Debris flow hazards due to land use change above source areas in torrent catchments. The case study of Les Arcs (Savoie, France)

For a few decades, land use has changed due to developments in mountainous regions and this has resulted in new pressures on the environment. Consequently, slope instabilities could be a physical expression of such imbalance. Since the 1960s, debris flows events have occurred with an increasing frequency on Les Arcs catchment as it never happened before. At the same time, a large skiing area has been expending on the upper slopes. The study of climatic series shows that rainfall events linked to debris flow triggering were not especially intense compared to the more extreme precipitations recorded in the area for the past middle century. This observation suggests that additional factors have taken part in the debris flow triggering for the last fifty years. Following this logic, the space-time study of land use has underlined the role of winter sport resort expansion on processes such as runoff and erosion affecting torrent banks and beds, directly at the origin of debris flow generation. A complementary analysis of effects on hydrology, supported by a hydrological modelling (PCRaster Software) has been carried out as well. According to modelling results, the land use conversion is responsible for a change of annual water balance resulting in a significant increase of torrent water flow. Particularly, these effects are emphasised by the localization of converted surfaces (roads, buildings, car parks, ski runs, sport facilities...) in the catchment recharge areas above steep slopes of torrent channels, where materials are liable to be mobilized. Indeed at this interface, during rainfall events the water flow and especially the peak flow are more intense than in the past, due to water rerouting and concentrating that may activate erosive processes above debris flow source areas. At the catchment scale, the increasing number of debris flow events seems to be the answer to this change

Avian influenza vaccine development, practical application in developing countries

Vaccination is a useful tool for the control of avian influenza (AI) outbreaks, but its use is forbidden in most countries worldwide because of its interference with AI screening tests and its negative impact on poultry trade. Currently licensed AI vaccines increase host resistance to the disease but have a limited impact on the virus transmission. To control or eradicate the disease, a carefully conceived vaccination strategy must be accompanied by strict bio-security measures. Some countries have, in the past, authorised vaccination under special circumstances with contrasting results, from control and disease eradication (USA, Italy) to endemism and antigenic drift of the viral strain (Mexico, Pakistan). Extensive vaccination programs are ongoing in Vietnam People's Republic of China and Indonesia to control the H5N1 epidemic. This paper provide practical information on the available AI vaccines and associated diagnostic tests, the vaccination strategies applied in Asia and their impact on the disease epidemiology

Avian influenza vaccines: a practical review in relation to their application in the field with a focus on the Asian experience

Vaccination can be a useful tool for the control of avian influenza (AI) outbreaks, but its use is prohibited in most of the countries worldwide because of its interference with AI surveillance tests and its negative impact on poultry trade. AI vaccines currently in use in the field increase host resistance to the disease but have a limited impact on the virus transmission. To control or eradicate the disease, a carefully conceived vaccination strategy must be accompanied by strict biosecurity measures. Some countries have authorized vaccination under special circumstances with contradictory results, from control and disease eradication (Italy) to endemicity and antigenic drift of the viral strain (Mexico). Extensive vaccination programmes are ongoing in South East Asia to control the H5N1 epidemic. This review provides practical information on the available AI vaccines and associated diagnostic tests, the vaccination strategies applied in Asia and their impact on the disease epidemiology. (Résumé d'auteur

Collaborations sino-européennes en santé animale : le projet LinkTADs et autres activités menées par le Cirad

La Chine est aujourd'hui le premier producteur mondial de produits animaux et la surveillance des maladies animales et zoonotiques y est donc un enjeu mondial. Afin de renforcer les collaborations avec la Chine dans ce domaine, une action de coordination a été lancée par l'Union européenne, le projet LinkTADs. Ce projet, coordonné par la FAO, a d'ores et déjà permis d'identifier les principaux besoins de recherche sur des maladies jugées prioritaires par les partenaires chinois et européens. Ce projet a été construit sur des collaborations développées depuis dix ans entre la Chine et l'Europe, notamment celles portées par le Cirad en Chine et en Asie du Sud-Est. L'objectif à moyen terme est de faciliter l'insertion des partenaires chinois dans une logique de réseau et de projets de recherche régionaux et internationaux et de renforcer ainsi la gestion des maladies animales et zoonotiques transfrontalières. (Résumé d'auteur

Advocacy for identifying certain animal diseases as “neglected”

According to the World Health Organization (WHO), neglected tropical diseases (NTDs) affect almost 1,000,000,000 people in 149 countries (http://www.who.int/neglected_diseases/diseases/en/). Most are small family farmers living in the least-developed countries where health systems are often inadequate, and climate conditions are favourable to infectious and parasitic diseases. These diseases hinder socioeconomic development, maintain poverty, and impede the achievement of UN sustainable development goals (SDGs) [1]. Economic analyses have shown that their control, elimination, or eradication would lead to net economic benefits [2]. Rapid progress can be achieved when organised health systems, whether public, private, or mixed, are in place to provide diagnostic methods and facilities, treatments, and vaccines. Of the 18 diseases on WHO's list of NTDs, only 5 are zoonoses: Taenia solium cysticercosis, echinococcosis, leishmaniasis, rabies, and human African trypanosomiasis (HAT). Some authors consider this list incomplete and believe that at least 3 other major zoonoses—anthrax, bovine tuberculosis, and brucellosis—should be included [3]. Moreover, while some public–private partnerships—e.g., the Global Alliance for Livestock Veterinary Medicines, GALVmed (https://www.galvmed.org/)—now target major livestock diseases impacting smallholders by connecting academia, public research institutes, and the pharmaceutical sector, no strictly animal disease (i.e., nonzoonotic) has been labelled “neglected”. Nevertheless, animal diseases directly impact people's livelihoods. Furthermore, due to the multiple functions fulfilled by livestock in rural societies—as sources of food, income, and social status—animal diseases ultimately also impact human health. (Résumé d'auteur

Influenza aviaire au Vietnam : état des lieux et complémentarité des activités de surveillance et des études épidémiologiques (2007–2011)

L'apparition de l'influenza aviaire hautement pathogène (IAHP) H5N1 en 2003 a accentué la nécessité de disposer de systèmes de surveillance en santé animale efficaces pour éviter une pandémie grippale. Dans certains pays des mesures ad hoc ont été mises en place, soutenues par des bailleurs mais sans véritable ancrage sur le terrain ou auprès des institutions publiques chargées d'assurer une veille sanitaire. D'autres dispositifs, au contraire, ont permis de renforcer les structures déjà en place. L'objectif de cette étude a été de faire un état des lieux des dispositifs de surveillance de l'IAHP chez les volailles au Vietnam afin d'évaluer la complémentarité des dispositifs nationaux (financés par le gouvernement vietnamien) et des programmes mis en place par les bailleurs internationaux. Les différents types de dispositifs de surveillance, d'études épidémiologique et de projets recherche sur l'IAHP au Vietnam ont été évalués dans l'ensemble complémentaires, assurant une couverture homogène du pays. Cependant les nouvelles politiques gouvernementales ont pour la plupart été décidées sans évaluation des actions antérieures en raison d'une insuffisance de données d'évaluation ou d'impact des projets mis en oeuvre. Un dysfonctionnement du système de surveillance passive, avec un retour limité des résultats et des recommandations aux agents de terrain, a également été constaté. La mise en place de dispositifs de surveillance active efficients en complément de la surveillance passive s'avère donc essentielle dans la gestion du risque de l'IAHP au Vietnam. (Résumé d'auteur