Culicoides species communities associated with wild ruminant ecosystems in Spain: Tracking the way to determine potential bridge vectors for arboviruses

This is an open access article distributed under the terms of the Creative Commons Attribution License.-- et al.The genus Culicoides Latreille 1809 is a well-known vector for protozoa, filarial worms and, above all, numerous viruses. The Bluetongue virus (BTV) and the recently emerged Schmallenberg virus (SBV) are responsible for important infectious, non-contagious, insect-borne viral diseases found in domestic ruminants and transmitted by Culicoides spp. Both of these diseases have been detected in wild ruminants, but their role as reservoirs during the vector-free season still remains relatively unknown. In fact, we tend to ignore the possibility of wild ruminants acting as a source of disease (BTV, SBV) and permitting its reintroduction to domestic ruminants during the following vector season. In this context, a knowledge of the composition of the Culicoides species communities that inhabit areas where there are wild ruminants is of major importance as the presence of a vector species is a prerequisite for disease transmission. In this study, samplings were conducted in areas inhabited by different wild ruminant species; samples were taken in both 2009 and 2010, on a monthly basis, during the peak season for midge activity (in summer and autumn). A total of 102,693 specimens of 40 different species of the genus Culicoides were trapped; these included major BTV and SBV vector species. The most abundant vector species were C. imicola and species of the Obsoletus group, which represented 15% and 11% of total numbers of specimens, respectively. At the local scale, the presence of major BTV and SBV vector species in areas with wild ruminants coincided with that of the nearest sentinel farms included in the Spanish Bluetongue Entomological Surveillance Programme, although their relative abundance varied. The data suggest that such species do not exhibit strong host specificity towards either domestic or wild ruminants and that they could consequently play a prominent role as bridge vectors for different pathogens between both types of ruminants. This finding would support the hypothesis that wild ruminants could act as reservoirs for such pathogens, and subsequently be involved in the reintroduction of disease to livestock on neighbouring farms.This study was supported by the project FAU 2008-0019 from Instituto Nacional de Investigaciones Agrarias, and was partially funded by EU grant GOCE-2003-010284 EDENext and is cataloged by the EDENext Steering Committee as EDENext429 (http://www.edenext.eu). F. Ruiz-Fons is supported by the Spanish Ministry for the Economy and Competitiveness through a Juan de la Cierva postdoctoral contract.Peer Reviewe

Serosurvey for selected pathogens in Iberian roe deer

<p>Abstract</p> <p>Background</p> <p>The roe deer is the most abundant and widespread wild Eurasian cervid. Its populations are expanding and increasingly in contact with livestock. This may affect the distribution of infectious diseases shared with other wild and domestic ungulates.</p> <p>Methods</p> <p>We investigated the antibody seroprevalence against Pestivirus, Herpesvirus, Bluetongue (BT) virus, <it>M. avium paratuberculosis </it>(MAP), and <it>Brucella </it>sp. in 519 roe deer from different regions in Spain, south-western Europe.</p> <p>Results</p> <p>No antibodies were detected against BT and <it>Brucella </it>sp. However, antibodies were detected against Pestivirus (1.5%), Herpesvirus (0.2%) and MAP (9.2%). MAP antibodies were detected in seven of the eight populations (range 5-16.4%).</p> <p>Conclusions</p> <p>The detection of MAP antibodies in samples from most roe deer populations suggests that contact with MAP is widespread in this wildlife species. The highest prevalence was detected in sites with abundant dairy cattle and frequent use of liquid manure on pastures. Considering the results obtained regarding exposure to different pathogens, we suggest that antibody prevalences in this non-gregarious browser are largely determined by environmental factors, potentially modulating vector populations or pathogen survival in the environment.</p

Phenotypic Characterization of Encephalitis in the BRAINS of Badgers Naturally Infected with Canine Distemper Virus

[EN] Canine distemper virus (CDV) affects a huge diversity of domestic and wild carnivores, with increasing numbers of mortality events worldwide. The local cell-mediated immune response elicited against a natural infection is an important factor in determining the outcome of CDV infection. Therefore, the purposes of this study were to describe the local immune response within the central nervous systems (CNSs) of seven badgers naturally infected with CDV in Asturias (Atlantic Spain) and to determine the phenotype and distribution of microglial cells, T and B lymphocytes, and astrocytes in the foci of gliosis located in the thalamus and cerebellum using immunohistochemistry. The immunohistochemical assessment demonstrated the presence of Iba1-positive microglia and GFAP-positive astrocytes in the foci of gliosis, whereas T (CD3-negative) or B (CD20-negative) lymphocytes in those same lesions were absent. Our results also revealed that the badgers with natural CDV encephalitis presented lesions mostly located in the white matter of the thalamus and cerebellum, suggesting a CDV-specific tropism for the white matter of badger brains in those locations. The knowledge gained in the field of the immunopathogenesis of distemper disease affecting the CNSs of badgers could help to clarify CDV disease patterns in this speciesSIThis work was partially funded by the Principality of Asturias (PCTI 2021–2023, GRUPIN: IDI-2021-000102) and European Regional Development Fun

Long-Term Dynamics of Bluetongue Virus in Wild Ruminants : relationship with Outbreaks in Livestock in Spain, 2006-2011

Wild and domestic ruminants are susceptible to Bluetongue virus (BTV) infection. Three BTV serotypes (BTV-4, BTV-1 and BTV-8) have been detected in Spain in the last decade. Even though control strategies have been applied to livestock, BTV circulation has been frequently detected in wild ruminant populations in Spain. The aim of the present study is to assess the role for wild ruminants in maintaining BTV after the vaccination programs in livestock in mainland Spain. A total of 931 out 1,914 (48.6%) serum samples, collected from eight different wild ruminant species between 2006 and 2011, were BTV positive by ELISA. In order to detect specific antibodies against BTV-1, BTV-4 and BTV-8, positive sera were also tested by serumneutralisation test (SNT). From the ELISA positive samples that could be tested by SNT (687 out of 931), 292 (42.5%) showed neutralising antibodies against one or two BTV serotypes. For each BTV seroptype, the number of outbreaks in livestock (11,857 outbreaks in total) was modelled with pure autoregressive models and the resulting smoothed values, representing the predicted number of BTV outbreaks in livestock at municipality level, were positively correlated with BTV persistence in wild species. The strength of this relationship significantly decreased as red deer (Cervus elaphus) population abundance increased. In addition, BTV RNA was detected by real time RT-PCR in 32 out of 311 (10.3%) spleen samples from seropositive animals. Although BT outbreaks in livestock have decreased substantially after vaccination campaigns, our results indicated that wild ruminants have been exposed to BTV in territories where outbreaks in domestic animals occurred. The detection of BTV RNA and spatial association between BT outbreaks in livestock and BTV rates in red deer are consistent with the hypothesis of virus circulation and BTV maintenance within Iberian wild ruminant populations

Immunohistochemical Assessment of Immune Response in the Dermis of Sarcoptes scabiei—Infested Wild Carnivores (Wolf and Fox) and Ruminants (Chamois and Red Deer)

© 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/)[EN] Sarcoptic mange is caused by the mite Sarcoptes scabiei and has been described in several species of domestic and wild mammals. Macroscopic lesions are predominantly hyperkeratotic (type I hypersensitivity) in fox, chamois and deer, but alopecic (type IV hypersensitivity) in wolf and some fox populations. To begin to understand the immune processes underlying these species differences in lesions, we examined skin biopsies from wolves (Canis lupus), foxes (Vulpes vulpes), chamois (Rupicapra rupicapra) and red deer (Cervus elaphus) naturally infested with S. scabiei. Twenty skin samples from five animals per species were used. Sections were immuno-stained with primary antibodies against Iba1 to detect macrophages, lambda chain to detect plasma cells, CD3 to detect T lymphocytes and CD20 to detect B lymphocytes. Skin lesions contained significantly more inflammatory cells in the fox than in the wolf and chamois. Macrophages were the most abundant inflammatory cells in the lesions of all the species studied, suggesting a predominantly innate, non-specific immune response. Lesions from the wolf contained higher proportions of macrophages than the other species, which may reflect a more effective response, leading to alopecic lesions. In red deer, macrophages were significantly more abundant than plasma cells, T lymphocytes and B lymphocytes, which were similarly abundant. The fox proportion of plasma cells was significantly higher than those of T and B lymphocytes. In chamois, T lymphocytes were more abundant than B lymphocytes and plasma cells, although the differences were significant only in the case of macrophages. These results suggest that all the species examined mount a predominantly innate immune response against S. scabiei infestation, while fox and chamois may also mount substantial humoral and cellular immune responses, respectively, with apparently scarce effectiveness that lead to hyperkeratotic lesions.SIThe authors would like to thank the Vice-Ministry of the Environment of the Principado of Asturias. The authors thank A. Chapin Rodríguez for critically reviewing the manuscript.This work was partially supported by the Principado de Asturias, PCTI 2018–220 (GRUPIN: IDI2018-000237 and FEDER). Ms. Ileana Z. Martínez was supported by a Fundación Carolina PhD scholarship (2017 call)

Canine distemper virus in wildlife in south‐western Europe

[EN] Multi-host pathogens emerging and re-emerging at the wildlife–domestic animal interface affect wildlife management and conservation. This is the case of canine distemper virus (CDV), a paramyxovirus closely related to human measles virus and rinderpest virus of cattle. With an area of 10,603 km2, Asturias region in Atlantic Spain is a hotspot of carnivore diversity, which includes the largest Eurasian brown bear (Ursus arctos arctos) population and one of the largest wolf (Canis lupus) populations in south-western Europe. In 2020–2021, we recorded mortality due to distemper in four carnivore species including three mustelids (Eurasian badger Meles meles, European marten Martes martes and European polecat Mustela putorius) and one canid (red fox, Vulpes vulpes). Clinical signs and pathology were similar across species and consistent with the emergence of a highly pathogenic viral strain, with CDV antigen mainly located in the central nervous system, lungs, spleen and lymph nodes. A molecular study in eight wild carnivore species, also including the Iberian wolf, Eurasian brown bear, American mink (Neovison vison) and stone marten (Martes foina), revealed 19.51% (16/82) of positivity. Phylogenetic analysis demonstrated that CDV belonged to the previously described European lineage. A retrospective serosurvey (2008–2020) showed a high seroprevalence of CDV antibodies (43.4%) in 684 analyzed badgers, indicating a long-term though not stable viral circulation in this multi-host community. The possible triggers of the 2020–2021 outbreak and the implications for carnivore management and conservation are discussed.SISpanishMinisterio de Ciencia; Innovación y Universidades (MCIU); The Agencia Estatal de Investigación (AEI); FEDER co-funded: RTI2018-096010-B-C2

Canine adenovirus type 1 (CAdV-1) in free-ranging European brown bear (Ursus arctos arctos): A threat for Cantabrian population?

[EN] Canine adenovirus type 1 (CAdV-1) is responsible for infectious canine hepatitis. The disease has been described in captive American black bear (Ursus americanus) and European brown bear (Ursus arctos arctos), with just one recently reported case in a cub of a free-ranging brown bear (Ursus arctos horribilis) from Alaska. The aim of this work is to summarize findings related to presence and associated mortality of CAdV-1 in 21 free-ranging Cantabrian brown bears (Ursus arctos arctos) submitted to necropsy in Asturias and Castilla y León (northwestern Spain) from 1998 to 2018. On the basis of the anatomopathological findings and laboratory results three free-ranging brown bears died due to infectious canine hepatitis, which is to our knowledge the first description of death due to this disease in free-ranging bears in Europe. Gross lesions consisted of petechial haemorrhages and congestion in different internal organs, haemorrhagic fluid in internal cavities, friable and yellowish liver and thickening of gall bladder. Microscopic lesions were observed mainly in liver, kidney and brain and consisted of multifocal necrosis of cells with presence of basophilic intranuclear inclusions. Immunohistochemical (IHC) and real-time polymerase chain reaction (qPCR) techniques were used to assess the presence of CAdV-1 in paraffin-embedded liver samples. Viral antigens were detected by IHC labelling within hepatocytes and Küppfer cells in the three animals. The presence of viral DNA was confirmed by qPCR in one of them. In order to evaluate the circulation of CAdV-1 in brown bears, a retrospective study was performed using both IHC and qPCR techniques in 11 and 12 additional brown bears, respectively. An extra brown bear was found positive by IHC. This study shows that CAdV-1 surveillance of brown bears and sympatric carnivores should be considered as major concern for the monitoring the population evolution throughout time in this endangered species.SIAuthors thank colleagues from SERIDA (A. Espí, J. M. Prieto and R.A. Juste), University of León (C. Pérez Martínez and M. J. GarcíaIglesias), Servicio de Espacios Protegidos y Conservación de la Natu-raleza, Dirección General de Biodiversidad from Viceconsejería deMedio Ambiente del Principado de Asturias (L. M. Álvarez) and Con-sejería de Fomento y Medio Ambiente de la Junta de Castilla y Léonfor the invaluable collaboration. Authors also thank Andrea Balboni(Dipartimento di Scienze Mediche Veterinarie, Università di Bologna)for providing CAdV‐1 DNA sample. We thank Donal Savage for criti-cally reviewing the manuscrip

Cardiopulmonary nematode infections in wild canids: Does the key lie on host-prey-parasite evolution?

©2019. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/ This document is the Accepted, version of a Published Work that appeared in final form in Research in Veterinary Science. To access the final edited and published work see https://doi.org/10.1016/j.rvsc.2019.08.008Cardiopulmonary nematodes are among the most pathogenic parasites of domestic and wild canids. The aim of this study was to describe the species diversity, prevalence and infection intensity of these parasites in the Iberian wolf (Canis lupus signatus) and the red fox (Vulpes vulpes) in the northwest of the Iberian Peninsula. 257 foxes and 74 wolves were necropsied between 2008 and 2014. Four nematode species were identified: Angiostrongylus vasorum, Eucoleus aerophilus, Crenosoma vulpis and Filaroides hirthi. This last species was only found in wolves, being the first time that is cited worldwide in this wild canid. The overall parasite prevalence was significantly higher in foxes (70%) than in wolves (28%). Specifically, prevalences in foxes and wolves were, respectively, 43% and 22% for A. vasorum, 33% and 5% for E. aerophilus, and 30% and 9% for C. vulpis. The prevalence of F. hirthi was 16%. The A. vasorum intensity was significantly higher in foxes than in wolves. Differences between host species in the risk of infection would be associated to diverging feeding behavior, and possibly reflects a parasite-host adaptation related to host's hunting strategies and cardiorespiratory requirements. This study revealed an association between infection and environmental factors, and highlighted a wide variation in the spatial distribution of A. vasorum. Our results indicate that cardiopulmonary parasites are widespread in wild canids in northwest Spain, and further agrees with other studies indicating the expansion of A. vasorum in Europe and, therefore, the urgent need to investigate infection in dogs in sympatric areas