Cancer in the Wilderness.

How a chance discovery in the Tasmanian rainforest changed the course of my scientific career.

New threats in the recovery of large carnivores inhabiting human-modified landscapes: the case of the Cantabrian brown bear (Ursus arctos).

Understanding mortality causes is important for the conservation of endangered species, especially in small and isolated populations inhabiting anthropized landscapes where both natural and human-caused mortality may hinder the conservation of these species. We investigated the mortality causes of 53 free-ranging brown bears (Ursus arctos) found dead between 1998 and 2023 in the Cantabrian Mountains (northwestern Spain), a highly human-modified region where bears are currently recovering after being critically threatened in the last century. We detected natural traumatic injuries in 52.63% and infectious diseases in 39.47% of the 38 bears for which the mortality causes were registered, with 21.05% of these cases presenting signs of both infectious diseases and traumas. More specifically, almost 30% of the bears died during or after intraspecific fights, including sexually selected infanticide (10.53%). In addition, primary infectious diseases such as infectious canine hepatitis, distemper, clostridiosis and colibacillosis caused the death of 15.79% of the bears. The number of direct human-caused deaths (i.e., shooting, poisoning, snare) decreased over the study period. This study also reveals three new mortality causes triggered by pathogens, two of which-Clostridium novyi and verotoxigenic Escherichia coli-not previously described in ursids, and the other one, canine distemper virus, never reported in brown bears as cause of death. New management strategies for the conservation of Cantabrian bears, which are urgently needed due to the rapid expansion of the population, should consider the mortality causes described in this study and must promote further research to elucidate how the high prevalence of infectious diseases may threaten the current recovery of the population.

Mapping the scientific output of organoids for animal and human modeling infectious diseases: a bibliometric assessment.

The escalation of antibiotic resistance, pandemics, and nosocomial infections underscores the importance of research in both animal and human infectious diseases. Recent advancements in three-dimensional tissue cultures, or "organoids", have revolutionized the development of in vitro models for infectious diseases. Our study conducts a bibliometric analysis on the use of organoids in modeling infectious diseases, offering an in-depth overview of this field's current landscape. We examined scientific contributions from 2009 onward that focused on organoids in host‒pathogen interactions using the Web of Science Core Collection and OpenAlex database. Our analysis included temporal trends, reference aging, author, and institutional productivity, collaborative networks, citation metrics, keyword cluster dynamics, and disruptiveness of organoid models. VOSviewer, CiteSpace, and Python facilitated this analytical assessment. The findings reveal significant growth and advancements in organoid-based infectious disease research. Analysis of keywords and impactful publications identified three distinct developmental phases in this area that were significantly influenced by outbreaks of Zika and SARS-CoV-2 viruses. The research also highlights the synergistic efforts between academia and publishers in tackling global pandemic challenges. Through mostly consolidating research efforts, organoids are proving to be a promising tool in infectious disease research for both human and animal infectious disease. Their integration into the field necessitates methodological refinements for better physiological emulation and the establishment of extensive organoid biobanks. These improvements are crucial for fully harnessing the potential of organoids in understanding infectious diseases and advancing the development of targeted treatments and vaccines.

Prevalence and spatial distribution of infectious diseases of dairy cattle in Ontario, Canada.

We investigated the prevalence and spatial distribution of selected pathogens associated with infectious diseases of dairy cattle in Ontario, Canada. The cross-sectional study surveyed bulk tank milk for antibodies against bovine leukemia virus (BLV), Mycobacterium avium ssp. paratuberculosis (MAP), and Salmonella Dublin, and for the presence of mastitis pathogens (Staphylococcus aureus, Streptococcus agalactiae, Mycoplasma bovis). Between October 2021 and June 2022, bulk tank milk samples were obtained from every commercial dairy farm in Ontario (n = 3,286). Samples underwent ELISA testing for the presence of BLV, MAP, and S. Dublin antibodies, and quantitative PCR testing for the detection of specific antigens of pathogens associated with mastitis. Bayesian models were used to estimate prevalence, and spatial analysis was carried out to identify regional clusters of high pathogen prevalence. Prevalence varied for different pathogens, and BLV was widespread across dairy farms in Ontario, with an estimated prevalence of 88.3%. The prevalence of MAP, Staph. aureus and S. Dublin in Ontario dairy herds was 39.8%, 31.5%, and 5.1%, respectively. The vast majority of dairy herds in Ontario were free of intramammary infections caused by Strep. agalactiae and M. bovis. Clusters of increased positive test rates were detected for S. Dublin, MAP, and Staph. aureus, indicating potential geographic risk factors for pathogen transmission. For S. Dublin, an area of increased test positivity rates was detected in southwestern Ontario, close to the Canada-United States border where most of the dairy herds in Ontario are located. Conversely, a localized cluster of positive test outcomes involving 14 subdivisions located in the southeastern region of Ontario was detected for Staph. aureus. Findings from our survey highlight the importance of the testing of aggregated samples and conducting spatial analysis as part of disease surveillance programs, and for implementing risk-based trading approaches among dairy producers.

Infectious sporadic bovine abortions: retrospective analysis.

Infectious sporadic abortions in cattle are mainly caused by opportunistic bacteria and fungi usually present in environmental or gastrointestinal and reproductive microbiota of healthy animals. A retrospective analysis was carried out to evaluate the main opportunistic microorganisms involved in bovine abortions recorded at INTA Balcarce (Argentina) from 1997 to 2023, accounting for 2.2% of the total diagnosed etiologies of bovine abortion. The opportunistic agents identified as the cause of abortion in 29 fetuses were bacteria (90%) and fungi (10%). Escherichia coli (n = 8), Trueperella pyogenes (n = 5), and Histophilus somni (n = 4) were the bacterial species most often identified as causing infectious abortions, whereas Aspergillus spp. (n = 3) was implicated in all fungal abortions identified. Pure culture of bacteria or fungus was achieved from abomasal content and/or lung essential. Main microscopic findings were bronchopneumonia, myo- and epicarditis, meningitis, and portal hepatitis. Herein, we highlight the importance of detecting potential infectious bacteria in cultures to improve etiological diagnosis of bovine abortions associated with compatible microscopic findings to confirm the etiology.

A 30 YEAR (1991-2020) RETROSPECTIVE MORTALITY REVIEW OF GIRAFFIDS (GIRAFFA SPP. AND OKAPIA JOHNSTONI) IN MANAGED CARE.

Identifying common causes of mortality in zoo giraffe (Giraffa spp.) and okapi (Okapia johnstoni) provides an opportunity to help improve welfare and population management for these endangered species. Mortality reports from 1,024 giraffe and 95 okapi in zoos were compiled from the Species 360 Zoological Information Management Software (ZIMS) utilizing the Morbidity & Mortality Analysis tool. Thirty years of mortality reports (1991-2020) were evaluated to help identify trends and evaluate the impacts, if any, of changes over time in husbandry and management practices. The most common causes of death for giraffe from 1991 to 2015 were neonatal issues (234/845, 27.7%), trauma (213/845, 25.2%), noninfectious disease (190/845, 22.5%), and infectious disease (188/845, 22.2%). In comparison, the most common causes of mortality for giraffe from 2016 to 2020, were noninfectious disease (78/179, 43.6%), trauma (39/179, 21.8%), neonatal issues (39/179, 21.8%), and infectious disease (17/179, 9.5%). The most common cause of death for okapi from 1991 to 2015 were neonatal issues (29/64, 45.3%), infectious disease (13/64, 20.3%), noninfectious disease (11/64, 17.2%), and trauma (10/64, 15.6%). In comparison, the most common cause of death for okapi from 2016 to 2020 was noninfectious disease (15/31, 48.4%), neonatal issues (8/31, 25.8%), and infectious disease (5/31, 16.1%). The results suggest that zoo giraffids have had a relative decrease in mortality from infectious diseases in recent years, whereas death from noninfectious causes has increased significantly. Trauma-related giraffe mortalities and neonatal mortality in both giraffe and okapi, although decreasing in prevalence between time periods, continue to be important causes of death in zoos. This is the first descriptive mortality review for the Giraffidae family and provides data on potential giraffe and okapi health issues that zoos could proactively address.

Protein Expression Profiles in Exosomes of Bovine Mammary Epithelial Cell Line MAC-T Infected with Staphylococcus aureus.

Mastitis is a common and widespread infectious disease in dairy farms around the world, resulting in reduced milk production and quality. Staphylococcus aureus is one of the main pathogenic bacteria causing subclinical mastitis in dairy cows. S. aureus can activate inflammatory signaling pathways in bovine mammary epithelial cells. Exosomes produced by cells can directly transfer pathogen-related molecules from cell to cell, thus affecting the process of infection. Protein is the material basis of the immune defense function in the body; therefore, a comprehensive comparison of proteins in exosomes derived from S. aureus-infected (SA group) and normal (control group [C group]) bovine mammary epithelial MAC-T cells was performed using shotgun proteomics by a DIA approach. A total of 7,070 proteins were identified and quantified. Compared with the C group, there were 802 differentially expressed proteins (DEPs) identified in the SA group (absolute log2 fold change [|log2FC|] of ≥0.58; false discovery rate [FDR] of <0.05), among which 325 proteins were upregulated and 477 were downregulated. The upregulated proteins, including complement 3 (C3), integrin alpha-6 (ITGA6), apolipoprotein A1 (APOA1), annexin A2 (ANXA2), tripeptidyl peptidase II (TPP2), keratin 8 (KRT8), and recombinant desmoyokin (AHNAK), are involved mostly in host defense against pathogens, inflammation, and cell structure maintenance. KEGG enrichment analysis indicated that DEPs in S. aureus infection were involved in the complement and coagulation cascade, phagosome, extracellular matrix (ECM)-receptor interaction, and focal adhesion pathways. The results of this study provide novel information about proteins in the exosomes of MAC-T cells infected with S. aureus and could contribute to an understanding of the infectious mechanism of bovine mastitis. IMPORTANCE Mastitis is a widespread infectious disease in dairy farms, resulting in reduced milk production and quality. Staphylococcus aureus is one of the main pathogenic bacteria causing subclinical mastitis. Exosomes contain proteins, lipids, and nucleic acids, which are involved in many physiological and pathological functions. The expression of proteins in exosomes derived from bovine mammary epithelial cells infected by S. aureus is still barely understood. These results provide novel information about MAC-T-derived exosomal proteins, reveal insights into their functions, and lay a foundation for further studying the biological function of exosomes during the inflammatory response.

Ophthalmic and immunopathological characterization of systemic infectious diseases in cats.

Ocular involvement in systemic diseases is frequent in cats; however, without concurrent clinical and ophthalmic examinations with gross and/or histologic analysis of the eye, these findings can be underdiagnosed. This article aims to provide gross, histologic, and immunohistochemical characteristics of ocular lesions from cats submitted to necropsy, focusing on those caused by systemic infectious agents. Cats that died due to a systemic infectious disease were selected based on necropsy diagnosis and presence of ocular lesions. Gross, histologic, and immunohistochemical findings were recorded. From April 2018 to September 2019, 849 eyes of 428 cats were evaluated. Histologic abnormalities were seen in 29% of cases, which were classified as inflammatory (41%), neoplastic (32%), degenerative (19%), and metabolic/vascular (8%). Macroscopic changes were present in one-third of eyes with histologic lesions. Of these, 40% were attributed to inflammatory or neoplastic diseases associated with infectious agents. The most important infectious agents causing ocular disease in this study were feline leukemia virus, feline infectious peritonitis virus, and Cryptococcus sp. The most common ocular abnormalities associated with infectious agents were uveitis (anterior, posterior, or panuveitis), optic neuritis, and meningitis of the optic nerve. Ocular lesions secondary to systemic infections in cats are frequent; however, these are not always diagnosed because gross lesions are less common than histologic lesions. Therefore, both gross and histologic evaluation of the eyes of cats is recommended, mainly for cases in which the clinical suspicion or necropsy diagnosis suggests that an infectious agent might be related to the cause of death.

A scoping review of the testing of bulk milk to detect infectious diseases of dairy cattle: Diseases caused by bacteria.

Testing of bulk milk (BM) samples is a convenient, cost-effective strategy that can easily be implemented as part of disease surveillance programs on dairy farms. Here, we performed a scoping review to summarize the literature reporting on the testing of BM samples to detect infectious diseases of dairy cattle caused by bacteria. We also provide a non-exhaustive, albeit significant, list of diagnostic tests that are marketed for BM samples, as well as a list of disease surveillance activities that included testing of BM samples. A literature search was carried out in 5 databases, yielding 8,829 records from which 474 were retained. Overall, 575 eligible bacterial pathogens were screened for using BM samples, ranging from 1 to 6 individual pathogens per study. Staphylococcus aureus, including methicillin-resistant Staph. aureus, were the most studied bacteria (n = 179 studies), followed by Streptococcus agalactiae (86), Mycobacterium avium ssp. paratuberculosis (79), Coxiella burnetii (79), and Mycoplasma spp. (67). Overall, culture-based protocols, ELISA, real-time PCR, and PCR were the most commonly adopted methodologies to screen BM samples. Sensitivity of BM testing for bovine paratuberculosis was generally low and varied greatly according to the ELISA cut-offs adopted and herd-level definition of disease. In general, protocols had low to moderate sensitivities (<50%), which increased for herds with high within-herd seroprevalence. Specificity of BM testing for paratuberculosis was generally high. With respect to mastitis pathogens, BM testing demonstrated high sensitivity and specificity for Strep. agalactiae, in general. However, we observed inconsistency among studies with respect to the sensitivity of BM culture to detect infected herds, which was notably higher if enrolled herds were heavily infected or had history of clinical disease. Among Salmonella spp. pathogens, Salmonella Dublin was the most frequently studied bacterium for which BM testing has been validated. Specificity of BM ELISA was high, ranging from 89.0 to 99.4. In contrast, sensitivity varied greatly among studies, ranging from 50.6% to 100%. Our findings support that one of most important factors affecting sensitivity of BM ELISA for Salmonella Dublin is whether nonlactating cattle are considered in the definition of herd infection status. In general, protocols analyzed in this review suffered from very low sensitivities, which hardly justifies their use as part of disease surveillance as single testing. Nevertheless, test sensitivity can be increased by the adoption of more inclusive definitions of disease-free herds. Further, low-sensitivity and high-specificity methods can be valuable tools for surveillance when used repeatedly over time.

Infectious disease modelling to inform policy.

With modelling becoming increasingly important in helping to inform decisions about animal diseases, it is essential that the process be optimised to gain the maximum benefit for the decision-maker. Here, the authors set out ten steps that can improve this process for all concerned. Four steps describe initialisation to ensure that the question, answer and timescale are defined; two steps describe the modelling process and quality assurance; and four steps describe the reporting stage. The authors believe that this greater emphasis at the beginning and end of a modelling project will increase the relevance of the work and understanding of the results, and thus contribute towards better decision-making.

Compte tenu de l'importance croissante de la modélisation pour documenter les décisions sur les maladies animales, il est essentiel d'optimiser le processus afin de le rendre le plus profitable possible pour les personnes décisionnaires. Les auteurs définissent dix étapes permettant d'améliorer le processus pour tous les intervenants. Quatre étapes concernent la phase de démarrage et visent à s'assurer que les questions posées, les réponses obtenues et le calendrier sont bien définis ; les deux étapes suivantes portent sur le processus de modélisation et sur l'assurance qualité ; les quatre dernières décrivent la phase d'élaboration des rapports. Les auteurs estiment que cette attention particulière accordée aux phases de démarrage et d'achèvement d'un projet de modélisation rend l'exercice plus pertinent et améliore la compréhension des résultats, ce qui contribue à une meilleure prise de décisions.

Dada la creciente importancia que está cobrando la modelización como herramienta para ayudar a fundamentar las decisiones relativas a enfermedades animales, es esencial optimizar el proceso para que las instancias decisorias puedan aprovecharlo al máximo. Los autores exponen diez pasos que pueden mejorar el proceso para cuantos trabajan en este ámbito. En cuatro pasos se describe la inicialización, que sirve para definir debidamente la pregunta, la respuesta y la escala temporal de que se trate. En otros dos pasos se describe el proceso de modelización y de garantía de calidad, mientras que en los últimos cuatro pasos se describe la fase de producción de informes. Los autores consideran que el hecho de otorgar mayor peso a las fases iniciales y finales de un proyecto de modelización hará que el trabajo gane en pertinencia y que se entiendan mejor sus resultados, lo que a su vez contribuye a un proceso más eficaz de adopción de decisiones.

Reshaping surveillance for infectious diseases: less chasing of pathogens and more monitoring of drivers.

Animal health surveillance, despite its name, tends to focus on looking for disease. Often this involves searching for cases of infection with known pathogens (â€Ëœpathogen chasing'). Such an approach is both resource intensive and limited by the requirement for prior knowledge of disease likelihood. In this paper, the authors propose the gradual reshaping of surveillance towards the systems level, focusing on the processes (â€Ëœdrivers') that promote disease or health, rather than on the presence or absence of specific pathogens. Examples of relevant drivers include land-use change, increasing global interconnectedness, and finance and capital flows. Importantly, the authors suggest that surveillance should focus on detecting changes in patterns or quantities associated with such drivers. This would generate systems-level, risk-based surveillance information to identify areas where additional attention may be needed, and, over time, inform the implementation of prevention efforts. The collection, integration and analysis of data on drivers is likely to require investment in improving data infrastructures. A period of overlap would allow the two systems (traditional surveillance and driver monitoring) to be compared and calibrated. This would also lead to a better understanding of the drivers and their linkages, and thereby generate new knowledge that can improve surveillance and inform mitigation efforts. Since surveillance of drivers may give signals when changes are occurring, which could act as alerts and enable targeted mitigation, this might even enable disease to be prevented before it happens by directly intervening in the drivers themselves. Such surveillance focused on the drivers could be expected to bring additional benefits, since the same drivers promote multiple diseases. Further, focusing on drivers rather than pathogens should enable control of currently unknown diseases, making this approach particularly timely, given the increasing risk of emergence of new diseases.

La surveillance de la santé animale a tendance, malgré son nom, à se focaliser sur la recherche des maladies. Elle implique souvent de chercher les cas d'infection par des agents pathogènes connus (" chasse aux agents pathogènes "). Ce type d'approche exige non seulement beaucoup de ressources, mais elle est aussi limitée par la nécessité d'avoir une connaissance préalable de la probabilité de survenue de la maladie en question. Dans cet article, les auteurs proposent une refonte progressive de la surveillance pour la déplacer au niveau systémique, en se concentrant sur les processus (" facteurs ") influençant la maladie ou la santé plutôt que sur la présence ou non d'agents pathogènes spécifiques. Parmi les facteurs pertinents, on peut citer les changements dans l'utilisation des sols, l'interconnexion accrue au niveau mondial et les flux financiers et de capitaux. Les auteurs soulignent cet élément important : la surveillance devrait se focaliser sur la détection de changements au niveau des schémas ou des quantités associés à ces facteurs. Cela permettrait d'obtenir des informations de surveillance au niveau systémique et basées sur les risques, afin d'identifier les domaines auxquels il pourrait être nécessaire de porter une attention particulière - ce qui informerait, à terme, la mise en oeuvre des efforts de prévention. Il est probable qu'une amélioration des infrastructures de données soit nécessaire pour assurer la collecte, l'intégration et l'analyse des données sur les facteurs. Une période de chevauchement permettrait de comparer et de calibrer les deux systèmes (surveillance traditionnelle et surveillance des facteurs). Les facteurs et les liens entre eux seraient également mieux compris, ce qui générerait de nouvelles connaissances pouvant améliorer la surveillance et informer les efforts d'atténuation. Grâce à la surveillance des facteurs, des signaux pourraient être identifiés lorsque des changements se produisent, ce qui constituerait une alerte pour que des efforts d'atténuation ciblés soient mis en place afin d'intervenir directement sur les facteurs eux-mêmes et donc prévenir une maladie avant même qu'elle ne survienne. On peut s'attendre à ce que ce type de surveillance centrée sur les facteurs apporte des bénéfices supplémentaires, puisque les mêmes facteurs peuvent favoriser de multiples maladies. De surcroît, cette orientation axée sur les facteurs plutôt que sur les agents pathogènes devrait permettre de contrôler des maladies aujourd'hui inconnues, ce qui rend cette approche d'autant plus opportune, compte tenu du risque croissant d'émergence de nouvelles maladies.

La vigilancia zoosanitaria, pese a lo que su nombre indica, tiende a centrarse en la búsqueda de enfermedades, lo que a menudo pasa por tratar de localizar casos de infección por un patógeno conocido ("persecución de patógenos"). Semejante método no solo exige cuantiosos recursos, sino que además presenta la limitación de que obliga a conocer de antemano la probabilidad de aparición de una enfermedad. Los autores proponen una remodelación gradual de la vigilancia tendente a dotarla de carácter sistémico y a centrarla no tanto en la presencia o ausencia de determinados patógenos, sino en los procesos ("inductores" o "factores de inducción", drivers) que favorecen la enfermedad o la salud. Son ejemplo de tales procesos la evolución de los usos del suelo, el creciente nivel de interconexión mundial o los flujos financieros y de capitales. Un aspecto importante que apuntan los autores es que la vigilancia debería tener por objetivo la detección de cambios en las características o cantidades de esos factores de inducción. Ello generaría información de vigilancia basada en el riesgo de carácter sistémico, que serviría para determinar aquellas zonas a las que convendría prestar más atención y, con el tiempo, fundamentar la realización de actividades de prevención. Es probable que la obtención, integración y análisis de datos sobre los factores de inducción exijan inversiones para mejorar las infraestructuras de datos. Si hubiera una fase de solapamiento, sería posible comparar y valorar los resultados de ambos sistemas (vigilancia tradicional y seguimiento de los factores de inducción). Ello serviría para entender mejor los inductores y su vinculación recíproca, lo que generaría nuevos conocimientos con los que perfeccionar la vigilancia y en los que cimentar las actividades de mitigación. Dado que la vigilancia de los inductores puede generar una señal cuando se estén produciendo cambios, señal que a su vez activaría una alerta y propiciaría medidas selectivas de mitigación, podría ser que ello sirviera incluso para prevenir una enfermedad antes de que surgiera, actuando directamente sobre los propios factores de inducción. Cabría pensar que semejante tipo de vigilancia, centrarse en los inductores, puede tener otros efectos beneficiosos, en la medida en que un mismo inductor alimenta la aparición de varias enfermedades. Además, el hecho de centrarse en los factores de inducción, y no tanto en los patógenos, debería servir para controlar enfermedades actualmente desconocidas, por lo que este planteamiento, ante el creciente riesgo de aparición de nuevas enfermedades, resulta especialmente oportuno.

Management and analysis of high-throughput sequence data for infectious animal diseases.

Advances in technology and decreasing costs have accelerated the use of high-throughput sequencing (HTS) for both diagnosis and characterisation of infectious animal diseases. High-throughput sequencing offers several advantages over previous techniques, including rapid turnaround times and the ability to resolve single nucleotide changes among samples, both of which are important for epidemiological investigations of outbreaks. However, due to the plethora of genetic data being routinely generated, the storage and analysis of these data are proving challenging in their own right. In this article, the authors provide insight into the aspects of data management and analysis that should be considered before adopting HTS for routine animal health diagnostics. These elements fall largely into three interrelated categories: data storage, data analysis and quality assurance. Each has numerous complexities and may need to be adapted as HTS evolves. Making appropriate strategic decisions about bioinformatic sequence analysis early on in project development will help to avert major issues in the long term.

Les avancées technologiques dans le domaine du séquençage à haut débit (SHD) et la diminution des coûts liés à cette technique en ont accéléré l'utilisation à des fins de diagnostic et de caractérisation des maladies animales infectieuses. Le séquençage à haut débit offre plusieurs avantages par rapport aux techniques antérieures, en particulier la rapidité de son exécution et une résolution de l'ordre d'un seul changement de nucléotide parmi plusieurs échantillons, ce qui présente un grand intérêt lors des enquêtes épidémiologiques sur les foyers. Néanmoins, la pléthore de données génétiques générées en routine par le SHD devient un véritable problème en termes de stockage et d'analyse de ces données. Les auteurs apportent un éclairage sur les aspects de la gestion et de l'analyse des données qu'il convient de prendre en compte avant d'adopter le SHD pour le diagnostic de routine en santé animale. Ces éléments relèvent de trois catégories étroitement reliées : le stockage de données, l'analyse de données et l'assurance qualité. Chacun de ces aspects présente de nombreuses complexités et nécessitera sans doute d'être adapté à mesure que le SHD évolue. Lorsqu'elles sont prises dès la phase initiale d'un projet, des décisions stratégiques appropriées en matière d'analyse bio-informatique de séquences peuvent contribuer à éviter des problèmes majeurs sur le long terme.

Los avances tecnológicos y la reducción de los costos han acelerado el uso de la secuenciación de alto rendimiento (SAR) con fines de diagnóstico y caracterización de enfermedades animales infecciosas. La secuenciación de alto rendimiento presenta varias ventajas en comparación con otras técnicas anteriores, en particular ciclos más rápidos y una resolución que permite detectar diferencias de un solo nucleótido entre las muestras, aspectos ambos de gran importancia para el estudio epidemiológico de brotes infecciosos. Sin embargo, debido al sinnúmero de datos genéticos que constantemente se generan, no es de extrañar que esté resultando problemático almacenar y analizar los datos obtenidos. Los autores arrojan luz sobre los aspectos de la gestión y el análisis de datos que conviene tener en cuenta antes de aplicar la SAR a las labores sistemáticas de diagnóstico en sanidad animal. Estos elementos corresponden a grandes líneas a tres categorías relacionadas entre sí: el almacenamiento de datos; el análisis de datos; y la garantía de calidad. Cada una de ellas presenta multitud de complicaciones y exige un proceso permanente de adaptación a medida que la técnica de secuenciación va evolucionando. El hecho de adoptar las buenas decisiones estratégicas sobre el análisis bioinformático de secuencias en los primeros momentos de la concepción de un proyecto ayudará a evitar importantes problemas a largo plazo.

Assessing the quality of data for drivers of disease emergence.

Drivers are factors that have the potential to directly or indirectly influence the likelihood of infectious diseases emerging or re-emerging. It is likely that an emerging infectious disease (EID) rarely occurs as the result of only one driver; rather, a network of sub-drivers (factors that can influence a driver) are likely to provide conditions that allow a pathogen to (re-)emerge and become established. Data on sub-drivers have therefore been used by modellers to identify hotspots where EIDs may next occur, or to estimate which sub-drivers have the greatest influence on the likelihood of their occurrence. To minimise error and bias when modelling how sub-drivers interact, and thus aid in predicting the likelihood of infectious disease emergence, researchers need good-quality data to describe these sub-drivers. This study assesses the quality of the available data on sub-drivers of West Nile virus against various criteria as a case study. The data were found to be of varying quality with regard to fulfilling the criteria. The characteristic with the lowest score was completeness, i.e. where sufficient data are available to fulfil all the requirements for the model. This is an important characteristic as an incomplete data set could lead to erroneous conclusions being drawn from modelling studies. Thus, the availability of good-quality data is essential to reduce uncertainty when estimating the likelihood of where EID outbreaks may occur and identifying the points on the risk pathway where preventive measures may be taken.

Les facteurs d'émergence sont des éléments ayant le potentiel direct ou indirect d'influencer la probabilité d'émergence ou de réémergence d'une maladie infectieuse. Il est probablement rare qu'une maladie infectieuse émergente apparaisse en raison d'un seul facteur ; c'est plutôt un faisceau de sous-facteurs (éléments pouvant avoir une influence sur un même facteur) qui contribue à ce que les conditions soient réunies pour qu'un agent pathogène puisse (ré)émerger et s'établir. Les concepteurs de modèles ont donc utilisé les données relatives aux sous-facteurs pour identifier les zones sensibles où les prochaines maladies infectieuses émergentes pourraient survenir, ou pour faire une estimation des sous-facteurs ayant la plus grande influence sur la probabilité de leur occurrence. Les chercheurs ont besoin de données de qualité pour décrire ces sous-facteurs, afin de minimiser le risque d'erreur et de biais lors de la modélisation de l'interaction entre les différents sous-facteurs, et de contribuer ainsi à mieux prédire la probabilité d'apparition d'une maladie infectieuse émergente. Les auteurs présentent une étude de cas qui a consisté à évaluer la qualité des données disponibles relatives aux sous-facteurs d'émergence du virus de la fièvre de West Nile au regard de différents critères. Il est apparu que la qualité des données était variable au regard des critères examinés. Le paramètre dont le score était le plus bas est celui de la complétude - le fait que suffisamment de données soient disponibles pour répondre à toutes les exigences du modèle. Il s'agit pourtant d'un paramètre important car des données incomplètes peuvent inciter à tirer des conclusions erronées des études de modélisation. La disponibilité de données de bonne qualité est essentielle pour réduire l'incertitude lors de l'estimation de la probabilité d'apparition de maladies infectieuses émergentes dans des zones déterminées, ainsi que pour identifier les points critiques de concrétisation du risque où des mesures préventives pourraient être mises en place.

Los inductores o factores de inducción [drivers] son aquellos que, directa o indirectamente, pueden influir en la probabilidad de que surjan o resurjan enfermedades infecciosas. Todo indica que rara vez una enfermedad infecciosa emergente aparece por efecto de un solo factor de inducción, sino que es probable que haya más bien una combinación de "subfactores de influencia" [sub-drivers] (factores que pueden influir en un inductor) que cree condiciones propicias para que un patógeno (re)surja y logre asentarse. Los creadores de modelos, por consiguiente, se han servido de datos sobre estos subfactores de influencia para localizar aquellas zonas donde con mayor probabilidad puedan aparecer próximamente enfermedades infecciosas emergentes o para determinar cuáles son los subfactores que más influyen en la probabilidad de que ello ocurra. Para reducir al mínimo los errores y sesgos al modelizar la interacción entre los subfactores y ayudar así a calcular la probabilidad de que surja una enfermedad infecciosa emergente, los investigadores necesitan datos de buena calidad para caracterizar estos subfactores. En el análisis expuesto por los autores se utilizó el virus del Nilo Occidental como ejemplo de estudio para evaluar, con arreglo a diversos criterios, la calidad de los datos existentes sobre los subfactores que inciden en la aparición de este virus. Lo que se constató, en relación con el grado de cumplimiento de los criterios, es que esos datos eran de calidad variable. La característica o parámetro que deparó la puntuación más baja fue la completud, es decir, la existencia de datos suficientes para aportar al modelo toda la información requerida para que este funcione bien. Se trata de una característica importante, pues un conjunto incompleto de datos podría llevar a extraer conclusiones erróneas de los estudios de modelización. Por ello, para reducir la incertidumbre a la hora de calcular la probabilidad de que en cierto lugar surjan brotes de enfermedades infecciosas emergentes y de determinar, dentro de la cadena de materialización del riesgo, aquellos eslabones en los que cabe adoptar medidas preventivas, es indispensable disponer de datos de buena calidad.

Effects of naturally acquired gastrointestinal nematode infection on bovine viral diarrhea virus vaccine-directed antibody response in western Canadian feedlot cattle.

Objective: To determine how gastrointestinal nematode (GIN) infection, reflected by fecal egg counts and Ostertagia ostertagi serum antibody titers, is associated with the antibody response to bovine viral diarrhea virus type 1 (BVDV-1) vaccine antigen in fall-weaned feedlot cattle from western Canada. Animals: Cross-sectional study with 240 steer calves derived from an auction market. Procedure: At feedlot arrival, calves were given a commercial vaccine containing modified live BVDV-1. Serum neutralization antibody titers against BVDV-1 antigens were determined in individual blood samples collected pre-vaccination and 21 d after vaccination. A modified Wisconsin sugar floatation method was used to obtain individual calf GIN egg counts in fecal samples on arrival. Antibody titers against O. ostertagi were determined using an enzyme-linked immunosorbent assay in on-arrival blood samples. Results: Fecal egg counts and O. ostertagi titers were not associated with vaccine antibody-fold changes. Similarly, fecal egg counts and O. ostertagi titers were not associated with vaccine-induced seroconversion. Conclusions: The relatively low GIN burdens, reflected by the overall low fecal egg counts in these fall-weaned feedlot calves, did not have measurable adverse effects on the humoral immune response to BVDV-1 vaccine antigens. Clinical relevance: An adequate response to vaccination is important for cattle welfare and productivity. Conditions that negatively affect this response may vary regionally, such as GIN infection. Understanding this is essential. Although subclinical intestinal parasitism did not noticeably affect the antibody response in these steers, higher GIN burdens and actual immune protection from clinical disease remain to be investigated.

Effets d'une infection par des nématodes gastro-intestinaux d'origine naturelle sur la réponse en anticorps dirigés par le vaccin contre le virus de la diarrhée virale bovine chez les bovins des parcs d'engraissement de l'Ouest canadien. Objectif: Déterminer comment l'infection par les nématodes gastro-intestinaux (GIN), reflétée par le nombre d'oeufs fécaux et les titres d'anticorps sériques d'Ostertagia ostertagi, est associée à la réponse en anticorps à l'antigène du vaccin contre le virus de la diarrhée virale bovine de type 1 (BVDV-1) chez les bovins en parc d'engraissement sevrés à l'automne de l'Ouest canadien. Animaux: Étude transversale auprès de 240 veaux bouvillons issus d'un marché aux enchères. Procédure: À leur arrivée au parc d'engraissement, les veaux ont reçu un vaccin commercial contenant du BVDV-1 vivant modifié. Les titres d'anticorps sériques neutralisants contre les antigènes BVDV-1 ont été déterminés dans des échantillons de sang individuels prélevés avant la vaccination et 21 jours après la vaccination. Une méthode de Wisconsin modifiée de flottation au sucre a été utilisée pour obtenir le nombre d'oeufs GIN de chaque veau dans les échantillons fécaux à l'arrivée. Les titres d'anticorps dirigés contre O. ostertagi ont été déterminés à l'aide d'un dosage immuno-enzymatique dans des échantillons de sang à l'arrivée. Résultats: Le nombre d'oeufs fécaux et les titres d'O. ostertagi n'étaient pas associés aux modifications du titre d'anticorps vaccinaux. De même, le nombre d'oeufs fécaux et les titres d'O. ostertagi n'étaient pas associés à la séroconversion induite par le vaccin. Conclusion: Les charges relativement faibles de GIN, reflétées par le faible nombre global d'oeufs fécaux chez ces veaux d'engraissement sevrés à l'automne, n'ont pas eu d'effets indésirables mesurables sur la réponse immunitaire humorale aux antigènes du vaccin BVDV-1. Pertinence clinique: Une réponse adéquate à la vaccination est importante pour le bien-être et la productivité des bovins. Les conditions qui affectent négativement cette réponse peuvent varier selon les régions, telles que l'infection par les GIN. Comprendre cela est essentiel. Bien que le parasitisme intestinal subclinique n'ait pas sensiblement affecté la réponse en anticorps chez ces bouvillons, des charges de GIN plus élevées et une protection immunitaire réelle contre la maladie clinique restent à étudier.(Traduit par Dr Serge Messier).

Bovine leukosis virus, bovine viral diarrhea, and bovine neosporosis seroprevalence in specialized dairy herds in Antioquia-Colombia.

Enzootic bovine leukosis (EBL) is a chronic infectious disease caused by the bovine leukosis virus (BLV), a Deltaretrovirus. Bovine viral diarrhea (BVD) is an infectious disease caused by a pestivirus. Bovine neosporosis is caused by the obligate intracellular parasite Neospora caninum (Nc). These pathogens can have horizontal (postnatal) or vertical (transplacental) transmissions and affect the productive and reproductive performance of infected bovines. This work aimed to detect BLV, BVD, and Nc seroprevalence in specialized dairy cattle from the north, east, and Aburrá Valley regions of the Department of Antioquia, the highest in milk production regions in Antioquia. A total of 599 blood samples, obtained from 53 specialized dairy cattle herds, were evaluated by the ELISA test. The results revealed a seroprevalence of 41.13% for BLV (242/599), 28.48% (163/599) for Nc, and 22.7% (132/599) for BVD. Regarding the regional seroprevalence evaluation, BLV was found in 47.02% of the samples from the east, 36.87% from the north, and 46.02% from the Aburrá Valley. Nc was found in 31.03% of the samples from the east, 24.26% from the north, and 36.63% from Aburrá Valley. BVD was found in 21.62% of the samples from the east, 25.03% from the north region, and 10.39% of the samples from the Aburrá Valley. It is highlighted by these results that the north region, with the highest milk production in Antioquia, had the lowest BLV and Nc seroprevalences but the highest seroprevalence of BVD. BLV has increased in Antioquia in recent years, and as an immunosuppressive infection, opportunities for other pathogens are created by it. A significant statistical difference was found in the average prevalence of the pathogens according to the municipality, cattle breed, and region of origin of the sample. The seroprevalence of these pathogens in specialized dairy herds in Antioquia can be classified as medium-low. However, it is recommended that biosecurity practices should be maximized to avoid the spread of these pathogens due to the variability detected in the region, municipality, breed group, and herd age. The rapid and efficient diagnosis of these three pathogens through reliable methodologies will allow for the control of dissemination in dairy herds.

Genetic polymorphism in European and African sheep breeds reared in Hungary based on 48 SNPs associated with resistance to gastrointestinal parasite infection using KASP-PCR technique.

This pilot study used an alternative and economically efficient technique, the Kompetitive Allele-Specific Polymerase Chain Reaction (KASP-PCR) to examine 48 SNPs from 11 parasite-resistance genes found on 8 chromosomes in 110 animals from five sheep breeds reared in Hungary; Hungarian Tsigai, White Dorper, Dorper, Ile de France, and Hungarian Merino. Allele and genotype frequencies, fixation index, observed heterozygosity, expected heterozygosity, F statistic, and their relationship with the Hardy-Weinberg equilibrium (WHE) and the polymorphic information content (PIC) were determined, followed by principal component analysis (PCA). As much as 32 SNPs out of the 48 initially studied were successfully genotyped. A total of 9 SNPs, 4 SNPs in TLR5, 1 SNP in TLR8, and 4 SNPs in TLR2 genes, were polymorphic. The variable genotype and allele frequency of the TLRs gene indicated genetic variability among the studied sheep breeds, with the Hungarian Merino exhibiting the most polymorphisms, while Dorper was the population with the most SNPs departing from the HWE. According to the PIC value, the rs430457884-TLR2, rs55631273-TLR2, and rs416833129-TLR5 were found to be informative in detecting polymorphisms among individuals within the populations, whereas the rs429546187-TLR5 and rs424975389-TLR5 were found to have a significant influence in clustering the population studied. This study reported a moderate level of genetic variability and that a low to moderate within-breed diversity was maintained in the studied populations.

Infectious diseases in free-range compared to conventional poultry production.

Commercial chicken production for the supply of meat and eggs has expanded in the scale and variety of production systems in use to facilitate the supply of a range of cost-effective products in response to consumer demand. In the egg sector, traditional cage systems were required to be replaced in the EU by 2012, and most of this production capacity has been replaced by colony cage systems, which provide more space, perching, and environmental enrichment. In some countries there is significant production of "cage-free" or "barn" eggs in which the birds remain housed, but have access to litter. In the UK most egg production is now free-range. Meat poultry is produced in "barn" systems with various enrichments and some free-range. The rise in free-range production has seen the return of some diseases. Biosecurity is a critical tool for disease control in all production systems, particularly when disease challenge is high or farms are in a high poultry density area. An infectious dose of a pathogen is important in determining outcomes in terms of health and productivity, so biosecurity, hygiene, and good management are important across many diseases. Infections which are notifiable, of zoonotic importance and those which are sporadic or endemic in commercial poultry production are reviewed. General principles of preventative medicine applicable to the control of infectious diseases in different poultry production systems are proposed in areas such as biosecurity, system design and maintenance, range, and vaccination, though good management is always important.

Can breeders prevent pathogen adaptation when selecting for increased resistance to infectious diseases?

BACKGROUND: Recent research shows that genetic selection has high potential to reduce the prevalence of infectious diseases in livestock. However, like all interventions that target infectious diseases, genetic selection of livestock can exert selection pressure on pathogen populations. Such selection on the pathogen may lead to escape strategies and reduce the effect of selection of livestock for disease resistance. Thus, to successfully breed livestock for lower disease prevalence, it is essential to develop strategies that prevent the invasion of pathogen mutants that escape host resistance. Here we investigate the conditions under which such "escape mutants" can replace wild-type pathogens in a closed livestock population using a mathematical model of disease transmission. RESULTS: Assuming a single gene that confers sufficient resistance, results show that genetic selection for resistance in livestock typically leads to an "invasion window" within which an escape mutant of the pathogen can invade. The bounds of the invasion window are determined by the frequency of resistant hosts in the population. The lower bound occurs when the escape mutant has an advantage over the wild-type pathogen in the population. The upper bound occurs when local eradication of the pathogen is expected. The invasion window is smallest when host resistance is strong and when infection with the wild-type pathogen provides cross immunity to infection with the escape mutant. CONCLUSIONS: To minimise opportunities for pathogens to adapt, under the assumptions of our model, the aim of disease control through genetic selection should be to achieve herd-level eradication of the infection faster than the rate of emergence of escape mutants of the pathogen. Especially for microparasitic infections, this could be achieved by placing animals into herds according to their genetic resistance, such that these herds stay completely out of the invasion window. In contrast to classical breeding theory, our model suggests that multi-trait selection with gradual improvement of each trait of the breeding goal might not be the best strategy when resistance to infectious disease is part of the breeding goal. Temporally, combining genetic selection with other interventions helps to make the invasion window smaller, and thereby reduces the risk of invasion of escape mutants.

Effectiveness and profitability of preventive veterinary interventions in controlling infectious diseases of ruminant livestock in sub-Saharan Africa: a scoping review.

Agriculture in general, and livestock production in particular, serve as a livelihood source for many people in sub-Saharan Africa (SSA). In many settings, lack of control of infectious diseases hampers livestock productivity, undermining the livelihood of rural populations. This scoping review sought to identify veterinary interventions previously evaluated as well as their relative effectiveness in controlling infectious livestock diseases. To be included, papers had to be written in English, German or French, and had to describe the effectiveness and/or profitability of preventive veterinary intervention(s) against anthrax, blackleg, bovine tuberculosis, brucellosis, contagious bovine pleuropneumonia, contagious caprine pleuropneumonia, foot-and-mouth disease, goat pox, lumpy skin disease, pasteurellosis, peste des petits ruminants, and/or sheep pox in any SSA country. Of the 2748 publications initially screened, 84 met our inclusion criteria and were analyzed. Most of the studies (n = 73, 87%) evaluated the effectiveness and/or profitability of vaccination, applied exclusively, applied jointly with, or compared to strategies like deworming, antimicrobial treatment, surveillance, feed supplementation, culling and dipping in reducing morbidity and/or mortality to livestock diseases. The effectiveness and/or profitability of antimicrobial treatment (n = 5), test and slaughter (n = 5), and use of lay animal health workers (n = 1) applied exclusively, were evaluated in the other studies. Vaccination was largely found to be both effective and with positive return on investment. Ineffective vaccination was mainly due to loss of vaccine potency under unfavorable field conditions like adverse weather events, cold chain failure, and mismatch of circulating pathogen strain and the vaccines in use.In summary, vaccination is the most effective and profitable means of controlling infectious livestock diseases in SSA. However, to achieve effective control of these diseases, its implementation must integrate pathogen surveillance, and optimal vaccine delivery tools, to overcome the reported field challenges.

Population structure, intergroup interaction, and human contact govern infectious disease impacts in mountain gorilla populations.

Infectious zoonotic diseases are a threat to wildlife conservation and global health. They are especially a concern for wild apes, which are vulnerable to many human infectious diseases. As ecotourism, deforestation, and great ape field research increase, the threat of human-sourced infections to wild populations becomes more substantial and could result in devastating population declines. The endangered mountain gorillas (Gorilla beringei beringei) of the Virunga Massif in east-central Africa suffer periodic disease outbreaks and are exposed to infections from human-sourced pathogens. It is important to understand the possible risks of disease introduction and spread in this population and how human contact may facilitate disease transmission. Here we present and evaluate an individual-based, stochastic, discrete-time disease transmission model to predict epidemic outcomes and better understand health risks to the Virunga mountain gorilla population. To model disease transmission we have derived estimates for gorilla contact, interaction, and migration rates. The model shows that the social structure of gorilla populations plays a profound role in governing disease impacts with subdivided populations experiencing less than 25% of the outbreak levels of a single homogeneous population. It predicts that gorilla group dispersal and limited group interactions are strong factors in preventing widespread population-level outbreaks of infectious disease after such diseases have been introduced into the population. However, even a moderate amount of human contact increases disease spread and can lead to population-level outbreaks.