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Zidon R, Garti S, Getz WM, Saltz D. Zebra migration strategies and anthrax in Etosha National Park, Namibia. Ecosphere 2017; 8. [PMID: 29276646 DOI: 10.1002/ecs2.1925] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Partial seasonal migration is ubiquitous in many species. We documented this phenomenon in plains zebra (Equus burchelli) in Etosha National Park, Namibia (ENP), and provided a cost-benefit analysis as it relates to the spatial distribution of water, vegetation and endemic anthrax. This analysis draws upon two years of ENP zebra movement data that reveal two sub-populations: migrators and non-migrators. Migrators are shown to be behaviorally dominant in the way they utilize space and use water holes. We raise the possibility that the co-existence of these two groups reflects an evolutionary process, and the size of each group maintains evolutionary equilibrium.
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Affiliation(s)
- Royi Zidon
- The Mitrani Department of Desert Ecology, Swiss Institute for Dryland Energy and Environmental Research, Blaustein Institutes for Desert Research, Ben-Gurion University, Israel.,Department of Environmental Science Policy & Management, University of California, Berkeley, California, USA
| | - Shimon Garti
- Institute of Mathematics, Hebrew University of Jerusalem, Israel and Department of Ecology, Evolution and Behavior, Hebrew University of Jerusalem, Israel
| | - Wayne M Getz
- Department of Environmental Science Policy & Management, University of California, Berkeley, California, USA.,School of Mathematical Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - David Saltz
- The Mitrani Department of Desert Ecology, Swiss Institute for Dryland Energy and Environmental Research, Blaustein Institutes for Desert Research, Ben-Gurion University, Israel
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Abstract
To survive adverse conditions, some bacterial species are capable of developing into a cell type, the "spore," which exhibits minimal metabolic activity and remains viable in the presence of multiple environmental challenges. For some pathogenic bacteria, this developmental state serves as a means of survival during transmission from one host to another. Spores are the highly infectious form of these bacteria. Upon entrance into a host, specific signals facilitate germination into metabolically active replicating organisms, resulting in disease pathogenesis. In this article, we will review spore structure and function in well-studied pathogens of two genera, Bacillus and Clostridium, focusing on Bacillus anthracis and Clostridium difficile, and explore current data regarding the lifestyles of these bacteria outside the host and transmission from one host to another.
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53
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Mangesho PE, Neselle MO, Karimuribo ED, Mlangwa JE, Queenan K, Mboera LEG, Rushton J, Kock R, Häsler B, Kiwara A, Rweyemamu M. Exploring local knowledge and perceptions on zoonoses among pastoralists in northern and eastern Tanzania. PLoS Negl Trop Dis 2017; 11:e0005345. [PMID: 28146556 PMCID: PMC5325590 DOI: 10.1371/journal.pntd.0005345] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Revised: 02/24/2017] [Accepted: 01/22/2017] [Indexed: 11/29/2022] Open
Abstract
Background Zoonoses account for the most commonly reported emerging and re-emerging infectious diseases in Sub-Saharan Africa. However, there is limited knowledge on how pastoral communities perceive zoonoses in relation to their livelihoods, culture and their wider ecology. This study was carried out to explore local knowledge and perceptions on zoonoses among pastoralists in Tanzania. Methodology and principal findings This study involved pastoralists in Ngorongoro district in northern Tanzania and Kibaha and Bagamoyo districts in eastern Tanzania. Qualitative methods of focus group discussions, participatory epidemiology and interviews were used. A total of 223 people were involved in the study. Among the pastoralists, there was no specific term in their local language that describes zoonosis. Pastoralists from northern Tanzania possessed a higher understanding on the existence of a number of zoonoses than their eastern districts' counterparts. Understanding of zoonoses could be categorized into two broad groups: a local syndromic framework, whereby specific symptoms of a particular illness in humans concurred with symptoms in animals, and the biomedical framework, where a case definition is supported by diagnostic tests. Some pastoralists understand the possibility of some infections that could cross over to humans from animals but harm from these are generally tolerated and are not considered as threats. A number of social and cultural practices aimed at maintaining specific cultural functions including social cohesion and rites of passage involve animal products, which present zoonotic risk. Conclusions These findings show how zoonoses are locally understood, and how epidemiology and biomedicine are shaping pastoralists perceptions to zoonoses. Evidence is needed to understand better the true burden and impact of zoonoses in these communities. More studies are needed that seek to clarify the common understanding of zoonoses that could be used to guide effective and locally relevant interventions. Such studies should consider in their approaches the pastoralists’ wider social, cultural and economic set up. Zoonoses are diseases transmissible between animals and humans. Risk factors include animal slaughter, the handling and preparing food of animal origin and particularly the consumption of such food when raw or undercooked. Pastoralists are daily in contact with their livestock and are likely to be more frequently exposed to zoonotic pathogens. However, very few studies have focused on the understanding of zoonoses and related risk factors among pastoralists of Tanzania. This was striking considering pastoralists’ close bond with and reliance on livestock for their nutritional needs and livelihoods. Our study was implemented in pastoral communities located in two different ecological zones of Tanzania. In all ten communities visited no local term for zoonoses existed, yet participants recognised there are some symptoms that appear in both animals and humans. However, these were not thought to be harmful to humans and people did not perceive the animal products from which they originate to be dangerous. Other zoonoses were known because community members received a diagnosis from a health facility. We also learnt that cultural practices relating to the preparation and consumption of food of animal origin were considered more important to the community than the risk of infection. The findings of this study highlight the gaps in knowledge of zoonoses among pastoralists in Tanzania and the importance of social and cultural practices. Therefore, we propose that interventions to control zoonoses should be informed by research of peoples’ behaviours related to handling of animals and consumption of animal source foods.
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Affiliation(s)
- Peter Ernest Mangesho
- Department of Veterinary Medicine and Public Health, Sokoine University of Agriculture, Morogoro, Tanzania
- Southern African Centre for Infectious Disease Surveillance, Sokoine University of Agriculture, Morogoro, Tanzania
- Department of Health Systems and Policy Research, National Institute for Medical Research, Amani Research Center, Muheza, Tanzania
- * E-mail:
| | - Moses Ole Neselle
- Southern African Centre for Infectious Disease Surveillance, Sokoine University of Agriculture, Morogoro, Tanzania
| | - Esron D. Karimuribo
- Department of Veterinary Medicine and Public Health, Sokoine University of Agriculture, Morogoro, Tanzania
- Southern African Centre for Infectious Disease Surveillance, Sokoine University of Agriculture, Morogoro, Tanzania
| | - James E. Mlangwa
- Department of Veterinary Medicine and Public Health, Sokoine University of Agriculture, Morogoro, Tanzania
| | - Kevin Queenan
- Department of Pathobiology and Population Sciences, Royal Veterinary College, University of London, London, United Kingdom
| | - Leonard E. G. Mboera
- Directorate of Information Technologies and Communication, National Institute for Medical Research, Dar es Salaam, Tanzania
| | - Jonathan Rushton
- Directorate of Information Technologies and Communication, National Institute for Medical Research, Dar es Salaam, Tanzania
| | - Richard Kock
- Directorate of Information Technologies and Communication, National Institute for Medical Research, Dar es Salaam, Tanzania
| | - Barbara Häsler
- Directorate of Information Technologies and Communication, National Institute for Medical Research, Dar es Salaam, Tanzania
| | - Angwara Kiwara
- Department of Development Studies, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Mark Rweyemamu
- Department of Veterinary Medicine and Public Health, Sokoine University of Agriculture, Morogoro, Tanzania
- Southern African Centre for Infectious Disease Surveillance, Sokoine University of Agriculture, Morogoro, Tanzania
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54
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Ladbury G, Allan KJ, Cleaveland S, Davis A, de Glanville WA, Forde TL, Halliday JEB, Haydon DT, Kibiki G, Kiwelu I, Lembo T, Maro V, Mmbaga BT, Ndyetabura T, Sharp J, Thomas K, Zadoks RN. One Health Research in Northern Tanzania - Challenges and Progress. East Afr Health Res J 2017; 1:8-18. [PMID: 34308154 PMCID: PMC8279194 DOI: 10.24248/eahrj-d-16-00379] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Accepted: 02/02/2017] [Indexed: 11/20/2022] Open
Abstract
East Africa has one of the world's fastest growing human populations-many of whom are dependent on livestock-as well as some of the world's largest wildlife populations. Humans, livestock, and wildlife often interact closely, intimately linking human, animal, and environmental health. The concept of One Health captures this interconnectedness, including the social structures and beliefs driving interactions between species and their environments. East African policymakers and researchers are recognising and encouraging One Health research, with both groups increasingly playing a leading role in this subject area. One Health research requires interaction between scientists from different disciplines, such as the biological and social sciences and human and veterinary medicine. Different disciplines draw on norms, methodologies, and terminologies that have evolved within their respective institutions and that may be distinct from or in conflict with one another. These differences impact interdisciplinary research, both around theoretical and methodological approaches and during project operationalisation. We present experiential knowledge gained from numerous ongoing projects in northern Tanzania, including those dealing with bacterial zoonoses associated with febrile illness, foodborne disease, and anthrax. We use the examples to illustrate differences between and within social and biological sciences and between industrialised and traditional societies, for example, with regard to consenting procedures or the ethical treatment of animals. We describe challenges encountered in ethical approval processes, consenting procedures, and field and laboratory logistics and offer suggestions for improvement. While considerable investment of time in sensitisation, communication, and collaboration is needed to overcome interdisciplinary challenges inherent in One Health research, this can yield great rewards in paving the way for successful implementation of One Health projects. Furthermore, continued investment in African institutions and scientists will strengthen the role of East Africa as a world leader in One Health research.
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Affiliation(s)
- Georgia Ladbury
- Institute of Biodiversity Animal Health and Comparative Medicine, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Kathryn J Allan
- Institute of Biodiversity Animal Health and Comparative Medicine, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Sarah Cleaveland
- Institute of Biodiversity Animal Health and Comparative Medicine, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Alicia Davis
- School of Geographical and Earth Sciences, College of Science and Engineering, University of Glasgow, Glasgow, UK
| | - William A de Glanville
- Institute of Biodiversity Animal Health and Comparative Medicine, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Taya L Forde
- Institute of Biodiversity Animal Health and Comparative Medicine, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Jo E B Halliday
- Institute of Biodiversity Animal Health and Comparative Medicine, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Daniel T Haydon
- Institute of Biodiversity Animal Health and Comparative Medicine, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Gibson Kibiki
- Kilimanjaro Clinical Research Institute, Good Samaritan Foundation, Moshi, Tanzania.,East African Health Research Commission, Arusha, Tanzania
| | - Ireen Kiwelu
- Kilimanjaro Clinical Research Institute, Good Samaritan Foundation, Moshi, Tanzania
| | - Tiziana Lembo
- Institute of Biodiversity Animal Health and Comparative Medicine, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Venance Maro
- Kilimanjaro Christian Medical Centre, Good Samaritan Foundation, Moshi, Tanzania
| | - Blandina T Mmbaga
- Kilimanjaro Clinical Research Institute, Good Samaritan Foundation, Moshi, Tanzania.,Kilimanjaro Christian Medical Centre, Good Samaritan Foundation, Moshi, Tanzania
| | - Theonest Ndyetabura
- Kilimanjaro Clinical Research Institute, Good Samaritan Foundation, Moshi, Tanzania
| | - Jo Sharp
- School of Geographical and Earth Sciences, College of Science and Engineering, University of Glasgow, Glasgow, UK
| | - Kate Thomas
- Kilimanjaro Clinical Research Institute, Good Samaritan Foundation, Moshi, Tanzania.,Centre for International Health, University of Otago, Dunedin, New Zealand
| | - Ruth N Zadoks
- Kilimanjaro Clinical Research Institute, Good Samaritan Foundation, Moshi, Tanzania
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Gilbertson MLJ, Carver S, VandeWoude S, Crooks KR, Lappin MR, Craft ME. Is pathogen exposure spatially autocorrelated? Patterns of pathogens in puma (Puma concolor) and bobcat (Lynx rufus). Ecosphere 2016. [DOI: 10.1002/ecs2.1558] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Affiliation(s)
- Marie L. J. Gilbertson
- Department of Veterinary Population MedicineUniversity of Minnesota Minneapolis Minnesota 55455 USA
| | - Scott Carver
- School of Biological SciencesUniversity of Tasmania Hobart Tasmania 7001 Australia
| | - Sue VandeWoude
- Department of Microbiology, Immunology and PathologyColorado State University Fort Collins Colorado 80523 USA
| | - Kevin R. Crooks
- Department of Fish, Wildlife and Conservation BiologyColorado State University Fort Collins Colorado 80523 USA
| | - Michael R. Lappin
- Department of Clinical SciencesColorado State University Fort Collins Colorado 80523 USA
| | - Meggan E. Craft
- Department of Veterinary Population MedicineUniversity of Minnesota Minneapolis Minnesota 55455 USA
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Nsoh AE, Kenu E, Forson EK, Afari E, Sackey S, Nyarko KM, Yebuah N. Mapping as a tool for predicting the risk of anthrax outbreaks in Northern Region of Ghana. Pan Afr Med J 2016; 25:14. [PMID: 28149439 PMCID: PMC5257015 DOI: 10.11604/pamj.supp.2016.25.1.6205] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Accepted: 12/05/2015] [Indexed: 12/03/2022] Open
Abstract
Introduction Anthrax is a febrile soil-born infectious disease that can affect all warm-blooded animals including man. Outbreaks of anthrax have been reported in northern region of Ghana but no concerted effort has been made to implement risk-based surveillance systems to document outbreaks so as to implement policies to address the disease. We generated predictive maps using soil pH, temperature and rainfall as predictor variables to identify hotspot areas for the outbreaks. Methods A 10-year secondary data records on soil pH, temperature and rainfall were used to create climate-based risk maps using ArcGIS 10.2. The monthly mean values of rainfall and temperature for ten years were calculated and anthrax related evidence based constant raster values were created as weights for the three factors. All maps were generated using the Kriging interpolation method. Results There were 43 confirmed outbreaks. The deaths involved were 131 cattle, 44 sheep, 15 goats, 562 pigs with 6 human deaths and 22 developed cutaneous anthrax. We found three strata of well delineated distribution pattern indicating levels of risk due to suitability of area for anthrax spore survival. The likelihood of outbreaks occurrence and reoccurrence was higher in Strata I, Strata II and strata III respectively in descending order, due to the suitability of soil pH, temperature and rainfall for the survival and dispersal of B. anthracis spore. Conclusion The eastern corridor of Northern region is a Hots spot area. Policy makers can develop risk based surveillance system and focus on this area to mitigate anthrax outbreaks and reoccurrence.
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Affiliation(s)
- Ayamdooh Evans Nsoh
- Veterinary Services Directorate Tamale, P.O. Box 241, Tamale, Northern Region, Ghana; Ghana Field Epidemiology and Laboratory Training Programme, Tamale, Northern Region, Ghana
| | - Ernest Kenu
- University of Ghana, College of Health Sciences, School of Public Health, Accra, Ghana
| | - Eric Kofi Forson
- Rudan Engineering Limited, 156 Atomic-Haatso Road, P.O. Box CT 828, Cantonments, Accra, Ghana
| | - Edwin Afari
- Ghana Field Epidemiology and Laboratory Training Programme, Tamale, Northern Region, Ghana
| | - Samuel Sackey
- Ghana Field Epidemiology and Laboratory Training Programme, Tamale, Northern Region, Ghana
| | - Kofi Mensah Nyarko
- Ghana Field Epidemiology and Laboratory Training Programme, Tamale, Northern Region, Ghana
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57
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Bacillus cereus Biovar Anthracis Causing Anthrax in Sub-Saharan Africa-Chromosomal Monophyly and Broad Geographic Distribution. PLoS Negl Trop Dis 2016; 10:e0004923. [PMID: 27607836 PMCID: PMC5015827 DOI: 10.1371/journal.pntd.0004923] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 07/23/2016] [Indexed: 11/19/2022] Open
Abstract
Through full genome analyses of four atypical Bacillus cereus isolates, designated B. cereus biovar anthracis, we describe a distinct clade within the B. cereus group that presents with anthrax-like disease, carrying virulence plasmids similar to those of classic Bacillus anthracis. We have isolated members of this clade from different mammals (wild chimpanzees, gorillas, an elephant and goats) in West and Central Africa (Côte d'Ivoire, Cameroon, Central African Republic and Democratic Republic of Congo). The isolates shared several phenotypic features of both B. anthracis and B. cereus, but differed amongst each other in motility and their resistance or sensitivity to penicillin. They all possessed the same mutation in the regulator gene plcR, different from the one found in B. anthracis, and in addition, carry genes which enable them to produce a second capsule composed of hyaluronic acid. Our findings show the existence of a discrete clade of the B. cereus group capable of causing anthrax-like disease, found in areas of high biodiversity, which are possibly also the origin of the worldwide distributed B. anthracis. Establishing the impact of these pathogenic bacteria on threatened wildlife species will require systematic investigation. Furthermore, the consumption of wildlife found dead by the local population and presence in a domestic animal reveal potential sources of exposure to humans.
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58
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Woodroffe R, Donnelly CA, Ham C, Jackson SYB, Moyes K, Chapman K, Stratton NG, Cartwright SJ. Badgers prefer cattle pasture but avoid cattle: implications for bovine tuberculosis control. Ecol Lett 2016; 19:1201-8. [DOI: 10.1111/ele.12654] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Revised: 06/01/2016] [Accepted: 07/04/2016] [Indexed: 11/28/2022]
Affiliation(s)
- Rosie Woodroffe
- Institute of Zoology; Zoological Society of London; Regent's Park London NW1 4RY UK
| | - Christl A. Donnelly
- Department of Infectious Disease Epidemiology; MRC Centre for Outbreak Analysis and Modelling; Imperial College London; London W2 1PG UK
| | - Cally Ham
- Institute of Zoology; Zoological Society of London; Regent's Park London NW1 4RY UK
| | - Seth Y. B. Jackson
- Institute of Zoology; Zoological Society of London; Regent's Park London NW1 4RY UK
| | - Kelly Moyes
- Institute of Zoology; Zoological Society of London; Regent's Park London NW1 4RY UK
| | - Kayna Chapman
- Institute of Zoology; Zoological Society of London; Regent's Park London NW1 4RY UK
| | - Naomi G. Stratton
- Institute of Zoology; Zoological Society of London; Regent's Park London NW1 4RY UK
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Turner WC, Kausrud KL, Beyer W, Easterday WR, Barandongo ZR, Blaschke E, Cloete CC, Lazak J, Van Ert MN, Ganz HH, Turnbull PCB, Stenseth NC, Getz WM. Lethal exposure: An integrated approach to pathogen transmission via environmental reservoirs. Sci Rep 2016; 6:27311. [PMID: 27265371 PMCID: PMC4893621 DOI: 10.1038/srep27311] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 05/11/2016] [Indexed: 11/09/2022] Open
Abstract
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.
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Affiliation(s)
- Wendy C Turner
- Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, P.O. Box 1066 Blindern, 0361 Oslo, Norway.,Department of Biological Sciences, State University of New York, Albany, New York 12222, USA.,Department of Environmental Science, Policy and Management, University of California, Berkeley, 137 Mulford Hall, Berkeley, CA 94720-3112, USA
| | - Kyrre L Kausrud
- Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, P.O. Box 1066 Blindern, 0361 Oslo, Norway
| | - Wolfgang Beyer
- Institute of Animal Sciences, Department of Environmental and Animal Hygiene, University of Hohenheim, Hohenheim, Germany
| | - W Ryan Easterday
- Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, P.O. Box 1066 Blindern, 0361 Oslo, Norway
| | - Zoë R Barandongo
- Department of Biological Sciences, Faculty of Science, University of Namibia, Windhoek, Namibia
| | - Elisabeth Blaschke
- Institute of Animal Sciences, Department of Environmental and Animal Hygiene, University of Hohenheim, Hohenheim, Germany
| | - Claudine C Cloete
- Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, P.O. Box 1066 Blindern, 0361 Oslo, Norway.,Department of Biological Sciences, Faculty of Science, University of Namibia, Windhoek, Namibia.,Etosha Ecological Institute, Ministry of Environment and Tourism, Etosha National Park, PO Box 6, Okaukuejo, Namibia
| | - Judith Lazak
- Institute of Animal Sciences, Department of Environmental and Animal Hygiene, University of Hohenheim, Hohenheim, Germany.,Institute of International Animal Health, Free University of Berlin, Königsweg 67, 14163 Berlin, Germany
| | - Matthew N Van Ert
- Emerging Pathogens Institute, University of Florida, Gainesville, FL, USA
| | - Holly H Ganz
- Department of Environmental Science, Policy and Management, University of California, Berkeley, 137 Mulford Hall, Berkeley, CA 94720-3112, USA.,Genome Center and Department of Evolution and Ecology, University of California, Davis, CA, USA
| | | | - Nils Chr Stenseth
- Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, P.O. Box 1066 Blindern, 0361 Oslo, Norway
| | - Wayne M Getz
- Department of Environmental Science, Policy and Management, University of California, Berkeley, 137 Mulford Hall, Berkeley, CA 94720-3112, USA.,School of Mathematical Sciences, University of KwaZulu-Natal, Private Bag X54001, Durban 4000, South Africa
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Morris LR, Blackburn JK. Predicting Disease Risk, Identifying Stakeholders, and Informing Control Strategies: A Case Study of Anthrax in Montana. ECOHEALTH 2016; 13:262-73. [PMID: 27169560 PMCID: PMC5965262 DOI: 10.1007/s10393-016-1119-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Revised: 03/14/2016] [Accepted: 03/17/2016] [Indexed: 06/05/2023]
Abstract
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.
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Affiliation(s)
- Lillian R Morris
- Spatial Epidemiology & Ecology Research Laboratory, Department of Geography, University of Florida, 3141 Turlington Hall, PO Box 117315, Gainesville, FL, 32611-7315, USA.
- Emerging Pathogens Institute, University of Florida, 2055 Mowry Road, Gainesville, FL, 32611, USA.
| | - Jason K Blackburn
- Spatial Epidemiology & Ecology Research Laboratory, Department of Geography, University of Florida, 3141 Turlington Hall, PO Box 117315, Gainesville, FL, 32611-7315, USA
- Emerging Pathogens Institute, University of Florida, 2055 Mowry Road, Gainesville, FL, 32611, USA
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Mapping the Distribution of Anthrax in Mainland China, 2005-2013. PLoS Negl Trop Dis 2016; 10:e0004637. [PMID: 27097318 PMCID: PMC4838246 DOI: 10.1371/journal.pntd.0004637] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2015] [Accepted: 03/28/2016] [Indexed: 11/29/2022] Open
Abstract
Background Anthrax, a global re-emerging zoonotic disease in recent years is enzootic in mainland China. Despite its significance to the public health, spatiotemporal distributions of the disease in human and livestock and its potential driving factors remain poorly understood. Methodology/Principal Findings Using the national surveillance data of human and livestock anthrax from 2005 to 2013, we conducted a retrospective epidemiological study and risk assessment of anthrax in mainland China. The potential determinants for the temporal and spatial distributions of human anthrax were also explored. We found that the majority of human anthrax cases were located in six provinces in western and northeastern China, and five clustering areas with higher incidences were identified. The disease mostly peaked in July or August, and males aged 30–49 years had higher incidence than other subgroups. Monthly incidence of human anthrax was positively correlated with monthly average temperature, relative humidity and monthly accumulative rainfall with lags of 0–2 months. A boosted regression trees (BRT) model at the county level reveals that densities of cattle, sheep and human, coverage of meadow, coverage of typical grassland, elevation, coverage of topsoil with pH > 6.1, concentration of organic carbon in topsoil, and the meteorological factors have contributed substantially to the spatial distribution of the disease. The model-predicted probability of occurrence of human cases in mainland China was mapped at the county level. Conclusions/Significance Anthrax in China was characterized by significant seasonality and spatial clustering. The spatial distribution of human anthrax was largely driven by livestock husbandry, human density, land cover, elevation, topsoil features and climate. Enhanced surveillance and intervention for livestock and human anthrax in the high-risk regions, particularly on the Qinghai-Tibetan Plateau, is the key to the prevention of human infections. Anthrax is a worldwide zoonosis affecting mostly grazing herbivores, with occasional spillover to humans who have contact with infected animals or contaminated animal products. We characterized the distributional patterns of both human and livestock anthrax in China from 2005 to 2013, and identified agro-ecological, environmental and meteorological factors contributing to the temporal and spatial distributions of the disease. We found that the spatial distribution of human anthrax in China was mainly driven by densities of cattle, sheep and humans, coverage of meadow, coverage of typical grassland, elevation, pH level of topsoil, concentration of organic carbon in topsoil, and meteorological factors. We also identified the regions with higher probabilities for the occurrence of human cases. Our findings provided a clear qualitative and quantitative understanding of the epidemiological characteristics and risk recognition of anthrax in China, and can be helpful for prioritizing surveillance and control programs in the future.
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Mullins JC, Van Ert M, Hadfield T, Nikolich MP, Hugh-Jones ME, Blackburn JK. Spatio-temporal patterns of an anthrax outbreak in white-tailed deer, Odocoileus virginanus, and associated genetic diversity of Bacillus anthracis. BMC Ecol 2015; 15:23. [PMID: 26669305 PMCID: PMC4681179 DOI: 10.1186/s12898-015-0054-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Accepted: 11/19/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Anthrax, a soil-borne zoonosis caused by the bacterium Bacillus anthracis, is enzootic in areas of North America with frequent outbreaks in west Texas. Despite a long history of study, pathogen transmission during natural outbreaks remains poorly understood. Here we combined case-level spatio-temporal analysis and high resolution genotyping to investigate anthrax transmission dynamics. Carcass locations from a single white-tailed deer, Odocoileus virginanus, outbreak were analyzed for spatial clustering using K-function analysis and directionality with trend surface analysis and the direction test. RESULTS The directionalities were compared to results of high resolution genotyping. The results of the spatial clustering analyses, combined with deer movement data, suggest anthrax transmission events occur within limited spatial areas, with carcass locations occurring within the activity space of adjacent cases. The directionality of the outbreak paralleled adjacent dry river beds. Isolates from the outbreak were represented by a single genotype based on multiple locus variable number tandem repeat analysis (MLVA); four sub-genotypes were identified using single nucleotide repeat (SNR) analysis. CONCLUSIONS Areas of high transmission agreed spatially with areas of higher SNR genetic diversity; however, SNRs did not provide clear evidence of linear transmission. Overlap of case home ranges provides spatial and temporal support for localized transmission, which may include the role of necrophagous or hematophagous flies in outbreaks in this region. These results emphasize the need for active surveillance and prompt cleanup of anthrax carcasses to control anthrax both during outbreaks and between seasons.
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Affiliation(s)
- Jocelyn C Mullins
- Department of Geography, Spatial Epidemiology and Ecology Research Laboratory, University of Florida, Gainesville, FL, USA. .,Emerging Pathogens Institute, University of Florida, Gainesville, USA.
| | - Matthew Van Ert
- Department of Geography, Spatial Epidemiology and Ecology Research Laboratory, University of Florida, Gainesville, FL, USA. .,Emerging Pathogens Institute, University of Florida, Gainesville, USA.
| | - Ted Hadfield
- Emerging Pathogens Institute, University of Florida, Gainesville, USA.
| | - Mikeljon P Nikolich
- Department of Emerging Bacterial Infections, Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, MD, USA.
| | - Martin E Hugh-Jones
- Department of Environmental Sciences, School of the Coast and Environment, Louisiana State University, Baton Rouge, LA, USA.
| | - Jason K Blackburn
- Department of Geography, Spatial Epidemiology and Ecology Research Laboratory, University of Florida, Gainesville, FL, USA. .,Emerging Pathogens Institute, University of Florida, Gainesville, USA.
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63
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Dudley JP, Hang'Ombe BM, Leendertz FH, Dorward LJ, Castro J, Subalusky AL, Clauss M. Carnivory in the common hippopotamus
H
ippopotamus amphibius
: implications for the ecology and epidemiology of anthrax in
A
frican landscapes. Mamm Rev 2015. [DOI: 10.1111/mam.12056] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Joseph P. Dudley
- Leidos Inc. 20201 Century Boulevard Germantown MD 20874 USA
- Institute of Arctic Biology University of Alaska Fairbanks Fairbanks AK 99775‐7000 USA
| | | | | | | | - Julio Castro
- Departamento de Colonia Zorrilla 348 Carmelo Uruguay
| | - Amanda L. Subalusky
- Department of Ecology and Evolutionary Biology Yale University 165 Prospect St. New Haven CT 06511 USA
| | - Marcus Clauss
- Clinic for Zoo Animals Exotic Pets and Wildlife Vetsuisse Faculty University of Zurich Winterthurerstr. 260 8057 Zurich Switzerland
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64
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Goel AK. Anthrax: A disease of biowarfare and public health importance. World J Clin Cases 2015; 3:20-33. [PMID: 25610847 PMCID: PMC4295216 DOI: 10.12998/wjcc.v3.i1.20] [Citation(s) in RCA: 130] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Revised: 10/23/2014] [Accepted: 10/31/2014] [Indexed: 02/05/2023] Open
Abstract
Bioterrorism has received a lot of attention in the first decade of this century. Biological agents are considered attractive weapons for bioterrorism as these are easy to obtain, comparatively inexpensive to produce and exhibit widespread fear and panic than the actual potential of physical damage. Bacillus anthracis (B. anthracis), the etiologic agent of anthrax is a Gram positive, spore forming, non-motile bacterium. This is supposed to be one of the most potent BW agents because its spores are extremely resistant to natural conditions and can survive for several decades in the environment. B. anthracis spores enter the body through skin lesion (cutaneous anthrax), lungs (pulmonary anthrax), or gastrointestinal route (gastrointestinal anthrax) and germinate, giving rise to the vegetative form. Anthrax is a concern of public health also in many countries where agriculture is the main source of income including India. Anthrax has been associated with human history for a very long time and regained its popularity after Sept 2001 incidence in United States. The present review article describes the history, biology, life cycle, pathogenicity, virulence, epidemiology and potential of B. anthracis as biological weapon.
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65
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A One Health, participatory epidemiology assessment of anthrax (Bacillus anthracis) management in Western Uganda. Soc Sci Med 2014; 129:44-50. [PMID: 25066946 DOI: 10.1016/j.socscimed.2014.07.037] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Revised: 04/03/2014] [Accepted: 07/16/2014] [Indexed: 01/21/2023]
Abstract
Sporadic anthrax outbreaks have occurred in and around Uganda's Queen Elizabeth National Park (QENP) for years, affecting wildlife, domestic animals, and humans. Reported outbreaks (2004-2005 and 2010) in QENP collectively killed over 500 wild animals and over 400 domestic animals. A 2011 outbreak in Sheema district temporarily froze local markets while killing two humans and seven bovines. One Health is multidisciplinary at its core, yet studies sometimes focus on the effects of animals on human health to the detriment of investigating the surrounding ecological and cultural contexts. Participatory methods connect problems - such as disease - to their context. A multidisciplinary team used participatory epidemiology and conventional structured questionnaires to investigate the impacts of anthrax on human livelihoods and the related perceptions of conservation, public health, and veterinary health efforts in the QENP area. Proximities to previous anthrax outbreaks and to QENP were treated as risk factors in the collection and evaluation of data. Participants' feedback indicates that anthrax prevalence may be greater than officially reported. Community member perceptions about anthrax and other diseases appear to be more closely related to their proximity to QENP than their proximity to anthrax outbreaks. Neither risk factor had a strong effect on knowledge of disease, nor any effect on behaviors associated with disease response or control. Instead, participants reported that social pressures, the economics of poverty, and the lack of health and veterinary infrastructure highly influenced responses to disease. The complex connections between the social needs and the economic context of these communities seem to be undermining current anthrax control and education measures. This livelihood-based decision-making may be unlikely to respond to educational intervention alone. This study provides a strong base for further research and for improvements in effective disease control.
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66
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Kracalik I, Abdullayev R, Asadov K, Ismayilova R, Baghirova M, Ustun N, Shikhiyev M, Talibzade A, Blackburn JK. Changing patterns of human anthrax in Azerbaijan during the post-Soviet and preemptive livestock vaccination eras. PLoS Negl Trop Dis 2014; 8:e2985. [PMID: 25032701 PMCID: PMC4102439 DOI: 10.1371/journal.pntd.0002985] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2014] [Accepted: 05/16/2014] [Indexed: 11/19/2022] Open
Abstract
We assessed spatial and temporal changes in the occurrence of human anthrax in Azerbaijan during 1984 through 2010. Data on livestock outbreaks, vaccination efforts, and human anthrax incidence during Soviet governance, post-Soviet governance, preemptive livestock vaccination were analyzed. To evaluate changes in the spatio-temporal distribution of anthrax, we used a combination of spatial analysis, cluster detection, and weighted least squares segmented regression. Results indicated an annual percent change in incidence of (+)11.95% from 1984 to 1995 followed by declining rate of -35.24% after the initiation of livestock vaccination in 1996. Our findings also revealed geographic variation in the spatial distribution of reporting; cases were primarily concentrated in the west early in the study period and shifted eastward as time progressed. Over twenty years after the dissolution of the Soviet Union, the distribution of human anthrax in Azerbaijan has undergone marked changes. Despite decreases in the incidence of human anthrax, continued control measures in livestock are needed to mitigate its occurrence. The shifting patterns of human anthrax highlight the need for an integrated "One Health" approach that takes into account the changing geographic distribution of the disease.
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Affiliation(s)
- Ian Kracalik
- Spatial Epidemiology & Ecology Research Laboratory, Department of Geography, University of Florida, Gainesville, Florida, United States of America
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America
| | | | | | | | | | - Narmin Ustun
- Republican Anti-plague Station, Baku, Azerbaijan
| | | | | | - Jason K. Blackburn
- Spatial Epidemiology & Ecology Research Laboratory, Department of Geography, University of Florida, Gainesville, Florida, United States of America
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America
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67
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Cizauskas CA, Bellan SE, Turner WC, Vance RE, Getz WM. Frequent and seasonally variable sublethal anthrax infections are accompanied by short-lived immunity in an endemic system. J Anim Ecol 2014; 83:1078-90. [PMID: 24499424 DOI: 10.1111/1365-2656.12207] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Accepted: 01/25/2014] [Indexed: 01/07/2023]
Abstract
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 more objective. Despite the fact that anthrax is an ancient and emerging zoonotic infectious disease found world-wide, its natural ecology is not well understood. In particular, little is known about the adaptive immune responses of wild herbivore hosts against Bacillus anthracis. Working in the natural anthrax system of Etosha National Park, Namibia, we collected 154 serum samples from plains zebra (Equus quagga), 21 from springbok (Antidorcas marsupialis) and 45 from African elephants (Loxodonta africana) over 2-3 years, resampling individuals when possible for seasonal and longitudinal comparisons. We used enzyme-linked immunosorbent assays to measure anti-anthrax antibody titres and developed three increasingly conservative models to determine endpoint titres with more rigourous, objective mensuration. Between 52 and 87% of zebra, 0-15% of springbok and 3-52% of elephants had measurable anti-anthrax antibody titres, depending on the model used. While the ability of elephants and springbok to mount anti-anthrax adaptive immune responses is still equivocal, our results indicate that zebra in ENP often survive sublethal anthrax infections, encounter most B. anthracis in the wet season and can partially booster their immunity to B. anthracis. Thus, rather than being solely a lethal disease, anthrax often occurs as a sublethal infection in some susceptible hosts. Though we found that adaptive immunity to anthrax wanes rapidly, subsequent and frequent sublethal B. anthracis infections cause maturation of anti-anthrax immunity. By triggering host immune responses, these common sublethal infections may act as immunomodulators and affect population dynamics through indirect immunological and co-infection effects. In addition, with our three endpoint titre models, we introduce more mensuration rigour into serological antibody assays, even under the often-restrictive conditions that come with adapting laboratory immunology methods to wild systems. With these methods, we identified significantly more zebras responding immunologically to anthrax than have previous studies using less comprehensive titre analyses.
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Affiliation(s)
- Carrie A Cizauskas
- Department of Environmental Science, Policy & Management, University of California, Berkeley, Berkeley, CA, USA.,Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA
| | - Steven E Bellan
- Department of Environmental Science, Policy & Management, University of California, Berkeley, Berkeley, CA, USA.,Center for Computational Biology and Informatics, University of Texas at Austin, Austin, TX, USA
| | - Wendy C Turner
- Department of Environmental Science, Policy & Management, University of California, Berkeley, Berkeley, CA, USA.,Department of Biosciences, Centre for Ecological and Evolutionary Synthesis, University of Oslo, Oslo, Norway
| | - Russell E Vance
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Wayne M Getz
- Department of Environmental Science, Policy & Management, University of California, Berkeley, Berkeley, CA, USA.,School of Mathematical Sciences, University of KwaZulu-Natal, Durban, South Africa
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68
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ANTE- AND POSTMORTEM DIAGNOSTIC TECHNIQUES FOR ANTHRAX: RETHINKING PATHOGEN EXPOSURE AND THE GEOGRAPHIC EXTENT OF THE DISEASE IN WILDLIFE. J Wildl Dis 2013; 49:786-801. [DOI: 10.7589/2013-05-126] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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69
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Kracalik IT, Malania L, Tsertsvadze N, Manvelyan J, Bakanidze L, Imnadze P, Tsanava S, Blackburn JK. Evidence of local persistence of human anthrax in the country of georgia associated with environmental and anthropogenic factors. PLoS Negl Trop Dis 2013; 7:e2388. [PMID: 24040426 PMCID: PMC3764226 DOI: 10.1371/journal.pntd.0002388] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Accepted: 07/17/2013] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Anthrax is a soil-borne disease caused by the bacterium Bacillus anthracis and is considered a neglected zoonosis. In the country of Georgia, recent reports have indicated an increase in the incidence of human anthrax. Identifying sub-national areas of increased risk may help direct appropriate public health control measures. The purpose of this study was to evaluate the spatial distribution of human anthrax and identify environmental/anthropogenic factors associated with persistent clusters. METHODS/FINDINGS A database of human cutaneous anthrax in Georgia during the period 2000-2009 was constructed using a geographic information system (GIS) with case data recorded to the community location. The spatial scan statistic was used to identify persistence of human cutaneous anthrax. Risk factors related to clusters of persistence were modeled using a multivariate logistic regression. Areas of persistence were identified in the southeastern part of the country. Results indicated that the persistence of human cutaneous anthrax showed a strong positive association with soil pH and urban areas. CONCLUSIONS/SIGNIFICANCE Anthrax represents a persistent threat to public and veterinary health in Georgia. The findings here showed that the local level heterogeneity in the persistence of human cutaneous anthrax necessitates directed interventions to mitigate the disease. High risk areas identified in this study can be targeted for public health control measures such as farmer education and livestock vaccination campaigns.
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Affiliation(s)
- Ian T. Kracalik
- Spatial Epidemiology and Ecology Research Lab, Department of Geography, University of Florida, Gainesville, Florida, United States of America
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America
| | - Lile Malania
- National Center for Disease Control and Public Health, Tbilisi, Georgia
| | | | | | | | - Paata Imnadze
- National Center for Disease Control and Public Health, Tbilisi, Georgia
| | - Shota Tsanava
- National Center for Disease Control and Public Health, Tbilisi, Georgia
| | - Jason K. Blackburn
- Spatial Epidemiology and Ecology Research Lab, Department of Geography, University of Florida, Gainesville, Florida, United States of America
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America
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70
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Sinclair ARE, Metzger KL, Fryxell JM, Packer C, Byrom AE, Craft ME, Hampson K, Lembo T, Durant SM, Forrester GJ, Bukombe J, Mchetto J, Dempewolf J, Hilborn R, Cleaveland S, Nkwabi A, Mosser A, Mduma SAR. Asynchronous food-web pathways could buffer the response of Serengeti predators to El Niño Southern Oscillation. Ecology 2013; 94:1123-30. [PMID: 23858652 DOI: 10.1890/12-0428.1] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Understanding how entire ecosystems maintain stability in the face of climatic and human disturbance is one of the most fundamental challenges in ecology. Theory suggests that a crucial factor determining the degree of ecosystem stability is simply the degree of synchrony with which different species in ecological food webs respond to environmental stochasticity. Ecosystems in which all food-web pathways are affected similarly by external disturbance should amplify variability in top carnivore abundance over time due to population interactions, whereas ecosystems in which a large fraction of pathways are nonresponsive or even inversely responsive to external disturbance will have more constant levels of abundance at upper trophic levels. To test the mechanism underlying this hypothesis, we used over half a century of demographic data for multiple species in the Serengeti (Tanzania) ecosystem to measure the degree of synchrony to variation imposed by an external environmental driver, the El Niño Southern Oscillation (ENSO). ENSO effects were mediated largely via changes in dry-season vs. wet-season rainfall and consequent changes in vegetation availability, propagating via bottom-up effects to higher levels of the Serengeti food web to influence herbivores, predators and parasites. Some species in the Serengeti food web responded to the influence of ENSO in opposite ways, whereas other species were insensitive to variation in ENSO. Although far from conclusive, our results suggest that a diffuse mixture of herbivore responses could help buffer top carnivores, such as Serengeti lions, from variability in climate. Future global climate changes that favor some pathways over others, however, could alter the effectiveness of such processes in the future.
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Affiliation(s)
- A R E Sinclair
- Biodiversity Research Centre, University of British Columbia, Vancouver, British Columbia, V6T 1Z4 Canada
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Turner WC, Imologhome P, Havarua Z, Kaaya GP, Mfune JKE, Mpofu IDT, Getz WM. Soil ingestion, nutrition and the seasonality of anthrax in herbivores of Etosha National Park. Ecosphere 2013. [DOI: 10.1890/es12-00245.1] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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72
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Ganz HH, Karaoz U, Getz WM, Versfeld W, Brodie EL. Diversity and structure of soil bacterial communities associated with vultures in an African savanna. Ecosphere 2012. [DOI: 10.1890/es11-00333.1] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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