ORCID Profile
0000-0002-3579-7588
Current Organisation
University of Tasmania
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Research Topics
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Veterinary Sciences | Biological Mathematics | Veterinary Microbiology (excl. Virology) | Veterinary Diagnosis and Diagnostics | Veterinary Epidemiology | Infectious Agents | Simulation and Modelling | Veterinary Immunology | Microbiology | Artificial Intelligence and Image Processing |
ANZSRC Socio-Economic Objective (SEO)
Control of Animal Pests, Diseases and Exotic Species in Forest and Woodlands Environments | Sheep - Meat | Ecosystem Adaptation to Climate Change | Flora, Fauna and Biodiversity of environments not elsewhere classified | Control of Animal Pests, Diseases and Exotic Species in Farmland, Arable Cropland and Permanent Cropland Environments | Beef Cattle | Veterinary Diagnostics | Animal Welfare | Expanding Knowledge in the Biological Sciences | Veterinary Biological Preventatives (e.g. Vaccines)
Related Links
Publications
International meeting on sarcoptic mange in wildlife, June 2018, Blacksburg, Virginia, USA
Publisher: Springer Science and Business Media LLC
Date: 03-08-2018
Three Pathogens in Sympatric Populations of Pumas, Bobcats, and Domestic Cats: Implications for Infectious Disease Transmission
Publisher: Public Library of Science (PLoS)
Date: 08-02-2012
Immunization strategies producing a humoral IgG immune response against devil facial tumor disease in the majority of Tasmanian devils destined for wild release
Publisher: Frontiers Media SA
Date: 19-02-2018
Sampling Frequency Differentially Influences Interpretation of Zoonotic Pathogen and Host Dynamics: Sin Nombre Virus and Deer Mice
Publisher: Mary Ann Liebert Inc
Date: 08-2010
Untangling the model muddle: Empirical tumour growth in Tasmanian devil facial tumour disease
Publisher: Springer Science and Business Media LLC
Date: 24-07-2017
DOI: 10.1038/S41598-017-06166-3
Abstract: A pressing and unresolved topic in cancer research is how tumours grow in the absence of treatment. Despite advances in cancer biology, therapeutic and diagnostic technologies, there is limited knowledge regarding the fundamental growth and developmental patterns in solid tumours. In this ten year study, we estimated growth curves in Tasmanian devil facial tumours, a clonal transmissible cancer, in males and females with two different karyotypes (diploid, tetraploid) and facial locations (mucosal, dermal), using established differential equation models and model selection. Logistic growth was the most parsimonious model for diploid, tetraploid and mucosal tumours, with less model certainty for dermal tumours. Estimates of daily proportional tumour growth rate per day (95% Bayesian CIs) varied with ploidy and location [diploid 0.016 (0.014–0.020), tetraploid 0.026 (0.020–0.033), mucosal 0.013 (0.011–0.015), dermal 0.020 (0.016–0.024)]. Final tumour size (cm 3 ) also varied, particularly the upper credible interval owing to host mortality as tumours approached maximum volume [diploid 364 (136–2,475), tetraploid 172 (100–305), dermal 226 (134–471)]. To our knowledge, these are the first empirical estimates of tumour growth in the absence of treatment in a wild population. Through this animal-cancer system our findings may enhance understanding of how tumour properties interact with growth dynamics in other types of cancer.
Genome‐wide expression reveals multiple systemic effects associated with detection of anticoagulant poisons in bobcats (Lynx rufus)
Publisher: Wiley
Date: 03-2018
DOI: 10.1111/MEC.14531
Abstract: Anticoagulant rodenticides (ARs) are indiscriminate toxicants that threaten nontarget predatory and scavenger species through secondary poisoning. Accumulating evidence suggests that AR exposure may have disruptive sublethal consequences on in iduals that can affect fitness. We evaluated AR-related effects on genome-wide expression patterns in a population of bobcats in southern California. We identify differential expression of genes involved in xenobiotic metabolism, endoplasmic reticulum stress response, epithelial integrity and both adaptive and innate immune function. Further, we find that differential expression of immune-related genes may be attributable to AR-related effects on leucocyte differentiation. Collectively, our results provide an unprecedented understanding of the sublethal effects of AR exposure on a wild carnivore. These findings highlight potential detrimental effects of ARs on a wide variety of species worldwide that may consume poisoned rodents and indicate the need to investigate gene expression effects of other toxicants added to natural environments by humans.
The forecasting of dynamical Ross River virus outbreaks: Victoria, Australia
Publisher: Elsevier BV
Date: 03-2020
DOI: 10.1016/J.EPIDEM.2019.100377
Abstract: Ross River virus (RRV) is Australia's most epidemiologically important mosquito-borne disease. During RRV epidemics in the State of Victoria (such as 2010/11 and 2016/17) notifications can account for up to 30% of national RRV notifications. However, little is known about factors which can forecast RRV transmission in Victoria. We aimed to understand factors associated with RRV transmission in epidemiologically important regions of Victoria and establish an early warning forecast system. We developed negative binomial regression models to forecast human RRV notifications across 11 Local Government Areas (LGAs) using climatic, environmental, and oceanographic variables. Data were collected from July 2008 to June 2018. Data from July 2008 to June 2012 were used as a training data set, while July 2012 to June 2018 were used as a testing data set. Evapotranspiration and precipitation were found to be common factors for forecasting RRV notifications across sites. Several site-specific factors were also important in forecasting RRV notifications which varied between LGA. From the 11 LGAs examined, nine experienced an outbreak in 2011/12 of which the models for these sites were a good fit. All 11 LGAs experienced an outbreak in 2016/17, however only six LGAs could predict the outbreak using the same model. We document similarities and differences in factors useful for forecasting RRV notifications across Victoria and demonstrate that readily available and inexpensive climate and environmental data can be used to predict epidemic periods in some areas. Furthermore, we highlight in certain regions the complexity of RRV transmission where additional epidemiological information is needed to accurately predict RRV activity. Our findings have been applied to produce a Ross River virus Outbreak Surveillance System (ROSS) to aid in public health decision making in Victoria.
Urban landscapes can change virus gene flow and evolution in a fragmentation‐sensitive carnivore
Publisher: Wiley
Date: 11-2017
DOI: 10.1111/MEC.14375
Abstract: Urban expansion has widespread impacts on wildlife species globally, including the transmission and emergence of infectious diseases. However, there is almost no information about how urban landscapes shape transmission dynamics in wildlife. Using an innovative phylodynamic approach combining host and pathogen molecular data with landscape characteristics and host traits, we untangle the complex factors that drive transmission networks of feline immunodeficiency virus (FIV) in bobcats (Lynx rufus). We found that the urban landscape played a significant role in shaping FIV transmission. Even though bobcats were often trapped within the urban matrix, FIV transmission events were more likely to occur in areas with more natural habitat elements. Urban fragmentation also resulted in lower rates of pathogen evolution, possibly owing to a narrower range of host genotypes in the fragmented area. Combined, our findings show that urban landscapes can have impacts on a pathogen and its evolution in a carnivore living in one of the most fragmented and urban systems in North America. The analytical approach used here can be broadly applied to other host-pathogen systems, including humans.
Patterns of SARS-CoV-2 exposure and mortality suggest endemic infections, in addition to space and population factors, shape dynamics across countries
Publisher: Cold Spring Harbor Laboratory
Date: 16-07-2021
DOI: 10.1101/2021.07.12.21260394
Abstract: Some countries have been crippled by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic while others have emerged with few infections and fatalities the factors underscoring this macro-epidemiological variation is one of the mysteries of this global catastrophe. Variation in immune responses influence SARS-CoV-2 transmission and mortality, and factors shaping this variation at the country level, in addition to other socio-ecological drivers, may be important. Here, we construct spatially explicit Bayesian models that combine data on prevalence of endemic diseases and other socio-ecological characteristics to quantify patterns of confirmed deaths and cases across the globe before mass vaccination. We find that the prevalence of parasitic worms, human immunodeficiency virus and malaria play a surprisingly important role in predicting country-level SARS-CoV-2 patterns. When combined with factors such as population density, our models predict 63% (56-67) and 76% (69-81) of confirmed cases and deaths among countries, respectively. While our findings at this macro-scale are necessarily associative, they highlight a need for studies to consider factors, such as infection by other pathogens, on global SARS-CoV-2 dynamics. These relationships are vital for developing countries that already have the highest burden of endemic disease and are becoming the most affected by the SARS-CoV-2 pandemic.
Abundance and population growth estimates for bare‐nosed wombats
Publisher: Wiley
Date: 09-2023
DOI: 10.1002/ECE3.10465
Relationships of the Ross River virus (Togoviridae: Alphavirus) vector, Aedes camptorhynchus (Thomson) (Diptera: Culicidae), to biotic and abiotic factors in saltmarshes of south-eastern Tasmania, Australia: A preliminary study
Publisher: Wiley
Date: 16-05-2011
Colonization of ephemeral water bodies in the wheatbelt of Western Australia by assemblages of mosquitoes (Diptera: Culicidae): Role of environmental factors, habitat, and disturbance
Publisher: Oxford University Press (OUP)
Date: 12-2009
DOI: 10.1603/022.038.0609
Abstract: Environmental disturbance may have direct and indirect impacts on organisms. We studied the colonization of ephemeral water bodies by mosquitoes (Diptera: Culicidae) in the Wheatbelt region of southwest Western Australia, an area substantially affected by an expanding anthropogenic salinization. Mosquitoes frequently colonized ephemeral water bodies, responded positively to rainfall, and populated smaller water bodies more densely than larger water bodies. We found that the habitat characteristics of ephemeral water bodies changed in association with salinity. Consequently relationships between salinity and abundance of colonizing mosquitoes were direct (salinity-mosquito) and indirect (salinity-water body characteristics-mosquito). Overall, the structure of mosquito assemblages changed with increasing salinity, favoring an increased regional distribution and abundance of Aedes c torhynchus Thomson (Diptera: Culicidae), a vector of Ross river virus (RRV Togoviridae: Alphavirus). We conclude secondary salinization in the Western Australia Wheatbelt results in enhanced vectorial potential for RRV transmission.
How to make more from exposure data? An integrated machine learning pipeline to predict pathogen exposure
Publisher: Wiley
Date: 19-08-2019
Abstract: Predicting infectious disease dynamics is a central challenge in disease ecology. Models that can assess which in iduals are most at risk of being exposed to a pathogen not only provide valuable insights into disease transmission and dynamics but can also guide management interventions. Constructing such models for wild animal populations, however, is particularly challenging often only serological data are available on a subset of in iduals and nonlinear relationships between variables are common. Here we provide a guide to the latest advances in statistical machine learning to construct pathogen-risk models that automatically incorporate complex nonlinear relationships with minimal statistical assumptions from ecological data with missing data. Our approach compares multiple machine learning algorithms in a unified environment to find the model with the best predictive performance and uses game theory to better interpret results. We apply this framework on two major pathogens that infect African lions: canine distemper virus (CDV) and feline parvovirus. Our modelling approach provided enhanced predictive performance compared to more traditional approaches, as well as new insights into disease risks in a wild population. We were able to efficiently capture and visualize strong nonlinear patterns, as well as model complex interactions between variables in shaping exposure risk from CDV and feline parvovirus. For ex le, we found that lions were more likely to be exposed to CDV at a young age but only in low rainfall years. When combined with our data calibration approach, our framework helped us to answer questions about risk of pathogen exposure that are difficult to address with previous methods. Our framework not only has the potential to aid in predicting disease risk in animal populations, but also can be used to build robust predictive models suitable for other ecological applications such as modelling species distribution or ersity patterns.
Towards an eco‐phylogenetic framework for infectious disease ecology
Publisher: Wiley
Date: 08-11-2017
DOI: 10.1111/BRV.12380
Abstract: Identifying patterns and drivers of infectious disease dynamics across multiple scales is a fundamental challenge for modern science. There is growing awareness that it is necessary to incorporate multi-host and/or multi-parasite interactions to understand and predict current and future disease threats better, and new tools are needed to help address this task. Eco-phylogenetics (phylogenetic community ecology) provides one avenue for exploring multi-host multi-parasite systems, yet the incorporation of eco-phylogenetic concepts and methods into studies of host pathogen dynamics has lagged behind. Eco-phylogenetics is a transformative approach that uses evolutionary history to infer present-day dynamics. Here, we present an eco-phylogenetic framework to reveal insights into parasite communities and infectious disease dynamics across spatial and temporal scales. We illustrate how eco-phylogenetic methods can help untangle the mechanisms of host-parasite dynamics from in idual (e.g. co-infection) to landscape scales (e.g. parasite/host community structure). An improved ecological understanding of multi-host and multi-pathogen dynamics across scales will increase our ability to predict disease threats.
Mosquito distribution in a saltmarsh: determinants of eggs in a variable environment
Publisher: Society for Vector Ecology
Date: 15-05-2017
DOI: 10.1111/JVEC.12251
Abstract: Two saltmarsh mosquitoes dominate the transmission of Ross River virus (RRV, Togoviridae: Alphavirus), one of Australia's most prominent mosquito-borne diseases. Ecologically, saltmarshes vary in their structure, including habitat types, hydrological regimes, and ersity of aquatic fauna, all of which drive mosquito oviposition behavior. Understanding the distribution of vector mosquitoes within saltmarshes can inform early warning systems, surveillance, and management of vector populations. The aim of this study was to identify the distribution of Ae. c torhynchus, a known vector for RRV, across a saltmarsh and investigate the influence that other invertebrate assemblage might have on Ae. c torhynchus egg dispersal. We demonstrate that vegetation is a strong indicator for Ae. c torhynchus egg distribution, and this was not correlated with elevation or other invertebrates located at this saltmarsh. Also, habitats within this marsh are less frequently inundated, resulting in dryer conditions. We conclude that this information can be applied in vector surveillance and monitoring of temperate saltmarsh environments and also provides a baseline for future investigations into understanding mosquito vector habitat requirements.
Another Emerging Mosquito-Borne Disease? Endemic Ross River Virus Transmission in the Absence of Marsupial Reservoirs
Publisher: Oxford University Press (OUP)
Date: 07-03-2018
Sarcoptes scabiei: The mange mite with mighty effects on the common wombat (Vombatus ursinus)
Publisher: Public Library of Science (PLoS)
Date: 04-03-2016
LABORATORY DETERMINATION OF EFFICACY OF A SANTALUM SPICATUM EXTRACT FOR MOSQUITO CONTROL
Publisher: The American Mosquito Control Association
Date: 09-2007
Intestines of non-uniform stiffness mold the corners of wombat feces
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D0SM01230K
Abstract: The bare-nosed wombat ( Vombatus ursinus ) is a fossorial, herbivorous, Australian marsupial, renowned for its cubic feces.
The treatment of sarcoptic mange in wildlife: a systematic review
Publisher: Springer Science and Business Media LLC
Date: 13-03-2019
A temporal dilution effect: hantavirus infection in deer mice and the intermittent presence of voles in Montana
Publisher: Springer Science and Business Media LLC
Date: 19-12-2010
Characterising the spatio-temporal threats, conservation hotspots, and conservation gaps for the most extinction-prone bird family (Aves: Rallidae).
Publisher: Cold Spring Harbor Laboratory
Date: 21-01-2021
DOI: 10.1101/2021.01.20.427508
Abstract: With thousands of vertebrate species now threatened with extinction, there is an urgent need to understand and mitigate the causes of wildlife collapse. As distinct evolutionary clades can follow different routes to endangerment, there is value in taxon-specific analyses when assessing species’ vulnerability to threats and identifying gaps in conservation actions. Rails (Aves: Rallidae), being the most extinction-prone bird Family globally, and with one third of extant rail species now threatened or near-threatened, are an emphatic case in point. Yet even for this well-studied group, there is uncertainty in our understanding of what factors might be causing this vulnerability, whether the current threats are consistent with those that led to recent extinctions, and ultimately, what conservation actions might be necessary to mitigate further losses. Here, we undertook a global synthesis of the temporal and spatial threat patterns for Rallidae and determined conservation priorities and gaps. We found two key pathways in the threat pattern for rails. One follows the same trajectory as extinct rails, where island endemic and flightless rails are most threatened, mainly due to invasive predators. The second, created by the recent ersification of anthropogenic activities, involves continental rails (generally in the Neotropics), threatened most commonly by agriculture, natural-system modifications and residential and commercial development. Conservation efforts around most-at-risk species should be adapted according to the most relevant geographic scale (bioregions or countries), and principal locality type of the population (continental or island endemic). Indonesia, the U.S.A., the United Kingdom, New Zealand, and Cuba were the priority countries identified by our classification system incorporating species’ unique evolutionary features and level of endangerment, but also among the countries that lack conservation actions the most. Future efforts should predominantly target improvements in ecosystem protection and management, as well as ongoing research and monitoring. Forecasting the impacts of climate change on island endemic rails and disentangling the specific roles of extrinsic and intrinsic traits (like flightlessness), will be particularly valuable avenues of research for improving our forecasts of rail vulnerability.
Prion-Seeding Activity in Cerebrospinal Fluid of Deer with Chronic Wasting Disease
Publisher: Public Library of Science (PLoS)
Date: 25-11-2013
Relationship of Human Behavior within Outbuildings to Potential Exposure to Sin Nombre Virus in Western Montana
Publisher: Springer Science and Business Media LLC
Date: 28-05-2010
DOI: 10.1007/S10393-010-0318-X
Abstract: Sin Nombre virus (SNV) causes hantavirus cardiopulmonary syndrome (HCPS) in humans. Transmission of SNV among the deer mouse (Peromyscus maniculatus) host predominates during spring and summer, and is greater in peridomestic than sylvan settings where, protected from UV light, SNV may survive longer. Incidence of HCPS reflects these times and settings and is associated with inhalation of mouse excreta. Little is known, however, about how human use of outbuildings contributes to potential exposure to SNV. Here, the frequency and seasonality of outbuilding use by humans was evaluated, via a survey of rural residents in western Montana, to quantify human behaviors and potential risk of exposure to SNV. Retrieving or return of tools and scooping feed/grain were the most frequently undertaken activities. Seasonal activities coinciding with seasons of highest HCPS incidence and times of potentially high viral shedding by deer mice, included retrieving or returning tools, calving or lambing, and, to a lesser extent, feeding livestock and sweeping or cleaning. Human behavior is a component of SNV transmission risk and this preliminary study provides a basis from which to further evaluate this route of exposure.
Transmission pathways and spillover of an erythrocytic bacterial pathogen from domestic cats to wild felids
Publisher: Wiley
Date: 11-09-2018
DOI: 10.1002/ECE3.4451
Molecular evidence of Chlamydia pecorum and arthropod-associated Chlamydiae in an expanded range of marsupials
Publisher: Springer Science and Business Media LLC
Date: 09-10-2017
DOI: 10.1038/S41598-017-13164-Y
Abstract: The order Chlamydiales are biphasic intracellular bacterial pathogens infecting humans and domesticated animals. Wildlife infections have also been reported, with the most studied ex le being Chlamydia pecorum infections in the koala, an iconic Australian marsupial. In koalas, molecular evidence suggests that spill-over from C. pecorum infected livestock imported into Australia may have had a historical or contemporary role. Despite preliminary evidence that other native Australian marsupials also carry C. pecorum , their potential as reservoirs of this pathogen and other Chlamydia -related bacteria (CRBs) has been understudied. Mucosal epithelial s les collected from over 200 native Australian marsupials of different species and geographic regions across Australia were PCR screened for Chlamydiales . Previously described and genetically distinct C. pecorum genotypes and a range of 16S rRNA genotypes sharing similarity to different CRBs in the broader Chlamydiales order were present. One 16S rRNA Chlamydiales genotype recently described in Australian ticks that parasitise native Australian marsupials was also identified. This study provides further evidence that chlamydial infections are widespread in native fauna and that detailed investigations are required to understand the influence these infections have on host species conservation, but also whether infection spill-over plays a role in their epidemiology.
Infectious disease and emergency conservation interventions
Publisher: Wiley
Date: 22-07-2020
DOI: 10.1111/COBI.13558
Human Exposure to Particulate Matter Potentially Contaminated with Sin Nombre Virus
Publisher: Springer Science and Business Media LLC
Date: 27-03-2013
Pathogens in space: Advancing understanding of pathogen dynamics and disease ecology through landscape genetics
Publisher: Wiley
Date: 28-07-2018
DOI: 10.1111/EVA.12678
Epidemic host community contribution to mosquito-borne disease transmission: Ross River virus
Publisher: Cambridge University Press (CUP)
Date: 28-11-2017
DOI: 10.1017/S0950268816002739
Abstract: Most vector-borne diseases infect multiple host species, but disentangling the relative importance of different host species to transmission can be complex. Here we study how host species’ abundance and competence (duration and titre of parasitaemia) influence host importance during epidemic scenarios. We evaluate this theory using Ross River virus (RRV, family Togaviridae, genus Alphavirus ), a multi-host mosquito-borne disease with significant human health impacts across Australia and Papua New Guinea. We used host contribution models to find the importance of key hosts (possums, wallabies, kangaroos, horses, humans) in typical mammal communities around five Australian epidemic centres. We found humans and possums contributed most to epidemic RRV transmission, owing to their high abundances, generally followed by macropods. This supports humans as spillover hosts, and that human–mosquito and possum–mosquito transmission is predominant during epidemics. Sensitivity analyses indicate these findings to be robust across epidemic centres. We emphasize the importance of considering abundance and competence in identifying key hosts (during epidemics in this case), and that competence alone is inadequate. Knowledge of host importance in disease transmission may help to equip health agencies to bring about greater effectiveness of disease mitigation strategies.
Behavioural syndromes and structural and temporal consistency of behavioural traits in a social lizard
Publisher: Wiley
Date: 29-01-2015
DOI: 10.1111/JZO.12217
Navigating to the most promising directions amid complex fields of vaccine development: a chlamydial case study
Publisher: Informa UK Limited
Date: 02-12-2019
Maternal protectiveness in feral horses: responses to intraspecific and interspecific sources of risk
Publisher: Elsevier BV
Date: 2020
Hunting alters viral transmission and evolution
Publisher: Research Square Platform LLC
Date: 12-06-2021
DOI: 10.21203/RS.3.RS-590207/V1
Abstract: Hunting can fundamentally alter wildlife population dynamics, but the consequences of hunting on pathogen transmission and evolution remain poorly understood. Here we present a study that leverages a unique landscape-scale experiment coupled with pathogen transmission tracing, network simulation and phylodynamics to provide insights into how hunting shapes viral dynamics in puma ( Puma concolor ). We show that removing hunting pressure enhances the role of males in transmission, increases the viral population growth rate and the role of evolutionary forces on the pathogen compared to when hunting was reinstated. Changes in transmission could be linked to short term social changes while the male population increased. These findings are supported through comparison with a region with stable hunting management over the same time period. This study shows that routine wildlife management can have impacts on pathogen transmission and evolution not previously considered.
Inferring the Ecological Niche of Toxoplasma gondii and Bartonella spp. in Wild Felids
Publisher: Frontiers Media SA
Date: 17-10-2017
The significance of topographic complexity in habitat selection and persistence of a declining marsupial in the Kimberley region of Western Australia
Publisher: CSIRO Publishing
Date: 2016
DOI: 10.1071/ZO16015
Abstract: Mammalian species in northern Australia are declining. The resources that many species from this region require to persist in the landscape remain poorly understood. We examined habitat selection and diet of the scaly-tailed possum (Wyulda squamicaudata, hereafter called Wyulda) in the north-west Kimberley, Western Australia, in relation to variation in complexity of rocky habitat, habitat heterogeneity, and recent fire history. We fitted GPS tags to 23 Wyulda between January 2013 and February 2014 and analysed step selection between GPS fixes to describe habitat choice. We assessed diet by microscopic analysis of plant fragments from 47 faecal s les. In idual Wyulda preferentially foraged in locations with high rock complexity and high habitat heterogeneity in a wide variety of habitats, but denned exclusively in complex rock piles. They used savannas of a range of post-fire ages, including recently burnt (1–2 months after fire) and long unburnt ( months after fire). They were highly frugivorous with, on average, 77% of plant fragments per scat s le identified as fruit epidermal layers. Overall, rock complexity appears to be an important landscape attribute for Wyulda, as it may provide den sites and protect fire-sensitive landscape features such as fruiting trees and habitat heterogeneity.
Effects of salinity and flow interactions on macroinvertebrate traits in temporary streams
Publisher: Elsevier BV
Date: 06-2018
A model for the treatment of environmentally transmitted sarcoptic mange in bare-nosed wombats (Vombatus ursinus)
Publisher: Elsevier BV
Date: 02-2019
DOI: 10.1016/J.JTBI.2018.11.033
Abstract: Some of the most important wildlife diseases involve environmental transmission, with disease control attempted via treatments that induce temporary pathogen resistance among hosts. However, theoretical explanations of such circumstances remain few. A mathematical model is proposed and investigated to analyse the dynamics and treatment of environmentally transmitted sarcoptic mange in a population of bare-nosed wombats. The wombat population is structured into four classes representing stages of infection, in a model that consists of five non-linear differential equations including the unattached mite population. It is shown that four different epidemiological outcomes are possible. These are: (1) extinction of wombats (and mites) (2) mite-free wombat populations (3) endemic wombats and mites coexisting, with the wombats' population reduced below the environmental carrying capacity and (4) a stable limit cycle (sustained oscillating populations) with wombat population far below carrying capacity. Empirical evidence exists for the first two of these outcomes, with the third highly likely to occur in nature, and the fourth plausible at least until wombat populations succumb to Allee effects. These potential outcomes are examined to inform treatment programs for wombat populations. Through this theoretical exploration of a relatively well understood empirical system, this study supports general learning across environmentally transmitted wildlife pathogens, increasing understanding of how pathogen dynamics may cause crashes in some populations and not others.
Biological and cultural coevolution and emerging infectious disease: Ross River virus in Australia
Publisher: Elsevier BV
Date: 06-2011
DOI: 10.1016/J.MEHY.2011.03.001
Abstract: Enhanced virulence of pathogens infecting host populations, with no previous exposure thereto, is characteristic of many diseases labelled "emerging" or "resurging". One cause of emergence characteristics can be interpreted as absence of co-evolutionary optimization of interactions between hosts and pathogens. We explore the historical and evolutionary development between Ross River virus (RRV) and its human host in Australia a mosquito vectored pathogen causing polyarthritic symptoms. Epidemics of RRV have increased in frequency, size and range throughout European settlement. We hypothesise that human cultural evolution contributed to the emergence of RRV in humans, and argue that epidemics of RRV were unlikely to occur in Aboriginal hunter-gatherer societies in Australia's early human history, but only occur in more recent agrarian and industrial societies. A perspective of cultural evolution, in addition to biological evolution, may help with understanding the determinants of disease emergence and resurgence, and inform ongoing development of effective public health interventions.
Density independent decline from an environmentally transmitted parasite
Publisher: The Royal Society
Date: 08-2023
Abstract: Invasive environmentally transmitted parasites have the potential to cause declines in host populations independent of host density, but this is rarely characterized in naturally occurring populations. We investigated (1) epidemiological features of a declining bare-nosed wombat ( Vombatus ursinus ) population in central Tasmania owing to a sarcoptic mange (agent Sarcoptes scabiei ) outbreak, and (2) reviewed all longitudinal wombat–mange studies to improve our understanding of when host population declines may occur. Over a 7-year period, the wombat population declined 80% (95% CI 77–86%) and experienced a 55% range contraction. The average apparent prevalence of mange was high 27% (95% CI 21–34), increased slightly over our study period, and the population decline continued unabated, independent of declining host abundance. Combined with other longitudinal studies, our research indicated wombat populations may be at risk of decline when apparent prevalence exceeds 25%. This empirical study supports the capacity of environmentally transmitted parasites to cause density independent host population declines and suggests prevalence limits may be an indicator of impending decline-causing epizootics in bare-nosed wombats. This research is the first to test effects of density in mange epizootics where transmission is environmental and may provide a guide for when apparent prevalence indicates a local conservation threat.
The limitations of commercial serological assays for detection of chlamydial infections in Australian livestock
Publisher: Microbiology Society
Date: 04-2019
DOI: 10.1099/JMM.0.000951
Abstract: Chlamydia pecorum and Chlamydia abortus are related ruminant pathogens endemic to different global regions. Potential co-infections combined with the lack of species-specific serological assays challenge accurate diagnosis. Serological screening revealed low C. abortus seropositivity with the peptide-based ELISA (1/84 1.2%) in Australian sheep yet moderate seropositivity in a Swiss flock with history of C. abortus-associated abortions (17/63 26.9%). By whole cell antigen complement fixation tests (CFT) and ELISA, chlamydial seropositivity was significantly higher in all groups, suggesting cross-reactivity between these two chlamydial species and non-specificity of the tests. However, only C. pecorum DNA could be detected by qPCR in Chlamydia seropositive Australian animals screened, suggesting chlamydial seropositivity was due to cross-reactivity with endemic C. pecorum infections. These results suggest ascribing Chlamydia seropositivity to chlamydial species in livestock using whole-cell antigen CFT or ELISA should be treated with caution and that peptide-based ELISA and qPCR provide greater chlamydial species-specificity.
Optimising predictive modelling of Ross River virus using meteorological variables
Publisher: Public Library of Science (PLoS)
Date: 09-03-2021
DOI: 10.1371/JOURNAL.PNTD.0009252
Abstract: Statistical models are regularly used in the forecasting and surveillance of infectious diseases to guide public health. Variable selection assists in determining factors associated with disease transmission, however, often overlooked in this process is the evaluation and suitability of the statistical model used in forecasting disease transmission and outbreaks. Here we aim to evaluate several modelling methods to optimise predictive modelling of Ross River virus (RRV) disease notifications and outbreaks in epidemiological important regions of Victoria and Western Australia. We developed several statistical methods using meteorological and RRV surveillance data from July 2000 until June 2018 in Victoria and from July 1991 until June 2018 in Western Australia. Models were developed for 11 Local Government Areas (LGAs) in Victoria and seven LGAs in Western Australia. We found generalised additive models and generalised boosted regression models, and generalised additive models and negative binomial models to be the best fit models when predicting RRV outbreaks and notifications, respectively. No association was found with a model’s ability to predict RRV notifications in LGAs with greater RRV activity, or for outbreak predictions to have a higher accuracy in LGAs with greater RRV notifications. Moreover, we assessed the use of factor analysis to generate independent variables used in predictive modelling. In the majority of LGAs, this method did not result in better model predictive performance. We demonstrate that models which are developed and used for predicting disease notifications may not be suitable for predicting disease outbreaks, or vice versa . Furthermore, poor predictive performance in modelling disease transmissions may be the result of inappropriate model selection methods. Our findings provide approaches and methods to facilitate the selection of the best fit statistical model for predicting mosquito-borne disease notifications and outbreaks used for disease surveillance.
Invasive pathogen drives host population collapse: Effects of a travelling wave of sarcoptic mange on bare-nosed wombats
Publisher: Wiley
Date: 23-08-2017
Transmission of one predicts another: Apathogenic proxies for transmission dynamics of a fatal virus
Publisher: Cold Spring Harbor Laboratory
Date: 09-01-2021
DOI: 10.1101/2021.01.09.426055
Abstract: Identifying drivers of transmission prior to an epidemic—especially of an emerging pathogen—is a formidable challenge for proactive disease management efforts. We tested a novel approach in the Florida panther, hypothesizing that apathogenic feline immunodeficiency virus (FIV) transmission could predict transmission dynamics for pathogenic feline leukemia virus (FeLV). We derived a transmission network using FIV whole genome sequences, and used exponential random graph models to determine drivers structuring this network. We used these drivers to predict FeLV transmission pathways among panthers and compared predicted outbreak dynamics against empirical FeLV outbreak data. FIV transmission was primarily driven by panther age class and distances between panther home range centroids. Prospective FIV-based modeling predicted FeLV dynamics at least as well as simpler, often retrospective approaches, with evidence that FIV-based predictions captured the spatial structuring of the observed FeLV outbreak. Our finding that an apathogenic agent can predict transmission of an analogously transmitted pathogen is an innovative approach that warrants testing in other host-pathogen systems to determine generalizability. Use of such apathogenic agents holds promise for improving predictions of pathogen transmission in novel host populations, and could thereby provide new strategies for proactive pathogen management in human and animal systems.
Detection of Chronic Wasting Disease in the Lymph Nodes of Free-Ranging Cervids by Real-Time Quaking-Induced Conversion
Publisher: American Society for Microbiology
Date: 09-2014
DOI: 10.1128/JCM.01258-14
Abstract: Chronic wasting disease (CWD), a transmissible spongiform encephalopathy of deer, elk, and moose, is the only prion disease affecting free-ranging animals. Since the disease was first identified in northern Colorado and southern Wyoming in 1967, new epidemic foci of the disease have been identified in 20 additional states, as well as two Canadian provinces and the Republic of South Korea. Identification of CWD-affected animals currently requires postmortem analysis of brain or lymphoid tissues using immunohistochemistry (IHC) or an enzyme-linked immunosorbent assay (ELISA), with no practical way to evaluate potential strain types or to investigate the epidemiology of existing or novel foci of disease. Using a standardized real-time (RT)-quaking-induced conversion (QuIC) assay, a seeded lification assay employing recombinant prion protein as a conversion substrate and thioflavin T (ThT) as an amyloid-binding fluorophore, we analyzed, in a blinded manner, 1,243 retropharyngeal lymph node s les from white-tailed deer, mule deer, and moose, collected in the field from areas with current or historic CWD endemicity. RT-QuIC results were then compared with those obtained by conventional IHC and ELISA, and lification metrics using ThT and thioflavin S were examined in relation to the clinical history of the s led deer. The results indicate that RT-QuIC is useful for both identifying CWD-infected animals and facilitating epidemiological studies in areas in which CWD is endemic or not endemic.
How do local differences in saltmarsh ecology influence disease vector mosquito populations?
Publisher: Wiley
Date: 20-02-2020
DOI: 10.1111/MVE.12433
Abstract: Saltmarsh breeding mosquitoes are an important source of vectors for arboviral transmission. In southern Australia, the most prominent vector borne disease, Ross River virus (Togaviridae: Alphavirus ) (RRV), is transmitted by the saltmarsh mosquito (Diptera: Culicidae) Aedes c torhynchus (Thomson). However, the factors driving the abundance of this mosquito within and among saltmarshes are poorly understood. To predict the abundance of this mosquito within saltmarshes, the environmental conditions and aquatic invertebrate ecology of three temperate saltmarshes habitats were monitored over two seasons. Up to 44% of first‐instar mosquito numbers and 21% of pupal numbers were accounted for by environmental variables. S hire vegetation cover was a common predictor of first‐instar numbers across sites although, between saltmarshes, aquatic factors such as high salinity, temperatures less than 22 °C and water body volume were important predictors. The identified predictors of pupal numbers were more variable and included high tides, waterbody volume and alkalinity. The composition of invertebrate functional feeding groups differed between saltmarshes and showed that an increased ersity led to fewer mosquitoes. It was evident that apparently similar saltmarshes can vary markedly in invertebrate assemblages, water availability and conditions through tidal inundations, rainfall or waterbody permanency. The present study advances insight into predictors of vector mosquito numbers that drive the risk of RRV outbreaks.
Sex bias in ability to cope with cancer: Tasmanian devils and facial tumour disease
Publisher: The Royal Society
Date: 21-11-2018
Abstract: Knowledge of the ecological dynamics between hosts and pathogens during the initial stages of disease emergence is crucial to understanding the potential for evolution of new interspecific interactions. Tasmanian devil ( Sarcophilus harrisii ) populations have declined precipitously owing to infection by a transmissible cancer (devil facial tumour disease, DFTD) that emerged approximately 20 years ago. Since the emergence of DFTD, and as the disease spreads across Tasmania, the number of devils has dropped up to 90% across 80% of the species's distributional range. As a result, the disease is expected to act as a strong selective force on hosts to develop mechanisms of tolerance and/or resistance to the infection. We assessed the ability of infected devils to cope with infection, which translates into host tolerance to the cancer, by using the reaction norm of the in idual body condition by tumour burden. We found that body condition of infected hosts is negatively affected by cancer progression. Males and females presented significant differences in their tolerance levels to infection, with males suffering declines of up to 25% of their body condition, in contrast to less than 5% in females. Sex-related differences in tolerance to cancer progression may select for changes in life-history strategies of the host and could also alter the selective environment for the tumours.
Meta-transcriptomic identification of Trypanosoma spp. in native wildlife species from Australia.
Publisher: Springer Science and Business Media LLC
Date: 05-09-2020
DOI: 10.1186/S13071-020-04325-6
Abstract: Wildlife species carry a remarkable ersity of trypanosomes. The detection of trypanosome infection in native Australian fauna is central to understanding their ersity and host-parasite associations. The implementation of total RNA sequencing (meta-transcriptomics) in trypanosome surveillance and diagnosis provides a powerful methodological approach to better understand the host species distribution of this important group of parasites. We implemented a meta-transcriptomic approach to detect trypanosomes in a variety of tissues (brain, liver, lung, skin, gonads) s led from native Australian wildlife, comprising four marsupials (koala, Phascolarctos cinereus southern brown bandicoot, Isoodon obesulus sw wallaby, Wallabia bicolor bare-nosed wombat, Vombatus ursinus ), one bird (regent honeyeater, Anthochaera phrygia ) and one hibian (eastern dwarf tree frog, Litoria fallax ). S les corresponded to both clinically healthy and diseased in iduals. Sequencing reads were de novo assembled into contigs and annotated. The evolutionary relationships among the trypanosomatid sequences identified were determined through phylogenetic analysis of 18S rRNA sequences. We detected trypanosome sequences in all six species of vertebrates s led, with positive s les in multiple organs and tissues confirmed by PCR. Phylogenetic analysis indicated that the trypanosomes infecting marsupials were related to those previously detected in placental and marsupial mammals, while the trypanosome in the regent honeyeater grouped with avian trypanosomes. In contrast, we provide the first evidence for a trypanosome in the eastern dwarf tree frog that was phylogenetically distinct from those described in other hibians. To our knowledge, this is the first meta-transcriptomic analysis of trypanosomes in native Australian wildlife, expanding the known genetic ersity of these important parasites. We demonstrated that RNA sequencing is sufficiently sensitive to detect low numbers of Trypanosoma transcripts and from erse hosts and tissues types, thereby representing an effective means to detect trypanosomes that are ergent in genome sequence.
Salinity as a driver of aquatic invertebrate colonisation behaviour and distribution in the wheatbelt of Western Australia
Publisher: Springer Science and Business Media LLC
Date: 08-2009
Prior Puma lentivirus infection modifies early immune responses and attenuates feline immunodeficiency virus infection in cats
Publisher: MDPI AG
Date: 20-04-2018
DOI: 10.3390/V10040210
Urbanization reduces genetic connectivity in bobcats (Lynx rufus) at both intra– and interpopulation spatial scales
Publisher: Wiley
Date: 12-11-2019
DOI: 10.1111/MEC.15274
Abstract: Urbanization is a major factor driving habitat fragmentation and connectivity loss in wildlife. However, the impacts of urbanization on connectivity can vary among species and even populations due to differences in local landscape characteristics, and our ability to detect these relationships may depend on the spatial scale at which they are measured. Bobcats (Lynx rufus) are relatively sensitive to urbanization and the status of bobcat populations is an important indicator of connectivity in urban coastal southern California. We genotyped 271 bobcats at 13,520 SNP loci to conduct a replicated landscape resistance analysis in five genetically distinct populations. We tested urban and natural factors potentially influencing in idual connectivity in each population separately, as well as study-wide. Overall, landscape genomic effects were most frequently detected at the study-wide spatial scale, with urban land cover (measured as impervious surface) having negative effects and topographic roughness having positive effects on gene flow. The negative effect of urban land cover on connectivity was also evident when populations were analyzed separately despite varying substantially in spatial area and the proportion of urban development, confirming a pervasive impact of urbanization largely independent of spatial scale. The effect of urban development was strongest in one population where stream habitat had been lost to development, suggesting that riparian corridors may help mitigate reduced connectivity in urbanizing areas. Our results demonstrate the importance of replicating landscape genetic analyses across populations and considering how landscape genetic effects may vary with spatial scale and local landscape structure.
Influence of Hosts on the Ecology of Arboviral Transmission: Potential Mechanisms Influencing Dengue, Murray Valley Encephalitis, and Ross River Virus in Australia
Publisher: Mary Ann Liebert Inc
Date: 02-2009
Abstract: Ecological interactions are fundamental to the transmission of infectious disease. Arboviruses are particularly elegant ex les, where rich arrays of mechanisms influence transmission between vectors and hosts. Research on host contributions to the ecology of arboviral diseases has been undertaken within multiple subdisciplines, but significant gaps in knowledge remain and multidisciplinary approaches are needed. Through our multidisciplinary review of the literature we have identified five broad areas where hosts may influence the ecology of arboviral transmission: host immunity cross-protective immunity and antibody-dependent enhancement host abundance host ersity and pathogen spillover and dispersal. Herein we discuss the known and theoretical roles of hosts within these topics and then apply this knowledge to three epidemiologically important mosquito-borne arboviruses that occur in Australia: dengue virus (DENV), Murray Valley encephalitis virus (MVEV), and Ross River virus (RRV). We argue that the underlying mechanisms by which hosts influence arboviral activity are numerous and attempts to delineate these mechanisms further are needed. Investigations that focus on hosts of vector-borne diseases are likely to be rewarding, particularly where the ecology of vectors is relatively well understood. From an applied perspective, enhanced knowledge of host influences upon vector-borne disease transmission is likely to enable better management of disease burden. Finally, we suggest a framework that may be useful to identify and determine host contributions to the ecology of arboviruses.
Host, environment, and anthropogenic factors drive landscape dynamics of an environmentally transmitted pathogen: Sarcoptic mange in the bare‐nosed wombat
Publisher: Wiley
Date: 23-05-2023
Abstract: Understanding the spatial dynamics and drivers of wildlife pathogens is constrained by s ling logistics, with implications for advancing the field of landscape epidemiology and targeted allocation of management resources. However, visually apparent wildlife diseases, when combined with remote‐surveillance and distribution modelling technologies, present an opportunity to overcome this landscape‐scale problem. Here, we investigated dynamics and drivers of landscape‐scale wildlife disease, using clinical signs of sarcoptic mange (caused by Sarcoptes scabiei ) in its bare‐nosed wombat (BNW Vombatus ursinus ) host. We used 53,089 camera‐trap observations from over 3261 locations across the 68,401 km 2 area of Tasmania, Australia, combined with landscape data and ensemble species distribution modelling (SDM). We investigated: (1) landscape variables predicted to drive habitat suitability of the host (2) host and landscape variables associated with clinical signs of disease in the host and (3) predicted locations and environmental conditions at greatest risk of disease occurrence, including some Bass Strait islands where BNW translocations are proposed. We showed that the Tasmanian landscape, and ecosystems therein, are nearly ubiquitously suited to BNWs. Only high mean annual precipitation reduced habitat suitability for the host. In contrast, clinical signs of sarcoptic mange disease in BNWs were widespread, but heterogeneously distributed across the landscape. Mange (which is environmentally transmitted in BNWs) was most likely to be observed in areas of increased host habitat suitability, lower annual precipitation, near sources of freshwater and where topographic roughness was minimal (e.g. human modified landscapes, such as farmland and intensive land‐use areas, shrub and grass lands). Thus, a confluence of host, environmental and anthropogenic variables appear to influence the risk of environmental transmission of S. scabiei . We identified that the Bass Strait Islands are highly suitable for BNWs and predicted a mix of high and low suitability for the pathogen. This study is the largest spatial assessment of sarcoptic mange in any host species, and advances understanding of the landscape epidemiology of environmentally transmitted S. scabiei . This research illustrates how host‐pathogen co‐suitability can be useful for allocating management resources in the landscape.
Environmental suitability of bare-nosed wombat burrows for Sarcoptes scabiei
Publisher: Elsevier BV
Date: 12-2021
Isolation, marine transgression and translocation of the bare‐nosed wombat ( Vombatus ursinus )
Publisher: Wiley
Date: 21-03-2019
DOI: 10.1111/EVA.12785
Expanded Molecular Typing of Sarcoptes scabiei Provides Further Evidence of Disease Spillover Events in the Epidemiology of Sarcoptic Mange in Australian Marsupials
Publisher: Wildlife Disease Association
Date: 2019
DOI: 10.7589/2018-04-101
Abstract: The invasive ectoparasite Sarcoptes scabiei affects the welfare and conservation of Australian marsupials. Molecular data suggest that spillover from other hosts may be responsible for the emergence of this infectious disease, but the scale of such studies is limited. We performed expanded molecular typing of the S. scabiei mitochondrial cox1 gene from 81 skin scrapings from infested wombats ( Vombatus ursinus), koalas ( Phascolarctos cinereus), red foxes ( Vulpes vulpes), and dogs ( Canis lupus familiaris) across Australia. Combined with existing S. scabiei sequences, our analysis revealed 16 haplotypes among Australian animals, sharing between 93.3% and 99.7% sequence similarity. While some sequences were unique to specific hosts or to Australia, key haplotypes could be detected across several marsupial hosts as well as to wild or domestic canids in Australia. We identified 43 cox1 haplotypes with many Australian haplotypes identical to S. scabiei mites from inside and outside Europe. We concluded that multiple introduction events were plausible explanations to the origin and emergence of this parasite into Australian marsupials and that disease spillover from canids was likely. Together, our greatly expanded S. scabiei sequence dataset provided a more nuanced picture of both spillover and sustained intraspecific transmission for this important parasite.
Urbanization and anticoagulant poisons promote immune dysfunction in bobcats
Publisher: The Royal Society
Date: 17-01-2018
Abstract: Understanding how human activities influence immune response to environmental stressors can support bio ersity conservation across increasingly urbanizing landscapes. We studied a bobcat ( Lynx rufus ) population in urban southern California that experienced a rapid population decline from 2002–2005 due to notoedric mange. Because anticoagulant rodenticide (AR) exposure was an underlying complication in mange deaths, we aimed to understand sublethal contributions of urbanization and ARs on 65 biochemical markers of immune and organ function. Variance in immunological variables was primarily associated with AR exposure and secondarily with urbanization. Use of urban habitat and AR exposure has pervasive, complex and predictable effects on biochemical markers of immune and organ function in free-ranging bobcats that include impacts on neutrophil, lymphocyte and cytokine populations, total bilirubin and phosphorus. We find evidence of both inflammatory response and immune suppression associated with urban land use and rat poison exposure that could influence susceptibility to opportunistic infections. Consequently, AR exposure may influence mortality and has population-level effects, as previous work in the focal population has revealed substantial mortality caused by mange infection. The secondary effects of anticoagulant exposure may be a worldwide, largely unrecognized problem affecting a variety of vertebrate species in human-dominated environments.
Zoonotic Parasites of Bobcats around Human Landscapes
Publisher: American Society for Microbiology
Date: 09-2012
DOI: 10.1128/JCM.01558-12
Abstract: We analyzed Lynx rufus fecal parasites from California and Colorado, hypothesizing that bobcats shed zoonotic parasites around human landscapes. Giardia duodenalis , Cryptosporidium , Ancylostoma , Uncinaria , and Toxocara cati were shed. Toxoplasma gondii serology demonstrated exposure. Giardia and Cryptosporidium shedding increased near large human populations. Genotyped Giardia may indicate indirect transmission with humans.
Under‐representation of avian studies in landscape genetics
Publisher: Wiley
Date: 20-09-2017
DOI: 10.1111/IBI.12532
Urbanization impacts apex predator gene flow but not genetic diversity across an urban‐rural divide
Publisher: Wiley
Date: 11-2019
DOI: 10.1111/MEC.15261
Abstract: Apex predators are important indicators of intact natural ecosystems. They are also sensitive to urbanization because they require broad home ranges and extensive contiguous habitat to support their prey base. Pumas (Puma concolor) can persist near human developed areas, but urbanization may be detrimental to their movement ecology, population structure, and genetic ersity. To investigate potential effects of urbanization in population connectivity of pumas, we performed a landscape genomics study of 130 pumas on the rural Western Slope and more urbanized Front Range of Colorado, USA. Over 12,000 single nucleotide polymorphisms (SNPs) were genotyped using double-digest, restriction site-associated DNA sequencing (ddRADseq). We investigated patterns of gene flow and genetic ersity, and tested for correlations between key landscape variables and genetic distance to assess the effects of urbanization and other landscape factors on gene flow. Levels of genetic ersity were similar for the Western Slope and Front Range, but effective population sizes were smaller, genetic distances were higher, and there was more admixture in the more urbanized Front Range. Forest cover was strongly positively associated with puma gene flow on the Western Slope, while impervious surfaces restricted gene flow and more open, natural habitats enhanced gene flow on the Front Range. Landscape genomic analyses revealed differences in puma movement and gene flow patterns in rural versus urban settings. Our results highlight the utility of dense, genome-scale markers to document subtle impacts of urbanization on a wide-ranging carnivore living near a large urban center.
Prior Virus Exposure Alters the Long-Term Landscape of Viral Replication during Feline Lentiviral Infection
Publisher: MDPI AG
Date: 13-10-2011
DOI: 10.3390/V3101891
The recent decline of a New Zealand endemic: How and why did populations of Archey's frog Leiopelma archeyi crash over 1996-2001?
Publisher: Elsevier BV
Date: 11-2004
Is pathogen exposure spatially autocorrelated? Patterns of pathogens in puma (Puma concolor) and bobcat (Lynx rufus)
Publisher: Wiley
Date: 11-2016
DOI: 10.1002/ECS2.1558
Sarcoptic mange: An emerging panzootic in wildlife
Publisher: Hindawi Limited
Date: 02-05-2021
DOI: 10.1111/TBED.14082
Sensitivity of protein misfolding cyclic amplification versus immunohistochemistry in ante-mortem detection of chronic wasting disease
Publisher: Microbiology Society
Date: 05-2012
Abstract: As the only prion disease affecting free-ranging animals, ante-mortem identification of affected cervids has become paramount in understanding chronic wasting disease (CWD) pathogenesis, prevalence and control of horizontal or vertical transmission. To seek maximal sensitivity in ante-mortem detection of CWD infection, this study used paired tonsil biopsy s les collected at various time points from 48 CWD-exposed cervids to compare blinded serial protein misfolding cyclic lification (sPMCA) with the assay long considered the ‘gold standard’ for CWD detection, immunohistochemistry (IHC). sPMCA-negative controls (34 % of the s les evaluated) included tissues from mock-inoculated animals and unspiked negative controls, all of which tested negative throughout the course of the study. It was found that sPMCA on tonsil biopsies detected CWD infection significantly earlier (2.78 months, 95 % confidence interval 2.40–3.15) than conventional IHC. Interestingly, a correlation was observed between early detection by sPMCA and host PRNP genotype. These findings demonstrate that in vitro - lification assays provide enhanced sensitivity and advanced detection of CWD infection in the peripheral tissues of cervids, with a potential role for spike or substrate genotype in sPMCA lification efficiency.
MrIML: Multi‐response interpretable machine learning to model genomic landscapes
Publisher: Wiley
Date: 06-09-2021
Abstract: We introduce a new R package “MrIML” (“Mister iml” Multi‐response Interpretable Machine Learning). MrIML provides a powerful and interpretable framework that enables users to harness recent advances in machine learning to quantify multilocus genomic relationships, to identify loci of interest for future landscape genetics studies, and to gain new insights into adaptation across environmental gradients. Relationships between genetic variation and environment are often nonlinear and interactive these characteristics have been challenging to address using traditional landscape genetic approaches. Our package helps capture this complexity and offers functions that fit and interpret a wide range of highly flexible models that are routinely used for single‐locus landscape genetics studies but are rarely extended to estimate response functions for multiple loci. To demonstrate the package's broad functionality, we test its ability to recover landscape relationships from simulated genomic data. We also apply the package to two empirical case studies. In the first, we model genetic variation of North American balsam poplar ( Populus balsamifera , Salicaceae) populations across environmental gradients. In the second case study, we recover the landscape and host drivers of feline immunodeficiency virus genetic variation in bobcats ( Lynx rufus ). The ability to model thousands of loci collectively and compare models from linear regression to extreme gradient boosting, within the same analytical framework, has the potential to be transformative. The MrIML framework is also extendable and not limited to modelling genetic variation for ex le, it can quantify the environmental drivers of microbiomes and coinfection dynamics.
Health outcomes of beekeeping: a systematic review,Consecuencias sanitarias de la apicultura: una revisión sistemática
Publisher: Informa UK Limited
Date: 15-03-2017
The risky business of being an entomologist: A systematic review
Publisher: Elsevier BV
Date: 07-2015
DOI: 10.1016/J.ENVRES.2015.05.025
Abstract: Adverse work-related health outcomes are a significant problem worldwide. Entomologists, including arthropod breeders, are a unique occupational group exposed to potentially harmful arthropods, pesticides, and other more generic hazards. These exposures may place them at risk of a range of adverse work-related health outcomes. To determine what adverse work-related health outcomes entomologists have experienced, the incidence revalence of these outcomes, and what occupational management strategies have been employed by entomologists, and their effectiveness. A systematic search of eight databases was undertaken to identify studies informing the review objectives. Data pertaining to country, year, design, work-exposure, adverse work-related health outcomes, incidence revalence of these outcomes, and occupational management strategies were extracted, and reported descriptively. Results showed entomologists experienced work-related allergies, venom reactions, infections, infestations and delusional parasitosis. These related to exposure to insects, arachnids, chilopods and entognathans, and non-arthropod exposures, e.g. arthropod feed. Few studies reported the incidence revalence of such conditions, or work-related management strategies utilised by entomologists. There were no studies that specifically investigated the effectiveness of potential management strategies for entomologists as a population. Indeed, critical appraisal analysis indicated poor research quality in this area, which is a significant research gap. Entomologists are a erse, unique occupational group, at risk of a range of adverse work-related health outcomes. This study represents the first systematic review of their work-related health risks. Future studies investigating the prevalence of adverse work-related health outcomes for entomologists, and the effectiveness of management strategies are warranted to decrease the disease burden of this otherwise understudied group.
Resource limitation, controphic ostracod density and larval mosquito development
Publisher: Public Library of Science (PLoS)
Date: 11-11-2015
Characterization of Regionally Associated Feline Immunodeficiency Virus (FIV) in Bobcats (Lynx rufus)
Publisher: Wildlife Disease Association
Date: 07-2013
DOI: 10.7589/2012-10-243
Abstract: Feline immunodeficiency virus (FIV) classically infects felid species with highly ergent species-specific FIVs. However, recent studies have detected an FIV strain infecting both bobcats (Lynx rufus) and pumas (Puma concolor) in California and Florida. To further investigate this observation, we evaluated FIV from bobcats in Florida (n=25) and Colorado (n=80) between 2008 and 2011. Partial viral sequences from five Florida bobcats cluster with previously published sequences from Florida panthers. We did not detect FIV in Colorado bobcats.
Long‐Term Spatiotemporal Dynamics and Factors Associated with Trends in Bare‐Nosed Wombats
Publisher: Wiley
Date: 12-02-2021
DOI: 10.1002/JWMG.22014
Model Integrated Disease Management to facilitate effective translatable solutions for wildlife disease issues
Publisher: Wiley
Date: 30-09-2022
Abstract: There are multiple demands for the development of effective and sustainable disease management practices in wildlife, but solutions are widely lacking. In this perspective, we focus on the need to structure research to support advancement toward enhanced wildlife disease control solutions. We concentrate on the need for improved integration between wildlife disease management undertaken in situ with modelling to guide and assess disease management actions. We recognise that many disease management attempts in wildlife are made in isolation, are not supported by modelling and are not used as a stepping stone to advancement. However, we emphasise that the development of disease control practices in wildlife is greater than any one management attempt, and should be seen and undertaken as a set of systematic steps towards well‐articulated management goals. We describe modelling of disease management and in situ disease management as two complementary phases of investigation, viewed as a feedback loop to support advancements, and highlight established and less established pathways in this loop. We describe how stakeholders engaged in practical management actions can better engage with modellers, and also the need for more fit‐for‐purpose modelling that captures the on‐ground realities of in situ practice to support advancements. The concepts and approaches described in this perspective are captured within a Model Integrated Disease Management for wildlife framework. We illustrate the framework, concepts and challenges proposed in this perspective using a case study for which we have experience: sarcoptic mange (etiologic agent Sarcoptes scabiei ) in bare‐nosed wombats ( Vombatus ursinus ). Synthesis and applications : Effective and sustainable solutions to critical wildlife diseases are needed. Progress can be improved when disease management is guided through iterative and fit‐for‐purpose integration between modelling and in situ practice. We describe and illustrate a Model Integrated Disease Management for wildlife framework. Moving beyond isolated disease management attempts into a structured process of advancement can help overcome barriers to tackling pathogens threatening wildlife.
Closing the gap on causal processes of infection risk from cross-sectional data: structural equation models to understand infection and co-infection.
Publisher: Springer Science and Business Media LLC
Date: 12-2015
Intrinsic factors drive spatial genetic variation in a highly vagile species, the wedge‐tailed eagle Aquila audax, in Tasmania
Publisher: Wiley
Date: 10-05-2017
DOI: 10.1111/JAV.01326
Fine-temporal forecasting of outbreak probability and severity: Ross River virus in Western Australia
Publisher: Cambridge University Press (CUP)
Date: 04-09-2017
DOI: 10.1017/S095026881700190X
Abstract: Health warnings of mosquito-borne disease risk require forecasts that are accurate at fine-temporal resolutions (weekly scales) however, most forecasting is coarse (monthly). We use environmental and Ross River virus (RRV) surveillance to predict weekly outbreak probabilities and incidence spanning tropical, semi-arid, and Mediterranean regions of Western Australia (1991–2014). Hurdle and linear models were used to predict outbreak probabilities and incidence respectively, using time-lagged environmental variables. Forecast accuracy was assessed by model fit and cross-validation. Residual RRV notification data were also examined against mitigation expenditure for one site, Mandurah 2007–2014. Models were predictive of RRV activity, except at one site (Capel). Minimum temperature was an important predictor of RRV outbreaks and incidence at all predicted sites. Precipitation was more likely to cause outbreaks and greater incidence among tropical and semi-arid sites. While variable, mitigation expenditure coincided positively with increased RRV incidence ( r 2 = 0·21). Our research demonstrates capacity to accurately predict mosquito-borne disease outbreaks and incidence at fine-temporal resolutions. We apply our findings, developing a user-friendly tool enabling managers to easily adopt this research to forecast region-specific RRV outbreaks and incidence. Approaches here may be of value to fine-scale forecasting of RRV in other areas of Australia, and other mosquito-borne diseases.
The spectral underpinnings of pathogen spread on animal networks
Publisher: The Royal Society
Date: 20-09-2023
When are pathogen dynamics likely to reflect host population genetic structure?
Publisher: Wiley
Date: 28-02-2020
DOI: 10.1111/MEC.15379
Time to consider pharmacological interventions against infectious disease in wildlife
Publisher: Wiley
Date: 24-11-2023
Abstract: Interventions against infectious diseases in wildlife are increasingly necessary but remain problematic. Dissimilar to public and domestic animal health, pharmacological interventions (PIs) are rarely used against disease in wildlife populations. However, drugs can combat a range of pathogen types while aligning with positive ethical, epidemiological, evolutionary and socio‐economic outcomes. We discuss how recent conceptual and technological advances could overcome barriers, improve safety and begin a new era of contemporary wildlife management that embraces PIs. We then provide a framework that supports an objective comparison of intervention suitability, including PIs. We find numerous directions for PI optimisation through innovation and transdisciplinary collaboration and demonstrate the utility of the framework for judging the appropriateness of a PI. Synthesis and applications : Interrogating how and when pharmacological interventions can be used to the greatest effect reduces risks and improves outcomes for wildlife, while empowering decision makers to draw from the full suite of intervention methods to find the most appropriate disease management solutions.
Environmental monitoring to enhance comprehension and control of infectious diseases
Publisher: Royal Society of Chemistry (RSC)
Date: 2010
DOI: 10.1039/C0EM00046A
The relative contribution of causal factors in the transition from infection to clinical chlamydial disease
Publisher: Springer Science and Business Media LLC
Date: 11-06-2018
DOI: 10.1038/S41598-018-27253-Z
Abstract: Chlamydia is a major bacterial pathogen in humans and animals globally. Yet 80% of infections never progress to clinical disease. Decades of research have generated an interconnected network linking pathogen, host, and environmental factors to disease expression, but the relative importance of these and whether they account for disease progression remains unknown. To address this, we used structural equation modeling to evaluate putative factors likely to contribute to urogenital and ocular chlamydial disease in the koala ( Phascolarctos cinereus ). These factors include Chlamydia detection, load, and ompA genotype urogenital and ocular microbiomes host sex, age, weight, body condition breading season, time of year location retrovirus co-infection and major histocompatibility complex class II (MHCII) alleles. We show different microbiological processes underpin disease progression at urogenital and ocular sites. From each category of factors, urogenital disease was most strongly predicted by chlamydial PCR detection and load, koala body condition and environmental location. In contrast, ocular disease was most strongly predicted by phylum-level Chlamydiae microbiome proportions, s ling during breeding season and co-infection with koala retrovirus subtype B. Host MHCII alleles also contributed predictive power to both disease models. Our results also show considerable uncertainty remains, suggesting major causal mechanisms are yet to be discovered.
Pharmacokinetic and pharmacodynamic considerations for treating sarcoptic mange with cross-relevance to Australian wildlife
Publisher: Elsevier BV
Date: 04-2023
Pathogen exposure varies widely among sympatric populations of wild and domestic felids across the United States
Publisher: Wiley
Date: 03-2016
DOI: 10.1890/15-0445
Abstract: Understanding how landscape, host, and pathogen traits contribute to disease exposure requires systematic evaluations of pathogens within and among host species and geographic regions. The relative importance of these attributes is critical for management of wildlife and mitigating domestic animal and human disease, particularly given rapid ecological changes, such as urbanization. We screened > 1000 s les from sympatric populations of puma (Puma concolor), bobcat (Lynx rufus), and domestic cat (Felis catus) across urban gradients in six sites, representing three regions, in North America for exposure to a representative suite of bacterial, protozoal, and viral pathogens (Bartonella sp., Toxoplasma gondii, feline herpesvirus-1, feline panleukopenea virus, feline calicivirus, and feline immunodeficiency virus). We evaluated prevalence within each species, and examined host trait and land cover determinants of exposure providing an unprecedented analysis of factors relating to potential for infections in domesticated and wild felids. Prevalence differed among host species (highest for puma and lowest for domestic cat) and was greater for indirectly transmitted pathogens. Sex was inconsistently predictive of exposure to directly transmitted pathogens only, and age infrequently predictive of both direct and indirectly transmitted pathogens. Determinants of pathogen exposure were widely ergent between the wild felid species. For puma, suburban land use predicted increased exposure to Bartonella sp. in southern California, and FHV-1 exposure increased near urban edges in Florida. This may suggest interspecific transmission with domestic cats via flea vectors (California) and direct contact (Florida) around urban boundaries. Bobcats captured near urban areas had increased exposure to T. gondii in Florida, suggesting an urban source of prey Bobcats captured near urban areas in Colorado and Florida had higher FIV exposure, possibly suggesting increased intraspecific interactions through pile-up of home ranges. Beyond these regional and pathogen specific relationships, proximity to the wildland-urban interface did not generally increase the probability of disease exposure in wild or domestic felids, empha- sizing the importance of local ecological determinants. Indeed, pathogen exposure was often negatively associated with the wildland-urban interface for all felids. Our analyses suggest cross-species pathogen transmission events around this interface may be infrequent, but followed by self-sustaining propagation within the new host species. virus puma (Puma concolor) Toxoplasma gondii urbanization.
Feline Leukemia Virus (FeLV) Disease Outcomes in a Domestic Cat Breeding Colony: Relationship to Endogenous FeLV and Other Chronic Viral Infections
Publisher: American Society for Microbiology
Date: 15-09-2018
DOI: 10.1128/JVI.00649-18
Abstract: Endogenous retroviruses are harbored by many animals, and their interactions with exogenous retroviral infections have not been widely studied. Feline leukemia virus (FeLV) is a relevant model system to examine this question, as endogenous and exogenous forms of the virus exist. In this analysis of a large domestic cat breeding colony naturally infected with FeLV, we documented that enFeLV copy number was higher in males and inversely related to FeLV viral load and associated with better FeLV disease outcomes. Females had lower enFeLV copy numbers and were more likely to have progressive FeLV disease and FeLV-B subtypes. FFV viral load was correlated with FeLV progression. FFV, FcaGHV-1, and FeLV displayed markedly different patterns of infection with respect to host demographics. This investigation revealed complex coinfection outcomes and viral ecology of chronic infections in a closed population.
The Roles of Predators, Competitors, and Secondary Salinization in Structuring Mosquito (Diptera: Culicidae) Assemblages in Ephemeral Water Bodies of the Wheatbelt of Western Australia
Publisher: Oxford University Press (OUP)
Date: 06-2010
DOI: 10.1603/EN09235
The effect of spatial dynamics on the behaviour of an environmentally transmitted disease
Publisher: Informa UK Limited
Date: 11-04-2022
DOI: 10.1080/17513758.2022.2061614
Abstract: Understanding the spread of pathogens through the environment is critical to a fuller comprehension of disease dynamics. However, many mathematical models of disease dynamics ignore spatial effects. We seek to expand knowledge around the interaction between the bare-nosed wombat (
Salinity tolerance of Aedes camptorhynchus (Diptera: Culicidae) from two regions in southwestern Australia
Publisher: Wiley
Date: 11-2009
Proceedings of the society for research on Amphibians and Reptiles in New Zealand
Publisher: Informa UK Limited
Date: 2005
Capturing Complex Vaccine-Immune-Disease Relationships for Free-Ranging Koalas: Higher Chlamydial Loads Are Associated With Less IL17 Expression and More Chlamydial Disease
Publisher: Frontiers Media SA
Date: 25-09-2020
Does the virus cross the road? Viral phylogeographic patterns among bobcat populations reflect a history of urban development
Publisher: Wiley
Date: 20-02-2020
DOI: 10.1111/EVA.12927
Novel gammaherpesviruses in North American domestic cats, bobcats, and pumas: identification, prevalence, and risk factors.
Publisher: American Society for Microbiology
Date: 15-04-2014
DOI: 10.1128/JVI.03405-13
Abstract: Gammaherpesviruses (GHVs) are a erse and rapidly expanding group of viruses associated with a variety of disease conditions in humans and animals. To identify felid GHVs, we screened domestic cat ( Felis catus ), bobcat ( Lynx rufus ), and puma ( Puma concolor ) blood cell DNA s les from California, Colorado, and Florida using a degenerate pan-GHV PCR. Additional pan-GHV and long-distance PCRs were used to sequence a contiguous 3.4-kb region of each putative virus species, including partial glycoprotein B and DNA polymerase genes. We identified three novel GHVs, each present predominantly in one felid species: Felis catus GHV 1 (FcaGHV1) in domestic cats, Lynx rufus GHV 1 (LruGHV1) in bobcats, and Puma concolor GHV 1 (PcoGHV1) in pumas. To estimate infection prevalence, we developed real-time quantitative PCR assays for each virus and screened additional DNA s les from all three species ( n = 282). FcaGHV1 was detected in 16% of domestic cats across all study sites. LruGHV1 was detected in 47% of bobcats and 13% of pumas across all study sites, suggesting relatively common interspecific transmission. PcoGHV1 was detected in 6% of pumas, all from a specific region of Southern California. The risk of infection for each host varied with geographic location. Age was a positive risk factor for bobcat LruGHV1 infection, and age and being male were risk factors for domestic cat FcaGHV1 infection. Further characterization of these viruses may have significant health implications for domestic cats and may aid studies of free-ranging felid ecology. IMPORTANCE Gammaherpesviruses (GHVs) establish lifelong infection in many animal species and can cause cancer and other diseases in humans and animals. In this study, we identified the DNA sequences of three GHVs present in the blood of domestic cats ( Felis catus ), bobcats ( Lynx rufus ), and pumas ( Puma concolor also known as mountain lions, cougars, and panthers). We found that these viruses were closely related to, but distinct from, other known GHVs of animals and represent the first GHVs identified to be native to these feline species. We developed techniques to rapidly and specifically detect the DNA of these viruses in feline blood and found that the domestic cat and bobcat viruses were widespread across the United States. In contrast, puma virus was found only in a specific region of Southern California. Surprisingly, the bobcat virus was also detected in some pumas, suggesting relatively common virus transmission between these species. Adult domestic cats and bobcats were at greater risk for infection than juveniles. Male domestic cats were at greater risk for infection than females. This study identifies three new viruses that are widespread in three feline species, indicates risk factors for infection that may relate to the route of infection, and demonstrates cross-species transmission between bobcats and pumas. These newly identified viruses may have important effects on feline health and ecology.
Felis catus gammaherpesvirus 1; a widely endemic potential pathogen of domestic cats.
Publisher: Elsevier BV
Date: 07-2014
DOI: 10.1016/J.VIROL.2014.05.007
Abstract: Felis catus gammaherpesvirus 1 (FcaGHV1), recently discovered in the USA, was detected in domestic cats in Australia (11.4%, 95% confidence interval 5.9-19.1, n=110) and Singapore (9.6%, 95% confidence interval 5.9-14.6, n=176) using qPCR. FcaGHV1 qPCR positive cats were 2.8 times more likely to be sick than healthy. Risk factors for FcaGHV1 detection included being male, increasing age and coinfection with pathogenic retroviruses, feline immunodeficiency virus (FIV) or feline leukaemia virus. FcaGHV1 DNA was detected in multiple tissues from infected cats with consistently high virus loads in the small intestine. FcaGHV1 viral load was significantly higher in FIV-infected cats compared with matched controls, mimicking increased Epstein-Barr virus loads in human immunodeficiency virus-infected humans. FcaGHV1 is endemic in distant geographic regions and is associated with being sick and with coinfections. Horizontal transmission of FcaGHV1 is supported, with biting being a plausible route. A pathogenic role for FcaGHV1 in domestic cats is supported.
Dryland Salinity and Ecosystem Distress Syndrome: Human Health Implications
Publisher: Springer Science and Business Media LLC
Date: 13-02-2007
Outdoor Recreation at the Wildland—Urban Interface: Examining Human Activity Patterns and Compliance with Dog Management Policies
Publisher: Natural Areas Journal
Date: 10-2017
DOI: 10.3375/043.037.0408
Feline immunodeficiency virus in puma: Estimation of force of infection reveals insights into transmission
Publisher: Wiley
Date: 26-09-2019
DOI: 10.1002/ECE3.5584
Does Chytridiomycosis Disrupt Amphibian Skin Function?
Publisher: American Society of Ichthyologists and Herpetologists (ASIH)
Date: 09-2010
DOI: 10.1643/CH-09-128
Combination Antiretroviral Therapy and Immunophenotype of Feline Immunodeficiency Virus
Publisher: MDPI AG
Date: 24-03-2023
DOI: 10.3390/V15040822
Abstract: Feline Immunodeficiency Virus (FIV) causes progressive immune dysfunction in cats similar to human immunodeficiency virus (HIV) in humans. Although combination antiretroviral therapy (cART) is effective against HIV, there is no definitive therapy to improve clinical outcomes in cats with FIV. This study therefore evaluated pharmacokinetics and clinical outcomes of cART (2.5 mg/kg Dolutegravir 20 mg/kg Tenofovir 40 mg/kg Emtricitabine) in FIV-infected domestic cats. Specific pathogen free cats were experimentally infected with FIV and administered either cART or placebo treatments (n = 6 each) for 18 weeks, while n = 6 naïve uninfected cats served as controls. Blood, saliva, and fine needle aspirates from mandibular lymph nodes were collected to quantify viral and proviral loads via digital droplet PCR and to assess lymphocyte immunophenotypes by flow cytometry. cART improved blood dyscrasias in FIV-infected cats, which normalized by week 16, while placebo cats remained neutropenic, although no significant difference in viremia was observed in the blood or saliva. cART-treated cats exhibited a Th2 immunophenotype with increasing proportions of CD4+CCR4+ cells compared to placebo cats, and cART restored Th17 cells compared to placebo-treated cats. Of the cART drugs, dolutegravir was the most stable and long-lasting. These findings provide a critical insight into novel cART formulations in FIV-infected cats and highlight their role as a potential animal model to evaluate the impact of cART on lentiviral infection and immune dysregulation.
House mouse abundance and Ross River virus notifications in Victoria, Australia
Publisher: Elsevier BV
Date: 09-2008
DOI: 10.1016/J.IJID.2008.02.008
Abstract: The number of emerging and re-emerging infectious diseases is increasing. As such, understanding the fundamental ecology of infectious disease is critical. Short-lived highly fecund lification hosts are implicated to influence disease prevalence, but few empirical ex les exist. We examined the relationship between mouse (Mus musculus) abundance and Ross River virus (RRV) incidence in northwest Victoria, Australia. We determined a biologically plausible distribution overlap of M. musculus, humans, and vector mosquitoes in our study region. We compared M. musculus abundance with human RRV notifications seasonally between 1997 and 2000. Trends in M. musculus and RRV were similar during summer, autumn, and summer plus autumn, but unrelated during winter, spring, and winter plus spring, coinciding with the seasonal abundance and relative absence of the vector, Culex annulirostris. Our results demonstrate a plausible association between M. musculus and RRV incidence, suggesting that short-lived highly fecund lification hosts may profoundly influence disease transmission. Our results are supported by theoretical studies and empirical evidence from other systems. Further research is warranted to establish a causal relationship between lification hosts and RRV, and in other infectious disease systems. Implications for the management of infectious disease may exist.
Pathogenesis of oral FIV infection
Publisher: Public Library of Science (PLoS)
Date: 21-09-2017
The effects of demographic, social, and environmental characteristics on pathogen prevalence in wild felids across a gradient of urbanization
Publisher: Public Library of Science (PLoS)
Date: 09-11-2017
Dryland Salinity and Human Health Outcomes
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 11-2006
Healthy wetlands, healthy people: Mosquito borne disease
Publisher: Springer Netherlands
Date: 2015
Domestic cat microsphere immunoassays: Detection of antibodies during feline immunodeficiency virus infection
Publisher: Elsevier BV
Date: 10-2013
Population‐scale treatment informs solutions for control of environmentally transmitted wildlife disease
Publisher: Wiley
Date: 23-07-2019
Abstract: Long‐term pathogen control or eradication in wildlife is rare and represents a major challenge in conservation. Control is particularly difficult for environmentally transmitted pathogens, including some of the most conservation‐critical wildlife diseases. We undertook a treatment programme aimed at population‐scale eradication of the environmentally transmitted Sarcoptes scabiei mite (causative agent of sarcoptic mange) during an epizootic in bare‐nosed wombats ( Vombatus ursinus ). Field trial results were used to parameterize a mechanistic host‐disease model that explicitly described indirect transmission, host behaviour and viable disease intervention methods. Model analysis shows that elimination of S. scabiei in the wild is most sensitive to the success of treatment delivery, and duration of the programme. In addition, we found the frequency that wombats switch burrows was an important positive driver of mite persistence. Synthesis and applications . This research emphasizes the utility of applying model‐guided management techniques in order to achieve practical solutions for controlling disease in the field. We find that control efforts of Sarcoptes scabiei are most successful when simultaneous improvements are made to the current best‐practice protocol, specifically the implementation of better treatment application methods in combination with a longer lasting treatment. These suggested management changes may also reduce the resources and field effort required to implement a successful regime. Furthermore, our approach and findings have applicability to other species affected by S. scabiei (e.g. wolves, red foxes, Spanish ibex and American black bear), as well as other conservation‐critical systems involving environmental transmission (e.g. bat white‐nose syndrome and hibian chytridiomycosis).
Temporal patterns and environmental correlates of macroinvertebrate communities in temporary streams
Publisher: Public Library of Science (PLoS)
Date: 10-11-2015
Post-fire habitat use of the golden-backed tree-rat (Mesembriomys macrurus) in the northwest Kimberley, Western Australia
Publisher: Wiley
Date: 14-07-2015
DOI: 10.1111/AEC.12278
Toward a Mechanistic Understanding of Environmentally Forced Zoonotic Disease Emergence: Sin Nombre Hantavirus
Publisher: Oxford University Press (OUP)
Date: 05-2015
DELAYED DENSITY-DEPENDENT PREVALENCE OF SIN NOMBRE VIRUS INFECTION IN DEER MICE (PEROMYSCUS MANICULATUS) IN CENTRAL AND WESTERN MONTANA
Publisher: Wildlife Disease Association
Date: 2011
Post release immune responses of Tasmanian devils vaccinated with an experimental devil facial tumour disease vaccine
Publisher: Cold Spring Harbor Laboratory
Date: 07-12-2020
DOI: 10.1101/2020.12.06.408963
Abstract: Disease is increasingly becoming a driver of wildlife population declines and extinction risk. Vaccines have been one of the most successful health interventions in human history, but few have been tested for mitigating wildlife disease. The transmissible cancer, devil facial tumour disease (DFTD), triggered the Tasmanian devil’s ( Sarcophilus harrisii ) inclusion on the international endangered species list. Development of a protective DFTD vaccine would provide a valuable management approach for conservation of the species. In 2016, 33 devils from a DFTD-free insurance population were given an experimental DFTD vaccination prior to their release on the north coast of Tasmania. The release site was already home to an incumbent population of devils, including some in iduals with DFTD. To determine the efficacy of the vaccination protocol and the longevity of the response it induced, six trapping trips took place at the site over the 2.5 years following release. Eight of the 33 vaccinated devils were re-trapped, and six of those developed DFTD within the monitoring period. Despite the apparent lack of protection provided by the vaccine for the re-trapped devils, we observed several signs of immune activation not usually found in unvaccinated devils. Firstly, sera collected from the eight devils showed that anti-DFTD antibodies persisted for up to two years post vaccination. Secondly, tumour infiltrating lymphocytes were found in three out of four biopsies collected from vaccinated devils which contrasts with the “immune deserts” typical of DFT’s only one out of twenty incumbent devils with DFTD trapped during the same period had a tumour biopsy exhibiting immune cell infiltrate. Thirdly, immunohistochemical analysis of tumour biopsies from the vaccinated devils identified the functional immune molecules associated with antigen presenting cells (MHC-II) and T cells (CD3), and the immune checkpoint molecule PD-1, all associated with anti-tumour immunity in other species. These results correlate with our previous study on captive devils in which a prophylactic vaccine primed the devil immune system and, following DFTD challenge and tumour growth, immunotherapy induced complete tumour regressions. The field trial results presented here provide further evidence that the devil immune system can be primed to recognise DFTD cells, but additional immune manipulation could be needed for complete protection or induction of tumour regressions.
A Solutions-Focused Translational Research Framework for Wildlife Health
Publisher: Oxford University Press (OUP)
Date: 13-11-2019
Abstract: Wildlife health is of emerging relevance for conservation, human health, and domestic animal health. Increased research on wildlife health problems has not been accompanied by a relative increase in effective solutions. Translational research was developed in human health to overcome blocks impeding the development of solutions out of basic research, and a translational research framework is proposed to overcome the same barriers in wildlife health. This framework has four translational phases: problem definition, potential solution development, efficacious solution development, and effective solution development. Implementation of translational research will require a restructuring of the wildlife health research enterprise with a shift, supported by funding sources and journals, to solutions-focused research including later translational phases, the creation of more deeply integrated multidisciplinary and interdisciplinary teams incorporating better representation from human social sciences, and the inclusion of end user and stakeholder participation in all phases of research.
Characterizing the spatio-temporal threats, conservation hotspots and conservation gaps for the most extinction-prone bird family (Aves: Rallidae)
Publisher: The Royal Society
Date: 09-2021
DOI: 10.1098/RSOS.210262
Abstract: With thousands of vertebrate species now threatened with extinction, there is an urgent need to understand and mitigate the causes of wildlife collapse. Rails (Aves: Rallidae), being the most extinction-prone bird family globally, and with one-third of extant rail species now threatened or near threatened, are an emphatic case in point. Here, we undertook a global synthesis of the temporal and spatial threat patterns for Rallidae and determined conservation priorities and gaps. We found two key pathways in the threat pattern for rails. One follows the same trajectory as extinct rails, where island endemic and flightless rails are most threatened, mainly due to invasive predators. The second, created by the ersification of anthropogenic activities, involves continental rails, threatened mainly by agriculture, natural system modifications, and residential and commercial development. Indonesia, the USA, the United Kingdom, New Zealand and Cuba were the priority countries identified by our framework incorporating species' uniqueness and the level of endangerment, but also among the countries that lack conservation actions the most. Future efforts should predominantly target improvements in ecosystem protection and management, as well as ongoing research and monitoring. Forecasting the impacts of climate change on island endemic rails will be particularly valuable to protect rails.
The Patterns and Causes of Dermatitis in Terrestrial and Semi-Aquatic Mammalian Wildlife
Publisher: MDPI AG
Date: 06-06-2021
DOI: 10.3390/ANI11061691
Abstract: Causative disease and stress agents which manifest as dermatitis in mammals have varying effects on in idual animals, from benign irritation and inflammation, to causing morbidity and even mortality. Bacteria, viruses and ectoparasites are all potential causes of dermatitis, and it can be exacerbated by various environmental, genetic and social factors. Furthermore, it is uncertain whether dermatitis is more likely to manifest in already-vulnerable wildlife species. Here, we systematically review the literature for reports of dermatitis in terrestrial and semi-aquatic wild mammalian species, with the goal of determining the biogeographical scale of dermatitis reports, the causes of dermatitis, and whether manifestation of dermatitis is reported more commonly in certain wildlife species or their captivity status (i.e., free-living, in captivity or in a laboratory). We reveal biases in the reporting of dermatitis by a biogeographic realm, with 55% of cases reported in the Nearctic, and towards particular orders of mammals, namely Artiodactyla and Carnivora. Overall, free-living wildlife is almost twice as likely to be reported as having dermatitis than in iduals in captivity and six times more likely than in iduals in laboratories, which we interpret as owing to exposure to a broader spectrum of parasites in free-ranging in iduals, and potential reporting bias in captive in iduals. Notably, dermatitis was reported in 23 threatened species, with some species more likely than others to be reported exhibiting clinical signs of dermatitis resulting from underlying health problems. We also find that threatened species are more likely to be reported as having dermatitis in captivity, particularly outside of their endemic home range. This review highlights erse patterns of dermatological disease causes in captive and free-ranging wildlife, conditions under which they are more likely to be documented, and the need for cross-disciplinary research to ascertain (and so better manage) the varied causes.
The impacts of timber harvesting on stream biota – An expanding field of heterogeneity
Publisher: Elsevier BV
Date: 09-2017
Mosquito eradication: the story of killing campto
Publisher: Informa UK Limited
Date: 26-03-2015
Host relatedness and landscape connectivity shape pathogen spread in the puma, a large secretive carnivore
Publisher: Springer Science and Business Media LLC
Date: 04-01-2021
DOI: 10.1038/S42003-020-01548-2
Abstract: Urban expansion can fundamentally alter wildlife movement and gene flow, but how urbanization alters pathogen spread is poorly understood. Here, we combine high resolution host and viral genomic data with landscape variables to examine the context of viral spread in puma ( Puma concolor ) from two contrasting regions: one bounded by the wildland urban interface (WUI) and one unbounded with minimal anthropogenic development (UB). We found landscape variables and host gene flow explained significant amounts of variation of feline immunodeficiency virus (FIV) spread in the WUI, but not in the unbounded region. The most important predictors of viral spread also differed host spatial proximity, host relatedness, and mountain ranges played a role in FIV spread in the WUI, whereas roads might have facilitated viral spread in the unbounded region. Our research demonstrates how anthropogenic landscapes can alter pathogen spread, providing a more nuanced understanding of host-pathogen relationships to inform disease ecology in free-ranging species.
Variation in Intra-individual Lentiviral Evolution Rates: a Systematic Review of Human, Nonhuman Primate, and Felid Species
Publisher: American Society for Microbiology
Date: 15-08-2019
DOI: 10.1128/JVI.00538-19
Abstract: To the best of our knowledge, this is the first study that compares intra-in idual evolution rates for FIV, SIV, and HIV following systematic review of the literature. Our findings have important implications for informing research strategies in the field of intra-in idual virus dynamics for lentiviruses. We observed that FIV evolves more slowly than HIV and SIV at the intra-in idual level and found that mutation rates may differ by gene sequence length but not by host, gene, strain, an experimental setting relative to a natural setting, or spillover host infection relative to primary host infection.
Canine distemper in Nepal's Annapurna Conservation Area – Implications of dog husbandry and human behaviour for wildlife disease
Publisher: Public Library of Science (PLoS)
Date: 05-12-2019
Detection of Chronic Wasting Disease Prions in Salivary, Urinary, and Intestinal Tissues of Deer: Potential Mechanisms of Prion Shedding and Transmission
Publisher: American Society for Microbiology
Date: 07-2011
DOI: 10.1128/JVI.00425-11
Abstract: Efficient horizontal transmission is a signature trait of chronic wasting disease (CWD) in cervids. Infectious prions shed into excreta appear to play a key role in this facile transmission, as has been demonstrated by bioassays of cervid and transgenic species and serial protein misfolding cyclic lification (sPMCA). However, the source(s) of infectious prions in these body fluids has yet to be identified. In the present study, we analyzed tissues proximate to saliva, urine, and fecal production by sPMCA in an attempt to elucidate this unique aspect of CWD pathogenesis. Oropharyngeal, urogenital, and gastrointestinal tissues along with blood and obex from CWD-exposed cervids (comprising 27 animals and in idual s les) were analyzed and scored based on the apparent relative CWD burden. PrP CWD -generating activity was detected in a range of tissues and was highest in the salivary gland, urinary bladder, and distal intestinal tract. In the same assays, blood from the same animals and unseeded normal brain homogenate controls ( n = 116 of 117) remained negative. The PrP-converting activity in peripheral tissues varied from 10 −11 - to 10 0 -fold of that found in brain of the same animal. Deer with highest levels of PrP CWD lification in the brain had higher and more widely disseminated prion lification in excretory tissues. Interestingly, PrP CWD was not demonstrable in these excretory tissues by conventional Western blotting, suggesting a low prion burden or the presence of protease-sensitive infectious prions destroyed by harsh proteolytic treatments. These findings offer unique insights into the transmission of CWD in particular and prion infection and trafficking overall.
Environmental drivers of Ross River virus in southeastern Tasmania, Australia: towards strengthening public health interventions
Publisher: Cambridge University Press (CUP)
Date: 25-03-2011
DOI: 10.1017/S0950268811000446
Abstract: In Australia, Ross River virus (RRV) is predominantly identified and managed through passive health surveillance. Here, the proactive use of environmental datasets to improve community-scale public health interventions in southeastern Tasmania is explored. Known environmental drivers (temperature, rainfall, tide) of the RRV vector Aedes c torhynchus are analysed against cumulative case records for five adjacent local government areas (LGAs) from 1993 to 2009. Allowing for a 0- to 3-month lag period, temperature was the most significant driver of RRV cases at 1-month lag, contributing to a 23·2% increase in cases above the long-term case average. The potential for RRV to become an emerging public health issue in Tasmania due to projected climate changes is discussed. Moreover, practical outputs from this research are proposed including the development of an early warning system for local councils to implement preventative measures, such as public outreach and mosquito spray programmes.
The Koala, an Iconic Animal under Threat
Publisher: Wildlife Disease Association
Date: 28-04-2016
DOI: 10.7589/52-02-39
Assessing Variation in the Individual-Level Impacts of a Multihost Pathogen
Publisher: Hindawi Limited
Date: 27-05-2023
DOI: 10.1155/2023/4003285
Abstract: Most pathogens infect more than one host species, and given infection, the in idual-level impact they have varies among host species. Nevertheless, variation in in idual-level impacts of infection remains poorly characterised. Using the impactful and host-generalist ectoparasitic mite Sarcoptes scabiei (causing sarcoptic mange), we assessed in idual-level variation in pathogen impacts by (1) compiling all documented in idual-level impacts of S. scabiei across free-living host species, (2) quantifying and ranking S. scabiei impacts among host species, and (3) evaluating factors associated with S. scabiei impacts. We compiled in idual-level impacts of S. scabiei infection from 77 host species, spanning 31 different impacts, and totalling 683 in idual-level impact descriptions. The most common impacts were those affecting the skin, alopecia (130 descriptions), and hyperkeratosis coverage (106). From these impacts, a standardised metric was generated for each species (average impact score (AIS) with a 0-1 range), as a proxy of pathogen virulence allowing quantitative comparison of S. scabiei impacts among host species while accounting for the variation in the number and types of impacts assessed. The Japanese raccoon dog (Nyctereutes viverrinus) was found to be the most impacted host (AIS 0.899). We applied species inclusion criteria for ranking and found more well-studied species tended to be those impacted more by S. scabiei (26/27 species AIS 0.5). AIS had relatively weak relationships with predictor variables (methodological, phylogenetic, and geographic). There was a tendency for Diprotodontia, Artiodactyla, and Carnivora to be the most impacted taxa and for research to be focussed in developed regions of the world. This study is the first quantitative assessment of in idual-level pathogen impacts of a multihost parasite. The proposed methodology can be applied to other multihost pathogens of public health, animal welfare, and conservation concern and enables further research to address likely causes of variation in pathogen virulence among host species.
Fine-Scale Landscape Epidemiology: Sarcoptic Mange in Bare-Nosed Wombats (Vombatus ursinus)
Publisher: Hindawi Limited
Date: 04-03-2023
DOI: 10.1155/2023/2955321
Abstract: Landscape epidemiology provides a valuable framework to interpret, predict, and manage spatiotemporal patterns of disease. Yet, owing to the difficulty of detecting pathogen occurrence in free-ranging wildlife, disentangling the factors driving disease dynamics remains a considerable challenge, particularly at fine spatial scales. Here, we investigated the fine-scale landscape epidemiology of sarcoptic mange—a visually apparent disease caused by the mite Sarcoptes scabiei—in bare-nosed wombats (Vombatus ursinus), by: (1) characterizing the distribution and density of wombats within the landscape and (2) examining the effect of environmental variation on the occurrence and apparent prevalence of mange. Wombats were heterogeneously distributed over 19.4 km of transect space (0.096–1.39 wombats ha−1) and seven months of time (increasing by a factor of 1.76). Wombat density was negatively associated with distance to vegetation cover, supporting a general propensity for wombats to occur and burrow near vegetation (native and exotic, excluding pasture). The apparent prevalence of mange varied spatially (3.1–37.5%), with the probability of disease greater in wombats with minimal vegetation and low-lying pans in their estimated home range. We observed trends of increased prevalence in areas with more burrows available per wombat and in in iduals occurring near vegetation cover (although not within their home range). Wombat density and active burrow density did not influence the prevalence of mange. This research emphasizes the fine scale at which spatiotemporal patterns of disease can manifest and is the first to investigate the influence of host density for any species with indirect transmission of S. scabiei. Collectively, our results suggest that in iduals inhabiting less optimal habitat (pasture) may be at greater risk of disease, or that diseased wombats may be competitively excluded from more optimal habitat (vegetated areas). We discuss implications for understanding and managing mange in wombats and cross-applicability to other mange-affected species with environmental transmission.
Drying dynamics of pellet feces
Publisher: Royal Society of Chemistry (RSC)
Date: 2023
DOI: 10.1039/D2SM00359G
Abstract: Pellet feces are generated by a number of animals important to science or agriculture, including mice, rats, goats, and wombats.
Sustaining Transmission in Different Host Species: The Emblematic Case ofSarcoptes scabiei
Publisher: Oxford University Press (OUP)
Date: 27-10-2021
Abstract: Some pathogens sustain transmission in multiple different host species, but how this epidemiologically important feat is achieved remains enigmatic. Sarcoptes scabiei is among the most host generalist and successful of mammalian parasites. We synthesize pathogen and host traits that mediate sustained transmission and present cases illustrating three transmission mechanisms (direct, indirect, and combined). The pathogen traits that explain the success of S. scabiei include immune response modulation, on-host movement capacity, off-host seeking behaviors, and environmental persistence. Sociality and host density appear to be key for hosts in which direct transmission dominates, whereas in solitary hosts, the use of shared environments is important for indirect transmission. In social den-using species, combined direct and indirect transmission appears likely. Empirical research rarely considers the mechanisms enabling S. scabiei to become endemic in host species—more often focusing on outbreaks. Our review may illuminate parasites’ adaptation strategies to sustain transmission through varied mechanisms across host species.
Changes in spatial organization following an acute epizootic: Tasmanian devils and their transmissible cancer
Publisher: Elsevier BV
Date: 06-2020
Frequent cross-species transmissions of foamy virus between domestic and wild felids
Publisher: Oxford University Press (OUP)
Date: 2020
DOI: 10.1093/VE/VEZ058
Abstract: Emerging viral outbreaks resulting from host switching is an area of continued scientific interest. Such events can result in disease epidemics or in some cases, clinically silent outcomes. These occurrences are likely relatively common and can serve as tools to better understand disease dynamics, and may result in changes in behavior, fecundity, and, ultimately survival of the host. Feline foamy virus (FFV) is a common retrovirus infecting domestic cats globally, which has also been documented in the North American puma (Puma concolor). The prevalent nature of FFV in domestic cats and its ability to infect wild felids, including puma, provides an ideal system to study cross-species transmission across trophic levels (positions in the food chain), and evolution of pathogens transmitted between in iduals following direct contact. Here we present findings from an extensive molecular analysis of FFV in pumas, focused on two locations in Colorado, and in relation to FFV recovered from domestic cats in this and previous studies. Prevalence of FFV in puma was high across the two regions, ∼77 per cent (urban interface site) and ∼48 per cent (rural site). Comparison of FFV from pumas living across three states Colorado, Florida, and California, indicates FFV is widely distributed across North America. FFV isolated from domestic cats and pumas was not distinguishable at the host level, with FFV sequences sharing & per cent nucleotide similarity. Phylogenetic, Bayesian, and recombination analyses of FFV across the two species supports frequent cross-species spillover from domestic cat to puma during the last century, as well as frequent puma-to-puma intraspecific transmission in Colorado, USA. Two FFV variants, distinguished by significant difference in the surface unit of the envelope protein, were commonly found in both hosts. This trait is also shared by simian foamy virus and may represent variation in cell tropism or a unique immune evasion mechanism. This study elucidates evolutionary and cross-species transmission dynamics of a highly prevalent multi-host adapted virus, a system which can further be applied to model spillover and transmission of pathogenic viruses resulting in widespread infection in the new host.
A secure future? Human urban and agricultural land use benefits a flightless island-endemic rail despite climate change
Publisher: The Royal Society
Date: 06-2023
DOI: 10.1098/RSOS.230386
Abstract: Identifying environmental characteristics that limit species' distributions is important for contemporary conservation and inferring responses to future environmental change. The Tasmanian native hen is an island endemic flightless rail and a survivor of a prehistoric extirpation event. Little is known about the regional-scale environmental characteristics influencing the distribution of native hens, or how their future distribution might be impacted by environmental shifts (e.g. climate change). Using a combination of local fieldwork and species distribution modelling, we assess environmental factors shaping the contemporary distribution of the native hen, and project future distribution changes under predicted climate change. We find 37% of Tasmania is currently suitable for the native hens, owing to low summer precipitation, low elevation, human-modified vegetation and urban areas. Moreover, in unsuitable regions, urban areas can create ‘oases’ of habitat, able to support populations with high breeding activity by providing resources and buffering against environmental constraints. Under climate change predictions, native hens were predicted to lose only 5% of their occupied range by 2055. We conclude that the species is resilient to climate change and benefits overall from anthropogenic landscape modifications. As such, this constitutes a rare ex le of a flightless rail to have adapted to human activity.
Emerging infectious diseases of wildlife: a critical perspective
Publisher: Elsevier BV
Date: 04-2015
Abstract: We review the literature to distinguish reports of vertebrate wildlife disease emergence with sufficient evidence, enabling a robust assessment of emergence drivers. For potentially emerging agents that cannot be confirmed, sufficient data on prior absence (or a prior difference in disease dynamics) are frequently lacking. Improved surveillance, particularly for neglected host taxa, geographical regions and infectious agents, would enable more effective management should emergence occur. Exposure to domestic sources of infection and human-assisted exposure to wild sources were identified as the two main drivers of emergence across host taxa the domestic source was primary for fish while the wild source was primary for other taxa. There was generally insufficient evidence for major roles of other hypothesized drivers of emergence.
Hunting alters viral transmission and evolution in a large carnivore
Publisher: Springer Science and Business Media LLC
Date: 27-01-2022
DOI: 10.1038/S41559-021-01635-5
Abstract: Hunting can fundamentally alter wildlife population dynamics but the consequences of hunting on pathogen transmission and evolution remain poorly understood. Here, we present a study that leverages a unique landscape-scale quasi-experiment coupled with pathogen-transmission tracing, network simulation and phylodynamics to provide insights into how hunting shapes feline immunodeficiency virus (FIV) dynamics in puma (Puma concolor). We show that removing hunting pressure enhances the role of males in transmission, increases the viral population growth rate and increases the role of evolutionary forces on the pathogen compared to when hunting was reinstated. Changes in transmission observed with the removal of hunting could be linked to short-term social changes while the male puma population increased. These findings are supported through comparison with a region with stable hunting management over the same time period. This study shows that routine wildlife management can have impacts on pathogen transmission and evolution not previously considered.
Feline Foamy Virus is Highly Prevalent in Free-Ranging Puma concolor from Colorado, Florida and Southern California
Publisher: MDPI AG
Date: 19-04-2019
DOI: 10.3390/V11040359
Abstract: Feline foamy virus (FFV) is a retrovirus that has been detected in multiple feline species, including domestic cats (Felis catus) and pumas (Puma concolor). FFV results in persistent infection but is generally thought to be apathogenic. Sero-prevalence in domestic cat populations has been documented in several countries, but the extent of viral infections in nondomestic felids has not been reported. In this study, we screened sera from 348 in idual pumas from Colorado, Southern California and Florida for FFV exposure by assessing sero-reactivity using an FFV anti-Gag ELISA. We documented a sero-prevalence of 78.6% across all s led subpopulations, representing 69.1% in Southern California, 77.3% in Colorado, and 83.5% in Florida. Age was a significant risk factor for FFV infection when analyzing the combined populations. This high prevalence in geographically distinct populations reveals widespread exposure of puma to FFV and suggests efficient shedding and transmission in wild populations.
Habitat connectivity and host relatedness influence virus spread across an urbanising landscape in a fragmentation-sensitive carnivore
Publisher: Oxford University Press (OUP)
Date: 21-12-2022
DOI: 10.1093/VE/VEAC122
Abstract: Spatially heterogeneous landscape factors such as urbanisation can have substantial effects on the severity and spread of wildlife diseases. However, research linking patterns of pathogen transmission to landscape features remains rare. Using a combination of phylogeographic and machine learning approaches, we tested the influence of landscape and host factors on feline immunodeficiency virus (FIVLru) genetic variation and spread among bobcats (Lynx rufus) s led from coastal southern California. We found evidence for increased rates of FIVLru lineage spread through areas of higher vegetation density. Furthermore, single-nucleotide polymorphism (SNP) variation among FIVLru sequences was associated with host genetic distances and geographic location, with FIVLru genetic discontinuities precisely correlating with known urban barriers to host dispersal. An effect of forest land cover on FIVLru SNP variation was likely attributable to host population structure and differences in forest land cover between different populations. Taken together, these results suggest that the spread of FIVLru is constrained by large-scale urban barriers to host movement. Although urbanisation at fine spatial scales did not appear to directly influence virus transmission or spread, we found evidence that viruses transmit and spread more quickly through areas containing higher proportions of natural habitat. These multiple lines of evidence demonstrate how urbanisation can change patterns of contact-dependent pathogen transmission and provide insights into how continued urban development may influence the incidence and management of wildlife disease.
Dryland Salinity and the Ecology of Ross River Virus: The Ecological Underpinnings of the Potential for Transmission
Publisher: Mary Ann Liebert Inc
Date: 12-2009
Abstract: Alterations in transmission of vector-borne zoonoses are often linked to environmental change. However, ecological processes that determine variability in potential for transmission are generally not well understood. Ross River virus (RRV, Togoviridae: Alphavirus) is a mosquito-borne zoonosis in Australia with a significant human disease burden. The inland southwest (Wheatbelt) of Western Australia (WA) is substantially affected by an anthropogenic salinization of agricultural land (dryland salinity). Aedes c torhynchus Thomson (Diptera: Culicidae) is the dominant vector of RRV in southwest WA and is halophilic. As such, dryland salinity may influence potential for RRV transmission by influencing interactions between Ae. c torhynchus and mammalian hosts. We surveyed areas of the Wheatbelt with varying salinity impacts and found Ae. c torhynchus was more abundant in saline areas, whereas sheep Ovis aries (Linnaeus 1758, Bovidae) declined with increasing salinity. We used a deterministic model to examine interactions between Ae. c torhynchus and mammals, and we assessed potential for RRV transmission. We found variation in potential for RRV transmission was positively related to increasing salinity and abundance of Ae. c torhynchus and negatively associated with increasing abundance of Macropus fuliginosus (Desmarest 1817, Macropodidae). Abundance of Ae. c torhynchus determined more variation in potential for RRV transmission than other variables. Accordingly, dryland salinity increases the zoonotic potential for RRV transmission primarily by facilitating abundance of Ae. c torhynchus. Human RRV notifications do not currently reflect the salinity-RRV transmission potential in the Wheatbelt but appear to be associated with RRV activity in the enzootic coastal zone. We speculate dryland salinity is a determinant of potential for RRV transmission but not activity. Dryland salinity is predicted to expand two- to four-fold by 2050. Preservation and restoration of freshwater ecosystems may ameliorate the potential for transmission of RRV and possibly incidence of human disease.
Conservation ecology of Tasmanian coastal saltmarshes, south-east Australia – a review
Publisher: CSIRO Publishing
Date: 2020
DOI: 10.1071/PC19016
Abstract: Temperate Australian saltmarshes, including those in the southern island state of Tasmania, are considered to be a threatened ecological community under Australian federal legislation. There is a need to improve our understanding of the ecological components, functional relationships and threatening processes of Tasmanian coastal saltmarshes and distil research priorities that could assist recovery actions. A semisystematic review of the literature on Tasmanian coastal saltmarshes supported by expert local knowledge identified 75 studies from 1947 to 2019. Existing understanding pertains to saltmarsh plants, soils, invertebrates and human impacts with ongoing studies currently adding to this knowledge base. Several knowledge gaps remain, and the present review recommends six key priority areas for research: (1) citizen science–organised inventory of (initially) saltmarsh birds, plants and human impacts with the potential for expansion of datasets (2) use of saltmarsh by marine transient species including fish and decapods (3) use of saltmarsh by, and interactions with, native and introduced mammals (4) invertebrates and their interactions with predators (e.g. birds, fish) and prey (e.g. insects, plants, detritus) (5) historic saltmarsh loss and priority areas for conservation (6) monitoring changes to saltmarsh due to both localised human impacts (e.g. grazing, eutrophication, destruction) and global change factors (e.g. climate change, sea-level rise). Addressing these research priorities will help in developing a better understanding of the ecological character of Tasmanian coastal saltmarshes and improve their conservation management.
Associations between clinical canine leishmaniosis and multiple vector-borne co-infections: a case-control serological study
Publisher: Springer Science and Business Media LLC
Date: 18-09-2019
DOI: 10.1186/S12917-019-2083-6
Abstract: Dogs that have clinical leishmaniosis (ClinL), caused by the parasite Leishmania infantum , are commonly co-infected with other pathogens, especially vector-borne pathogens (VBP). A recent PCR-based study found that ClinL dogs are more likely to be additionally infected with the rickettsial bacteria Ehrlichia canis . Further information on co-infections in ClinL cases with VBP, as assessed by serology, is required. The research described in this report determined if dogs with ClinL are at higher risk of exposure to VBP than healthy control dogs using a case-control serology study. Of the 47 dogs with ClinL, anti- E. canis / Ehrlichia ewingii antibodies were detected in 17 (36.2%), anti- Anaplasma phagocytophilum / Anaplasma platys antibodies in 5 (10.6%) and antigen for Dirofilaria immitis in 2 (4.3%). Of the 87 control dogs, anti- E. canis / E . ewingii antibodies were detected in 14 (16.1%) and anti- A . phagocytophilum / A . platys antibodies in 2 (2.3%). No anti- Borrelia burgdorferi antibody tests were positive. No statistical differences between the ClinL dogs and control dogs regarding lifestyle or use of ectoparasitic prevention, were identified. The ClinL was significantly associated with anti- E. canis / E . ewingii antibodies (odds ratio = 2.9, 95% confidence interval: 1.3–6.7, P = 0.010) compared to controls by both multivariable logistic regression and structural equation modelling. It was demonstrated that an increased risk for E. canis / E . ewingii seropositivity is present in dogs with ClinL compared to clinically healthy control dogs, despite similar ectoparasitic prevention use and lifestyle. Based on these findings it is suggested that dogs with ClinL should not only be tested for E. canis co-infection using PCR but also serologically for E. canis / E . ewingii .
Diagnostic Uncertainty and the Epidemiology of Feline Foamy Virus in Pumas (Puma concolor)
Publisher: Springer Science and Business Media LLC
Date: 31-01-2020
DOI: 10.1038/S41598-020-58350-7
Abstract: Feline foamy virus (FFV) is a contact-dependent retrovirus forming chronic, largely apathogenic, infections in domestic and wild felid populations worldwide. Given there is no current ‘gold standard’ diagnostic test for FFV, efforts to elucidate the ecology and epidemiology of the virus may be complicated by unknown sensitivity and specificity of diagnostic tests. Using Bayesian Latent Class Analysis, we estimated the sensitivity and specificity of the only two FFV diagnostic tests available—ELISA and qPCR—as well as the prevalence of FFV in a large cohort of pumas from Colorado. We evaluated the diagnostic agreement of ELISA and qPCR, and whether differences in their diagnostic accuracy impacted risk factor analyses for FFV infection. Our results suggest ELISA and qPCR did not have strong diagnostic agreement, despite FFV causing a persistent infection. While both tests had similar sensitivity, ELISA had higher specificity. ELISA, but not qPCR, identified age to be a significant risk factor, whereas neither qPCR nor ELISA identified sex to be a risk factor. This suggests FFV transmission in pumas may primarily be via non-antagonistic, social interactions between adult conspecifics. Our study highlights that combined use of qPCR and ELISA for FFV may enhance estimates of the true prevalence of FFV and epidemiological inferences.
Ecosystem engineering by digging mammals: Effects on soil fertility and condition in Tasmanian temperate woodland
Publisher: The Royal Society
Date: 2019
DOI: 10.1098/RSOS.180621
Abstract: Many small- and medium-sized mammals dig for their food. This activity potentially affects soil condition and fertility. Digging is well developed especially in Australian mammals, many of which have recently become rare or extinct. We measured the effects of digging by mammals on soil in a Tasmanian temperate dry sclerophyll forest with an intact mammal community. The density of diggings was 5812 ha −1 , affecting 11% of the forest floor. Diggings were created at a rate of around 3113 diggings ha −1 yr −1 , disturbing 6.5% of the forest floor and displacing 7.1 m 3 ha −1 of soil annually. Most diggings were made by eastern bettongs ( Bettongia gaimardi) and short-beaked echidnas ( Tachyglossus aculeatus ). Many (approx. 30%) fresh diggings consisted of re-excavations of old diggings. Novel diggings displaced 5 m 3 ha yr −1 of soil. Diggings acted as traps for organic matter and sites for the formation of new soil, which had higher fertility and moisture content and lower hardness than undisturbed topsoil. These effects on soil fertility and structure were strongest in habitats with dry and poor soil. Creation of fine-scaled heterogeneity by mammals, and amelioration of dry and infertile soil, is a valuable ecosystem service that could be restored by reintroduction of digging mammals to habitats from which they have declined or gone extinct.
Dermatophilus congolensisInfection in Platypus (Ornithorhynchus anatinus), Tasmania, Australia, 2015
Publisher: Wildlife Disease Association
Date: 10-2016
DOI: 10.7589/2016-02-030R
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