Suchergebnisse

La politique de lutte antibovipestique au Tchad a connu différentes phases. Celles-ci se sont développées sur des durées suffisamment importantes pour valider éventuellement certains concepts comme celui de l'utilité de la vaccination périfocale sur des populations non vaccinées antérieurement. Après avoir examiné la fiabilité des données concernant le cheptel, les vaccinations et la pathologie, et rappelé les différents types de vaccins utilisés, on peut conclure que la vaccination périfocale, même accompagnée de la vaccination systématique des jeunes, n'a pas permis de contrôler la peste au Tchad. Seule la vaccination systématique du cheptel en permet le contrôle puis l'éradication. Un tableau résume les opérations de vaccination et les systèmes de suivi utilisés

Based on an analysis of the Meningitis Vaccine Project (MVP), a public-private partnership (PPP) set up to introduce the MenAfriVac® vaccine in African countries, this article examines the failures of an accelerated disease control programme that targeted a highly infectious disease. I argue that the integration of MenAfriVac® into the World Health Organization's (WHO) Expanded Programme on Immunisation had the effect of reinforcing inequalities in access, in particular during epidemic emergencies. I will also show how vaccine shortages during an outbreak in Niger led to political tensions and to the emergence of a parallel and unregulated 'black market' of vaccines.

Cette communication présente brièvement les résultats d'une évaluation technico-économique des actions de prophylaxie anti-infectieuse (vaccination anti-pestique et vaccination anti-pasteurellique) et anti-parasitaire (vermifugation) chez les petits ruminants. Elle a été réalisée au Sénégal sur cinq ans en milieu villageois et a impliqué 6500 petits ruminants dans le dispositif expérimental étendu du nord au sud du pays

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.

Vaccination of domestic poultry against avian influenza (AI) has been used on a large-scale in South East Asia since 2003 and in Egypt since 2006 to fight H5N1 highly-pathogenic avian influenza (HPAI) epidemics. The decision to use mass vaccination against HPAI in Egypt was taken as an emergency measure based on positive impact of such control measures in Vietnam and the People's Republic of China. However, three years on, the impact on disease control of AI vaccination in Egypt has been very limited. Despite the continuous vaccination of poultry against HPAI, poultry outbreaks and human cases are reported regularly. A recent assessment study highlighted substantial weaknesses in the current immunisation programme and its lack of positive impact on the spread of infection or the maintenance of public health safety. The shortcomings of the vaccination strategy may be attributed in part to a lack of sufficient support in terms of funding and communication, the absence of an efficient monitoring system, and inadequate training of field technicians. The difficulties of blanket vaccinations in semi-commercial farms and household poultry sectors are well known, however, improvements in the industrial sector should be possible though better government controls and greater collaboration with the private sector. AI vaccination should be regarded as just one control tool within a broader disease control program integrating surveillance, outbreak investigation, disease management systems, and the rigorous implementation of bio-security measures. If incorrectly implemented, AI vaccination has a limited impact as a disease control measure. Moreover, without strict bio-security precautions undertaken during its application, farm visits to vaccinate poultry could facilitate the spread of the virus and therefore become a risk factor with important implications on the maintenance of the virus and potential risk for human exposure.

En juillet 2008 apparaît pour la première fois au Maroc la peste des petits ruminants (PPR). S'agissant d'une maladie décrite comme des plus violentes et destructrices, son occurrence sur le territoire marocain intéressait une grande variété d'acteurs, des éleveurs aux décideurs en passant par les gouvernements étrangers et les organisations internationales. A partir d'une enquête qualitative menée au Maroc entre 2011 et 2012, l'article analyse d'abord la construction du problème de la PPR, puis montre comment, pour être efficaces, les recommandations de l'OIE ont été adaptées au contexte marocain. Parmi les différentes préconisations pour lutter contre la PPR, c'est la vaccination qui a été privilégiée à la fois par les acteurs nationaux et internationaux. L'article met en lumière les nombreux éléments, institutionnels ou contextuels, qui ont facilité le transfert de cette solution et de quelle manière le Maroc et ses services vétérinaires ont transformé ce défi en opportunité. Elle va légitimer et renforcer les choix de politique publique engagés par le Maroc avant la crise.

Background: Peste des petits ruminants (PPR) is a highly contagious and widespread viral infection of small ruminants (goats and sheep), causing heavy economic losses in many developing countries. Therefore, its progressive control and global eradication by 2030 was defined as a priority by international organizations addressing animal health. The control phase of the global strategy is based on mass vaccination of small ruminant populations in endemic regions or countries. It is estimated that a 70% post-vaccination immunity rate (PVIR) is needed in a given epidemiological unit to prevent PPR virus spread. However, implementing mass vaccination is difficult and costly in smallholder farming systems with scattered livestock and limited facilities. Regarding this, controlling PPR is a special challenge in sub-Saharan Africa. In this study, we focused on this region to assess the effect of several variables of PVIR in two contrasted smallholder farming systems. Methods: Using a seasonal matrix population model of PVIR, we estimated its decay in goats reared in sub-humid areas, and sheep reared in semi-arid areas, over a 4-year vaccination program. Assuming immunologically naive and PPR-free epidemiological unit, we assessed the ability of different vaccination scenarios to reach the 70% PVIR throughout the program. The tested scenarios differed in i) their overall schedule, ii) their delivery month and iii) their vaccination coverage. Results: In sheep reared in semi-arid areas, the vaccination month did affect the PVIR decay though it did not in goats in humid regions. In both cases, our study highlighted i) the importance of targeting the whole eligible population at least during the two first years of the vaccination program and ii) the importance of reaching a vaccination coverage as high as 80% of this population. This study confirmed the relevance of the vaccination schedules recommended by international organizations.

Le Burkina Faso est un pays sahélien enclavé dont l'économie repose principalement sur l'agriculture et l'élevage qui contribuent pour plus de 30 % à la formation du PIB et occupent plus de 80 % de la population active. L'élevage contribue pour plus de 10 % au PIB. La part des produits animaux, cuirs et peaux compris, dans la valeur des exportations est d'environ 26 % (en 1995) ; plaçant ainsi l'élevage au second rang des recettes d'exportations après le coton. Malgré cette contribution appréciable de l'élevage dans l'économie nationale, notre pays est importateur net de lait et de produits laitiers pour faire face à la demande intérieure. La valeur des importations s'est élevée en 1998 à 9 milliards F CFA. En dépit de ces importations massives la consommation actuelle est de 18 kg d'équivalent lait/habitant/an et est loin de la norme internationale qui est de 75 kg d'équivalent - lait/habitant/an. L'élevage traditionnel comprend 80 à 90 % du cheptel bovin et assure l'essentiel de la production laitière qui est saisonnière. Les fluctuations saisonnières ont une forte influence sur le prix de vente du litre de lait. Ainsi, il varie entre 100 F et 600 F CFA selon la localité et selon la saison. A long terme, le Gouvernement se fixe pour objectif de réduire de moitié le volume des importations de lait et de produits laitiers. Cette volonté politique se manifeste à travers, - l'élection, en juin 1997, du Ministère Délégué Chargé des Ressources Animales en Ministère plein, - L'adoption en novembre 1997, d'une Note d'Orientation de la Politique de développement du Secteur-Elevage au Burkina Faso; l'élaboration en cours du plan d'action du secteur élevage, - la création du Fonds de développement de l'élevage (FODEL); - la mise en oeuvre, avec l'appui de l'Union Européenne (7ème FED) du Programme National Pilote de Développement Laitier (PNPDL), - l'organisation en juin 1998, d'un atelier de réflexion sur la politique laitière au Burkina Faso sous l'égide du PNPDL. La présente communication fait l'économie des grandes conclusions de cet atelier et s'articule autour de deux points. - situation de la filière lait, - perspectives de développement de la filière lait.

Background: Biting midges of the genus Culicoides (Diptera: Ceratopogonidae) are small hematophagous insects responsible for the transmission of bluetongue virus, Schmallenberg virus and African horse sickness virus to wild and domestic ruminants and equids. Outbreaks of these viruses have caused economic damage within the European Union. The spatio-temporal distribution of biting midges is a key factor in identifying areas with the potential for disease spread. The aim of this study was to identify and map areas of neglectable adult activity for each month in an average year. Average monthly risk maps can be used as a tool when allocating resources for surveillance and control programs within Europe. Methods : We modelled the occurrence of C. imicola and the Obsoletus and Pulicaris ensembles using existing entomological surveillance data from Spain, France, Germany, Switzerland, Austria, Denmark, Sweden, Norway and Poland. The monthly probability of each vector species and ensembles being present in Europe based on climatic and environmental input variables was estimated with the machine learning technique Random Forest. Subsequently, the monthly probability was classified into three classes: Absence, Presence and Uncertain status. These three classes are useful for mapping areas of no risk, areas of high-risk targeted for animal movement restrictions, and areas with an uncertain status that need active entomological surveillance to determine whether or not vectors are present. Results: The distribution of Culicoides species ensembles were in agreement with their previously reported distribution in Europe. The Random Forest models were very accurate in predicting the probability of presence for C. imicola (mean AUC = 0.95), less accurate for the Obsoletus ensemble (mean AUC = 0.84), while the lowest accuracy was found for the Pulicaris ensemble (mean AUC = 0.71). The most important environmental variables in the models were related to temperature and precipitation for all three groups. Conclusions: The duration periods with low or null adult activity can be derived from the associated monthly distribution maps, and it was also possible to identify and map areas with uncertain predictions. In the absence of ongoing vector surveillance, these maps can be used by veterinary authorities to classify areas as likely vector-free or as likely risk areas from southern Spain to northern Sweden with acceptable precision. The maps can also focus costly entomological surveillance to seasons and areas where the predictions and vector-free status remain uncertain.

L'objectif de ce séminaire était de mettre en commun un certain nombre d'expériences de pays africains, méditerranéens et latino-américains ayant mis en oeuvre des programmes d'ajustement structurel, et de tirer de cette confrontation des conclusions sur la manière d'aborder le problème de l'ouverture des économies et sur son impact sur les différents secteurs productifs. Après une série d'étude de cas dans différents pays, la création de trois groupes de travail permettant d'approfondir certains thèmes de réflexion (rôle de l'Etat, dynamique de l'ajustement, besoins en informations pour l'évaluation ex ante de l'impact des PAS) est proposée. En annexe figurent les textes présentés lors de ce séminaire

West Africa is one of the regions the most concerned with structural food and nutrition security. Consequently, agricultural development pathways and scenarios are under high scientific and political scrutiny in this region. Rice, as a rapidly growing staple plays a key role in the West African diet representing close to 40% of the total volume of cereal consumed in the region. In the context of the 2008 food price crisis several West African countries have since proclaimed rice self-sufficiency as a target. Here, we show that rice yields tend to be, on average over the entire region, less stable (by a range of 15%–30%) than that of alternative crops, possibly substitutable in diets. The regions where yields of alternative crops are more stable than those of rice correspond to the main climatic regions where these crops are grown: sorghum, millet in the Sahelian and Sudanian regions and tubers in the Guinean region. Rice yields are significantly less stable for 33% of the comparisons considered and are significantly more stable than any alternative crop for 15% of the comparisons in few areas without clear longitudinal patterns. Models accounting for climate variability explain up to 17% of the variance of the data and reveal that yield variability differences between rice and alternative crops tends to widen in the areas where the monsoon precipitation is more variable between-years. The highest levels of variability of rice yields compared to alternative crops are recorded in regions where the monsoon varies strongly between years. Our analysis advocates for an explicit account of yield stability in West African rice expansion scenarios and supply strategies.

Aim To examine the different uses and perceptions of introduced Australian acacias (wattles; Acacia subgenus Phyllodineae) by rural households and communities. Location Eighteen landscape-scale case studies around the world, in Vietnam, India, Re´union, Madagascar, South Africa, Congo, Niger, Ethiopia, Israel, France, Portugal, Brazil, Chile, Dominican Republic and Hawai'i. Methods Qualitative comparison of case studies, based on questionnaire sent to network of acacia researchers. Information based on individual knowledge of local experts, published and unpublished sources. Results We propose a conceptual model to explain current uses and perceptions of introduced acacias. It highlights historically and geographically contingent processes, including economic development, environmental discourses, political context, and local or regional needs. Four main groupings of case studies were united by similar patterns: (1) poor communities benefiting from targeted agroforestry projects; (2) places where residents, generally poor, take advantage of a valuable resource already present in their landscape via plantation and/or invasion; (3) regions of small and mid-scale tree farmers participating in the forestry industry; and (4) a number of high-income communities dealing with the legacies of former or niche use of introduced acacia in a context of increased concern over biodiversity and ecosystem services. Main conclusions Economic conditions play a key role shaping acacia use. Poorer communities rely strongly on acacias (often in, or escaped from, formal plantations) for household needs and, sometimes, for income. Middle-income regions more typically host private farm investments in acacia woodlots for commercialization. Efforts at control of invasive acacias must take care to not adversely impact poor dependent communities.

Nous introduisons les concepts de forums hybrides (ou socio-technique), et décrivons la philosophie sous jacente et la mise en oeuvre d'une des composantes, c.a.d. une plateforme internet pour le partage de connaissances avec la société civile. Nous analysons les résultats après la première année d'opération. Le site http://sahel.info est un portail inspiré des forums en ligne populaires et est construit autour d'un gestionnaire de contenu gratuit appelé Coranto. En 2004 nous avons mis en ligne 124 éléments d'actualité sur les politiques, 1' économie, la recherche/universités, et les zones rurales du Sahel. Nous avons seulement enregistré le site sur le moteur de recherche Google et ne l'avons pas publicisé, et cependant il a été visité par plus de 1000 personnes différentes qui ont consulté 8500 pages (1000/mois) et voté 1200 fois au total (c.a.d. donné leur appréciation sur les articles). L'analyse des informations les plus (ou moins) consultées ou appréciées permet de cibler les thèmes d'intérêt pour les projets de recherche et de développement comme le DMP. Maintenant que la phase de prototypage est complétée nous allons pouvoir publiciser le site et attirer de nouveaux éditeurs. Le site http://dmp.sahel.info , basé sur la même plateforme que Sahel info, permet de partager les résultats et les informations spécifiques au DMP.

Unravelling the dynamics of land-use change is key to assess the environmental and socioeconomic impacts of land-based strategies regarding climate or energy. In this prospect, this paper proposes an analytical decomposition of land-use change resulting from a shock in agricultural demand which takes into account indirect effects from price signals. This analytical equation is numerically estimated using a global model of land-use combining biophysics and economics. While being relatively simple, this model captures the main processes of land-use change: change in the intensive and extensive margins, international trade, change in intermediary demand and possible by-products. At the global scale, our results show that yield losses due to the conversion of marginal land amount approximately to half of yield gains due to fertiliser use. At the regional scale, patterns of yield and area responses are depicted by assessing the potentials for intensification (yield gaps) and extensification (areas of extensive pastures) given the future pathways of agricultural demand.

Background: Biting midges of the genus Culicoides (Diptera: Ceratopogonidae) are vectors of bluetongue virus (BTV), African horse sickness virus and Schmallenberg virus (SBV). Outbreaks of both BTV and SBV have affected large parts of Europe. The spread of these diseases depends largely on vector distribution and abundance. The aim of this analysis was to identify and quantify major spatial patterns and temporal trends in the distribution and seasonal variation of observed Culicoides abundance in nine countries in Europe. Methods: We gathered existing Culicoides data from Spain, France, Germany, Switzerland, Austria, Denmark, Sweden, Norway and Poland. In total, 31,429 Culicoides trap collections were available from 904 ruminant farms across these countries between 2007 and 2013. Results: The Obsoletus ensemble was distributed widely in Europe and accounted for 83% of all 8,842,998 Culicoides specimens in the dataset, with the highest mean monthly abundance recorded in France, Germany and southern Norway. The Pulicaris ensemble accounted for only 12% of the specimens and had a relatively southerly and easterly spatial distribution compared to the Obsoletus ensemble. Culicoides imicola Kieffer was only found in Spain and the southernmost part of France. There was a clear spatial trend in the accumulated annual abundance from southern to northern Europe, with the Obsoletus ensemble steadily increasing from 4000 per year in southern Europe to 500,000 in Scandinavia. The Pulicaris ensemble showed a very different pattern, with an increase in the accumulated annual abundance from 1600 in Spain, peaking at 41,000 in northern Germany and then decreasing again toward northern latitudes. For the two species ensembles and C. imicola, the season began between January and April, with later start dates and increasingly shorter vector seasons at more northerly latitudes. Conclusion: We present the first maps of seasonal Culicoides abundance in large parts of Europe covering a gradient from southern Spain to northern Scandinavia. The identified temporal trends and spatial patterns are useful for planning the allocation of resources for international prevention and surveillance programmes in the European Union.