution des souches HP H5N1 asiatiques récentes vers un pouvoir pathogène accru et un spectre d’hôte élargi est inquiétant, et les experts redoutent que ces souches soient à l’origine d’une nouvelle pandémie humaine. La vaccination au moyen de vaccins inactivés ou recombinés peut être utilisée en complément des mesures de biosécurité pour lutter contre une épizootie., Bublot Michel. Les grippes aviaires, une menace permanente. In: Bulletin de l'Académie Vétérinaire de France tome 157 n°4, 2004. pp. 35-42.

Highly pathogenic avian influenza (HPAI) remains of concern as a major potential global threat. This article evaluates and discusses the level of vulnerability of medium and small-scale commercial poultry production systems in Thailand related to avian influenza virus re-emergence. We developed a survey on 173 farms in Nakhon Pathom province to identify the global level of vulnerability of farms, and to determine which type of farms appears to be more vulnerable. We used official regulations (the Good Agricultural Practices and Livestock Farm Standards regulations) as a reference to check whether these regulations are respected. The results show that numerous vulnerability factors subsist and could represent, in case of HPAI re-emergence, a significant risk for a large spread of the disease. Bio-security, farm management and agro-commercial practices are particularly significant on that matter: results show that these practices still need a thorough improvement on a majority of farms. Farms producing eggs (especially duck eggs) are more vulnerable than farms producing meat. Those results are consistent with the type of farms that were mostly affected during the 2004–2008 outbreaks in Thailand.

Highly pathogenic avian influenza (AI) due to H5N1 virus was first reported in Egypt in February 2006; since then, the government has allowed avian influenza vaccination in poultry. The present study evaluated the impact of AI vaccination in terms of cumulative annual flock immunity (CAFI): the percentage of bird × weeks protected by immunity. This evaluation took account of the combined effects of vaccination coverage, vaccine efficacy (VE), and different characteristics of household poultry production on the effectiveness of the adopted vaccination strategy (VS), and provided alternative options for improvement. The evaluation used a population and vaccination model that calculates the CAFI. Participatory approaches were employed in 21 villages to develop the vaccination and flock parameters required for the model. The adopted VS were compared in the model with three alternative VS scenarios in terms of the CAFI. Vaccination coverage varied among villages but was generally low (between 1 and 48 %; median 14 %). Under the adopted VS, the CAFI predicted for the villages ranged from 2 to 31 %. It was concluded that despite the enormous effort put into rural household poultry AI vaccination by the Egyptian government, village CAFI is unlikely to be maintained at the levels required to significantly reduce the virus load and restrict transmission. In HPAI-endemic countries that consider AI vaccination as one of the disease control options, the high cost of mass AI vaccination campaigns and their achievable benefits must be compared with other available control measures, which may include targeted vaccination. Achievable vaccination coverage, VE and the different characteristics of commercial and household (village) poultry production are key parameters determining the feasibility and cost-effectiveness of different AI vaccination strategies.

International audience; While the spatial pattern of the highly pathogenic avian influenza H5N1 virus has been studied throughout Southeast Asia, little is known on the spatial risk factors for avian influenza in Africa. In the present paper, we combined serological data from poultry and remotely sensed environmental factors in the Lake Alaotra region of Madagascar to explore for any association between avian influenza and landscape variables. Serological data from cross-sectional surveys carried out on poultry in 2008 and 2009 were examined together with a Landsat 7 satellite image analysed using supervised classification. The dominant landscape features in a 1-km buffer around farmhouses and distance to the closest water body were extracted. A total of 1,038 individual bird blood samples emanating from 241 flocks were analysed, and the association between avian influenza seroprevalence and these landcape variables was quantified using logistic regression models. No evidence of the presence of H5 or H7 avian influenza subtypes was found, suggesting that only low pathogenic avian influenza (LPAI) circulated. Three predominant land cover classes were identified around the poultry farms: grassland savannah, rice paddy fields and wetlands. A significant negative relationship was found between LPAI seroprevalence and distance to the closest body of water. We also found that LPAI seroprevalence was higher in farms characterised by predominant wetlands or rice landscapes than in those surrounded by dry savannah. Results from this study suggest that if highly pathogenic avian influenza H5N1 virus were introduced in Madagascar, the environmental conditions that prevail in Lake Alaotra region may allow the virus to spread and persist.

International audience; The surveillance of animal diseases has been the subject of numerous national and international initiatives further to the emergence, or re-emergence, of human diseases of animal origin. Noting that collaboration between stakeholders involved in surveillance was still insufficient, the international organisations have stressed the importance of harmonising data collection tools and mobilising stakeholders through participatory methods, education and communication. However, by focusing on technical constraints and individual motivations, these policies disregard the strategic role of information and potential conflicts of interest. Moreover, they ignore the practices of the many stakeholders in the field, who convey disease information within non-conventional surveillance networks. Hence the proposal to take these networks into account, without compromising the diversity of their objectives and operations, in order to make the surveillance of animal diseases more effective.; La surveillance des maladies animales a fait l'objet de nombreuses initiatives internationales et nationales suite à l'émergence, ou la réémergence, de maladies d'origine animale affectant l'homme. Constatant que les collaborations entre acteurs de la surveillance restaient insuffisantes, les organisations internationales ont mis l'accent sur l'harmonisation des outils de collecte, ainsi que sur la mobilisation des acteurs avec des méthodes participatives, l'éducation et la communication. Toutefois, en se focalisant sur les contraintes techniques et les motivations individuelles, ces politiques négligent le rôle stratégique de l'information et les conflits d'intérêt. De plus, elles ignorent les pratiques de nombreux acteurs de terrain, qui véhiculent une information sanitaire au sein de réseaux non conventionnels de surveillance. D'où la proposition de prendre en compte ces réseaux, sans gommer la diversité de leurs objectifs et de leur fonctionnement, afin d'améliorer l'efficacité de la surveillance des maladies animales.

National audience; The emergence and spread of Highly Pathogenic Avian Influenza H5N1 has caused substantial poultry-related economic losses and public health concerns in relation to a potential pandemic. While biosecurity measures for commercial poultry industry are of the highest standards, these measures are difficult to implement and often unaffordable for backyard poultry farming, particularly in tropical and low-income settings. We designed a feasible biosecurity intervention to improve flock hygiene in Cambodia, - based on community hygiene, cleaning of poultry flock areas and human and poultry movement control. We conducted a cluster randomized and controlled intervention trial in 18 villages in Takeo province to evaluate improvements in biosecurity-related knowledge and practices. The intervention relied on community involvement and community education using special information dissemination tools. We trained village teams (VT) to assist villagers in implementing the intervention using a cascade training approach, in which a few individuals were trained, who in turn trained a larger group of people. During the 14 month follow up, we conducted observational and interview-based surveys (baseline vs. final surveys, VT supervision visits, monitoring surveys) to assess VTs' motivation, intervention messages dissemination and the implementation of recommended measures. Most of villagers (95%, confidence interval: 87.8-100.0%) in intervention villages received general information about how to raise poultry. Farmers in intervention villages reported to have made more changes (≥1 biosecurity related practice during the study period) compared with that of control villages (70.0% (260/372) vs. 22.6% (85/377), p value

La politique commerciale du Sénégal s'intègre dans le système de régulation du commerce international par le biais de diverses organisations comme l'Organisation Mondiale du Commerce (OMC) et de l'Union Economique et Monétaire Ouest Africaine (UEMOA). Mais cette politique résulte aussi de dynamiques nationales ou locales. Dans les secteurs lait et viande de volaille, la politique commerciale a connu des évolutions, notamment au cours des grandes crises internationales de la fin des années 2000 (grippe aviaire, flambée des prix sur la marché mondial). Ainsi, plusieurs mesures ont été prises au niveau national comme la suspension des importations de viande de volaille en décembre 2005, et la suppression de la TVA et des Droits de Douane sur le lait en poudre en 2007. Toutefois, il n'a pas été clairement démontré si ces deux instruments de politique commerciale étaient liés à des objectifs sanitaires ou sociaux, ou à d'autres logiques. L'objet de cette thèse est d'analyser l'influence des logiques d'action dans l'élaboration, la mise en oeuvre et la remise en cause de ces deux instruments. Pour appréhender cet objet, l'approche instrumentale de l'action publique a été combinée à la sociologie des logiques d'action. La méthodologie était basée sur des allers retours entre la théorie et les données empiriques. Les deux instruments étudiés résultent de négociations entre les services étatiques, les acteurs économiques (Importateurs, industriels, éleveurs; etc.) et la société civile (interprofessions, organisations patronales et syndicales, associations de consommateurs, ONG). Ils découlent aussi de mouvements sociaux, d'idées véhiculées par la recherche en sciences économiques et sociales, de règles de fonctionnement de l'OMC et de l'UEMOA. De ce point de vue, l'analyse de ces instruments, dans une perspective diachronique, montre qu'ils résultent de la confrontation de quatre logiques d'action (institutionnelle, cognitive, stratégique et civique) inégalement réparties selon le type d'acteur. En définitive, l'analyse laisse apparaitre, une prédominance de la logique cognitive, une forte influence des logiques institutionnelle et stratégique et une faible influence de la logique civique.

Systems for animal disease mitigation involve both surveillance activities and interventions to control the disease. They are complex organizations that are described by partial or imprecise data, making it difficult to evaluate them or make decisions to improve them. A mathematical method, called loop analysis, can be used to model qualitatively the structure and the behavior of dynamic systems; it relies on the study of the sign of the interactions between the components of the system. This method, currently widely used by ecologists, has to our knowledge never been applied in the context of animal disease mitigation systems. The objective of the study was to assess whether loop analysis could be applied to this new context. We first developed a generic model that restricted the applicability of the method to event-based surveillance systems of endemic diseases, excluding the emergence and eradication phases. Then we chose the mitigation system of highly pathogenic avian influenza (HPAI) H5N1 in Cambodia as an example of such system to study the application of loop analysis to a real disease mitigation system., Breaking down the generic model, we constructed a 6-variables model to represent the HPAI H5N1 mitigation system in Cambodia. This construction work improved our understanding of this system, highlighting the link between surveillance and control which is unclear in traditional representations of this system. Then we analyzed the effect of the perturbations to this HPAI H5N1 mitigation system that we interpreted in terms of investment in a given compartment. This study suggested that increasing intervention at a local level can optimize the system's efficiency. Indeed, this perturbation both decreases surveillance and intervention costs and reduces the disease's occurrence., Loop analysis can be applied to disease mitigation systems. Its main strength is that it is easy to design, focusing on the signs of the interactions. It is a simple and flexible tool that could be used as a precursor to large-scale quantitative studies, to support reflection about disease mitigation systems structure and functioning.

The surveillance of animal diseases has been the subject of numerous national and international initiatives further to the emergence, or re-emergence, of human diseases of animal origin. Noting that collaboration between stakeholders involved in surveillance was still insufficient, the international organisations have stressed the importance of harmonising data collection tools and mobilising stakeholders through participatory methods, education and communication. However, by focusing on technical constraints and individual motivations, these policies disregard the strategic role of information and potential conflicts of interest. Moreover, they ignore the practices of the many stakeholders in the field, who convey disease information within non-conventional surveillance networks. Hence the proposal to take these networks into account, without compromising the diversity of their objectives and operations, in order to make the surveillance of animal diseases more effective.

Background Poultry represents an important sector in animal production, with backyard flocks representing a huge majority, especially in the developing countries. In these countries, villagers raise poultry to meet household food demands and as additional sources of incomes. Backyard production methods imply low biosecurity measures and high risk of infectious diseases, such as Newcastle disease or zoonosis such as Highly Pathogenic Avian Influenza (HPAI). We reviewed literature on biosecurity practices for prevention of infectious diseases, and published recommendations for backyard poultry and assessed evidence of their impact and feasibility, particularly in developing countries. Documents were sourced from the Food and Agriculture Organization (FAO) website, and from Pubmed and Google databases. Results A total of 62 peer-reviewed and non-referred documents were found, most of which were published recently (after 2004) and focused on HPAI/H5N1-related biosecurity measures (64%). Recommendations addressed measures for flock management, feed and water management, poultry trade and stock change, poultry health management and the risk to humans. Only one general guideline was found for backyard poultry-related biosecurity; the other documents were drawn up for specific developing settings and only engaged their authors (e.g. consultants). These national guidelines written by consultants generated recommendations regarding measures derived from the highest standards of commercial poultry production. Although biosecurity principles of isolation and containment are described in most documents, only a few documents were found on the impact of measures in family poultry settings and none gave any evidence of their feasibility and effectiveness for backyard poultry. Conclusions Given the persistent threat posed by HPAI/H5N1 to humans in developing countries, our findings highlight the importance of encouraging applied research toward identifying sustained and adapted biosecurity measures for smallholder poultry flocks in low-income countries.

ObjectiveEstimate the seroprevalence of influenza A virus in various commercial poultry farms and evaluate specific risk factors as well as analyze their genetic nature using molecular assays.Materials and methodsThis report summarizes the findings of a national survey realized from October 2010 to May 2011 on 800 flocks in 20 governorates. Serum samples were screened for the presence of specific influenza virus antibodies using cELISA test. Additionally, swab samples were tested by real time and conventional RT-PCR and compared with results obtained by others assays. Phylogenetic and genetic analyses of the glycoproteins were established for some strains.ResultsOut of the 800 chicken and turkey flocks tested by cELISA, 223 showed positive anti-NP antibodies (28.7%, 95% CI: 25.6-32.1). Significantly higher seroprevalence was found among the coastal areas compared to inland and during the autumn and winter. Broiler flocks showed significantly lower seroprevalence than layers and broiler breeders. The influenza virus infection prevalence increased after the laying phase among layer flocks. In addition, AIV seropositivity was significantly associated with low biosecurity measures. The Ag EIA and rRT-PCR tests revealed significantly higher numbers of AI positive samples as compared to cell cultures or egg inoculation. All new strains were subtyped as H9N2 by real time and conventional RT-PCR. Drift mutations, addition or deletion of glycosylation sites were likely to have occurred in the HA and NA glycoproteins of Tunisian strains resulting in multiple new amino acid substitutions. This fact may reflect different evolutionary pressures affecting these glycoproteins. The role of these newly detected substitutions should be tested.ConclusionOur findings highlight the potential risk of AIV to avian health. Strict enforcement of biosecurity measures and possible vaccination of all poultry flocks with continuous monitoring of poultry stations may ensure reduction of AIV prevalence and avoid emergence of more pathogenic strains.

We investigated the infl uence of a mass poultry vaccination campaign on passive surveillance of highly pathogenic avian infl uenza subtype (H5N1) outbreaks among poultry in Egypt. Passive reporting dropped during the campaign, although probability of infection remained unchanged. Future poultry vaccination campaigns should consider this negative impact on reporting for adapting surveillance strategies.

International audience; In 2006, the detection of the avian influenza (flu) H5N1 virus in Africa caused great concern: the virus could spread to the whole continent, and then be reintroduced to Europe by migratory birds. Epidemiological surveillance programmes were set up and national mechanisms strengthened with the support of international organisations. At the same time, research programmes were launched to describe and understand the virus transmission processes in Africa, and to assess the risks. Among these programmes, the GRIPAVI project is aimed at characterising the circulation of avian influenza viruses and Newcastle disease in both wild birds and domestic poultry. It shows that the African continent is not free from risk and that vigilance should continue. By specifying the virus persistence mechanisms in Africa and identifying risk situations, it proposes avenues for targeting surveillance and control strategies and thereby making them more efficient.; En 2006, la détection du virus de l'influenza (grippe) aviaire H5N1 en Afrique suscite une grande inquiétude : le virus pourrait se propager à l'ensemble du continent, puis être réintroduit en Europe par les oiseaux migrateurs. Des programmes de surveillance épidémiologique et de renforcement des dispositifs nationaux sont mis en place, appuyés par des organismes internationaux. En parallèle, des programmes de recherche sont lancés pour décrire et comprendre les processus de transmission de ce virus en Afrique, et évaluer les risques. Parmi eux, le projet Gripavi vise à caractériser la circulation des virus d'influenza aviaire et de la maladie de Newcastle à la fois dans l'avifaune sauvage et la volaille domestique. Il montre que le continent africain n'est pas exempt de risques et que la vigilance doit rester de mise. En précisant les modes de persistance du virus en Afrique et en identifiant des situations à risque, il met au jour des pistes pour cibler les stratégies de surveillance et de contrôle, et en améliorer ainsi l'efficacité.

International audience; The ability to attach to host cells is one of the main determinants of the host range of influenza A viruses. By using virus histochemistry, we investigate the pattern of virus attachment of both a human and an avian influenza virus in colon and trachea sections from 12 wild bird species. We show that significant variations exist, even between closely related avian species, which suggests that the ability of wild birds to serve as hosts for influenza viruses strongly varies among species. These results will prove valuable to assess the possibilities of interspecies transmission of influenza viruses in natural environments and better understand the ecology of influenza.

Avian influenza viruses (AIVs) are pathogens of global concern, but there has been little previous research on avian influenza in southern Africa and almost nothing is known about the dynamics of AIVs in the region. We counted, captured and sampled birds regularly at five sites, two in South Africa (Barberspan and Strandfontein) and one in each of Botswana (Lake Ngami), Mozambique (Lake Chuali) and Zimbabwe (Lakes Manyame and Chivero) between March 2007 and May 2009. The South African and Zimbabwean sites were visited every 2 months and the sites in Botswana and Mozambique every 4 months. During each visit we undertook 5-7 days of standardised bird counts followed by 5-10 days of capturing and sampling water-associated birds. We sampled 4,977 birds of 165 different species and completed 2,503 half-hour point counts. We found 125 positive rRT-PCR cases of avian influenza across all sites. Two viruses (H1N8 and H3N8) were isolated and additional H5, H6 and H7 strains were identified. We did not positively identify any highly pathogenic H5N1. Overall viral prevalence (2.51%) was similar to the lower range of European values, considerable spatial and temporal variation occurred in viral prevalence, and there was no detectable influence of the annual influx of Palearctic migrants. Although waterbirds appear to be the primary viral carriers, passerines may link wild birds and poultry. While influenza cycles are probably driven by the bird movements that result from rainfall patterns, the epidemiology of avian influenza in wild birds in the subregion is complex and there appears to be the possibility for viral transmission throughout the year.

Dans cet article, nous analysons dans quelle mesure la crise de la grippe aviaire survenue au Vietnam fin 2003 a affecté l'organisation de la filière avicole locale, et notamment la place des groupes agro-industriels dans cette filière. Sur la base d'enquêtes auprès de professionnels de la filière et de responsables politiques et d'une analyse de la presse économique, nous montrons que la crise s'est traduite par une alliance entre les pouvoirs publics vietnamiens et le secteur industriel, au détriment du secteur traditionnel, jugé peu apte à répondre aux impératifs de " biosécurité ". Le secteur privé s'est montré extrêmement actif pour relancer une filière dévastée et ceci malgré un contexte épidémiologique encore très incertain. Les groupes agro-industriels qui pouvaient encore produire ou importer des poussins de l'extérieur ont vite réinvesti la filière, prenant le contrôle d'un nombre croissant d'activités, 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 été porté par une demande des consommateurs inquiets d'une possible contamination alimentaire (portant non avérée). Mais, une fois la première crise passée, les consommateurs se sont de nouveau tournés vers des productions traditionnelles, freinant ainsi le processus d'industrialisation de la filière. Cependant, cette période a permis aux 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, qui malgré ses nombreux aléas, est sans aucun doute prometteur, compte tenu du boom de la consommation de viande dans les pays d'Asie.

Predicting areas of disease emergence when no epidemiological data is available is essential for the implementation of efficient surveillance programs. The Inner Niger Delta (IND) in Mali is a major African wetland where >1 million Palearctic and African waterbirds congregate. Waterbirds are the main reservoir of Avian Influenza Viruses (AIV). Our objective was to model their spatial distribution in order to predict where these viruses would be more likely to circulate. We developed a generalized linear model and a boosted regression trees (BRT) model based on total aerial bird counts taken in winter over six years. We used remotely sensed environmental variables with a high temporal resolution (10 days) to predict the spatial distribution of four waterbird groups. The predicted waterbird abundances were weighted with an epidemiological indicator based on the prevalence of low pathogenic AIV reported in the literature. The BRT model had the best predictive power and allowed prediction of the high variability of waterbird distribution. Years with low flood levels showed areas with a higher risk of circulation and had better spatial distribution predictions. Each year, the model identified a few areas with a higher risk of AIV circulation. This model can be applied every 10 days to evaluate the risk of AIV emergence in wild waterbirds. By taking into account the IND's ecological variability, it allows better targeting of areas considered for surveillance. This could enhance the control of emerging diseases at a local and regional scale, especially when resources available for surveillance programs are scarce. (Texte intégral)

En 2006, la détection du virus de l'influenza (grippe) aviaire H5N1 en Afrique suscite une grande inquiétude : le virus pourrait se propager à l'ensemble du continent, puis être réintroduit en Europe par les oiseaux migrateurs. Des programmes de surveillance épidémiologique et de renforcement des dispositifs nationaux sont mis en place, appuyés par des organismes internationaux. En parallèle, des programmes de recherche sont lancés pour décrire et comprendre les processus de transmission de ce virus en Afrique, et évaluer les risques. Parmi eux, le projet Gripavi vise à caractériser la circulation des virus d'influenza aviaire et de la maladie de Newcastle à la fois dans l'avifaune sauvage et la volaille domestique. Il montre que le continent africain n'est pas exempt de risques et que la vigilance doit rester de mise. En précisant les modes de persistance du virus en Afrique et en identifiant des situations à risque, il met au jour des pistes pour cibler les stratégies de surveillance et de contrôle, et en améliorer ainsi l'efficacité.

A case-control study at both village and farm levels was designed to investigate risk factors for highly pathogenic avian influenza H5N1 during the 2007 outbreaks in one province of Northern Vietnam. Data related to human and natural environments, and poultry production systems were collected for 19 case and 38 unmatched control villages and 19 pairs of matched farms. Our results confirmed the role of poultry movements and trading activities. In particular, our models found that higher number of broiler flocks in the village increased the risk (OR = 1.49, 95% CI: 1.12-1.96), as well as the village having at least one poultry trader (OR = 11.53, 95% CI: 1.34-98.86). To a lesser extent, in one of our two models, we also identified that increased density of ponds and streams, commonly used for waterfowl production, and greater number of duck flocks in the village also increased the risk. The higher percentage of households keeping poultry, as an indicator of households keeping backyard poultry in our study population, was a protective factor (OR = 0.95, 95% CI: 0.91-0.98). At the farm level, three risk factors at the 5% level of type I error were identified by univariate analysis: a greater total number of birds (P = 0.006), increase in the number of flocks having access to water (P = 0.027) and a greater number of broiler flocks in the farm (P = 0.049). Effect of vaccination implementation (date and doses) was difficult to investigate because of a poor recording system. Some protective or risk factors with limited effect may not have been identified owing to our limited sample size. Nevertheless, our results provide a better understanding of local transmission mechanisms of HPAI H5N1 in one province of the Red River Delta region in Vietnam and highlight the need to reduce at-risk trading and production practices.

International Conference on Animal Health Surveillance (ICAHS), Lyon, France, 17-20 May, 2011; International audience; For infectious diseases, as highly pathogenic avian influenza virus H5N1 (A/H5N1 HP), the need for an early detection and warning mechanism is essential, especially when countries have been free of disease for an extended period of time. Evaluating the sensitivity and the expected cost of surveillance are necessary steps to ensure an efficient and sustainable system. Stochastic scenario tree modeling has been used here to assess the sensitivity of the A/H5N1 HP surveillance system in sector IV of Thailand. The whole process of disease detection, from passive surveillance to X-Ray, has been described and sensitivity of each component and of the overall system has been estimated. Scenarios, according to selection of high risk areas, inclusion of components or sampling procedure, have been tested and discussed.

Sont examinés ici quelques-uns des problèmes posés par la représentation photographique de la catastrophe. Ils sont causés, principalement, par les limites du médium lui-même, qui ne peut enregistrer qu’un moment temporel distinct. Mais ils sont dus aussi au fait d’offrir au regard d’un spectateur heureusement éloigné – que ce soit dans le temps ou dans l’espace – la souffrance d’autrui. D’autres questions éthiques sont également soulevées par les simulacres de catastrophes, un phénomène récent dans les pratiques artistiques utilisant la photographie. Photograph the catastrophe This essay considers some of the problems posed by the photographic representation of catastrophe. These are to a considerable extent based on the limitations of the medium itself, which can only register a discrete moment in time. Other problems are raised by the “spectacle” of others’ suffering for the viewer, who is safely detached in time and space. Finally, there are ethical questions raised by the “simulation” of catastrophe, a recent phenomenon in art practices using photography.

Cet article est issu d’une enquête ethnographique réalisée à La Nouvelle-Orléans au début de l’année 2009 auprès d’un réseau d’acteurs et d’institutions rassemblés autour d’une cause commune : améliorer l’accès aux produits frais des habitants défavorisés, dans le cadre d’une politique de prévention de l’obésité soutenue par les pouvoirs publics. On y montre comment la catastrophe de Katrina est mobilisée par les acteurs réformateurs pour appuyer leur action. La reconstruction de la ville après le drame est considérée comme une opportunité pour changer les habitudes alimentaires et transformer les corps. En confrontant le récit de cette réforme de l’alimentation avec les expériences d’habitants aux prises avec des difficultés de subsistance, il s’agit d’interroger les transformations contemporaines de l’action publique : cette réforme, exprimant les problèmes d’alimentation dans un langage sanitaire et spatial, opérerait une double dénégation du social. Disaster as pretext for action Diet reform following Katrina The paper is based on an ethnographic study carried out in New Orleans. It concerns a grouping of actors and institutions dedicated to the common cause of improving the access to fresh products by poor people. This campaign was supported by the local authorities. It shows how reformers used the Katrina disaster to further their aims. The rebuilding of the city was used by these people as an opportunity to change eating habits and transform bodies. By contrasting the story of this reform of the diet with the experience of locals having to face subsistence problems we aim to reveal the contemporary transformations of public action. This reform thus expresses dietary problems in medical and spatial language thus operating a double denegation of the social.

Cet article retrace l’histoire d’un groupe d’experts qui ont lancé l’alerte sur les pandémies grippales à partir de la surveillance des oiseaux et des humains à Hong Kong. Il montre pourquoi ce lieu a pu servir de sentinelle pour les pandémies à venir, à partir de la perception d’une mutation catastrophique du virus grippal dans la population aviaire. Il suit les différentes crises à travers lesquelles l’alerte locale a pu donner lieu à une mobilisation globale, en impliquant des niveaux croissants d’autorité sanitaire. Il conclut sur la notion de frontières de la biosécurité, lieu à la fois biologique et social, naturel et politique, où des catastrophes apparaissent et où une temporalité dynamique s’ouvre à l’action collective. A sanitary look out post on the frontier of life Bird flu experts in Hong Kong The paper concerns a group of experts who sent out a warning of a flu pandemic based on their observation of birds and humans in Hong Kong. It shows why this place has served as a look out post for a new pandemic caused by a catastrophic mutation of the flu virus in an avian population. It traces the different crises which alerted the local population and which led to global mobilisation involving ever higher levels of medical authorities. The conclusion deals with the issue of the frontiers of biosecurity, a frontier that is at once biological, social, natural and political which reveals the appearance of catastrophes and where a temporal dynamic leads to collective action.

Le 2 mai 2008, le cyclone Nargis dévaste le delta birman. Dans une conjoncture que tendue, la catastrophe naturelle a pris la dimension d’une scène éminemment politique sur laquelle les différents intervenants, les instances internationales, les ong, le régime en place et le public, ont pu se situer autour de la question de l’aide humanitaire. En particulier, les classes moyennes de Rangoun, mobilisées le secours aux victimes du delta, y ont trouvé l’occasion d’exprimer leur condamnation des militaires au pouvoir et de la gestion gouvernementale de la crise. Selon l’interprétation populaire, Nargis est la sanction naturelle à un ordre politique contesté. The Nargis election The 2008 cyclone in Burma On the second of May 2008, the Nargis cyclone devastates the Burmese delta. In a tense political context the natural catastrophe takes on a highly political turn as different actors – ngos, the regime and public opinion – situate themselves in relation to the question of the place of humanitarian aid. In particular the Rangoon middle classes, much involved in aiding the victims, use the opportunity to voice their condemnation of the military men in power and of government action in dealing with the crisis. Popular opinion interprets Nargis as nature denouncing an unacceptable political system.

Une rumeur circule à la Guadeloupe : les Haïtiens arrosent avec de l’urine les produits maraîchers qu’ils vendent. Les clients guadeloupéens sont nombreux à se détourner de leurs étals. Cette rumeur accroît la confusion quant au choix des végétaux consommables alors que le pays traverse une crise sanitaire et alimentaire due à la contamination par le chlordécone. La virulence anti-haïtienne est forte et largement partagée. Toutefois, la familiarité des Haïtiens avec le vaudou les fait craindre, ce culte les rendrait forts en sorcellerie ; aussi la plupart des Guadeloupéens évitent-ils les conflits personnels avec un Haïtien. L’auteur, en s’appuyant sur les travaux en anthropologie à propos de la parole ainsi que sur ceux des sociologues qui ont étudié la rumeur, montre que relayer une rumeur est l’acte de parole le plus économique pour stigmatiser les membres d’une communauté qu’on peut, par ailleurs, redouter. Rumour in Guadeloupe Of certain suppose practices of the Haitians There is a rumour in Guadeloupe that Haitians sprinkle the vegetable products they sell with urine. As a result many Guadeloupian buyers avoid their stalls. This rumour increases confusion about which vegetables can be eaten at a time when the country is suffering from a health crisis caused by chlordecone contamination. Anti-Haitian feeling is strong and widespread. However, Haitians familiarity with Woodou means that they are feared as it is believed this makes them experts in sorcery and, as a result, conflict with them is avoided. The author bases herself on linguistic anthropology and the sociology of rumour and she shows how speech is the most economic act that can be used to stigmatise a feared group.