Issues and special features of animal health research

In the rapidly changing context of research on animal health, INRA launched a collective discussion on the challenges facing the field, its distinguishing features, and synergies with biomedical research. As has been declared forcibly by the heads of WHO, FAO and OIE, the challenges facing animal health, beyond diseases transmissible to humans, are critically important and involve food security, agriculture economics, and the ensemble of economic activities associated with agriculture. There are in addition issues related to public health (zoonoses, xenobiotics, antimicrobial resistance), the environment, and animal welfare

Listeria monocytogenes translocates throughout the digestive tract in asymptomatic sheep

International audienceRuminants are fed forage which is often contaminated with Listeria, and frequently shed Listeria monocytogenes with their faeces. The present study was designed to localize the sites of infection in the digestive tract concomitant with Listeria faecal excretion in a sheep model. Ten Listeria-free sheep were inoculated per os with a dose of 10(10) c.f.u. of a pathogenic L. monocytogenes strain. Listeria received by two of the ten animals were radiolabelled with (111)indium oxine. The dissemination of the Listeria was assessed by in vivo imaging, by culture of bacteria in the faeces, organs and digesta samples taken at slaughter on days 1, 2, 6, 10 and 14 post-inoculation, and by measuring gamma radioactivity of samples on day 6. It was shown that Listeria spread through the entire volume of the forestomachs within 4 h, and through the whole gastrointestinal tract (GIT) within 24 h. Faecal shedding of Listeria lasted 10 days. Rumen, duodenum, jejunum, ileum, caecum and colon walls and digesta, mesenteric lymph nodes, liver and spleen were temporarily infected. However, Listeria persisted for at least 14 days in rumen digesta and retropharyngeal lymph nodes, and at a relatively high level (1 x 10(4) c.f.u. g(-1)) in palatine tonsils. These findings suggest that L. monocytogenes can translocate from all parts of the GIT, with the rumen digesta, but not the gallbladder, serving as a reservoir. The results indicate that brief and low-level faecal excretion of L. monocytogenes is concomitant with a transitory asymptomatic infection in sheep

A sociedade dos descartáveis

National audienc

INRA et maladies émergentes

National audienc

Spécificités de la santé animale en régions chaudes : le cas des maladies infectieuses majeures en Afrique

National audienceSpecific features of animal health in Africa are related to the diversity of climatic and environmental conditions, the predominance of low-input livestock farming systems, the intensity of long-distance animal movements (transhumance, trade), and difficult socio-economic conditions leading to poorly-funded veterinary services. Livestock farming systems and animal movements enhance the spreading of directly-transmitted diseases such as contagious bovine pleuropneumonia or peste des petits ruminants. Environmental conditions determine the biology of vectors (insects or ticks) and the spreading of vector-borne diseases. Some of them are specific to Africa, like human and animal trypanosomoses transmitted by tsetse flies. Others, like Rift Valley fever (RVF), transmitted by many mosquito species, are emerging. Should the RVF virus be introduced in favourable ecosystems (e.g., through livestock trade), RVF may install in other continents than Africa, like it has already been the case for the Arabic peninsula. The poor socio-economic conditions met in Africa make it more vulnerable than others to emerging or re-emerging animal diseases consecutive to climatic and environmental changes, increasing demography, and more intense travels and international trade. To obtain a substantial improvement of this situation, a regional disease-control strategy must be defined and implemented, with a continental and international coordination. This strategy should rely on integrated disease control with feed-back from national and regional disease surveillance networks, and more efficient tools and methods provided by research partners.Les spécificités de la santé animale en Afrique, exemple de zone à régions chaudes, tiennent à la fois aux caractéristiques climatiques et environnementales, aux systèmes d’élevage extensifs et à la mobilité animale (transhumance, commerce), ainsi qu’au contexte socio-économique difficile, avec des services vétérinaires disposant de moyens insuffisants. Les conditions d’élevage et la mobilité animale contribuent à la diffusion de maladies à transmission directe, comme la péripneumonie contagieuse bovine ou la peste des petits ruminants. L’environnement conditionne la biologie des vecteurs (insectes, tiques), donc la diffusion de maladies à transmission vectorielle. Certaines sont spécifiques à l’Afrique, comme les trypanosomoses humaines et animales. D’autres, comme la fièvre de la Vallée du Rift, dont le virus causal est transmis par de nombreuses espèces de moustiques, sont en pleine émergence. Elles sont susceptibles de coloniser d’autres écosystèmes via le commerce de bétail : ainsi cette maladie a été introduite sur la péninsule arabique et s’y est installée. La fragilité socio-économique de l’Afrique la rend plus vulnérable que les autres continents aux émergences de maladies animales, ensuite potentiellement exportables, liées aux changements climatiques et environnementaux, à l’accroissement démographique et à l’intensification des échanges internationaux et des voyages. L’amélioration de la situation sanitaire passe par la définition et la mise en œuvre au plan régional, avec une coordination continentale et internationale, d’une stratégie de lutte intégrée ; elle devrait s’appuyer sur des réseaux de surveillance et de recherche afin de mieux apprécier les évolutions épidémiologiques, et de disposer d’outils de diagnostic et de contrôle (vaccins, insecticides…) plus efficaces

Attentes et besoins exprimés par les acteurs des filières bovines pour la gestion de la santé des animaux

International audienceThe health disorders that may affect cattle in France can be divided into 3 groups of "diseases": D1- enzootic diseases of multifactorial or parasitic origin, D2- not regulated infectious diseases, D3- regulated diseases. Control measures (prevention, diagnosis, treatment), when they exist, are not always satisfactory. Anyway, they require the allocation of resources in research and development according to priorities to be established. Our aim was to collect the bovine industry stakeholders' opinion concerning expectations and needs to improve management of cattle health. We conducted in parallel 2 qualitative surveys, based on semi-structured interviews, one with farmers (n=143), and one with the other stakeholders in animal health (n=34). Needs for D1 (production diseases) dominated the concerns of the stakeholders (71 % of the farmers on average, up to 86 % for infertility; 49% of the other actors, up to 65 % for mastitis). Priorities differed logically according to the production systems: mastitis, neonatal diarrhoeas, and internal parasitism for dairymen, beef-cattle breeders, and breeder-fatteners, respectively. However, expectations were high in all the productions for some disorders (lameness). D2, and especially D3 worried the farmers less than the other actors. Blue tongue, in the forefront of the news at the time of the surveys, was quoted by all farmers and 71 % of the other actors. The farmers aimed primarily at means of better prevention, the other actors aimed more often at easier diagnosis. The need to improve farmers training was put forward by the other actors. Finally, criticisms were directed towards research organisations, particularly concerning the lack of interaction with the stakeholders in the field, or even at the lack of coordination between research organisations themselves. The results of this work will be submitted to an experts' committee, who will transform them into high-priority issues, to be proposed to the research organisations and funders.Les troubles de la santé susceptibles d’affecter le cheptel bovin en France peuvent être rangés en 3 groupes : M1- maladies enzootiques d'origine multifactorielle ou parasitaire (dites aussi maladies de production), M2- maladies infectieuses non réglementées, M3- maladies réglementées. Les mesures de maîtrise actuelles (prévention, diagnostic, traitement) ne donnent pas toujours satisfaction. Pour recueillir les attentes et besoins d’acteurs des filières bovines, 2 enquêtes qualitatives ont été réalisées par entretiens semi-directifs, auprès d’éleveurs (n=143), et d’autres acteurs en santé animale (n=34). Les besoins concernant M1 dominaient dans les préoccupations (71% des éleveurs, jusqu'à 86% pour l'infertilité ; 49% des autres acteurs, jusqu'à 65% pour les mammites). Les priorités différaient logiquement selon les systèmes de production : mammites, diarrhées néonatales, parasitisme interne, respectivement, pour les laitiers, les naisseurs, et les naisseurs-engraisseurs. Toutefois, les attentes sont fortes dans toutes les productions pour certains troubles (boiteries). Les M2, et surtout les M3, préoccupent moins les éleveurs que les autres acteurs à l’exception de la fièvre catarrhale ovine, d'actualité au moment des enquêtes. Les éleveurs visent en priorité les moyens de prévention, les autres acteurs sont souvent plus orientés vers le diagnostic. Le besoin d’améliorer la formation des éleveurs est mis en avant par les autres acteurs. Enfin, des critiques visent les organismes de recherche, dont l'absence d’échanges avec les acteurs de terrain, ou même le défaut de coordination entre organismes. Nos résultats de ce travail seront soumis à un comité d'experts pour les transformer en problématiques prioritaires, à proposer aux opérateurs de recherche et financeurs

Régime ensilage vs régime foin : infections mammaires et incidence économique en bovins laitiers

International audienc

Le référentiel maladies animales : de CERISA au Linked Data

National audienc

Eco-épidémiologie de Listeria monocytogenes en élevage caprin

National audienc

Repeated daily doses do not increase Listeria monocytogenes infection in ewes as shown by faecal excretion and serological monitoring

International audienceRuminants fed contaminated forage may shed Listeria monocytogenes in their faeces, and prolonged low daily doses of L. monocytogenes could cause listerial infection [Maijala, R., Lyytikainen, O., Autio, T., Aalto, T., Haavisto, L., Honkanen-Buzalski, T., 2001. Exposure of Listeria monocytogenes within an epidemic caused by butter in Finland. Int. J. Food Microbiol. 70, 97-1091. To compare listerial infection following single or repeated doses and the contamination of the environment with the excreted bacteria, ewes were orally inoculated with either 10(4), 10(6) or 10(10) cfu L. monocytogenes once, or daily for 10 days. Serological responses were monitored with indirect ELISAs using recombinant listeriolysin O (LLO), intemalin A (In1A) and internalin A-related protein (IrpA). The 24 inoculated animals displayed no symptoms, except for a transient hyperthermia in two animals given 10(10) cfu. One ewe died on day 9 after non-listerial mastitis followed by listerial septicaemia. L monocytogenes was recovered from day I post-inoculation until day 17 from the faeces of ewes inoculated with 106 or 1010 cfu. No antibodies were detected in ewes given 104 or 106 cfu. Anti-LLO and anti-IrpA antibodies were detected from day 15 in animals inoculated with 10(10) cfu, and this strengthened the conclusion that these long-lasting shedders were infected but asymptomatic carriers. An anti-InIA response was detected only at a very low level. These results suggest that repeated daily doses are no more effective than a single dose in causing infection in ewes. (C) 2006 Elsevier B.V. All rights reserved