Fatal attraction: vegetation responses to nutrient inputs attract herbivores to infectious anthrax carcass sites

Turner, Wendy C.; Kausrud, Kyrre; Krishnappa, Yathin S.; Cromsigt, Joris P. G. M.; Ganz, Holly H.; Mapaure, Isaac; Cloete, Claudine C.; Havarua, Zepee; Küsters, Martina; Getz, Wayne M.; Stenseth, Nils Chr.

doi:10.1098/rspb.2014.1785

Cited by 95 publications

(179 citation statements)

References 39 publications

(50 reference statements)

Supporting

Mentioning

170

Contrasting

Unclassified

Order By: Relevance

“…Grass sampling follows the methods of Turner et al 11,. and data collected in 2012–2013 from that study are combined with new data collected in 2014 to build the grazing exposure models.…”

Section: Methodsmentioning

confidence: 99%

“…The concentration of BA in soils and grasses was assessed via bacterial culture adapted from standard soil protocols101138. Five grams of homogenized soil was combined with 45 ml 0.1% sodium pyrophosphate in a sterile 50 ml centrifuge tube.…”

Section: Methodsmentioning

confidence: 99%

“…BA enters the environment from carcasses and, accordingly, carcass sites are considered likely foci for pathogen ingestion and disease transmission11. However, long-lived BA spores can be transported away from carcass sites by several biotic (e.g., vertebrate or invertebrate scavengers) or abiotic (e.g., water or wind) processes1213141516.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Lethal exposure: An integrated approach to pathogen transmission via environmental reservoirs

Turner

Kausrud

Beyer

et al. 2016

Sci Rep

Self Cite

View full text Add to dashboard Cite

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. We follow pathogen concentrations at anthrax carcass sites and waterholes for five years and estimate infection risk as a function of grass, soil or water intake, age of carcass sites, and the exposure required for a lethal infection. Grazing, not drinking, seems the dominant transmission route, and transmission is more probable from grazing at carcass sites 1-2 years of age. Unlike most studies of virulent pathogens that are conducted under controlled conditions for extrapolation to real situations, we evaluate exposure risk under field conditions to estimate the probability of a lethal dose, showing that not all reservoirs with detectable pathogens are significant transmission pathways.Understanding the ecological processes that drive zoonotic disease outbreaks is important in mitigating their effects on human and animal populations. One critical factor affecting infectious disease dynamics is spatio-temporal heterogeneity in transmission 1,2 . For directly transmitted pathogens, this heterogeneity can be described through peer to peer contact rates and the structure of social networks in host populations [3][4][5] . When pathogens are acquired from environmental reservoirs, the pathogen's distribution in the environment and the interaction between host behavior and reservoir becomes the crucial link in transmission. Despite the global burden of diseases with environmental reservoirs (like cholera, tularemia, polio, botulism, anthrax, bubonic plague, leptospirosis, enteropathogenic E. coli and others 6 ), microbial ecology in the field is currently understudied due to the difficulties of monitoring microbes in their natural environment. Though progress is being made in risk assessment studies, more data are needed on diseases currently posing threats to public health, livestock health, and wildlife health. Moreover, to calibrate the risk and thus an appropriate response to emerging diseases following environmental change or the release of bioweapons, we need to know their long-term behavior in natural systems.The distribution of infectious agents in the environment is typically aggregated due to pulsed releases from infected hosts, creating heterogeneity in the risk of exposure for future hosts. Public health scientists assess risk of infection by identifying disease agents, quantifying exposure, and characterizing dose-response relationships 7,8 .

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Lethal exposure: An integrated approach to pathogen transmission via environmental reservoirs

Turner

Kausrud

Beyer

et al. 2016

Sci Rep

Self Cite

View full text Add to dashboard Cite

show abstract

“…More recently, serological evidence confirms exposure may be frequent in wildlife populations with individuals surviving sub-lethal infections (Bagamian et al 2013). Exposure is most likely through ingestion during grazing or foraging (Turner et al 2013), including grazing at carcass sites of previous anthrax deaths (Turner et al 2014) with localized secondary cases from (short-term) mechanical transmission from necrophagous or hematophagous flies on certain landscapes (Blackburn et al 2014b; Blackburn et al 2014c). …”

Section: Introductionmentioning

confidence: 99%

Predicting Disease Risk, Identifying Stakeholders, and Informing Control Strategies: A Case Study of Anthrax in Montana

Morris

Blackburn

2016

EcoHealth

View full text Add to dashboard Cite

Infectious diseases that affect wildlife and livestock are challenging to manage, and can lead to large scale die offs, economic losses, and threats to human health. The management of infectious diseases in wildlife and livestock is made easier with knowledge of disease risk across space and identifying stakeholders associated with high risk landscapes. This study focuses on anthrax, caused by the bacterium Bacillus anthracis, risk to wildlife and livestock in Montana. There is a history of anthrax in Montana, but the spatial extent of disease risk and subsequent wildlife species at risk are not known. Our objective was to predict the potential geographic distribution of anthrax risk across Montana, identify wildlife species at risk and their distributions, and define stakeholders. We used an ecological niche model to predict the potential distribution of anthrax risk. We overlaid susceptible wildlife species distributions and land ownership delineations on our risk map. We found that there was an extensive region across Montana predicted as potential anthrax risk. These potentially risky landscapes overlapped the ranges of all 6 ungulate species considered in the analysis and livestock grazing allotments, and this overlap was on public and private land for all species. Our findings suggest that there is the potential for a multi species anthrax outbreak on multiple landscapes across Montana. Our potential anthrax risk map can be used to prioritize landscapes for surveillance and for implementing livestock vaccination programs.

show abstract

“…There are a few studies conducted so far on physicochemical properties of soils in North-central Namibia (Turner et al, 2014;Hillyer et al, 2006). However, wide area studies on soil fertility, salinity and sodicity in seasonal wetlands, such as oshanas, are still limited.…”

Section: Introductionmentioning

confidence: 99%

Characteristics of soils under seasonally flooded wetlands (oshanas) in north-central Namibia

Watanabe¹,

Itanna²,

Fujioka³

et al. 2016

Afr. J. Agric. Res.

View full text Add to dashboard Cite

Lowland wetlands generally have a high agricultural production potential and can be local hot-spots for biodiversity. Specific seasonal wetland system is largely distributed in north-central Namibia. Seasonal wetlands consist of seasonal river wetlands (locally known as oshanas). However, studies on soil fertility, salinity and sodicity in seasonal river wetlands are still limited in this area. The objective of this study was hence to investigate the soil fertility status of seasonal wetlands and evaluate their potential for agricultural production and consider sustainability of the land use system. Soil samples were collected from 102 different spots of the flood plain within 3 major seasonal rivers, and analyzed for their physico-chemical properties and salinity and sodicity. The findings for average soil organic carbon (1.94 g kg -1 ) and average clay contents (102.3 g kg -1 ) of seasonal rivers were drastically lower than the wetland of semi-arid Africa regions (organic carbon, 5.8 g kg -1 ; clay contents, 340 g kg -1 ), and organic carbon and clay content significantly (p<0.05) decreased at the lower part of each seasonal river. Most of the seasonal river soil's' electrical conductivity of saturated paste extract (ECe) and the sodium adsorption ratio of the saturated paste extract (SAR) were more than 4 dS m -1 and 13, respectively. However, there were large differences in electrical conductivity of saturated paste extract (ECe) and the sodium adsorption ratio of the saturated paste extract (SAR) values among the sampling spots. These findings suggest the high agricultural importance to improve the soil organic matter and clay contents, and land selection to avoid the strongly high saline-sodic soil sites in seasonal river.

show abstract

Fatal attraction: vegetation responses to nutrient inputs attract herbivores to infectious anthrax carcass sites

Cited by 95 publications

References 39 publications

Lethal exposure: An integrated approach to pathogen transmission via environmental reservoirs

Lethal exposure: An integrated approach to pathogen transmission via environmental reservoirs

Predicting Disease Risk, Identifying Stakeholders, and Informing Control Strategies: A Case Study of Anthrax in Montana

Characteristics of soils under seasonally flooded wetlands (oshanas) in north-central Namibia

Contact Info

Product

Resources

About