Wendy C Turner

• PhD
• Researcher at United States Geological Survey

Wildlife management in the United States of America (US) is primarily delegated to the individual states wherein state wildlife agencies manage wildlife populations to achieve multiple and sometimes conflicting objectives. White-tailed deer (Odocoileus virginianus) are an important species in the Midwestern US whose populations are primarily manage...

Anthropogenically driven environmental change has imposed substantial threats on biodiversity, including the emergence of infectious diseases that have resulted in declines of wildlife globally. In response to pathogen invasion, maintaining diversity within host populations across heterogenous environments is essential to facilitating species persi...

Background: Although the rate of emerging infectious diseases that originate in wildlife has been increasing globally in recent decades, there is currently a lack of epidemiological data from wild animals. Methodology: We used serology to determine prior exposure to foot-and-mouth disease virus (FMDV), Brucella spp., and Coxiella burnetii and used...

Environmental and climatic factors, as well as host demographics and behaviour, significantly influence the exposure of herbivorous mammalian hosts to pathogens such as Bacillus anthracis, the causative agent of anthrax. Until the early 1990s in Kruger National Park (KNP), kudu (Tragelaphus strepsiceros) was the host species most affected by anthra...

The diagnosis of anthrax, a zoonotic disease caused by Bacillus anthracis can be complicated by detection of closely related species. Conventional diagnosis of anthrax involves microscopy, culture identification of bacterial colonies and molecular detection. Genetic markers used are often virulence gene targets such as B. anthracis protective antig...

Chronic wasting disease (CWD) is a fatal prion disease of cervids that has spread across much of North America. Although gold standard CWD diagnostics involve postmortem testing of medial retropharyngeal lymph nodes or obex (brain stem), a key tissue sample for antemortem testing is rectoanal mucosa-associated lymphoid tissue (RAMALT). However, col...

The diagnosis of anthrax, a zoonotic disease caused by Bacillus anthracis can be complicated by detection of closely related species. Conventional diagnosis of anthrax involves microscopy, culture identification of bacterial colonies and molecular detection. Genetic markers used are often virulence gene targets such as Bacillus anthracis protective...

With emerging infectious disease outbreaks in human, domestic and wild animal populations on the rise, improvements in pathogen characterization and surveillance are paramount for the protection of human and animal health, as well as the conservation of ecologically and economically important wildlife. Genomics offers a range of suitable tools to m...

An important part of infectious disease management is predicting factors that influence disease outbreaks, such as R, the number of secondary infections arising from an infected individual. Estimating R is particularly challenging for environmentally transmitted pathogens given time lags between cases and subsequent infections. Here, we calculated...

Background The distribution of resources can affect animal range sizes, which in turn may alter infectious disease dynamics in heterogenous environments. The risk of pathogen exposure or the spatial extent of outbreaks may vary with host range size. This study examined the range sizes of herbivorous anthrax host species in two ecosystems and relati...

Disease monitoring in free-ranging wildlife is a challenge and often relies on passive surveillance. Alternatively, proactive surveillance that relies on the detection of specific antibodies could give more reliable and timely insight into disease presence and prevalence in a population, especially if the evidence of disease occurs below detection...

Disease monitoring in free-ranging wildlife is a challenge and often relies on passive surveillance. Alternatively, proactive surveillance that relies on the detection of specific antibodies could give more reliable and timely insight into disease presence and prevalence in a population, especially if it occurs below detection thresholds for passiv...

Anthrax is a lethal bacterial zoonosis primarily affecting herbivorous wildlife and livestock. Upon host death Bacillus anthracis vegetative cells form spores capable of surviving for years in soil. Anthrax transmission requires host exposure to large spore doses. Thus, conditions that facilitate higher spore concentrations or promote spore surviva...

Movement behavior is an important contributor to habitat selection and its incorporation in disease risk models has been somewhat neglected. The habitat preferences of host individuals affect their probability of exposure to pathogens. If preference behavior can be incorporated in ecological niche models (ENMs) when data on pathogen distributions a...

Proclaimed in 1907, Etosha National Park in northern Namibia is an iconic dryland system with a rich history of wildlife conservation and research. A recent research symposium on wildlife conservation in the Greater Etosha Landscape (GEL) highlighted increased concern of how intensification of global change will affect wildlife conservation based o...

Environmental factors are common forces driving infectious disease dynamics. We compared interannual and seasonal patterns of anthrax infections in two multihost systems in southern Africa: Etosha National Park, Namibia, and Kruger National Park, South Africa. Using several decades of mortality data from each system, we assessed possible transmissi...

Exposure and immunity to generalist pathogens differ among host species and vary across spatial scales. Anthrax, caused by a multi-host bacterial pathogen, Bacillus anthracis, is enzootic in Kruger National Park (KNP), South Africa and Etosha National Park (ENP), Namibia. These parks share many of the same potential host species, yet the main anthr...

Bacillus anthracis, the causative agent of anthrax disease, is a worldwide threat to livestock, wildlife and public health. While analyses of genetic data from across the globe have increased our understanding of this bacterium’s population genomic structure, the influence of selective pressures on this successful pathogen is not well understood. I...

Globally, anthrax outbreaks pose a serious threat to people, livestock, and wildlife. Furthermore, environmental change can exacerbate these outbreak dynamics by altering the host–pathogen relationship. However, little is known about how the quantitative spatial dynamics of host movement and environmental change may affect the spread of Bacillus an...

Disease outbreaks are a consequence of interactions among the three components of a host–parasite system: the infectious agent, the host and the environment. While virulence and transmission are widely investigated, most studies of parasite life-history trade-offs are conducted with theoretical models or tractable experimental systems where transmi...

When a transmission hotspot for an environmentally persistent pathogen establishes in otherwise high-quality habitat, the disease may exert a strong impact on a host population. However, fluctuating environmental conditions lead to heterogeneity in habitat quality and animal habitat preference, which may interrupt the overlap between selected and r...

Here we present a developing probabilistic simulation model and tool to assess likely lead times from emergence to detection and arrival for new emerging infectious diseases (EIDs). Key aspects include combining real-world data available on multiple scales with a flexible underlying disease model. As demonstrated by the SARS-CoV-2 pandemic and othe...

The persistence of a parasite species in an ecological community is determined both by its environmental tolerance and host breadth. The relative contribution of these niche characteristics to parasite community structure is challenging to parse because host persistence is also a consequence of extrinsic environmental factors. We investigated haemo...

The relationship between parasite virulence and transmission is a pillar of evolutionary theory that has implications for public health. Part of this canon involves the idea that virulence and free-living survival (a key component of transmission) may have different relationships in different host-parasite systems. Most examinations of the evolutio...

The latitudinal diversity gradient (LDG) is an established macroecological pattern, but is poorly studied in microbial organisms, particularly parasites. In this study, we tested whether latitude, elevation, and host species predicted patterns of prevalence, alpha diversity, and community turnover of hemosporidian parasites. We expected parasite di...

The relationship between parasite virulence and transmission is a pillar of evolutionary theory that has specific implications for public health. Part of this canon involves the idea that virulence and free-living survival (a key component of transmission) may have different relationships in different host-parasite systems. Most examinations of the...

The Latitudinal Diversity Gradient (LDG) is an established macroecological pattern, but is poorly studied in microbial organisms, particularly parasites. In this study, we tested whether latitude, elevation and host species predicted patterns of prevalence, alpha diversity and community turnover of haemosporidian parasites. We expected parasite div...

Bacillus anthracis, the etiological agent of anthrax, is a well-established model organism. For B. anthracis and most other infectious diseases, knowledge regarding transmission and infection parameters in natural systems, in large part, comprises data gathered from closely controlled laboratory experiments. Fatal, natural anthrax infections transm...

Bacillus anthracis, the causative agent of anthrax, is a considerable global health threat affecting wildlife, livestock, and the general public. In this study whole-genome sequence analysis of over 350 B. anthracis isolates was used to establish a new high-resolution global genotyping framework that is both biogeographically informative, and compa...

Bacillus anthracis, the causative agent of anthrax, is a considerable global health threat affecting wildlife, livestock, and the general public. In this study whole-genome sequence analysis of over 350 B. anthracis isolates was used to establish a new high-resolution global genotyping framework that is both biogeographically informative, and compa...

The outbreak and transmission of disease-causing pathogens are contributing to the unprecedented rate of biodiversity decline. Recent advances in genomics have coalesced into powerful tools to monitor, detect, and reconstruct the role of pathogens impacting wildlife populations. Wildlife researchers are thus uniquely positioned to merge ecological...

The outbreak and transmission of disease-causing pathogens are contributing to the unprecedented rate of biodiversity decline. Recent advances in genomics have coalesced into powerful tools to monitor, detect, and reconstruct the role of pathogens impacting wildlife populations. Wildlife researchers are thus uniquely positioned to merge ecological...

How a disease is transmitted affects our ability to determine R0, the average number of new cases caused by an infectious host at the onset of an epidemic. R0 becomes progressively more difficult to compute as transmission varies from directly transmitted diseases to diseases that are vector-borne to environmentally transmitted diseases. Pathogens...

The outbreak and transmission of disease-causing pathogens are contributing to the unprecedented rate of biodiversity decline. Recent advances in genomics have coalesced into powerful tools to monitor, detect, and reconstruct the role of pathogens impacting wildlife populations. Wildlife researchers are thus uniquely positioned to merge ecological...

Bloomsbury Education and Childhood Studies

Environmentally transmitted diseases are comparatively poorly understood and managed, and their ecology is particularly understudied. Here we identify challenges of studying environmental transmission and persistence with a six-sided interdisciplinary review of the biology of anthrax (Bacillus anthracis). Anthrax is a zoonosis that is capable of ma...

Anthrax in herbivorous wildlife and livestock is generally assumed to be transmitted via ingestion or inhalation of Bacillus anthracis spores. Although recent studies have highlighted the importance of the ingestion route for anthrax transmission, little is known about the inhalational route in natural systems. Dust bathing could aerosolize soilbor...

Background: Anthrax is a globally distributed disease affecting primarily herbivorous mammals. It is caused by the soil-dwelling and spore-forming bacterium Bacillus anthracis. The dormant B. anthracis spores become vegetative after ingestion by grazing mammals. After killing the host, B. anthracis cells return to the soil where they sporulate, com...

Spatial localization of an obligate-killing, free-living pathogen generates a landscape of patches where new infections occur. As an infectious patch ages, both pathogen exposure at the patch and the probability of lethal infection following exposure can decline. We model stage-structured infectious patches, where non-lethal exposure can naturally...

Environmentally transmitted diseases are comparatively poorly understood and managed, and their ecology is particularly understudied. Here we identify challenges of studying environmental transmission and persistence with a six‐sided interdisciplinary review of the biology of anthrax (Bacillus anthracis). Anthrax is a zoonotic disease capable of ma...

Bacillus anthracis strains K1 and K2 were isolated from two plains zebra anthrax carcasses in Etosha National Park, Namibia. These are draft genomes obtained by Illumina MiSeq sequencing of isolates collected from culture of blood-soaked soil from each carcass.

We document morphological descriptions for 3 newly described Eimeria spp. that infect springbok (Antidorcas marsupialis). Eimeria antidorcasi n. sp. oocysts are ovoid, with average size (n = 346) 26.2 x 18.8 (19.2-33.5 x 13.1-26.5) mu m, a length/width ratio of 1.4 (1.2-2.0), a micropyle, and a polar granule sometimes present. Sporocysts are ovoid...

To mitigate the effects of zoonotic diseases on human and animal populations, it is critical to understand what factors alter transmission dynamics. Here we assess the risk of exposure to lethal concentrations of the anthrax bacterium, Bacillus anthracis, for grazing animals in a natural system over time through different transmission mechanisms. W...

Sex hormones, reproductive status, and pathogen load all affect stress. Together with stress, these factors can modulate the immune system and affect disease incidence. Thus, it is important to concurrently measure these factors, along with their seasonal fluctuations, to better understand their complex interactions. Using steroid hormone metabolit...

Parasites can shape the foraging behaviour of their hosts through cues indicating risk of infection. When cues for risk co-occur with desired traits such as forage quality, individuals face a trade-off between nutrient acquisition and parasite exposure. We evaluated how this trade-off may influence disease transmission in a 3-year experimental stud...

Background Most vertebrates experience coinfections, and many pathogen-pathogen interactions occur indirectly through the host immune system. These interactions are particularly strong in mixed micro-macroparasite infections because of immunomodulatory effects of helminth parasites. While these trade-offs have been examined extensively in laborator...

Sex hormones, reproductive status, and pathogen load all affect stress. Together with stress, these factors can modulate the immune system and affect disease incidence. Thus, it is important to concurrently measure these factors, along with their seasonal fluctuations, to better understand their complex interactions. Using steroid hormone metabolit...

Environmental reservoirs are essential in the maintenance and transmission of anthrax but are poorly characterized. The anthrax agent, Bacillus anthracis was long considered an obligate pathogen that is dormant and passively transmitted in the environment. However, a growing number of laboratory studies indicate that, like some of its close relativ...

Pathogen evasion of the host immune system is a key force driving extreme polymorphism in genes of the major histocompatibility complex (MHC). Although this gene family is well characterized in structure and function, there is still much debate surrounding the mechanisms by which MHC diversity is selectively maintained. Many studies have investigat...

Pathogens transmitted via the environment are often aggregated in space, and seasonal variation in wildlife foraging behaviour may alter contact rates with environmental pathogens. The soil-borne bacterium Bacillus anthracis Cohn, 1872 causes anthrax, and herbivores acquire gastrointestinal anthrax by ingesting spores. Therefore host foraging behav...

Few studies have examined host‐pathogen interactions in wildlife from an immunological perspective, particularly in the context of seasonal and longitudinal dynamics. In addition, though most ecological immunology studies employ serological antibody assays, endpoint titre determination is usually based on subjective criteria and needs to be made mo...

Background Advances in GPS technology have created both opportunities in ecology as well as a need for analytical tools that can deal with the growing volume of data and ancillary variables associated with each location. Results We present T-LoCoH, a home range construction algorithm that incorporates time into the construction and aggregation of...

Anthrax, caused by the bacterium Bacillus anthracis, is a seasonally occurring infectious disease affecting primarily herbivorous wildlife and livestock. The seasonality of anthrax outbreaks varies among locations, making it difficult to develop a single consistent ecological description of this disease. Over 44 years of mortality surveillance, mos...

Clusteranalysis of 31-marker MLVA data on 377 Namibian isolates. An isolate of the B-branch (Malilangwe 2005) was added as an outgroup. To protect the privacy and security of farm owners, the identities of farms are designated simply by upper case letters. (TIF)

Median probabilities and 95% credible intervals for genotypes sampled from the Etosha National Park. GTs occurring ≤5 times are pooled into the “Other” category. Numbers are given for years 2005–2010 when most of the samples were collected. Years 1983, 1987 and 1988–2002, including sampling gaps in 1990, 1993, 1996–99 and 2001, are pooled into the...

Cluster analysis of SNR data from all isolates of GT18. To protect the privacy and security of farm owners, the identities of farms are designated simply by upper case letters. (TIF)

Records on ENP isolates used for outbreak analysis. (PDF)

Cluster analysis of SNR data from all isolates of GT9. To protect the privacy and security of farm owners, the identities of farms are designated simply by upper case letters. (TIF)

Observed fragment lengths and code numbers used in the 31-marker MLVA. Fragment lengths observed on an ABI 310 capillary electrophoresis are compared with expected fragment lengths. The latter are taken from the values of alleles provided by Lista et al. [9] and deduced from sequences of B. anthracis available at Genbank. Values of unpublished alle...

Diversity indices and allele numbers of MLVA markers with respect to the collection investigated. (XLS)

Distribution of genetic distances by host species similarity. (TIF)

SNP groups and code values for the 31 markers used in MLVA. Code numbers are identical with copy numbers of the repeat sequences where possible. For the purpose of orientation the appropriate copy code numbers are added for the Ames ancestor strain as deduced from the sequence available on GenBank, accession No.: AE017334.2 GI:50082967 (XLS)

Cluster analysis of SNR data from all isolates of GT22. To protect the privacy and security of farm owners, the identities of farms are designated simply by upper case letters. (TIF)

The recent development of genetic markers for Bacillus anthracis has made it possible to monitor the spread and distribution of this pathogen during and between anthrax outbreaks. In Namibia, anthrax outbreaks occur annually in the Etosha National Park (ENP) and on private game and livestock farms. We genotyped 384 B. anthracis isolates collected b...

1. Seasonality of rainfall can exert a strong influence on animal condition and on host–parasite interactions. The body condition of ruminants fluctuates seasonally in response to changes in energy requirements, foraging patterns and resource availability, and seasonal variation in parasite infections may further alter ruminant body condition. 2. T...

Wild African elephants (Loxodonta africana) are commonly infected with intestinal strongyle parasites. Our objective was to determine baseline fecal strongyle egg counts for elephants in the northeast region of Etosha National Park, Namibia and determine if these numbers were affected by annual rainfall, elephant demography (age of individuals and...

Wild African elephants (Loxodonta africana) are commonly infected with intestinal strongyle parasites. Our objective was to determine baseline fecal strongyle egg counts for elephants in the northeast region of Etosha National Park, Namibia and determine if these numbers were affected by annual rainfall, elephant demography (age of individuals and...

Host-parasite dynamics can be strongly affected by seasonality and age-related host immune responses. We investigated how observed variation in the prevalence and intensity of parasite egg or oocyst shedding in four co-occurring ungulate species may reflect underlying seasonal variation in transmission and host immunity. This study was conducted Ju...

Estimates of parasite intensity within host populations are essential for many studies of host-parasite relationships. Here we evaluated the seasonal, age- and sex-related variability in faecal water content for two wild ungulate species, springbok (Antidorcas marsupialis) and plains zebra (Equus quagga). We then assessed whether or not faecal wate...

Epidemiological studies typically focus on single-parasite systems, although most hosts harbor multiple parasite species; thus, the potential impacts of co-infection on disease dynamics are only beginning to be recognized. Interactions between macroparasites, such as gastrointestinal nematodes, and microparasites causing diseases like TB, AIDS, and...