Epidemic disease risks and implications for Veterinary Services.

Growth in the livestock sector is associated with heightened risk for epidemic diseases. The increasing spillover of new diseases from wildlife is being driven by wide-scale anthropogenic changes allowing for more frequent and closer wildlife-human and wildlife-livestock contacts. An increasing number of epidemics in livestock are associated with rapid transition of livestock systems from extensive to intensive, and local to global movement of livestock and their products through value chain networks with weak biosecurity. Major livestock epidemics in the past two decades have had substantial economic impacts, and the COVID-19 pandemic highlights the devastating socio-economic consequences that spillovers can have when not identified and controlled early in the process of emergence. This highlights the importance of Veterinary Services to integrated, whole-of-society efforts to control infectious diseases in animals. Emphasis within Veterinary Services must be placed on prevention and preparedness. The authors suggest four areas for continued improvement in Veterinary Services to meet this challenge. These are a) continued development of staff capacity for risk assessment and value chain analysis, together with improved policies and communication, b) appropriate adaptation of approaches to prevention and control in resource-poor settings, c) improved multi-sectoral and transboundary cooperation, which enables the sharing of resources and expertise, and d) systematic approaches that enable Veterinary Services to influence decisionmaking for trade, markets, business, public health, and livelihood development at the national and regional levels.

La croissance du secteur de l'élevage est associée à un risque accru de maladies épidémiques. Les changements anthropiques à grande échelle sont à l'origine du nombre croissant de maladies émergentes atteignant de nouvelles espèces réceptives (spillover) à partir de réservoirs sauvages, à la faveur de contacts plus fréquents et plus rapprochés entre la faune sauvage et les humains, d'une part, et entre la faune sauvage et les animaux domestiques, d'autre part. On considère qu'un nombre croissant d'épidémies affectant le bétail sont dues à la transition rapide des systèmes d'élevage extensif vers des systèmes intensifs, et aux mouvements du bétail et des produits de l'élevage de l'échelle locale à l'échelle mondiale par le biais de réseaux de chaînes de valeur dotés d'un faible niveau de biosécurité. Au cours des deux dernières décennies, d'importantes épidémies affectant le bétail ont eu un impact économique considérable ; en outre, la pandémie de COVID-19 a mis en évidence les conséquences socio-économiques dévastatrices des atteintes de nouvelles espèces réceptives par des agents pathogènes, lorsque ces maladies ne sont pas détectées et maîtrisées dès le processus d'émergence. Cela souligne l'importance cruciale des Services vétérinaires dans les efforts de lutte contre les maladies infectieuses chez les animaux, qui doivent être intégrés et mobiliser la société entière. Les Services vétérinaires doivent mettre un accent particulier sur la prévention et la préparation. Les auteurs proposent quatre aspects d'amélioration continue pour que les Services vétérinaires puissent relever ce défi. Il s'agit : a) du développement permanent des compétences des personnels vétérinaires en matière d'évaluation du risque et d'analyse des chaînes de valeur, et leur articulation avec de meilleures politiques et une communication plus performante ; b) une adaptation adéquate des méthodes de prévention et de contrôle dans les configurations faiblement dotées en ressources ; c) une meilleure coopération multisectorielle et transfrontalière afin de partager les ressources et les compétences ; d) des dispositifs systémiques permettant aux Services vétérinaires d'influencer les prises de décision en matière d'échanges internationaux, de marchés, de commerce, de santé publique et de développement des moyens de subsistance, à l'échelle nationale et régionale.

El crecimiento del sector pecuario está condicionado por la existencia de un mayor riesgo de enfermedades epidémicas. La creciente diseminación de nuevas enfermedades a partir de animales silvestres es consecuencia de transformaciones antrópicas a gran escala que posibilitan un contacto más frecuente y estrecho de la fauna silvestre con el ser humano y el ganado. Cada vez son más las epidemias del ganado que tienen que ver con la rápida transición de los sistemas pecuarios de un régimen de producción extensiva a otro de producción intensiva y con el paso de la dimensión local a la mundial de la circulación de animales y sus derivados a través de redes de cadenas de valor que presentan una endeble seguridad biológica. En los últimos dos decenios ha habido grandes epidemias que han afectado al ganado y tenido importantes consecuencias económicas. La pandemia de COVID-19 es un elocuente ejemplo de los devastadores efectos socioeconómicos que puede tener la extensión de un patógeno cuando no se detecta y controla en un momento lo bastante precoz del proceso de emergencia. Ello pone de relieve la importancia que revisten los Servicios Veterinarios para que toda la sociedad pueda reaccionar de forma integrada a la hora de combatir las enfermedades infecciosas de los animales. Dentro de los Servicios Veterinarios, conviene poner el acento en la prevención y la preparación. Para lograr este objetivo los autores señalan cuatro ámbitos que exigen una constante mejora: a) el desarrollo continuo de la capacidad del personal en materia de determinación de riesgos y análisis de cadenas de valor, ligado a la mejora de las políticas y la comunicación; b) la adecuada adaptación de los métodos de prevención y control en contextos de escasos recursos; c) una mejor cooperación multisectorial y transfronteriza, que permita poner en común recursos y competencias técnicas; y d) enfoques sistemáticos que hagan posible que los Servicios Veterinarios influyan en los procesos decisorios relativos al desarrollo del comercio, los mercados, las empresas, la salud pública y los medios de sustento a escala tanto nacional como regional.

Wildlife conservation status and disease trends: ten years of reports to the Worldwide Monitoring System for Wild Animal Diseases.

Disease is an increasingly recognised threat to wild animal populations and the conservation of endangered species. The World Organisation for Animal Health (OIE) Worldwide Monitoring System for Wild Animal Diseases (WAHIS-Wild) serves as the main global information portal for wildlife disease events, compiled via voluntary reporting by countries on non-OIE-listed diseases. The first decade of reports to WAHIS-Wild were analysed to identify trends and examine their relevance for conservation. Between 2008 and 2018, a total of 4,229 wildlife disease events were reported, with the majority from the European continent. When standardised for nomenclature changes, 54 unique previous or current non-OIE-listed diseases were reported. The most common disease events (collectively representing > 50% of reports) were chemical poisoning (12.5% of events reported), infection with low pathogenic avian influenza viruses (11.9%), infection with Salmonella enterica (10.8%), infection with Pasteurella spp. (8.4%) and infection with Trichomonas spp. in birds and reptiles (7.5%). Reports indicated disease in 501 unique species, 19.2% of which are listed as endangered species based on the International Union for Conservation of Nature (IUCN) Red List of Threatened Species, and 30.7% of which are protected under the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). The findings suggest reporting gaps, including likely geographical area and other biases. More systematic reporting of wildlife disease and use of this information in biodiversity assessment and decision-making would result in better animal health and conservation coordination in a One Health context.

Les maladies constituent une menace dont l'importance sur les populations d'animaux sauvages et la conservation des espèces menacées est de plus en plus reconnue. Le Système mondial de suivi des maladies des animaux sauvages (WAHIS-Wild) de l'Organisation mondiale de la santé animale (OIE) est le principal portail mondial d'information sur les événements sanitaires affectant la faune sauvage. Il s'appuie sur les informations notifiées de manière volontaire par les pays concernant les maladies non listées par l'OIE. Les auteurs présentent les résultats d'une analyse des rapports notifiés à WAHIS-Wild au cours de ses dix premières années d'existence réalisée dans le but de relever les tendances et d'examiner leur pertinence pour la conservation de la faune. Entre 2008 et 2018, au total 4 229 événements sanitaires affectant la faune sauvage ont été notifiés, dont la majorité par des pays européens. Une fois normalisées pour tenir compte de la nouvelle nomenclature, les notifications couvraient 54 maladies individuelles anciennes ou actuelles non listées par l'OIE. Les événements sanitaires les plus fréquents (représentant collectivement plus de 50 % des rapports) concernaient des intoxications par des agents chimiques (12,5 % des événements notifiés), des infections par des virus faiblement pathogènes de l'influenza aviaire (11,9 %), des infections à Salmonella enterica (10,8 %), des infections à Pasteurella spp. (8,4 %) et des infections à Trichomonas spp. chez les oiseaux et les reptiles (7,5 %). Les rapports rendaient compte de la présence de maladies chez 501 espèces, dont 19,2 % sont inscrites sur la Liste rouge des espèces menacées de l'Union internationale pour la conservation de la nature (UICN) dans la catégorie des espèces menacées d'extinction, et dont 30,7 % sont protégées au titre de la Convention sur le commerce international des espèces de faune et de flore sauvages menacées d'extinction (CITES). Les résultats de cette analyse laissent penser qu'il existe un déficit d'information, y compris par aires géographiques, parmi d'autres biais. Une notification plus systématique des maladies des animaux sauvages et le recours à ces informations lors des évaluations de la biodiversité et des prises de décision se traduiraient par une meilleure coordination entre la santé animale et la conservation de la faune, dans un contexte Une seule santé.

Cada vez está más aceptado que las enfermedades son una posible amenaza para las poblaciones de animales silvestres y la conservación de especies en peligro. El «Sistema mundial de seguimiento de las enfermedades de los animales salvajes¼ (WAHIS-Wild ) de la Organización Mundial de Sanidad Animal (OIE) constituye el más importante portal mundial de información sobre eventos de enfermedad en la fauna silvestre, compilada a partir de los informes que voluntariamente envían los países sobre enfermedades no incluidas en la lista de la OIE. En este estudio se analizaron las notificaciones recibidas durante el primer decenio de WAHIS-Wild con el objetivo de determinar tendencias y examinar su relevancia para la conservación. De 2008 a 2018, se notificaron en total 4.229 eventos de enfermedad en animales silvestres, la mayoría de ellos en el continente europeo. Las notificaciones, una vez uniformizada la nomenclatura para descartar sinonimias, cubrían 54 enfermedades anteriores o actuales no inscritas en la lista de la OIE. Las enfermedades más comunes (que en conjunto suponen más del 50% de los informes) fueron las intoxicaciones por productos químicos (un 12,5% de los episodios notificados), infecciones por virus de influenza aviar de baja patogenicidad (un 11,9%), infecciones por Salmonella enterica (un 10,8%), infección por Pasteurella spp. (un 8,4%) e infecciones de aves y reptiles por Trichomonas spp. (un 7,5%). Los informes dan cuenta de enfermedades en 501 especies distintas, de las cuales, el 19,2% están en riesgo de extinción según la Lista Roja de Especies Amenazadas de la Unión Internacional para la Conservación de la Naturaleza (UICN), y el 30,7% están protegidas por la Convención sobre el Comercio Internacional de Especies Amenazadas de Fauna y Flora Silvestres (CITES). Los resultados sugieren la existencia de vacíos de información, como por ejemplo, por área geográfica, entre otros sesgos. Una notificación más sistemática de las enfermedades de los animales silvestres y un uso de esta información en evaluaciones de la biodiversidad y en la toma de decisiones permitiría una mayor coordinación en materia de sanidad y conservación, en un contexto de «Una sola salud¼.

Rabies as a threat to wildlife.

The impact of infectious disease may become progressively more harmful to a species' survival as a wild population approaches an 'extinction vortex'. This risk is especially relevant for pathogens that spread rapidly and result in high mortality rates. Rabies, a virus that infects many mammalian species, can be efficiently transmitted through infected saliva, and is fatal without prior vaccination or rapid post-exposure prophylaxis (in humans). The authors conducted an extensive literature review to identify all wild mammal species reported to have been infected with rabies virus. They found reports of infection in 190 mammalian species, including 16 with elevated risk of extinction and two for which rabies is a direct conservation threat: the Ethiopian wolf (Canis simensis) and the African wild dog (Lycaon pictus). This paper discusses selected examples in which rabies has contributed to the population decline of a species of conservation concern. In addition, the authors note the importance of the transmission of rabies virus (RABV) from domestic dogs to wildlife, and the many challenges associated with the vaccination of wild animals. With this in mind, they present potential solutions to reduce the burden of rabies on wildlife. Once stable control of RABV is achieved in domestic dogs, remaining rabies threats to wildlife conservation can be addressed more effectively.

L'impact des maladies infectieuses peut constituer une menace croissante pour la survie d'espèces animales sauvages dès lors que leurs populations sont entraînées dans la « spirale de l'extinction ¼. Ce risque se pose plus particulièrement lorsqu'il s'agit d'agents pathogènes qui se propagent rapidement et induisent un taux de mortalité élevé. Le virus de la rage affecte un grand nombre d'espèces de mammifères et se transmet facilement par contact avec de la salive infectée ; l'infection virale entraîne la mort en l'absence d'une vaccination préalable ou, chez l'être humain, d'une prophylaxie post-exposition administrée rapidement. Les auteurs ont procédé à un examen exhaustif de la littérature afin d'inventorier les espèces de mammifères sauvages chez qui l'infection rabique a été rapportée. Des cas ont été notifiés chez 190 espèces de mammifères, dont 16 présentant un risque élevé d'extinction et deux directement menacées d'extinction en raison de la rage : le loup d'Abyssinie (Canis simensis) et le lycaon (Lycaon pictus). Les auteurs apportent des précisions sur un nombre choisi d'espèces vulnérables ou en danger dont le déclin des populations est en partie imputé à la rage. En outre, ils soulignent l'importance de la transmission du virus de la rage des chiens domestiques aux animaux sauvages et décrivent les nombreuses difficultés liées à la vaccination de la faune sauvage. Ces éléments établis, ils présentent quelques solutions envisageables pour réduire le fardeau de la rage dans la faune sauvage. Une fois le virus de la rage contrôlé de manière pérenne chez le chien domestique il sera possible de lutter plus efficacement contre les autres menaces que la rage fait peser sur la conservation de la faune.

Una enfermedad infecciosa puede tener efectos cada vez más dañinos en la supervivencia de una especie a medida que una población silvestre se va aproximando a un «vórtice de extinción¼. Este riesgo tiene especial importancia en el caso de patógenos que se propagan con rapidez y causan elevadas tasas de mortalidad. La rabia, enfermedad provocada por un virus que infecta a muchas especies de mamíferos y puede transmitirse eficazmente a través de saliva infectada, resulta letal en ausencia de vacunación previa o de rápidas medidas de profilaxis tras la exposición (en el ser humano). Los autores realizaron un amplio estudio bibliográfico para determinar todas aquellas especies de mamíferos silvestres en que se hubiera descrito una infección por el virus de la rabia. Encontraron infecciones descritas en 190 especies de mamíferos, de las que 16 presentan un elevado riesgo de extinción y dos cuya conservación se ve directamente amenazada por la rabia: el lobo etíope (Canis simensis) y el licaón, o perro salvaje africano (Lycaon pictus). Los autores exponen una serie de ejemplos en los que la rabia ha contribuido al declive demográfico de una especie cuya pervivencia está en mayor o menor peligro. Los autores señalan además la importancia que reviste la transmisión del virus de la rabia de los perros domésticos a la fauna silvestre y los numerosos problemas que presenta la vacunación de los animales silvestres. Teniendo presente esta dificultad, exponen posibles soluciones para reducir la carga de rabia en la fauna silvestre. Una vez se logre estabilizar el control del virus rábico en el perro doméstico, será posible combatir más eficazmente la amenaza que representa para la conservación de las especies silvestres.

Summarizing US Wildlife Trade with an Eye Toward Assessing the Risk of Infectious Disease Introduction.

The aim of this study was to characterize the role of the USA in the global exchange of wildlife and describe high volume trade with an eye toward prioritizing health risk assessment questions for further analysis. Here we summarize nearly 14 years (2000-2013) of the most comprehensive data available (USFWS LEMIS system), involving 11 billion individual specimens and an additional 977 million kilograms of wildlife. The majority of shipments contained mammals (27%), while the majority of specimens imported were shells (57%) and tropical fish (25%). Most imports were facilitated by the aquatic and pet industry, resulting in one-third of all shipments containing live animals. The importer reported origin of wildlife was 77.7% wild-caught and 17.7% captive-reared. Indonesia was the leading exporter of legal shipments, while Mexico was the leading source reported for illegal shipments. At the specimen level, China was the leading exporter of legal and illegal wildlife imports. The number of annual declared shipments doubled during the period examined, illustrating continually increasing demand, which reinforces the need to scale up capacity for border inspections, risk management protocols and disease surveillance. Most regulatory oversight of wildlife trade is aimed at conservation, rather than prevention of disease introduction.

Biosurveillance: a systematic review of global infectious disease surveillance systems from 1900 to 2016.

Biosurveillance is crucial to detect, identify and minimise the negative consequences of infectious disease. Its value to society and importance to global public health and global health security are growing. Despite the long history and global importance of biosurveillance, a systematic review of all existing biosurveillance systems across the 'One Health' spectrum has not yet been published. This study conducted a systematic review to identify all extant and defunct biosurveillance systems from 1900 to 2016. Of the 815 systems examined, the majority surveyed human, animal or plant data discretely. Some 105 collected human and animal data, whereas only 31 collected data on all three categories. The authors found a large increase in the number of global biosurveillance systems between 1900 and 2008, but a reduction in the number of biosurveillance systems from 2008 to the present. The number of syndromic systems created, versus laboratory-based biosurveillance systems, increased rapidly after 1980 across the globe.

La surveillance biologique est un procédé essentiel pour détecter, caractériser et minimiser les effets négatifs des maladies infectieuses. Son rôle à l'égard de la société et son importance pour la santé publique et la sécurité sanitaire mondiale ne cessent de croître. Malgré l'histoire déjà longue et l'importance mondiale de la surveillance biologique, aucun inventaire systématique des systèmes de surveillance biologique mis en œuvre dans une perspective « Une seule santé ¼ n'avait été publié jusqu'à ce jour. La présente étude résume les résultats d'un examen systématique portant sur tous les systèmes de surveillance biologique appliqués entre 1900 et 2016, qu'ils aient été arrêtés ou qu'ils soient encore utilisés aujourd'hui. La majorité des 815 systèmes examinés exploite des données relatives soit aux êtres humains, soit aux animaux, soit aux plantes. Près de 105 systèmes recueillent à la fois des données sur l'être humain et sur les animaux et 31 systèmes seulement recueillent des données sur les trois catégories en même temps. Les auteurs ont constaté une forte augmentation du nombre de systèmes de surveillance biologique dans le monde entre 1900 à 2008, puis un déclin de ce nombre entre 2008 et aujourd'hui. Le nombre de systèmes syndromiques, par opposition aux systèmes de surveillance biologique basés sur les examens de laboratoire a connu une augmentation rapide dans le monde entier à partir de 1980.

La vigilancia biológica (o biovigilancia), indispensable para discernir, detectar y reducir al mínimo las consecuencias negativas de una enfermedad infecciosa, reviste cada vez más interés para la sociedad y más importancia para la salud pública y la seguridad sanitaria mundiales. Pese a la dilatada historia y a la relevancia mundial de la vigilancia biológica, hasta ahora nunca se había publicado un examen sistemático de todos los sistemas de biovigilancia existentes dentro del espectro de «Una sola salud¼. Los autores describen un estudio encaminado a examinar de forma sistemática todos los sistemas de vigilancia biológica, aún vigentes o ya extintos, instaurados entre 1900 y 2016. La mayoría de los 815 sistemas examinados estaban dedicados a la vigilancia específica de las personas, los animales o las plantas. En unos 105 se obtenían datos de humanos y anímales, y solo en 31 de ellos se recogían datos de las tres categorías. Los autores observaron un marcado incremento del número de sistemas mundiales de biovigilancia entre 1900 y 2008, número que en cambio se fue reduciendo a partir de 2008. De 1980 en adelante se aceleró en todo el globo la creación de sistemas sindrómicos, por oposición a sistemas de biovigilancia basados en el trabajo en laboratorio.

Emerging infectious disease risk: shared drivers with environmental change.

Outbreaks of emerging infectious diseases (EIDs) seemingly appear without warning, severely exacerbating public and animal health burdens and spreading across borders. Since 1940, the rate of infectious disease emergence events has risen. Given the considerable economic and other societal costs associated with EIDs, understanding the specific drivers of these diseases and developing concrete measures to prevent and mitigate their spread is urgently needed in both health security and sustainable development discussions. Human modification of the environment serves as an underlying driver in EID risk: environmental change thus warrants consideration in surveillance and outbreak investigations to identify the origin of the disease and contribute to the development of effective actions to prevent, prepare for or reduce the risk of future events. Coordinated approaches to address the underlying and, in some cases, overlapping causes of both disease emergence and global environmental change may yield benefits for sustainable and healthy solutions to meet or reshape the demands of a growing global population and contribute to global health security.

Les foyers de maladies infectieuses émergentes semblent surgir sans signes annonciateurs préalables, ce qui aggrave considérablement leur impact sur la santé publique et la santé animale ainsi que leur capacité de propagation transfrontalière. Depuis 1940, le taux d'émergence des maladies infectieuses n'a cessé de croître. Compte tenu des coûts économiques et sociétaux au sens large associés à l'émergence de maladies infectieuses, la nécessité de mieux comprendre les facteurs déclenchants spécifiques de ces maladies et de mettre en œuvre des mesures concrètes pour prévenir et atténuer leur propagation fait partie des impératifs de la sécurité sanitaire et du développement durable. Les modifications de l'environnement dues à l'action de l'homme constituent un facteur sous-jacent du risque d'émergence de maladies infectieuses. Par conséquent, le changement environnemental doit être pris en compte lors de la surveillance d'une maladie et des enquêtes sur les foyers, afin de retracer l'origine de la maladie et de contribuer à la conception de mesures efficaces visant à prévenir les risques de nouveaux épisodes, à s'y préparer ou à les atténuer. L'adoption de méthodes concertées pour faire face aux causes sous-jacentes respectives (et parfois imbriquées) de l'émergence des maladies et du changement environnemental à l'échelle mondiale peut se révéler bénéfique pour concevoir des solutions durables et saines permettant de satisfaire ou de remodeler les exigences d'une population mondiale croissante, et de contribuer à la sécurité sanitaire mondiale.

Los brotes de enfermedades infecciosas emergentes parecen surgir sin previo aviso, propagándose allende las fronteras e imponiendo un duro tributo a la salud pública y la sanidad animal. El ritmo de aparición de enfermedades infecciosas viene acelerándose desde el decenio de 1940. Para toda reflexión sobre cuestiones de seguridad sanitaria y desarrollo sostenible, y habida cuenta de los considerables costes económicos y de otra índole que las enfermedades infecciosas emergentes entrañan para la sociedad, es urgente profundizar en los factores específicos que dan origen a estas enfermedades y definir medidas concretas para prevenir y contener su propagación. La modificación del medio por obra del hombre es un factor subyacente que acrece el riesgo de enfermedades infecciosas emergentes: por ello, al efectuar labores de vigilancia o investigar un brote con el fin de descubrir el origen de la enfermedad y ayudar a definir medidas eficaces para prevenirla, prepararse para nuevos episodios o reducir el riesgo de que se produzcan, merece la pena tener en cuenta la función que cumple en esa dinámica el cambio ambiental. El uso de planteamientos coordinados para abordar los factores subyacentes y, en ciertos casos, superpuestos que provocan tanto la aparición de enfermedades como el cambio ambiental planetario puede resultar provechoso para dar con soluciones saludables y duraderas que permitan satisfacer o modular las demandas de una población mundial cada vez más numerosa y contribuir a la seguridad sanitaria del planeta.

Risk Prioritization Tool to Identify the Public Health Risks of Wildlife Trade: The Case of Rodents from Latin America.

Wildlife trade (both formal and informal) is a potential driver of disease introduction and emergence. Legislative proposals aim to prevent these risks by banning wildlife imports, and creating 'white lists' of species that are cleared for importation. These approaches pose economic harm to the pet industry, and place substantial burden on importers and/or federal agencies to provide proof of low risk for importation of individual species. As a feasibility study, a risk prioritization tool was developed to rank the pathogens found in rodent species imported from Latin America into the United States with the highest risk of zoonotic consequence in the United States. Four formally traded species and 16 zoonotic pathogens were identified. Risk scores were based on the likelihood of pathogen release and human exposure, and the severity of the disease (consequences). Based on the methodology applied, three pathogens (Mycobacterium microti, Giardia spp. and Francisella tularensis) in one species (Cavia porcellus) were ranked as highest concern. The goal of this study was to present a methodological approach by which preliminary management resources can be allocated to the identified high-concern pathogen-species combinations when warranted. This tool can be expanded to other taxa and geographic locations to inform policy surrounding the wildlife trade.

Is One Health delivering results? Introduction.

The One Health concept is responsible for a shift towards practices, policies and partnerships that better link the health of people, animals and our shared environments. The papers in this issue of the World Organisation for Animal Health Scientific and Technical Review illustrate a myriad of ways in which a One Health approach could advance or has already advanced human and animal well-being. Independently, the authors conducted their own thematic analysis of One Health activities and found strong support for the notion that One Health has inspired a renaissance in veterinary public health, increased our basic knowledge of the mechanisms and natural history of many animal diseases, promoted systems approaches to health issues and encouraged stronger cross-sectoral collaboration. Unfortunately, many collaborations often end when funding ends and many remain distinct partnerships. One Health still suffers from a lack of strong environmental stakeholders and has mostly worked on infectious disease rather than addressing many of the pressing determinants of health that will confront us in the next century. There is no shared conception of health across veterinary, medical and environment sectors, and this is an issue that must be confronted if there are to be programmes that are truly integrated across people, animals and the environment.

Understanding the ecological drivers of avian influenza virus infection in wildfowl: a continental-scale study across Africa.

Despite considerable effort for surveillance of wild birds for avian influenza viruses (AIVs), empirical investigations of ecological drivers of AIV prevalence in wild birds are still scarce. Here we used a continental-scale dataset, collected in tropical wetlands of 15 African countries, to test the relative roles of a range of ecological factors on patterns of AIV prevalence in wildfowl. Seasonal and geographical variations in prevalence were positively related to the local density of the wildfowl community and to the wintering period of Eurasian migratory birds in Africa. The predominant influence of wildfowl density with no influence of climatic conditions suggests, in contrast to temperate regions, a predominant role for inter-individual transmission rather than transmission via long-lived virus persisting in the environment. Higher prevalences were found in Anas species than in non-Anas species even when we account for differences in their foraging behaviour (primarily dabbling or not) or their geographical origin (Eurasian or Afro-tropical), suggesting the existence of intrinsic differences between wildfowl taxonomic groups in receptivity to infection. Birds were found infected as often in oropharyngeal as in cloacal samples, but rarely for both types of sample concurrently, indicating that both respiratory and digestive tracts may be important for AIV replication.

Collaborative research approaches to the role of wildlife in zoonotic disease emergence.

Emerging infectious diseases are a key threat to public health and the majority are caused by zoonotic pathogens. Here we discuss new collaborative approaches to understanding the process of zoonotic disease emergence that link veterinary medicine, public health, and ecological approaches: conservation medicine and one health. We demonstrate how studies on the underlying drivers of disease emergence (bushmeat hunting, wildlife trade, and deforestation) can provide ways to model, predict, and ultimately prevent zoonotic disease emergence and spread.

Sylvatic transmission of arboviruses among Bornean orangutans.

Wild populations of nonhuman primates live in regions of sylvatic arbovirus transmission. To assess the status of arbovirus transmission in Bornean forests and the susceptibility of wild orangutans to arboviral infection, blood samples of wild orangutans, semi-captive orangutans, and humans were examined. Samples were tested by plaque reduction neutralization test for antibodies to viruses representing three families (Flaviviridae, Alphaviridae, and Bunyaviridae), including dengue-2, Japanese encephalitis, Zika, Langat, Tembusu, Sindbis, Chikungunya, and Batai viruses. Both wild and semi-captive orangutan groups as well as local human populations showed serologic evidence of arbovirus infection. The presence of neutralizing antibodies among wild orangutans strongly suggests the existence of sylvatic cycles for dengue, Japanese encephalitis, and sindbis viruses in North Borneo. The present study demonstrates that orangutans are susceptible to arboviralinfections in the wild, although the impact of arboviral infections on this endangered ape remain unknown.

Serum antigen 85 levels in adjunct testing for active mycobacterial infections in orangutans.

Diagnosis of active mycobacterial disease in orangutans (Pongo pygmaeus) has been impeded by high levels of non-specific intradermal skin test reactivity to mycobacterial antigens. This may be due in part to cross reactivity between antigens, tuberculin concentrations used or other species-specific factors. Antigen 85 (Ag85) complex proteins are major secretory products of actively growing mycobacteria, and measurement of serum Ag85 could provide a method for determining active mycobacterial infections that was not dependent on host immunity. Serum Ag85 was measured by dot-immunobinding assay using monoclonal anti-Ag85, purified Ag85 standard and enhanced chemiluminescence technology in coded serum samples from 14 captive orangutans from a zoo in Colorado, 15 semi-captive orangutans in Malaysia, and 19 free-ranging wild orangutans in Malaysia. Orangutans from Colorado (USA) were culture negative for Mycobacterium tuberculosis and M. avium, although all had laboratory suspicion or evidence of mycobacterial infection; median serum Ag85 was 10 microU/ml (range, <0.25-630 microU/ml). Of the semi-captive orangutans, six were skin test reactive and two were culture positive for M. avium on necropsy. Median serum Ag85 for this group was 1,880 microU/ml (0.75-7,000 microU/ml), significantly higher than that of Colorado zoo or free-ranging Malaysian orangutans. Median serum Ag85 in the latter group was 125 microU/ml (range, 0.75-2,500 microU/ml). These data suggest that suggest that additional studies using more specific reagents and more samples from animals of known status are appropriate.

Infectious disease serologic survey in free-ranging Venezuelan anacondas (Eunectes murinus).

Reptiles can harbor pathogenic microorganisms asymptomatically and serve as potential reservoirs of infection for humans, domestic animals, and other reptiles. Infectious diseases are also problematic for free-ranging reptile populations and are an important consideration in reptile reintroduction and translocation projects. There have been limited serologic studies of free-ranging reptiles for evidence of exposure to potential pathogens. In the present study, serum or plasma samples from five male and five female free-ranging Venezuelan anacondas (Eunectes murinus) were screened for antibodies to eastern, western, and Venezuelan equine encephalitis viruses, vesicular stomatitis virus, ophidian paramyxovirus, 19 Leptospira interrogans serovars, and Cryptosporidium serpentes. Antibodies to these agents were not detected, or antibody titers were low and possibly nonspecific. These results for the limited number of anacondas surveyed suggest that they do not serve as significant reservoirs for these infectious agents at this location.

Conservation medicine.

The Field Veterinary Program (FVP) of the Wildlife Conservation Society (WCS) was created in 1989 to combat the wildlife disease and health problems that increasingly complicate the process of wildlife conservation. The FVP provides veterinary services for the more than 300 WCS conservation projects located in more than 50 countries around the world. Most of these projects are in tropical regions and many have a wildlife/domestic livestock component. Wildlife health care provided by the FVP staff includes (1) identifying critical health factors; (2) monitoring health status; (3) crisis intervention; (4) developing and applying new technologies; (5) animal handling and welfare concerns; and (6) training. Additionally, the staff of the FVP give expert advice to many governmental and non-governmental agencies that are involved in setting policies directly related to wildlife health and conservation issues. In this paper, two FVP projects are presented as examples of studies that have increased our understanding of the role wildlife diseases may play in the health of livestock and human populations, as well as the role humans and livestock may play in the health of wildlife populations. Examples of the collaborative work between the FVP staff and scientists from many disciplines (e.g., acarologists, mycobacterium experts, ecologists, and biologists) are also presented.

Health evaluation of free-ranging rockhopper penguins (Eudyptes chrysocomes) in Argentina.

As part of annual colony counts in Santa Cruz Province, Argentina, a health survey of rockhopper penguins (Eudyptes chrysocomes) was conducted in 1994. Forty-five birds were examined during handling procedures, and blood and fecal samples were collected for laboratory analysis. All birds appeared to be in good condition. No ecto- or endoparasites were found. Hematology, plasma chemistry, and plasma mineral levels were measured and correlated with the results of bacterial and viral serology. Antibodies against Chlamydia sp., avian adenovirus, avian encephalomyelitis virus, infectious bronchitis virus, avian reovirus, and paramyxovirus-1, -2, and -3 were found. Mean plasma chemistry and mineral values differed between individuals testing positive and negative on serologic tests. There was no serologic evidence of exposure to avian influenza virus, duck viral enteritis, infectious bursal disease, infectious laryngotracheitis, Aspergillus sp., or Salmonella pullorum. Trace amounts of endrin were found in the plasma of one bird, but all other chlorinated pesticide and polychlorinated biphenyl levels were below detectable limits.

Health evaluation of free-ranging guanaco (Lama guanicoe).

Twenty free-ranging guanaco (Lama guanicoe) in Chubut Province, Argentina, were immobilized for health evaluations. All but two animals appeared to be in good condition. Hematology, serum chemistry, and vitamin and mineral levels were measured, and feces were evaluated for parasites. Serology tests included bluetongue, brucellosis, bovine respiratory syncitial virus, bovine viral diarrhea/mucosal disease, equine herpesvirus 1, infectious bovine rhinotracheitis, Johne's disease (Mycobacterium paratuberculosis), foot and mouth disease, leptospirosis (17 serovars), parainfluenza-3, and vesicular stomatitis. Blood samples from 20 domestic sheep (Ovis aries) maintained in the same reserve with the guanaco were also collected at the same time for serology tests. No guanaco had positive serologic tests. Sheep were found to have antibody titers to bovine respiratory syncytial virus, Johne's disease, leptospirosis, and parainfluenza-3. There was no apparent difference in external appearance or condition, or statistical difference in blood test values, between the animals that were positive or negative for parasite ova.

Wild primate populations in emerging infectious disease research: the missing link?

Wild primate populations, an unexplored source of information regarding emerging infectious disease, may hold valuable clues to the origins and evolution of some important pathogens. Primates can act as reservoirs for human pathogens. As members of biologically diverse habitats, they serve as sentinels for surveillance of emerging pathogens and provide models for basic research on natural transmission dynamics. Since emerging infectious diseases also pose serious threats to endangered and threatened primate species, studies of these diseases in primate populations can benefit conservation efforts and may provide the missing link between laboratory studies and the well-recognized needs of early disease detection, identification, and surveillance.

Immobilization and health assessment of free-ranging black spider monkeys (Ateles paniscus chamek).

Eight free-ranging black spider monkeys (Ateles paniscus chamek) were immobilized with Telazol in Bolivia for the purpose of radio-collaring. During this procedure, the animals received complete medical examinations, and samples were collected for health analyses. Biochemical test results varied with the degree of condition of the animals, and a variety of physical abnormalities were found. Evidence of previous infections with Leptospira sp., encephalitis virus, and yellow fever virus was found. All findings contribute to establishing baseline health values for the species. The handling of primates for research projects provides a valuable opportunity to collect health-related data and samples that can contribute to wildlife management and conservation efforts. The capture and handling of free-ranging primates is always accompanied by risk of injury or mortality. It is ethically important to maximize the amount of information gathered during these procedures. Furthermore, sharing the undesirable impacts with the scientific community enables informed decisions to be made during future project development.