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Xu L, Wang Q, Yang R, Ganbold D, Tsogbadrakh N, Dong K, Liu M, Altantogtokh D, Liu Q, Undrakhbold S, Boldgiv B, Liang W, Stenseth NC. Climate-driven marmot-plague dynamics in Mongolia and China. Sci Rep 2023; 13:11906. [PMID: 37488160 PMCID: PMC10366125 DOI: 10.1038/s41598-023-38966-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 07/18/2023] [Indexed: 07/26/2023] Open
Abstract
The incidence of plague has rebounded in the Americas, Asia, and Africa alongside rapid globalization and climate change. Previous studies have shown local climate to have significant nonlinear effects on plague dynamics among rodent communities. We analyzed an 18-year database of plague, spanning 1998 to 2015, in the foci of Mongolia and China to trace the associations between marmot plague and climate factors. Our results suggested a density-dependent effect of precipitation and a geographic location-dependent effect of temperature on marmot plague. That is, a significantly positive relationship was evident between risk of plague and precipitation only when the marmot density exceeded a certain threshold. The geographical heterogeneity of the temperature effect and the contrasting slopes of influence for the Qinghai-Tibet Plateau (QTP) and other regions in the study (nQTP) were primarily related to diversity of climate and landscape types.
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Affiliation(s)
- Lei Xu
- Vanke School of Public Health, Tsinghua University, Beijing, 100084, China
| | - Qian Wang
- Vanke School of Public Health, Tsinghua University, Beijing, 100084, China
| | - Ruifu Yang
- Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, China
| | - Dalantai Ganbold
- National Center for Zoonotic Diseases, Ulaanbaatar, 211137, Mongolia
| | | | - Kaixing Dong
- Vanke School of Public Health, Tsinghua University, Beijing, 100084, China
| | - Min Liu
- Department of Epidemiology and Biostatistics, School of Public Health, Peking University, Beijing, 100191, China
| | | | - Qiyong Liu
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Changping, Beijing, 102206, China
| | - Sainbileg Undrakhbold
- Professional Biological Society of Mongolia, Ulaanbaatar, 14201, Mongolia
- Department of Biology, National University of Mongolia, Ulaanbaatar, 14201, Mongolia
| | - Bazartseren Boldgiv
- Department of Biology, National University of Mongolia, Ulaanbaatar, 14201, Mongolia.
| | - Wannian Liang
- Vanke School of Public Health, Tsinghua University, Beijing, 100084, China.
| | - Nils Chr Stenseth
- Vanke School of Public Health, Tsinghua University, Beijing, 100084, China.
- The Centre for Pandemics and One-Health Research, Faculty of Medicine, University of Oslo, Oslo, Norway.
- Centre for Ecological and Evolutionary Synthesis, Department of Biosciences, Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway.
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2
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Mitchell CL, Schwarzer AR, Miarinjara A, Jarrett CO, Luis AD, Hinnebusch BJ. A Role for Early-Phase Transmission in the Enzootic Maintenance of Plague. PLoS Pathog 2022; 18:e1010996. [PMID: 36520713 PMCID: PMC9754260 DOI: 10.1371/journal.ppat.1010996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Accepted: 11/10/2022] [Indexed: 12/23/2022] Open
Abstract
Yersinia pestis, the bacterial agent of plague, is enzootic in many parts of the world within wild rodent populations and is transmitted by different flea vectors. The ecology of plague is complex, with rodent hosts exhibiting varying susceptibilities to overt disease and their fleas exhibiting varying levels of vector competence. A long-standing question in plague ecology concerns the conditions that lead to occasional epizootics among susceptible rodents. Many factors are involved, but a major one is the transmission efficiency of the flea vector. In this study, using Oropsylla montana (a ground squirrel flea that is a major plague vector in the western United States), we comparatively quantified the efficiency of the two basic modes of flea-borne transmission. Transmission efficiency by the early-phase mechanism was strongly affected by the host blood source. Subsequent biofilm-dependent transmission by blocked fleas was less influenced by host blood and was more efficient. Mathematical modeling predicted that early-phase transmission could drive an epizootic only among highly susceptible rodents with certain blood characteristics, but that transmission by blocked O. montana could do so in more resistant hosts irrespective of their blood characteristics. The models further suggested that for most wild rodents, exposure to sublethal doses of Y. pestis transmitted during the early phase may restrain rapid epizootic spread by increasing the number of immune, resistant individuals in the population.
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Affiliation(s)
- Cedar L. Mitchell
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, United States of America
| | - Ashley R. Schwarzer
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, United States of America
| | - Adélaïde Miarinjara
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, United States of America
| | - Clayton O. Jarrett
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, United States of America
| | - Angela D. Luis
- Department of Ecosystem and Conservation Sciences, University of Montana, Missoula, Montana, United States of America
| | - B. Joseph Hinnebusch
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, United States of America
- * E-mail:
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3
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Wilber MQ, Knapp RA, Smith TC, Briggs CJ. Host density has limited effects on pathogen invasion, disease-induced declines and within-host infection dynamics across a landscape of disease. J Anim Ecol 2022; 91:2451-2464. [PMID: 36285540 DOI: 10.1111/1365-2656.13823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Accepted: 09/20/2022] [Indexed: 12/14/2022]
Abstract
1. Host density is hypothesized to be a major driver of variability in the responses and outcomes of wildlife populations following pathogen invasion. While the effects of host density on pathogen transmission have been extensively studied, these studies are dominated by theoretical analyses and small-scale experiments. This focus leads to an incomplete picture regarding how host density drives observed variability in disease outcomes in the field. 2. Here, we leveraged a dataset of hundreds of replicate amphibian populations that varied by orders of magnitude in host density. We used these data to test the effects of host density on three outcomes following the arrival of the amphibian-killing fungal pathogen Batrachochytrium dendrobatidis (Bd): the probability that Bd successfully invaded a host population and led to a pathogen outbreak, the magnitude of the host population-level decline following an outbreak and within-host infection dynamics that drive population-level outcomes in amphibian-pathogen systems. 3. Based on previous small-scale transmission experiments, we expected that populations with higher densities would be more likely to experience Bd outbreaks and would suffer larger proportional declines following outbreaks. To test these predictions, we developed and fitted a Hidden Markov Model that accounted for imperfectly observed disease outbreak states in the amphibian populations we surveyed. 4. Contrary to our predictions, we found minimal effects of host density on the probability of successful Bd invasion, the magnitude of population decline following Bd invasion and the dynamics of within-host infection intensity. Environmental conditions, such as summer temperature, winter severity and the presence of pathogen reservoirs, were more predictive of variability in disease outcomes. 5. Our results highlight the limitations of extrapolating findings from small-scale transmission experiments to observed disease trajectories in the field and provide strong evidence that variability in host density does not necessarily drive variability in host population responses following pathogen arrival. In an applied context, we show that feedbacks between host density and disease will not necessarily affect the success of reintroduction efforts in amphibian-Bd systems of conservation concern.
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Affiliation(s)
- Mark Q Wilber
- Department of Forestry, Wildlife, and Fisheries, University of Tennessee Institute of Agriculture, Knoxville, Tennessee, USA
| | - Roland A Knapp
- Earth Research Institute, University of California, Santa Barbara, California, USA.,Sierra Nevada Aquatic Research Laboratory, University of California, Mammoth Lakes, California, USA
| | - Thomas C Smith
- Earth Research Institute, University of California, Santa Barbara, California, USA.,Sierra Nevada Aquatic Research Laboratory, University of California, Mammoth Lakes, California, USA
| | - Cheryl J Briggs
- Ecology, Evolution and Marine Biology, University of California, Santa Barbara, Santa Barbara, California, USA
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4
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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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5
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Mahmoudi A, Kryštufek B, Sludsky A, Schmid BV, DE Almeida AMP, Lei X, Ramasindrazana B, Bertherat E, Yeszhanov A, Stenseth NC, Mostafavi E. Plague reservoir species throughout the world. Integr Zool 2021; 16:820-833. [PMID: 33264458 DOI: 10.1111/1749-4877.12511] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Plague has been known since ancient times as a re-emerging infectious disease, causing considerable socioeconomic burden in regional hotspots. To better understand the epidemiological cycle of the causative agent of the plague, its potential occurrence, and possible future dispersion, one must carefully consider the taxonomy, distribution, and ecological requirements of reservoir-species in relation either to natural or human-driven changes (e.g. climate change or urbanization). In recent years, the depth of knowledge on species taxonomy and species composition in different landscapes has undergone a dramatic expansion, driven by modern taxonomic methods such as synthetic surveys that take into consideration morphology, genetics, and the ecological setting of captured animals to establish their species identities. Here, we consider the recent taxonomic changes of the rodent species in known plague reservoirs and detail their distribution across the world, with a particular focus on those rodents considered to be keystone host species. A complete checklist of all known plague-infectable vertebrates living in plague foci is provided as a Supporting Information table.
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Affiliation(s)
- Ahmad Mahmoudi
- Department of Biology, Faculty of Science, Urmia University, Iran
- Department of Epidemiology and Biostatistics, Research Centre for Emerging and Reemerging Infectious Diseases, Pasteur Institute of Iran, Tehran, Iran
| | | | - Alexander Sludsky
- Russian Research Anti-Plague Institute «Microbe», Saratov, Russian Federation
| | - Boris V Schmid
- Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, Oslo, Norway
| | | | - Xu Lei
- State Key Laboratory of Integrated Management on Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | | | - Eric Bertherat
- Department of Infectious Hazard Management, Health Emergencies Programme, WHO, Geneva, Switzerland
| | - Aidyn Yeszhanov
- M.Aikimbaev's National Scientific Center for Especially Dangerous Infections, Almaty, Kazakhstan
| | - Nils Chr Stenseth
- Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, Oslo, Norway
| | - Ehsan Mostafavi
- Department of Epidemiology and Biostatistics, Research Centre for Emerging and Reemerging Infectious Diseases, Pasteur Institute of Iran, Tehran, Iran
- National Reference Laboratory for Plague, Tularemia and Q fever, Research Centre for Emerging and Reemerging Infectious Diseases, Pasteur Institute of Iran, Akanlu, Kabudar Ahang, Hamadan, Iran
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6
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Gryseels S, De Bruyn L, Gyselings R, Calvignac‐Spencer S, Leendertz FH, Leirs H. Risk of human-to-wildlife transmission of SARS-CoV-2. Mamm Rev 2021; 51:272-292. [PMID: 33230363 PMCID: PMC7675675 DOI: 10.1111/mam.12225] [Citation(s) in RCA: 59] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 08/04/2020] [Indexed: 01/08/2023]
Abstract
It has been a long time since the world has experienced a pandemic with such a rapid devastating impact as the current COVID-19 pandemic. The causative agent, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is unusual in that it appears capable of infecting many different mammal species. As a significant proportion of people worldwide are infected with SARS-CoV-2 and may spread the infection unknowingly before symptoms occur or without any symptoms ever occurring, there is a non-negligible risk of humans spreading SARS-CoV-2 to wildlife, in particular to wild non-human mammals. Because of SARS-CoV-2's apparent evolutionary origins in bats and reports of humans transmitting the virus to pets and zoo animals, regulations for the prevention of human-to-animal transmission have so far focused mostly on these animal groups. We summarise recent studies and reports that show that a wide range of distantly related mammals are likely to be susceptible to SARS-CoV-2, and that susceptibility or resistance to the virus is, in general, not predictable, or only predictable to some extent, from phylogenetic proximity to known susceptible or resistant hosts. In the absence of solid evidence on the susceptibility and resistance to SARS-CoV-2 for each of the >6500 mammal species, we argue that sanitary precautions should be taken by humans interacting with any other mammal species in the wild. Preventing human-to-wildlife SARS-CoV-2 transmission is important to protect these animals (some of which are classed as threatened) from disease, but also to avoid establishment of novel SARS-CoV-2 reservoirs in wild mammals. The risk of repeated re-infection of humans from such a wildlife reservoir could severely hamper SARS-CoV-2 control efforts. Activities during which direct or indirect interaction with wild mammals may occur include wildlife research, conservation activities, forestry work, pest control, management of feral populations, ecological consultancy work, management of protected areas and natural environments, wildlife tourism and wildlife rehabilitation in animal shelters. During such activities, we recommend sanitary precautions, such as physical distancing, wearing face masks and gloves, and frequent decontamination, which are very similar to regulations currently imposed to prevent transmission among humans. We further recommend active surveillance of domestic and feral animals that could act as SARS-CoV-2 intermediate hosts between humans and wild mammals.
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Affiliation(s)
- Sophie Gryseels
- Department of Microbiology, Immunology and TransplantationRega Institute, KU LeuvenHerestraat 49Leuven3000Belgium
- Department of Ecology and Evolutionary BiologyUniversity of Arizona1041 E. Lowell St.TucsonAZ85721USA
- Department of BiologyUniversity of AntwerpUniversiteitsplein 1Antwerp2610Belgium
| | - Luc De Bruyn
- Department of BiologyUniversity of AntwerpUniversiteitsplein 1Antwerp2610Belgium
- Research Institute for Nature and Forest (INBO)Havenlaan 88Brussels1000Belgium
| | - Ralf Gyselings
- Research Institute for Nature and Forest (INBO)Havenlaan 88Brussels1000Belgium
| | | | | | - Herwig Leirs
- Department of BiologyUniversity of AntwerpUniversiteitsplein 1Antwerp2610Belgium
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7
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Cui Y, Schmid BV, Cao H, Dai X, Du Z, Ryan Easterday W, Fang H, Guo C, Huang S, Liu W, Qi Z, Song Y, Tian H, Wang M, Wu Y, Xu B, Yang C, Yang J, Yang X, Zhang Q, Jakobsen KS, Zhang Y, Stenseth NC, Yang R. Evolutionary selection of biofilm-mediated extended phenotypes in Yersinia pestis in response to a fluctuating environment. Nat Commun 2020; 11:281. [PMID: 31941912 PMCID: PMC6962365 DOI: 10.1038/s41467-019-14099-w] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2018] [Accepted: 12/04/2019] [Indexed: 12/16/2022] Open
Abstract
Yersinia pestis is transmitted from fleas to rodents when the bacterium develops an extensive biofilm in the foregut of a flea, starving it into a feeding frenzy, or, alternatively, during a brief period directly after feeding on a bacteremic host. These two transmission modes are in a trade-off regulated by the amount of biofilm produced by the bacterium. Here by investigating 446 global isolated Y. pestis genomes, including 78 newly sequenced isolates sampled over 40 years from a plague focus in China, we provide evidence for strong selection pressures on the RNA polymerase ω-subunit encoding gene rpoZ. We demonstrate that rpoZ variants have an increased rate of biofilm production in vitro, and that they evolve in the ecosystem during colder and drier periods. Our results support the notion that the bacterium is constantly adapting-through extended phenotype changes in the fleas-in response to climate-driven changes in the niche.
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Affiliation(s)
- Yujun Cui
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, China
| | - Boris V Schmid
- Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, Blindern, N-0316, Oslo, Norway
| | - Hanli Cao
- The Center for Disease Control and Prevention of Xinjiang Uygur Autonomous Region, Urumqi, 830002, China
| | - Xiang Dai
- The Center for Disease Control and Prevention of Xinjiang Uygur Autonomous Region, Urumqi, 830002, China
| | - Zongmin Du
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, China
| | - W Ryan Easterday
- Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, Blindern, N-0316, Oslo, Norway
| | - Haihong Fang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, China
| | - Chenyi Guo
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, China
| | - Shanqian Huang
- State Key Laboratory of Remote Sensing Science, College of Global Change and Earth System Science, Beijing Normal University, Beijing, 100875, China
| | - Wanbing Liu
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, China
| | - Zhizhen Qi
- Key Laboratory for Plague Prevention and Control of Qinghai Province, Qinghai Institute for Endemic Diseases Prevention and Control, Xining, 811602, China
| | - Yajun Song
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, China
| | - Huaiyu Tian
- State Key Laboratory of Remote Sensing Science, College of Global Change and Earth System Science, Beijing Normal University, Beijing, 100875, China
| | - Min Wang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, China
| | - Yarong Wu
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, China
| | - Bing Xu
- State Key Laboratory of Remote Sensing Science, College of Global Change and Earth System Science, Beijing Normal University, Beijing, 100875, China
| | - Chao Yang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, China
| | - Jing Yang
- State Key Laboratory of Remote Sensing Science, College of Global Change and Earth System Science, Beijing Normal University, Beijing, 100875, China
| | - Xianwei Yang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, China
| | - Qingwen Zhang
- Key Laboratory for Plague Prevention and Control of Qinghai Province, Qinghai Institute for Endemic Diseases Prevention and Control, Xining, 811602, China
| | - Kjetill S Jakobsen
- Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, Blindern, N-0316, Oslo, Norway.
| | - Yujiang Zhang
- The Center for Disease Control and Prevention of Xinjiang Uygur Autonomous Region, Urumqi, 830002, China.
| | - Nils Chr Stenseth
- Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, Blindern, N-0316, Oslo, Norway. .,Ministry of Education Key Laboratory for Earth System Modeling, Department of Earth System Science, Tsinghua University, Beijing, 100084, China.
| | - Ruifu Yang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, China.
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8
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Sun Z, Xu L, Schmid BV, Dean KR, Zhang Z, Xie Y, Fang X, Wang S, Liu Q, Lyu B, Wan X, Xu J, Stenseth NC, Xu B. Human plague system associated with rodent diversity and other environmental factors. ROYAL SOCIETY OPEN SCIENCE 2019; 6:190216. [PMID: 31312490 PMCID: PMC6599787 DOI: 10.1098/rsos.190216] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Accepted: 05/21/2019] [Indexed: 05/17/2023]
Abstract
Plague remains a threat to public health and is considered as a re-emerging infectious disease today. Rodents play an important role as major hosts in plague persistence and driving plague outbreaks in natural foci; however, few studies have tested the association between host diversity in ecosystems and human plague risk. Here we use zero-inflated generalized additive models to examine the association of species richness with human plague presence (where plague outbreaks could occur) and intensity (the average number of annual human cases when they occurred) in China during the Third Pandemic. We also account for transportation network density, annual precipitation levels and human population size. We found rodent species richness, particularly of rodent plague hosts, is positively associated with the presence of human plague. Further investigation shows that species richness of both wild and commensal rodent plague hosts are positively correlated with the presence, but only the latter correlated with the intensity. Our results indicated a positive relationship between rodent diversity and human plague, which may provide suggestions for the plague surveillance system.
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Affiliation(s)
- Zhe Sun
- Ministry of Education Key Laboratory for Earth System Modeling, Department of Earth System Science, Tsinghua University, Beijing 100084, People's Republic of China
- Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, N-0316 Oslo, Norway
- Joint Center for Global Change Studies, Beijing 100875, People's Republic of China
| | - Lei Xu
- Ministry of Education Key Laboratory for Earth System Modeling, Department of Earth System Science, Tsinghua University, Beijing 100084, People's Republic of China
- Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, N-0316 Oslo, Norway
- Joint Center for Global Change Studies, Beijing 100875, People's Republic of China
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Changping, Beijing 102206, People's Republic of China
| | - Boris V. Schmid
- Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, N-0316 Oslo, Norway
| | - Katharine R. Dean
- Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, N-0316 Oslo, Norway
| | - Zhibin Zhang
- State Key Laboratory of Integrated Management on Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, People's Republic of China
| | - Yan Xie
- State Key Laboratory of Integrated Management on Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, People's Republic of China
| | - Xiye Fang
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Changping, Beijing 102206, People's Republic of China
| | - Shuchun Wang
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Changping, Beijing 102206, People's Republic of China
| | - Qiyong Liu
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Changping, Beijing 102206, People's Republic of China
| | - Baolei Lyu
- Ministry of Education Key Laboratory for Earth System Modeling, Department of Earth System Science, Tsinghua University, Beijing 100084, People's Republic of China
| | - Xinru Wan
- State Key Laboratory of Integrated Management on Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, People's Republic of China
| | - Jianguo Xu
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Changping, Beijing 102206, People's Republic of China
| | - Nils Chr. Stenseth
- Ministry of Education Key Laboratory for Earth System Modeling, Department of Earth System Science, Tsinghua University, Beijing 100084, People's Republic of China
- Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, N-0316 Oslo, Norway
- Joint Center for Global Change Studies, Beijing 100875, People's Republic of China
| | - Bing Xu
- Ministry of Education Key Laboratory for Earth System Modeling, Department of Earth System Science, Tsinghua University, Beijing 100084, People's Republic of China
- Joint Center for Global Change Studies, Beijing 100875, People's Republic of China
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9
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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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10
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Surkova E, Popov S, Tchabovsky A. Rodent burrow network dynamics under human-induced landscape transformation from desert to steppe in Kalmykian rangelands. Integr Zool 2019; 14:410-420. [PMID: 30983144 DOI: 10.1111/1749-4877.12392] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Rodents play an important role in rangelands through the engineering of extensive burrow systems, which provides key habitats for many animal and plant species. We have analyzed the long-term variation in the abundance and distribution of rodent burrows in grazing ecosystems of southern Russia (Kalmykia) under the landscape change from desert to steppe caused by the drastic reduction of livestock after the collapse of the USSR in the early 1990s. We conducted burrow surveys in the "desert" (1980) and "steppe" (2017) periods on 19 3-km transects. We found considerable changes in burrow abundance and distribution, as well as evidence of desert habitat fragmentation and isolation caused by the expansion of tall-grass communities. Burrows of the open-dwelling diurnal ground squirrel (Spermophilus pygmaeus), the dominant and the keystone species during the "desert" period, almost completely disappeared from the rodent burrow network by 2017, indicating significant habitat loss. In contrast, the burrows of the folivorous social vole (Microtus socialis) which was rare in the 1980s, became abundant and ubiquitously distributed. The burrow density of the desert-dwelling psammophilous midday gerbil (Meriones meridianus) decreased, while the distances between occupied patches increased, indicating desert habitat fragmentation and loss of population connectivity. Burrows of the folivorous tamarisk gerbils (M. tamariscinus) were recorded only sporadically in both 1980 and 2017. The observed changes in the rodent burrow network, the key component of grazing ecosystems, correlate with rodent species ecology and can have long-term and important consequences for ecosystem functioning.
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Affiliation(s)
- Elena Surkova
- A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, Moscow, Russia
| | - Sergey Popov
- Department of Vertebrate Zoology, Lomonosov Moscow State University, Moscow, Russia
| | - Andrey Tchabovsky
- A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, Moscow, Russia
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11
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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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12
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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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13
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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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14
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Richgels KLD, Russell RE, Bron GM, Rocke TE. Evaluation of Yersinia pestis Transmission Pathways for Sylvatic Plague in Prairie Dog Populations in the Western U.S. ECOHEALTH 2016; 13:415-427. [PMID: 27234457 DOI: 10.1007/s10393-016-1133-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Revised: 01/21/2016] [Accepted: 04/15/2016] [Indexed: 06/05/2023]
Abstract
Sylvatic plague, caused by the bacterium Yersinia pestis, is periodically responsible for large die-offs in rodent populations that can spillover and cause human mortalities. In the western US, prairie dog populations experience nearly 100% mortality during plague outbreaks, suggesting that multiple transmission pathways combine to amplify plague dynamics. Several alternate pathways in addition to flea vectors have been proposed, such as transmission via direct contact with bodily fluids or inhalation of infectious droplets, consumption of carcasses, and environmental sources of plague bacteria, such as contaminated soil. However, evidence supporting the ability of these proposed alternate pathways to trigger large-scale epizootics remains elusive. Here we present a short review of potential plague transmission pathways and use an ordinary differential equation model to assess the contribution of each pathway to resulting plague dynamics in black-tailed prairie dogs (Cynomys ludovicianus) and their fleas (Oropsylla hirsuta). Using our model, we found little evidence to suggest that soil contamination was capable of producing plague epizootics in prairie dogs. However, in the absence of flea transmission, direct transmission, i.e., contact with bodily fluids or inhalation of infectious droplets, could produce enzootic dynamics, and transmission via contact with or consumption of carcasses could produce epizootics. This suggests that these pathways warrant further investigation.
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Affiliation(s)
- Katherine L D Richgels
- United States Geological Survey, National Wildlife Health Center, 6006, Schroeder Rd, Madison, WI, USA
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin - Madison, Madison, WI, USA
| | - Robin E Russell
- United States Geological Survey, National Wildlife Health Center, 6006, Schroeder Rd, Madison, WI, USA
| | - Gebbiena M Bron
- United States Geological Survey, National Wildlife Health Center, 6006, Schroeder Rd, Madison, WI, USA
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin - Madison, Madison, WI, USA
| | - Tonie E Rocke
- United States Geological Survey, National Wildlife Health Center, 6006, Schroeder Rd, Madison, WI, USA.
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15
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Xu L, Schmid BV, Liu J, Si X, Stenseth NC, Zhang Z. The trophic responses of two different rodent-vector-plague systems to climate change. Proc Biol Sci 2016; 282:20141846. [PMID: 25540277 DOI: 10.1098/rspb.2014.1846] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Plague, the causative agent of three devastating pandemics in history, is currently a re-emerging disease, probably due to climate change and other anthropogenic changes. Without understanding the response of plague systems to anthropogenic or climate changes in their trophic web, it is unfeasible to effectively predict years with high risks of plague outbreak, hampering our ability for effective prevention and control of the disease. Here, by using surveillance data, we apply structural equation modelling to reveal the drivers of plague prevalence in two very different rodent systems: those of the solitary Daurian ground squirrel and the social Mongolian gerbil. We show that plague prevalence in the Daurian ground squirrel is not detectably related to its trophic web, and that therefore surveillance efforts should focus on detecting plague directly in this ecosystem. On the other hand, plague in the Mongolian gerbil is strongly embedded in a complex, yet understandable trophic web of climate, vegetation, and rodent and flea densities, making the ecosystem suitable for more sophisticated low-cost surveillance practices, such as remote sensing. As for the trophic webs of the two rodent species, we find that increased vegetation is positively associated with higher temperatures and precipitation for both ecosystems. We furthermore find a positive association between vegetation and ground squirrel density, yet a negative association between vegetation and gerbil density. Our study thus shows how past surveillance records can be used to design and improve existing plague prevention and control measures, by tailoring them to individual plague foci. Such measures are indeed highly needed under present conditions with prevailing climate change.
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Affiliation(s)
- Lei Xu
- State Key Laboratory of Integrated Management on Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, People's Republic of China
| | - Boris V Schmid
- Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, Blindern, Oslo 0316, Norway
| | - Jun Liu
- Inner Mongolia Center for Endemic Disease Control and Research, Huhehot 010031, People's Republic of China
| | - Xiaoyan Si
- Inner Mongolia Center for Endemic Disease Control and Research, Huhehot 010031, People's Republic of China
| | - Nils Chr Stenseth
- Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, Blindern, Oslo 0316, Norway
| | - Zhibin Zhang
- State Key Laboratory of Integrated Management on Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, People's Republic of China
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16
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Bramanti B, Stenseth NC, Walløe L, Lei X. Plague: A Disease Which Changed the Path of Human Civilization. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 918:1-26. [PMID: 27722858 DOI: 10.1007/978-94-024-0890-4_1] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Plague caused by Yersinia pestis is a zoonotic infection, i.e., it is maintained in wildlife by animal reservoirs and on occasion spills over into human populations, causing outbreaks of different entities. Large epidemics of plague, which have had significant demographic, social, and economic consequences, have been recorded in Western European historical documents since the sixth century. Plague has remained in Europe for over 1400 years, intermittently disappearing, yet it is not clear if there were reservoirs for Y. pestis in Western Europe or if the pathogen was rather reimported on different occasions from Asian reservoirs by human agency. The latter hypothesis thus far seems to be the most plausible one, as it is sustained by both ecological and climatological evidence, helping to interpret the phylogeny of this bacterium.
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Affiliation(s)
- Barbara Bramanti
- Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, Oslo, Norway.
| | - Nils Chr Stenseth
- Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, Oslo, Norway
| | - Lars Walløe
- Department of Physiology, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Xu Lei
- Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, Oslo, Norway
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, 102206, Changping, Beijing, People's Republic of China
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17
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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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18
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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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19
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Climate-driven introduction of the Black Death and successive plague reintroductions into Europe. Proc Natl Acad Sci U S A 2015; 112:3020-5. [PMID: 25713390 DOI: 10.1073/pnas.1412887112] [Citation(s) in RCA: 99] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
The Black Death, originating in Asia, arrived in the Mediterranean harbors of Europe in 1347 CE, via the land and sea trade routes of the ancient Silk Road system. This epidemic marked the start of the second plague pandemic, which lasted in Europe until the early 19th century. This pandemic is generally understood as the consequence of a singular introduction of Yersinia pestis, after which the disease established itself in European rodents over four centuries. To locate these putative plague reservoirs, we studied the climate fluctuations that preceded regional plague epidemics, based on a dataset of 7,711 georeferenced historical plague outbreaks and 15 annually resolved tree-ring records from Europe and Asia. We provide evidence for repeated climate-driven reintroductions of the bacterium into European harbors from reservoirs in Asia, with a delay of 15 ± 1 y. Our analysis finds no support for the existence of permanent plague reservoirs in medieval Europe.
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20
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Abstract
Infection thresholds, widely used in disease epidemiology, may operate on host abundance and, if present, on vector abundance. For wildlife populations, host and vector abundances often vary greatly across years and consequently the threshold may be crossed regularly, both up- and downward. Moreover, vector and host abundances may be interdependent, which may affect the infection dynamics. Theory predicts that if the relevant abundance, or combination of abundances, is above the threshold, then the infection is able to spread; if not, it is bound to fade out. In practice, though, the observed level of infection may depend more on past than on current abundances. Here, we study the temporal dynamics of plague (Yersinia pestis infection), its vector (flea) and its host (great gerbil) in the PreBalkhash region in Kazakhstan. We describe how host and vector abundances interact over time and how this interaction drives the dynamics of the system around the infection threshold, consequently affecting the proportion of plague-infected sectors. We also explore the importance of the interplay between biological and detectability delays in generating the observed dynamics.
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Affiliation(s)
- Jonas Reijniers
- Department of Biology, University of Antwerp, Antwerp, Belgium
| | - Mike Begon
- Institute of Integrative Biology, University of Liverpool, Liverpool, UK
| | - Vladimir S Ageyev
- Kazakh Scientific Centre for Quarantine and Zoonotic Diseases, Almaty, Republic of Kazakhstan
| | - Herwig Leirs
- Department of Biology, University of Antwerp, Antwerp, Belgium
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21
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Giuggioli L, Kenkre VM. Consequences of animal interactions on their dynamics: emergence of home ranges and territoriality. MOVEMENT ECOLOGY 2014; 2:20. [PMID: 25709829 PMCID: PMC4337768 DOI: 10.1186/s40462-014-0020-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Accepted: 08/08/2014] [Indexed: 05/31/2023]
Abstract
Animal spacing has important implications for population abundance, species demography and the environment. Mechanisms underlying spatial segregation have their roots in the characteristics of the animals, their mutual interaction and their response, collective as well as individual, to environmental variables. This review describes how the combination of these factors shapes the patterns we observe and presents a practical, usable framework for the analysis of movement data in confined spaces. The basis of the framework is the theory of interacting random walks and the mathematical description of out-of-equilibrium systems. Although our focus is on modelling and interpreting animal home ranges and territories in vertebrates, we believe further studies on invertebrates may also help to answer questions and resolve unanswered puzzles that are still inaccessible to experimental investigation in vertebrate species.
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Affiliation(s)
- Luca Giuggioli
- />Bristol Centre for Complexity Sciences, Department of Engineering Mathematics and School of Biological Sciences, University of Bristol, Bristol, BS8 1UB UK
| | - V M Kenkre
- />Consortium of the Americas for Interdisciplinary Science and Department of Physics and Astronomy, University of New Mexico, Albuquerque, 87131 New Mexico USA
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22
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Potential corridors and barriers for plague spread in Central Asia. Int J Health Geogr 2013; 12:49. [PMID: 24171709 PMCID: PMC4228490 DOI: 10.1186/1476-072x-12-49] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Accepted: 10/23/2013] [Indexed: 12/02/2022] Open
Abstract
Background Plague (Yersinia pestis infection) is a vector-borne disease which caused millions of human deaths in the Middle Ages. The hosts of plague are mostly rodents, and the disease is spread by the fleas that feed on them. Currently, the disease still circulates amongst sylvatic rodent populations all over the world, including great gerbil (Rhombomys opimus) populations in Central Asia. Great gerbils are social desert rodents that live in family groups in burrows, which are visible on satellite images. In great gerbil populations an abundance threshold exists, above which plague can spread causing epizootics. The spatial distribution of the host species is thought to influence the plague dynamics, such as the direction of plague spread, however no detailed analysis exists on the possible functional or structural corridors and barriers that are present in this population and landscape. This study aims to fill that gap. Methods Three 20 by 20 km areas with known great gerbil burrow distributions were used to analyse the spatial distribution of the burrows. Object-based image analysis was used to map the landscape at several scales, and was linked to the burrow maps. A novel object-based method was developed – the mean neighbour absolute burrow density difference (MNABDD) – to identify the optimal scale and evaluate the efficacy of using landscape objects as opposed to square cells. Multiple regression using raster maps was used to identify the landscape-ecological variables that explain burrow density best. Functional corridors and barriers were mapped using burrow density thresholds. Cumulative resistance of the burrow distribution to potential disease spread was evaluated using cost distance analysis. A 46-year plague surveillance dataset was used to evaluate whether plague spread was radially symmetric. Results The burrow distribution was found to be non-random and negatively correlated with Greenness, especially in the floodplain areas. Corridors and barriers showed a mostly NWSE alignment, suggesting easier spreading along this axis. This was confirmed by the analysis of the plague data. Conclusions Plague spread had a predominantly NWSE direction, which is likely due to the NWSE alignment of corridors and barriers in the burrow distribution and the landscape. This finding may improve predictions of plague in the future and emphasizes the importance of including landscape analysis in wildlife disease studies.
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Kraft JP, Stapp P. Movements and burrow use by northern grasshopper mice as a possible mechanism of plague spread in prairie dog colonies. J Mammal 2013. [DOI: 10.1644/12-mamm-a-197.1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Wilschut LI, Addink EA, Heesterbeek JAP, Dubyanskiy VM, Davis SA, Laudisoit A, M Begon, Burdelov LA, Atshabar BB, de Jong SM. Mapping the distribution of the main host for plague in a complex landscape in Kazakhstan: An object-based approach using SPOT-5 XS, Landsat 7 ETM+, SRTM and multiple Random Forests. ACTA ACUST UNITED AC 2013; 23:81-94. [PMID: 24817838 PMCID: PMC4010295 DOI: 10.1016/j.jag.2012.11.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2012] [Accepted: 11/30/2012] [Indexed: 11/23/2022]
Abstract
Plague is a zoonotic infectious disease present in great gerbil populations in Kazakhstan. Infectious disease dynamics are influenced by the spatial distribution of the carriers (hosts) of the disease. The great gerbil, the main host in our study area, lives in burrows, which can be recognized on high resolution satellite imagery. In this study, using earth observation data at various spatial scales, we map the spatial distribution of burrows in a semi-desert landscape. The study area consists of various landscape types. To evaluate whether identification of burrows by classification is possible in these landscape types, the study area was subdivided into eight landscape units, on the basis of Landsat 7 ETM+ derived Tasselled Cap Greenness and Brightness, and SRTM derived standard deviation in elevation. In the field, 904 burrows were mapped. Using two segmented 2.5 m resolution SPOT-5 XS satellite scenes, reference object sets were created. Random Forests were built for both SPOT scenes and used to classify the images. Additionally, a stratified classification was carried out, by building separate Random Forests per landscape unit. Burrows were successfully classified in all landscape units. In the ‘steppe on floodplain’ areas, classification worked best: producer's and user's accuracy in those areas reached 88% and 100%, respectively. In the ‘floodplain’ areas with a more heterogeneous vegetation cover, classification worked least well; there, accuracies were 86 and 58% respectively. Stratified classification improved the results in all landscape units where comparison was possible (four), increasing kappa coefficients by 13, 10, 9 and 1%, respectively. In this study, an innovative stratification method using high- and medium resolution imagery was applied in order to map host distribution on a large spatial scale. The burrow maps we developed will help to detect changes in the distribution of great gerbil populations and, moreover, serve as a unique empirical data set which can be used as input for epidemiological plague models. This is an important step in understanding the dynamics of plague.
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Affiliation(s)
- L I Wilschut
- Utrecht University, Department of Physical Geography, Heidelberglaan 2, PO Box 80115, 3508 TC Utrecht, The Netherlands ; Utrecht University, Faculty of Veterinary Medicine, Yalelaan 7, 3584 CL Utrecht, The Netherlands
| | - E A Addink
- Utrecht University, Department of Physical Geography, Heidelberglaan 2, PO Box 80115, 3508 TC Utrecht, The Netherlands
| | - J A P Heesterbeek
- Utrecht University, Faculty of Veterinary Medicine, Yalelaan 7, 3584 CL Utrecht, The Netherlands
| | - V M Dubyanskiy
- Stavropol Plague Control Research Institute, Sovetskaya 13-15, Stavropol 355035, Russian Federation ; Anti-Plague Institute, M. Aikimbayev's Kazakh Science Centre for Quarantine and Zoonotic Diseases, 14 Kapalskaya Street, Almaty 050074, Kazakhstan
| | - S A Davis
- RMIT University, School of Mathematical and Geospatial Sciences, Melbourne, Victoria 3000, Australia
| | - A Laudisoit
- University of Liverpool, Institute of Integrative Biology, Crown Street, Liverpool, UK ; University of Antwerp, Department of Biology, Groenenborgerlaan 171, B-2020 Antwerpen, Belgium
| | - M Begon
- University of Liverpool, Institute of Integrative Biology, Crown Street, Liverpool, UK
| | - L A Burdelov
- Anti-Plague Institute, M. Aikimbayev's Kazakh Science Centre for Quarantine and Zoonotic Diseases, 14 Kapalskaya Street, Almaty 050074, Kazakhstan
| | - B B Atshabar
- Anti-Plague Institute, M. Aikimbayev's Kazakh Science Centre for Quarantine and Zoonotic Diseases, 14 Kapalskaya Street, Almaty 050074, Kazakhstan
| | - S M de Jong
- Utrecht University, Department of Physical Geography, Heidelberglaan 2, PO Box 80115, 3508 TC Utrecht, The Netherlands
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A simple model for the establishment of tick-borne pathogens of Ixodes scapularis: a global sensitivity analysis of R0. J Theor Biol 2013; 335:213-21. [PMID: 23850477 DOI: 10.1016/j.jtbi.2013.06.035] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Revised: 06/26/2013] [Accepted: 06/29/2013] [Indexed: 01/29/2023]
Abstract
The basic reproduction number of a pathogen, R0, determines whether a pathogen will spread (R0>1), when introduced into a fully susceptible population or fade out (R0<1), because infected hosts do not, on average, replace themselves. In this paper we develop a simple mechanistic model for the basic reproduction number for a group of tick-borne pathogens that wholly, or almost wholly, depend on horizontal transmission to and from vertebrate hosts. This group includes the causative agent of Lyme disease, Borrelia burgdorferi, and the causative agent of human babesiosis, Babesia microti, for which transmission between co-feeding ticks and vertical transmission from adult female ticks are both negligible. The model has only 19 parameters, all of which have a clear biological interpretation and can be estimated from laboratory or field data. The model takes into account the transmission efficiency from the vertebrate host as a function of the days since infection, in part because of the potential for this dynamic to interact with tick phenology, which is also included in the model. This sets the model apart from previous, similar models for R0 for tick-borne pathogens. We then define parameter ranges for the 19 parameters using estimates from the literature, as well as laboratory and field data, and perform a global sensitivity analysis of the model. This enables us to rank the importance of the parameters in terms of their contribution to the observed variation in R0. We conclude that the transmission efficiency from the vertebrate host to Ixodes scapularis ticks, the survival rate of Ixodes scapularis from fed larva to feeding nymph, and the fraction of nymphs finding a competent host, are the most influential factors for R0. This contrasts with other vector borne pathogens where it is usually the abundance of the vector or host, or the vector-to-host ratio, that determine conditions for emergence. These results are a step towards a better understanding of the geographical expansion of currently emerging horizontally transmitted tick-borne pathogens such as Babesia microti, as well as providing a firmer scientific basis for targeted use of acaricide or the application of wildlife vaccines that are currently in development.
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Schmid BV, Jesse M, Wilschut LI, Viljugrein H, Heesterbeek JAP. Local persistence and extinction of plague in a metapopulation of great gerbil burrows, Kazakhstan. Epidemics 2012; 4:211-8. [PMID: 23351373 DOI: 10.1016/j.epidem.2012.12.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2012] [Revised: 10/16/2012] [Accepted: 12/17/2012] [Indexed: 11/25/2022] Open
Abstract
Speculation on how the bacterium Yersinia pestis re-emerges after years of absence in the Prebalkhash region in Kazakhstan has been ongoing for half a century, but the mechanism is still unclear. One of the theories is that plague persists in its reservoir host (the great gerbil) in so-called hotspots, i.e. small regions in which the conditions remain favourable for plague to persist during times where the conditions in the Prebalkhash region as a whole have become unfavourable for plague persistence. In this paper we use a metapopulation model that describes the dynamics of the great gerbil. With this model we study the minimum size of an individual hotspot and the combined size of multiple hotspots in the Prebalkhash region that would be required for Y. pestis to persist through an inter-epizootic period. We show that the combined area of hotspots required for plague persistence is so large that it would be unlikely to have been missed by existing plague surveillance. This suggests that persistence of plague in that region cannot solely be explained by the existence of hotspots, and therefore other hypotheses, such as survival in multiple host species, and persistence in fleas or in the soil should be considered as well.
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Affiliation(s)
- B V Schmid
- Utrecht University, The Netherlands; Centre for Ecological and Evolutionary Synthesis, University of Oslo, Norway.
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