#Mechanism study on a #plague #outbreak driven by the construction of a large #reservoir in southwest #china (#surveillance from 2000-15) (PLoS Negl Trop Dis., abstract)

[Source: PLoS Neglected Tropical Diseases, full page: (LINK). Abstract, edited.]

OPEN ACCESS / PEER-REVIEWED / RESEARCH ARTICLE

Mechanism study on a plague outbreak driven by the construction of a large reservoir in southwest china (surveillance from 2000-2015)

Xin Wang , Xiaoyu Wei , Zhizhong Song , Mingliu Wang , Jinxiao Xi , Junrong Liang, Yun Liang, Ran Duan, Kecheng Tian, Yong Zhao, Guangpeng Tang, Lv You, Guirong Yang, [ … ], Huaiqi Jing

Published: March 3, 2017 / http://dx.doi.org/10.1371/journal.pntd.0005425 / This is an uncorrected proof.

 

Abstract

Background

Plague, a Yersinia pestis infection, is a fatal disease with tremendous transmission capacity. However, the mechanism of how the pathogen stays in a reservoir, circulates and then re-emerges is an enigma.

Methodology/Principal findings

We studied a plague outbreak caused by the construction of a large reservoir in southwest China followed 16-years’ surveillance.

Conclusions/Significance

The results show the prevalence of plague within the natural plague focus is closely related to the stability of local ecology. Before and during the decade of construction the reservoir on the Nanpan River, no confirmed plague has ever emerged. With the impoundment of reservoir and destruction of drowned farmland and vegetation, the infected rodent population previously dispersed was concentrated together in a flood-free area and turned a rest focus alive. Human plague broke out after the enzootic plague via the flea bite. With the construction completed and ecology gradually of human residential environment, animal population and type of vegetation settling down to a new balance, the natural plague foci returned to a rest period. With the rodent density decreased as some of them died, the flea density increased as the rodents lived near or in local farm houses where had more domestic animals, and human has a more concentrated population. In contrast, in the Himalayan marmot foci of the Qinghai-Tibet Plateau in the Qilian Mountains. There are few human inhabitants and the local ecology is relatively stable; plague is prevalence, showing no rest period. Thus the plague can be significantly affected by ecological shifts.

 

Author summary

Plague in China is shown to be in 12 kinds of natural foci with a large scale geographic and complex structure. Each plague focus has a unique ecological environment, specific geographic regions, landscape characteristics and specific hosts and vectors for the maintenance and transmission of Y. pestis. Once the environment alters, the amount and density of hosts and vectors change and so does the survival of Y. pestis. Consequently, a rest or slightly active foci can com alive, rapidly cause plague among animals and/or humans and then disappear for long periods of time. A plague outbreak among animals and humans caused by the construction of a large reservoir in southwest China is reported in this study. The reservoir was located on the border between Yunnan-Guizhou Plateau and the Guangxi Hills on the Nanpan River, and the reservoir was not previously believed to contain the plague.

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Citation: Wang X, Wei X, Song Z, Wang M, Xi J, Liang J, et al. (2017) Mechanism study on a plague outbreak driven by the construction of a large reservoir in southwest china (surveillance from 2000-2015). PLoS Negl Trop Dis 11(3): e0005425. doi:10.1371/journal.pntd.0005425

Editor: Joseph M. Vinetz, University of California San Diego School of Medicine, UNITED STATES

Received: September 16, 2016; Accepted: February 21, 2017; Published: March 3, 2017

Copyright: © 2017 Wang et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Data Availability: All relevant data are within the paper and its Supporting Information files.

Funding: This work was supported by the National Natural Science Foundation of China (General Project, no. 81470092) and the National Sci-Tech Key Project (2012ZX10004201, 2013ZX10004203-002). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Competing interests: The authors have declared that no competing interests exist.

Keywords: China; Plague; Yersinia Pestis; Guangxi.

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Pneumonic #Plague #Transmission, Moramanga, #Madagascar, 2015 (@CDC_EIDjournal, abstract)

[Source: US Centers for Disease Control and Prevention (CDC), Emerging Infectious Diseases Journal, full page: (LINK). Abstract, edited.]

Volume 23, Number 3—March 2017 / Dispatch

Pneumonic Plague Transmission, Moramanga, Madagascar, 2015

Beza Ramasindrazana, Voahangy Andrianaivoarimanana, Jean Marius Rakotondramanga, Dawn N. Birdsell, Maherisoa Ratsitorahina, and Minoarisoa Rajerison

Author affiliations: Institut Pasteur de Madagascar, Antananarivo, Madagascar (B. Ramasindrazana, V. Andrianaivoarimanana, J.M. Rakotondramanga, M. Rajerison); Northern Arizona University, Flagstaff, Arizona, USA (D.N. Birdsell); Ministry of Public Health, Antananarivo (M. Ratsitorahina)

 

Abstract

During a pneumonic plague outbreak in Moramanga, Madagascar, we identified 4 confirmed, 1 presumptive, and 9 suspected plague case-patients. Human-to-human transmission among close contacts was high (reproductive number 1.44) and the case fatality rate was 71%. Phylogenetic analysis showed that the Yersinia pestis isolates belonged to group q3, different from the previous outbreak.

Keywords: Plague; Yersinia Pestis; Madagascar.

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Successful #Treatment of #Human #Plague with Oral #Ciprofloxacin (@CDC_EIDjournal, abstract)

[Source: US Centers for Disease Control and Prevention  (CDC), Emerging Infectious Diseases Journal, full page: (LINK). Abstract, edited.]

Volume 23, Number 3—March 2017 / Research Letter

Successful Treatment of Human Plague with Oral Ciprofloxacin

Titus Apangu, Kevin Griffith1, Janet Abaru, Gordian Candini, Harriet Apio, Felix Okoth, Robert Okello, John Kaggwa, Sarah Acayo, Geoffrey Ezama, Brook Yockey, Christopher Sexton, Martin Schriefer, Edward Katongole Mbidde, and Paul Mead

Author affiliations: Uganda Virus Research Institute, Entebbe, Uganda (T. Apangu, J. Abaru, G. Candini, H. Apio, F. Okoth, R. Okello, J. Kaggwa, S. Acayo, G. Ezama, E.K. Mbidde); Centers for Disease Control and Prevention, Fort Collins, Colorado, USA (K. Griffith, B. Yockey, C. Sexton, M. Schriefer, P. Mead)

 

Abstract

The US Food and Drug Administration recently approved ciprofloxacin for treatment of plague (Yersina pestis infection) based on animal studies. Published evidence of efficacy in humans is sparse. We report 5 cases of culture-confirmed human plague treated successfully with oral ciprofloxacin, including 1 case of pneumonic plague.

Keywords: Yersinia Pestis; Plague; Ciprofloxacin.

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#Climatic and #evolutionary #drivers of phase shifts in the #plague #epidemics of #colonial #India (Proc Natl Acad Sci USA, abstract)

[Source: Proceedings of the National Academy of Sciences of the United States of American, full page: (LINK). Abstract, edited.]

Climatic and evolutionary drivers of phase shifts in the plague epidemics of colonial India

Joseph A. Lewnard a and Jeffrey P. Townsend b,c,d,1

Author Affiliations: a Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT 06520; b Department of Biostatistics, Yale School of Public Health, New Haven, CT 06510; c Program in Computational Biology and Bioinformatics, Yale University, New Haven, CT 06511; d Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT 06520

Edited by Alan Hastings, University of California, Davis, CA, and approved September 23, 2016 (received for review April 29, 2016)

 

Significance

Whereas pathogens are a well-known selective pressure on host immunity, few empirical examples illustrate the coupled dynamics of transmission and evolution. After the arrival of plague in colonial India, a plague-resistant rat phenotype was reported to have become prevalent in the subcontinent’s hardest hit cities. Capitalizing on archival data from these investigations, we identify the evolution of resistance in rats as a driver of observed shifts of seasonal outbreaks in concert with the flea lifecycle and its climatic determinants. Disentangling climatic and evolutionary forcing, our findings—based on century-old observations and experiments by the Indian Plague Commission—substantiate the rapid emergence of host heterogeneity and show how evolutionary responses can buffer host populations against environmentally forced disease dynamics.

 

Abstract

Immune heterogeneity in wild host populations indicates that disease-mediated selection is common in nature. However, the underlying dynamic feedbacks involving the ecology of disease transmission, evolutionary processes, and their interaction with environmental drivers have proven challenging to characterize. Plague presents an optimal system for interrogating such couplings: Yersinia pestis transmission exerts intense selective pressure driving the local persistence of disease resistance among its wildlife hosts in endemic areas. Investigations undertaken in colonial India after the introduction of plague in 1896 suggest that, only a decade after plague arrived, a heritable, plague-resistant phenotype had become prevalent among commensal rats of cities undergoing severe plague epidemics. To understand the possible evolutionary basis of these observations, we developed a mathematical model coupling environmentally forced plague dynamics with evolutionary selection of rats, capitalizing on extensive archival data from Indian Plague Commission investigations. Incorporating increased plague resistance among rats as a consequence of intense natural selection permits the model to reproduce observed changes in seasonal epidemic patterns in several cities and capture experimentally observed associations between climate and flea population dynamics in India. Our model results substantiate Victorian era claims of host evolution based on experimental observations of plague resistance and reveal the buffering effect of such evolution against environmental drivers of transmission. Our analysis shows that historical datasets can yield powerful insights into the transmission dynamics of reemerging disease agents with which we have limited contemporary experience to guide quantitative modeling and inference.

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1 To whom correspondence should be addressed. Email: Jeffrey.Townsend@Yale.edu.

Author contributions: J.A.L. and J.P.T. designed research; J.A.L. performed research; J.A.L. and J.P.T. contributed new reagents/analytic tools; J.A.L. analyzed data; and J.A.L. and J.P.T. wrote the paper.

The authors declare no conflict of interest.

This paper results from the Arthur M. Sackler Colloquium of the National Academy of Sciences, “Coupled Human and Environmental Systems,” held March 14–15, 2016, at the National Academies of Sciences in Washington, DC. The complete program and video recordings of most presentations are available on the NAS website at http://www.nasonline.org/Coupled_Human_and_Environmental_Systems.

This article is a PNAS Direct Submission.

This article contains supporting information online at http://www.pnas.org/lookup/suppl/doi:10.1073/pnas.1604985113/-/DCSupplemental.

Keywords: Plague; India.

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#Zoonoses As #Ecological #Entities: A Case #Review of #Plague (PLoS Negl Trop Dis., abstract)

[Source: PLoS Neglected Tropical Diseases, full page: (LINK). Abstract, edited.]

OPEN ACCESS / REVIEW

Zoonoses As Ecological Entities: A Case Review of Plague

Caio Graco Zeppelini , Alzira Maria Paiva de Almeida, Pedro Cordeiro-Estrela

Published: October 6, 2016 / http://dx.doi.org/10.1371/journal.pntd.0004949

 

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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Citation: Zeppelini CG, de Almeida AMP, Cordeiro-Estrela P (2016) Zoonoses As Ecological Entities: A Case Review of Plague. PLoS Negl Trop Dis 10(10): e0004949. doi:10.1371/journal.pntd.0004949

Editor: Juan Olano, UTMB, UNITED STATES

Published: October 6, 2016

Copyright: © 2016 Zeppelini et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Funding: The authors received no specific funding for this work.

Competing interests: The authors have declared that no competing interests exist.

Keywords: Research; Abstracts; Zoonoses; Plague.

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#Xenopsylla brasiliensis #Fleas in #Plague Focus #Areas, #Madagascar (@CDC_EIDjournal, extract)

[Source: US Centers for Disease Control and Prevention (CDC), Emerging Infectious Diseases Journal, full page: (LINK). Extract, edited.]

Volume 22, Number 12—December 2016 / Letter

Xenopsylla brasiliensis Fleas in Plague Focus Areas, Madagascar

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To the Editor:

Plague is a life-threatening infectious disease caused by the gram-negative bacterium Yersinia pestis (1). Y. pestis primarily infects rodents but can also cause outbreaks of plague in humans. The infection is usually transmitted within murine populations and then to humans by bites from infected fleas. The oriental rat flea, Xenopsylla cheopis, is considered the most efficient plague vector (1). Plague remains a major public health threat, causing annual epidemics, especially in Madagascar.

(…)

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Adélaïde Miarinjara, Christophe Rogier, Mireille Harimalala, Tojo R. Ramihangihajason, and Sébastien Boyer

Author affiliations: Université d’Antananarivo, Antananarivo, Madagascar (A. Miarinjara); Institut Pasteur, Antananarivo (A. Miarinjara, C. Rogier, M. Harimalala, T.R. Ramihangihajason, S. Boyer)

Suggested citation for this article: Miarinjara A, Rogier C, Harimalala M, Ramihangihajason TR, Boyer S. Xenopsylla brasiliensis fleas in plague focus areas, Madagascar. Emerg Infect Dis. 2016 Dec [date cited]. http://dx.doi.org/10.3201/eid2212.160318

DOI: 10.3201/eid2212.160318

Keywords: Research; Plague; Madagascar; Xenopsylla choepis.

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Adjunctive #Corticosteroid #Treatment Against #Yersinia pestis Improves Bacterial Clearance, #Immunopathology and Survival in the Mouse Model of Bubonic #Plague (J Infect Dis., abstract)

[Source: The Journal of Infectious Diseases, full page: (LINK). Abstract, edited.]

Adjunctive Corticosteroid Treatment Against Yersinia pestis Improves Bacterial Clearance, Immunopathology and Survival in the Mouse Model of Bubonic Plague

Y. Levy, Y. Vagima, A. Tidhar, A. Zauberman, M. Aftalion, D. Gur, I. Fogel1, T. Chitlaru, Y Flashner and E. Mamroud

Author Affiliations: Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona, Israel  – 1Surgeon General Headquarters, IDF Medical Corps, Tel Hashomer, Israel

Correspondence: Emanuelle Mamroud, Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, P.O. Box 19, Ness-Ziona, Israel, Tel: +972-8-9381523, Fax: +972-8-9381544, E-mail: emmym@iibr.gov.il

 

Abstract

Background. 

Plague is initiated by Yersinia pestis, a highly virulent bacterial pathogen. In late stages of the infection, bacteria proliferate extensively in the internal organs despite the massive infiltration of neutrophils. The ineffective inflammatory response associated with tissue damage may contribute to the low efficacy of anti-plague therapies during late stages of the infection. In the present study, we address the possibility of improving therapeutic efficacy by combining corticosteroid administration with antibody therapy in the mouse model of bubonic plague.

M&M. 

Mice were subcutaneously infected with a fully virulent Y. pestis strain and treated at progressive stages of the disease with anti-plague antibodies alone or in combination with the corticosteroid methylprednisolone.

Results. 

The addition of methylprednisolone to antibody therapy correlated with improved mouse survival, a significant decrease in the amount of neutrophils and matrix metalloproteinase-9 in the tissues and the mitigation of tissue damage. Interestingly, the combined treatment led to a decrease in the bacterial loads in infected organs.

Conclusions. 

Corticosteroids induce an unexpectedly effective anti-bacterial response apart from their anti-inflammatory properties, thereby improving treatment efficacy.

© The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

Keywords: Research; Abstracts; Yersinia Pestis; Corticosteroids; Bubonic Plague; Plague.

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