Long-term avian influenza virus epidemiology in a small Spanish wetland ecosystem is driven by the breeding Anseriformes community

During 2007–2009 and 2012–2014, avian influenza virus (AIV) was studied in a wild avian community of a northern Spanish wetland using non-invasive sampling methods and host identification by COI barcoding. The aim of this longitudinal study was to evaluate AIV dynamics in a natural wetland ecosystem, taking into account both virological aspects and ecological traits of hosts. Global AIV prevalence decreased significantly during the second sampling period (0.3%) compared to the first (6.6%). Circulating subtype distributions were also different between periods, with a noteworthy H5 and H7 subtype richness during the first sampling period. Mallard Anas platyrhynchos was identified as the main AIV host, although not all positive samples could be ascribed to the host. We modelled AIV prevalence with regard to the avian host community composition and meteorological data from the wetland. Statistical analysis revealed seasonal differences in AIV detection, with higher prevalence during the breeding season compared to other phenological events. The model also shows that the lower AIV prevalence during the second study period was associated with a significant reduction of breeding Anseriformes in the wetland, revealing a long-term fluctuation of AIV prevalence driven by the breeding Anseriformes community. This longitudinal study on AIV epidemiology in a natural ecosystem reveals that although prevalence follows seasonal and annual patterns, long-term prevalence fluctuation is linked to the breeding community composition and size. These results are relevant to understanding the influence of host ecology on pathogen transmission for preventing and managing influenza emergence.This study has been funded by the Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA) (RTA2011-00111-C03 Grant) and Departamento de Desarrollo Económico e Infraestructuras del Gobierno Vasco. OT was recipient of an INIA predoctoral grant. PA is supported by Ministerio de Economia, industria y competitividad del Gobierno de España and Universidad de Castilla-La Mancha through “Ramón y Cajal” contract (RYC-2012-11970).Peer reviewe

Ecological factors driving avian influenza virus dynamics in Spanish wetland ecosystems

This is an open-access article distributed under the terms of the Creative Commons Attribution License.-- et al.Studies exploring the ecological interactions between avian influenza viruses (AIV), natural hosts and the environment are scarce. Most work has focused on viral survival and transmission under laboratory conditions and through mathematical modelling. However, more integrated studies performed under field conditions are required to validate these results. In this study, we combined information on bird community, environmental factors and viral epidemiology to assess the contribution of biotic and abiotic factors in the occurrence of low pathogenic AIV in Spanish wetlands. For that purpose, seven locations in five different wetlands were studied during two years (2007-2009), including seven sampling visits by location. In each survey, fresh faeces (n = 4578) of wild birds and water samples were collected for viral detection. Also, the vegetation structure, water physical properties of wetlands, climatic conditions and wild bird community composition were determined. An overall AIV prevalence of 1.7%±0.4 was detected in faecal samples with important fluctuations among seasons and locations. Twenty-six AIV were isolated from the 78 RRT-PCR positive samples and eight different haemagglutinines and five neuraminidases were identified, being the combination H3N8 the most frequent. Variation partitioning procedures identified the combination of space and time variables as the most important pure factor - independently to other factors - explaining the variation in AIV prevalence (36.8%), followed by meteorological factor (21.5%) and wild bird community composition/vegetation structure (21.1%). These results contribute to the understanding of AIV ecological drivers in Spanish ecosystems and provide useful guidelines for AIV risk assessment identifying potential hotspots of AIV activity.This work was financially supported by INIA (Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria), project FAU2006-00019-C03-00 and by Department of Environment, Territorial Planning, Agriculture and Fisheries of the Basque Government. P. Acevedo was supported by a Beatriu de Pinós fellowship funded by Comissionat per a Universitats i Recerca del Departament d'Innovació, Universitats i Empresa, of the Generalitat de Catalunya and the COFUND Programme-Marie Curie Actions under 7th Marc Programme of the European Community.Peer Reviewe

Ecological Factors Driving Avian Influenza Virus Dynamics in Spanish Wetland Ecosystems

Studies exploring the ecological interactions between avian influenza viruses (AIV), natural hosts and the environment are scarce. Most work has focused on viral survival and transmission under laboratory conditions and through mathematical modelling. However, more integrated studies performed under field conditions are required to validate these results. In this study, we combined information on bird community, environmental factors and viral epidemiology to assess the contribution of biotic and abiotic factors in the occurrence of low pathogenic AIV in Spanish wetlands. For that purpose, seven locations in five different wetlands were studied during two years (2007-2009), including seven sampling visits by location. In each survey, fresh faeces (n = 4578) of wild birds and water samples were collected for viral detection. Also, the vegetation structure, water physical properties of wetlands, climatic conditions and wild bird community composition were determined. An overall AIV prevalence of 1.7%±0.4 was detected in faecal samples with important fluctuations among seasons and locations. Twenty-six AIV were isolated from the 78 RRT-PCR positive samples and eight different haemagglutinines and five neuraminidases were identified, being the combination H3N8 the most frequent. Variation partitioning procedures identified the combination of space and time variables as the most important pure factor - independently to other factors - explaining the variation in AIV prevalence (36.8%), followed by meteorological factor (21.5%) and wild bird community composition/vegetation structure (21.1%). These results contribute to the understanding of AIV ecological drivers in Spanish ecosystems and provide useful guidelines for AIV risk assessment identifying potential hotspots of AIV activity

Lack of evidence of paratuberculosis in wild canids from southwestern Europe

This article is made available via the PMC Open Access Subset for unrestricted research re-use and secondary analysis in any form or by any means with acknowledgement of the original source.Wild carnivores are at the top of the trophic chain. They are predators and carrion consumers, and thus, prone to come in contact with disease agents contaminating the environment or infecting live or dead animals. We hypothesized that wild canids could be used as sentinels for the detection of regions with higher Mycobacterium avium paratuberculosis (MAP) prevalence in wild and domestic animals. To test this hypothesis, we set up an ELISA to test 262 wolf (Canis lupus) and fox (Vulpes vulpes) sera for MAP-specific antibodies and processed a subset of samples for culture (n = 61), MAP-specific PCR (15) and histopathology (14). In wolves, the optical density (OD) values in the ELISA were continuously distributed. Ten fox sera (4%) had OD readings of over twice the mean, suggesting contact with mycobacteria. However, all samples tested by PCR were negative for both IS900 and ISMAP02 sequences, and samples cultured for MAP yielded no growth. No visible paratuberculosis or tuberculosis-compatible lesions were recorded. On histopathological examination, no lesions compatible with mycobacterial diseases were observed. These results suggest that wild canids show little or no evidence of paratuberculosis and are unlikely to be useful sentinels for the detection of MAP in Southwestern Europe.This study is a contribution to grant AGL2008-03875 Plan Nacional MCINN and FEDER, European Research Project 212414 “Strategies for the Eradication of Bovine Tuberculosis, Tb-Step”, and the agreements with Ministerio de Medio Ambiente y Medio Rural y Marino, Principado de Asturias, and Castilla–La Mancha. R. Sobrino had a grant from Castilla–La Mancha.Peer reviewe

Detection of low pathogenic avian influenza viruses in wild birds in Castilla-La Mancha (south central Spain)

The Iberian Peninsula is located along the East Atlantic and Black Sea/Mediterranean flyways and is the third ranking European country as wintering quarter for wild migrating birds after Turkey and Rumania. For these reasons, Spanish wetlands are of importance in AIV surveillance, and of great interest for the study of the epidemiology of LPAIV under Mediterranean climate conditions. Nevertheless, information on prevalence of LPAIV viruses in Spain is still scarce and is restricted to two serological surveys carried out in the south of the country during 1990 and 1994 and one virological study performed recently in North East Spain. In the present study we analysed the prevalence of AIV circulating in wild birds in continental wetlands in central Spain and determined temporal, spatial and species variation. Real time RTPCR was performed on 1435 faecal samples and cloacal swabs from 54 species. An overall AIV prevalence of 2.6% was detected with a peak during November and December, when thousands of migrating wild birds arrive to Spain for wintering. Highest prevalence rates were detected in Phoenicopteriformes and Anseriformes. AIV prevalence obtained from cloacal swabs and fresh faeces did not vary significantly, which supports faecal sampling as an appropriate method for large scale LPAIV surveillance programs. Viral culture was achieved in samples obtained from two Mallards and a White stork, in which subtypes H7N9 and H11N9, respectively, were identified. Our results reflect a similar scenario in AIV epidemiology in small continental wetlands as compared to large coastal humid areas in Europe and underline the importance of including species such as flamingos and storks in surveillance programs, since their role in AIV ecology in these areas could be more important than previously considered.We are grateful to all the personnel of the Wildlife Rehabilitation Centres in Castilla-La Mancha for their collaboration and to all the people that helped in the field work. We also thank JCCM for support, Tomás Velasco for sharing his knowledge of wetlands and waterbirds in Central Spain and Vega Álvarez (NEIKER) for technical support. We wish to thank the “Spanish National Reference Laboratory” for official confirmation of isolates. This work is a contribution to grant INIA RTA2005-111-00, grant JCCM PA298-05 and grant MEC/INIA FAU2006-019-C03. E. Pérez-Ramírez currently has an I3p fellowship from the Spanish Science Council (CSIC).Peer Reviewe

Monitoring avian influenza virus in a small Spanish wetland using non-invasive sampling methods

Resumen del trabajo presentado a la Fifth ESWI Influenza Conference, celebrada en Riga (Latvia) del 14 al 17 de septiembre de 2014.Anseriformes and Charadriiformes are known to be the main reservoirs for Avian Influenza Virus (AIV) in which the transmission within these occurs via faecal/oral contact in contaminated water. Understanding the Avian Influenza Virus (AIV) persistence and transmission dynamics is crucial for predicting disease outbreaks and improving surveillance strategies. The aim of this work was to monitor the presence and persistence of AIV in its natural environment in relation to ecology of its reservoir hosts. During a 23 month period (March 2012-January 2014) the relationship between AIV presence and wildfowl population movements was studied in a small wetland in the north of Spain where the presence of different AIV had previously been recorded. This water ecosystem is considered of special interest as it is an important site for wintering and breeding of waterfowl and as a stopover for waterfowl migrating further south, being considerably small (209 Ha) and close to an urbanised area. Fresh faeces were collected monthly from islets scattered along the wetland, used as roosting sites by the birds. Bird censuses and meteorological data were gathered in parallel in order to relate AIV detection to waterfowl ecology. For AIV detection RNA was extracted from the faecal matter and analysed by influenza A specific rRT-PCR. Positive samples were then tested for H5 and H7 subtypes and inoculated into embrionated SPF chicken eggs for virus isolation. During the 23 months, a total of 2096 samples were analysed and AIV was detected in 0.29%. In regard to the wild bird population movements, the highest AIV prevalence occurred along the breeding season (0.67%) and autumn migration (0.35%). The highest prevalence 3.23% was recorded in June 2012. All positive samples contained low pathogenic AIV. The concentration of positive results during the two above mentioned periods may be related to two scenarios in waterfowl ecology; on one hand, high water bird aggregation densities and therefore a greater virus titre input to the environment during migration and fledging of chicks and on the other hand, the presence of a naïve juvenile population with a still less efficient immune system that will make them more susceptible towards an AIV infection. More research is deemed necessary clarify the complex AIV ecology. In this regard, further studies are presently being undertaken.Peer Reviewe

Data from: Long-term avian influenza virus epidemiology in a small Spanish wetland ecosystem is driven by the breeding Anseriformes community

Raw data of the main predictors used, namely the avian community inhabiting Salburua wetland, AIV prevalence and meteorological parameters

Long-term avian influenza virus epidemiology in a small Spanish wetland ecosystem is driven by the breeding Anseriformes community

Abstract During 2007–2009 and 2012–2014, avian influenza virus (AIV) was studied in a wild avian community of a northern Spanish wetland using non-invasive sampling methods and host identification by COI barcoding. The aim of this longitudinal study was to evaluate AIV dynamics in a natural wetland ecosystem, taking into account both virological aspects and ecological traits of hosts. Global AIV prevalence decreased significantly during the second sampling period (0.3%) compared to the first (6.6%). Circulating subtype distributions were also different between periods, with a noteworthy H5 and H7 subtype richness during the first sampling period. Mallard Anas platyrhynchos was identified as the main AIV host, although not all positive samples could be ascribed to the host. We modelled AIV prevalence with regard to the avian host community composition and meteorological data from the wetland. Statistical analysis revealed seasonal differences in AIV detection, with higher prevalence during the breeding season compared to other phenological events. The model also shows that the lower AIV prevalence during the second study period was associated with a significant reduction of breeding Anseriformes in the wetland, revealing a long-term fluctuation of AIV prevalence driven by the breeding Anseriformes community. This longitudinal study on AIV epidemiology in a natural ecosystem reveals that although prevalence follows seasonal and annual patterns, long-term prevalence fluctuation is linked to the breeding community composition and size. These results are relevant to understanding the influence of host ecology on pathogen transmission for preventing and managing influenza emergence

Helminth parasites of the Eurasian badger (Meles meles L.) in the Basque Country (Spain)

The helminthological study of 26 Eurasian badgers (Meles meles L.) in the Basque Country (northern Spain) revealed the presence of two trematode (Euryhelmis squamula and Brachylaima sp.), three cestode (Atriotaenia incisa, Mesocestoides sp. and Taenia sp.) and five nematode (Aonchotheca putorii, Physaloptera sp., Molineus patens, Uncinaria criniformis and Strongyloides sp.) species. All 15 individuals analysed for Trichinella sp. were negative. The coprological analysis (flotation and migration) revealed the excretion of strongylid, capillariid and trematode eggs, and Crenosoma sp. and Angiostrongylus sp. larvae. No sex- or age-related differences were found in the parasite burden or egg and larvae excretion. A. incisa and M. patens abundances were positively correlated, both species being negatively correlated with badger weight. The presence of adults of U. criniformis and strongylid eggs in faeces was not independent. Badgers excreting Angiostrongylus larvae were in poorer condition than those not excreting.This work is a contribution to a project by ‘Departamento de Agricultura y Pesca del Gobierno Vasco’.Peer reviewe

Infectious disease surveillance at the wildlife-domestic interface of a partridge farm

Resumen del trabajo presentado a la Joint Virtual Conference of the WDA and EWDA, celebrada del 31 de agosto al 2 de septiembre de 2021.Peer reviewe