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Spatiotemporal Variations of Plague Risk in the Tibetan Plateau from 1954-2016. BIOLOGY 2022; 11:biology11020304. [PMID: 35205170 PMCID: PMC8869688 DOI: 10.3390/biology11020304] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 02/08/2022] [Accepted: 02/09/2022] [Indexed: 11/17/2022]
Abstract
Plague persists in the plague natural foci today. Although previous studies have found climate drives plague dynamics, quantitative analysis on animal plague risk under climate change remains understudied. Here, we analyzed plague dynamics in the Tibetan Plateau (TP) which is a climate-sensitive area and one of the most severe animal plague areas in China to disentangle variations in marmot plague enzootic foci, diffusion patterns, and their possible links with climate and anthropogenic factors. Specifically, we developed a time-sharing ecological niche modelling framework to identify finer potential plague territories and their temporal epidemic trends. Models were conducted by assembling animal records and multi-source ecophysiological variables with actual ecological effects (both climatic predictors and landscape factors) and driven by matching plague strains to periods corresponding to meteorological datasets. The models identified abundant animal plague territories over the TP and suggested the spatial patterns varied spatiotemporal dimension across the years, undergoing repeated spreading and contractions. Plague risk increased in the 1980s and 2000s, with the risk area increasing by 17.7 and 55.5 thousand km2, respectively. The 1990s and 2010s were decades of decreased risk, with reductions of 71.9 and 39.5 thousand km2, respectively. Further factor analysis showed that intrinsic conditions (i.e., elevation, soil, and geochemical landscape) provided fundamental niches. In contrast, climatic conditions, especially precipitation, led to niche differentiation and resulted in varied spatial patterns. Additionally, while increased human interference may temporarily reduce plague risks, there is a strong possibility of recurrence. This study reshaped the plague distribution at multiple time scales in the TP and revealed multifactorial synergistic effects on the spreading and contraction of plague foci, confirming that TP plague is increasingly sensitive to climate change. These findings may facilitate groups to take measures to combat the plague threats and prevent potential future human plague from occurring.
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Vallès X, Stenseth NC, Demeure C, Horby P, Mead PS, Cabanillas O, Ratsitorahina M, Rajerison M, Andrianaivoarimanana V, Ramasindrazana B, Pizarro-Cerda J, Scholz HC, Girod R, Hinnebusch BJ, Vigan-Womas I, Fontanet A, Wagner DM, Telfer S, Yazdanpanah Y, Tortosa P, Carrara G, Deuve J, Belmain SR, D’Ortenzio E, Baril L. Human plague: An old scourge that needs new answers. PLoS Negl Trop Dis 2020; 14:e0008251. [PMID: 32853251 PMCID: PMC7451524 DOI: 10.1371/journal.pntd.0008251] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Yersinia pestis, the bacterial causative agent of plague, remains an important threat to human health. Plague is a rodent-borne disease that has historically shown an outstanding ability to colonize and persist across different species, habitats, and environments while provoking sporadic cases, outbreaks, and deadly global epidemics among humans. Between September and November 2017, an outbreak of urban pneumonic plague was declared in Madagascar, which refocused the attention of the scientific community on this ancient human scourge. Given recent trends and plague's resilience to control in the wild, its high fatality rate in humans without early treatment, and its capacity to disrupt social and healthcare systems, human plague should be considered as a neglected threat. A workshop was held in Paris in July 2018 to review current knowledge about plague and to identify the scientific research priorities to eradicate plague as a human threat. It was concluded that an urgent commitment is needed to develop and fund a strong research agenda aiming to fill the current knowledge gaps structured around 4 main axes: (i) an improved understanding of the ecological interactions among the reservoir, vector, pathogen, and environment; (ii) human and societal responses; (iii) improved diagnostic tools and case management; and (iv) vaccine development. These axes should be cross-cutting, translational, and focused on delivering context-specific strategies. Results of this research should feed a global control and prevention strategy within a "One Health" approach.
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Affiliation(s)
- Xavier Vallès
- Epidemiology and Clinical Research Unit, Institut Pasteur de Madagascar, Antananarivo, Madagascar
| | - Nils Chr. Stenseth
- Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, Oslo, Norway
- Key Laboratory for Earth System Modelling, Department of Earth System Science, Tsinghua University, Beijing, China
| | - Christian Demeure
- Yersinia Research Unit, National Reference Centre “Plague & Other Yersinioses,” WHO Collaborating Research and Reference Centre for Yersinia, Institut Pasteur, Paris, France
| | - Peter Horby
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Paul S. Mead
- Bacterial Diseases Branch, Division of Vector Borne Diseases, Centers for Disease Control and Prevention, Fort Collins, Colorado, United States of America
| | - Oswaldo Cabanillas
- Control de Epidemia Desastres y Otras Emergencias Sanitarias, Oficina General de Epidemiologia, Ministerio de Salud, Perúu
| | - Mahery Ratsitorahina
- Epidemiology and Clinical Research Unit, Institut Pasteur de Madagascar, Antananarivo, Madagascar
| | - Minoarisoa Rajerison
- Plague Unit, Central Laboratory for Plague, Institut Pasteur de Madagascar, Antananarivo, Madagascar
| | | | - Beza Ramasindrazana
- Plague Unit, Central Laboratory for Plague, Institut Pasteur de Madagascar, Antananarivo, Madagascar
| | - Javier Pizarro-Cerda
- Yersinia Research Unit, National Reference Centre “Plague & Other Yersinioses,” WHO Collaborating Research and Reference Centre for Yersinia, Institut Pasteur, Paris, France
| | - Holger C. Scholz
- Reference Laboratory for Plague, Bundeswehr Institute of Microbiology, Munich, Germany
| | - Romain Girod
- Medical Entomology Unit, Institut Pasteur de Madagascar, Antananarivo, Madagascar
| | - B. Joseph Hinnebusch
- Rocky Mountain Laboratories, National Institute of Health, National Institutes of Allergy and Infectious Diseases, Hamilton, Montana, United States of America
| | - Ines Vigan-Womas
- Immunology of Infectious Diseases Unit, Institut Pasteur de Madagascar, Antananarivo, Madagascar
| | - Arnaud Fontanet
- Emerging Diseases Epidemiology Unit, Institut Pasteur, Paris, France
- PACRI unit, Conservatoire National des Arts et Métiers, Paris, France
| | - David M. Wagner
- The Pathogen and Microbiome Institute, Northern Arizona University, Flagstaff, Arizona, United States of America
| | - Sandra Telfer
- School of Biological Sciences, University of Aberdeen, Aberdeen, United Kingdom
| | - Yazdan Yazdanpanah
- REACTing, Inserm, Université Paris-Diderot, Sorbonne Paris Cité, Paris, France
- Service de Maladies Infectieuses et Tropicales, Hôpital Bichat-Claude Bernard, AP-HP, Paris, France
| | - Pablo Tortosa
- Université de La Réunion, Unité Mixte de Recherche Processus Infectieux en Milieu Insulaire Tropical, La Réunion, France
| | - Guia Carrara
- REACTing, Inserm, Université Paris-Diderot, Sorbonne Paris Cité, Paris, France
| | - Jane Deuve
- Department of International Affairs, Institut Pasteur, Paris, France
| | - Steven R. Belmain
- Natural Resources Institute, University of Greenwich, Chatham Maritime, Kent, United Kingdom
| | - Eric D’Ortenzio
- REACTing, Inserm, Université Paris-Diderot, Sorbonne Paris Cité, Paris, France
- Service de Maladies Infectieuses et Tropicales, Hôpital Bichat-Claude Bernard, AP-HP, Paris, France
| | - Laurence Baril
- Epidemiology and Clinical Research Unit, Institut Pasteur de Madagascar, Antananarivo, Madagascar
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Movement patterns of free-roaming dogs on heterogeneous urban landscapes: Implications for rabies control. Prev Vet Med 2020; 178:104978. [PMID: 32302776 DOI: 10.1016/j.prevetmed.2020.104978] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 02/07/2020] [Accepted: 03/24/2020] [Indexed: 12/25/2022]
Abstract
In 2015, a case of canine rabies in Arequipa, Peru indicated the re-emergence of rabies virus in the city. Despite mass dog vaccination campaigns across the city and reactive ring vaccination and other control activities around positive cases (e.g. elimination of unowned dogs), the outbreak has spread. Here we explore how the urban landscape of Arequipa affects the movement patterns of free-roaming dogs, the main reservoirs of the rabies virus in the area. We tracked 23 free-roaming dogs using Global Positioning System (GPS) collars. We analyzed the spatio-temporal GPS data using the time- local convex hull method. Dog movement patterns varied across local environments. We found that water channels, an urban feature of Arequipa that are dry most of the year, promote movement. Dogs that used the water channels extensively move on average 7 times further (p = 0.002) and 1.2 times more directionally (p = 0.027) than dogs that do not use the water channels at all. They were also 1.3 times faster on average, but this difference was not statistically significant (p = 0.197). Our findings suggest that water channels can be used by dogs as 'highways' to transverse the city and have the potential to spread disease far beyond the radius of control practices. Control efforts should focus on a robust vaccination campaign attuned to the geography of the city, and not limited to small-scale rings surrounding cases.
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Jones SD, Atshabar B, Schmid BV, Zuk M, Amramina A, Stenseth NC. Living with plague: Lessons from the Soviet Union's antiplague system. Proc Natl Acad Sci U S A 2019; 116:9155-9163. [PMID: 31061115 PMCID: PMC6511024 DOI: 10.1073/pnas.1817339116] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Zoonoses, such as plague, are primarily animal diseases that spill over into human populations. While the goal of eradicating such diseases is enticing, historical experience validates abandoning eradication in favor of ecologically based control strategies (which reduce morbidity and mortality to a locally accepted risk level). During the 20th century, one of the most extensive plague-eradication efforts in recorded history was undertaken to enable large-scale changes in land use in the former Soviet Union (including vast areas of central Asia). Despite expending tremendous resources in its attempt to eradicate plague, the Soviet antiplague response gradually abandoned the goal of eradication in favor of plague control linked with developing basic knowledge of plague ecology. Drawing from this experience, we combine new gray-literature sources, historical and recent research, and fieldwork to outline best practices for the control of spillover from zoonoses while minimally disrupting wildlife ecosystems, and we briefly compare the Soviet case with that of endemic plague in the western United States. We argue for the allocation of sufficient resources to maintain ongoing local surveillance, education, and targeted control measures; to incorporate novel technologies selectively; and to use ecological research to inform developing landscape-based models for transmission interruption. We conclude that living with emergent and reemergent zoonotic diseases-switching to control-opens wider possibilities for interrupting spillover while preserving natural ecosystems, encouraging adaptation to local conditions, and using technological tools judiciously and in a cost-effective way.
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Affiliation(s)
- Susan D Jones
- Department of Ecology, Evolution & Behavior, University of Minnesota, St. Paul, MN 55108;
- Program in History of Science & Technology, University of Minnesota, St. Paul, MN 55108
| | - Bakyt Atshabar
- M. Aikimbayev's Kazakh Scientific Centre for Quarantine and Zoonotic Diseases, Ministry of Public Health, Almaty 480074, Republic of Kazakhstan
| | - Boris V Schmid
- Centre for Ecological and Evolutionary Synthesis, Department of Biosciences, University of Oslo, N-01316 Oslo, Norway
| | - Marlene Zuk
- Department of Ecology, Evolution & Behavior, University of Minnesota, St. Paul, MN 55108
| | - Anna Amramina
- Program in History of Science & Technology, University of Minnesota, St. Paul, MN 55108
| | - Nils Chr Stenseth
- Centre for Ecological and Evolutionary Synthesis, Department of Biosciences, University of Oslo, N-01316 Oslo, Norway;
- Ministry of Education Key Laboratory for Earth System Modeling, Department of Earth System Science, Tsinghua University, Beijing 100084, China
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ZEPPELINI CAIOG, DE ALMEIDA ALZIRAM, CORDEIRO-ESTRELA PEDRO. Ongoing quiescence in the Borborema Plateau Plague focus (Paraiba, Brazil). ACTA ACUST UNITED AC 2018; 90:3007-3015. [DOI: 10.1590/0001-3765201820170977] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 04/04/2018] [Indexed: 01/14/2023]
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Detecting plague-host abundance from space: Using a spectral vegetation index to identify occupancy of great gerbil burrows. ACTA ACUST UNITED AC 2018; 64:249-255. [PMID: 29399006 PMCID: PMC5763245 DOI: 10.1016/j.jag.2017.09.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In Kazakhstan, plague outbreaks occur when its main host, the great gerbil, exceeds an abundance threshold. These live in family groups in burrows, which can be mapped using remote sensing. Occupancy (percentage of burrows occupied) is a good proxy for abundance and hence the possibility of an outbreak. Here we use time series of satellite images to estimate occupancy remotely. In April and September 2013, 872 burrows were identified in the field as either occupied or empty. For satellite images acquired between April and August, 'burrow objects' were identified and matched to the field burrows. The burrow objects were represented by 25 different polygon types, then classified (using a majority vote from 10 Random Forests) as occupied or empty, using Normalized Difference Vegetation Indices (NDVI) calculated for all images. Throughout the season NDVI values were higher for empty than for occupied burrows. Occupancy status of individual burrows that were continuously occupied or empty, was classified with producer's and user's accuracy values of 63 and 64% for the optimum polygon. Occupancy level was predicted very well and differed 2% from the observed occupancy. This establishes firmly the principle that occupancy can be estimated using satellite images with the potential to predict plague outbreaks over extensive areas with much greater ease and accuracy than previously.
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Sansyzbayev Y, Nurmakhanov T, Berdibekov A, Vilkova A, Yeskhodzhayev O, St John HK, Jiang J, Farris CM, Richards AL. Survey for Rickettsiae Within Fleas of Great Gerbils, Almaty Oblast, Kazakhstan. Vector Borne Zoonotic Dis 2016; 17:172-178. [PMID: 27992288 DOI: 10.1089/vbz.2016.2049] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
Little is known of the endemicity of flea-borne rickettsiae in Kazakhstan. Thus, a survey for rickettsiae within great gerbil fleas was conducted in Almaty oblast. High prevalence of Rickettsia asembonensis was detected among Xenopsylla gerbilli, demonstrating that flea-borne rickettsiae are endemic to southeastern Kazakhstan. Interestingly, no Rickettsia typhi were detected in these same fleas.
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Affiliation(s)
- Yerlan Sansyzbayev
- 1 Kazakh Scientific Center for Quarantine and Zoonotic Disease , Almaty, Kazakhstan
| | - Talgat Nurmakhanov
- 1 Kazakh Scientific Center for Quarantine and Zoonotic Disease , Almaty, Kazakhstan
| | - Almas Berdibekov
- 1 Kazakh Scientific Center for Quarantine and Zoonotic Disease , Almaty, Kazakhstan
| | - Anna Vilkova
- 1 Kazakh Scientific Center for Quarantine and Zoonotic Disease , Almaty, Kazakhstan
| | - Olzhas Yeskhodzhayev
- 1 Kazakh Scientific Center for Quarantine and Zoonotic Disease , Almaty, Kazakhstan
| | | | - Ju Jiang
- 2 Naval Medical Research Center , Silver Spring, Maryland
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Laperrière V, Brugger K, Rubel F. Cross-scale modeling of a vector-borne disease, from the individual to the metapopulation: The seasonal dynamics of sylvatic plague in Kazakhstan. Ecol Modell 2016. [DOI: 10.1016/j.ecolmodel.2016.09.023] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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Zeppelini CG, de Almeida AMP, Cordeiro-Estrela P. Zoonoses As Ecological Entities: A Case Review of Plague. PLoS Negl Trop Dis 2016; 10:e0004949. [PMID: 27711205 PMCID: PMC5053604 DOI: 10.1371/journal.pntd.0004949] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
As a zoonosis, Plague is also an ecological entity, a complex system of ecological interactions between the pathogen, the hosts, and the spatiotemporal variations of its ecosystems. Five reservoir system models have been proposed: (i) assemblages of small mammals with different levels of susceptibility and roles in the maintenance and amplification of the cycle; (ii) species-specific chronic infection models; (ii) flea vectors as the true reservoirs; (iii) Telluric Plague, and (iv) a metapopulation arrangement for species with a discrete spatial organization, following a source-sink dynamic of extinction and recolonization with naïve potential hosts. The diversity of the community that harbors the reservoir system affects the transmission cycle by predation, competition, and dilution effect. Plague has notable environmental constraints, depending on altitude (500+ meters), warm and dry climates, and conditions for high productivity events for expansion of the transmission cycle. Human impacts are altering Plague dynamics by altering landscape and the faunal composition of the foci and adjacent areas, usually increasing the presence and number of human cases and outbreaks. Climatic change is also affecting the range of its occurrence. In the current transitional state of zoonosis as a whole, Plague is at risk of becoming a public health problem in poor countries where ecosystem erosion, anthropic invasion of new areas, and climate change increase the contact of the population with reservoir systems, giving new urgency for ecologic research that further details its maintenance in the wild, the spillover events, and how it links to human cases.
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Affiliation(s)
- Caio Graco Zeppelini
- Programa de Pós-Graduação em Ciências Biológicas, Centro de Ciências Exatas e da Natureza, Universidade Federal da Paraíba, Campus I, João Pessoa, Paraíba, Brazil
- Laboratório de Mamíferos, Departamento de Sistemática e Ecologia, Centro de Ciências Exatas e da Natureza, Universidade Federal da Paraíba, Campus I, João Pessoa, Paraíba, Brazil
| | - Alzira Maria Paiva de Almeida
- Centro de Pesquisa Aggeu Magalhães Fiocruz, Campus da Universidade Federal de Pernambuco, Recife, Pernambuco, Brazil
| | - Pedro Cordeiro-Estrela
- Programa de Pós-Graduação em Ciências Biológicas, Centro de Ciências Exatas e da Natureza, Universidade Federal da Paraíba, Campus I, João Pessoa, Paraíba, Brazil
- Laboratório de Mamíferos, Departamento de Sistemática e Ecologia, Centro de Ciências Exatas e da Natureza, Universidade Federal da Paraíba, Campus I, João Pessoa, Paraíba, Brazil
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Li YF, Li DB, Shao HS, Li HJ, Han YD. Plague in China 2014-All sporadic case report of pneumonic plague. BMC Infect Dis 2016; 16:85. [PMID: 26895880 PMCID: PMC4759734 DOI: 10.1186/s12879-016-1403-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Accepted: 02/01/2016] [Indexed: 01/11/2023] Open
Abstract
Background Yersinia pestis is the pathogen of the plague and caused three pandemics worldwide. Pneumonic plague is rarer than bubonic and septicemic plague. We report detailed clinical and pathogenic data for all the three sporadic cases of pneumonic plagues in China in 2014. Case presentation All the three patients are herders in Gansu province of China. They were all infected by Yersinia pestis and displayed in the form of pneumonic plague respectively without related. We tested patient specimens from the upper (nasopharyngeal swabs) or the lower (sputum) respiratory tract and whole blood, plasma, and serum specimens for Yersinia pestis. All patients had fever, cough and dyspnea, and for patient 2 and 3, unconscious. Respiratory symptoms were predominant with acute respiratory failure. The chest X-ray showed signs consistent with necrotizing inflammation with multiple lobar involvements. Despite emergency treatment, all patients died of refractory multiple organ failure within 24 h after admission to hospital. All the contacts were quarantined immediately and there were no secondary cases. Conclusions Nowadays, the plague is epidemic in animals and can infect people who contact with the infected animals which may cause an epidemic in human. We think dogs maybe an intermediate vector for plague and as a source of risk for humans who are exposed to pet animals or who work professionally with canines. If a patient has been exposed to a risk factor and has fever and dyspnea, plague should be considered. People who had contact with a confirmed case should be isolated and investigated for F1 antigen analysis and receive post-exposure preventive treatment. A vaccination strategy might be useful for individuals who are occupationally exposed in areas where endemically infected reservoirs of plague-infected small mammals co-exist.
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Affiliation(s)
- Yun-Fang Li
- Radiology Department, Beijing YouAn Hospital, Capital Medical University, Beijing, 100069, China.
| | - De-Biao Li
- Radiology Department, the First People's Hospital of Yumen, Gansu, China.
| | - Hong-Sheng Shao
- Department of Interventional Radiology, Rehabilitation Center Hospital, of Gansu Province, Gansu, China.
| | - Hong-Jun Li
- Radiology Department, Beijing YouAn Hospital, Capital Medical University, Beijing, 100069, China.
| | - Yue-Dong Han
- Imaging Diagnostic Center, Lanzhou General Hospital, Lanzhou Command, PLA, Lanzhou, 730050, China.
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Levick B, Laudisoit A, Wilschut L, Addink E, Ageyev V, Yeszhanov A, Sapozhnikov V, Belayev A, Davydova T, Eagle S, Begon M. The Perfect Burrow, but for What? Identifying Local Habitat Conditions Promoting the Presence of the Host and Vector Species in the Kazakh Plague System. PLoS One 2015; 10:e0136962. [PMID: 26325073 PMCID: PMC4556633 DOI: 10.1371/journal.pone.0136962] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Accepted: 08/10/2015] [Indexed: 01/14/2023] Open
Abstract
INTRODUCTION The wildlife plague system in the Pre-Balkhash desert of Kazakhstan has been a subject of study for many years. Much progress has been made in generating a method of predicting outbreaks of the disease (infection by the gram negative bacterium Yersinia pestis) but existing methods are not yet accurate enough to inform public health planning. The present study aimed to identify characteristics of individual mammalian host (Rhombomys opimus) burrows related to and potentially predictive of the presence of R.opimus and the dominant flea vectors (Xenopsylla spp.). METHODS Over four seasons, burrow characteristics, their current occupancy status, and flea and tick burden of the occupants were recorded in the field. A second data set was generated of long term occupancy trends by recording the occupancy status of specific burrows over multiple occasions. Generalised linear mixed models were constructed to identify potential burrow properties predictive of either occupancy or flea burden. RESULTS At the burrow level, it was identified that a burrow being occupied by Rhombomys, and remaining occupied, were both related to the characteristics of the sediment in which the burrow was constructed. The flea burden of Rhombomys in a burrow was found to be related to the tick burden. Further larger scale properties were also identified as being related to both Rhombomys and flea presence, including latitudinal position and the season. CONCLUSIONS Therefore, in advancing our current predictions of plague in Kazakhstan, we must consider the landscape at this local level to increase our accuracy in predicting the dynamics of gerbil and flea populations. Furthermore this demonstrates that in other zoonotic systems, it may be useful to consider the distribution and location of suitable habitat for both host and vector species at this fine scale to accurately predict future epizootics.
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Affiliation(s)
- Bethany Levick
- Ecology, Evolution and Genomics of Infectious Disease Research Group, Institute of Integrative Biology, University of Liverpool, Liverpool, United Kingdom
| | - Anne Laudisoit
- Ecology, Evolution and Genomics of Infectious Disease Research Group, Institute of Integrative Biology, University of Liverpool, Liverpool, United Kingdom
| | - Liesbeth Wilschut
- Department of Physical Geography, Utrecht University, Utrecht, The Netherlands
| | - Elisabeth Addink
- Department of Physical Geography, Utrecht University, Utrecht, The Netherlands
| | - Vladimir Ageyev
- M.Akimbayev’s Kazakh Science Centre for Quarantine and Zoonotic Diseases, Almaty, Kazakhstan
| | - Aidyn Yeszhanov
- M.Akimbayev’s Kazakh Science Centre for Quarantine and Zoonotic Diseases, Almaty, Kazakhstan
| | - Valerij Sapozhnikov
- M.Akimbayev’s Kazakh Science Centre for Quarantine and Zoonotic Diseases, Almaty, Kazakhstan
| | - Alexander Belayev
- M.Akimbayev’s Kazakh Science Centre for Quarantine and Zoonotic Diseases, Almaty, Kazakhstan
- Taldykorgan anti-plague station, Taldykorgan, Kazakhstan
| | - Tania Davydova
- Taldykorgan anti-plague station, Taldykorgan, Kazakhstan
| | - Sally Eagle
- Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom
| | - Mike Begon
- Ecology, Evolution and Genomics of Infectious Disease Research Group, Institute of Integrative Biology, University of Liverpool, Liverpool, United Kingdom
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12
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Wilschut LI, Laudisoit A, Hughes NK, Addink EA, de Jong SM, Heesterbeek HAP, Reijniers J, Eagle S, Dubyanskiy VM, Begon M. Spatial distribution patterns of plague hosts: point pattern analysis of the burrows of great gerbils in Kazakhstan. JOURNAL OF BIOGEOGRAPHY 2015; 42:1281-1292. [PMID: 26877580 PMCID: PMC4737218 DOI: 10.1111/jbi.12534] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
AIM The spatial structure of a population can strongly influence the dynamics of infectious diseases, yet rarely is the underlying structure quantified. A case in point is plague, an infectious zoonotic disease caused by the bacterium Yersinia pestis. Plague dynamics within the Central Asian desert plague focus have been extensively modelled in recent years, but always with strong uniformity assumptions about the distribution of its primary reservoir host, the great gerbil (Rhombomys opimus). Yet, while clustering of this species' burrows due to social or ecological processes could have potentially significant effects on model outcomes, there is currently nothing known about the spatial distribution of inhabited burrows. Here, we address this knowledge gap by describing key aspects of the spatial patterns of great gerbil burrows in Kazakhstan. LOCATION Kazakhstan. METHODS Burrows were classified as either occupied or empty in 98 squares of four different sizes: 200 m (side length), 250 m, 500 m and 590-1020 m. We used Ripley's K statistic to determine whether and at what scale there was clustering of occupied burrows, and semi-variograms to quantify spatial patterns in occupied burrows at scales of 250 m to 9 km. RESULTS Significant spatial clustering of occupied burrows occurred in 25% and 75% of squares of 500 m and 590-1020 m, respectively, but not in smaller squares. In clustered squares, the clustering criterion peaked around 250 m. Semi-variograms showed that burrow density was auto-correlated up to a distance of 7 km and occupied density up to 2.5 km. MAIN CONCLUSIONS These results demonstrate that there is statistically significant spatial clustering of occupied burrows and that the uniformity assumptions of previous plague models should be reconsidered to assess its significance for plague transmission. This field evidence will allow for more realistic approaches to disease ecology models for both this system and for other structured host populations.
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Affiliation(s)
- Liesbeth I Wilschut
- Department of Physical Geography Utrecht University Utrecht The Netherlands; Faculty of Veterinary Medicine Utrecht University Utrecht The Netherlands
| | - Anne Laudisoit
- Ecology Evolution and Genomics of Infectious Disease Research Group Institute of Integrative Biology The University of Liverpool Liverpool UK
| | - Nelika K Hughes
- Evolutionary Ecology Group Department of Biology University of Antwerp Antwerp Belgium
| | - Elisabeth A Addink
- Department of Physical Geography Utrecht University Utrecht The Netherlands
| | - Steven M de Jong
- Department of Physical Geography Utrecht University Utrecht The Netherlands
| | | | - Jonas Reijniers
- Evolutionary Ecology Group Department of Biology University of Antwerp Antwerp Belgium
| | - Sally Eagle
- Ecology Evolution and Genomics of Infectious Disease Research Group Institute of Integrative Biology The University of Liverpool Liverpool UK
| | | | - Mike Begon
- Ecology Evolution and Genomics of Infectious Disease Research Group Institute of Integrative Biology The University of Liverpool Liverpool UK
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