Epidemiology and Pathology Laboratory

Puerto Ayora, Ecuador

Epidemiology and Pathology Laboratory

Puerto Ayora, Ecuador
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Eastwood G.,UK Institute of Zoology | Eastwood G.,Epidemiology and Pathology Laboratory | Eastwood G.,University of Leeds | Goodman S.J.,Epidemiology and Pathology Laboratory | And 6 more authors.
EcoHealth | Year: 2014

Infectious disease emergence represents a global threat to human, agricultural animal and wildlife health. West Nile virus (WNV) first emerged in the Americas in 1999 following its introduction to New York from the Old World. This flavivirus rapidly spread across much of North America, causing human, equine and avian mortalities and population declines of multiple wild bird species. It has now spread to Central and South America, and there is concern that the virus will reach the Galápagos Islands, a UNESCO World Heritage Site famous for its unique biodiversity, with potentially catastrophic results. Here, we use wild bird surveillance to examine the current WNV status in the Galapagos Islands and around the Ecuadorian city of Guayaquil (the main air and sea port serving Galápagos). We conducted serosurveys of wild birds on three Galápagos Islands (Baltra, San Cristobal and Santa Cruz) with direct transport links to the South American continent. In addition, dead birds killed by car collisions on Santa Cruz were tested for WNV infection. On mainland Ecuador, serosurveys of wild birds were conducted at three sites around Guayaquil. No evidence of WNV seropositivity or infection was detected. Although wider testing is recommended on the mainland, the study highlights a limit of WNV spread within South America. Our results indicate the continued absence of WNV on Galápagos and suggest the current likelihood of human-mediated transport of WNV to Galápagos to be low. The risk of emergence will almost certainly increase over time, however, and stringent biosecurity and surveillance measures should be put in place to minimise the risk of the introduction of WNV (and other alien pathogens) to Galápagos. © 2014 International Association for Ecology and Health.

Brock P.M.,UK Institute of Zoology | Brock P.M.,University of Leeds | Hall A.J.,University of St. Andrews | Goodman S.J.,University of Leeds | And 3 more authors.
PLoS ONE | Year: 2013

Within individuals, immunity may compete with other life history traits for resources, such as energy and protein, and the damage caused by immunopathology can sometimes outweigh the protective benefits that immune responses confer. However, our understanding of the costs of immunity in the wild and how they relate to the myriad energetic demands on free-ranging organisms is limited. The endangered Galapagos sea lion (Zalophus wollebaeki) is threatened simultaneously by disease from domestic animals and rapid changes in food availability driven by unpredictable environmental variation. We made use of this unique ecology to investigate the relationship between changes in immune activity and changes in body condition. We found that during the first three months of life, changes in antibody concentration were negatively correlated with changes in mass per unit length, skinfold thickness and serum albumin concentration, but only in a sea lion colony exposed to anthropogenic environmental impacts. It has previously been shown that changes in antibody concentration during early Galapagos sea lion development were higher in a colony exposed to anthropogenic environmental impacts than in a control colony. This study allows for the possibility that these relatively large changes in antibody concentration are associated with negative impacts on fitness through an effect on body condition. Our findings suggest that energy availability and the degree of plasticity in immune investment may influence disease risk in natural populations synergistically, through a trade-off between investment in immunity and resistance to starvation. The relative benefits of such investments may change quickly and unpredictably, which allows for the possibility that individuals fine-tune their investment strategies in response to changes in environmental conditions. In addition, our results suggest that anthropogenic environmental impacts may impose subtle energetic costs on individuals, which could contribute to population declines, especially in times of energy shortage. © 2013 Brock et al.

Deem S.L.,WildCare Institute | Deem S.L.,Charles Darwin Foundation | Deem S.L.,University of Missouri-St. Louis | Cruz M.B.,Epidemiology and Pathology Laboratory | And 4 more authors.
Animal Conservation | Year: 2012

Reintroductions are increasingly utilized for the conservation of endangered avian species. To avert disease-related failures, studies to determine disease risks should be performed prior to the implementation of any avian reintroduction program. The presence, and prevalence, of disease-causing agents in both the source population and in birds at the site of reintroduction may help better direct reintroduction programs. In this study, we determined the prevalence of parasitic and pathogenic agents in chickens and wild birds on Floreana Island prior to the reintroduction of the critically endangered Floreana mockingbird Mimus trifasciatus. We investigated avian diseases on Floreana in 175 chickens and 274 wild birds. In addition to a number of clinical abnormalities, chickens tested positive for antibodies to paramyxovirus-1 (30%), adenovirus (11.3%) and seven other pathogens of concern for both domestic and wild birds. Wild birds on Floreana had antibodies to paramyxovirus-1 (3.0%) and adenovirus (2.4%). This is the first report of possible spillover of disease from domestic to wild birds in the archipelago. Based on these findings, and the lack of disease exposure documented in the source mockingbird population, we recommend improved poultry biosecurity measures on Floreana, and that mockingbirds only be reintroduced in areas on the island far from poultry and human presence and following further prerelease analyses. This study provides valuable data for the reintroduction of this iconic bird species and serves as a template for other avian reintroduction programs. © 2011 The Authors. Animal Conservation © 2011 The Zoological Society of London.

Bataille A.,University of Leeds | Bataille A.,UK Institute of Zoology | Bataille A.,University of Sheffield | Bataille A.,Epidemiology and Pathology Laboratory | And 8 more authors.
Molecular Ecology | Year: 2010

Characterization of the fine-scale population dynamics of the mosquito Aedes taeniorhynchus is needed to improve our understanding of its role as a disease vector in the Galapagos Islands. We used microsatellite data to assess the genetic structure of coastal and highland mosquito populations and patterns of gene flow between the two habitats through time on Santa Cruz Island. In addition, we assessed possible associations of mosquito abundance and genetic diversity with environmental variables. The coastal and highland mosquito populations were highly differentiated from each other all year round, with some gene flow detected only during periods of increased precipitation. The results support the hypothesis that selection arising from ecological differences between habitats is driving adaptation and divergence in A. taeniorhynchus, and maintaining long-term genetic differentiation of the populations against gene flow. The highland and lowland populations may constitute an example of incipient speciation in progress. Highland populations were characterized by lower observed heterozygosity and allelic richness, suggesting a founder effect and/or lower breeding site availability in the highlands. A lack of reduction in genetic diversity over time in highland populations suggests that they survive dry periods as dormant eggs. Association between mosquito abundance and precipitation was strong in the highlands, whereas tide height was the main factor affecting mosquito abundance on the coast. Our findings suggests differences in the infection dynamics of mosquito-borne parasites in the highlands compared to the coast, and a higher risk of mosquito-driven disease spread across these habitats during periods of increased precipitation. © 2010 Blackwell Publishing Ltd.

Bataille A.,University of Leeds | Bataille A.,UK Institute of Zoology | Bataille A.,University of Sheffield | Bataille A.,Epidemiology and Pathology Laboratory | And 6 more authors.
Infection, Genetics and Evolution | Year: 2011

The black salt-marsh mosquito (Aedes taeniorhynchus) is the only native mosquito in the Galapagos Islands and potentially a major disease vector for Galapagos wildlife. Little is known about its population structure, or how its dynamics may be influenced by human presence in the archipelago. We used microsatellite data to assess the structure and patterns of A. taeniorhynchus gene flow among and within islands, to identify potential barriers to mosquito dispersal, and to investigate human-aided transport of mosquitoes across the archipelago. Our results show that inter-island migration of A. taeniorhynchus occurs frequently on an isolation by distance basis. High levels of inter-island migration were detected amongst the major ports of the archipelago, strongly suggesting the occurrence of human-aided transport of mosquitoes among islands, underlining the need for strict control measures to avoid the transport of disease vectors between islands. The prevalence of filarial nematode infection in Galapagos flightless cormorants is correlated with the population structure and migration patterns of A. taeniorhynchus, suggesting that A. taeniorhynchus is an important vector of this arthropod-borne parasite in the Galapagos Islands. Therefore mosquito population structure in Galapagos may have the potential to influence mosquito-borne parasite population dynamics, and the subsequent impacts of such pathogens on their host species in the islands. © 2011 Elsevier B.V.

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