WorldWideScience

Sample records for plague

  1. Plague

    Science.gov (United States)

    ... In the Middle Ages in Europe, massive plague epidemics killed millions of people. Plague has not been eliminated. It can still be found in Africa, Asia, and South America. Today, plague is rare in the United States. ...

  2. Plague

    Science.gov (United States)

    Abbott, Rachel C.; Rocke, Tonie E.

    2012-01-01

    Plague offers readers an overview of this highly complex disease caused by the bacteria Yersinia pestis. The history of the disease, as well as information about Yersinia pestis and its transmission by fleas, is described. The section Geographic Distribution presents areas of the world and United States where plague occurs most commonly in rodents and humans. Species Susceptibility describes infection and disease rates in rodents, humans, and other animals. Disease Ecology considers the complex relationship among rodents, domestic and wild animals, and humans and explores possible routes of transmission and maintenance of the organism in the environment. The effects of climate change, the potential for Y. pestis to be used as a bioweapon, and the impact of plague on conservation of wildlife are considered in Points to Ponder. Disease Prevention and Control outlines methods of prevention and treatment including vaccination for prairie dogs and black-footed ferrets. A glossary of technical terms is included. Tonie E. Rocke, the senior author and an epizootiologist at the USGS National Wildlife Health Center (NWHC), is a prominent researcher on oral vaccination of prairie dogs to prevent plague. She is currently working to transfer her success in the laboratory to the field to control plague in prairie dogs. Rachel C. Abbott, a biologist at the NWHC, is assisting Dr. Rocke in this process and will coordinate field trials of the vaccine. Milt Friend, first director of the NWHC, wrote the foreword. Plague is intended for scholars and the general public. The material is presented in a simple, straightforward manner that serves both audiences. Numerous illustrations and tables provide easily understood summaries of key points and information.

  3. Plague Factsheet

    Science.gov (United States)

    ... areas through three techniques: Environmental management Public health education Preventive drug therapy Environmental Management Preventing epidemic plague requires the reducing or eliminating house rat populations in both urban and rural areas. Control of plague in such situations requires two ...

  4. Plague Symptoms

    Science.gov (United States)

    ... Search Form Controls Cancel Submit Search the CDC Plague Note: Javascript is disabled or is not supported ... message, please visit this page: About CDC.gov . Plague Home Ecology & Transmission Symptoms Diagnosis & Treatment Maps & Statistics ...

  5. Pneumonic Plague

    Science.gov (United States)

    ... Specific Hazards Bioterrorism A-Z Anthrax (Bacillus anthracis) Arenaviruses Treatment & Infection Control Specimen Submission & Lab Testing Education & ... hemorrhagic fevers (filoviruses [e.g., Ebola, Marburg] and arenaviruses [e.g., Lassa, Machupo]) Yersinia pestis (plague) Fact ...

  6. Plague Maps and Statistics

    Science.gov (United States)

    ... and Statistics Recommend on Facebook Tweet Share Compartir Plague in the United States Plague was first introduced ... per year in the United States: 1900-2012. Plague Worldwide Plague epidemics have occurred in Africa, Asia, ...

  7. Plague Prevention

    Science.gov (United States)

    ... your pet becomes sick, seek care from a veterinarian as soon as possible. Do not allow dogs or cats that roam free in endemic areas to sleep on your bed. Note: A plague vaccine is no longer available in the United States. ...

  8. Plague: Frequently Asked Questions

    Science.gov (United States)

    ... plague? Plague is an infectious disease that affects rodents, certain other animals, and humans. It is caused ... of plague? Fleas become infected by feeding on rodents, such as chipmunks, prairie dogs, ground squirrels, mice, ...

  9. Plague Diagnosis and Treatment

    Science.gov (United States)

    ... Search Form Controls Cancel Submit Search the CDC Plague Note: Javascript is disabled or is not supported ... message, please visit this page: About CDC.gov . Plague Home Ecology & Transmission Symptoms Diagnosis & Treatment Maps & Statistics ...

  10. Enzootic plague foci, Algeria

    Science.gov (United States)

    Malek, M.A.; Hammani, A.; Beneldjouzi, A.; Bitam, I.

    2014-01-01

    In Algeria, PCR sequencing of pla, glpD and rpoB genes found Yersinia pestis in 18/237 (8%) rodents of five species, including Apodemus sylvaticus, previously undescribed as pestiferous; and disclosed three new plague foci. Multiple spacer typing confirmed a new Orientalis variant. Rodent survey should be reinforced in this country hosting reemerging plague. PMID:25834736

  11. Viper Plague Project

    Science.gov (United States)

    2009-07-01

    a private herpetological collection infested with ticks (Kiel et al, 2006). Viper Plague presented signs and symptoms in the reptiles that were...1. Introduction The term Viper Plague was coined for a lethal disease state seen in snakes belonging to a private herpetological collection...Rattlesnake (Crotalus atrox). This was performed because this particular species of rattlesnake was present in the original herpetological collection

  12. Enzootic plague foci, Algeria

    Directory of Open Access Journals (Sweden)

    M.A. Malek

    2015-03-01

    Full Text Available In Algeria, PCR sequencing of pla, glpD and rpoB genes found Yersinia pestis in 18/237 (8% rodents of five species, including Apodemus sylvaticus, previously undescribed as pestiferous; and disclosed three new plague foci. Multiple spacer typing confirmed a new Orientalis variant. Rodent survey should be reinforced in this country hosting reemerging plague.

  13. Plague in Yosemite

    Centers for Disease Control (CDC) Podcasts

    2017-03-23

    Dr. Vicki Kramer, with the California Department of Public Health, discusses two cases of plague in Yosemite National Park.  Created: 3/23/2017 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 3/23/2017.

  14. Human plague occurrences in Africa

    DEFF Research Database (Denmark)

    Neerinckx, Simon; Bertherat, Eric; Leirs, Herwig

    2010-01-01

    Plague remains a public health concern worldwide, but particularly in Africa. Despite the long-standing history of human plague, it is difficult to get a historical and recent overview of the general situation. We searched and screened available information sources on human plague occurrences...... Africa and Madagascar. We show that public health concerns regarding the current plague situation are justified and that the disease should not be neglected, despite the sometimes questionability of the numbers of cases. We conclude that improving plague surveillance strategies is absolutely necessary...

  15. Plague: history and contemporary analysis.

    Science.gov (United States)

    Raoult, Didier; Mouffok, Nadjet; Bitam, Idir; Piarroux, Renaud; Drancourt, Michel

    2013-01-01

    Plague has caused ravaging outbreaks, including the Justinian plague and the "black death" in the Middle Ages. The causative agents of these outbreaks have been confirmed using modern molecular tests. The vector of plague during pandemics remains the subject of controversy. Nowadays, plague must be suspected in all areas where plague is endemic in rodents when patients present with adenitis or with pneumonia with a bloody expectorate. Diagnosis is more difficult in the situation of the reemergence of plague, as in Algeria for example, told by the first physician involved in that outbreak (NM). When in doubt, it is preferable to prescribe treatment with doxycycline while waiting for the test results because of the risk of fatality in individuals with plague. The typical bubo is a type of adenitis that is painful, red and nonfluctuating. The diagnosis is simple when microbiological analysis is conducted. Plague is a likely diagnosis when one sees gram-negative bacilli in lymph node aspirate or biopsy samples. Yersinia pestis grows very easily in blood cultures and is easy to identify by biochemical tests and MALDI-TOF mass spectrometry. Pneumonic plague and septicemic plague without adenitis are difficult to diagnose, and these diagnoses are often made by chance or retrospectively when cases are not part of an epidemic or related to another specific epidemiologic context. The treatment of plague must be based on gentamicin or doxycycline. Treatment with one of these antibiotics must be started as soon as plague is suspected. Analysis of past plague epidemics by using modern laboratory tools illustrated the value of epidemic buboes for the clinical diagnosis of plague; and brought new concepts regarding its transmission by human ectoparasites. Copyright © 2012 The British Infection Association. Published by Elsevier Ltd. All rights reserved.

  16. Molecular history of plague.

    Science.gov (United States)

    Drancourt, M; Raoult, D

    2016-11-01

    Plague, a deadly zoonose caused by the bacterium Yersinia pestis, has been firmly documented in 39 historical burial sites in Eurasia that date from the Bronze Age to two historical pandemics spanning the 6th to 18th centuries. Palaeomicrobiologic data, including gene and spacer sequences, whole genome sequences and protein data, confirmed that two historical pandemics swept over Europe from probable Asian sources and possible two-way-ticket journeys back from Europe to Asia. These investigations made it possible to address questions regarding the potential sources and routes of transmission by completing the standard rodent and rodent-flea transmission scheme. This suggested that plague was transmissible by human ectoparasites such as lice, and that Y. pestis was able to persist for months in the soil, which is a source of reinfection for burrowing mammals. The analyses of seven complete genome sequences from the Bronze Age indicated that Y. pestis was probably not an ectoparasite-borne pathogen in these populations. Further analyses of 14 genomes indicated that the Justinian pandemic strains may have formed a clade distinct from the one responsible for the second pandemic, spanning in Y. pestis branch 1, which also comprises the third pandemic strains. Further palaeomicrobiologic studies must tightly connect with historical and anthropologic studies to resolve questions regarding the actual sources of plague in ancient populations, alternative routes of transmission and resistance traits. Answering these questions will broaden our understanding of plague epidemiology so we may better face the actuality of this deadly infection in countries where it remains epidemic. Copyright © 2016. Published by Elsevier Ltd.

  17. Plague and climate: scales matter.

    Directory of Open Access Journals (Sweden)

    Tamara Ben-Ari

    2011-09-01

    Full Text Available Plague is enzootic in wildlife populations of small mammals in central and eastern Asia, Africa, South and North America, and has been recognized recently as a reemerging threat to humans. Its causative agent Yersinia pestis relies on wild rodent hosts and flea vectors for its maintenance in nature. Climate influences all three components (i.e., bacteria, vectors, and hosts of the plague system and is a likely factor to explain some of plague's variability from small and regional to large scales. Here, we review effects of climate variables on plague hosts and vectors from individual or population scales to studies on the whole plague system at a large scale. Upscaled versions of small-scale processes are often invoked to explain plague variability in time and space at larger scales, presumably because similar scale-independent mechanisms underlie these relationships. This linearity assumption is discussed in the light of recent research that suggests some of its limitations.

  18. Plague and climate: scales matter.

    Science.gov (United States)

    Ben-Ari, Tamara; Ben Ari, Tamara; Neerinckx, Simon; Gage, Kenneth L; Kreppel, Katharina; Laudisoit, Anne; Leirs, Herwig; Stenseth, Nils Chr

    2011-09-01

    Plague is enzootic in wildlife populations of small mammals in central and eastern Asia, Africa, South and North America, and has been recognized recently as a reemerging threat to humans. Its causative agent Yersinia pestis relies on wild rodent hosts and flea vectors for its maintenance in nature. Climate influences all three components (i.e., bacteria, vectors, and hosts) of the plague system and is a likely factor to explain some of plague's variability from small and regional to large scales. Here, we review effects of climate variables on plague hosts and vectors from individual or population scales to studies on the whole plague system at a large scale. Upscaled versions of small-scale processes are often invoked to explain plague variability in time and space at larger scales, presumably because similar scale-independent mechanisms underlie these relationships. This linearity assumption is discussed in the light of recent research that suggests some of its limitations.

  19. Plague: Clinics, Diagnosis and Treatment.

    Science.gov (United States)

    Nikiforov, Vladimir V; Gao, He; Zhou, Lei; Anisimov, Andrey

    2016-01-01

    Plague still poses a significant threat to human health and as a reemerging infection is unfamiliar to the majority of the modern medical doctors. In this chapter, the plague is described according to Dr. Nikiforov's experiences in the diagnosis and treatment of patients, and also a review of the relevant literature on this subject is provided. The main modern methods and criteria for laboratory diagnosis of plague are briefly described. The clinical presentations include the bubonic and pneumonic form, septicemia, rarely pharyngitis, and meningitis. Early diagnosis and the prompt initiation of treatment reduce the mortality rate associated with bubonic plague and septicemic plague to 5-50 %; although a delay of more than 24 h in the administration of antibiotics and antishock treatment can be fatal for plague patients. Most human cases can successfully be treated with antibiotics.

  20. Plague and Climate: Scales Matter

    Science.gov (United States)

    Ben Ari, Tamara; Neerinckx, Simon; Gage, Kenneth L.; Kreppel, Katharina; Laudisoit, Anne; Leirs, Herwig; Stenseth, Nils Chr.

    2011-01-01

    Plague is enzootic in wildlife populations of small mammals in central and eastern Asia, Africa, South and North America, and has been recognized recently as a reemerging threat to humans. Its causative agent Yersinia pestis relies on wild rodent hosts and flea vectors for its maintenance in nature. Climate influences all three components (i.e., bacteria, vectors, and hosts) of the plague system and is a likely factor to explain some of plague's variability from small and regional to large scales. Here, we review effects of climate variables on plague hosts and vectors from individual or population scales to studies on the whole plague system at a large scale. Upscaled versions of small-scale processes are often invoked to explain plague variability in time and space at larger scales, presumably because similar scale-independent mechanisms underlie these relationships. This linearity assumption is discussed in the light of recent research that suggests some of its limitations. PMID:21949648

  1. Plague in Tanzania: an overview.

    Science.gov (United States)

    Ziwa, Michael H; Matee, Mecky I; Hang'ombe, Bernard M; Lyamuya, Eligius F; Kilonzo, Bukheti S

    2013-10-01

    Human plague remains a public health concern in Tanzania despite its quiescence in most foci for years, considering the recurrence nature of the disease. Despite the long-standing history of this problem, there have not been recent reviews of the current knowledge on plague in Tanzania. This work aimed at providing a current overview of plague in Tanzania in terms of its introduction, potential reservoirs, possible causes of plague persistence and repeated outbreaks in the country. Plague is believed to have been introduced to Tanzania from the Middle East through Uganda with the first authentication in 1886. Xenopsylla brasiliensis, X. cheopis, Dinopsyllus lypusus, and Pulex irritans are among potential vectors while Lophuromys spp, Praomys delectorum, Graphiurus murinus, Lemniscomys striatus, Mastomys natalensis, and Rattus rattus may be the potential reservoirs. Plague persistence and repeated outbreaks in Tanzania are likely to be attributable to a complexity of factors including cultural, socio-economical, environmental and biological. Minimizing or preventing people's proximity to rodents is probably the most effective means of preventing plague outbreaks in humans in the future. In conclusion, much has been done on plague diagnosis in Tanzania. However, in order to achieve new insights into the features of plague epidemiology in the country, and to reorganize an effective control strategy, we recommend broader studies that will include the ecology of the pathogen, vectors and potential hosts, identifying the reservoirs, dynamics of infection and landscape ecology.

  2. Plague and the Human Flea, Tanzania

    DEFF Research Database (Denmark)

    Laudisoit, Anne; Leirs, Herwig; Makundi, Rhodes H

    2007-01-01

    Domestic fleas were collected in 12 villages in the western Usambara Mountains in Tanzania. Of these, 7 are considered villages with high plague frequency, where human plague was recorded during at least 6 of the 17 plague seasons between 1986 and 2004. In the remaining 5 villages with low plague...

  3. Plague Outbreak in Libya, 2009, Unrelated to Plague in Algeria

    Science.gov (United States)

    Cabanel, Nicolas; Leclercq, Alexandre; Chenal-Francisque, Viviane; Annajar, Badereddin; Rajerison, Minoarisoa; Bekkhoucha, Souad; Bertherat, Eric

    2013-01-01

    After 25 years of no cases of plague, this disease recurred near Tobruk, Libya, in 2009. An epidemiologic investigation identified 5 confirmed cases. We determined ribotypes, Not1 restriction profiles, and IS100 and IS1541 hybridization patterns of strains isolated during this outbreak. We also analyzed strains isolated during the 2003 plague epidemic in Algeria to determine whether there were epidemiologic links between the 2 events. Our results demonstrate unambiguously that neighboring but independent plague foci coexist in Algeria and Libya. They also indicate that these outbreaks were most likely caused by reactivation of organisms in local or regional foci believed to be dormant (Libya) or extinct (Algeria) for decades, rather than by recent importation of Yersinia pestis from distant foci. Environmental factors favorable for plague reemergence might exist in this area and lead to reactivation of organisms in other ancient foci. PMID:23347743

  4. Plague outbreak in Libya, 2009, unrelated to plague in Algeria.

    Science.gov (United States)

    Cabanel, Nicolas; Leclercq, Alexandre; Chenal-Francisque, Viviane; Annajar, Badereddin; Rajerison, Minoarisoa; Bekkhoucha, Souad; Bertherat, Eric; Carniel, Elisabeth

    2013-02-01

    After 25 years of no cases of plague, this disease recurred near Tobruk, Libya, in 2009. An epidemiologic investigation identified 5 confirmed cases. We determined ribotypes, Not1 restriction profiles, and IS100 and IS1541 hybridization patterns of strains isolated during this outbreak. We also analyzed strains isolated during the 2003 plague epidemic in Algeria to determine whether there were epidemiologic links between the 2 events. Our results demonstrate unambiguously that neighboring but independent plague foci coexist in Algeria and Libya. They also indicate that these outbreaks were most likely caused by reactivation of organisms in local or regional foci believed to be dormant (Libya) or extinct (Algeria) for decades, rather than by recent importation of Yersinia pestis from distant foci. Environmental factors favorable for plague reemergence might exist in this area and lead to reactivation of organisms in other ancient foci.

  5. The Formula of Plague Narratives

    DEFF Research Database (Denmark)

    Christensen, Jørgen Riber

    2015-01-01

    it is possible to establish a stable formula for plague narratives despite the spread over centuries and in different text types, and to explain this formula and possible variations of it. The initial and tentative hypothesis is that a formulaic narrative structure exists for accounts, both documentary...... and fictional, of epidemics. The samples include: Exodus, History of the Peloponnesian War, Samuel Pepys’ Diary, A Journal of the Plague Year, The Last Man, The Plague in Bergamo, Discipline and Punish: The Birth of the Prison, Doomsday, The Dead Zone, World War Z. An Oral History of the Zombie War, Pandemic...

  6. Plague Vaccines: Status and Future.

    Science.gov (United States)

    Sun, Wei

    2016-01-01

    Three major plague pandemics caused by the gram-negative bacterium Yersinia pestis have killed nearly 200 million people in human history. Due to its extreme virulence and the ease of its transmission, Y. pestis has been used purposefully for biowarfare in the past. Currently, plague epidemics are still breaking out sporadically in most of parts of the world, including the United States. Approximately 2000 cases of plague are reported each year to the World Health Organization. However, the potential use of the bacteria in modern times as an agent of bioterrorism and the emergence of a Y. pestis strain resistant to eight antibiotics bring out severe public health concerns. Therefore, prophylactic vaccination against this disease holds the brightest prospect for its long-term prevention. Here, we summarize the progress of the current vaccine development for counteracting plague.

  7. The Formula of Plague Narratives

    DEFF Research Database (Denmark)

    Christensen, Jørgen Riber

    2015-01-01

    The article is a narratological investigation of a selection of plague tales. The selection spans millennia and different text types, technologies and genres, from The Bible to apocalyptical films, iPhone games and testimonials from Médecins Sans Frontières. The research question is whether...... it is possible to establish a stable formula for plague narratives despite the spread over centuries and in different text types, and to explain this formula and possible variations of it. The initial and tentative hypothesis is that a formulaic narrative structure exists for accounts, both documentary...... and fictional, of epidemics. The samples include: Exodus, History of the Peloponnesian War, Samuel Pepys’ Diary, A Journal of the Plague Year, The Last Man, The Plague in Bergamo, Discipline and Punish: The Birth of the Prison, Doomsday, The Dead Zone, World War Z. An Oral History of the Zombie War, Pandemic...

  8. The Formula of Plague Narratives

    DEFF Research Database (Denmark)

    Christensen, Jørgen Riber

    2015-01-01

    The article is a narratological investigation of a selection of plague tales. The selection spans millennia and different text types, technologies and genres, from The Bible to apocalyptical films, iPhone games and testimonials from Médecins Sans Frontières. The research question is whether it is......, Plague Inc. and testimonials from Médecins Sans Frontières about the 2014-15 ebola outbreak in West Africa....

  9. Plague and the Human Flea, Tanzania

    DEFF Research Database (Denmark)

    Laudisoit, Anne; Leirs, Herwig; Makundi, Rhodes H

    2007-01-01

    Domestic fleas were collected in 12 villages in the western Usambara Mountains in Tanzania. Of these, 7 are considered villages with high plague frequency, where human plague was recorded during at least 6 of the 17 plague seasons between 1986 and 2004. In the remaining 5 villages with low plague...... frequency, plague was either rare or unrecorded. Pulex irritans, known as the human flea, was the predominant flea species (72.4%) in houses. The density of P. irritans, but not of other domestic fleas, was significantly higher in villages with a higher plague frequency or incidence. Moreover, the P....... irritans index was strongly positively correlated with plague frequency and with the logarithmically transformed plague incidence. These observations suggest that in Lushoto District human fleas may play a role in plague epidemiology. These findings are of immediate public health relevance because...

  10. [The Justinian plague (part one)].

    Science.gov (United States)

    Sabbatani, Sergio; Manfredi, Roberto; Fiorino, Sirio

    2012-06-01

    In their medical-historical review, the authors assess the evolution of bubonic plague epidemics: after breaking out in the Egyptian port of Pelusium in October 541 AD, the epidemics hit several regions in the Mediterranean basin in a succession of waves. The so-called Justinian plague took its name from the Byzantine emperor of the period, and seriously conditioned the expansionary aims of the Eastern Roman empire towards Italy (which was occupied by Goths), and Northern Africa (where the Vandals had settled), during the first decades of its spread. In the Eastern Empire the plague played a considerable role in reducing the tensions between Persians and Byzantines, especially on the Syrian and Anatolian fronts. It had a major demographic impact, reducing the possibility of recruitment to the Roman legions and leading to a significant drop in tax revenues, which were essential to sustain the state and its military machine. Finally, the plague also took its toll on economic resources (especially agriculture), indirectly leading to a vicious inflationary circle. In the space of over two centuries, plague epidemics paralyzed most trade and commercial exchanges. Furthermore, the Justinian plague, halting the consolidation of the influence of the Eastern Roman empire over some Western regions (including Italy and Northern Africa, which were ruled by Barbarians), supported the development and rise of a number of Roman-Barbarian kingdoms. It may therefore be suggested that the Justinian plague occurred at a very critical historical moment, which represents the real watershed between the Ancient World and the upcoming Middle Ages.

  11. The threatened plague.

    Science.gov (United States)

    Epstein, P

    1997-01-01

    This article discusses changes in disease patterns affecting human health that may be related to environmental and social changes in the world. The World Health Report reveals that 30 new diseases emerged in the past 20 years. Old diseases are becoming resistant to new drugs. Infectious diseases that were in decline are spreading: diphtheria, whooping cough, and measles. Illnesses such as malaria, fevers, cholera, and rodent-borne viruses are becoming more frequent. Diseases that are transmitted by animals or water are related to environmental and social changes. Degraded environments are susceptible to the appearance of opportunistic species, such as weeds, rodents, insects, and microorganisms. Stable environments support the welfare of large predators and control opportunistic species. Owls, coyotes, and snakes eat rodents that carry Lyme disease ticks and a variety of viruses, plague, and bacteria. Reptiles, birds, spiders, ladybugs, bats, and fish consume larvae and mosquitoes that cause malaria and fevers. Habitat loss and fragmentation, monocultures, excessive use of toxic chemicals, climate change, and weather instability are widespread global changes that reduce the predator population. Small wilderness habitats favor pests. Monocultures reduce genetic diversity and increase vulnerability. Excessive use of pesticides harms birds and helpful insects. A sign of a failing ecosystem is the population explosion of pests and disequilibrium. The Environmental Distress Syndrome is characterized as: 1) emerging infectious diseases, 2) loss of biodiversity, 3) increased generalist species and decreased specialist species, 4) declines in specific specialists, such as pollinators responsible for preservation of flowering plants, and 5) increased coastal algal blooms. The impacts of disease mean considerable costs to humans, agriculture, and livestock. Loss of resources is also costly.

  12. Red Plague Control Plan (RPCP)

    Science.gov (United States)

    Cooke, Robert W.

    2010-01-01

    SCOPE: Prescribes the minimum requirements for the control of cuprous / cupric oxide corrosion (a.k.a. Red Plague) of silver-coated copper wire, cable, and harness assemblies. PURPOSE: Targeted for applications where exposure to assembly processes, environmental conditions, and contamination may promote the development of cuprous / cupric oxide corrosion (a.k.a. Red Plague) in silver-coated copper wire, cable, and harness assemblies. Does not exclude any alternate or contractor-proprietary documents or processes that meet or exceed the baseline of requirements established by this document. Use of alternate or contractor-proprietary documents or processes shall require review and prior approval of the procuring NASA activity.

  13. Are Carnivores Universally Good Sentinels of Plague?

    OpenAIRE

    Brinkerhoff, R. Jory; Collinge, Sharon K.; Bai, Ying; Ray, Chris

    2009-01-01

    Sylvatic plague, caused by the bacterium Yersinia pestis, is a flea-borne disease that primarily affects rodents but has been detected in over 200 mammal species worldwide. Mammalian carnivores are routinely surveyed as sentinels of local plague activity, since they can present antibodies to Y. pestis infection but show few clinical signs. In Boulder County, Colorado, USA, plague epizootic events are episodic and occur in black-tailed prairie dogs. Enzootic hosts are unidentified as are plagu...

  14. Plague in the genomic area.

    Science.gov (United States)

    Drancourt, M

    2012-03-01

    With plague being not only a subject of interest for historians, but still a disease of public health concern in several countries, mainly in Africa, there were hopes that analyses of the Yersinia pestis genomes would put an end to this deadly epidemic pathogen. Genomics revealed that Y. pestis isolates evolved from Yersinia pseudotuberculosis in Central Asia some millennia ago, after the acquisition of two Y. pestis-specific plasmids balanced genomic reduction parallel with the expansion of insertion sequences, illustrating the modern concept that, except for the acquisition of plasmid-borne toxin-encoding genes, the increased virulence of Y. pestis resulted from gene loss rather than gene acquisition. The telluric persistence of Y. pestis reminds us of this close relationship, and matters in terms of plague epidemiology. Whereas biotype Orientalis isolates spread worldwide, the Antiqua and Medievalis isolates showed more limited expansion. In addition to animal ectoparasites, human ectoparasites such as the body louse may have participated in this expansion and in devastating historical epidemics. The recent analysis of a Black Death genome indicated that it was more closely related to the Orientalis branch than to the Medievalis branch. Modern Y. pestis isolates grossly exhibit the same gene content, but still undergo micro-evolution in geographically limited areas by differing in the genome architecture, owing to inversions near insertion sequences and the stabilization of the YpfPhi prophage in Orientalis biotype isolates. Genomics have provided several new molecular tools for the genotyping and phylogeographical tracing of isolates and description of plague foci. However, genomics and post-genomics approaches have not yet provided new tools for the prevention, diagnosis and management of plague patients and the plague epidemics still raging in some sub-Saharan countries. © 2012 The Author. Clinical Microbiology and Infection © 2012 European Society of

  15. Are carnivores universally good sentinels of plague?

    Science.gov (United States)

    Brinkerhoff, R Jory; Collinge, Sharon K; Bai, Ying; Ray, Chris

    2009-10-01

    Sylvatic plague, caused by the bacterium Yersinia pestis, is a flea-borne disease that primarily affects rodents but has been detected in over 200 mammal species worldwide. Mammalian carnivores are routinely surveyed as sentinels of local plague activity, since they can present antibodies to Y. pestis infection but show few clinical signs. In Boulder County, Colorado, USA, plague epizootic events are episodic and occur in black-tailed prairie dogs. Enzootic hosts are unidentified as are plague foci. For three years, we systematically sampled carnivores in two distinct habitat types to determine whether carnivores may play a role in maintenance or transmission of Y. pestis and to identify habitats associated with increased plague prevalence. We sampled 83 individuals representing six carnivore species and found only two that had been exposed to Y. pestis. The low overall rate of plague exposure in carnivores suggests that plague may be ephemeral in this study system, and thus we cannot draw any conclusions regarding habitat-associated plague foci or temporal changes in plague activity. Plague epizootics involving prairie dogs were confirmed in this study system during two of the three years of this study, and we therefore suggest that the targeting carnivores to survey for plague may not be appropriate in all ecological systems.

  16. Bubonic and pneumonic plague - Uganda, 2006.

    Science.gov (United States)

    2009-07-24

    Plague is a life-threatening fleaborne disease caused by the bacterium Yersinia pestis. The most common clinical form is bubonic plague, which is characterized by high fever and regional lymphadenitis. Without treatment, infection can spread from lymph nodes to the lungs, resulting in pneumonic plague and the potential for person-to-person transmission through respiratory droplets. In November 2006, the Uganda Ministry of Health received reports of an increase in bubonic plague cases and a possible outbreak of pneumonic plague among residents in the Arua and Nebbi districts. In response, the Uganda Ministry of Health and CDC conducted a joint investigation in the two districts during November 28-December 30, 2006. Overall, 127 clinical plague cases were identified, along with evidence of a focal pneumonic outbreak in Nebbi District. Median age of the patients was 14 years (range: 2 weeks-65 years); 65 (51%) were female. Twenty-eight (22%) of the 127 patients died. Among the 102 patients with documented symptoms, 90 (88%) had bubonic plague, and 12 (12%) had pneumonic plague. The results of this investigation underscore the need to 1) continue efforts to educate residents of rural Uganda regarding the source, signs, and symptoms of plague and the life-saving importance of seeking treatment; 2) strengthen plague surveillance and diagnostic capabilities; and 3) improve emergency response and vector-control capacity, especially in remote regions of the country.

  17. Research misconduct: A neglected plague.

    Science.gov (United States)

    Deshmukh, Manjiri A; Dodamani, Arun S; Khairnar, Mahesh R; Naik, Rahul G

    2017-01-01

    Truthfulness and honesty are absolute essentials of research. But to sustain in the not-so-pleasant "publish-or-perish" environment and "cut-throat" competition to increase the credibility associated with one's name, many individual researchers as well as research groups are turning towards research misconduct and this plague is gradually reaching epidemic and pandemic proportions. This overview highlights the various types and means of research misconduct and gives suggestions aiming to curb this academic menace so that research sanctity and integrity can be preserved and scientific research does not get polluted by the dirt of misreported or fabricated data.

  18. Plague

    Science.gov (United States)

    ... is a disease that affects humans and other mammals. People typically get infected after being bitten by ... Facilities Biosafety Laboratory Sites Rutgers University University of Alabama George Mason University Tufts University Tulane University Regional ...

  19. Plague dynamics are driven by climate variation

    DEFF Research Database (Denmark)

    Stenseth, Nils Chr.; Samia, Noelle I.; Viljugrein, Hildegunn

    2006-01-01

    The bacterium Yersinia pestis causes bubonic plague. In Central Asia, where human plague is still reported regularly, the bacterium is common in natural populations of great gerbils. By using field data from 1949-1995 and previously undescribed statistical techniques, we show that Y. pestis...... prevalence in gerbils increases with warmer springs and wetter summers: A 1°C increase in spring is predicted to lead to a >50% increase in prevalence. Climatic conditions favoring plague apparently existed in this region at the onset of the Black Death as well as when the most recent plague pandemic arose...... in the same region, and they are expected to  continue or become more favorable as a result of climate change.  Threats of outbreaks may thus be increasing where humans live in close contact with rodents and fleas (or other wildlife) harboring endemic plague....

  20. Vaccination against bubonic and pneumonic plague.

    Science.gov (United States)

    Titball, R W; Williamson, E D

    2001-07-20

    Yersinia pestis is the etiological agent of bubonic and pneumonic plague, diseases which have caused over 200 milllion human deaths in the past. Plague still occurs throughout the world today, though for reasons that are not fully understood pandemics of disease do not develop from these outbreaks. Antibiotic treatment of bubonic plague is usually effective, but pneumonic plague is difficult to treat and even with antibiotic therapy death often results. A killed whole cell plague vaccine has been used in the past, but recent studies in animals have shown that this vaccine offers poor protection against pneumonic disease. A live attenuated vaccine is also available. Whilst this vaccine is effective, it retains some virulence and in most countries it is not considered to be suitable for use in humans. We review here work to develop improved sub-unit and live attenuated vaccines against plague. A sub-unit vaccine based on the F1- and V-antigens is highly effective against both bubonic and pneumonic plague, when tested in animal models of disease. This vaccine has been used to explore the utility of different intranasal and oral delivery systems, based on the microencapsulation or Salmonella delivery of sub-units.

  1. [Yersinia pestis and plague - an update].

    Science.gov (United States)

    Stock, Ingo

    2014-12-01

    The plague of man is a severe, systemic bacterial infectious disease. Without antibacterial therapy, the disease is associated with a high case fatality rate, ranging from 40% (bubonic plague) to nearly 100% (septicemic and pneumonic plague). The disease is caused by Yersinia pestis, a non-motile, gram-negative, facultative anaerobic bacterium belonging to the family of Enterobacteriaceae. In nature, Y. pestis has been found in several rodent species and some other small animals such as shrews. Within its reservoir host, Y. pestis circulates via flea bites. Transmission of Y. pestis to humans occurs by the bite of rat fleas, other flea vectors or by non vectorial routes, e. g., handling infected animals or consumption of contaminated food. Human-to-human transmission of the pathogen occurs primarily through aerosol droplets. Compared to the days when plague was a pandemic scourge, the disease is now relatively rare and limited to some rural areas of Africa. During the last ten years, however, plague outbreaks have been registered repea- tedly in some African regions. For treatment of plague, streptomycin is still considered the drug of choice. Chloramphenicol, doxycycline, gentamicin and ciprofloxacin are also promising drugs. Recombinant vaccines against plague are in clinical development.

  2. A review of plague persistence with special emphasis on fleas

    Science.gov (United States)

    Wimsatt, Jeffrey; Biggins, Dean E.

    2009-01-01

    Sylvatic plague is highly prevalent during infrequent epizootics that ravage the landscape of western North America. During these periods, plague dissemination is very efficient. Epizootics end when rodent and flea populations are decimated and vectored transmission declines. A second phase (enzootic plague) ensues when plague is difficult to detect from fleas, hosts or the environment, and presents less of a threat to public health.

  3. Ecology of plague in Africa: response of indigenous wild rodents to experimental plague infection

    OpenAIRE

    Isaäcson, Margaretha; Taylor, Paul; Arntzen, Lorraine

    1983-01-01

    The Mastomys natalensis species complex, subdivided into genetically distinct species having diploid chromosome numbers 2n = 32 and 2n = 36, is a reservoir for several zoonoses including Lassa fever and plague. This report describes a study to determine whether these sibling species and three other rodent species have different potential as reservoirs for plague. It was found that M. natalensis (2n = 32) was significantly more resistant to experimental plague infection (50% survived inoculati...

  4. Sylvatic plague vaccine: combating plague in prarie dogs and black-footed ferrets

    Science.gov (United States)

    Rocke, Tonie E.; Abbott, Rachel C.

    2012-01-01

    After achieving promising results in laboratory trials, researchers at the USGS National Wildlife Health Center (NWHC) and University of Wisconsin at Madison will soon begin field testing a new oral vaccine for sylvatic plague, a devastating disease affecting prairie dogs and other mammals, particularly the endangered black-footed ferret. Our team has developed and is currently registering a sylvatic plague vaccine (SPV) that uses raccoon poxvirus (RCN) to express two key antigens of the Yersinia pestis bacterium, the causative agent of plague.

  5. Sylvatic plague vaccine: combating plague in prarie dogs and black-footed ferrets

    Science.gov (United States)

    Rocke, Tonie E.; Abbott, Rachel C.

    2012-01-01

    After achieving promising results in laboratory trials, researchers at the USGS National Wildlife Health Center (NWHC) and University of Wisconsin at Madison will soon begin field testing a new oral vaccine for sylvatic plague, a devastating disease affecting prairie dogs and other mammals, particularly the endangered black-footed ferret. Our team has developed and is currently registering a sylvatic plague vaccine (SPV) that uses raccoon poxvirus (RCN) to express two key antigens of the Yersinia pestis bacterium, the causative agent of plague.

  6. Plague metapopulation dynamics in a natural reservoir

    DEFF Research Database (Denmark)

    Davis, S; Klassovskiy, N; Ageyev, V

    2007-01-01

    The ecology of plague (Yersinia pestis infection) in its ancient foci in Central Asia remains poorly understood. We present field data from two sites in Kazakhstan where the great gerbil (Rhombomys opimus) is the major natural host. Family groups inhabit and defend burrow systems spaced throughout...... the landscape, such that the host population may be considered a metapopulation, with each occupied burrow system a subpopulation. We examine plague transmission within and between family groups and its effect on survival. Transmission of plague occurred disproportionately within family groups although not all...... gerbils became infected once plague entered a burrow system. There were no spatial patterns to suggest that family groups in close proximity to infected burrow systems were more at risk of infection than those far away. At one site, infection increased the chances of burrow-system extinction. Overall...

  7. Frequently Asked Questions (FAQ) about Plague

    Science.gov (United States)

    ... Specific Hazards Bioterrorism A-Z Anthrax (Bacillus anthracis) Arenaviruses Treatment & Infection Control Specimen Submission & Lab Testing Education & ... hemorrhagic fevers (filoviruses [e.g., Ebola, Marburg] and arenaviruses [e.g., Lassa, Machupo]) Yersinia pestis (plague) Fact ...

  8. Pneumonic Plague Outbreak, Northern Madagascar, 2011

    Science.gov (United States)

    Richard, Vincent; Herindrainy, Perlinot; Soanandrasana, Rahelinirina; Ratsitoharina, Maherisoa; Rakotomanana, Fanjasoa; Andrianalimanana, Samuel; Scholz, Holger C.; Rajerison, Minoarisoa

    2015-01-01

    Yersinia pestis, the causative agent of plague, is endemic to Madagascar, particularly to the central highlands. Although plague has not been previously reported in northern Madagascar, an outbreak of pneumonic plague occurred in this remote area in 2011. Over a 27-day period, 17 suspected, 2 presumptive, and 3 confirmed human cases were identified, and all 15 untreated 20 patients died. Molecular typing of Y. pestis isolated from 2 survivors and 5 Rattus rattus rat samples identified the Madagascar-specific 1.ORI3-k single-nucleotide polymorphism genotype and 4 clustered regularly interspaced short palindromic repeat patterns. This outbreak had a case-fatality rate of 100% for nontreated patients. The Y. pestis 1.ORI3-k single-nucleotide polymorphism genotype might cause larger epidemics. Multidrug-resistant strains and persistence of the pathogen in natural foci near human settlements pose severe risks to populations in plague-endemic regions and require outbreak response strategies. PMID:25530466

  9. Human Plague Risk: Spatial-Temporal Models

    Science.gov (United States)

    Pinzon, Jorge E.

    2010-01-01

    This chpater reviews the use of spatial-temporal models in identifying potential risks of plague outbreaks into the human population. Using earth observations by satellites remote sensing there has been a systematic analysis and mapping of the close coupling between the vectors of the disease and climate variability. The overall result is that incidence of plague is correlated to positive El Nino/Southem Oscillation (ENSO).

  10. Ecology of plague in Africa: response of indigenous wild rodents to experimental plague infection.

    Science.gov (United States)

    Isaäcson, M; Taylor, P; Arntzen, L

    1983-01-01

    The Mastomys natalensis species complex, subdivided into genetically distinct species having diploid chromosome numbers 2n = 32 and 2n = 36, is a reservoir for several zoonoses including Lassa fever and plague. This report describes a study to determine whether these sibling species and three other rodent species have different potential as reservoirs for plague. It was found that M. natalensis (2n = 32) was significantly more resistant to experimental plague infection (50% survived inoculation with 120 000 Yersinia pseudotuberculosis subsp. pestis) than was M. coucha (2n = 36) (none of which survived doses of 190 Y. pseudotuberculosis subsp.pestis). In descending order of resistance were M. natalensis, Aethomys chrysophilus, M. coucha, Tatera leucogaster and A. namaquensis. No A. namaquensis survived inoculation of 10 or more plague bacilli.Previous reports on susceptibility to plague or other infections, which were based exclusively on findings in the universally distributed laboratory-bred Mastomys, are thus not necessarily applicable to the M. natalensis species as a whole but probably only to M. coucha. The Y. pseudotuberculosis subsp. pestis fraction-1 passive haemagglutination test appeared to be relatively insensitive in that only 5 out of 47 animals surviving experimental plague infection showed specific antibodies 6 weeks after challenge.The geographic distribution of human plague in southern Africa corresponds closely with that of the plague-susceptible species, M. coucha, while the resistant species, M. natalensis, predominates in areas where human plague has not been recorded. The role of A. namaquensis in the ecology of plague needs to be carefully studied and its possible importance in plague research should be investigated further.

  11. Mountain plover responses to plague in Montana.

    Science.gov (United States)

    Dinsmore, Stephen J; Smith, Mark D

    2010-01-01

    Plague is a bacterial (Yersinia pestis) disease that causes epizootic die-offs in black-tailed prairie dog (Cynomys ludovicianus) populations in the North American Great Plains. Through their grazing and burrowing, prairie dogs modify vegetation and landscape structure on their colonies in ways that affect other grassland species. Plague epizootics on prairie dog colonies can have indirect effects on species associated with colonies. The mountain plover (Charadrius montanus) preferentially nests on black-tailed prairie dog colonies and is thus negatively impacted by the loss of prairie dogs. We studied the effects of plague and colony spatial characteristics on the occupancy of 81 prairie dog colonies by nesting plovers in Phillips County, Montana, during a 13-year period (1995-2007). We used a robust design patch occupancy model to investigate how colony occupancy and extinction and colonization rates were affected by plague history, colony size, and colony shape. Here extinction and colonization rates refer to the probability that a colony loses/gains plovers in a subsequent nesting season, given that it had/lacked plovers in that breeding season. Colony occupancy was best explained by a model with no annual variation or plague effects. Colony extinction rates were driven by a combination of a quadratic of colony area, a 3-year plague response, and a measure of colony shape. Conversely, colonization rates were best explained by a model with a 4-year plague response. The estimated annual proportion of colonies occupied by plovers was 0.75 (95% confidence interval = 0.57-0.87). Estimated extinction probability ranged from a low of 0.07 (standard error [SE] = 0.02) in 2002 to a high of 0.25 (SE = 0.03) in 1995; colonization probability ranged from 0.24 (SE = 0.05) in 2006 to 0.35 (SE = 0.05) in 2000. Our results highlight how a bird that depends on prairie dogs for nesting habitat responds to plague history and other spatial characteristics of the colony. Ultimately

  12. Burrowing Owls, Pulex irritans, and Plague.

    Science.gov (United States)

    Belthoff, James R; Bernhardt, Scott A; Ball, Christopher L; Gregg, Michael; Johnson, David H; Ketterling, Rachel; Price, Emily; Tinker, Juliette K

    2015-09-01

    Western Burrowing Owls (Athene cunicularia hypugaea) are small, ground-dwelling owls of western North America that frequent prairie dog (Cynomys spp.) towns and other grasslands. Because they rely on rodent prey and occupy burrows once or concurrently inhabited by fossorial mammals, the owls often harbor fleas. We examined the potential role of fleas found on burrowing owls in plague dynamics by evaluating prevalence of Yersinia pestis in fleas collected from burrowing owls and in owl blood. During 2012-2013, fleas and blood were collected from burrowing owls in portions of five states with endemic plague-Idaho, Oregon, Washington, Colorado, and South Dakota. Fleas were enumerated, taxonomically identified, pooled by nest, and assayed for Y. pestis using culturing and molecular (PCR) approaches. Owl blood underwent serological analysis for plague antibodies and nested PCR for detection of Y. pestis. Of more than 4750 fleas collected from owls, Pulex irritans, a known plague vector in portions of its range, comprised more than 99.4%. However, diagnostic tests for Y. pestis of flea pools (culturing and PCR) and owl blood (PCR and serology) were negative. Thus, even though fleas were prevalent on burrowing owls and the potential for a relationship with burrowing owls as a phoretic host of infected fleas exists, we found no evidence of Y. pestis in sampled fleas or in owls that harbored them. We suggest that studies similar to those reported here during plague epizootics will be especially useful for confirming these results.

  13. Plague in China 2014-All sporadic case report of pneumonic plague.

    Science.gov (United States)

    Li, Yun-Fang; Li, De-Biao; Shao, Hong-Sheng; Li, Hong-Jun; Han, Yue-Dong

    2016-02-19

    Yersinia pestis is the pathogen of the plague and caused three pandemics worldwide. Pneumonic plague is rarer than bubonic and septicemic plague. We report detailed clinical and pathogenic data for all the three sporadic cases of pneumonic plagues in China in 2014. All the three patients are herders in Gansu province of China. They were all infected by Yersinia pestis and displayed in the form of pneumonic plague respectively without related. We tested patient specimens from the upper (nasopharyngeal swabs) or the lower (sputum) respiratory tract and whole blood, plasma, and serum specimens for Yersinia pestis. All patients had fever, cough and dyspnea, and for patient 2 and 3, unconscious. Respiratory symptoms were predominant with acute respiratory failure. The chest X-ray showed signs consistent with necrotizing inflammation with multiple lobar involvements. Despite emergency treatment, all patients died of refractory multiple organ failure within 24 h after admission to hospital. All the contacts were quarantined immediately and there were no secondary cases. Nowadays, the plague is epidemic in animals and can infect people who contact with the infected animals which may cause an epidemic in human. We think dogs maybe an intermediate vector for plague and as a source of risk for humans who are exposed to pet animals or who work professionally with canines. If a patient has been exposed to a risk factor and has fever and dyspnea, plague should be considered. People who had contact with a confirmed case should be isolated and investigated for F1 antigen analysis and receive post-exposure preventive treatment. A vaccination strategy might be useful for individuals who are occupationally exposed in areas where endemically infected reservoirs of plague-infected small mammals co-exist.

  14. Modeling plague transmission in Medieval European cities

    OpenAIRE

    Dean, Katharine Rose

    2015-01-01

    The Black Death pandemic swept through Europe during the Middle Ages leading to high mortality from plague, caused by the bacterium Yersinia pestis. How the disease was transmitted in Europe is not fully elucidated, and prior to the identification of the bacterium in medieval tooth samples, the nature of the pandemic led to speculation that the Black Death was not the same disease as current-day plague. In the classical mode of transmission to humans, black rats act as an intermediate host an...

  15. Impact of the plague in Ancient Greece.

    Science.gov (United States)

    Soupios, M A

    2004-03-01

    Disease as a pivotal factor in determining the course of human events may be one og the least considered historical variables. When assessing the critical junctures of history, historians seem more inclined to focus on the impact of conquering armies, economic revolutions, and technologic breakthroughs. This analysis attempts to illustrate the seminal effects of the great plague of Athens. By depleting Athenian military personnel, depriving Athens of its charismatic leadership, and dissolving the system of ideals and principles that distinguished Athens from the rest of antiquity, the plague materially altered the outcome of the Peloponnesian War, which in turn deflected the flow of all subsequent Hellenic history.

  16. Empirical assessment of a threshold model for sylvatic plague

    DEFF Research Database (Denmark)

    Davis, Stephen; Leirs, Herwig; Viljugrein, H.

    2007-01-01

    Plague surveillance programmes established in Kazakhstan, Central Asia, during the previous century, have generated large plague archives that have been used to parameterize an abundance threshold model for sylvatic plague in great gerbil (Rhombomys opimus) populations. Here, we assess the model...

  17. Wild felids as hosts for human plague, Western United States

    Science.gov (United States)

    Bevins, S.N.; Tracey, J.A.; Franklin, S.P.; Schmit, V.L.; MacMillan, M.L.; Gage, K.L.; Schriefer, M.E.; Logan, K.A.; Sweanor, L.L.; Alldredge, M.W.; Krumm, C.; Boyce, W.M.; Vickers, W.; Riley, S.P.D.; Lyren, L.M.; Boydston, E.E.; Fisher, R.N.; Roelke, M.E.; Salman, M.; Crooks, K.R.; VandeWoude, S.

    2009-01-01

    Plague seroprevalence was estimated in populations pumas and bobcats in the western United States. High levels of exposure in plague-endemic regions indicate the need to consider the ecology and pathobiology of plague nondomestic felid hosts to better understand the role of these species in disease persistence and transmission.

  18. Saving Resources with Plagues in Genetic Algorithms

    Energy Technology Data Exchange (ETDEWEB)

    de Vega, F F; Cantu-Paz, E; Lopez, J I; Manzano, T

    2004-06-15

    The population size of genetic algorithms (GAs) affects the quality of the solutions and the time required to find them. While progress has been made in estimating the population sizes required to reach a desired solution quality for certain problems, in practice the sizing of populations is still usually performed by trial and error. These trials might lead to find a population that is large enough to reach a satisfactory solution, but there may still be opportunities to optimize the computational cost by reducing the size of the population. This paper presents a technique called plague that periodically removes a number of individuals from the population as the GA executes. Recently, the usefulness of the plague has been demonstrated for genetic programming. The objective of this paper is to extend the study of plagues to genetic algorithms. We experiment with deceptive trap functions, a tunable difficult problem for GAs, and the experiments show that plagues can save computational time while maintaining solution quality and reliability.

  19. Study on the Basic Plague Pattern of Jianchuan Plague Natural Focus, Yunnan Province, China

    Institute of Scientific and Technical Information of China (English)

    TIAN Jie

    2001-01-01

    Since the plague natural focus of Jianchuan was found in 1974, it had broken the disputation whether Yunnan has plague natural focus among Chinese and foreign scholars for long. Because the focus locates the middle part of transversal mountains with higher biological diversity and complex landscape, many problems raised at beginning in distinguishing the major hosts and vectors, modeling the structure of the focus, and resolving the contradiction between theory and excitation. In review of that, according to the principle of unified of biological structure and function, the basic plague pattern has been systematically studied on through the generalized information concept in this paper. It suggests that the focus takes the community of Apodemus chevrieri + Rattus norvegicus : Neopsylla specialis + Frontopsylla. spadix + Menopsyllus anisus + Loptopsylla segnis as maintenance subsystem, the community of E. miletus:Ctenophthalmus quadratus + Neopsylla specialis as epidematic (amplifying) subsystem, the communities of squirrel rodent-flea as alternate subsystem. The relationship between subsystems is nonlinear. No human plague case is determined by the systematicness of the plague ecosystem. The possibility of human plague will remain in systemic changing or coming into chaos. Although most researches try to analysis of plague as system by means of experiments with many quantitative criterion, these measures are difficult to comprehension the systemic essence without application of the concept of systemic theory. They are often direct, discursive and paradoxical description of appearance rather than the analysis and generalization of interaction relationship between elements, thus reversing the basic ecological concept of Y.pestis as a living thing and agent of plague.

  20. Lovastatin protects against experimental plague in mice.

    Directory of Open Access Journals (Sweden)

    Saravanan Ayyadurai

    Full Text Available BACKGROUND: Plague is an ectoparasite-borne deadly infection caused by Yersinia pestis, a bacterium classified among the group A bioterrorism agents. Thousands of deaths are reported every year in some African countries. Tetracyclines and cotrimoxazole are used in the secondary prophylaxis of plague in the case of potential exposure to Y. pestis, but cotrimoxazole-resistant isolates have been reported. There is a need for additional prophylactic measures. We aimed to study the effectiveness of lovastatin, a cholesterol-lowering drug known to alleviate the symptoms of sepsis, for plague prophylaxis in an experimental model. METHODOLOGY: Lovastatin dissolved in Endolipide was intraperitoneally administered to mice (20 mg/kg every day for 6 days prior to a Y. pestis Orientalis biotype challenge. Non-challenged, lovastatin-treated and challenged, untreated mice were also used as control groups in the study. Body weight, physical behavior and death were recorded both prior to infection and for 10 days post-infection. Samples of the blood, lungs and spleen were collected from dead mice for direct microbiological examination, histopathology and culture. The potential antibiotic effect of lovastatin was tested on blood agar plates. CONCLUSIONS/SIGNIFICANCE: Lovastatin had no in-vitro antibiotic effect against Y. pestis. The difference in the mortality between control mice (11/15; 73.5% and lovastatin-treated mice (3/15; 20% was significant (P<0.004; Mantel-Haenszel test. Dead mice exhibited Y. pestis septicemia and inflammatory destruction of lung and spleen tissues not seen in lovastatin-treated surviving mice. These data suggest that lovastatin may help prevent the deadly effects of plague. Field observations are warranted to assess the role of lovastatin in the prophylaxis of human plague.

  1. Oral vaccination against plague using Yersinia pseudotuberculosis.

    Science.gov (United States)

    Demeure, Christian E; Derbise, Anne; Carniel, Elisabeth

    2017-04-01

    Yersinia pestis, the agent of plague, is among the deadliest bacterial pathogens affecting humans, and is a potential biological weapon. Because antibiotic resistant strains of Yersinia pestis have been observed or could be engineered for evil use, vaccination against plague might become the only means to reduce mortality. Although plague is re-emerging in many countries, a vaccine with worldwide license is currently lacking. The vaccine strategy described here is based on an oral vaccination with an attenuated strain of Yersinia pseudotuberculosis. Indeed, this species is genetically almost identical to Y. pestis, but has a much lower pathogenicity and a higher genomic stability. Gradual modifications of the wild-type Yersinia pseudotuberculosis strain IP32953 were performed to generate a safe and immunogenic vaccine. Genes coding for three essential virulence factors were deleted from this strain. To increase cross-species immunogenicity, an F1-encapsulated Y. pseudotuberculosis strain was then generated. For this, the Y. pestis caf operon, which encodes F1, was inserted first on a plasmid, and subsequently into the chromosome. The successive steps achieved to reach maximal vaccine potential are described, and how each step affected bacterial virulence and the development of a protective immune response is discussed. The final version of the vaccine, named VTnF1, provides a highly efficient and long-lasting protection against both bubonic and pneumonic plague after a single oral vaccine dose. Since a Y. pestis strain deprived of F1 exist or could be engineered, we also analyzed the protection conferred by the vaccine against such strain and found that it also confers full protection against the two forms of plague. Thus, the properties of VTnF1 makes it one of the most efficient candidate vaccine for mass vaccination in tropical endemic areas as well as for populations exposed to bioterrorism. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  2. Resistance to plague among black-tailed prairie dog populations.

    Science.gov (United States)

    Rocke, Tonie E; Williamson, Judy; Cobble, Kacy R; Busch, Joseph D; Antolin, Michael F; Wagner, David M

    2012-02-01

    In some rodent species frequently exposed to plague outbreaks caused by Yersinia pestis, resistance to the disease has evolved as a population trait. As a first step in determining if plague resistance has developed in black-tailed prairie dogs (Cynomys ludovicianus), animals captured from colonies in a plague-free region (South Dakota) and two plague-endemic regions (Colorado and Texas) were challenged with Y. pestis at one of three doses (2.5, 250, or 2500 mouse LD50s). South Dakota prairie dogs were far more susceptible to plague than Colorado and Texas prairie dogs (pplague resistance.

  3. Resistance to plague among black-tailed prairie dog populations

    Science.gov (United States)

    Rocke, Tonie E.; Williamson, Judy; Cobble, Kacy R.; Busch, Joseph D.; Antolin, Michael F.; Wagner, David M.

    2012-01-01

    In some rodent species frequently exposed to plague outbreaks caused by Yersinia pestis, resistance to the disease has evolved as a population trait. As a first step in determining if plague resistance has developed in black-tailed prairie dogs (Cynomys ludovicianus), animals captured from colonies in a plague-free region (South Dakota) and two plague-endemic regions (Colorado and Texas) were challenged with Y. pestis at one of three doses (2.5, 250, or 2500 mouse LD50s). South Dakota prairie dogs were far more susceptible to plague than Colorado and Texas prairie dogs (pplague resistance.

  4. Thinking extreme social violence: the model of the literary plague.

    Science.gov (United States)

    Priel, Beatriz

    2007-12-01

    The author uses literary plagues as a model for thinking psychoanalytically about the basic anxieties activated among perpetrators of sanctioned massacres. The model of the plague allows abstracting an underlying primitive psychological organization characterized by syncretism and a powerful anxiety of de-differentiation and confusion, leading characteristically to imitative behavior within the in-group as well as to the disavowal of the out-group members similarities to oneself, i.e. the disavowal of the other's humanity. Recognizing the historical and social foundations of discrimination and genocide, the author analyzes the interaction between group and individual processes that allow ordinary people to join daily acts of immoral violence. She dramatizes the model of the plague through a psychoanalytic reading of three literary plagues: Thebes' plague according to Sophocles, Camus's chronicle of the plague in Oran, and Saramago's meditation on the plague of white blindness.

  5. Patterns of Human Plague in Uganda, 2008-2016.

    Science.gov (United States)

    Forrester, Joseph D; Apangu, Titus; Griffith, Kevin; Acayo, Sarah; Yockey, Brook; Kaggwa, John; Kugeler, Kiersten J; Schriefer, Martin; Sexton, Christopher; Ben Beard, C; Candini, Gordian; Abaru, Janet; Candia, Bosco; Okoth, Jimmy Felix; Apio, Harriet; Nolex, Lawrence; Ezama, Geoffrey; Okello, Robert; Atiku, Linda; Mpanga, Joseph; Mead, Paul S

    2017-09-01

    Plague is a highly virulent fleaborne zoonosis that occurs throughout many parts of the world; most suspected human cases are reported from resource-poor settings in sub-Saharan Africa. During 2008-2016, a combination of active surveillance and laboratory testing in the plague-endemic West Nile region of Uganda yielded 255 suspected human plague cases; approximately one third were laboratory confirmed by bacterial culture or serology. Although the mortality rate was 7% among suspected cases, it was 26% among persons with laboratory-confirmed plague. Reports of an unusual number of dead rats in a patient's village around the time of illness onset was significantly associated with laboratory confirmation of plague. This descriptive summary of human plague in Uganda highlights the episodic nature of the disease, as well as the potential that, even in endemic areas, illnesses of other etiologies might be being mistaken for plague.

  6. Pneumonic Plague: The Darker Side of Yersinia pestis.

    Science.gov (United States)

    Pechous, Roger D; Sivaraman, Vijay; Stasulli, Nikolas M; Goldman, William E

    2016-03-01

    Inhalation of the bacterium Yersinia pestis results in primary pneumonic plague. Pneumonic plague is the most severe manifestation of plague, with mortality rates approaching 100% in the absence of treatment. Its rapid disease progression, lethality, and ability to be transmitted via aerosol have compounded fears of the intentional release of Y. pestis as a biological weapon. Importantly, recent epidemics of plague have highlighted a significant role for pneumonic plague during outbreaks of Y. pestis infections. In this review we describe the characteristics of pneumonic plague, focusing on its disease progression and pathogenesis. The rapid time-course, severity, and difficulty of treating pneumonic plague highlight how differences in the route of disease transmission can enhance the lethality of an already deadly pathogen. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. [Study on the spatial and temporal distribution of animal plague in Junggar Basin plague focus].

    Science.gov (United States)

    Guo, Rong; Dai, Xiang; Cao, Hanli; Xia, Lianxu; Abuli, Miti; Abuli, Kemu; Wang, Xinhui; Aza, Ti; Jiang, Wei; Li, Bing; Zhang, Xiaobing; Lei, Gang; Wang, Qiguo; Luo, Tao; Meng, Weiwei; Buren, Mingde; Re, Na; Chen, Yan; Zhang, Yujiang

    2014-02-01

    To explore the spatial and temporal distributions of animal plague in Junggar Basin natural plague focus. Data regarding plague antibody (F1) in serum of Great Gerbil (Rhombomys opimus, R. opimus) which were collected from 2005 to 2012 in Junggar Basin and analyzed. The changing rates on the positivity of F1 that appeared spatially and temporally were also analyzed. A total of 4 825 R. opimus serum samples were collected in 13 administrative regions in Junggar Basin. showed that plague R. opimus existed in two areas-Gurbantonggut desert in the eastern-center and the clay desert of western Junggar Basin. However, in these two areas, the intensity of animal plague prevalence was different. In the former region where Yesinia pestis positive serum was detected from R. opimus, the detected rate of R. opimus was 8.39%. However, in the latter areas, the average positive rate was 1.56%. The changing trends of R. opimus plague prevalence were also varied annually. In the western Junggar Basin, the trend showed a slowly downward profile. The serum positive rate of R. opimus for Yesinia pestis decreased, from 7.59% in 2005 to 0.61% in 2008, and appeared as a resting state that none of the positive sample could be found since then. However, in the eastern-center Junggar Basin area-also named as Gurbantonggut desert which had been divided into 3 segments(western, central and eastern, according to related geographical characteristics), the changing trends of animal plague seemed quite complex. In the western segment, the animal plague had two epidemic peaks-in 2006 and 2010, with the interval of 4 years, with the higher peak of all the three geographic segments as 45.65% in 2010 and the positive serum of R. opimus for plague could be detected each year from 2006 to 2012. However, there were 3 epidemic peaks in the same period in the central and eastern segments. In the central segment, the peaks appeared in 2006, 2009 and 2011, with the intervals as 2.5 years and the average

  8. Range-wide determinants of plague distribution in North America.

    Science.gov (United States)

    Maher, Sean P; Ellis, Christine; Gage, Kenneth L; Enscore, Russell E; Peterson, A Townsend

    2010-10-01

    Plague, caused by the bacterium Yersinia pestis, is established across western North America, and yet little is known of what determines the broad-scale dimensions of its overall range. We tested whether its North American distribution represents a composite of individual host-plague associations (the "Host Niche Hypothesis"), or whether mammal hosts become infected only at sites overlapping ecological conditions appropriate for plague transmission and maintenance (the "Plague Niche Hypothesis"). We took advantage of a novel data set summarizing plague records in wild mammals newly digitized from paper-based records at the Centers for Disease Control and Prevention to develop range-wide tests of ecological niche similarity between mammal host niches and plague-infected host niches. Results indicate that plague infections occur under circumstances distinct from the broader ecological distribution of hosts, and that plague-infected niches are similar among hosts; hence, evidence coincides with the predictions of the Plague Niche Hypothesis, and contrasts with those of the Host Niche Hypothesis. The "plague niche" is likely driven by ecological requirements of vector flea species.

  9. Range-wide Determinants of Plague Distribution in North America

    Science.gov (United States)

    Maher, Sean P.; Ellis, Christine; Gage, Kenneth L.; Enscore, Russell E.; Peterson, A. Townsend

    2010-01-01

    Plague, caused by the bacterium Yersinia pestis, is established across western North America, and yet little is known of what determines the broad-scale dimensions of its overall range. We tested whether its North American distribution represents a composite of individual host–plague associations (the “Host Niche Hypothesis”), or whether mammal hosts become infected only at sites overlapping ecological conditions appropriate for plague transmission and maintenance (the “Plague Niche Hypothesis”). We took advantage of a novel data set summarizing plague records in wild mammals newly digitized from paper-based records at the Centers for Disease Control and Prevention to develop range-wide tests of ecological niche similarity between mammal host niches and plague-infected host niches. Results indicate that plague infections occur under circumstances distinct from the broader ecological distribution of hosts, and that plague-infected niches are similar among hosts; hence, evidence coincides with the predictions of the Plague Niche Hypothesis, and contrasts with those of the Host Niche Hypothesis. The “plague niche” is likely driven by ecological requirements of vector flea species. PMID:20889857

  10. Mapping risk of plague in Qinghai-Tibetan Plateau, China.

    Science.gov (United States)

    Qian, Quan; Zhao, Jian; Fang, Liqun; Zhou, Hang; Zhang, Wenyi; Wei, Lan; Yang, Hong; Yin, Wenwu; Cao, Wuchun; Li, Qun

    2014-07-10

    Qinghai-Tibetan Plateau of China is known to be the plague endemic region where marmot (Marmota himalayana) is the primary host. Human plague cases are relatively low incidence but high mortality, which presents unique surveillance and public health challenges, because early detection through surveillance may not always be feasible and infrequent clinical cases may be misdiagnosed. Based on plague surveillance data and environmental variables, Maxent was applied to model the presence probability of plague host. 75% occurrence points were randomly selected for training model, and the rest 25% points were used for model test and validation. Maxent model performance was measured as test gain and test AUC. The optimal probability cut-off value was chosen by maximizing training sensitivity and specificity simultaneously. We used field surveillance data in an ecological niche modeling (ENM) framework to depict spatial distribution of natural foci of plague in Qinghai-Tibetan Plateau. Most human-inhabited areas at risk of exposure to enzootic plague are distributed in the east and south of the Plateau. Elevation, temperature of land surface and normalized difference vegetation index play a large part in determining the distribution of the enzootic plague. This study provided a more detailed view of spatial pattern of enzootic plague and human-inhabited areas at risk of plague. The maps could help public health authorities decide where to perform plague surveillance and take preventive measures in Qinghai-Tibetan Plateau.

  11. Flea diversity as an element for persistence of plague bacteria in an East African plague focus.

    Directory of Open Access Journals (Sweden)

    Rebecca J Eisen

    Full Text Available Plague is a flea-borne rodent-associated zoonotic disease that is caused by Yersinia pestis and characterized by long quiescent periods punctuated by rapidly spreading epidemics and epizootics. How plague bacteria persist during inter-epizootic periods is poorly understood, yet is important for predicting when and where epizootics are likely to occur and for designing interventions aimed at local elimination of the pathogen. Existing hypotheses of how Y. pestis is maintained within plague foci typically center on host abundance or diversity, but little attention has been paid to the importance of flea diversity in enzootic maintenance. Our study compares host and flea abundance and diversity along an elevation gradient that spans from low elevation sites outside of a plague focus in the West Nile region of Uganda (~725-1160 m to higher elevation sites within the focus (~1380-1630 m. Based on a year of sampling, we showed that host abundance and diversity, as well as total flea abundance on hosts was similar between sites inside compared with outside the plague focus. By contrast, flea diversity was significantly higher inside the focus than outside. Our study highlights the importance of considering flea diversity in models of Y. pestis persistence.

  12. [Human plague and pneumonic plague : pathogenicity, epidemiology, clinical presentations and therapy].

    Science.gov (United States)

    Riehm, Julia M; Löscher, Thomas

    2015-07-01

    Yersinia pestis is a highly pathogenic gram-negative bacterium and the causative agent of human plague. In the last 1500 years and during three dreaded pandemics, millions of people became victims of Justinian's plague, the Black Death, or modern plague. Today, Y. pestis is endemic in natural foci of Asian, African and American countries. Due to its broad dissemination in mammal species and fleas, eradication of the pathogen will not be possible in the near future. In fact, plague is currently classified as a "re-emerging disease". Infection may occur after the bite of an infected flea, but also after oral ingestion or inhalation of the pathogen. The clinical presentations comprise the bubonic and pneumonic form, septicemia, rarely pharyngitis, and meningitis. Most human cases can successfully be treated with antibiotics. However, the high transmission rate and lethality of pneumonic plague require international and mandatory case notification and quarantine of patients. Rapid diagnosis, therapy and barrier nursing are not only crucial for the individual patient but also for the prevention of further spread of the pathogen or of epidemics. Therefore, WHO emergency schedules demand the isolation of cases, identification and surveillance of contacts as well as control of zoonotic reservoir animals and vectors. These sanctions and effective antibiotic treatment usually allow a rapid containment of outbreaks. However, multiple antibiotic resistant strains of Y. pestis have been isolated from patients in the past. So far, no outbreaks with such strains have been reported.

  13. Field efficacy trials with sylvatic plague vaccine

    Science.gov (United States)

    Richgels, Katherine; Russell, Robin E.; Rocke, Tonie E.

    2017-01-01

    These data were collected as part of a field trial to test the efficacy of a sylvatic plague vaccine. Treatment and control sites were selected randomly from the available sites at each location. Site pairs were a minimum of 20 acres, (with a few exceptions). Prairie dog trapping took place a minimum of two weeks post-baiting and trapping procedures were approved by the NWHC Animal Care and Use Committee as well as individual states as required.

  14. War, plague and exploitation in DR Congo

    Directory of Open Access Journals (Sweden)

    Dimčevska Antoaneta K.

    2007-01-01

    Full Text Available Late in autumn 2006 one of the headlines in world media was the first democratic elections in DR Congo. They took place after 30 years of Mobutu Sese Seko’s dictatorship and bloody civil wars in the period 1996-2002. These conflicts, which took approximately 4 million human lives, are called "The First African World War". Elections were held but they did not guarantee the end of trouble for the divided and tormented people in the northeast of Congo, the real scene of bloodshed. The area is still turbulent because it abounds in mineral wealth - gold, diamonds and raw materials for nuclear technology. For a whole decade, unscrupulous actors of the African crisis were fighting there, for illegal profits (achievable in the chaos of bloodshed rather than for democracy, defense of tribal interests, security, etc. as they claimed. In the mines of Eastern Congo unprecedented exploitation of people is still going on, especially of children, victims of conflicts, who suffer in great numbers from violence, starvation and diseases. These slaves of the crisis make local "warlords" and their mentors rich. The looting of the mines has stabilized the crisis because it makes possible enormous accumulation of wealth among armed decision-makers - which also includes availability of countless slaves-miners who have lost everything except their bare lives. Eastern Congo is, however, one of world’s three old focuses of plague; wild exploitation of ores in the area of this endemic disease has activated a sleepy focus and added pneumonic plague to the burdens suffered by the population of the rich but ill-fated region. This was to be expected because endemic plague in the gold-bearing evil circumstances impedes safe mining - and this will be the crucial challenge in the future of Congo. This article is an anthropological outline of the area where gold, plague, weapons and incomparable suffering of people merge together just because of cynic greed producing abuse

  15. Ecology and Geography of Plague Transmission Areas in Northeastern Brazil

    Science.gov (United States)

    Giles, John; Peterson, A. Townsend; Almeida, Alzira

    2011-01-01

    Plague in Brazil is poorly known and now rarely seen, so studies of its ecology are difficult. We used ecological niche models of historical (1966-present) records of human plague cases across northeastern Brazil to assess hypotheses regarding environmental correlates of plague occurrences across the region. Results indicate that the apparently focal distribution of plague in northeastern Brazil is indeed discontinuous, and that the causes of the discontinuity are not necessarily only related to elevation—rather, a diversity of environmental dimensions correlate to presence of plague foci in the region. Perhaps most interesting is that suitable areas for plague show marked seasonal variation in photosynthetic mass, with peaks in April and May, suggesting links to particular land cover types. Next steps in this line of research will require more detailed and specific examination of reservoir ecology and natural history. PMID:21245925

  16. [Human factors caused the third plague epidemic in Harbin].

    Science.gov (United States)

    Jin, Dong-Ying; Li, Zhi-Ping

    2011-03-01

    The third plague epidemic in Harbin broke out in 1946 and ended in 1954. Different from the first two plague epidemics (imported), the third prevalence was both imported and idiopathic infectious disease which was caused by human factors. Japanese troops set forbidden zones to build a biological weapon center, which destroyed the natural environment and offered a good growth condition for Citellus Undulatus. In 1945, on the eve of surrender, the Japanese blew up the Unit 731 germ factory located in a bungalow district, which caused diffusion of infected plague fleas. Mice of the district were infected and a man-made plague focus was created. During the prevalence of the third plague, prevention departments at all levels took a series of actions and with people's efforts, the plague was effectively controlled.

  17. Disease limits populations: plague and black-tailed prairie dogs.

    Science.gov (United States)

    Cully, Jack F; Johnson, Tammi L; Collinge, Sharon K; Ray, Chris

    2010-01-01

    Plague is an exotic vector-borne disease caused by the bacterium Yersinia pestis that causes mortality rates approaching 100% in black-tailed prairie dogs (Cynomys ludovicianus). We mapped the perimeter of the active portions of black-tailed prairie dog colonies annually between 1999 and 2005 at four prairie dog colony complexes in areas with a history of plague, as well as at two complexes that were located outside the distribution of plague at the time of mapping and had therefore never been affected by the disease. We hypothesized that the presence of plague would significantly reduce overall black-tailed prairie dog colony area, reduce the sizes of colonies on these landscapes, and increase nearest-neighbor distances between colonies. Within the region historically affected by plague, individual colonies were smaller, nearest-neighbor distances were greater, and the proportion of potential habitat occupied by active prairie dog colonies was smaller than at plague-free sites. Populations that endured plague were composed of fewer large colonies (>100 ha) than populations that were historically plague free. We suggest that these differences among sites in colony size and isolation may slow recolonization after extirpation. At the same time, greater intercolony distances may also reduce intercolony transmission of pathogens. Reduced transmission among smaller and more distant colonies may ultimately enhance long-term prairie dog population persistence in areas where plague is present.

  18. Disease limits populations: plague and black-tailed prairie dogs

    Science.gov (United States)

    Cully, Jack F.; Johnson, T.; Collinge, S.K.; Ray, C.

    2010-01-01

    Plague is an exotic vector-borne disease caused by the bacterium Yersinia pestis that causes mortality rates approaching 100% in black-tailed prairie dogs (Cynomys ludovicianus). We mapped the perimeter of the active portions of black-tailed prairie dog colonies annually between 1999 and 2005 at four prairie dog colony complexes in areas with a history of plague, as well as at two complexes that were located outside the distribution of plague at the time of mapping and had therefore never been affected by the disease. We hypothesized that the presence of plague would significantly reduce overall black-tailed prairie dog colony area, reduce the sizes of colonies on these landscapes, and increase nearest-neighbor distances between colonies. Within the region historically affected by plague, individual colonies were smaller, nearest-neighbor distances were greater, and the proportion of potential habitat occupied by active prairie dog colonies was smaller than at plague-free sites. Populations that endured plague were composed of fewer large colonies (>100 ha) than populations that were historically plague free. We suggest that these differences among sites in colony size and isolation may slow recolonization after extirpation. At the same time, greater intercolony distances may also reduce intercolony transmission of pathogens. Reduced transmission among smaller and more distant colonies may ultimately enhance long-term prairie dog population persistence in areas where plague is present.

  19. Ecology of Yersinia pestis and the Epidemiology of Plague.

    Science.gov (United States)

    Dubyanskiy, Vladimir M; Yeszhanov, Aidyn B

    2016-01-01

    This chapter summarizes information about the natural foci of plague in the world. We describe the location, main hosts, and vectors of Yersinia pestis. The ecological features of the hosts and vectors of plague are listed, including predators - birds and mammals and their role in the epizootic. The epizootic process in plague and the factors affecting the dynamics of epizootic activity of natural foci of Y. pestis are described in detail. The mathematical models of the epizootic process in plague and predictive models are briefly described. The most comprehensive list of the hosts and vectors of Y. pestis in the world is presented as well.

  20. Human Anti-Plague Monoclonal Antibodies Protect Mice from Yersinia pestis in a Bubonic Plague Model

    Science.gov (United States)

    2010-10-01

    risk. PLoS ONE 2: e309. 8. Heath DG, Anderson GW, Mauro JM, Welkos SL, Andrews GP, et al. (1998) Protection against experimental bubonic and pneumonic...Pasteurella pestis in mononuclear phagocytes in the pathogenesis of flea -borne plague. J Immunol 83: 348–363. 23. Du Y, Rosqvist, Forsberg A (2002

  1. Was Plague an Exclusively Urban Phenomenon? Plague Mortality in the Seventeenth-Century Low Countries

    NARCIS (Netherlands)

    Curtis, D.R.

    2016-01-01

    Current scholarship reinforces the notion that by the early modern period, plague had become largely an urban concern in northwestern Europe. However, a data set comprised of burial information from the seventeenth-century Low Countries suggests that plague’s impact on the countryside was far more s

  2. Susceptibility to Yersinia pestis experimental infection in wild Rattus rattus, reservoir of plague in Madagascar

    OpenAIRE

    Tollenaere, C., Pernechele, B., Mäkinen, H., Parratt, S., Nemeth, M., Kovacs, G., Levente, K. Tack, A.; Rahalison, L.; Ranjalahy, M.; Duplantier, Jean-Marc; Rahelinirina, S.; Telfer, S.; Brouat, Carine

    2010-01-01

    In Madagascar, the black rat, Rattus rattus, is the main reservoir of plague (Yersinia pestis infection), a disease still responsible for hundreds of cases each year in this country. This study used experimental plague challenge to assess susceptibility in wild-caught rats to better understand how R. rattus can act as a plague reservoir. An important difference in plague resistance between rat populations from the plague focus (central highlands) and those from the plague-free zone (low altit...

  3. [Monitoring the Microtus fuscus plague epidemic in Sichuan province during 2000 - 2008.

    DEFF Research Database (Denmark)

    Wang, Li-Mao; Song, Xiao-Yu; Zhu, Xiao-Ping

    2009-01-01

    OBJECTIVE: To analyze the epidemic tendency of Microtus fuscus plague during 2000 - 2008 in Sichuan province. METHODS: To investigate the plague each year according to "overall Plan of the Plague in the Whole Nation" and "Surveillance Program of Sichuan Province Plague". RESULTS: There were plague...... of fleas, Callopsylla sparsilis, Amphipsylla tutua tutua and Rhadinopsylla dahurica vicina, with the overall infection rate as 0.054%. CONCLUSION: Plague among Microtus fuscus showed a continuous epidemic in Sichuan province during 2000 - 2008....

  4. A Deadly Path: Bacterial Spread During Bubonic Plague.

    Science.gov (United States)

    Gonzalez, Rodrigo J; Miller, Virginia L

    2016-04-01

    Yersinia pestis causes bubonic plague, a fulminant disease where host immune responses are abrogated. Recently developed in vivo models of plague have resulted in new ideas regarding bacterial spread in the body. Deciphering bacterial spread is key to understanding Y. pestis and the immune responses it encounters during infection. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Nathaniel Hodges (1629-1688): Plague doctor.

    Science.gov (United States)

    Duffin, Christopher J

    2016-02-01

    Nathaniel Hodges was the son of Thomas Hodges (1605-1672), an influential Anglican preacher and reformer with strong connections in the political life of Carolingian London. Educated at Westminster School, Trinity College Cambridge and Christ Church College, Oxford, Nathaniel established himself as a physician in Walbrook Ward in the City of London. Prominent as one of a handful of medical men who remained in London during the time of the Great Plague of 1665, he wrote the definitive work on the outbreak. His daily precautions against contracting the disease included fortifying himself with Théodore de Mayerne's antipestilential electuary and the liberal consumption of Sack. Hodges' approach to the treatment of plague victims was empathetic and based on the traditional Galenic method rather than Paracelsianism although he was pragmatic in the rejection of formulae and simples which he judged from experience to be ineffective. Besieged by financial problems in later life, his practice began to fail in the 1680s and he eventually died in a debtor's prison. © The Author(s) 2014.

  6. Hereditary Hemochromatosis Restores the Virulence of Plague Vaccine Strains

    Science.gov (United States)

    Quenee, Lauriane E.; Hermanas, Timothy M.; Ciletti, Nancy; Louvel, Helene; Miller, Nathan C.; Elli, Derek; Blaylock, Bill; Mitchell, Anthony; Schroeder, Jay; Krausz, Thomas; Kanabrocki, Joseph; Schneewind, Olaf

    2012-01-01

    Nonpigmented Yersinia pestis (pgm) strains are defective in scavenging host iron and have been used in live-attenuated vaccines to combat plague epidemics. Recently, a Y. pestis pgm strain was isolated from a researcher with hereditary hemochromatosis who died from laboratory-acquired plague. We used hemojuvelin-knockout (Hjv−/−) mice to examine whether iron-storage disease restores the virulence defects of nonpigmented Y. pestis. Unlike wild-type mice, Hjv−/− mice developed lethal plague when challenged with Y. pestis pgm strains. Immunization of Hjv−/− mice with a subunit vaccine that blocks Y. pestis type III secretion generated protection against plague. Thus, individuals with hereditary hemochromatosis may be protected with subunit vaccines but should not be exposed to live-attenuated plague vaccines. PMID:22896664

  7. Where does human plague still persist in Latin America?

    Directory of Open Access Journals (Sweden)

    Maria Cristina Schneider

    2014-02-01

    Full Text Available BACKGROUND: Plague is an epidemic-prone disease with a potential impact on public health, international trade, and tourism. It may emerge and re-emerge after decades of epidemiological silence. Today, in Latin America, human cases and foci are present in Bolivia, Brazil, Ecuador, and Peru. AIMS: The objective of this study is to identify where cases of human plague still persist in Latin America and map areas that may be at risk for emergence or re-emergence. This analysis will provide evidence-based information for countries to prioritize areas for intervention. METHODS: Evidence of the presence of plague was demonstrated using existing official information from WHO, PAHO, and Ministries of Health. A geo-referenced database was created to map the historical presence of plague by country between the first registered case in 1899 and 2012. Areas where plague still persists were mapped at the second level of the political/administrative divisions (counties. Selected demographic, socioeconomic, and environmental variables were described. RESULTS: Plague was found to be present for one or more years in 14 out of 25 countries in Latin America (1899-2012. Foci persisted in six countries, two of which have no report of current cases. There is evidence that human cases of plague still persist in 18 counties. Demographic and poverty patterns were observed in 11/18 counties. Four types of biomes are most commonly found. 12/18 have an average altitude higher than 1,300 meters above sea level. DISCUSSION: Even though human plague cases are very localized, the risk is present, and unexpected outbreaks could occur. Countries need to make the final push to eliminate plague as a public health problem for the Americas. A further disaggregated risk evaluation is recommended, including identification of foci and possible interactions among areas where plague could emerge or re-emerge. A closer geographical approach and environmental characterization are suggested.

  8. Where does human plague still persist in Latin America?

    Science.gov (United States)

    Schneider, Maria Cristina; Najera, Patricia; Aldighieri, Sylvain; Galan, Deise I; Bertherat, Eric; Ruiz, Alfonso; Dumit, Elsy; Gabastou, Jean Marc; Espinal, Marcos A

    2014-02-01

    Plague is an epidemic-prone disease with a potential impact on public health, international trade, and tourism. It may emerge and re-emerge after decades of epidemiological silence. Today, in Latin America, human cases and foci are present in Bolivia, Brazil, Ecuador, and Peru. The objective of this study is to identify where cases of human plague still persist in Latin America and map areas that may be at risk for emergence or re-emergence. This analysis will provide evidence-based information for countries to prioritize areas for intervention. Evidence of the presence of plague was demonstrated using existing official information from WHO, PAHO, and Ministries of Health. A geo-referenced database was created to map the historical presence of plague by country between the first registered case in 1899 and 2012. Areas where plague still persists were mapped at the second level of the political/administrative divisions (counties). Selected demographic, socioeconomic, and environmental variables were described. Plague was found to be present for one or more years in 14 out of 25 countries in Latin America (1899-2012). Foci persisted in six countries, two of which have no report of current cases. There is evidence that human cases of plague still persist in 18 counties. Demographic and poverty patterns were observed in 11/18 counties. Four types of biomes are most commonly found. 12/18 have an average altitude higher than 1,300 meters above sea level. Even though human plague cases are very localized, the risk is present, and unexpected outbreaks could occur. Countries need to make the final push to eliminate plague as a public health problem for the Americas. A further disaggregated risk evaluation is recommended, including identification of foci and possible interactions among areas where plague could emerge or re-emerge. A closer geographical approach and environmental characterization are suggested.

  9. Human anti-plague monoclonal antibodies protect mice from Yersinia pestis in a bubonic plague model.

    Directory of Open Access Journals (Sweden)

    Xiaodong Xiao

    Full Text Available Yersinia pestis is the etiologic agent of plague that has killed more than 200 million people throughout the recorded history of mankind. Antibiotics may provide little immediate relief to patients who have a high bacteremia or to patients infected with an antibiotic resistant strain of plague. Two virulent factors of Y. pestis are the capsid F1 protein and the low-calcium response (Lcr V-protein or V-antigen that have been proven to be the targets for both active and passive immunization. There are mouse monoclonal antibodies (mAbs against the F1- and V-antigens that can passively protect mice in a murine model of plague; however, there are no anti-Yersinia pestis monoclonal antibodies available for prophylactic or therapeutic treatment in humans. We identified one anti-F1-specific human mAb (m252 and two anti-V-specific human mAb (m253, m254 by panning a naïve phage-displayed Fab library against the F1- and V-antigens. The Fabs were converted to IgG1s and their binding and protective activities were evaluated. M252 bound weakly to peptides located at the F1 N-terminus where a protective mouse anti-F1 mAb also binds. M253 bound strongly to a V-antigen peptide indicating a linear epitope; m254 did not bind to any peptide from a panel of 53 peptides suggesting that its epitope may be conformational. M252 showed better protection than m253 and m254 against a Y, pestis challenge in a plague mouse model. A synergistic effect was observed when the three antibodies were combined. Incomplete to complete protection was achieved when m252 was given at different times post-challenge. These antibodies can be further studied to determine their potential as therapeutics or prophylactics in Y. pestis infection in humans.

  10. Venice: a meeting, a plague, a death

    Directory of Open Access Journals (Sweden)

    Óscar Botasso

    2008-10-01

    Full Text Available Death in Venice is based on the novella of the same name by Thomas Mann, except that in the cinema version the main character, Gustav von Aschenbach, is a musician instead of a writer. Owing to poetic license not always within the layman’s grasp, Luchino Visconti also wished to identify the artist with Gustav Mahler. Beyond such dissimilarities, however, the film is a feasible recreation of the story and a faithful reconstruction of those times: a Venice divorced from its former splendor and invaded by a plague and yet at the same time still able to evoke the captivating, nostalgic legacy of its magnificent past. An ideal scenario indeed for the musical ideas of Mahler, and perfectly reflected in the Midnight Song and the adagietto of his third and fifth symphonies.

  11. Plague in Guinea pigs and its prevention by subunit vaccines.

    Science.gov (United States)

    Quenee, Lauriane E; Ciletti, Nancy; Berube, Bryan; Krausz, Thomas; Elli, Derek; Hermanas, Timothy; Schneewind, Olaf

    2011-04-01

    Human pneumonic plague is a devastating and transmissible disease for which a Food and Drug Administration-approved vaccine is not available. Suitable animal models may be adopted as a surrogate for human plague to fulfill regulatory requirements for vaccine efficacy testing. To develop an alternative to pneumonic plague in nonhuman primates, we explored guinea pigs as a model system. On intranasal instillation of a fully virulent strain, Yersinia pestis CO92, guinea pigs developed lethal lung infections with hemorrhagic necrosis, massive bacterial replication in the respiratory system, and blood-borne dissemination to other organ systems. Expression of the Y. pestis F1 capsule was not required for the development of pulmonary infection; however, the capsule seemed to be important for the establishment of bubonic plague. The mean lethal dose (MLD) for pneumonic plague in guinea pigs was estimated to be 1000 colony-forming units. Immunization of guinea pigs with the recombinant forms of LcrV, a protein that resides at the tip of Yersinia type III secretion needles, or F1 capsule generated robust humoral immune responses. Whereas LcrV immunization resulted in partial protection against pneumonic plague challenge with 250 MLD Y. pestis CO92, immunization with recombinant F1 did not. rV10, a vaccine variant lacking LcrV residues 271-300, elicited protection against pneumonic plague, which seemed to be based on conformational antibodies directed against LcrV. Copyright © 2011 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  12. Plague: A Millenary Infectious Disease Reemerging in the XXI Century.

    Science.gov (United States)

    Grácio, A J Dos Santos; Grácio, Maria Amélia A

    2017-01-01

    Plague, in the Middle Ages known as Black Death, continues to occur at permanent foci in many countries, in Africa, Asia, South America, and even the USA. During the last years outbreaks were reported from at least 3 geographical areas, in all cases after tens of years without reported cases. The recent human plague outbreaks in Libya and Algeria suggest that climatic and other environmental changes in Northern Africa may be favourable for Y. pestis epidemiologic cycle. If so, other Northern Africa countries with plague foci also may be at risk for outbreaks in the near future. It is important to remember that the danger of plague reoccurrence is not limited to the known natural foci, for example, those of Algeria, Angola, and Madagascar. In a general context, it is important that governments know the dangerous impact that this disease may have and that the health and medical community be familiar with the epidemiology, symptoms, treatment, and control of plague, so an appropriated and timely response can be delivered should the worst case happen. Plague can be used as a potential agent of bioterrorism. We have concluded that plague is without a doubt a reemerging infectious disease.

  13. Plague: A Millenary Infectious Disease Reemerging in the XXI Century

    Directory of Open Access Journals (Sweden)

    A. J. dos Santos Grácio

    2017-01-01

    Full Text Available Plague, in the Middle Ages known as Black Death, continues to occur at permanent foci in many countries, in Africa, Asia, South America, and even the USA. During the last years outbreaks were reported from at least 3 geographical areas, in all cases after tens of years without reported cases. The recent human plague outbreaks in Libya and Algeria suggest that climatic and other environmental changes in Northern Africa may be favourable for Y. pestis epidemiologic cycle. If so, other Northern Africa countries with plague foci also may be at risk for outbreaks in the near future. It is important to remember that the danger of plague reoccurrence is not limited to the known natural foci, for example, those of Algeria, Angola, and Madagascar. In a general context, it is important that governments know the dangerous impact that this disease may have and that the health and medical community be familiar with the epidemiology, symptoms, treatment, and control of plague, so an appropriated and timely response can be delivered should the worst case happen. Plague can be used as a potential agent of bioterrorism. We have concluded that plague is without a doubt a reemerging infectious disease.

  14. Plague in Guinea Pigs and Its Prevention by Subunit Vaccines

    Science.gov (United States)

    Quenee, Lauriane E.; Ciletti, Nancy; Berube, Bryan; Krausz, Thomas; Elli, Derek; Hermanas, Timothy; Schneewind, Olaf

    2011-01-01

    Human pneumonic plague is a devastating and transmissible disease for which a Food and Drug Administration–approved vaccine is not available. Suitable animal models may be adopted as a surrogate for human plague to fulfill regulatory requirements for vaccine efficacy testing. To develop an alternative to pneumonic plague in nonhuman primates, we explored guinea pigs as a model system. On intranasal instillation of a fully virulent strain, Yersinia pestis CO92, guinea pigs developed lethal lung infections with hemorrhagic necrosis, massive bacterial replication in the respiratory system, and blood-borne dissemination to other organ systems. Expression of the Y. pestis F1 capsule was not required for the development of pulmonary infection; however, the capsule seemed to be important for the establishment of bubonic plague. The mean lethal dose (MLD) for pneumonic plague in guinea pigs was estimated to be 1000 colony-forming units. Immunization of guinea pigs with the recombinant forms of LcrV, a protein that resides at the tip of Yersinia type III secretion needles, or F1 capsule generated robust humoral immune responses. Whereas LcrV immunization resulted in partial protection against pneumonic plague challenge with 250 MLD Y. pestis CO92, immunization with recombinant F1 did not. rV10, a vaccine variant lacking LcrV residues 271-300, elicited protection against pneumonic plague, which seemed to be based on conformational antibodies directed against LcrV. PMID:21406168

  15. Plague in Iran: its history and current status.

    Science.gov (United States)

    Hashemi Shahraki, Abdolrazagh; Carniel, Elizabeth; Mostafavi, Ehsan

    2016-01-01

    Plague remains a public health concern worldwide, particularly in old foci. Multiple epidemics of this disease have been recorded throughout the history of Iran. Despite the long-standing history of human plague in Iran, it remains difficult to obtain an accurate overview of the history and current status of plague in Iran. In this review, available data and reports on cases and outbreaks of human plague in the past and present in Iran and in neighboring countries were collected, and information was compiled regarding when, where, and how many cases occurred. This paper considers the history of plague in Persia (the predecessor of today's Iran) and has a brief review of plague in countries in the World Health Organization Eastern Mediterranean Region, including a range of countries in the Middle East and North Africa. Since Iran has experienced outbreaks of plague for several centuries, neighboring countries have reported the disease in recent years, the disease can be silent for decades, and the circulation of Yersinia pestis has been reported among rodents and dogs in western Iran, more attention should be paid to disease monitoring in areas with previously reported human cases and in high-risk regions with previous epizootic and enzootic activity.

  16. Plague and landscape resilience in premodern Iceland.

    Science.gov (United States)

    Streeter, Richard; Dugmore, Andrew J; Vésteinsson, Orri

    2012-03-01

    In debates on societal collapse, Iceland occupies a position of precarious survival, defined by not becoming extinct, like Norse Greenland, but having endured, sometimes by the narrowest of margins. Classic decline narratives for late medieval to early modern Iceland stress compounding adversities, where climate, trade, political domination, unsustainable practices, and environmental degradation conspire with epidemics and volcanism to depress the Icelanders and turn the once-proud Vikings and Saga writers into one of Europe's poorest nations. A mainstay of this narrative is the impact of incidental setbacks such as plague and volcanism, which are seen to have compounded and exacerbated underlying structural problems. This research shows that this view is not correct. We present a study of landscape change that uses 15 precisely dated tephra layers spanning the whole 1,200-y period of human settlement in Iceland. These tephras have provided 2,625 horizons of known age within 200 stratigraphic sections to form a high-resolution spatial and temporal record of change. This finding shows short-term (50 y) declines in geomorphological activity after two major plagues in A.D. 15th century, variations that probably mirrored variations in the population. In the longer term, the geomorphological impact of climate changes from the 14th century on is delayed, and landscapes (as well as Icelandic society) exhibit resilience over decade to century timescales. This finding is not a simple consequence of depopulation but a reflection of how Icelandic society responded with a scaling back of their economy, conservation of core functionality, and entrenchment of the established order.

  17. Disease Limits Populations: Plague and Black-Tailed Prairie Dogs

    OpenAIRE

    Cully, Jack F.; Johnson, Tammi L.; Collinge, Sharon K.; Ray, Chris

    2010-01-01

    Plague is an exotic vector-borne disease caused by the bacterium Yersinia pestis that causes mortality rates approaching 100% in black-tailed prairie dogs (Cynomys ludovicianus). We mapped the perimeter of the active portions of black-tailed prairie dog colonies annually between 1999 and 2005 at four prairie dog colony complexes in areas with a history of plague, as well as at two complexes that were located outside the distribution of plague at the time of mapping and had therefore never bee...

  18. Plague in Arab Maghreb, 1940-2015: a review

    Directory of Open Access Journals (Sweden)

    Maliya Alia Malek

    2016-06-01

    Full Text Available We reviewed the epidemiology of 49 plague outbreaks which resulted in about 7,612 cases in 30 localities in the Arabic Maghreb (Mauritania, Morocco, Algeria, Tunisia, Libya and Egypt over 75 years. Between 1940 and 1950, most cases recorded in Morocco (75% and Egypt (20%, resulted from plague imported to Mediterranean harbours and transmitted by rat ectoparasites. In contrast, the re-emergence of plague in the southern part of Western Sahara in 1953 and in northeast Libya in 1976, was traced to direct contact between nomadic populations and infected goats and camels in natural foci, including the consumption of contaminated meat, illustrating this neglected oral route of contamination. Further familial outbreaks were traced to human ectoparasite transmission. Efforts to identify the factors contributing to natural foci may guide where to focus the surveillance of sentinel animals in order to eradicate human plague, if not Y. pestis from the Arab Maghreb.

  19. Solar Variability and the Decline of the Bubonic Plague

    Science.gov (United States)

    2001-10-01

    The bubonic plague was responsible for the deaths of a very large percentage of the population of Europe in ancient times. Leaders of state made promises to “kill off” the plague, were all unsuccessful. It wasn’t the grand promise of a politician, or some new medicinal invention that was responsible for the final decline of the plague. It appears that a chain of events that began 93,000,000 miles away from Earth exerted an impact that lead to the end of the plague’s activity. Some simple changes in solar activity that began in the early 1300’s started the final to break the stranglehold that the plague had on most of Europe. This chain of events will be presented and discussed in this paper.

  20. Understanding the persistence of plague foci in Madagascar.

    Directory of Open Access Journals (Sweden)

    Voahangy Andrianaivoarimanana

    2013-11-01

    Full Text Available Plague, a zoonosis caused by Yersinia pestis, is still found in Africa, Asia, and the Americas. Madagascar reports almost one third of the cases worldwide. Y. pestis can be encountered in three very different types of foci: urban, rural, and sylvatic. Flea vector and wild rodent host population dynamics are tightly correlated with modulation of climatic conditions, an association that could be crucial for both the maintenance of foci and human plague epidemics. The black rat Rattus rattus, the main host of Y. pestis in Madagascar, is found to exhibit high resistance to plague in endemic areas, opposing the concept of high mortality rates among rats exposed to the infection. Also, endemic fleas could play an essential role in maintenance of the foci. This review discusses recent advances in the understanding of the role of these factors as well as human behavior in the persistence of plague in Madagascar.

  1. Understanding the persistence of plague foci in Madagascar.

    Science.gov (United States)

    Andrianaivoarimanana, Voahangy; Kreppel, Katharina; Elissa, Nohal; Duplantier, Jean-Marc; Carniel, Elisabeth; Rajerison, Minoarisoa; Jambou, Ronan

    2013-11-01

    Plague, a zoonosis caused by Yersinia pestis, is still found in Africa, Asia, and the Americas. Madagascar reports almost one third of the cases worldwide. Y. pestis can be encountered in three very different types of foci: urban, rural, and sylvatic. Flea vector and wild rodent host population dynamics are tightly correlated with modulation of climatic conditions, an association that could be crucial for both the maintenance of foci and human plague epidemics. The black rat Rattus rattus, the main host of Y. pestis in Madagascar, is found to exhibit high resistance to plague in endemic areas, opposing the concept of high mortality rates among rats exposed to the infection. Also, endemic fleas could play an essential role in maintenance of the foci. This review discusses recent advances in the understanding of the role of these factors as well as human behavior in the persistence of plague in Madagascar.

  2. 1 Integrating land cover and terrain characteristics to explain plague ...

    African Journals Online (AJOL)

    Kilonzo, B., Mhina, J., Sabuni, C. & Mgode, G. (2005) The role of rodents and small carnivores in plague endemicity ... Interactions between land, people, disease vectors and their hosts. .... diseases transmission: A systematic review. Journal ...

  3. Vegetation habitats and small mammals in a plague endemic area ...

    African Journals Online (AJOL)

    13 small mammal species, potentially related to plague were trapped. Results show that ..... that forest species diversity is negatively affected by human encroachment (Macdonald et al., .... Sensitivity of climate to changes in NDVI. Journal of ...

  4. Understanding the Persistence of Plague Foci in Madagascar

    Science.gov (United States)

    Andrianaivoarimanana, Voahangy; Kreppel, Katharina; Elissa, Nohal; Duplantier, Jean-Marc; Carniel, Elisabeth; Rajerison, Minoarisoa; Jambou, Ronan

    2013-01-01

    Plague, a zoonosis caused by Yersinia pestis, is still found in Africa, Asia, and the Americas. Madagascar reports almost one third of the cases worldwide. Y. pestis can be encountered in three very different types of foci: urban, rural, and sylvatic. Flea vector and wild rodent host population dynamics are tightly correlated with modulation of climatic conditions, an association that could be crucial for both the maintenance of foci and human plague epidemics. The black rat Rattus rattus, the main host of Y. pestis in Madagascar, is found to exhibit high resistance to plague in endemic areas, opposing the concept of high mortality rates among rats exposed to the infection. Also, endemic fleas could play an essential role in maintenance of the foci. This review discusses recent advances in the understanding of the role of these factors as well as human behavior in the persistence of plague in Madagascar. PMID:24244760

  5. Plague in Arab Maghreb, 1940–2015: A Review

    Science.gov (United States)

    Malek, Maliya Alia; Bitam, Idir; Drancourt, Michel

    2016-01-01

    We reviewed the epidemiology of 49 plague outbreaks that resulted in about 7,612 cases in 30 localities in the Arabic Maghreb (Mauritania, Morocco, Algeria, Tunisia, Libya, and Egypt) over 75 years. Between 1940 and 1950, most cases recorded in Morocco (75%) and Egypt (20%), resulted from plague imported to Mediterranean harbors and transmitted by rat ectoparasites. By contrast, the re-emergence of plague in the southern part of Western Sahara in 1953 and in northeast Libya in 1976 was traced to direct contact between nomadic populations and infected goats and camels in natural foci, including the consumption of contaminated meat, illustrating this neglected oral route of contamination. Further familial outbreaks were traced to human ectoparasite transmission. Efforts to identify the factors contributing to natural foci may guide where to focus the surveillance of sentinel animals in order to eradicate human plague, if not Yersinia pestis from the Arab Maghreb. PMID:27376053

  6. Sylvatic plague vaccine and management of prairie dogs

    Science.gov (United States)

    Rocke, Tonie E.

    2012-01-01

    Scientists at the USGS National Wildlife Health Center (NWHC), in collaboration with colleagues at the University of Wisconsin (UW), have developed a sylvatic plague vaccine that shows great promise in protecting prairie dogs against plague (Mencher and others, 2004; Rocke and others, 2010). Four species of prairie dogs reside in the United States and Canada, and all are highly susceptible to plague and regularly experience outbreaks with devastating losses. Along with habitat loss and poisoning, plague has contributed to a significant historical decline in prairie dog populations. By some estimates, prairie dogs now occupy only 1 to 2 percent of their former range (Proctor and others, 2006), with prairie dog colonies being now much smaller and fragmented than they were historically, making individual colonies more vulnerable to elimination by plague (Antolin and others, 2002). At least one species, the Utah prairie dog (Cynomys parvidens) is listed by the U.S. Fish and Wildlife Service (FWS) as "threatened." Controlling plague is a vital concern for ongoing management and conservation efforts for prairie dogs. Current efforts to halt the spread of plague in prairie dog colonies typically rely on dusting individual prairie dog burrows with pesticides to kill plague-infected fleas. Although flea-control insecticides, such as deltamethrin, are useful in stopping plague outbreaks in these prairie dog colonies, dusting of burrows is labor intensive and time consuming and may affect other insects and arthropods. As an alternative approach, NWHC and UW scientists developed a sylvatic plague vaccine (SPV) for prairie dogs that can be delivered via oral bait. Laboratory studies have shown that consumption of this vaccine-laden bait by different prairie dog species results in significant protection against plague infection that can last for at least 9 months (Rocke and others, 2010; Rocke, unpublished). Work has now shifted to optimizing baits and distribution methods for

  7. [The pathogenic ecology research on plague in Qinghai plateau].

    Science.gov (United States)

    Dai, Rui-xia; Wei, Bai-qing; Li, Cun-xiang; Xiong, Hao-ming; Yang, Xiao-yan; Fan, Wei; Qi, Mei-ying; Jin, Juan; Wei, Rong-jie; Feng, Jian-ping; Jin, Xing; Wang, Zu-yun

    2013-12-01

    To study the pathogenic ecology characteristics of plague in Qinghai plateau. Applied molecular biology techniques, conventional technologies and geographic information system (GIS) to study phenotypic traits, plasmid spectrum, genotype, infected host and media spectrum etc.of 952 Yersinia pestis strains in Qinghai plateau plague foci, which were separated from different host and media in different regions during 1954 to 2012. The ecotypes of these strains were Qingzang plateau (91.49%, 871/952),Qilian mountain (6.41%, 61/952) and Microtus fuscus (1.26%, 12/952).83.6% (796/952) of these strains contained all the 4 virulence factors (Fr1, Pesticin1,Virulence antigen, and Pigmentation), 93.26% (367/392) were velogenic strains confirmed by virulence test.725 Yersinia pestis strains were separated from Qinghai plateau plague foci carried 9 kinds of plasmid, among which 713 strains from Marmot himalayan plague foci carried 9 kinds of plasmid, the Mr were 6×10(6), 7×10(6), 23×10(6), 27×10(6), 30×10(6), 45×10(6), 52×10(6), 65×10(6) and 92×10(6) respectively. 12 Yersinia pestis strains were separated from Microtus fuscus plague foci carried only 3 kinds of plasmid, the Mr were 6×10(6), 45×10(6), 65×10(6). Meanwhile, the strains carrying large plasmid (52×10(6), 65×10(6) and 92×10(6)) were only distributed in particular geographical location, which had the category property. The research also confirmed that 841 Yersinia pestis strains from two kinds of plague foci in Qinghai plateau had 11 genomovars. The strains of Marmot himalayan plague foci were given priority to genomovar 5 and 8, amounted to 611 strains, genomovar 8 accounted for 56.00% (471/841), genomovar 5 accounted for 23.07% (194/841). Besides, 3 new genomovars, including new 1(62 strains), new 2(52 strains), new 3(48 strains) were newly founded, and 12 strains of Microtus fuscus plague foci were genomovar 14. The main host and media of Qinghai plateau plague foci directly affected the spatial

  8. Paleoclimate and bubonic plague: a forewarning of future risk?

    Science.gov (United States)

    McMichael, Anthony J

    2010-08-27

    Pandemics of bubonic plague have occurred in Eurasia since the sixth century AD. Climatic variations in Central Asia affect the population size and activity of the plague bacterium's reservoir rodent species, influencing the probability of human infection. Using innovative time-series analysis of surrogate climate records spanning 1,500 years, a study in BMC Biology concludes that climatic fluctuations may have influenced these pandemics. This has potential implications for health risks from future climate change.

  9. Resistance to plague among black-tailed prairie dog populations

    Science.gov (United States)

    Rocke, Tonie E.; Williamson, Judy; Cobble, Kacy R.; Busch, Joseph D.; Antolin, Michael F.; Wagner, David M.

    2012-01-01

    In some rodent species frequently exposed to plague outbreaks caused by Yersinia pestis, resistance to the disease has evolved as a population trait. As a first step in determining if plague resistance has developed in black-tailed prairie dogs (Cynomys ludovicianus), animals captured from colonies in a plague-free region (South Dakota) and two plague-endemic regions (Colorado and Texas) were challenged with Y. pestis at one of three doses (2.5, 250, or 2500 mouse LD50s). South Dakota prairie dogs were far more susceptible to plague than Colorado and Texas prairie dogs (pdogs were quite similar in their response, with overall survival rates of 50% and 60%, respectively. Prairie dogs from these states were heterogenous in their response, with some animals dying at the lowest dose (37% and 20%, respectively) and some surviving even at the highest dose (29% and 40%, respectively). Microsatellite analysis revealed that all three groups were distinct genetically, but further studies are needed to establish a genetic basis for the observed differences in plague resistance.

  10. Potential corridors and barriers for plague spread in central Asia

    Science.gov (United States)

    2013-01-01

    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

  11. Potential corridors and barriers for plague spread in Central Asia.

    Science.gov (United States)

    Wilschut, Liesbeth I; Addink, Elisabeth A; Heesterbeek, Hans; Heier, Lise; Laudisoit, Anne; Begon, Mike; Davis, Stephen; Dubyanskiy, Vladimir M; Burdelov, Leonid A; de Jong, Steven M

    2013-10-31

    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. 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. 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

  12. CCR5 polymorphism and plague resistance in natural populations of the black rat in Madagascar

    OpenAIRE

    Tollenaere, C., Pernechele, B., Mäkinen, H., Parratt, S., Nemeth, M., Kovacs, G., Levente, K. Tack, A.; Rahalison, L.; Ranjalahy, M.; Rahelinirina, S.; Duplantier, Jean-Marc; Brouat, Carine

    2008-01-01

    Madagascar remains one of the world's largest plague foci. The black rat, Rattus rattus, is the main reservoir of plague in rural areas. This species is highly susceptible to plague in plague-free areas (low-altitude regions), whereas rats from the plague focus areas (central highlands) have evolved a disease-resistance polymorphism. We used the candidate gene CCR5 to investigate the genetic basis of plague resistance in R. rattus. We found a unique non-synonymous substitution (H184R) in a fu...

  13. Population decline and plague in late medieval Norway.

    Science.gov (United States)

    Brothen, J A

    1996-01-01

    Norwegian scholars have engaged in considerable research over the last half century in an attempt to assess the impact of the Black Plague of 1349 on population and society in Norway. Evidence has been put forward relating the incidence of plague to a continuance of population decline over the two centuries following its initial introduction. Estimates of population decline in Norway between 1350 and 1550 indicate a reduction by as much as 65%. Two directions of study have emerged, one concentrating on land abandonment known as the "Ødegard Project." The other is represented by the recent works of Ole Jørgen Benedictow presenting epidemiological and osteo-archaeological research. An examination of the available literature raises questions concerning the degree to which plague, and its recurrence, directly affected population decline in Norway during the Late Middle Ages. While evidence of the virulence of the plague and the degree of farm abandonment is compelling, a direct relationship to population decline may not be as great as implied by the research. Other explanatory factors, especially social and economic responses to plague, have been given limited attention.

  14. Zoonoses As Ecological Entities: A Case Review of Plague.

    Science.gov (United States)

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

    2016-10-01

    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.

  15. [ON SOME DEBATABLE PROBLEMS OF THE NATURAL NIDALITY OF PLAGUE].

    Science.gov (United States)

    Verzhutsky, D B; Balakhonov, S V

    2016-01-01

    The communication substantiates the opinion that the theory of natural nidality of plague; which is based on the fundamental recognition that fleas play a leading role in the transmission and accumulation of the plague pathogen, cannot be disproved or substantially changed on the alternative weakly reasoned assumptions and hypotheses. All its "bottlenecks" are quite understandable when considering the long-term volumetric materials that have been gathered directly in nature and generalized in multiple publications. Plague is an obligate transmissive infection; its, agent is a highly specialized parasite that is completely associated in its vital activity with the only group of the blood-sucking insects--fleas and that is transmitted through periodic colonization of warm-blooded animals for a short time. All other types of plague microbe persistence in nature are either occasional or minor and do not play any significant role in pathogen persistence in the natural foci of this disease. There are no strong grounds for seriously considering the attempts to revise the main points of the theory of natural nidality of plague, which are widely held in current academic publications.

  16. CCR5 polymorphism and plague resistance in natural populations of the black rat in Madagascar.

    Science.gov (United States)

    Tollenaere, C; Rahalison, L; Ranjalahy, M; Rahelinirina, S; Duplantier, J-M; Brouat, C

    2008-12-01

    Madagascar remains one of the world's largest plague foci. The black rat, Rattus rattus, is the main reservoir of plague in rural areas. This species is highly susceptible to plague in plague-free areas (low-altitude regions), whereas rats from the plague focus areas (central highlands) have evolved a disease-resistance polymorphism. We used the candidate gene CCR5 to investigate the genetic basis of plague resistance in R. rattus. We found a unique non-synonymous substitution (H184R) in a functionally important region of the gene. We then compared (i) CCR5 genotypes of dying and surviving plague-challenged rats and (ii) CCR5 allelic frequencies in plague focus and plague-free populations. Our results suggested a higher prevalence of the substitution in resistant animals compared to susceptible individuals, and a tendency for higher frequencies in plague focus areas compared to plague-free areas. Therefore, the CCR5 polymorphism may be involved in Malagasy black rat plague resistance. CCR5 and other undetermined plague resistance markers may provide useful biological information about host evolution and disease dynamics.

  17. A Taxonomic Update of Small Mammal Plague Reservoirs in South America.

    Science.gov (United States)

    Bonvicino, Cibele R; Oliveira, João A; Cordeiro-Estrela, Pedro; D'andrea, Paulo S; Almeida, Alzira M P

    2015-10-01

    Plague is a disease of epidemic potential that may emerge with discontinuous outbreaks. In South America, 50 wild rodent species have been identified as plague reservoirs, in addition to one lagomorph and two marsupials. To review the nomenclature of plague reservoirs, we examined specimens collected in plague foci, carried out new surveys in Brazilian plague regions, and re-evaluated the nomenclature of South American reservoirs on the basis of the current literature. Five of the 15 species involved with plague in Argentina, three of 10 species involved with plague in Bolivia, three of the seven species involved with plague in Peru, five of the nine species involved with plague in Ecuador, and six of the nine species involved with plague in Brazil have undergone taxonomic changes. In the last 20 years, plague cases were recorded in Bolivia, Brazil, Ecuador, and Peru. These four countries have a high rodent species richness in plague foci, a fact that may be decisive for the maintenance of plague in the wild.

  18. [The spread of the plague: A sciento-historiographic review].

    Science.gov (United States)

    Cuadrada, Coral

    2015-01-01

    There is still uncertainty about the diagnosis and nature of the plague; some scholars have been forced to abandon certainties and be filled with doubts: from believing that the mediaeval Black Plague was, in reality, the bubonic plague (although with unusual characteristics) to stating that there is very little evidence to support a retro-diagnosis. This article looks at this in depth, not only reviewing the historiography but also giving new interpretations which question previous hypotheses through research on images of the time, comparing them to the most recent investigative data. Two primary sources are analysed: Renaissance treaties written by four Italian doctors: Michele Savonarola, Marsilio Ficino, Leonardo Fioravanti and Gioseffo Daciano; and iconography: an illustrated manuscript of the Decameron by Giovanni Boccaccio and a Hebrew Haggadah from the XIVth century. The results are compared to the most recent research on DNA and in micropaleontology.

  19. Genotyping, Orientalis-like Yersinia pestis, and plague pandemics.

    Science.gov (United States)

    Drancourt, Michel; Roux, Véronique; Dang, La Vu; Tran-Hung, Lam; Castex, Dominique; Chenal-Francisque, Viviane; Ogata, Hiroyuki; Fournier, Pierre-Edouard; Crubézy, Eric; Raoult, Didier

    2004-09-01

    Three pandemics have been attributed to plague in the last 1,500 years. Yersinia pestis caused the third, and its DNA was found in human remains from the second. The Antiqua biovar of Y. pestis may have caused the first pandemic; the other two biovars, Medievalis and Orientalis, may have caused the second and third pandemics, respectively. To test this hypothesis, we designed an original genotyping system based on intergenic spacer sequencing called multiple spacer typing (MST). We found that MST differentiated every biovar in a collection of 36 Y. pestis isolates representative of the three biovars. When MST was applied to dental pulp collected from remains of eight persons who likely died in the first and second pandemics, this system identified original sequences that matched those of Y. pestis Orientalis. These data indicate that Y. pestis caused cases of Justinian plague. The two historical plague pandemics were likely caused by Orientalis-like strains.

  20. Wet climate and transportation routes accelerate spread of human plague

    Science.gov (United States)

    Xu, Lei; Stige, Leif Chr.; Kausrud, Kyrre Linné; Ben Ari, Tamara; Wang, Shuchun; Fang, Xiye; Schmid, Boris V.; Liu, Qiyong; Stenseth, Nils Chr.; Zhang, Zhibin

    2014-01-01

    Currently, large-scale transmissions of infectious diseases are becoming more closely associated with accelerated globalization and climate change, but quantitative analyses are still rare. By using an extensive dataset consisting of date and location of cases for the third plague pandemic from 1772 to 1964 in China and a novel method (nearest neighbour approach) which deals with both short- and long-distance transmissions, we found the presence of major roads, rivers and coastline accelerated the spread of plague and shaped the transmission patterns. We found that plague spread velocity was positively associated with wet conditions (measured by an index of drought and flood events) in China, probably due to flood-driven transmission by people or rodents. Our study provides new insights on transmission patterns and possible mechanisms behind variability in transmission speed, with implications for prevention and control measures. The methodology may also be applicable to studies of disease dynamics or species movement in other systems. PMID:24523275

  1. Plague: A Disease Which Changed the Path of Human Civilization.

    Science.gov (United States)

    Bramanti, Barbara; Stenseth, Nils Chr; Walløe, Lars; Lei, Xu

    2016-01-01

    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.

  2. Predicting Potential Risk Areas of Human Plague for the Western Usambara Mountains, Lushoto District, Tanzania

    Science.gov (United States)

    Neerinckx, Simon; Peterson, A. Townsend; Gulinck, Hubert; Deckers, Jozef; Kimaro, Didas; Leirs, Herwig

    2010-01-01

    A natural focus of plague exists in the Western Usambara Mountains of Tanzania. Despite intense research, questions remain as to why and how plague emerges repeatedly in the same suite of villages. We used human plague incidence data for 1986–2003 in an ecological-niche modeling framework to explore the geographic distribution and ecology of human plague. Our analyses indicate that plague occurrence is related directly to landscape-scale environmental features, yielding a predictive understanding of one set of environmental factors affecting plague transmission in East Africa. Although many environmental variables contribute significantly to these models, the most important are elevation and Enhanced Vegetation Index derivatives. Projections of these models across broader regions predict only 15.5% (under a majority-rule threshold) or 31,997 km2 of East Africa as suitable for plague transmission, but they successfully anticipate most known foci in the region, making possible the development of a risk map of plague. PMID:20207880

  3. Plague mortality and demographic depression in later medieval England.

    Science.gov (United States)

    Poos, L R

    1981-01-01

    Both direct and indirect evidence implies that England experienced a lengthy period of stagnant or declining population during the later fourteenth and fifteenth centuries. The Black Death of 1348-1349 had brought about profound changes in England's agrarian economy, and this subsequent demographic depression is most commonly interpreted by historians as the result of plague mortality, recurring in severe outbreaks after the disease's introduction into the country. This paper reviews the evidence and assumptions behind this interpretation, in light of recent research by historical demographers and epidemiologists into bubonic plague epidemics and general mortality crises during the post-medieval period.

  4. Paleoclimate and bubonic plague: a forewarning of future risk?

    Directory of Open Access Journals (Sweden)

    McMichael Anthony J

    2010-08-01

    Full Text Available Abstract Pandemics of bubonic plague have occurred in Eurasia since the sixth century ad. Climatic variations in Central Asia affect the population size and activity of the plague bacterium's reservoir rodent species, influencing the probability of human infection. Using innovative time-series analysis of surrogate climate records spanning 1,500 years, a study in BMC Biology concludes that climatic fluctuations may have influenced these pandemics. This has potential implications for health risks from future climate change. See research article http://www.biomedcentral.com/1741-7007/8/112

  5. [The epidemiology and etiology research of Tibetan sheep plague in Qinghai plateau].

    Science.gov (United States)

    Wei, Baiqing; Xiong, Haoming; Yang, Xiaoyan; Yang, Yonghai; Qi, Meiying; Jin, Juan; Xin, Youquan; Li, Xiang; Yang, Hanqing; Han, Xiumin; Dai, Ruixia

    2015-03-01

    To identify the epidemiology and etiology characteristics of Tibetan sheep plague in Qinghai plateau. The background materials of Qinghai Tibetan sheep plague found during 1975 to 2009 were summarized, the regional, time and interpersonal distribution, infection routes, ecological factors for the spread were used to analyze; followed by choosing 14 Yersinia pestis strains isolated from such sheep for biochemical test, toxicity test, virulence factors identification, plasmid analysis, and DFR genotype. From 1975 to 2009, 14 Yersinia pestis strains were isolated from Tibetan sheep in Qinghai province. Tibetan sheep, as the infection source, had caused 10 cases of human plague, 25 plague patients, and 13 cases of death. All of the initial cases were infected due to eating Tibetan sheep died of plague; followed by cases due to contact of plague patients, while all the initial cases were bubonic plague. Cases of bubonic plague developed into secondary pneumonic plague and septicemia plague were most popular and with high mortality. Most of the Tibetan sheep plague and human plague occurred in Gannan ecological zone in southern Gansu province, which was closely related to its unique ecological and geographical landscape. Tibetan sheep plague coincided with human plague caused by Tibetan sheep, especially noteworthy was that November (a time for marmots to start their dormancy) witnesses the number of Yersinia pestis strains isolated from Tibetan sheep and human plague cases caused by Tibetan sheep. This constituted the underlying cause that the epidemic time of Tibetan sheep plague lags obviously behind that of the Marmot plague. It was confirmed in the study that all the 14 strains were of Qinghai-Tibet Plateau ecotype, with virulence factors evaluation and toxicity test demonstrating strains as velogenic. As found in the (Different Region) DFR genotyping, the strains isolated from Yushu county and Zhiduo county were genomovar 5, the two strain isolated from Nangqian

  6. [Advance to the research of the climate factor effect on the distribution of plague].

    Science.gov (United States)

    Zhang, A P; Wei, R J; Xiong, H M; Wang, Z Y

    2016-05-01

    Plague is an anthropozoonotic disease caused by the Yersinia pestis ,which developed by many factors including local climate factors. In recent years, more and more studies on the effects of climate on plague were conducted. According to the researches, climate factors (mainly the rainfall and temperature) affected the development and distribution of plague by influencing the abundance of plague host animals and fleas index. The climate also affected the epidemic dynamics and the scope of plague. There were significant differences existing in the influence of climate on the palgue developed in the north and south China. In the two different plague epidemic systems, the solitary Daurian ground squirrel-flea-plague and the social Mongolian gerbil-flea-plague, the obvious population differences existed among the responses of the host animal to the climate changes. Although the internal relationship between the rainfall, the flea index, the density of rodents and the plague supported the nutritional cascade hypothesis, it can not prove that there is a clear causality between the occurrence of plague and rainfall. So the influence of climate factors on plague distribution can only be used for early forecasting and warning of the plague.

  7. Susceptibility to Yersinia pestis experimental infection in wild Rattus rattus, reservoir of plague in Madagascar.

    Science.gov (United States)

    Tollenaere, C; Rahalison, L; Ranjalahy, M; Duplantier, J-M; Rahelinirina, S; Telfer, S; Brouat, C

    2010-06-01

    In Madagascar, the black rat, Rattus rattus, is the main reservoir of plague (Yersinia pestis infection), a disease still responsible for hundreds of cases each year in this country. This study used experimental plague challenge to assess susceptibility in wild-caught rats to better understand how R. rattus can act as a plague reservoir. An important difference in plague resistance between rat populations from the plague focus (central highlands) and those from the plague-free zone (low altitude area) was confirmed to be a widespread phenomenon. In rats from the plague focus, we observed that sex influenced plague susceptibility, with males slightly more resistant than females. Other individual factors investigated (weight and habitat of sampling) did not affect plague resistance. When infected at high bacterial dose (more than 10⁵ bacteria injected), rats from the plague focus died mainly within 3-5 days and produced specific antibodies, whereas after low-dose infection (plague resistance level and the course of infection in the black rat would contribute to a better understanding of plague circulation in Madagascar.

  8. MOLECULAR AND EVOLUTIONARY INSIGHTS INTO YERSINIA PESTIS; HARBINGER OF PLAGUE

    Directory of Open Access Journals (Sweden)

    Stephen Anderson

    2013-10-01

    Full Text Available Plague has been the scourge of mankind for millennia; yet it was not until the late 18th Century that its causative agent was identified. Prokaryotic Y. pestis is responsible for plague; bacilli are consumed through arthropod feeding on infected rodential reservoirs. Arthropod uptake is essential for transmission as the bacilli proliferate within their gut before being refluxed into new mammalian hosts. Genomic analysis has elucidated the mechanisms facilitating this cycle along with the means by which bacilli acquire their characteristic virulence. Increasing our understanding of the evolution of Y. pestis provides putative avenues for future research. Whilst plague is considered a disease of the past by many, it interaction with humanity continues across various geographic foci. The rise of antibiotic resistant bacteria threatens to bring this ancient foe once again to the fore through the acquisition of drug resistance. This review will detail notable advances of the past decade enabling the elusive possibility of a universal vaccine for the three manifestations of plague. Development of suitable vaccines before drug resistant strains emerge is paramount. Researchers are pitted in an on-going race against bacterial evolution.

  9. Shutt up: bubonic plague and quarantine in early modern England.

    Science.gov (United States)

    Newman, Kira L S

    2012-01-01

    The outbreak of bubonic plague that struck London and Westminster in 1636 provoked the usual frenzied response to epidemics, including popular flight and government-mandated quarantine. The government asserted that plague control measures were acts of public health for the benefit of all. However, contrary to this government narrative of disease prevention there was a popular account that portrayed quarantine and isolation as personal punishment rather than prudent policy. In examining the 1636 outbreak on the parish as well as the individual level, reasons for this inconsistency between official and unofficial perspectives emerge. Quarantine and its effects were not classless, and its implementation was not always strictly in the name of public health. Government application of quarantine was remarkably effective, but it could never be uncontroversial both because of circumstances and because of misuse. The flight of the wealthiest from London and Westminster left only the more socially vulnerable to be quarantined. Though plague policy was financially sensitive to the poorest, it was costly to the middling sort. Another cause of controversy was the government's use of quarantine as a punishment to control individuals found breaking other laws. Though not widely publicized, popular narratives continually included grievances about the cruelty and inequity of quarantine and the militaristic nature of its implementation. Despite these objections, quarantine remained a staple of the government response to plague outbreaks throughout the seventeenth century.

  10. Plague Epidemic s in Syria b etween XIII - XV. Centuries

    Directory of Open Access Journals (Sweden)

    Esra ATMACA

    2015-07-01

    Full Text Available Epidemic diseases that cause mass death has been one of the greatest fears of the society in the past century Usually due to poor living conditions, poverty, the inadequate treatment. Plague is one of them. Plague word is sometimes used synonymously with t he word tâûn, sometimes considered to be a greater sense of the Word plague. These outbreaks occured repeatedly in human society and many times occured between XIII - XV. centuries. Our research aims to examine the plague occured in Syria in the Mamluk state domination discussed period. One of the outbreaks have occured in the period between the years 1347 - 1351. Epidemic was looming at the same time with the European named the black death or large extinction. Many people have been killed in Syria as in other places where the epidemic has spread. Rumors about them are given in the source is situated in the form of the issuance of the number of people who died in one day and sometimes the total number of deaths took place at a given date range. In this study, we aimed to determine which is more severe than the others in the outbreak, to assess the rumor about the number of deaths from this cause, to reveal the difficulties of the funeral of the dead, to uncover practices that people do to get rid of this disease.

  11. Second Language Teacher Education: The Problems That Plague Us.

    Science.gov (United States)

    Tedick, Diane J.; Walker, Constance L.

    1994-01-01

    A discussion of why change is needed in second-language teacher education considers five problems that plague the profession: lack of consideration of first- and second-language interdependence; fragmentation/isolation of language arts fields; view of language as "object;" focus on methodology; and failure to connect language and culture. (80…

  12. Plague: Infections of Companion Animals and Opportunities for Intervention

    Directory of Open Access Journals (Sweden)

    Petra C.F. Oyston

    2011-06-01

    Full Text Available Plague is a zoonotic disease, normally circulating in rodent populations, transmitted to humans most commonly through the bite of an infected flea vector. Secondary infection of the lungs results in generation of infectious aerosols, which pose a significant hazard to close contacts. In enzootic areas, plague infections have been reported in owners and veterinarians who come into contact with infected pets. Dogs are relatively resistant, but can import infected fleas into the home. Cats are acutely susceptible, and can present a direct hazard to health. Reducing roaming and hunting behaviours, combined with flea control measures go some way to reducing the risk to humans. Various vaccine formulations have been developed which may be suitable to protect companion animals from contracting plague, and thus preventing onward transmission to man. Since transmission has resulted in a number of fatal cases of plague, the vaccination of domestic animals such as cats would seem a low cost strategy for reducing the risk of infection by this serious disease in enzootic regions.

  13. The abundance threshold for plague as a critical percolation phenomenon

    DEFF Research Database (Denmark)

    Davis, S; Trapman, P; Leirs, H

    2008-01-01

    . However, no natural examples have been reported. The central question of interest in percolation theory 4 , the possibility of an infinite connected cluster, corresponds in infectious disease to a positive probability of an epidemic. Archived records of plague (infection with Yersinia pestis...

  14. A curve of thresholds governs plague epizootics in Central Asia

    DEFF Research Database (Denmark)

    Reijniers, Jonas; Davis, Stephen; Begon, Mike

    2012-01-01

    , it is common to assume a threshold defined by the ratio of vector and host abundances. Here, we show in contrast, both from field data and model simulations, that for plague (Yersinia pestis) in Kazakhstan, the invasion threshold quantity is based on the product of its host (Rhombomys opimus) and vector...

  15. Immunogenicity and protective immunity against bubonic plague and pneumonic plague by immunization of mice with the recombinant V10 antigen, a variant of LcrV.

    Science.gov (United States)

    DeBord, Kristin L; Anderson, Deborah M; Marketon, Melanie M; Overheim, Katie A; DePaolo, R William; Ciletti, Nancy A; Jabri, Bana; Schneewind, Olaf

    2006-08-01

    In contrast to Yersinia pestis LcrV, the recombinant V10 (rV10) variant (lacking residues 271 to 300) does not suppress the release of proinflammatory cytokines by immune cells. Immunization with rV10 generates robust antibody responses that protect mice against bubonic plague and pneumonic plague, suggesting that rV10 may serve as an improved plague vaccine.

  16. Levofloxacin cures experimental pneumonic plague in African green monkeys.

    Directory of Open Access Journals (Sweden)

    Robert Colby Layton

    Full Text Available BACKGROUND: Yersinia pestis, the agent of plague, is considered a potential bioweapon due to rapid lethality when delivered as an aerosol. Levofloxacin was tested for primary pneumonic plague treatment in a nonhuman primate model mimicking human disease. METHODS AND RESULTS: Twenty-four African Green monkeys (AGMs, Chlorocebus aethiops were challenged via head-only aerosol inhalation with 3-145 (mean = 65 50% lethal (LD(50 doses of Y. pestis strain CO92. Telemetered body temperature >39 °C initiated intravenous infusions to seven 5% dextrose controls or 17 levofloxacin treated animals. Levofloxacin was administered as a "humanized" dose regimen of alternating 8 mg/kg and 2 mg/kg 30-min infusions every 24-h, continuing until animal death or 20 total infusions, followed by 14 days of observation. Fever appeared at 53-165 h and radiographs found multilobar pneumonia in all exposed animals. All control animals died of severe pneumonic plague within five days of aerosol exposure. All 16 animals infused with levofloxacin for 10 days survived. Levofloxacin treatment abolished bacteremia within 24 h in animals with confirmed pre-infusion bacteremia, and reduced tachypnea and leukocytosis but not fever during the first 2 days of infusions. CONCLUSION: Levofloxacin cures established pneumonic plague when treatment is initiated after the onset of fever in the lethal aerosol-challenged AGM nonhuman primate model, and can be considered for treatment of other forms of plague. Levofloxacin may also be considered for primary presumptive-use, multi-agent antibiotic in bioterrorism events prior to identification of the pathogen.

  17. Predicting Potential Risk Areas of Human Plague for the Western Usambara Mountains, Lushoto District, Tanzania

    DEFF Research Database (Denmark)

    Neerinckx, Simon; Peterson, A Townsend; Gulinck, Hubert

    2010-01-01

    A natural focus of plague exists in the Western Usambara Mountains of Tanzania. Despite intense research, questions remain as to why and how plague emerges repeatedly in the same suite of villages. We used human plague incidence data for 1986-2003 in an ecological-niche modeling framework...... to explore the geographic distribution and ecology of human plague. Our analyses indicate that plague occurrence is related directly to landscape-scale environmental features, yielding a predictive understanding of one set of environmental factors affecting plague transmission in East Africa. Although many...... environmental variables contribute significantly to these models, the most important are elevation and Enhanced Vegetation Index derivatives. Projections of these models across broader regions predict only 15.5% (under a majority-rule threshold) or 31,997 km2 of East Africa as suitable for plague transmission...

  18. Geographic distribution and ecological niche of plague in sub-Saharan Africa

    DEFF Research Database (Denmark)

    Neerinckx, Simon B; Peterson, Andrew T; Gulinck, Hubert

    2008-01-01

    Background Plague is a rapidly progressing, serious illness in humans that is likely to be fatal if not treated. It remains a public health threat, especially in sub-Saharan Africa. In spite of plague's highly focal nature, a thorough ecological understanding of the general distribution pattern...... of plague across sub-Saharan Africa has not been established to date. In this study, we used human plague data from sub-Saharan Africa for 1970-2007 in an ecological niche modeling framework to explore the potential geographic distribution of plague and its ecological requirements across Africa. Results We...... predict a broad potential distributional area of plague occurrences across sub-Saharan Africa. General tests of model's transferability suggest that our model can anticipate the potential distribution of plague occurrences in Madagascar and northern Africa. However, generality and predictive ability tests...

  19. Quick control of bubonic plague outbreak in Uttar Kashi, India.

    Science.gov (United States)

    Mittal, Veena; Rana, U V S; Jain, S K; Kumar, Kaushal; Pal, I S; Arya, R C; Ichhpujani, R L; Lal, Shiv; Agarwal, S P

    2004-12-01

    A localized outbreak of bubonic plague occurred in village Dangud (population 332), district Uttar Kashi, Uttaranchal, India in the second week of October 2004. 8 cases were considered outbreak associated based on their clinical and epidemiological characteristics; 3 (27.3%) of them died within 48 hours of developing illness. All the 3 fatal cases and five surviving cases had enlargement of inguinal lymph nodes. None of them had pneumonia. The age of the cases ranged from 23-70 years and both sexes were affected. No such illness was reported from adjoining villages. The outbreak was fully contained within two weeks of its onset by supervised comprehensive chemoprophylaxis using tetracycline. A total of approximately 1250 persons were given chemoprophylaxis in three villages. There was no clear history of rat fall in the village. No flea was found on rodents or animals. 16 animal serum samples were found to be negative for antibodies against F-1 antigen of Y. pestis. However, Y. pestis was isolated from two rodents (Rattus rattus and Mus musculus) trapped in the village. One case and three animal sera showed borderline sero-positivity against rickettsial infection. The diagnosis of plague was confirmed by detection of four fold rise of antibody titre against F-1 antigen of Yersinia pestis in paired sera of three cases (one of the WHO approved criteria of diagnosis of confirmed plague). This outbreak and the occurrence of earlier outbreaks of plague in Surat (Gujarat) and Beed (Maharashtra) in 1994 and in district Shimla (Himachal Pradesh) in 2002 confirm that plague infection continue to exist in sylvatic foci in many parts of India which is transmitted to humans occasionally. Thus, there is a strong need for the States to monitor the plague activity in known sylvatic foci regularly and have a system of surveillance to facilitate prompt diagnosis and treatment of cases to control the disease. This investigation highlights that with high index of suspicion the

  20. Sylvatic plague vaccine: a new tool for conservation of threatened and endangered species?

    Science.gov (United States)

    Abbott, Rachel C; Osorio, Jorge E; Bunck, Christine M; Rocke, Tonie E

    2012-09-01

    Plague, a disease caused by Yersinia pestis introduced into North America about 100 years ago, is devastating to prairie dogs and the highly endangered black-footed ferret. Current attempts to control plague in these species have historically relied on insecticidal dusting of prairie dog burrows to kill the fleas that spread the disease. Although successful in curtailing outbreaks in most instances, this method of plague control has significant limitations. Alternative approaches to plague management are being tested, including vaccination. Currently, all black-footed ferret kits released for reintroduction are vaccinated against plague with an injectable protein vaccine, and even wild-born kits are captured and vaccinated at some locations. In addition, a novel, virally vectored, oral vaccine to prevent plague in wild prairie dogs has been developed and will soon be tested as an alternative, preemptive management tool. If demonstrated to be successful, oral vaccination of selected prairie dog populations could decrease the occurrence of plague epizootics in key locations, thereby reducing the source of bacteria while avoiding the indiscriminate environmental effects of dusting. Just as rabies in wild carnivores has largely been controlled through an active surveillance and oral vaccination program, we believe an integrated plague management strategy would be similarly enhanced with the addition of a cost-effective, bait-delivered, sylvatic plague vaccine for prairie dogs. Control of plague in prairie dogs, and potentially other rodents, would significantly advance prairie dog conservation and black-footed ferret recovery.

  1. Sylvatic plague vaccine: A new tool for conservation of threatened and endangered species?

    Science.gov (United States)

    Abbott, Rachel C.; Osorio, Jorge E.; Bunck, Christine M.; Rocke, Tonie E.

    2012-01-01

    Plague, a disease caused by Yersinia pestis introduced into North America about 100 years ago, is devastating to prairie dogs and the highly endangered black-footed ferret. Current attempts to control plague in these species have historically relied on insecticidal dusting of prairie dog burrows to kill the fleas that spread the disease. Although successful in curtailing outbreaks in most instances, this method of plague control has significant limitations. Alternative approaches to plague management are being tested, including vaccination. Currently, all black-footed ferret kits released for reintroduction are vaccinated against plague with an injectable protein vaccine, and even wild-born kits are captured and vaccinated at some locations. In addition, a novel, virally vectored, oral vaccine to prevent plague in wild prairie dogs has been developed and will soon be tested as an alternative, preemptive management tool. If demonstrated to be successful, oral vaccination of selected prairie dog populations could decrease the occurrence of plague epizootics in key locations, thereby reducing the source of bacteria while avoiding the indiscriminate environmental effects of dusting. Just as rabies in wild carnivores has largely been controlled through an active surveillance and oral vaccination program, we believe an integrated plague management strategy would be similarly enhanced with the addition of a cost-effective, bait-delivered, sylvatic plague vaccine for prairie dogs. Control of plague in prairie dogs, and potentially other rodents, would significantly advance prairie dog conservation and black-footed ferret recovery.

  2. A non-stationary relationship between global climate phenomena and human plague incidence in Madagascar.

    Science.gov (United States)

    Kreppel, Katharina S; Caminade, Cyril; Telfer, Sandra; Rajerison, Minoarison; Rahalison, Lila; Morse, Andy; Baylis, Matthew

    2014-10-01

    Plague, a zoonosis caused by Yersinia pestis, is found in Asia and the Americas, but predominantly in Africa, with the island of Madagascar reporting almost one third of human cases worldwide. Plague's occurrence is affected by local climate factors which in turn are influenced by large-scale climate phenomena such as the El Niño Southern Oscillation (ENSO). The effects of ENSO on regional climate are often enhanced or reduced by a second large-scale climate phenomenon, the Indian Ocean Dipole (IOD). It is known that ENSO and the IOD interact as drivers of disease. Yet the impacts of these phenomena in driving plague dynamics via their effect on regional climate, and specifically contributing to the foci of transmission on Madagascar, are unknown. Here we present the first analysis of the effects of ENSO and IOD on plague in Madagascar. We use a forty-eight year monthly time-series of reported human plague cases from 1960 to 2008. Using wavelet analysis, we show that over the last fifty years there have been complex non-stationary associations between ENSO/IOD and the dynamics of plague in Madagascar. We demonstrate that ENSO and IOD influence temperature in Madagascar and that temperature and plague cycles are associated. The effects on plague appear to be mediated more by temperature, but precipitation also undoubtedly influences plague in Madagascar. Our results confirm a relationship between plague anomalies and an increase in the intensity of ENSO events and precipitation. This work widens the understanding of how climate factors acting over different temporal scales can combine to drive local disease dynamics. Given the association of increasing ENSO strength and plague anomalies in Madagascar it may in future be possible to forecast plague outbreaks in Madagascar. The study gives insight into the complex and changing relationship between climate factors and plague in Madagascar.

  3. Bibliographic Index to the Plague (1965-1970)

    Science.gov (United States)

    1975-11-18

    Shiko, Infection Promoting Activity of Htigh Molecular Weight Microbial Polysaccharides on Mouse Peritoneal Infections With irasteurella Pestis. .J...Plague Microbe 710. Admnov, A. K., Molecular Mechanisms of Information Exchange and the Variability of Organisms. In: Microbiol. and Inminol. of Dread...Bibliog.: 6refs. Ref.: R.J " Biologia , 99 2593 798. Bakhrakh, Ye. E., F. K. Drozdovskava and L. I. Glushko, The Affect of the Reduction-Oxidation State of

  4. Human bubonic plague transmitted by a domestic cat scratch.

    Science.gov (United States)

    Weniger, B G; Warren, A J; Forseth, V; Shipps, G W; Creelman, T; Gorton, J; Barnes, A M

    1984-02-17

    Bubonic plague was transmitted to a 10-year-old girl in Oregon by a scratch wound inflicted by a domestic cat. The cat probably was infected by contact with infected wild rodents or their fleas. Yersinia pestis was identified in Diamanus montanus fleas collected from an abandoned burrow near the patient's home. Domestic cats may infect humans with Y pestis by inoculation from a scratch.

  5. Plague foci in Viet Nam: zoological and parasitological aspects.

    Science.gov (United States)

    Suntsov, V V; Huong, L T; Suntsova, N I; Gratz, N G

    1997-01-01

    Reported are the results of studies over the period 1989-94 on host-flea complexes in small mammals and their flea ectoparasites in and around a number of human settlements in Viet Nam in which human cases of plague had been found. Collections were also made in savanna and tropical forest areas within a 10-km radius of the settlements. The greatest numbers of small mammals, for the most part Rattus spp., and of the flea ectoparasite Xenopsylla cheopis were found in inhabited areas. X. cheopis was not found on any feral or sylvan mammal further than 0.6 km from settlements. A possible link between wild and commensal mammals may be provided by the flea Lentistivalius klossi, a specific parasite of squirrels and tree-shrews but also found in very small numbers on commensal rats. No zoonotic foci of plague were found in the immediate vicinity of the villages studied and it is most likely that plague persists in a commensal rat-X. cheopis cycle in and around human settlements in Viet Nam.

  6. Identification of Chinese plague foci from long-term epidemiological data.

    Science.gov (United States)

    Ben-Ari, Tamara; Neerinckx, Simon; Agier, Lydiane; Cazelles, Bernard; Xu, Lei; Zhang, Zhibin; Fang, Xiye; Wang, Shuchun; Liu, Qiyong; Stenseth, Nils C

    2012-05-22

    Carrying out statistical analysis over an extensive dataset of human plague reports in Chinese villages from 1772 to 1964, we identified plague endemic territories in China (i.e., plague foci). Analyses rely on (i) a clustering method that groups time series based on their time-frequency resemblances and (ii) an ecological niche model that helps identify plague suitable territories characterized by value ranges for a set of predefined environmental variables. Results from both statistical tools indicate the existence of two disconnected plague territories corresponding to Northern and Southern China. Altogether, at least four well defined independent foci are identified. Their contours compare favorably with field observations. Potential and limitations of inferring plague foci and dynamics using epidemiological data is discussed.

  7. Vaccines for Conservation: Plague, Prairie Dogs & Black-Footed Ferrets as a Case Study.

    Science.gov (United States)

    Salkeld, Daniel J

    2017-09-06

    The endangered black-footed ferret (Mustela nigripes) is affected by plague, caused by Yersinia pestis, both directly, as a cause of mortality, and indirectly, because of the impacts of plague on its prairie dog (Cynomys spp.) prey base. Recent developments in vaccines and vaccine delivery have raised the possibility of plague control in prairie dog populations, thereby protecting ferret populations. A large-scale experimental investigation across the western US shows that sylvatic plague vaccine delivered in oral baits can increase prairie dog survival. In northern Colorado, an examination of the efficacy of insecticides to control fleas and plague vaccine shows that timing and method of plague control is important, with different implications for long-term and large-scale management of Y. pestis delivery. In both cases, the studies show that ambitious field-work and cross-sectoral collaboration can provide potential solutions to difficult issues of wildlife management, conservation and disease ecology.

  8. Identification of Chinese plague foci from long-term epidemiological data

    Science.gov (United States)

    Ben-Ari, Tamara; Neerinckx, Simon; Agier, Lydiane; Cazelles, Bernard; Xu, Lei; Zhang, Zhibin; Fang, Xiye; Wang, Shuchun; Liu, Qiyong; Stenseth, Nils C.

    2012-01-01

    Carrying out statistical analysis over an extensive dataset of human plague reports in Chinese villages from 1772 to 1964, we identified plague endemic territories in China (i.e., plague foci). Analyses rely on (i) a clustering method that groups time series based on their time-frequency resemblances and (ii) an ecological niche model that helps identify plague suitable territories characterized by value ranges for a set of predefined environmental variables. Results from both statistical tools indicate the existence of two disconnected plague territories corresponding to Northern and Southern China. Altogether, at least four well defined independent foci are identified. Their contours compare favorably with field observations. Potential and limitations of inferring plague foci and dynamics using epidemiological data is discussed. PMID:22570501

  9. The use of high-resolution remote sensing for plague surveillance in Kazakhstan

    DEFF Research Database (Denmark)

    Addink, E A; De Jong, S M; Davis, S A

    2010-01-01

    Bubonic plague, caused by the bacteria Yersinia pestis, persists as a public health problem in many parts of the world, including central Kazakhstan. Bubonic plague occurs most often in humans through a flea bite, when a questing flea fails to find a rodent host. For many of the plague foci...... in Kazakhstan the great gerbil is the major host of plague, a social rodent well-adapted to desert environments. Intensive monitoring and prevention of plague in gerbils started in 1947, reducing the number of human cases and mortalities drastically. However, the monitoring is labour-intensive and hence...... expensive and is now under threat due to financial constraints. Previous research showed that the occupancy rate of the burrow systems of the great gerbil is a strong indicator for the probability of a plague outbreak. The burrow systems are around 30 m in diameter with a bare surface. This paper aims...

  10. Identification of duck plague virus by polymerase chain reaction

    Science.gov (United States)

    Hansen, W.R.; Brown, Sean E.; Nashold, S.W.; Knudson, D.L.

    1999-01-01

    A polymerase chain reaction (PCR) assay was developed for detecting duck plague virus. A 765-bp EcoRI fragment cloned from the genome of the duck plague vaccine (DP-VAC) virus was sequenced for PCR primer development. The fragment sequence was found by GenBank alignment searches to be similar to the 3a?? ends of an undefined open reading frame and the gene for DNA polymerase protein in other herpesviruses. Three of four primer sets were found to be specific for the DP-VAC virus and 100% (7/7) of field isolates but did not amplify DNA from inclusion body disease of cranes virus. The specificity of one primer set was tested with genome templates from other avian herpesviruses, including those from a golden eagle, bald eagle, great horned owl, snowy owl, peregrine falcon, prairie falcon, pigeon, psittacine, and chicken (infectious laryngotracheitis), but amplicons were not produced. Hence, this PCR test is highly specific for duck plague virus DNA. Two primer sets were able to detect 1 fg of DNA from the duck plague vaccine strain, equivalent to five genome copies. In addition, the ratio of tissue culture infectious doses to genome copies of duck plague vaccine virus from infected duck embryo cells was determined to be 1:100, making the PCR assay 20 times more sensitive than tissue culture for detecting duck plague virus. The speed, sensitivity, and specificity of this PCR provide a greatly improved diagnostic and research tool for studying the epizootiology of duck plague. /// Se desarroll?? una prueba de reacci??n en cadena por la polimerasa para detectar el virus de la peste del pato. Un fragmento EcoRI de 765 pares de bases clonado del genoma del virus vacunal de la peste del pato fue secuenciado para la obtenci??n de los iniciadores de la prueba de la reacci??n en cadena por la polimerasa. En investigaciones de alineaci??n en el banco de genes ('GenBank') se encontr?? que la secuencia del fragmento era similar a los extremos 3a?? de un marco de lectura abierto

  11. Rodent and flea abundance fail to predict a plague epizootic in black-tailed prairie dogs.

    Science.gov (United States)

    Brinkerhoff, Robert Jory; Collinge, Sharon K; Ray, Chris; Gage, Ken L

    2010-01-01

    Small rodents are purported to be enzootic hosts of Yersinia pestis and may serve as sources of infection to prairie dogs or other epizootic hosts by direct or flea-mediated transmission. Recent research has shown that small rodent species composition and small rodent flea assemblages are influenced by the presence of prairie dogs, with higher relative abundance of both small rodents and fleas at prairie dog colony sites compared to grasslands without prairie dogs. However, it is unclear if increased rodent or flea abundance predisposes prairie dogs to infection with Y. pestis. We tracked rodent and flea occurrence for 3 years at a number of prairie dog colony sites in Boulder County, Colorado, before, during, and after a local plague epizootic to see if high rodent or flea abundance was associated with plague-affected colonies when compared to colonies that escaped infection. We found no difference in preepizootic rodent abundance or flea prevalence or abundance between plague-positive and plague-negative colonies. Further, we saw no significant before-plague/after-plague change in these metrics at either plague-positive or plague-negative sites. We did, however, find that small rodent species assemblages changed in the year following prairie dog die-offs at plague-affected colonies when compared to unaffected colonies. In light of previous research from this system that has shown that landscape features and proximity to recently plagued colonies are significant predictors of plague occurrence in prairie dogs, we suggest that landscape context is more important to local plague occurrence than are characteristics of rodent or flea species assemblages.

  12. Plague vaccines and the molecular basis of immunity against Yersinia pestis.

    Science.gov (United States)

    Quenee, Lauriane E; Schneewind, Olaf

    2009-12-01

    Yersinia pestis is the causative agent of bubonic and pneumonic plague, human diseases with high mortality. Due to the microbe's ability to spread rapidly, plague epidemics present a serious public health threat. A search for prophylactic measures was initially based on historical reports of bubonic plague survivors and their apparent immunity. Due to safety and efficacy concerns, killed whole-cell preparations or live-attenuated plague vaccines are no longer considered in the United States. Vaccine developers have focused on specific subunits of plague bacteria. LcrV, a protein at the tip of type III secretion needles, and F1, the capsular pilus antigen, are both recognized as plague protective antigens. Antibodies against LcrV and F1 interfere with Y. pestis type III injection of host cells. While LcrV is absolutely essential for Y. pestis virulence, expression of F1 is dispensable for plague pathogenesis in small animals, non-human primates and presumably also in humans. Several subunit vaccines, for example rF1+rV (rYP002), rF1V or rV10, are being developed to generate plague protection in humans. Efficacy testing and licensure for human use requires the establishment of correlates for plague immunity.

  13. Nonlinear effect of climate on plague during the third pandemic in China.

    Science.gov (United States)

    Xu, Lei; Liu, Qiyong; Stige, Leif Chr; Ben Ari, Tamara; Fang, Xiye; Chan, Kung-Sik; Wang, Shuchun; Stenseth, Nils Chr; Zhang, Zhibin

    2011-06-21

    Over the years, plague has caused a large number of deaths worldwide and subsequently changed history, not the least during the period of the Black Death. Of the three plague pandemics, the third is believed to have originated in China. Using the spatial and temporal human plague records in China from 1850 to 1964, we investigated the association of human plague intensity (plague cases per year) with proxy data on climate condition (specifically an index for dryness/wetness). Our modeling analysis demonstrates that the responses of plague intensity to dry/wet conditions were different in northern and southern China. In northern China, plague intensity generally increased when wetness increased, for both the current and the previous year, except for low intensity during extremely wet conditions in the current year (reflecting a dome-shaped response to current-year dryness/wetness). In southern China, plague intensity generally decreased when wetness increased, except for high intensity during extremely wet conditions of the current year. These opposite effects are likely related to the different climates and rodent communities in the two parts of China: In northern China (arid climate), rodents are expected to respond positively to high precipitation, whereas in southern China (humid climate), high precipitation is likely to have a negative effect. Our results suggest that associations between human plague intensity and precipitation are nonlinear: positive in dry conditions, but negative in wet conditions.

  14. [The complex plague--reconsiderations of an epidemic from the past].

    Science.gov (United States)

    Moseng, Ole Georg

    2007-12-13

    Speculations have arisen about the black plague in recent years - was it a disease caused by YERSINIA PESTIS: or something else? Extensive outbreaks in India in the 1890s have formed the basis for descriptions of the plague, both for those who believe that the medieval plagues and modern plague were different diseases and for those who claim that the plague has been one and the same disease throughout history. The plague was more or less defined as a disease in the 1890s, and the understanding of its clinical course and dissemination at the time has uncritically been understood as the general model for spreading of the plague. But plague is a many-faceted disease. It has spread to five continents in modern times, through an array of ecosystems and under widely different climatic conditions. It can also be passed on to man, and from one individual to another, in different ways. The biological conditions that prevailed in India have not been relevant for medieval Norway. The preconditions for spreading of plague epidemics of the past in a Nordic climate must therefore have been different. It can only be expected that contemporary descriptions of historic epidemics are different from those in modern times.

  15. Historical Epidemics Cartography Generated by Spatial Analysis: Mapping the Heterogeneity of Three Medieval "Plagues" in Dijon

    National Research Council Canada - National Science Library

    Pierre Galanaud; Anne Galanaud; Patrick Giraudoux

    .... We mapped "plague" deaths during three epidemics of the early 15th century, analyzed spatial distributions by applying the Kulldorff's method, and determined their relationships with the distribution...

  16. [The time course of changes in cell immunological parameters during administration of live dry plague vaccine].

    Science.gov (United States)

    Bogacheva, N V; Darmov, I V; Borisevich, I V; Kriuchkov, A V; Pechenkin, D V

    2009-08-01

    The study of the time course of changes in cell immunological parameters by a magnetic separation technique in human beings during the administration of plague vaccine in relation to the immunological load revealed the higher blood levels of all T lymphocyte subpopulations on day 14 after vaccination. These changes are most typical of a primary vaccinated cohort. The increased frequency of plague vaccine administration and multiple immunizations with live plague, anthrax, and tularemia vaccines produce the time-course of changes in T lymphocyte populations (subpopulations) in response to the regular administration of plague vaccine. A high immunological load in man also promotes a significant reduction in the level of B lymphocytes.

  17. Landscape ecology of plague in the American southwest, September 19-20, 2000, Fort Collins, Colorado

    Science.gov (United States)

    Brand, Christopher J.

    2002-01-01

    During September 19-20, 2000, a workshop titled "Landscape Ecology of Plague in the American Southwest" was held in Fort Collins, Colorado. The workshop was funded by the U.S. Geological Survey (USGS)-Earth Surface Processes Team and sponsored by the USGS National Wildlife Health Center. Forty scientists and natural resource managers and administrators representing 8 federal agencies, 4 state agencies, 6 universities, and other local agencies and nongovernment organizations met to discuss historical and current status of plague in the United States, current activities in plague surveillance, research, and management in wildlife, and research and information needs relative to plague control and management. Eleven individual presentations on plague history, status, and trends; diagnostic technologies; epizootiological studies and observations; and control and management strategies and studies, followed by a panel discussion on the impact of plague on wildlife and ecosystems, led the way to extensive group discussions on important plague-related questions, issues and problems. Workshop attendees participated in identifying important research and information needs relevant to control and management of plague in wildlife, and in the process, established new cooperative and collaborative partnerships and enhanced existing relationships upon which future research and information needs can be met. The proceedings from this workshop are intended to be used by the natural resource managers and researchers from the various participating agencies, research facilities, as well as other stakeholders to aid in the development of future research and information programs and funding initiatives related to both zoonotic and sylvatic plague.

  18. Nonlinear effect of climate on plague during the third pandemic in China

    Science.gov (United States)

    Xu, Lei; Liu, Qiyong; Stige, Leif Chr.; Ben Ari, Tamara; Fang, Xiye; Chan, Kung-Sik; Wang, Shuchun; Stenseth, Nils Chr.; Zhang, Zhibin

    2011-01-01

    Over the years, plague has caused a large number of deaths worldwide and subsequently changed history, not the least during the period of the Black Death. Of the three plague pandemics, the third is believed to have originated in China. Using the spatial and temporal human plague records in China from 1850 to 1964, we investigated the association of human plague intensity (plague cases per year) with proxy data on climate condition (specifically an index for dryness/wetness). Our modeling analysis demonstrates that the responses of plague intensity to dry/wet conditions were different in northern and southern China. In northern China, plague intensity generally increased when wetness increased, for both the current and the previous year, except for low intensity during extremely wet conditions in the current year (reflecting a dome-shaped response to current-year dryness/wetness). In southern China, plague intensity generally decreased when wetness increased, except for high intensity during extremely wet conditions of the current year. These opposite effects are likely related to the different climates and rodent communities in the two parts of China: In northern China (arid climate), rodents are expected to respond positively to high precipitation, whereas in southern China (humid climate), high precipitation is likely to have a negative effect. Our results suggest that associations between human plague intensity and precipitation are nonlinear: positive in dry conditions, but negative in wet conditions. PMID:21646523

  19. Recombinant raccoon pox vaccine protects mice against lethal plague

    Science.gov (United States)

    Osorio, J.E.; Powell, T.D.; Frank, R.S.; Moss, K.; Haanes, E.J.; Smith, S.R.; Rocke, T.E.; Stinchcomb, D.T.

    2003-01-01

    Using a raccoon poxvirus (RCN) expression system, we have developed new recombinant vaccines that can protect mice against lethal plague infection. We tested the effects of a translation enhancer (EMCV-IRES) in combination with a secretory (tPA) signal or secretory (tPA) and membrane anchoring (CHV-gG) signals on in vitro antigen expression of F1 antigen in tissue culture and the induction of antibody responses and protection against Yersinia pestis challenge in mice. The RCN vector successfully expressed the F1 protein of Y. pestis in vitro. In addition, the level of expression was increased by the insertion of the EMCV-IRES and combinations of this and the secretory signal or secretory and anchoring signals. These recombinant viruses generated protective immune responses that resulted in survival of 80% of vaccinated mice upon challenge with Y. pestis. Of the RCN-based vaccines we tested, the RCN-IRES-tPA-YpF1 recombinant construct was the most efficacious. Mice vaccinated with this construct withstood challenge with as many as 1.5 million colony forming units of Y. pestis (7.7??104LD50). Interestingly, vaccination with F1 fused to the anchoring signal (RCN-IRES-tPA-YpF1-gG) elicited significant anti-F1 antibody titers, but failed to protect mice from plague challenge. Our studies demonstrate, in vitro and in vivo, the potential importance of the EMCV-IRES and secretory signals in vaccine design. These molecular tools provide a new approach for improving the efficacy of vaccines. In addition, these novel recombinant vaccines could have human, veterinary, and wildlife applications in the prevention of plague. ?? 2002 Elsevier Science Ltd. All rights reserved.

  20. AFLP genome scan in the black rat (Rattus rattus) from Madagascar: detecting genetic markers undergoing plague-mediated selection.

    Science.gov (United States)

    Tollenaere, C; Duplantier, J-M; Rahalison, L; Ranjalahy, M; Brouat, C

    2011-03-01

    The black rat (Rattus rattus) is the main reservoir of plague (Yersinia pestis infection) in Madagascar's rural zones. Black rats are highly resistant to plague within the plague focus (central highland), whereas they are susceptible where the disease is absent (low altitude zone). To better understand plague wildlife circulation and host evolution in response to a highly virulent pathogen, we attempted to determine genetic markers associated with plague resistance in this species. To this purpose, we combined a population genomics approach and an association study, both performed on 249 AFLP markers, in Malagasy R. rattus. Simulated distributions of genetic differentiation were compared to observed data in four independent pairs, each consisting of one population from the plague focus and one from the plague-free zone. We found 22 loci (9% of 249) with higher differentiation in at least two independent population pairs or with combining P-values over the four pairs significant. Among the 22 outlier loci, 16 presented significant association with plague zone (plague focus vs. plague-free zone). Population genetic structure inferred from outlier loci was structured by plague zone, whereas the neutral loci dataset revealed structure by geography (eastern vs. western populations). A phenotype association study revealed that two of the 22 loci were significantly associated with differentiation between dying and surviving rats following experimental plague challenge. The 22 outlier loci identified in this study may undergo plague selective pressure either directly or more probably indirectly due to hitchhiking with selected loci. © 2010 Blackwell Publishing Ltd.

  1. Relationship between oriental migratory locust plague and soil moisture extracted from MODIS data

    Science.gov (United States)

    Liu, Zhenbo; Shi, Xuezheng; Warner, Eric; Ge, Yunjian; Yu, Dongsheng; Ni, Shaoxiang; Wang, Hongjie

    2008-02-01

    Locust plagues have been the source of some of the most severe natural disasters in human history. Soil moisture content is among the most important of the numerous factors influencing plague onset and severity. This paper describes a study initiated in three pilot locust plague monitoring regions, i.e., Huangzao, Yangguanzhuang, and Tengnan in Huanghua county, Hebei province, China, to examine the impact of soil moisture status on oriental migratory locust [ Locusta migratoria manilensis (L.) Meyen] plague breakout as related to the life cycle, oviposition in autumn, survival in winter, and incubation in summer. Thirty-nine temperature vegetation dryness index (TVDI) data sets, which represent soil moisture content, were extracted from MODIS remote sensing images for two representative time periods: a severe locust plague breakout year (2001-2002) and a slight plague year (2003-2004). TVDI values demonstrated distinctive soil moisture status differences between the 2 years concerned. Soil moisture conditions in the severe plague year were shown to be lower than those in slight plague year. In all three pilot regions, average TVDI value in the severe plague year was 0.07 higher than that in slight plague year, and monthly TVDI values in locust oviposition period (September and October) and incubation period (March, April and May) were higher than their corresponding monthly figures in slight plague year. No remarkable TVDI differences were found in other months during the locust life cycle between the 2 years. TVDI values for September and October (2001), March, April and May (2002) were 0.11, 0.08, 0.16, 0.11 and 0.16 higher than their corresponding monthly figures in 2003-2004 period, respectively.

  2. The plague of Athens: an ancient act of bioterrorism?

    Science.gov (United States)

    Papagrigorakis, Manolis J; Synodinos, Philippos N; Stathi, Angeliki; Skevaki, Chrysanthi L; Zachariadou, Levantia

    2013-09-01

    Recent data implicate Salmonella enterica serovar Typhi as a causative pathogen of the Plague of Athens during the Peloponnesian War (430-426 bc). According to Thucydides, the sudden outbreak of the disease may link to poisoning of the water reservoirs by the Spartans. The siege of a city was aimed at exhausting the supplies of a population, which often led to the outbreak and spread of epidemics. Poisoning of the water reservoirs of a besieged city as an act of bioterrorism would probably shorten the necessary time for such conditions to appear.

  3. Plague foci in Viet Nam: zoological and parasitological aspects.

    OpenAIRE

    Suntsov, V. V.; Huong, L. T.; Suntsova, N. I.; Gratz, N. G.

    1997-01-01

    Reported are the results of studies over the period 1989-94 on host-flea complexes in small mammals and their flea ectoparasites in and around a number of human settlements in Viet Nam in which human cases of plague had been found. Collections were also made in savanna and tropical forest areas within a 10-km radius of the settlements. The greatest numbers of small mammals, for the most part Rattus spp., and of the flea ectoparasite Xenopsylla cheopis were found in inhabited areas. X. cheopis...

  4. Yersinia pestis endowed with increased cytotoxicity is avirulent in a bubonic plague model and induces rapid protection against pneumonic plague.

    Directory of Open Access Journals (Sweden)

    Ayelet Zauberman

    Full Text Available An important virulence strategy evolved by bacterial pathogens to overcome host defenses is the modulation of host cell death. Previous observations have indicated that Yersinia pestis, the causative agent of plague disease, exhibits restricted capacity to induce cell death in macrophages due to ineffective translocation of the type III secretion effector YopJ, as opposed to the readily translocated YopP, the YopJ homologue of the enteropathogen Yersinia enterocolitica Oratio8. This led us to suggest that reduced cytotoxic potency may allow pathogen propagation within a shielded niche, leading to increased virulence. To test the relationship between cytotoxic potential and virulence, we replaced Y. pestis YopJ with YopP. The YopP-expressing Y. pestis strain exhibited high cytotoxic activity against macrophages in vitro. Following subcutaneous infection, this strain had reduced ability to colonize internal organs, was unable to induce septicemia and exhibited at least a 10(7-fold reduction in virulence. Yet, upon intravenous or intranasal infection, it was still as virulent as the wild-type strain. The subcutaneous administration of the cytotoxic Y. pestis strain appears to activate a rapid and potent systemic, CTL-independent, immunoprotective response, allowing the organism to overcome simultaneous coinfection with 10,000 LD(50 of virulent Y. pestis. Moreover, three days after subcutaneous administration of this strain, animals were also protected against septicemic or primary pneumonic plague. Our findings indicate that an inverse relationship exists between the cytotoxic potential of Y. pestis and its virulence following subcutaneous infection. This appears to be associated with the ability of the engineered cytotoxic Y. pestis strain to induce very rapid, effective and long-lasting protection against bubonic and pneumonic plague. These observations have novel implications for the development of vaccines/therapies against Y. pestis and shed

  5. Yersinia pestis endowed with increased cytotoxicity is avirulent in a bubonic plague model and induces rapid protection against pneumonic plague.

    Science.gov (United States)

    Zauberman, Ayelet; Tidhar, Avital; Levy, Yinon; Bar-Haim, Erez; Halperin, Gideon; Flashner, Yehuda; Cohen, Sara; Shafferman, Avigdor; Mamroud, Emanuelle

    2009-06-16

    An important virulence strategy evolved by bacterial pathogens to overcome host defenses is the modulation of host cell death. Previous observations have indicated that Yersinia pestis, the causative agent of plague disease, exhibits restricted capacity to induce cell death in macrophages due to ineffective translocation of the type III secretion effector YopJ, as opposed to the readily translocated YopP, the YopJ homologue of the enteropathogen Yersinia enterocolitica Oratio8. This led us to suggest that reduced cytotoxic potency may allow pathogen propagation within a shielded niche, leading to increased virulence. To test the relationship between cytotoxic potential and virulence, we replaced Y. pestis YopJ with YopP. The YopP-expressing Y. pestis strain exhibited high cytotoxic activity against macrophages in vitro. Following subcutaneous infection, this strain had reduced ability to colonize internal organs, was unable to induce septicemia and exhibited at least a 10(7)-fold reduction in virulence. Yet, upon intravenous or intranasal infection, it was still as virulent as the wild-type strain. The subcutaneous administration of the cytotoxic Y. pestis strain appears to activate a rapid and potent systemic, CTL-independent, immunoprotective response, allowing the organism to overcome simultaneous coinfection with 10,000 LD(50) of virulent Y. pestis. Moreover, three days after subcutaneous administration of this strain, animals were also protected against septicemic or primary pneumonic plague. Our findings indicate that an inverse relationship exists between the cytotoxic potential of Y. pestis and its virulence following subcutaneous infection. This appears to be associated with the ability of the engineered cytotoxic Y. pestis strain to induce very rapid, effective and long-lasting protection against bubonic and pneumonic plague. These observations have novel implications for the development of vaccines/therapies against Y. pestis and shed new light on the

  6. Enzootic Plague Reduces Black-Footed Ferret (Mustela nigripes) Survival in Montana

    Science.gov (United States)

    2010-01-01

    of plague. Clin Microbiol Rev 1997; 10:35–66. Poland, JD, Barnes, AM. Plague. In: Steele, JH, ed. CRC Handbook Series in Zoonoses . Boca Raton, FL...Quan, TJ, Barnes, AM, Polland, JD. Yersiniosis. In: Barlows, A, Hausler, WJ, Jr., eds. Diagnostic Procedures for Bacterial, Mycotic and Parasitic

  7. Population genetic structure of the prairie dog flea and plague vector, Oropsylla hirsuta.

    Science.gov (United States)

    Brinkerhoff, R Jory; Martin, Andrew P; Jones, Ryan T; Collinge, Sharon K

    2011-01-01

    Oropsylla hirsuta is the primary flea of the black-tailed prairie dog and is a vector of the plague bacterium, Yersinia pestis. We examined the population genetic structure of O. hirsuta fleas collected from 11 prairie dog colonies, 7 of which had experienced a plague-associated die-off in 1994. In a sample of 332 O. hirsuta collected from 226 host individuals, we detected 24 unique haplotype sequences in a 480 nucleotide segment of the cytochrome oxidase II gene. We found significant overall population structure but we did not detect a signal of isolation by distance, suggesting that O. hirsuta may be able to disperse relatively quickly at the scale of this study. All 7 colonies that were recently decimated by plague showed signs of recent population expansion, whereas 3 of the 4 plague-negative colonies showed haplotype patterns consistent with stable populations. These results suggest that O. hirsuta populations are affected by plague-induced prairie dog die-offs and that flea dispersal among prairie dog colonies may not be dependent exclusively on dispersal of prairie dogs. Re-colonization following plague events from plague-free refugia may allow for rapid flea population expansion following plague epizootics.

  8. A plague epizootic in the black-tailed prairie dog (Cynomys ludovicianus).

    Science.gov (United States)

    Pauli, Jonathan N; Buskirk, Steven W; Williams, Elizabeth S; Edwards, William H

    2006-01-01

    Plague is the primary cause for the rangewide decline in prairie dog (Cynomys spp.) distribution and abundance, yet our knowledge of plague dynamics in prairie dog populations is limited. Our understanding of the effects of plague on the most widespread species, the black-tailed prairie dog (C. ludovicianus), is particularly weak. During a study on the population biology of black-tailed prairie dogs in Wyoming, USA, plague was detected in a colony under intensive monitoring, providing a unique opportunity to quantify various consequences of plague. The epizootic reduced juvenile abundance by 96% and adult abundance by 95%. Of the survivors, eight of nine adults and one of eight juveniles developed antibodies to Yersinia pestis. Demographic groups appeared equally susceptible to infection, and age structure was unaffected. Survivors occupied three small coteries and exhibited improved body condition, but increased flea infestation compared to a neighboring, uninfected colony. Black-tailed prairie dogs are capable of surviving a plague epizootic and reorganizing into apparently functional coteries. Surviving prairie dogs may be critical in the repopulation of plague-decimated colonies and, ultimately, the evolution of plague resistance.

  9. Spread of plague among black-tailed prairie dogs is associated with colony spatial characteristics

    Science.gov (United States)

    Johnson, T.L.; Cully, J.F.; Collinge, S.K.; Ray, C.; Frey, C.M.; Sandercock, B.K.

    2011-01-01

    Sylvatic plague (Yersinia pestis) is an exotic pathogen that is highly virulent in black-tailed prairie dogs (Cynomys ludovicianus) and causes widespread colony losses and individual mortality rates >95%. We investigated colony spatial characteristics that may influence inter-colony transmission of plague at 3 prairie dog colony complexes in the Great Plains. The 4 spatial characteristics we considered include: colony size, Euclidean distance to nearest neighboring colony, colony proximity index, and distance to nearest drainage (dispersal) corridor. We used multi-state mark-recapture models to determine the relationship between these colony characteristics and probability of plague transmission among prairie dog colonies. Annual mapping of colonies and mark-recapture analyses of disease dynamics in natural colonies led to 4 main results: 1) plague outbreaks exhibited high spatial and temporal variation, 2) the site of initiation of epizootic plague may have substantially influenced the subsequent inter-colony spread of plague, 3) the long-term effect of plague on individual colonies differed among sites because of how individuals and colonies were distributed, and 4) colony spatial characteristics were related to the probability of infection at all sites although the relative importance and direction of relationships varied among sites. Our findings suggest that conventional prairie dog conservation management strategies, including promoting large, highly connected colonies, may need to be altered in the presence of plague. ?? 2011 The Wildlife Society.

  10. Assessing plague risk and presence through surveys of small mammal flea communities

    Science.gov (United States)

    M. M. Friggens; P. L. Ford; R. R. Parmenter; M. Boyden; K. Gage

    2011-01-01

    Plague, caused by the bacterium Yersinia pestis, remains a threat to human and wildlife populations in the Western United States (Gage and Kosoy 2005). Several rodent species have been implicated as important maintenance hosts in the U.S., including Peromyscus maniculatus and Dipodomys spp. Fleas are a critical component of plague foci (Gage and Kosoy 2005)....

  11. Microevolution and history of the plague bacillus, Yersinia pestis.

    Science.gov (United States)

    Achtman, Mark; Morelli, Giovanna; Zhu, Peixuan; Wirth, Thierry; Diehl, Ines; Kusecek, Barica; Vogler, Amy J; Wagner, David M; Allender, Christopher J; Easterday, W Ryan; Chenal-Francisque, Viviane; Worsham, Patricia; Thomson, Nicholas R; Parkhill, Julian; Lindler, Luther E; Carniel, Elisabeth; Keim, Paul

    2004-12-21

    The association of historical plague pandemics with Yersinia pestis remains controversial, partly because the evolutionary history of this largely monomorphic bacterium was unknown. The microevolution of Y. pestis was therefore investigated by three different multilocus molecular methods, targeting genomewide synonymous SNPs, variation in number of tandem repeats, and insertion of IS100 insertion elements. Eight populations were recognized by the three methods, and we propose an evolutionary tree for these populations, rooted on Yersinia pseudotuberculosis. The tree invokes microevolution over millennia, during which enzootic pestoides isolates evolved. This initial phase was followed by a binary split 6,500 years ago, which led to populations that are more frequently associated with human disease. These populations do not correspond directly to classical biovars that are based on phenotypic properties. Thus, we recommend that henceforth groupings should be based on molecular signatures. The age of Y. pestis inferred here is compatible with the dates of historical pandemic plague. However, it is premature to infer an association between any modern molecular grouping and a particular pandemic wave that occurred before the 20th century.

  12. Typing methods for the plague pathogen, Yersinia pestis.

    Science.gov (United States)

    Lindler, Luther E

    2009-01-01

    Phenotypic and genotypic methodologies have been used to differentiate the etiological agent of plague, Yersinia pestis. Historically, phenotypic methods were used to place isolates into one of three biovars based on nitrate reduction and glycerol fermentation. Classification of Y. pestis into genetic subtypes is problematic due to the relative monomorphic nature of the pathogen. Resolution into groups is dependent on the number and types of loci used in the analysis. The last 5-10 years of research and analysis in the field of Y. pestis genotyping have resulted in a recognition by Western scientists that two basic types of Y. pestis exist. One type, considered to be classic strains that are able to cause human plague transmitted by the normal flea vector, is termed epidemic strains. The other type does not typically cause human infections by normal routes of infection, but is virulent for rodents and is termed endemic strains. Previous classification schemes used outside the Western hemisphere referred to these latter strains as Pestoides varieties of Y. pestis. Recent molecular analysis has definitely shown that both endemic and epidemic strains arose independently from a common Yersinia pseudotuberculosis ancestor. Currently, 11 major groups of Y. pestis are defined globally.

  13. Earthquakes and plague during Byzantine times: can lessons from the past improve epidemic preparedness.

    Science.gov (United States)

    Tsiamis, Costas; Poulakou-Rebelakou, Effie; Marketos, Spyros

    2013-01-01

    Natural disasters have always been followed by a fear of infectious diseases. This raised historical debate about one of the most feared scenarios: the outbreak of bubonic plague caused by Yersinia pestis. One such event was recorded in the Indian state Maharashtra in 1994 after an earthquake. In multidisciplinary historical approach to the evolution of plague, many experts ignore the possibility of natural foci and their activation. This article presents historical records from the Byzantine Empire about outbreaks of the Plague of Justinian occurring months or even up to a year after high-magnitude earthquakes. Historical records of plague outbreaks can be used to document existence of natural foci all over the world. Knowledge of these historical records and the contemporary examples of plague support the assumption that, in terms of organising humanitarian aid, poor monitoring of natural foci could lead to unpredictable epidemiological consequences after high-magnitude earthquakes.

  14. East to West or West to East: Plague Spread after the Black Death

    Directory of Open Access Journals (Sweden)

    Yujun Cui

    2016-07-01

    Full Text Available The Black Death, one of the most destructive pandemics in human history, has claimed millions of lives and considerably influenced human civilization. Following the Black Death, plague outbreaks in Europe lasted for several hundred years until late the 18th century. It is generally presumed that the Black Death was caused by Yersinia pestis (Y. pestis and spread from China to Europe in one or more waves. However, because of the lack of etiological research during the medieval period and absence of a natural plague focus in Europe today, the causative agent of this pandemic and its transmission has led to long-term debate among researchers. Thus, several questions remain including whether Y. pestis actually caused the Black Death, whether a natural plague focus existed in medieval Europe and led to post-Black Death plague outbreaks, and whether the Europe plague focus played a role in the spread and evolution of Y. pestis.

  15. [Historical and biological approaches to the study of Modern Age French plague mass burials].

    Science.gov (United States)

    Bianuccii, Raffaella; Tzortzis, Stéfan; Fornaciari, Gino; Signoli, Michel

    2010-01-01

    The "Black Death" and subsequent epidemics from 1346 to the early 18th century spread from the Caspian Sea all over Europe six hundred years after the outbreak of the Justinian plague (541-767 AD). Plague has been one of the most devastating infectious diseases that affected the humankind and has caused approximately 200 million human deaths historically. Here we describe the different approaches adopted in the study of several French putative plague mass burials dating to the Modern Age (16th-18th centuries). Through complementation of historical, archaeological and paleobiological data, ample knowledge of both the causes that favoured the spread of the Medieval plague in cities, towns and small villages and of the modification of the customary funerary practices in urban and rural areas due to plague are gained.

  16. Climate-driven introduction of the Black Death and successive plague reintroductions into Europe.

    Science.gov (United States)

    Schmid, Boris V; Büntgen, Ulf; Easterday, W Ryan; Ginzler, Christian; Walløe, Lars; Bramanti, Barbara; Stenseth, Nils Chr

    2015-03-10

    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.

  17. Climate-driven introduction of the Black Death and successive plague reintroductions into Europe

    Science.gov (United States)

    Büntgen, Ulf; Easterday, W. Ryan; Ginzler, Christian; Walløe, Lars; Bramanti, Barbara; Stenseth, Nils Chr.

    2015-01-01

    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. PMID:25713390

  18. Eighteenth century Yersinia pestis genomes reveal the long-term persistence of an historical plague focus.

    Science.gov (United States)

    Bos, Kirsten I; Herbig, Alexander; Sahl, Jason; Waglechner, Nicholas; Fourment, Mathieu; Forrest, Stephen A; Klunk, Jennifer; Schuenemann, Verena J; Poinar, Debi; Kuch, Melanie; Golding, G Brian; Dutour, Olivier; Keim, Paul; Wagner, David M; Holmes, Edward C; Krause, Johannes; Poinar, Hendrik N

    2016-01-21

    The 14th-18th century pandemic of Yersinia pestis caused devastating disease outbreaks in Europe for almost 400 years. The reasons for plague's persistence and abrupt disappearance in Europe are poorly understood, but could have been due to either the presence of now-extinct plague foci in Europe itself, or successive disease introductions from other locations. Here we present five Y. pestis genomes from one of the last European outbreaks of plague, from 1722 in Marseille, France. The lineage identified has not been found in any extant Y. pestis foci sampled to date, and has its ancestry in strains obtained from victims of the 14th century Black Death. These data suggest the existence of a previously uncharacterized historical plague focus that persisted for at least three centuries. We propose that this disease source may have been responsible for the many resurgences of plague in Europe following the Black Death.

  19. The Measures for Plague of Locust and the Views about Plague in Song Dynasty%宋代蝗灾应对和灾异观之变化

    Institute of Scientific and Technical Information of China (English)

    赵杏根

    2012-01-01

    “灾异说”认为,灾异乃是社会政治问题所致,当局应以改革社会政治应对。主流社会长期以此应对灾异,故对蝗灾也不采取捕杀措施。在唐代姚崇以下以捕杀应对蝗灾的基础上,宋人以全面捕杀为主要手段应对蝗灾,在实践上突破了“灾异说”。与此相应,对“灾异说”,宋代的思想精英们从前人的笃信发展为质疑,乃至彻底抛弃,客观、理性地应对蝗灾等灾异。%In the theory about plague before, a plague was resulted in the relevant social and political errors, and the only mea- sure against the plague was to correct the errors. The authorities had been done against the plagues according to the theory in the period of more than 1000 years, and not killed the locusts in the plagues of locust, just with some exceptions. In Song, killing lo- custs was the popular measure against the plagues of locust, people knew a lot about locust, and some gentlemen began to sus- pect the theory about plague that had been very popular since Hun Dynasty, and even abandoned it at last.

  20. Origin of the old testament plagues: explications and implications.

    Science.gov (United States)

    Ehrenkranz, N Joel; Sampson, Deborah A

    2008-03-01

    Analyses of past disasters may supply insights to mitigate the impact of recurrences. In this context, we offer a unifying causative theory of Old Testament plagues, which has present day public health implications. We propose the root cause to have been an aberrant El Niño-Southern Oscillation teleconnection that brought unseasonable and progressive climate warming along the ancient Mediterranean littoral, including the coast of biblical Egypt, which, in turn, initiated the serial catastrophes of biblical sequence - in particular arthropod-borne and arthropod-caused diseases. Located beyond the boundary of focal climate change, inland Goshen would not have been similarly affected. Implicit in this analysis is a framework to consider a possibility of present day recurrence of similar catastrophes and their impact upon essential public services.

  1. The Effect of Seasonal Weather Variation on the Dynamics of the Plague Disease

    Directory of Open Access Journals (Sweden)

    Rigobert C. Ngeleja

    2017-01-01

    Full Text Available Plague is a historic disease which is also known to be the most devastating disease that ever occurred in human history, caused by gram-negative bacteria known as Yersinia pestis. The disease is mostly affected by variations of weather conditions as it disturbs the normal behavior of main plague disease transmission agents, namely, human beings, rodents, fleas, and pathogens, in the environment. This in turn changes the way they interact with each other and ultimately leads to a periodic transmission of plague disease. In this paper, we formulate a periodic epidemic model system by incorporating seasonal transmission rate in order to study the effect of seasonal weather variation on the dynamics of plague disease. We compute the basic reproduction number of a proposed model. We then use numerical simulation to illustrate the effect of different weather dependent parameters on the basic reproduction number. We are able to deduce that infection rate, progression rates from primary forms of plague disease to more severe forms of plague disease, and the infectious flea abundance affect, to a large extent, the number of bubonic, septicemic, and pneumonic plague infective agents. We recommend that it is more reasonable to consider these factors that have been shown to have a significant effect on RT for effective control strategies.

  2. Characterization of the rat pneumonic plague model: infection kinetics following aerosolization of Yersinia pestis CO92.

    Science.gov (United States)

    Agar, Stacy L; Sha, Jian; Foltz, Sheri M; Erova, Tatiana E; Walberg, Kristin G; Baze, Wallace B; Suarez, Giovanni; Peterson, Johnny W; Chopra, Ashok K

    2009-02-01

    Yersinia pestis, the causative agent of human bubonic and pneumonic plague, is spread during natural infection by the fleas of rodents. Historically associated with infected rat fleas, studies on the kinetics of infection in rats are surprisingly few, and these reports have focused mainly on bubonic plague. Although the natural route of primary infection results in bubonic plague in humans, it is commonly thought that aerosolized Y. pestis will be utilized during a biowarfare attack. Accordingly, based on our previous characterization of the mouse model of pneumonic plague, we sought to examine the progression of infection in rats exposed in a whole-body Madison chamber to aerosolized Y. pestis CO92. Following an 8.6 LD(50) dose of Y. pestis, injury was apparent in the rat tissues based on histopathology, and chemokines and cytokines rose above control levels (1h post infection [p.i.]) in the sera and organ homogenates over a 72-h infection period. Bacteria disseminated from the lungs to peripheral organs, with the largest increases in the spleen, followed by the liver and blood at 72h p.i. compared to the 1h controls. Importantly, rats were as sensitive to pneumonic plague as mice, having a similar LD(50) dose by the intranasal and aerosolized routes. Further, we showed direct transmission of plague bacteria from infected to uninfected rats. Taken together, the data allowed us to characterize for the first time a rat pneumonic plague model following aerosolization of Y. pestis.

  3. Burrow Dusting or Oral Vaccination Prevents Plague-Associated Prairie Dog Colony Collapse.

    Science.gov (United States)

    Tripp, Daniel W; Rocke, Tonie E; Runge, Jonathan P; Abbott, Rachel C; Miller, Michael W

    2017-06-22

    Plague impacts prairie dogs (Cynomys spp.), the endangered black-footed ferret (Mustela nigripes) and other sensitive wildlife species. We compared efficacy of prophylactic treatments (burrow dusting with deltamethrin or oral vaccination with recombinant "sylvatic plague vaccine" [RCN-F1/V307]) to placebo treatment in black-tailed prairie dog (C. ludovicianus) colonies. Between 2013 and 2015, we measured prairie dog apparent survival, burrow activity and flea abundance on triplicate plots ("blocks") receiving dust, vaccine or placebo treatment. Epizootic plague affected all three blocks but emerged asynchronously. Dust plots had fewer fleas per burrow (P plague emerged. Patterns in corresponding dust and vaccine plots were less consistent and appeared strongly influenced by timing of treatment applications relative to plague emergence. Deltamethrin or oral vaccination enhanced apparent survival within two blocks. Applying insecticide or vaccine prior to epizootic emergence blunted effects of plague on prairie dog survival and abundance, thereby preventing colony collapse. Successful plague mitigation will likely entail strategic combined uses of burrow dusting and oral vaccination within large colonies or colony complexes.

  4. Travel history key to picking up on signs of bubonic plague.

    Science.gov (United States)

    2015-11-01

    Health officials note an uptick in cases of bubonic plague in the United States this year, with at least 12 reported human cases reported since April 1. The CDC notes that healthcare providers should consider plague in patients who have traveled to plague-endemic areas and exhibit fever, headache, chills, weakness, and one or more swollen or tender and painful lymph nodes, referred to as buboes. Officials note that the disease rarely passes from person to person, but that this is a concern with patients who have developed the pneumonic form of the disease. Health officials note that in recent years there has been an average of seven cases of human plague each year in the United States, and that most of these cases are the bubonic form of the illness. Four patients confirmed to have plague this year have died, including the most recent case, a Utah man in his 70s. Most cases of plague in the United States occur in two regions. The first includes northern New Mexico, northern Arizona, and southern Colorado, and the second includes California, southern Oregon, and far western Nevada. When plague is suspected, treatment with antibiotics should begin immediately.

  5. Influence of human activity patterns on epidemiology of plague in Western Usambara Mountains, Tanzania.

    Science.gov (United States)

    Hubeau, Marianne; Gulinck, Hubert; Kimaro, Didas N; Hieronimo, Proches; Meliyo, Joel

    2014-07-01

    Human plague has been a recurring public health threat in some villages in the Western Usambara Mountains, Tanzania, in the period between 1980 and 2004. Despite intensive past biological and medical research, the reasons for the plague outbreaks in the same set of villages remain unknown. Plague research needs to broaden its scope and formulate new hypotheses. This study was carried out to establish relationships between the nature and the spatial extent of selected human activities on one hand, and the reported plague cases on the other hand. Three outdoor activities namely, fetching water, collecting firewood and going to the market, were selected. Through enquiries the activity patterns related to these activities were mapped in 14 villages. Standard deviation ellipses represent the extent of action spaces. Over 130 activity types were identified and listed. Of these, fetching water, collecting firewood and going to the market were used for further analysis. The results indicate a significant correlation between the plague frequency and the size of these action spaces. Different characteristics of land use and related human activities were correlated with the plague frequency at village and hamlet levels. Significant relationships were found between plague frequency and specific sources of firewood and water, and specific market places.

  6. Burrow dusting or oral vaccination prevents plague-associated prairie dog colony collapse

    Science.gov (United States)

    Tripp, Daniel W.; Rocke, Tonie E.; Runge, Jonathan P.; Abbott, Rachel C.; Miller, Michael W.

    2017-01-01

    Plague impacts prairie dogs (Cynomys spp.), the endangered black-footed ferret (Mustela nigripes) and other sensitive wildlife species. We compared efficacy of prophylactic treatments (burrow dusting with deltamethrin or oral vaccination with recombinant “sylvatic plague vaccine” [RCN-F1/V307]) to placebo treatment in black-tailed prairie dog (C. ludovicianus) colonies. Between 2013 and 2015, we measured prairie dog apparent survival, burrow activity and flea abundance on triplicate plots (“blocks”) receiving dust, vaccine or placebo treatment. Epizootic plague affected all three blocks but emerged asynchronously. Dust plots had fewer fleas per burrow (P plague emerged. Patterns in corresponding dust and vaccine plots were less consistent and appeared strongly influenced by timing of treatment applications relative to plague emergence. Deltamethrin or oral vaccination enhanced apparent survival within two blocks. Applying insecticide or vaccine prior to epizootic emergence blunted effects of plague on prairie dog survival and abundance, thereby preventing colony collapse. Successful plague mitigation will likely entail strategic combined uses of burrow dusting and oral vaccination within large colonies or colony complexes.

  7. Bubonic plague: a metapopulation model of a zoonosis.

    Science.gov (United States)

    Keeling, M J; Gilligan, C A

    2000-01-01

    Bubonic plague (Yersinia pestis) is generally thought of as a historical disease; however, it is still responsible for around 1000-3000 deaths each year worldwide. This paper expands the analysis of a model for bubonic plague that encompasses the disease dynamics in rat, flea and human populations. Some key variables of the deterministic model, including the force of infection to humans, are shown to be robust to changes in the basic parameters, although variation in the flea searching efficiency, and the movement rates of rats and fleas will be considered throughout the paper. The stochastic behaviour of the corresponding metapopulation model is discussed, with attention focused on the dynamics of rats and the force of infection at the local spatial scale. Short-lived local epidemics in rats govern the invasion of the disease and produce an irregular pattern of human cases similar to those observed. However, the endemic behaviour in a few rat subpopulations allows the disease to persist for many years. This spatial stochastic model is also used to identify the criteria for the spread to human populations in terms of the rat density. Finally, the full stochastic model is reduced to the form of a probabilistic cellular automaton, which allows the analysis of a large number of replicated epidemics in large populations. This simplified model enables us to analyse the spatial properties of rat epidemics and the effects of movement rates, and also to test whether the emergent metapopulation behaviour is a property of the local dynamics rather than the precise details of the model. PMID:11413636

  8. A bibliography of literature pertaining to plague (Yersinia pestis)

    Science.gov (United States)

    Ellison, Laura E.; Frank, Megan K. Eberhardt

    2011-01-01

    Plague is an acute and often fatal zoonotic disease caused by the bacterium Yersinia pestis. Y. pestis mainly cycles between small mammals and their fleas; however, it has the potential to infect humans and frequently causes fatalities if left untreated. It is often considered a disease of the past; however, since the late 1800s, plagueis geographic range has expanded greatly, posing new threats in previously unaffected regions of the world, including the Western United States. A literature search was conducted using Internet resources and databases. The keywords chosen for the searches included plague, Yersinia pestis, management, control, wildlife, prairie dogs, fleas, North America, and mammals. Keywords were used alone or in combination with the other terms. Although this search pertains mostly to North America, citations were included from the international research community, as well. Databases and search engines used included Google (http://www.google.com), Google Scholar (http://scholar.google.com), SciVerse Scopus (http://www.scopus.com), ISI Web of Knowledge (http://apps.isiknowledge.com), and the USGS Library's Digital Desktop (http://library.usgs.gov). The literature-cited sections of manuscripts obtained from keyword searches were cross-referenced to identify additional citations or gray literature that was missed by the Internet search engines. This Open-File Report, published as an Internet-accessible bibliography, is intended to be periodically updated with new citations or older references that may have been missed during this compilation. Hence, the authors would be grateful to receive notice of any new or old papers that the audience (users) think need to be included.

  9. [PLAGUE IN PALERMO IN 1575 AND SOCIAL CONTROL].

    Science.gov (United States)

    Malta, Renato; Salerno, Alfredo

    2015-01-01

    The work moves from the low mortality of the plague of Palermo in 1575 - 1576 in comparison to similar outbreaks and contemporary analysis of the activity of Ingrassia, a man that the city government had wanted at his side. The extraordinary health interventions, including those to favor of the predisposition of health building to isolation, gears for a more wide-ranging than the traditional one. The isolation adopted by Ingrassia wasn't a novelty because it was already in use half a century earlier, as the Previdelli wrote. We assume that the population in crisis, hungry and out of work for the huge military expenditure of king Philip II, would have prompted the City government to use the outbreak for the purposes of . At the same goal always answered in the sixteenth century the establishment of the parish, created to divide the territory in order to guide and control the practice of the faith of the people. Ingrassia, a man next to political power, which in turn welded with the spiritual power in order to implement the Catholic Counter-Reformation, justified the coercive initiatives towards the population. The practice of medicine, as still happens today, is affected by the conditions of the policy, raising one of the fundamental principles of bioethics, the question ofthe independence ofthe doctor: a physician divided by the duty to represent the legitimate interests of the patient and those of political power, perhaps not always shared. It is a new interpretation of the activity of Ingrassia and his results than the plague.

  10. The trophic responses of two different rodent–vector–plague systems to climate change

    Science.gov (United States)

    Xu, Lei; Schmid, Boris V.; Liu, Jun; Si, Xiaoyan; Stenseth, Nils Chr.; Zhang, Zhibin

    2015-01-01

    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. PMID:25540277

  11. The climatic context of major plague outbreaks in late medieval England

    Science.gov (United States)

    Pribyl, Kathleen

    2017-04-01

    The climatological triggers of major plague outbreaks in late medieval and early modern Europe remain unclear; recent studies have been inconclusive. Plague is primarily a rodent disease and due to the involvement of rodent hosts and insect vectors, the epidemiology of plague is complicated, but research on outbreaks in the Third Pandemic, which began in the late nineteenth century, has shown that in central and eastern Asia plague is linked to specific meteorological conditions. The disease adapts to a varied spectrum of ecological and climatological settings, which influence the development of plague waves, and due to Europe's geographical diversity, this paper focuses on one region, England, in its search for meteorological parameters contributing to plague outbreaks. The study period of this paper is defined by the arrival of Yersinia pestis in the British Isles in 1348 and the end of the fifteenth century. During this time, England's population dynamics were mortality-driven due to recurrent epidemic disease; and public health measures, such as quarantining, had not yet been introduced, hence the influence of social factors on the formation of major plague waves was very limited. The geographical and temporal focus of this study allows for the combination of the series of English major plague outbreaks, verified in the original texts, with the high-quality climate reconstructions based on both documentary sources and proxy data available for this region. The detailed analysis of the mechanisms contributing to English plague waves presented in this paper, reveals a complex interplay of time-lag responses and concurrent conditions involving temperature and precipitation parameters.

  12. The trophic responses of two different rodent-vector-plague systems to climate change.

    Science.gov (United States)

    Xu, Lei; Schmid, Boris V; Liu, Jun; Si, Xiaoyan; Stenseth, Nils Chr; Zhang, Zhibin

    2015-02-07

    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. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  13. Landscape structure and plague occurrence in black-tailed prairie dogs on grasslands of the western USA

    Science.gov (United States)

    Collinge, S.K.; Johnson, W.C.; Ray, C.; Matchett, R.; Grensten, J.; Cully, J.F.; Gage, K.L.; Kosoy, M.Y.; Loye, J.E.; Martin, A.P.

    2005-01-01

    Landscape structure influences the abundance and distribution of many species, including pathogens that cause infectious diseases. Black-tailed prairie dogs in the western USA have declined precipitously over the past 100 years, most recently due to grassland conversion and their susceptibility to sylvatic plague. We assembled and analyzed two long-term data sets on plague occurrence in black-tailed prairie dogs to explore the hypotheses that plague occurrence is associated with colony characteristics and landscape context. Our two study areas (Boulder County, Colorado, and Phillips County, Montana) differed markedly in degree of urbanization and other landscape characteristics. In both study areas, we found associations between plague occurrence and landscape and colony characteristics such as the amount of roads, streams and lakes surrounding a prairie dog colony, the area covered by the colony and its neighbors, and the distance to the nearest plague-positive colony. Logistic regression models were similar between the two study areas, with the best models predicting positive effects of proximity to plague-positive colonies and negative effects of road, stream and lake cover on plague occurrence. Taken together, these results suggest that roads, streams and lakes may serve as barriers to plague in black-tailed prairie dog colonies by affecting movement of or habitat quality for plague hosts or for fleas that serve as vectors for the pathogen. The similarity in plague correlates between urban and rural study areas suggests that the correlates of plague are not altered by uniquely urban stressors. ?? Springer 2005.

  14. Role of the Yersinia pestis yersiniabactin iron acquisition system in the incidence of flea-borne plague.

    Science.gov (United States)

    Sebbane, Florent; Jarrett, Clayton; Gardner, Donald; Long, Daniel; Hinnebusch, B Joseph

    2010-12-17

    Plague is a flea-borne zoonosis caused by the bacterium Yersinia pestis. Y. pestis mutants lacking the yersiniabactin (Ybt) siderophore-based iron transport system are avirulent when inoculated intradermally but fully virulent when inoculated intravenously in mice. Presumably, Ybt is required to provide sufficient iron at the peripheral injection site, suggesting that Ybt would be an essential virulence factor for flea-borne plague. Here, using a flea-to-mouse transmission model, we show that a Y. pestis strain lacking the Ybt system causes fatal plague at low incidence when transmitted by fleas. Bacteriology and histology analyses revealed that a Ybt-negative strain caused only primary septicemic plague and atypical bubonic plague instead of the typical bubonic form of disease. The results provide new evidence that primary septicemic plague is a distinct clinical entity and suggest that unusual forms of plague may be caused by atypical Y. pestis strains.

  15. Role of the Yersinia pestis yersiniabactin iron acquisition system in the incidence of flea-borne plague.

    Directory of Open Access Journals (Sweden)

    Florent Sebbane

    Full Text Available Plague is a flea-borne zoonosis caused by the bacterium Yersinia pestis. Y. pestis mutants lacking the yersiniabactin (Ybt siderophore-based iron transport system are avirulent when inoculated intradermally but fully virulent when inoculated intravenously in mice. Presumably, Ybt is required to provide sufficient iron at the peripheral injection site, suggesting that Ybt would be an essential virulence factor for flea-borne plague. Here, using a flea-to-mouse transmission model, we show that a Y. pestis strain lacking the Ybt system causes fatal plague at low incidence when transmitted by fleas. Bacteriology and histology analyses revealed that a Ybt-negative strain caused only primary septicemic plague and atypical bubonic plague instead of the typical bubonic form of disease. The results provide new evidence that primary septicemic plague is a distinct clinical entity and suggest that unusual forms of plague may be caused by atypical Y. pestis strains.

  16. Plague in Egypt: Disease biology, history and contemporary analysis: A minireview

    Directory of Open Access Journals (Sweden)

    Wael M. Lotfy

    2015-07-01

    Full Text Available Plague is a zoonotic disease with a high mortality rate in humans. Unfortunately, it is still endemic in some parts of the world. Also, natural foci of the disease are still found in some countries. Thus, there may be a risk of global plague re-emergence. This work reviews plague biology, history of major outbreaks, and threats of disease re-emergence in Egypt. Based on the suspected presence of potential natural foci in the country, the global climate change, and the threat posed by some neighbouring countries disease re-emergence in Egypt should not be excluded. The country is in need for implementation of some preventive measures.

  17. [Mechanisms of power in disease: the case of the novel "The Plague" by Albert Camus].

    Science.gov (United States)

    Hernández-Mansilla, José Miguel

    2009-01-01

    This paper explores the elements of power that can be found in an epidemic like the plague. To undertake this task we first studied, the form of containment of the plague from a historical perspective and then, compare them with those described by Camus in his novel The Plague. We also studied the experience of sin among humans in an effort to determine divine power. This last point explores the fear of being touched during an epidemic and how this is overcome by the innate feeling of love among men. Finally in the novel, this is illustrated by the love of Orpheus for Eurydice.

  18. Plague in Egypt: Disease biology, history and contemporary analysis: A minireview

    OpenAIRE

    Lotfy, Wael M.

    2013-01-01

    Plague is a zoonotic disease with a high mortality rate in humans. Unfortunately, it is still endemic in some parts of the world. Also, natural foci of the disease are still found in some countries. Thus, there may be a risk of global plague re-emergence. This work reviews plague biology, history of major outbreaks, and threats of disease re-emergence in Egypt. Based on the suspected presence of potential natural foci in the country, the global climate change, and the threat posed by some nei...

  19. Prevention of bubonic and pneumonic plague using plant-derived vaccines.

    Science.gov (United States)

    Alvarez, M Lucrecia; Cardineau, Guy A

    2010-01-01

    Yersinia pestis, the causative agent of bubonic and pneumonic plague, is an extremely virulent bacterium but there are currently no approved vaccines for protection against this organism. Plants represent an economical and safer alternative to fermentation-based expression systems for the production of therapeutic proteins. The recombinant plague vaccine candidates produced in plants are based on the two most immunogenic antigens of Y. pestis: the fraction-1 capsular antigen (F1) and the low calcium response virulent antigen (V) either in combination or as a fusion protein (F1-V). These antigens have been expressed in plants using all three known possible strategies: nuclear transformation, chloroplast transformation and plant-virus-based expression vectors. These plant-derived plague vaccine candidates were successfully tested in animal models using parenteral, oral, or prime/boost immunization regimens. This review focuses on the recent research accomplishments towards the development of safe and effective pneumonic and bubonic plague vaccines using plants as bioreactors.

  20. Epidemiologic features of four successive annual outbreaks of bubonic plague in Mahajanga, Madagascar.

    Science.gov (United States)

    Boisier, Pascal; Rahalison, Lila; Rasolomaharo, Monique; Ratsitorahina, Maherisoa; Mahafaly, Mahafaly; Razafimahefa, Maminirana; Duplantier, Jean-Marc; Ratsifasoamanana, Lala; Chanteau, Suzanne

    2002-03-01

    From 1995 to 1998, outbreaks of bubonic plague occurred annually in the coastal city of Mahajanga, Madagascar. A total of 1,702 clinically suspected cases of bubonic plague were reported, including 515 laboratory confirmed by Yersinia pestis isolation (297), enzyme-linked immunosorbent assay, or both. Incidence was higher in males and young persons. Most buboes were inguinal, but children had a higher frequency of cervical or axillary buboes. Among laboratory-confirmed hospitalized patients, the case-fatality rate was 7.9%, although all Y. pestis isolates were sensitive to streptomycin, the recommended antibiotic. In this tropical city, plague outbreaks occur during the dry and cool season. Most cases are concentrated in the same crowded and unsanitary districts, a result of close contact among humans, rats, and shrews. Plague remains an important public health problem in Madagascar, and the potential is substantial for spread to other coastal cities and abroad.

  1. Epidemiology of Human Plague in the United States, 1900–2012

    Centers for Disease Control (CDC) Podcasts

    2015-02-23

    Dr. Kiersten Kugeler discusses the Epidemiology of Human Plague in the United States.  Created: 2/23/2015 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 2/23/2015.

  2. No evidence of deer mouse involvement in plague (Yersinia pestis) epizootics in prairie dogs.

    Science.gov (United States)

    Salkeld, Daniel J; Stapp, Paul

    2008-06-01

    Plague, the disease caused by the bacterium Yersinia pestis, can have devastating impacts on black-tailed prairie dog (Cynomys ludovicianus) colonies. One suggested mechanism behind sporadic prairie dog die-offs involves an alternative mammal host, such as the deer mouse (Peromyscus maniculatus), which often inhabits prairie dog colonies. We examined the flea populations of deer mice to investigate the potential of flea-borne transmission of plague between deer mice and prairie dogs in northern Colorado, where plague is active in prairie dog colonies. Deer mice were predominantly infested with the flea Aetheca wagneri, and were rarely infested with prairie dog fleas, Oropsylla hirsuta. Likelihood of flea infestation increased with average monthly temperature, and flea loads were higher in reproductive animals. These results suggest that the deer mouse is an unlikely maintenance host of plague in this region.

  3. Complete Protection against Pneumonic and Bubonic Plague after a Single Oral Vaccination.

    Science.gov (United States)

    Derbise, Anne; Hanada, Yuri; Khalifé, Manal; Carniel, Elisabeth; Demeure, Christian E

    2015-01-01

    No efficient vaccine against plague is currently available. We previously showed that a genetically attenuated Yersinia pseudotuberculosis producing the Yersinia pestis F1 antigen was an efficient live oral vaccine against pneumonic plague. This candidate vaccine however failed to confer full protection against bubonic plague and did not produce F1 stably. The caf operon encoding F1 was inserted into the chromosome of a genetically attenuated Y. pseudotuberculosis, yielding the VTnF1 strain, which stably produced the F1 capsule. Given orally to mice, VTnF1 persisted two weeks in the mouse gut and induced a high humoral response targeting both F1 and other Y. pestis antigens. The strong cellular response elicited was directed mostly against targets other than F1, but also against F1. It involved cells with a Th1-Th17 effector profile, producing IFNγ, IL-17, and IL-10. A single oral dose (108 CFU) of VTnF1 conferred 100% protection against pneumonic plague using a high-dose challenge (3,300 LD50) caused by the fully virulent Y. pestis CO92. Moreover, vaccination protected 100% of mice from bubonic plague caused by a challenge with 100 LD50 Y. pestis and 93% against a high-dose infection (10,000 LD50). Protection involved fast-acting mechanisms controlling Y. pestis spread out of the injection site, and the protection provided was long-lasting, with 93% and 50% of mice surviving bubonic and pneumonic plague respectively, six months after vaccination. Vaccinated mice also survived bubonic and pneumonic plague caused by a high-dose of non-encapsulated (F1-) Y. pestis. VTnF1 is an easy-to-produce, genetically stable plague vaccine candidate, providing a highly efficient and long-lasting protection against both bubonic and pneumonic plague caused by wild type or un-encapsulated (F1-negative) Y. pestis. To our knowledge, VTnF1 is the only plague vaccine ever reported that could provide high and durable protection against the two forms of plague after a single oral

  4. Complete Protection against Pneumonic and Bubonic Plague after a Single Oral Vaccination.

    Directory of Open Access Journals (Sweden)

    Anne Derbise

    Full Text Available No efficient vaccine against plague is currently available. We previously showed that a genetically attenuated Yersinia pseudotuberculosis producing the Yersinia pestis F1 antigen was an efficient live oral vaccine against pneumonic plague. This candidate vaccine however failed to confer full protection against bubonic plague and did not produce F1 stably.The caf operon encoding F1 was inserted into the chromosome of a genetically attenuated Y. pseudotuberculosis, yielding the VTnF1 strain, which stably produced the F1 capsule. Given orally to mice, VTnF1 persisted two weeks in the mouse gut and induced a high humoral response targeting both F1 and other Y. pestis antigens. The strong cellular response elicited was directed mostly against targets other than F1, but also against F1. It involved cells with a Th1-Th17 effector profile, producing IFNγ, IL-17, and IL-10. A single oral dose (108 CFU of VTnF1 conferred 100% protection against pneumonic plague using a high-dose challenge (3,300 LD50 caused by the fully virulent Y. pestis CO92. Moreover, vaccination protected 100% of mice from bubonic plague caused by a challenge with 100 LD50 Y. pestis and 93% against a high-dose infection (10,000 LD50. Protection involved fast-acting mechanisms controlling Y. pestis spread out of the injection site, and the protection provided was long-lasting, with 93% and 50% of mice surviving bubonic and pneumonic plague respectively, six months after vaccination. Vaccinated mice also survived bubonic and pneumonic plague caused by a high-dose of non-encapsulated (F1- Y. pestis.VTnF1 is an easy-to-produce, genetically stable plague vaccine candidate, providing a highly efficient and long-lasting protection against both bubonic and pneumonic plague caused by wild type or un-encapsulated (F1-negative Y. pestis. To our knowledge, VTnF1 is the only plague vaccine ever reported that could provide high and durable protection against the two forms of plague after a single

  5. Remote sensing for landscape epidemiology : spatial analysis of plague hosts in Kazakhstan

    OpenAIRE

    Wilschut, L.I.

    2015-01-01

    The spatial distribution of hosts is a crucial aspect for the understanding of infectious disease dynamics. In Kazakhstan, the great gerbil (Rhombomys opimus) is the main host for plague (Yersinia pestis infection) and poses a public health threat, yet their spatial distribution is unknown. Great gerbils are social animals that live in family groups in burrows in desert environments. Plague is transmitted from gerbil to gerbil via fleas, and can also be transmitted to humans. In Kazakhstan, a...

  6. Outbreak of Plague in a High Malaria Endemic Region - Nyimba District, Zambia, March-May 2015.

    Science.gov (United States)

    Sinyange, Nyambe; Kumar, Ramya; Inambao, Akatama; Moonde, Loveness; Chama, Jonathan; Banda, Mapopa; Tembo, Elliot; Nsonga, Beron; Mwaba, John; Fwoloshi, Sombo; Musokotwane, Kebby; Chizema, Elizabeth; Kapin'a, Muzala; Hang'ombe, Benard Mudenda; Baggett, Henry C; Hachaambwa, Lottie

    2016-08-12

    Outbreaks of plague have been recognized in Zambia since 1917 (1). On April 10, 2015, Zambia's Ministry of Health was notified by the Eastern Provincial Medical Office of possible bubonic plague cases in Nyimba District. Eleven patients with acute fever and cervical lymphadenopathy had been evaluated at two rural health centers during March 28-April 9, 2015; three patients died. To confirm the outbreak and develop control measures, the Zambia Ministry of Health's Field Epidemiology Training Program (ZFETP) conducted epidemiologic and laboratory investigations in partnership with the University of Zambia's schools of Medicine and Veterinary Medicine and the provincial and district medical offices. Twenty-one patients with clinically compatible plague were identified, with symptom onset during March 26-May 5, 2015. The median age was 8 years, and all patients were from the same village. Blood specimens or lymph node aspirates from six (29%) patients tested positive for Yersinia pestis by polymerase chain reaction (PCR). There is an urgent need to improve early identification and treatment of plague cases. PCR is a potential complementary tool for identifying plague, especially in areas with limited microbiologic capacity. Twelve (57%) patients, including all six with PCR-positive plague and all three who died, also tested positive for malaria by rapid diagnostic test (RDT). Plague patients coinfected with malaria might be misdiagnosed as solely having malaria, and appropriate antibacterial treatment to combat plague might not be given, increasing risk for mortality. Because patients with malaria might be coinfected with other pathogens, broad spectrum antibiotic treatment to cover other pathogens is recommended for all children with severe malaria, until a bacterial infection is excluded.

  7. [The North African plague and Charles Nicolle's theory of infectious diseases].

    OpenAIRE

    Ben, Néfissa Kmar; Moulin,Anne Marie

    2010-01-01

    Many infectious diseases were described in North Africa in 18th-19th centuries by European travellers. Most of them were allegedly imported by new migrant populations coming from sub-Saharan, European or Middle East countries. Plague outbreaks have been described since the Black Death as diseases of the Mediterranean harbours. Charles Nicolle and his collaborators at the Pasteur Institute were witnesses to the extinction of plague and typhus fever in Tunisia. Both could be considered as endem...

  8. Dissociation of Tissue Destruction and Bacterial Expansion during Bubonic Plague.

    Science.gov (United States)

    Guinet, Françoise; Avé, Patrick; Filali, Sofia; Huon, Christèle; Savin, Cyril; Huerre, Michel; Fiette, Laurence; Carniel, Elisabeth

    2015-10-01

    Activation and/or recruitment of the host plasmin, a fibrinolytic enzyme also active on extracellular matrix components, is a common invasive strategy of bacterial pathogens. Yersinia pestis, the bubonic plague agent, expresses the multifunctional surface protease Pla, which activates plasmin and inactivates fibrinolysis inhibitors. Pla is encoded by the pPla plasmid. Following intradermal inoculation, Y. pestis has the capacity to multiply in and cause destruction of the lymph node (LN) draining the entry site. The closely related, pPla-negative, Y. pseudotuberculosis species lacks this capacity. We hypothesized that tissue damage and bacterial multiplication occurring in the LN during bubonic plague were linked and both driven by pPla. Using a set of pPla-positive and pPla-negative Y. pestis and Y. pseudotuberculosis strains in a mouse model of intradermal injection, we found that pPla is not required for bacterial translocation to the LN. We also observed that a pPla-cured Y. pestis caused the same extensive histological lesions as the wild type strain. Furthermore, the Y. pseudotuberculosis histological pattern, characterized by infectious foci limited by inflammatory cell infiltrates with normal tissue density and follicular organization, was unchanged after introduction of pPla. However, the presence of pPla enabled Y. pseudotuberculosis to increase its bacterial load up to that of Y. pestis. Similarly, lack of pPla strongly reduced Y. pestis titers in LNs of infected mice. This pPla-mediated enhancing effect on bacterial load was directly dependent on the proteolytic activity of Pla. Immunohistochemistry of Pla-negative Y. pestis-infected LNs revealed extensive bacterial lysis, unlike the numerous, apparently intact, microorganisms seen in wild type Y. pestis-infected preparations. Therefore, our study demonstrates that tissue destruction and bacterial survival/multiplication are dissociated in the bubo and that the primary action of Pla is to protect

  9. Dissociation of Tissue Destruction and Bacterial Expansion during Bubonic Plague.

    Directory of Open Access Journals (Sweden)

    Françoise Guinet

    2015-10-01

    Full Text Available Activation and/or recruitment of the host plasmin, a fibrinolytic enzyme also active on extracellular matrix components, is a common invasive strategy of bacterial pathogens. Yersinia pestis, the bubonic plague agent, expresses the multifunctional surface protease Pla, which activates plasmin and inactivates fibrinolysis inhibitors. Pla is encoded by the pPla plasmid. Following intradermal inoculation, Y. pestis has the capacity to multiply in and cause destruction of the lymph node (LN draining the entry site. The closely related, pPla-negative, Y. pseudotuberculosis species lacks this capacity. We hypothesized that tissue damage and bacterial multiplication occurring in the LN during bubonic plague were linked and both driven by pPla. Using a set of pPla-positive and pPla-negative Y. pestis and Y. pseudotuberculosis strains in a mouse model of intradermal injection, we found that pPla is not required for bacterial translocation to the LN. We also observed that a pPla-cured Y. pestis caused the same extensive histological lesions as the wild type strain. Furthermore, the Y. pseudotuberculosis histological pattern, characterized by infectious foci limited by inflammatory cell infiltrates with normal tissue density and follicular organization, was unchanged after introduction of pPla. However, the presence of pPla enabled Y. pseudotuberculosis to increase its bacterial load up to that of Y. pestis. Similarly, lack of pPla strongly reduced Y. pestis titers in LNs of infected mice. This pPla-mediated enhancing effect on bacterial load was directly dependent on the proteolytic activity of Pla. Immunohistochemistry of Pla-negative Y. pestis-infected LNs revealed extensive bacterial lysis, unlike the numerous, apparently intact, microorganisms seen in wild type Y. pestis-infected preparations. Therefore, our study demonstrates that tissue destruction and bacterial survival/multiplication are dissociated in the bubo and that the primary action of Pla

  10. Are local plague endemicity and ecological characteristics of vectors and reservoirs related? A case study in north-east Tanzania

    Directory of Open Access Journals (Sweden)

    Herwig LEIRS

    2009-06-01

    Full Text Available The pattern of plague endemicity in Tanzania is characterized by continuous re-appearance of the disease in some locations, while in other neighbouring villages the disease has never or seldom been observed. To understand the reasons for this pattern, we studied small mammals and fleas species composition, diversity and relative abundances in two plague-endemic and two plague-free locations. We asked (a whether fleas more abundant in plague-endemic locations differ in their characteristic abundance and the degree of their host specificity from fleas most abundant in plague-free locations and (b whether hosts more abundant in plague-endemic locations differ in the diversity of their flea assemblages from hosts most abundant in plague-free locations. We characterized (a host species by species richness and degree of taxonomic relatedness of its flea assemblages and (b each flea species by its mean abundance and size, and degree of taxonomic relatedness of its host spectrum and compared their relative abundances between locations. No significant difference between plague-endemic and plague-free locations in either host density or any variable related to flea abundance or diversity was found. However, there was marginally significant effect of taxonomic distinctness of a flea assemblage harboured by a host on its probability to be more abundant in either plague-endemic or plague-free locations. Furthermore, hosts more abundant in plague-endemic locations tended to harbour closely-related fleas. Finally, while opportunistic and specialist fleas were equally distributed in both sets of locations, fleas exploiting distantly-related hosts were found mainly in plague-free locations during the rainy season. We suggest that the observed patterns might arise due to seasonal and spatial differences in local microclimatic conditions and landscape connectivity[Current Zoology 55(3:199–211, 2009].

  11. [The arrival of the plague in São Paulo in 1899].

    Science.gov (United States)

    do Nascimento, Dilene Raimundo

    2011-01-01

    In October 1899, the bubonic plague arrived in Brazil through the port of Santos. A city of intensive port activity, Santos was the gateway for a plague epidemic that devastated several cities in Brazil in the early 20th century and prompted joint action by several states to fight it. More importantly, given the difficulties and delays in importing anti-plague serum from Europe, it led to the creation of the Butantan Institute in Sao Paulo (in 1899) and the Municipal Serotherapeutic Institute in Rio de Janeiro (in 1900), which developed and standardized anti-plague serum and vaccines according to the particular conditions of the country. Until then, public health efforts had been isolated and had not reached the whole country. Oswaldo Cruz, newly arrived after three years of specialization at the Pasteur Institute in Paris, worked with scientists Adolfo Lutz and Vital Brazil on identifying the plague in Santos. This article analyzes the arrival of the bubonic plague epidemic in the state of Sao Paulo and the public health measures taken to combat the disease and provide patient care in the early part of the 20th century. The primary sources for this analysis were the São Paulo newspapers, especially O Estado de Sao Paulo, and reports from the Ministry of Justice and the President of the State of Sao Paulo.

  12. [The North African plague and Charles Nicolle's theory of infectious diseases].

    Science.gov (United States)

    Ben, Néfissa Kmar; Moulin, Anne Marie

    2010-01-01

    Many infectious diseases were described in North Africa in 18th-19th centuries by European travellers. Most of them were allegedly imported by new migrant populations coming from sub-Saharan, European or Middle East countries. Plague outbreaks have been described since the Black Death as diseases of the Mediterranean harbours. Charles Nicolle and his collaborators at the Pasteur Institute were witnesses to the extinction of plague and typhus fever in Tunisia. Both could be considered as endemo-epidemic diseases propagated by ancient nomad communities for centuries. Typhus was exported to other countries; plague was imported by Mediterranean travellers but also hid in unknown wild-animal reservoirs. The role of the bite of a rat's flea was not confirmed and the pneumonic form might have prevailed in the medieval North African cities. Association between plague, typhus, flu and other causes of immune deficiencies could explain the high morbidity and mortality caused by plague in the past. The authors comment the local history of plague at the light of the evolutionary laws of infectious disease proposed by Charles Nicolle in 1930.

  13. Flea abundance on black-tailed prairie dogs (Cynomys ludovicianus) increases during plague epizootics.

    Science.gov (United States)

    Tripp, Daniel W; Gage, Kenneth L; Montenieri, John A; Antolin, Michael F

    2009-06-01

    Black-tailed prairie dogs (Cynomys ludovicianus) on the Great Plains of the United States are highly susceptible to plague, caused by the bacterium Yersinia pestis, with mortality on towns during plague epizootics often approaching 100%. The ability of flea-borne transmission to sustain disease spread has been questioned because of inefficiency of flea vectors. However, even with low individual efficiency, overall transmission can be increased if flea abundance (the number of fleas on hosts) increases. Changes in flea abundance on hosts during plague outbreaks were recorded during a large-scale study of plague outbreaks in prairie dogs in north central Colorado during 3 years (2004-2007). Fleas were collected from live-trapped black-tailed prairie dogs before and during plague epizootics and tested by PCR for the presence of Y. pestis. The predominant fleas were two prairie dog specialists (Oropsylla hirsuta and Oropsylla tuberculata cynomuris), and a generalist flea species (Pulex simulans) was also recorded from numerous mammals in the area. The three species differ in seasonal abundance, with greatest abundance in spring (February and March) and fall (September and October). Flea abundance and infestation intensity increased during epizootics and were highest on prairie dogs with Y. pestis-infected fleas. Seasonal occurrence of epizootics among black-tailed prairie dogs was found to coincide with seasonal peaks in flea abundance. Concentration of infected fleas on surviving animals may account for rapid spread of plague during epizootics. In particular, the role of the generalist flea P. simulans was previously underappreciated.

  14. Climate-driven spatial dynamics of plague among prairie dog colonies.

    Science.gov (United States)

    Snäll, T; O'Hara, R B; Ray, C; Collinge, S K

    2008-02-01

    We present a Bayesian hierarchical model for the joint spatial dynamics of a host-parasite system. The model was fitted to long-term data on regional plague dynamics and metapopulation dynamics of the black-tailed prairie dog, a declining keystone species of North American prairies. The rate of plague transmission between colonies increases with increasing precipitation, while the rate of infection from unknown sources decreases in response to hot weather. The mean annual dispersal distance of plague is about 10 km, and topographic relief reduces the transmission rate. Larger colonies are more likely to become infected, but colony area does not affect the infectiousness of colonies. The results suggest that prairie dog movements do not drive the spread of plague through the landscape. Instead, prairie dogs are useful sentinels of plague epizootics. Simulations suggest that this model can be used for predicting long-term colony and plague dynamics as well as for identifying which colonies are most likely to become infected in a specific year.

  15. A Field Study of Plague and Tularemia in Rodents, Western Iran.

    Science.gov (United States)

    Mostafavi, Ehsan; Shahraki, Abdolrazagh Hashemi; Japoni-Nejad, Alireza; Esmaeili, Saber; Darvish, Jamshid; Sedaghat, Mohammad Mehdi; Mohammadi, Ali; Mohammadi, Zeinolabedin; Mahmoudi, Ahmad; Pourhossein, Behzad; Ghasemi, Ahmad; Gyuranecz, Miklós; Carniel, Elisabeth

    2017-04-01

    Kurdistan Province in Iran is a historical focus for plague and tularemia. This study aimed at assessing the current status of these two foci by studying their rodent reservoirs. Rodents were trapped and their ectoparasites were collected. The genus and species of both rodents and ectoparasites were determined. Serological analyses of rodent blood samples were done by enzyme-linked immunosorbent assay for plague and by standard tube agglutination assay for tularemia. Rodent spleen samples were subjected to bacterial culture, microscopic examination, and real-time PCR to search for active plague or tularemia infection. During this study, 245 rodents were trapped, of which the most abundant genera were Apodemus (40%), Mus (24.49%), and Meriones (12.65%). One hundred fifty-three fleas, 37 mites, and 54 ticks were collected on these rodents. The results of all direct and indirect tests were negative for plague. Serological tests were positive for tularemia in 4.8% of trapped rodents. This study is the first report on the presence of tularemia infection in rodents in Western Iran. Since Meriones persicus is a known reservoir for plague and tularemia, and this rodent carried plague and tularemia vectors in Marivan and Sanandaj districts, there is a real potential for the occurrence of these two diseases in this region.

  16. Identification of risk factors for plague in the West Nile Region of Uganda.

    Science.gov (United States)

    Eisen, Rebecca J; MacMillan, Katherine; Atiku, Linda A; Mpanga, Joseph T; Zielinski-Gutierrez, Emily; Graham, Christine B; Boegler, Karen A; Enscore, Russell E; Gage, Kenneth L

    2014-06-01

    Plague is an often fatal, primarily flea-borne rodent-associated zoonosis caused by Yersinia pestis. We sought to identify risk factors for plague by comparing villages with and without a history of human plague cases within a model-defined plague focus in the West Nile Region of Uganda. Although rat (Rattus rattus) abundance was similar inside huts within case and control villages, contact rates between rats and humans (as measured by reported rat bites) and host-seeking flea loads were higher in case villages. In addition, compared with persons in control villages, persons in case villages more often reported sleeping on reed or straw mats, storing food in huts where persons sleep, owning dogs and allowing them into huts where persons sleep, storing garbage inside or near huts, and cooking in huts where persons sleep. Compared with persons in case villages, persons in control villages more commonly reported replacing thatch roofing, and growing coffee, tomatoes, onions, and melons in agricultural plots adjacent to their homesteads. Rodent and flea control practices, knowledge of plague, distance to clinics, and most care-seeking practices were similar between persons in case villages and persons in control villages. Our findings reinforce existing plague prevention recommendations and point to potentially advantageous local interventions. © The American Society of Tropical Medicine and Hygiene.

  17. Mortality risk factors show similar trends in modern and historic populations exposed to plague.

    Science.gov (United States)

    Rubini, Mauro; Gualdi-Russo, Emanuela; Manzon, Vanessa S; Rinaldo, Natascia; Bianucci, Raffaella

    2016-05-31

    Plague has been responsible for two major historic pandemics (6th-8th century CE; 14th-19th century CE) and a modern one. The recent Malagasy plague outbreaks raised new concerns on the deadly potential of the plague-causing bacteria Yersinia pestis. Between September 2014 and April 2015, outbreaks of bubonic and pneumonic plague hit the Malagasy population. Two hundred and sixty-three cases, including 71 deaths, have been reported in 16 different districts with a case fatality rate of 27%. The scope of our study was to ascertain whether the risk factors for health in modern-day populations exposed to plague and in ancient populations that faced the two historic pandemics varied or remained substantially unaltered. The risk of mortality of the Malagasy population with those obtained from the reconstruction of three samples of European populations exposed to the historic pandemics was contrasted. The evidence shows that the risks of death are not uniform across age neither in modern nor in historic populations exposed to plague and shows precise concentrations in specific age groups (children between five and nine years of age and young adults). Although in the post-antibiotic era, the fatality rates have drastically reduced, both modern and historic populations were exposed to the same risk factors that are essentially represented by a low standard of environmental hygiene, poor nutrition, and weak health systems.

  18. Human activity spaces and plague risks in three contrasting landscapes in Lushoto District, Tanzania.

    Science.gov (United States)

    Hieronimo, Proches; Gulinck, Hubert; Kimaro, Didas N; Mulungu, Loth S; Kihupi, Nganga I; Msanya, Balthazar M; Leirs, Herwig; Deckers, Jozef A

    2014-07-01

    Since 1980 plague has been a human threat in the Western Usambara Mountains in Tanzania. However, the spatial-temporal pattern of plague occurrence remains poorly understood. The main objective of this study was to gain understanding of human activity patterns in relation to spatial distribution of fleas in Lushoto District. Data were collected in three landscapes differing in plague incidence. Field survey coupled with Geographic Information System (GIS) and physical sample collections were used to collect data in wet (April to June 2012) and dry (August to October 2012) seasons. Data analysis was done using GIS, one-way ANOVA and nonparametric statistical tools. The degree of spatial co-occurrence of potential disease vectors (fleas) and humans in Lushoto focus differs significantly (p ≤ 0.05) among the selected landscapes, and in both seasons. This trend gives a coarse indication of the possible association of the plague outbreaks and the human frequencies of contacting environments with fleas. The study suggests that plague surveillance and control programmes at landscape scale should consider the existence of plague vector contagion risk gradient from high to low incidence landscapes due to human presence and intensity of activities.

  19. Navigable rivers facilitated the spread and recurrence of plague in pre-industrial Europe

    Science.gov (United States)

    Pak Hong, Y. R.

    2016-12-01

    nfectious diseases have become a rising challenge to mankind in a globalizing world. Yet, little is known about the inland transmission of infectious diseases in history. In this study, we based on the spatio-temporal information of 5559 plague (Yersinia pestis) outbreaks in Europe and its neighboring regions in AD1347-1760 to statistically examine the connection between navigable rivers and plague outbreak. Our results showed that 95.5% of plague happened within 10km proximity of navigable rivers. Besides, the count of plague outbreak was positively correlated with the width of river and negatively correlated with the distance between city and river. This association remained robust in different regression model specifications. An increase of 100m in the width of river and a shortening of 1km distance between city and river resulted in 9 and 0.96 more plague outbreaks in our study period, respectively. We suggested that trade and transportation brought by river was an important medium for the spread and recurrence of plague in pre-industrial Europe.

  20. Comparative genomics of 2009 seasonal plague (Yersinia pestis in New Mexico.

    Directory of Open Access Journals (Sweden)

    Henry S Gibbons

    Full Text Available Plague disease caused by the gram-negative bacterium Yersinia pestis routinely affects animals and occasionally humans, in the western United States. The strains native to the North American continent are thought to be derived from a single introduction in the late 19(th century. The degree to which these isolates have diverged genetically since their introduction is not clear, and new genomic markers to assay the diversity of North American plague are highly desired. To assay genetic diversity of plague isolates within confined geographic areas, draft genome sequences were generated by 454 pyrosequencing from nine environmental and clinical plague isolates. In silico assemblies of Variable Number Tandem Repeat (VNTR loci were compared to laboratory-generated profiles for seven markers. High-confidence SNPs and small Insertion/Deletions (Indels were compared to previously sequenced Y. pestis isolates. The resulting panel of mutations allowed clustering of the strains and tracing of the most likely evolutionary trajectory of the plague strains. The sequences also allowed the identification of new putative SNPs that differentiate the 2009 isolates from previously sequenced plague strains and from each other. In addition, new insertion points for the abundant insertion sequences (IS of Y. pestis are present that allow additional discrimination of strains; several of these new insertions potentially inactivate genes implicated in virulence. These sequences enable whole-genome phylogenetic analysis and allow the unbiased comparison of closely related isolates of a genetically monomorphic pathogen.

  1. Small mammal distribution and diversity in a plague endemic area in West Usambara Mountains, Tanzania.

    Science.gov (United States)

    Ralaizafisoloarivony, Njaka A; Kimaro, Didas N; Kihupi, Nganga I; Mulungu, Loth S; Leirs, Herwig; Msanya, Balthazar M; Deckers, Jozef A; Gulinck, Hubert

    2014-07-01

    Small mammals play a role in plague transmission as hosts in all plague endemic areas. Information on distribution and diversity of small mammals is therefore important for plague surveillance and control in such areas. The objective of this study was to investigate small mammals' diversity and their distribution in plague endemic area in the West Usambara Mountains in north-eastern Tanzania. Landsat images and field surveys were used to select trapping locations in different landscapes. Three landscapes with different habitats were selected for trapping of small mammals. Three types of trap were used in order to maximise the number of species captured. In total, 188 animals and thirteen species were captured in 4,905 trap nights. Praomys delectorum and Mastomys natalensis both reported as plague hosts comprised 50% of all the animals trapped. Trap success increased with altitude. Species diversity was higher in plantation forest followed by shrub, compared to other habitats, regardless of landscape type. It would therefore seem that chances of plague transmission from small mammals to humans are much higher under shrub, natural and plantation forest habitats.

  2. Molecular characterization of Duck Plague virus isolated from Bangladesh

    Directory of Open Access Journals (Sweden)

    Md. Mostakin Ahamed

    2015-09-01

    Full Text Available Duck plague (DP is the most feared duck disease in the world. For isolation, identification, molecular detection and characterization of DP virus (DPV, a total of 94 samples were collected from commercial farms (n=6 and households (n=13 from Rajshahi (n=37, Netrokona (n=35 and Mymensingh (n=22 districts of Bangladesh. The samples were processed and inoculated into 11-13 days old embryonated duck eggs for virus propagation. Virus was identified using agar gel immunodiffusion test (AGIT and passive hemagglutination (PHA test, and was confirmed by polymerase chain reaction (PCR targeting DNA polymerase and gC genes, followed by sequencing. Pathogenicity tests were performed using duck embryos, ducklings and ducks. Among the 94 samples, 17 isolates were confirmed as DPV by PCR amplification of partial DNA polymerase (446-bp and gC genes (78-bp, respectively. One of the isolates (Anatid herpes 1 BAU DMH was sequenced and found to be closely related with a Chinese variant of DPV (GenBank: JQ647509.1. Thus, we assume that both Bangladeshi and Chinese isolates of DPV may have a common ancestor. [J Adv Vet Anim Res 2015; 2(3.000: 296-303

  3. Duck plague: carrier state and gross pathology in black ducks

    Science.gov (United States)

    Ossa, Jorge E.

    1975-01-01

    Duck plague (UP) is a highly fatal disease of ducks, geese, and swans (family Anatidae), produced by a reticulo-endotheliotrophic virus classified as a member of the Herpesvirus group. The disease was recognized in Europe in 1949. On the American continent, the disease was first diagnosed in the United States in 1967. Very little is known of DP virus ecology, particularly of the mechanisms of interepizootic survival and movement. The tendency of the IIerpesviruses to enter into a quiescent state after an overt or inapparent infection is a proven characteristic for most of the members of this group. Herpes simplex, which is the model of the Herpesviruses, is said to be the classical example of a persistent recurrent viral infection. Burnet and Williams (4) were the first to recognize this kind of relationship between herpes simplex and its host in 1939. Later, it was found that the reactivation of the virus can be brought on by a variety of stimuli either physiological (menstruation), pathological (anaphylactic shock), chemical (pesticides) or physical (sunburn). This same latency property has been proved for every member of this group of viruses which has been studied adequately, DP is among the few Herpesviruses for which the carrier state has not been demonstrated, but there is circumstantial evidence suggesting it. The carrier state for DP seems to be a likely explanation for the persistence and the particular pattern of movement of this disease.

  4. Are plague pits of particular use to palaeoepidemiologists?

    Science.gov (United States)

    Waldron, H A

    2001-02-01

    The demography and pattern of disease of skeletal assemblages may not accurately reflect those of the living population of which they were once a part. The hypothesis tested here was that skeletons from a mass disaster would more closely approximate to a living population than those from a conventional cemetery. Six hundred skeletons recovered from a Black Death plague pit in London were compared with 236 skeletons recovered from an overlying medieval cemetery. Age and sex were determined by standard anthropological means by a single observer and adjustments were made to correct for those skeletons for which either or both could not be established. An estimate of age structure of the living medieval population of London was made, using model life tables. The age and sex distribution and the pattern of disease in the Black Death skeletons did not differ substantially from those in the control group of skeletons. Both assemblages tended to overestimate the numbers in the younger age groups of the model population and underestimate the numbers in the oldest age group. On the evidence from this single site, a skeletal assemblage from a mass disaster does not provide a better representation of the living population from which it was derived than that from a conventional cemetery.

  5. [Francisco Gavaldá, ahead of his time in the social statistics study of bubonic plague (1679)].

    Science.gov (United States)

    López Piñero, José María

    2006-01-01

    In 1651, Francisco Gavaldá (1618-1686) authored the first social statistics study on the bubonic plague which scourged western Europe in the mid-seventeenth century. specifically the plague having racked Valencia in 1647. Gavaldá was, in fact the first to study the plague not only statistically, but also from a social standpoint, denouncing the fact that it especially affected the poor, totally independently of the interests of the powerful.

  6. Duration of plague (Yersinia pestis) outbreaks in black-tailed prairie dog (Cynomys ludovicianus) colonies of northern Colorado.

    Science.gov (United States)

    St Romain, Krista; Tripp, Daniel W; Salkeld, Daniel J; Antolin, Michael F

    2013-09-01

    Plague, caused by the bacterium Yersinia pestis, triggers die-offs in colonies of black-tailed prairie dogs (Cynomys ludovicianus), but the time-frame of plague activity is not well understood. We document plague activity in fleas from prairie dogs and their burrows on three prairie dog colonies that suffered die-offs. We demonstrate that Y. pestis transmission occurs over periods from several months to over a year in prairie dog populations before observed die-offs.

  7. Are local plague endemicity and ecological characteristics of vectors and reservoirs related? A case study in north-east Tanzania

    Institute of Scientific and Technical Information of China (English)

    Anne LAUDISOIT; Simon NEERINCKX; Rhodes H.MAKUNDI; Herwig LEIRS; Boris R.KRASNOV

    2009-01-01

    The pattern of plague endemicity in Tanzania is characterized by continuous re-appearance of the disease in some locations, while in other neighbouring villages the disease has never or seldom been observed. To understand the reasons for this pattern, we studied small mammal and flea species composition, diversity and relative abundances in two plague-endemic and two plague-free locations. We asked (a) whether fleas more abundant in plague-endemic locations differ in their characteristic abundance and the degree of their host specificity from fleas more abundant in plague-free locations and (b) whether hosts most abundant in plagne-endemic locations differ in the diversity of their flea assemblages from hosts most abundant in plague-free locations. We characterized (a) each host species by species richness and degree of taxonomic relatedness of its flea assemblages and (b) each flea species by its mean abundance and size, and degree of taxonomic relatedness of its host spectrum and compared their relative abundances between locations. No significant difference between plague-endemic and plague-free locations in either host density or any variable related to flea abundance or diversity was found. However, there was marginally significant effect of taxonomic distinctness of a flea assemblage harboured by a host on its probability to be more abundant in either plague-endemic or plague-free locations. Furthermore, hosts more abundant in plague-endemic locations tended to harbeur closely-related fleas. Finally, while opportunistic and specialist fleas were equally distributed in both sets of locations, fleas exploiting distantly-related hosts were found mainly in plague-free locations during the rainy season. We suggest that the observed patterns might arise due to seasonal and spatial differences in local microclimatic conditions and landscape connectivity.

  8. Immune responses to plague infection in wild Rattus rattus, in Madagascar: a role in foci persistence?

    Science.gov (United States)

    Andrianaivoarimanana, Voahangy; Telfer, Sandra; Rajerison, Minoarisoa; Ranjalahy, Michel A; Andriamiarimanana, Fehivola; Rahaingosoamamitiana, Corinne; Rahalison, Lila; Jambou, Ronan

    2012-01-01

    Plague is endemic within the central highlands of Madagascar, where its main reservoir is the black rat, Rattus rattus. Typically this species is considered susceptible to plague, rapidly dying after infection inducing the spread of infected fleas and, therefore, dissemination of the disease to humans. However, persistence of transmission foci in the same area from year to year, supposes mechanisms of maintenance among which rat immune responses could play a major role. Immunity against plague and subsequent rat survival could play an important role in the stabilization of the foci. In this study, we aimed to investigate serological responses to plague in wild black rats from endemic areas of Madagascar. In addition, we evaluate the use of a recently developed rapid serological diagnostic test to investigate the immune response of potential reservoir hosts in plague foci. We experimentally infected wild rats with Yersinia pestis to investigate short and long-term antibody responses. Anti-F1 IgM and IgG were detected to evaluate this antibody response. High levels of anti-F1 IgM and IgG were found in rats one and three weeks respectively after challenge, with responses greatly differing between villages. Plateau in anti-F1 IgM and IgG responses were reached for as few as 500 and 1500 colony forming units (cfu) inoculated respectively. More than 10% of rats were able to maintain anti-F1 responses for more than one year. This anti-F1 response was conveniently followed using dipsticks. Inoculation of very few bacteria is sufficient to induce high immune response in wild rats, allowing their survival after infection. A great heterogeneity of rat immune responses was found within and between villages which could heavily impact on plague epidemiology. In addition, results indicate that, in the field, anti-F1 dipsticks are efficient to investigate plague outbreaks several months after transmission.

  9. The innate immune response may be important for surviving plague in wild Gunnison's prairie dogs.

    Science.gov (United States)

    Busch, Joseph D; Van Andel, Roger; Stone, Nathan E; Cobble, Kacy R; Nottingham, Roxanne; Lee, Judy; VerSteeg, Michael; Corcoran, Jeff; Cordova, Jennifer; Van Pelt, William; Shuey, Megan M; Foster, Jeffrey T; Schupp, James M; Beckstrom-Sternberg, Stephen; Beckstrom-Sternberg, James; Keim, Paul; Smith, Susan; Rodriguez-Ramos, Julia; Williamson, Judy L; Rocke, Tonie E; Wagner, David M

    2013-10-01

    Prairie dogs (Cynomys spp.) are highly susceptible to Yersinia pestis, with ≥99% mortality reported from multiple studies of plague epizootics. A colony of Gunnison's prairie dogs (Cynomys gunnisoni) in the Aubrey Valley (AV) of northern Arizona appears to have survived several regional epizootics of plague, whereas nearby colonies have been severely affected by Y. pestis. To examine potential mechanisms accounting for survival in the AV colony, we conducted a laboratory Y. pestis challenge experiment on 60 wild-caught prairie dogs from AV and from a nearby, large colony with frequent past outbreaks of plague, Espee (n = 30 per colony). Test animals were challenged subcutaneously with the fully virulent Y. pestis strain CO92 at three doses: 50, 5,000, and 50,000 colony-forming units (cfu); this range is lethal in black-tailed prairie dogs (Cynomys ludovicianus). Contrary to our expectations, only 40% of the animals died. Although mortality trended higher in the Espee colony (50%) compared with AV (30%), the differences among infectious doses were not statistically significant. Only 39% of the survivors developed moderate to high antibody levels to Y. pestis, indicating that mechanisms other than humoral immunity are important in resistance to plague. The ratio of neutrophils to lymphocytes was not correlated with plague survival in this study. However, several immune proteins with roles in innate immunity (VCAM-1, CXCL-1, and vWF) were upregulated during plague infection and warrant further inquiry into their role for protection against this disease. These results suggest plague resistance exists in wild populations of the Gunnison's prairie dog and provide important directions for future studies.

  10. The innate immune response may be important for surviving plague in wild Gunnison's prairie dogs

    Science.gov (United States)

    Busch, Joseph D.; Van Andel, Roger; Stone, Nathan E.; Cobble, Kacy R.; Nottingham, Roxanne; Lee, Judy; VerSteeg, Michael; Corcoran, Jeff; Cordova, Jennifer; Van Pelt, William E.; Shuey, Megan M.; Foster, Jeffrey T.; Schupp, James M.; Beckstrom-Sternberg, Stephen; Beckstrom-Sternberg, James; Keim, Paul; Smith, Susan; Rodriguez-Ramos, Julia; Williamson, Judy L.; Rocke, Tonie E.; Wagner, David M.

    2013-01-01

    Prairie dogs (Cynomys spp.) are highly susceptible to Yersinia pestis, with ≥99% mortality reported from multiple studies of plague epizootics. A colony of Gunnison's prairie dogs (Cynomys gunnisoni) in the Aubrey Valley (AV) of northern Arizona appears to have survived several regional epizootics of plague, whereas nearby colonies have been severely affected by Y. pestis. To examine potential mechanisms accounting for survival in the AV colony, we conducted a laboratory Y. pestis challenge experiment on 60 wild-caught prairie dogs from AV and from a nearby, large colony with frequent past outbreaks of plague, Espee (n = 30 per colony). Test animals were challenged subcutaneously with the fully virulent Y. pestis strain CO92 at three doses: 50, 5,000, and 50,000 colony-forming units (cfu); this range is lethal in black-tailed prairie dogs (Cynomys ludovicianus). Contrary to our expectations, only 40% of the animals died. Although mortality trended higher in the Espee colony (50%) compared with AV (30%), the differences among infectious doses were not statistically significant. Only 39% of the survivors developed moderate to high antibody levels to Y. pestis, indicating that mechanisms other than humoral immunity are important in resistance to plague. The ratio of neutrophils to lymphocytes was not correlated with plague survival in this study. However, several immune proteins with roles in innate immunity (VCAM-1, CXCL-1, and vWF) were upregulated during plague infection and warrant further inquiry into their role for protection against this disease. These results suggest plague resistance exists in wild populations of the Gunnison's prairie dog and provide important directions for future studies.

  11. Sylvatic plague vaccine partially protects prairie dogs (Cynomys spp.) in field trials

    Science.gov (United States)

    Rocke, Tonie E.; Tripp, Daniel W.; Russell, Robin E.; Abbott, Rachel C.; Richgels, Katherine; Matchett, Marc R.; Biggins, Dean E.; Griebel, Randall; Schroeder, Greg; Grassel, Shaun M.; Pipkin, David R.; Cordova, Jennifer; Kavalunas, Adam; Maxfield, Brian; Boulerice, Jesse; Miller, Michael W.

    2017-01-01

    Sylvatic plague, caused by Yersinia pestis, frequently afflicts prairie dogs (Cynomys spp.), causing population declines and local extirpations. We tested the effectiveness of bait-delivered sylvatic plague vaccine (SPV) in prairie dog colonies on 29 paired placebo and treatment plots (1–59 ha in size; average 16.9 ha) in 7 western states from 2013 to 2015. We compared relative abundance (using catch per unit effort (CPUE) as an index) and apparent survival of prairie dogs on 26 of the 29 paired plots, 12 with confirmed or suspected plague (Y. pestis positive carcasses or fleas). Even though plague mortality occurred in prairie dogs on vaccine plots, SPV treatment had an overall positive effect on CPUE in all three years, regardless of plague status. Odds of capturing a unique animal were 1.10 (95% confidence interval [C.I.] 1.02–1.19) times higher per trap day on vaccine-treated plots than placebo plots in 2013, 1.47 (95% C.I. 1.41–1.52) times higher in 2014 and 1.19 (95% C.I. 1.13–1.25) times higher in 2015. On pairs where plague occurred, odds of apparent survival were 1.76 (95% Bayesian credible interval [B.C.I.] 1.28–2.43) times higher on vaccine plots than placebo plots for adults and 2.41 (95% B.C.I. 1.72–3.38) times higher for juveniles. Our results provide evidence that consumption of vaccine-laden baits can protect prairie dogs against plague; however, further evaluation and refinement are needed to optimize SPV use as a management tool.

  12. A historical vignette (15). "Be proud of yourself: you have a history!" The nose and the plague.

    Science.gov (United States)

    Tainmont, J

    2009-01-01

    The nose and the plague. Although the plague does not cause any specific nasal pathology, the miasma theory and the repulsive smell of the disease were factors that contributed to a strong emphasis on the nose. To stop the spread of the disease, it was thought necessary to saturate the nose with protective scents (hence the nose of the plague doctors) (Figure 1), or simply to hold one's nose. Moreover, the nose was long considered to be an outlet for mucus from the encephalon, and so induced nose bleeding and sneezing were advised when the plague seemed to be attacking the brain.

  13. Historical Epidemics Cartography Generated by Spatial Analysis: Mapping the Heterogeneity of Three Medieval "Plagues" in Dijon: e0143866

    National Research Council Canada - National Science Library

    Pierre Galanaud; Anne Galanaud; Patrick Giraudoux

    2015-01-01

    .... We mapped "plague" deaths during three epidemics of the early 15th century, analyzed spatial distributions by applying the Kulldorff's method, and determined their relationships with the distribution...

  14. The abundance threshold for plague as a critical percolation phenomenon.

    Science.gov (United States)

    Davis, S; Trapman, P; Leirs, H; Begon, M; Heesterbeek, J A P

    2008-07-31

    Percolation theory is most commonly associated with the slow flow of liquid through a porous medium, with applications to the physical sciences. Epidemiological applications have been anticipated for disease systems where the host is a plant or volume of soil, and hence is fixed in space. However, no natural examples have been reported. The central question of interest in percolation theory, the possibility of an infinite connected cluster, corresponds in infectious disease to a positive probability of an epidemic. Archived records of plague (infection with Yersinia pestis) in populations of great gerbils (Rhombomys opimus) in Kazakhstan have been used to show that epizootics only occur when more than about 0.33 of the burrow systems built by the host are occupied by family groups. The underlying mechanism for this abundance threshold is unknown. Here we present evidence that it is a percolation threshold, which arises from the difference in scale between the movements that transport infectious fleas between family groups and the vast size of contiguous landscapes colonized by gerbils. Conventional theory predicts that abundance thresholds for the spread of infectious disease arise when transmission between hosts is density dependent such that the basic reproduction number (R(0)) increases with abundance, attaining 1 at the threshold. Percolation thresholds, however, are separate, spatially explicit thresholds that indicate long-range connectivity in a system and do not coincide with R(0) = 1. Abundance thresholds are the theoretical basis for attempts to manage infectious disease by reducing the abundance of susceptibles, including vaccination and the culling of wildlife. This first natural example of a percolation threshold in a disease system invites a re-appraisal of other invasion thresholds, such as those for epidemic viral infections in African lions (Panthera leo), and of other disease systems such as bovine tuberculosis (caused by Mycobacterium bovis) in

  15. Epidemiological analysis of the Eyam plague outbreak of 1665–1666

    Science.gov (United States)

    Whittles, Lilith K.

    2016-01-01

    Plague, caused by the bacterium Yersinia pestis, is one of the deadliest infectious diseases in human history, and still causes worrying outbreaks in Africa and South America. Despite the historical and current importance of plague, several questions remain unanswered concerning its transmission routes and infection risk factors. The plague outbreak that started in September 1665 in the Derbyshire village of Eyam claimed 257 lives over 14 months, wiping out entire families. Since previous attempts at modelling the Eyam plague, new data have been unearthed from parish records revealing a much more complete record of the disease. Using a stochastic compartmental model and Bayesian analytical methods, we found that both rodent-to-human and human-to-human transmission played an important role in spreading the infection, and that they accounted, respectively, for a quarter and three-quarters of all infections, with a statistically significant seasonality effect. We also found that the force of infection was stronger for infectious individuals living in the same household compared with the rest of the village. Poverty significantly increased the risk of disease, whereas adulthood decreased the risk. These results on the Eyam outbreak contribute to the current debate on the relative importance of plague transmission routes. PMID:27170724

  16. Current Perspectives on Plague Vector Control in Madagascar: Susceptibility Status of Xenopsylla cheopis to 12 Insecticides.

    Science.gov (United States)

    Miarinjara, Adélaïde; Boyer, Sébastien

    2016-02-01

    Plague is a rodent disease transmissible to humans by infected flea bites, and Madagascar is one of the countries with the highest plague incidence in the world. This study reports the susceptibility of the main plague vector Xenopsylla cheopis to 12 different insecticides belonging to 4 insecticide families (carbamates, organophosphates, pyrethroids and organochlorines). Eight populations from different geographical regions of Madagascar previously resistant to deltamethrin were tested with a World Health Organization standard bioassay. Insecticide susceptibility varied amongst populations, but all of them were resistant to six insecticides belonging to pyrethroid and carbamate insecticides (alphacypermethrin, lambdacyhalothrin, etofenprox, deltamethrin, bendiocarb and propoxur). Only one insecticide (dieldrin) was an efficient pulicide for all flea populations. Cross resistances were suspected. This study proposes at least three alternative insecticides (malathion, fenitrothion and cyfluthrin) to replace deltamethrin during plague epidemic responses, but the most efficient insecticide may be different for each population studied. We highlight the importance of continuous insecticide susceptibility surveillance in the areas of high plague risk in Madagascar.

  17. Kinetics of disease progression and host response in a rat model of bubonic plague.

    Science.gov (United States)

    Sebbane, Florent; Gardner, Donald; Long, Daniel; Gowen, Brian B; Hinnebusch, B Joseph

    2005-05-01

    Plague, caused by the gram-negative bacterium Yersinia pestis, primarily affects rodents but is also an important zoonotic disease of humans. Bubonic plague in humans follows transmission by infected fleas and is characterized by an acute, necrotizing lymphadenitis in the regional lymph nodes that drain the intradermal flea bite site. Septicemia rapidly follows with spread to spleen, liver, and other organs. We developed a model of bubonic plague using the inbred Brown Norway strain of Rattus norvegicus to characterize the progression and kinetics of infection and the host immune response after intradermal inoculation of Y. pestis. The clinical signs and pathology in the rat closely resembled descriptions of human bubonic plague. The bacteriology; histopathology; host cellular response in infected lymph nodes, blood, and spleen; and serum cytokine levels were analyzed at various times after infection to determine the kinetics and route of disease progression and to evaluate hypothesized Y. pestis pathogenic mechanisms. Understanding disease progression in this rat infection model should facilitate further investigations into the molecular pathogenesis of bubonic plague and the immune response to Y. pestis at different stages of the disease.

  18. [Primary pneumonic plague with nosocomial transmission in La Libertad, Peru 2010].

    Science.gov (United States)

    Donaires, Luis F; Céspedes, Manuel; Valencia, Pedro; Salas, Juan Carlos; Luna, María E; Castañeda, Alex; Peralta, Víctor; Cabezas, César; Pachas, Paul E

    2010-09-01

    Pneumonic plague is one of the clinical forms of plague, of low frequency and high mortality, transmitted by direct inhalation of Yersinia pestis coming from an animal or from person to person. To describe the clinical and epidemiological characteristics of the cases of primary pneumonic plague in an outbreak in the north of Peru. The clinical records of the confirmed cases of primary pneumonic plague presenting in an outbreak occurring in La Libertad, in July 2010, were reviewed, also the search and contact investigation was performed. The index case was identified, as well as three additional cases, out of these, two were nosocomial infections related to the index case. The initial clinical presentation was characterized by sudden onset of fever, chills, myalgia and chest pain, which in less than 24 hours evolved to hypotension and cyanosis. The initiation of specific treatment varied from 2 to 12 days, and cases with prompt initiation of treatment had a better clinical outcome. The lethality was 50% (2/4). Nosocomial transmission of pneumonic plague in Peru is evidenced, with severe clinical manifestations and high lethality.

  19. Current Perspectives on Plague Vector Control in Madagascar: Susceptibility Status of Xenopsylla cheopis to 12 Insecticides

    Science.gov (United States)

    Miarinjara, Adélaïde; Boyer, Sébastien

    2016-01-01

    Plague is a rodent disease transmissible to humans by infected flea bites, and Madagascar is one of the countries with the highest plague incidence in the world. This study reports the susceptibility of the main plague vector Xenopsylla cheopis to 12 different insecticides belonging to 4 insecticide families (carbamates, organophosphates, pyrethroids and organochlorines). Eight populations from different geographical regions of Madagascar previously resistant to deltamethrin were tested with a World Health Organization standard bioassay. Insecticide susceptibility varied amongst populations, but all of them were resistant to six insecticides belonging to pyrethroid and carbamate insecticides (alphacypermethrin, lambdacyhalothrin, etofenprox, deltamethrin, bendiocarb and propoxur). Only one insecticide (dieldrin) was an efficient pulicide for all flea populations. Cross resistances were suspected. This study proposes at least three alternative insecticides (malathion, fenitrothion and cyfluthrin) to replace deltamethrin during plague epidemic responses, but the most efficient insecticide may be different for each population studied. We highlight the importance of continuous insecticide susceptibility surveillance in the areas of high plague risk in Madagascar. PMID:26844772

  20. Gene flow in a Yersinia pestis vector, Oropsylla hirsuta, during a plague epizootic

    Directory of Open Access Journals (Sweden)

    Philip H. Jones , Leigh R. Washburn & Hugh B. Britten

    2011-09-01

    Full Text Available Background & objectives: Appreciating how Yersinia pestis, the etiological agent of plague, spreads amongblack-tailed prairie dog (Cynomys ludovicianus colonies (BTPD, is vital to wildlife conservation programsin North American grasslands. A little-studied aspect of the system is the role of Y. pestis vectors, i.e. fleas,play in the spreading of plague in natural settings. We investigated the genetic structure and variability of acommon prairie dog flea (Oropsylla hirsuta in BTPD colonies in order to examine dispersal patterns. Giventhat this research took place during a widespread plague epizootic, there was the added advantage of gaininginformation on the dynamics of sylvatic plague.Methods & Results: Oropsylla hirsuta were collected from BTPD burrows in nine colonies from May 2005 toJuly 2005, and eight polymorphic microsatellite markers were used to generate genotypic data from them.Gene flow estimates revealed low genetic differentiation among fleas sampled from different colonies. NestedPCR plague assays confirmed the presence of Y. pestis with the average Y. pestis prevalence across all ninecolonies at 12%. No significant correlations were found between the genetic variability and gene flow of O.hirsuta and Y. pestis prevalence on a per-colony basis.Conclusion: Oropsylla hirsuta dispersal among BTPD colonies was high, potentially explaining the rapidspread of Y. pestis in our study area in 2005 and 2006.

  1. Gene flow in a Yersinia pestis vector, Oropsylla hirsuta, during a plague epizootic.

    Science.gov (United States)

    Jones, Philip H; Washburn, Leigh R; Britten, Hugh B

    2011-09-01

    Appreciating how Yersinia pestis, the etiological agent of plague, spreads among black - tailed prairie dog (Cynomys ludovicianus) colonies (BTPD), is vital to wildlife conservation programs in North American grasslands. A little - studied aspect of the system is the role of Y. pestis vectors, i.e. fleas, play in the spreading of plague in natural settings. We investigated the genetic structure and variability of a common prairie dog flea (Oropsylla hirsuta) in BTPD colonies in order to examine dispersal patterns. Given that this research took place during a widespread plague epizootic, there was the added advantage of gaining information on the dynamics of sylvatic plague. Oropsylla hirsuta were collected from BTPD burrows in nine colonies from May 2005 to July 2005, and eight polymorphic microsatellite markers were used to generate genotypic data from them. Gene flow estimates revealed low genetic differentiation among fleas sampled from different colonies. NestedPCR plague assays confirmed the presence of Y. pestis with the average Y. pestis prevalence across all nine colonies at 12%. No significant correlations were found between the genetic variability and gene flow of O. hirsuta and Y. pestis prevalence on a per -colony basis. Oropsylla hirsuta dispersal among BTPD colonies was high, potentially explaining the rapid spread of Y. pestis in our study area in 2005 and 2006.

  2. Sylvatic plague reduces genetic variability in black-tailed prairie dogs.

    Science.gov (United States)

    Trudeau, Kristie M; Britten, Hugh B; Restani, Marco

    2004-04-01

    Small, isolated populations are vulnerable to loss of genetic diversity through in-breeding and genetic drift. Sylvatic plague due to infection by the bacterium Yersinia pestis caused an epizootic in the early 1990s resullting in declines and extirpations of many black-tailed prairie dog (Cynomys ludovicianus) colonies in north-central Montana, USA. Plague-induced population bottlenecks may contribute to significant reductions in genetic variability. In contrast, gene flow maintains genetic variability within colonies. We investigated the impacts of the plague epizootic and distance to nearest colony on levels of genetic variability in six prairie dog colonies sampled between June 1999 and July 2001 using 24 variable randomly amplified polymorphic DNA (RAPD) markers. Number of effective alleles per locus (n(e)) and gene diversity (h) were significantly decreased in the three colonies affected by plague that were recovering from the resulting bottlenecks compared with the three colonies that did not experience plague. Genetic variability was not significantly affected by geographic distance between colonies. The majority of variance in gene fieqnencies was found within prairie clog colonies. Conservation of genetic variability in black-tailed prairie dogs will require the preservation of both large and small colony complexes and the gene flow amonog them.

  3. Influence of satellite-derived rainfall patterns on plague occurrence in northeast Tanzania.

    Science.gov (United States)

    Debien, Annekatrien; Neerinckx, Simon; Kimaro, Didas; Gulinck, Hubert

    2010-12-13

    In the tropics, rainfall data are seldom accurately recorded, and are often discontinuous in time. In the scope of plague-research in northeast Tanzania, we adapted previous research to reconstruct rainfall patterns at a suitable resolution (1 km), based on time series of NDVI: more accurate satellite imagery was used, in the form of MODIS NDVI, and rainfall data were collected from the TRMM sensors instead of in situ data. First, we established a significant relationship between monthly rainfall and monthly composited MODIS NDVI. The established linear relationship was then used to reconstruct historic precipitation patterns over a mountainous area in northeastern Tanzania. We validated the resulting precipitation estimates with in situ rainfall time series of three meteorological stations located in the study area. Taking the region's topography into account, a correlation coefficient of 0.66 was obtained for two of the three meteorological stations. Our results suggest that the adapted strategy can be applied fruitfully to estimate rainfall variability and seasonality, despite the underestimation of overall rainfall rates. Based on this model, rainfall in previous years (1986) is modelled to obtain a dataset with which we can compare plague occurrence in the area. A positive correlation of 82% is obtained between high rainfall rates and plague incidence with a two month lag between rainfall and plague cases. We conclude that the obtained results are satisfactory in support of the human plague research in which this study is embedded, and that this approach can be applied in other studies with similar goals.

  4. Two medieval plague treatises and their afterlife in early modern England.

    Science.gov (United States)

    Keiser, George R

    2003-07-01

    This study of an adaptation of the popular John of Burgundy plague treatise by Thomas Moulton, a Dominican friar, ca. 1475, and a translation of the so-called Canutus plague treatise by Thomas Paynell, printed 1534, shows how the medieval traditions they represent were carried forward, well into the sixteenth century, and also subjected to change in light of religious, moral, and medical concerns of early modern England. The former had a long life in print, ca. 1530-1580, whereas Paynell's translation exists in one printed version. Moulton's adaptation differs from its original and from the Canutus treatise in putting great emphasis on the idea that onsets of plague were acts of divine retribution for human sinfulness. In this respect, Moulton reshaped the tradition of the medieval plague treatise and anticipated the religious and social construction of plague that would take shape in the first half of the sixteenth century. Its long history in print indicates that Moulton's treatise expressed the spirit of that construction and probably influenced the construction as well. The contrasting histories of the two treatises attest not only to the dramatic change brought about by religious and social forces in the sixteenth century, but to a growing recognition of the value of the printing press for disseminating medical information-in forms that served social and ideological ends.

  5. A High-Coverage Yersinia pestis Genome from a Sixth-Century Justinianic Plague Victim.

    Science.gov (United States)

    Feldman, Michal; Harbeck, Michaela; Keller, Marcel; Spyrou, Maria A; Rott, Andreas; Trautmann, Bernd; Scholz, Holger C; Päffgen, Bernd; Peters, Joris; McCormick, Michael; Bos, Kirsten; Herbig, Alexander; Krause, Johannes

    2016-11-01

    The Justinianic Plague, which started in the sixth century and lasted to the mid eighth century, is thought to be the first of three historically documented plague pandemics causing massive casualties. Historical accounts and molecular data suggest the bacterium Yersinia pestis as its etiological agent. Here we present a new high-coverage (17.9-fold) Y. pestis genome obtained from a sixth-century skeleton recovered from a southern German burial site close to Munich. The reconstructed genome enabled the detection of 30 unique substitutions as well as structural differences that have not been previously described. We report indels affecting a lacl family transcription regulator gene as well as nonsynonymous substitutions in the nrdE, fadJ, and pcp genes, that have been suggested as plague virulence determinants or have been shown to be upregulated in different models of plague infection. In addition, we identify 19 false positive substitutions in a previously published lower-coverage Y. pestis genome from another archaeological site of the same time period and geographical region that is otherwise genetically identical to the high-coverage genome sequence reported here, suggesting low-genetic diversity of the plague during the sixth century in rural southern Germany. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  6. Diverse Genotypes of Yersinia pestis Caused Plague in Madagascar in 2007.

    Science.gov (United States)

    Riehm, Julia M; Projahn, Michaela; Vogler, Amy J; Rajerison, Minoaerisoa; Andersen, Genevieve; Hall, Carina M; Zimmermann, Thomas; Soanandrasana, Rahelinirina; Andrianaivoarimanana, Voahangy; Straubinger, Reinhard K; Nottingham, Roxanne; Keim, Paul; Wagner, David M; Scholz, Holger C

    2015-06-01

    Yersinia pestis is the causative agent of human plague and is endemic in various African, Asian and American countries. In Madagascar, the disease represents a significant public health problem with hundreds of human cases a year. Unfortunately, poor infrastructure makes outbreak investigations challenging. DNA was extracted directly from 93 clinical samples from patients with a clinical diagnosis of plague in Madagascar in 2007. The extracted DNAs were then genotyped using three molecular genotyping methods, including, single nucleotide polymorphism (SNP) typing, multi-locus variable-number tandem repeat analysis (MLVA), and Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) analysis. These methods provided increasing resolution, respectively. The results of these analyses revealed that, in 2007, ten molecular groups, two newly described here and eight previously identified, were responsible for causing human plague in geographically distinct areas of Madagascar. Plague in Madagascar is caused by numerous distinct types of Y. pestis. Genotyping method choice should be based upon the discriminatory power needed, expense, and available data for any desired comparisons. We conclude that genotyping should be a standard tool used in epidemiological investigations of plague outbreaks.

  7. Yersinia pestis IS1541 transposition provides for escape from plague immunity.

    Science.gov (United States)

    Cornelius, Claire A; Quenee, Lauriane E; Elli, Derek; Ciletti, Nancy A; Schneewind, Olaf

    2009-05-01

    Yersinia pestis is perhaps the most feared infectious agent due to its ability to cause epidemic outbreaks of plague disease in animals and humans with high mortality. Plague infections elicit strong humoral immune responses against the capsular antigen (fraction 1 [F1]) of Y. pestis, and F1-specific antibodies provide protective immunity. Here we asked whether Y. pestis generates mutations that enable bacterial escape from protective immunity and isolated a variant with an IS1541 insertion in caf1A encoding the F1 outer membrane usher. The caf1A::IS1541 insertion prevented assembly of F1 pili and provided escape from plague immunity via F1-specific antibodies without a reduction in virulence in mouse models of bubonic or pneumonic plague. F1-specific antibodies interfere with Y. pestis type III transport of effector proteins into host cells, an inhibitory effect that was overcome by the caf1A::IS1541 insertion. These findings suggest a model in which IS1541 insertion into caf1A provides for reversible changes in envelope structure, enabling Y. pestis to escape from adaptive immune responses and plague immunity.

  8. Evidence of Yersinia pestis DNA from fleas in an endemic plague area of Zambia

    Directory of Open Access Journals (Sweden)

    Hang'ombe Bernard M

    2012-01-01

    Full Text Available Abstract Background Yersinia pestis is a bacterium that causes plague which infects a variety of mammals throughout the world. The disease is usually transmitted among wild rodents through a flea vector. The sources and routes of transmission of plague are poorly researched in Africa, yet remains a concern in several sub-Saharan countries. In Zambia, the disease has been reported on annual basis with up to 20 cases per year, without investigating animal reservoirs or vectors that may be responsible in the maintenance and propagation of the bacterium. In this study, we undertook plague surveillance by using PCR amplification of the plasminogen activator gene in fleas. Findings Xenopsylla species of fleas were collected from 83 rodents trapped in a plague endemic area of Zambia. Of these rodents 5 had fleas positive (6.02% for Y. pestis plasminogen activator gene. All the Y. pestis positive rodents were gerbils. Conclusions We conclude that fleas may be responsible in the transmission of Y. pestis and that PCR may provide means of plague surveillance in the endemic areas of Zambia.

  9. Current Perspectives on Plague Vector Control in Madagascar: Susceptibility Status of Xenopsylla cheopis to 12 Insecticides.

    Directory of Open Access Journals (Sweden)

    Adélaïde Miarinjara

    2016-02-01

    Full Text Available Plague is a rodent disease transmissible to humans by infected flea bites, and Madagascar is one of the countries with the highest plague incidence in the world. This study reports the susceptibility of the main plague vector Xenopsylla cheopis to 12 different insecticides belonging to 4 insecticide families (carbamates, organophosphates, pyrethroids and organochlorines. Eight populations from different geographical regions of Madagascar previously resistant to deltamethrin were tested with a World Health Organization standard bioassay. Insecticide susceptibility varied amongst populations, but all of them were resistant to six insecticides belonging to pyrethroid and carbamate insecticides (alphacypermethrin, lambdacyhalothrin, etofenprox, deltamethrin, bendiocarb and propoxur. Only one insecticide (dieldrin was an efficient pulicide for all flea populations. Cross resistances were suspected. This study proposes at least three alternative insecticides (malathion, fenitrothion and cyfluthrin to replace deltamethrin during plague epidemic responses, but the most efficient insecticide may be different for each population studied. We highlight the importance of continuous insecticide susceptibility surveillance in the areas of high plague risk in Madagascar.

  10. Modeling the epidemiological history of plague in Central Asia: Palaeoclimatic forcing on a disease system over the past millennium

    Directory of Open Access Journals (Sweden)

    Kausrud Kyrre

    2010-08-01

    Full Text Available Abstract Background Human cases of plague (Yersinia pestis infection originate, ultimately, in the bacterium's wildlife host populations. The epidemiological dynamics of the wildlife reservoir therefore determine the abundance, distribution and evolution of the pathogen, which in turn shape the frequency, distribution and virulence of human cases. Earlier studies have shown clear evidence of climatic forcing on contemporary plague abundance in rodents and humans. Results We find that high-resolution palaeoclimatic indices correlate with plague prevalence and population density in a major plague host species, the great gerbil (Rhombomys opimus, over 1949-1995. Climate-driven models trained on these data predict independent data on human plague cases in early 20th-century Kazakhstan from 1904-1948, suggesting a consistent impact of climate on large-scale wildlife reservoir dynamics influencing human epidemics. Extending the models further back in time, we also find correspondence between their predictions and qualitative records of plague epidemics over the past 1500 years. Conclusions Central Asian climate fluctuations appear to have had significant influences on regional human plague frequency in the first part of the 20th century, and probably over the past 1500 years. This first attempt at ecoepidemiological reconstruction of historical disease activity may shed some light on how long-term plague epidemiology interacts with human activity. As plague activity in Central Asia seems to have followed climate fluctuations over the past centuries, we may expect global warming to have an impact upon future plague epidemiology, probably sustaining or increasing plague activity in the region, at least in the rodent reservoirs, in the coming decades. See commentary: http://www.biomedcentral.com/1741-7007/8/108

  11. Modeling the epidemiological history of plague in Central Asia: Palaeoclimatic forcing on a disease system over the past millennium

    Science.gov (United States)

    2010-01-01

    Background Human cases of plague (Yersinia pestis) infection originate, ultimately, in the bacterium's wildlife host populations. The epidemiological dynamics of the wildlife reservoir therefore determine the abundance, distribution and evolution of the pathogen, which in turn shape the frequency, distribution and virulence of human cases. Earlier studies have shown clear evidence of climatic forcing on contemporary plague abundance in rodents and humans. Results We find that high-resolution palaeoclimatic indices correlate with plague prevalence and population density in a major plague host species, the great gerbil (Rhombomys opimus), over 1949-1995. Climate-driven models trained on these data predict independent data on human plague cases in early 20th-century Kazakhstan from 1904-1948, suggesting a consistent impact of climate on large-scale wildlife reservoir dynamics influencing human epidemics. Extending the models further back in time, we also find correspondence between their predictions and qualitative records of plague epidemics over the past 1500 years. Conclusions Central Asian climate fluctuations appear to have had significant influences on regional human plague frequency in the first part of the 20th century, and probably over the past 1500 years. This first attempt at ecoepidemiological reconstruction of historical disease activity may shed some light on how long-term plague epidemiology interacts with human activity. As plague activity in Central Asia seems to have followed climate fluctuations over the past centuries, we may expect global warming to have an impact upon future plague epidemiology, probably sustaining or increasing plague activity in the region, at least in the rodent reservoirs, in the coming decades. See commentary: http://www.biomedcentral.com/1741-7007/8/108 PMID:20799946

  12. The plague of Thebes, a historical epidemic in Sophocles' Oedipus Rex.

    Science.gov (United States)

    Kousoulis, Antonis A; Economopoulos, Konstantinos P; Poulakou-Rebelakou, Effie; Androutsos, George; Tsiodras, Sotirios

    2012-01-01

    Sophocles, one of the most noted playwrights of the ancient world, wrote the tragedy Oedipus Rex in the first half of the decade 430-420 bc. A lethal plague is described in this drama. We adopted a critical approach to Oedipus Rex in analyzing the literary description of the disease, unraveling its clinical features, and defining a possible underlying cause. Our goals were to clarify whether the plague described in Oedipus Rex reflects an actual historical event; to compare it with the plague of Athens, which was described by Thucydides as occurring around the same time Sophocles wrote; and to propose a likely causative pathogen. A critical reading of Oedipus Rex and a comparison with Thucydides' history, as well as a systematic review of historical data, strongly suggests that this epidemic was an actual event, possibly caused by Brucella abortus.

  13. The Plague of Thebes, a Historical Epidemic in Sophocles’ Oedipus Rex

    Science.gov (United States)

    Economopoulos, Konstantinos P.; Poulakou-Rebelakou, Effie; Androutsos, George; Tsiodras, Sotirios

    2012-01-01

    Sophocles, one of the most noted playwrights of the ancient world, wrote the tragedy Oedipus Rex in the first half of the decade 430–420 bc. A lethal plague is described in this drama. We adopted a critical approach to Oedipus Rex in analyzing the literary description of the disease, unraveling its clinical features, and defining a possible underlying cause. Our goals were to clarify whether the plague described in Oedipus Rex reflects an actual historical event; to compare it with the plague of Athens, which was described by Thucydides as occurring around the same time Sophocles wrote; and to propose a likely causative pathogen. A critical reading of Oedipus Rex and a comparison with Thucydides’ history, as well as a systematic review of historical data, strongly suggests that this epidemic was an actual event, possibly caused by Brucella abortus. PMID:22261081

  14. Diagnosis of plague and identification of virulence markers in Yersinia pestis by multiplex-PCR

    Directory of Open Access Journals (Sweden)

    LEAL Nilma C.

    1999-01-01

    Full Text Available We have developed a procedure for the rapid diagnosis of plague that also allows the identification of prominent virulence markers of Y. pestis strains. This procedure is based upon the use of a single polymerase chain reaction with multiple pairs of primers directed at genes present in the three virulence plasmids as well as in the chromosomal pathogenicity island of the bacterium. The technique allowed the discrimination of strains which lacked one or more of the known pathogenic loci, using as template total DNA obtained from bacterial cultures and from simulated blood cultures containing diluted concentration of bacteria. It also proved effective in confirming the disease in a blood culture from a plague suspected patient. As the results are obtained in a few hours this technique will be useful in the methodology of the Plague Control Program.

  15. Plant-made subunit vaccine against pneumonic and bubonic plague is orally immunogenic in mice.

    Science.gov (United States)

    Alvarez, M Lucrecia; Pinyerd, Heidi L; Crisantes, Jason D; Rigano, M Manuela; Pinkhasov, Julia; Walmsley, Amanda M; Mason, Hugh S; Cardineau, Guy A

    2006-03-24

    Yersinia pestis, the causative agent of plague, is an extremely virulent bacterium but there are no approved vaccines for protection against it. Our goal was to produce a vaccine that would address: ease of delivery, mucosal efficacy, safety, rapid scalability, and cost. We developed a novel production and delivery system for a plague vaccine of a Y. pestis F1-V antigen fusion protein expressed in tomato. Immunogenicity of the F1-V transgenic tomatoes was confirmed in mice that were primed subcutaneously with bacterially-produced F1-V and boosted orally with transgenic tomato fruit. Expression of the plague antigens in fruit allowed producing an oral vaccine candidate without protein purification and with minimal processing technology.

  16. Electron and scanning probe microscopy study of S-layers of plague microbes

    Science.gov (United States)

    Konnov, Nikolai P.; Baiburin, Vil B.; Djatlov, Ivan A.; Antonova, Oksana A.; Volkov, Uryi P.

    1999-01-01

    Microscopy investigations of S-layers of plague microbes have been carried out. A protein forming S-layer was isolated, purified and its biochemical properties were studied. Images of plague cells with and without S-layer and images of isolated S-layer protein arrays on solid supports were obtained by transmission electron microscopy. An isolated protein forming the layer is self-assembled into crystalline structure with hexagonal pores are of regular size about 4 - 8 nm, which was observed by transmission electron micrographs. The STM images of plague microbes with S-layer and without one and the STM and AFM images of isolated S-layer protein arrays on mica surface were obtained.

  17. Investigation of and Response to 2 Plague Cases, Yosemite National Park, California, USA, 2015.

    Science.gov (United States)

    Danforth, Mary; Novak, Mark; Petersen, Jeannine; Mead, Paul; Kingry, Luke; Weinburke, Matthew; Buttke, Danielle; Hacker, Gregory; Tucker, James; Niemela, Michael; Jackson, Bryan; Padgett, Kerry; Liebman, Kelly; Vugia, Duc; Kramer, Vicki

    2016-12-01

    In August 2015, plague was diagnosed for 2 persons who had visited Yosemite National Park in California, USA. One case was septicemic and the other bubonic. Subsequent environmental investigation identified probable locations of exposure for each patient and evidence of epizootic plague in other areas of the park. Transmission of Yersinia pestis was detected by testing rodent serum, fleas, and rodent carcasses. The environmental investigation and whole-genome multilocus sequence typing of Y. pestis isolates from the patients and environmental samples indicated that the patients had been exposed in different locations and that at least 2 distinct strains of Y. pestis were circulating among vector-host populations in the area. Public education efforts and insecticide applications in select areas to control rodent fleas probably reduced the risk for plague transmission to park visitors and staff.

  18. Post-epizootic surveys of waterfowl for duck plague (duck virus enteritis)

    Science.gov (United States)

    Brand, C.J.; Docherty, D.E.

    1988-01-01

    Surviving birds from nine duck plague outbreaks in urban and confined waterfowl were sampled for duck plague (DP) virus and DP antibody during 1979-86. Duck plague virus was found in combined oral and cloacal swabs of birds from three outbreaks, and DP-neutralizing antibody was demonstrated in some birds from all nine outbreaks. Greater prevalence of DP antibody and higher titers were found in survivors from confined populations than from free-flying urban populations. Free-flying waterfowl from within 52 km of four DP outbreak sites were also sampled; virus was not found in any birds, but DP antibody was found in urban waterfowl in the vicinity of an outbreak in Potterville, Michigan. No evidence of exposure to or shedding of DP virus in migratory waterfowl was found in two regions where DP appears enzootic in urban and confined waterfowl (Eastern Shore of Maryland and the vicinity of Sacramento, California).

  19. Further development of raccoon poxvirus-vectored vaccines against plague (Yersinia pestis)

    Science.gov (United States)

    Rocke, T.E.; Iams, Keith P.; Dawe, S.; Smith, S.R.; Williamson, J.L.; Heisey, D.M.; Osorio, J.E.

    2009-01-01

    In previous studies, we demonstrated protection against plague in mice and prairie dogs using a raccoon pox (RCN) virus-vectored vaccine that expressed the F1 capsular antigen of Yersinia pestis. In order to improve vaccine efficacy, we have now constructed additional RCN-plague vaccines containing two different forms of the lcrV (V) gene, including full-length (Vfull) and a truncated form (V307). Mouse challenge studies with Y. pestis strain CO92 showed that vaccination with a combination of RCN-F1 and the truncated V construct (RCN-V307) provided the greatest improvement (P = 0.01) in protection against plague over vaccination with RCN-F1 alone. This effect was mediated primarily by anti-F1 and anti-V antibodies and both contributed independently to increased survival of vaccinated mice.

  20. [A NATURAL PLAGUE FOCUS. IN GORNYI ALTAI: FORMATION, DEVELOPMENT, AND FUNCTIONING].

    Science.gov (United States)

    Korzun, V M; Balakhoiov, S V; Chpanin, E V; Denisov, A V; Mikhailov, E P; Mischenko, A J; Yarygina, M B; Rozhdestvensky, E N; Fomina, L A

    2016-01-01

    The paper gives the results of analyzing the data of long-term studies of the natural focal pattern of plague in the Gornyi Altai natural focus. It describes a wide range of biological processes occurring in the focus and shows the most important patterns of its functioning as a complex multilevel ecological system. The key features of the formation of the focus have been revealed. The plague focus in South-Western Altai has formed relatively, recently, about half a century ago, then it has intensively developed and its enzootic area and the activity of epizootic manifestations have considerably increased. This process is due to the space-time transformations of the basic ecological and population characteristics of Pallas' pika (Ochotoma pallasi), the principal vector of the pathogen of plague and fleas parasitizing the mammal, which is in turn related to the aridization of mountain steppes in South-Western Altai.

  1. [Origin of the plague microbe Yersinia pestis: structure of the process of speciation].

    Science.gov (United States)

    Suntsov, V V

    2012-01-01

    The origin and evolution of the plague microbe Yersinia pestis are considered in the context of propositions of modern Darwinism. It was shown that the plague pathogen diverged from the pseudotuberculous microbe Yersinia pseudotuberculosis O:1b in the mountain steppe landscapes of Central Asia in the Sartan: 22000-15000 years ago. Speciation occurred in the tarbagan (Marmota sibirica)--flea (Oropsylla silantiewi) parasitic system. The structure of the speciation process included six stages: isolation, genetic drift, enhancement of intrapopulational polymorphism, the beginning of pesticin synthesis (genetic conflict and emergence of hiatus), specialization (stabilization of characteristics), and adaptive irradiation (transformation of the monotypic species Y. pestis tarbagani into a polytypic species). The scenario opens up wide prospects for construction of the molecular phylogeny of the plague microbe Y. pestis and for investigation of the biochemical and molecular-genetic aspects of "Darwinian" evolution of pathogens from many other nature-focal infections.

  2. Demographic and spatio-temporal variation in human plague at a persistent focus in Tanzania

    DEFF Research Database (Denmark)

    Davis, S; Makundi, R H; Machang'u, R S

    2006-01-01

    Human plague in the Western Usambara Mountains in Tanzania has been a public health problem since the first outbreak in 1980. The wildlife reservoir is unknown and eradication measures that have proved effective elsewhere in Tanzania appear to fail in this region. We use census data from 2002...... and hospital records kept since 1986 to describe the temporal, spatial and demographic variation in human plague. A seasonal peak in cases occurs from December to February with the numbers of cases during this peak varying between 0 and 1150. Variation in incidence, calculated for each village as the mean...... number of cases per thousand inhabitants per year, indicates that human plague is concentrated around a group of three neighbouring, relatively isolated, high-altitude villages; Nywelo, Madala and Gologolo. However, there was no evidence that these villages were acting as a source of infection...

  3. Seroprevalence of hantavirus and Yersinia pestis antibodies in professionals from the Plague Control Program

    Directory of Open Access Journals (Sweden)

    Erika de Cassia Vieira da Costa

    2013-07-01

    Full Text Available Introduction Professionals who handle rodents in the field and in the laboratory are at risk of infection by the microorganisms harbored by these animals. Methods Serum samples from professionals involved in rodent and Yersinia pestis handling in field or laboratory work were analyzed to determine hantavirus and plague seroprevalence and to establish a relationship between these activities and reports of illnesses. Results Two individuals had antibodies against hantavirus, and two harbored antibodies against the plague; none of the individuals had experienced an illness related to their duties. Conclusions These results confirm the risks of hantavirus- and plague-related field and laboratory activities and the importance of protective measures for such work.

  4. Findings of bacterial microflora in piglets infected with conventional swine plague

    Directory of Open Access Journals (Sweden)

    Prodanov Jasna

    2002-01-01

    Full Text Available Piglets infected with the conventional swine plague virus as a result of secondary bacterial infections sometimes show an insufficiently clear clinical and pathoanatomical picture, which is why the very procedure of diagnosis is complex and the final diagnosis unreliable. That is why these investigations were aimed at examining the presence of bacterial microflora in diseased and dead pilgets which were found to have the viral antigen for CSP using the fluorescent antibody technique, in cases where the pathomorphological finding was not characteristic for conventional swine plague. Autopsies of dead piglets most often showed changes in the digestive tract and lungs, with resulting technopathy and diseases of infective nature. Such findings on knowledge of a present bacterial microflora are especially important in cases when conventional swine plague is controlled on farms and an announcement that the disease has been contained is in the offing.

  5. Development and testing of a rapid diagnostic test for bubonic and pneumonic plague.

    Science.gov (United States)

    Chanteau, Suzanne; Rahalison, Lila; Ralafiarisoa, Lalao; Foulon, Jeanine; Ratsitorahina, Mahery; Ratsifasoamanana, Lala; Carniel, Elisabeth; Nato, Farida

    2003-01-18

    Plague is often fatal without prompt and appropriate treatment. It affects mainly poor and remote populations. Late diagnosis is one of the major causes of human death and spread of the disease, since it limits the effectiveness of control measures. We aimed to develop and assess a rapid diagnostic test (RDT) for plague. We developed a test that used monoclonal antibodies to the F1 antigen of Yersinia pestis. Sensitivity and specificity were assessed with a range of bacterial cultures and clinical samples, and compared with findings from available ELISA and bacteriological tests for plague. Samples from patients thought to have plague were tested with the RDT in the laboratory and by health workers in 26 pilot sites in Madagascar. The RDT detected concentrations of F1 antigen as low as 0.5 ng/mL in up to 15 min, and had a shelf life of 21 days at 60 degrees C. Its sensitivity and specificity were both 100%. RDT detected 41.6% and 31% more positive clinical specimens than did bacteriological methods and ELISA, respectively. The agreement rate between tests done at remote centres and in the laboratory was 89.8%. With the combination of bacteriological methods and F1 ELISA as reference standard, the positive and negative predictive values of the RDT were 90.6% and 86.7%, respectively. Our RDT is a specific, sensitive, and reliable test that can easily be done by health workers at the patient's bedside, for the rapid diagnosis of pneumonic and bubonic plague. This test will be of key importance for the control of plague in endemic countries.

  6. An encapsulated Yersinia pseudotuberculosis is a highly efficient vaccine against pneumonic plague.

    Science.gov (United States)

    Derbise, Anne; Cerdà Marín, Alba; Ave, Patrick; Blisnick, Thierry; Huerre, Michel; Carniel, Elisabeth; Demeure, Christian E

    2012-01-01

    Plague is still a public health problem in the world and is re-emerging, but no efficient vaccine is available. We previously reported that oral inoculation of a live attenuated Yersinia pseudotuberculosis, the recent ancestor of Yersinia pestis, provided protection against bubonic plague. However, the strain poorly protected against pneumonic plague, the most deadly and contagious form of the disease, and was not genetically defined. The sequenced Y. pseudotuberculosis IP32953 has been irreversibly attenuated by deletion of genes encoding three essential virulence factors. An encapsulated Y. pseudotuberculosis was generated by cloning the Y. pestis F1-encoding caf operon and expressing it in the attenuated strain. The new V674pF1 strain produced the F1 capsule in vitro and in vivo. Oral inoculation of V674pF1 allowed the colonization of the gut without lesions to Peyer's patches and the spleen. Vaccination induced both humoral and cellular components of immunity, at the systemic (IgG and Th1 cells) and the mucosal levels (IgA and Th17 cells). A single oral dose conferred 100% protection against a lethal pneumonic plague challenge (33×LD(50) of the fully virulent Y. pestis CO92 strain) and 94% against a high challenge dose (3,300×LD(50)). Both F1 and other Yersinia antigens were recognized and V674pF1 efficiently protected against a F1-negative Y. pestis. The encapsulated Y. pseudotuberculosis V674pF1 is an efficient live oral vaccine against pneumonic plague, and could be developed for mass vaccination in tropical endemic areas to control pneumonic plague transmission and mortality.

  7. Spatiotemporal modelling and mapping of the bubonic plague epidemic in India.

    Science.gov (United States)

    Yu, Hwa-Lung; Christakos, George

    2006-03-17

    This work studies the spatiotemporal evolution of bubonic plague in India during 1896-1906 using stochastic concepts and geographical information science techniques. In the past, most investigations focused on selected cities to conduct different kinds of studies, such as the ecology of rats. No detailed maps existed incorporating the space-time dependence structure and uncertainty sources of the epidemic system and providing a composite space-time picture of the disease propagation characteristics. Informative spatiotemporal maps were generated that represented mortality rates and geographical spread of the disease, and epidemic indicator plots were derived that offered meaningful characterizations of the spatiotemporal disease distribution. The bubonic plague in India exhibited strong seasonal and geographical features. During its entire duration, the plague continued to invade new geographical areas, while it followed a re-emergence pattern at many localities; its rate changed significantly during each year and the mortality distribution exhibited space-time heterogeneous patterns; prevalence usually occurred in the autumn and spring, whereas the plague stopped moving towards new locations during the summers. Modern stochastic modelling and geographical information science provide powerful means to study the spatiotemporal distribution of the bubonic plague epidemic under conditions of uncertainty and multi-sourced databases; to account for various forms of interdisciplinary knowledge; and to generate informative space-time maps of mortality rates and propagation patterns. To the best of our knowledge, this kind of plague maps and plots become available for the first time, thus providing novel perspectives concerning the distribution and space-time propagation of the deadly epidemic. Furthermore, systematic maps and indicator plots make possible the comparison of the spatial-temporal propagation patterns of different diseases.

  8. Model-based analysis of an outbreak of bubonic plague in Cairo in 1801.

    Science.gov (United States)

    Didelot, Xavier; Whittles, Lilith K; Hall, Ian

    2017-06-01

    Bubonic plague has caused three deadly pandemics in human history: from the mid-sixth to mid-eighth century, from the mid-fourteenth to the mid-eighteenth century and from the end of the nineteenth until the mid-twentieth century. Between the second and the third pandemics, plague was causing sporadic outbreaks in only a few countries in the Middle East, including Egypt. Little is known about this historical phase of plague, even though it represents the temporal, geographical and phylogenetic transition between the second and third pandemics. Here we analysed in detail an outbreak of plague that took place in Cairo in 1801, and for which epidemiological data are uniquely available thanks to the presence of medical officers accompanying the Napoleonic expedition into Egypt at that time. We propose a new stochastic model describing how bubonic plague outbreaks unfold in both rat and human populations, and perform Bayesian inference under this model using a particle Markov chain Monte Carlo. Rat carcasses were estimated to be infectious for approximately 4 days after death, which is in good agreement with local observations on the survival of infectious rat fleas. The estimated transmission rate between rats implies a basic reproduction number R0 of approximately 3, causing the collapse of the rat population in approximately 100 days. Simultaneously, the force of infection exerted by each infected rat carcass onto the human population increases progressively by more than an order of magnitude. We also considered human-to-human transmission via pneumonic plague or human specific vectors, but found this route to account for only a small fraction of cases and to be significantly below the threshold required to sustain an outbreak. © 2017 The Author(s).

  9. 圣经中的鼠疫及纪年%Plague and Its Time in Bible

    Institute of Scientific and Technical Information of China (English)

    马学博

    2015-01-01

    圣经记载了最早一次鼠疫流行,西方学者为此长期争论不休,主要集中在临床症状的译名、宿主动物黑鼠是否存在等,而发生鼠疫流行的年代则语焉不详。现据文献研究及考古发掘证据,试图阐释“非利士人鼠疫”的可信性,提出相对准确的纪年约为公元前1050年,并且涉及了旧约时代中东鼠疫自然疫源地及鼠疫流行史研究与鼠疫实验科学研究关系问题。%The first plague epidemic was recorded in the Bible. Western scholars debated about it for a long time, focusing mainly in the translation of clinical symptoms, the presence of host animal rattus, and so on. However, the time of plague epidemic was vague. According to the evidence of literature research and archaeological excavations, the article attempted to explain the credibility of 'Philistine plague', and proposed that the relatively accurate time of plague epidemic is 1050 BC. At the same time, the article involved in the Old Testament times' natural foci of plague in the Near East, and the relation of study of the history of the plague epidemic and experimental scientific research.

  10. An Encapsulated Yersinia pseudotuberculosis Is a Highly Efficient Vaccine against Pneumonic Plague

    Science.gov (United States)

    Derbise, Anne; Cerdà Marín, Alba; Ave, Patrick; Blisnick, Thierry; Huerre, Michel; Carniel, Elisabeth; Demeure, Christian E.

    2012-01-01

    Background Plague is still a public health problem in the world and is re-emerging, but no efficient vaccine is available. We previously reported that oral inoculation of a live attenuated Yersinia pseudotuberculosis, the recent ancestor of Yersinia pestis, provided protection against bubonic plague. However, the strain poorly protected against pneumonic plague, the most deadly and contagious form of the disease, and was not genetically defined. Methodology and Principal Findings The sequenced Y. pseudotuberculosis IP32953 has been irreversibly attenuated by deletion of genes encoding three essential virulence factors. An encapsulated Y. pseudotuberculosis was generated by cloning the Y. pestis F1-encoding caf operon and expressing it in the attenuated strain. The new V674pF1 strain produced the F1 capsule in vitro and in vivo. Oral inoculation of V674pF1 allowed the colonization of the gut without lesions to Peyer's patches and the spleen. Vaccination induced both humoral and cellular components of immunity, at the systemic (IgG and Th1 cells) and the mucosal levels (IgA and Th17 cells). A single oral dose conferred 100% protection against a lethal pneumonic plague challenge (33×LD50 of the fully virulent Y. pestis CO92 strain) and 94% against a high challenge dose (3,300×LD50). Both F1 and other Yersinia antigens were recognized and V674pF1 efficiently protected against a F1-negative Y. pestis. Conclusions and Significance The encapsulated Y. pseudotuberculosis V674pF1 is an efficient live oral vaccine against pneumonic plague, and could be developed for mass vaccination in tropical endemic areas to control pneumonic plague transmission and mortality. PMID:22348169

  11. Observations on the epidemiology of plague in Tanzania during the period 1974-1988.

    Science.gov (United States)

    Kilonzo, B S

    1992-09-01

    Field and commensal rodents and shrews were live-trapped from selected areas in each of the six zones of the Republic, namely North-eastern, Eastern, Central-western, South-western, Southern and Seaports. The captured animals, small ruminants, humans and small carnivores were serologically tested for specific plague antibodies, using the Passive haemagglutination (PHA) and Passive haemagglutination Inhibition (PHAI) techniques. Taxonomic studies and population densities of rodents and their ectoparasasites were carried out. A total of 5638 animals were captured and 79.9% of them were tested for plague. Of those tested, 2.4% contained agglutinating plague antibodies at serum dilutions of 1:20 and above. The positive rodents were found in Lushoto, Mbulu, Chunya and Monduli districts, as well as at Tanga seaport. These include R. rattus, M. natalensis, A. niloticus and Otomys spp. A total of 7480 human, 293 carnivorous and 425 small ruminant sera were also tested for plague. Seven (2.4%) of the carnivores were positive at serum titres of 1:20-1:80. All the small ruminants were negative. Likewise, 1.4% of the tested human sera contained specific plague antibodies at titres ranging from 1:20-1:60. Out of 6480 fleas collected from the captured small mammals, 5476 were identified. Of these, 34.5%, 20.4%, and 17.8% were X. brasiliensis, D. lypusus and X. cheopis respectively. It was generally concluded that plague was still endemic in several parts of the country, that some foci were active, and that there was a potential risk of accidental introduction and/or transfer of the disease into or out of the country. Establishment and maintenance of surveillance services and facilitating research and control programmes of the disease were recommended.

  12. [Preventive measures against plague and the control of Chinese coolies in colonial Korea].

    Science.gov (United States)

    Kim, Youngsoo

    2014-12-01

    This paper aims to examine the preventive measures taken against the plague in colonial Korea, particularly as applied to the control of Chinese coolies in 1911, soon after the annexation. The Government General of Korea began preventive measures with a train quarantine in Shin'uiju and Incheon in response to the spread of the plague to the Southern Manchuria. Shin' uiju had become urbanized due the development of the transportation network, and the seaport of Incheon was the major hub for traffic with China. Examining the transportation routes for the entry and exit of Chinese to and from Korea makes clear the reason why the Korea Government General initiated preventive measures in mid-January, 1911. The Government General of Korea tried to block the entry of Chinese through the land border crossing with China and through ports of entry, primarily Incheon. During the implementation of the preventive measures, quarantine facilities were built, including a quarantine station and isolation facility in Incheon. It was also needed to investigate the population and residential locations of Chinese in Korea to prevent the spread of plague. A certificate of residence was issued to all Chinese in Korea, which they needed to carry when they travelled. The preventive measures against plague which broke out in Manchuria were removed gradually. However, there was no specific measures against Chinese coolies, those who had migrated from China to work in the spring in Korea. Still the Government General of Korea had doubt about an infection of the respiratory system. As a result, the labor market in colonial Korea underwent changes in this period. The Government General recruited Korean laborers, instead of Chinese coolies whose employment had been planned. This move explains the Government General's strong preventive measures against plague and uncertainty in the route of plague infection, which influenced subsequent regulations on the prohibition of Chinese coolies working on

  13. Spatiotemporal modelling and mapping of the bubonic plague epidemic in India

    Directory of Open Access Journals (Sweden)

    Christakos George

    2006-03-01

    Full Text Available Abstract Background This work studies the spatiotemporal evolution of bubonic plague in India during 1896–1906 using stochastic concepts and geographical information science techniques. In the past, most investigations focused on selected cities to conduct different kinds of studies, such as the ecology of rats. No detailed maps existed incorporating the space-time dependence structure and uncertainty sources of the epidemic system and providing a composite space-time picture of the disease propagation characteristics. Results Informative spatiotemporal maps were generated that represented mortality rates and geographical spread of the disease, and epidemic indicator plots were derived that offered meaningful characterizations of the spatiotemporal disease distribution. The bubonic plague in India exhibited strong seasonal and geographical features. During its entire duration, the plague continued to invade new geographical areas, while it followed a re-emergence pattern at many localities; its rate changed significantly during each year and the mortality distribution exhibited space-time heterogeneous patterns; prevalence usually occurred in the autumn and spring, whereas the plague stopped moving towards new locations during the summers. Conclusion Modern stochastic modelling and geographical information science provide powerful means to study the spatiotemporal distribution of the bubonic plague epidemic under conditions of uncertainty and multi-sourced databases; to account for various forms of interdisciplinary knowledge; and to generate informative space-time maps of mortality rates and propagation patterns. To the best of our knowledge, this kind of plague maps and plots become available for the first time, thus providing novel perspectives concerning the distribution and space-time propagation of the deadly epidemic. Furthermore, systematic maps and indicator plots make possible the comparison of the spatial-temporal propagation

  14. An encapsulated Yersinia pseudotuberculosis is a highly efficient vaccine against pneumonic plague.

    Directory of Open Access Journals (Sweden)

    Anne Derbise

    Full Text Available BACKGROUND: Plague is still a public health problem in the world and is re-emerging, but no efficient vaccine is available. We previously reported that oral inoculation of a live attenuated Yersinia pseudotuberculosis, the recent ancestor of Yersinia pestis, provided protection against bubonic plague. However, the strain poorly protected against pneumonic plague, the most deadly and contagious form of the disease, and was not genetically defined. METHODOLOGY AND PRINCIPAL FINDINGS: The sequenced Y. pseudotuberculosis IP32953 has been irreversibly attenuated by deletion of genes encoding three essential virulence factors. An encapsulated Y. pseudotuberculosis was generated by cloning the Y. pestis F1-encoding caf operon and expressing it in the attenuated strain. The new V674pF1 strain produced the F1 capsule in vitro and in vivo. Oral inoculation of V674pF1 allowed the colonization of the gut without lesions to Peyer's patches and the spleen. Vaccination induced both humoral and cellular components of immunity, at the systemic (IgG and Th1 cells and the mucosal levels (IgA and Th17 cells. A single oral dose conferred 100% protection against a lethal pneumonic plague challenge (33×LD(50 of the fully virulent Y. pestis CO92 strain and 94% against a high challenge dose (3,300×LD(50. Both F1 and other Yersinia antigens were recognized and V674pF1 efficiently protected against a F1-negative Y. pestis. CONCLUSIONS AND SIGNIFICANCE: The encapsulated Y. pseudotuberculosis V674pF1 is an efficient live oral vaccine against pneumonic plague, and could be developed for mass vaccination in tropical endemic areas to control pneumonic plague transmission and mortality.

  15. Age at vaccination may influence response to sylvatic plague vaccine (SPV) in Gunnison’s prairie dogs (Cynomys gunnisoni)

    Science.gov (United States)

    Rocke, Tonie E.; Tripp, Daniel W.; Lorenzsonn, Faye; Falendysz, Elizabeth A.; Smith, Susan; Williamson, Judy L.; Abbott, Rachel C.

    2015-01-01

    Gunnison’s prairie dogs (Cynomys gunnisoni) have been considered at greater risk from Yersinia pestis (plague) infection in the montane portion of their range compared to populations at lower elevations, possibly due to factors related to flea transmission of the bacteria or greater host susceptibility. To test the latter hypothesis and determine whether vaccination against plague with an oral sylvatic plague vaccine (SPV) improved survival, we captured prairie dogs from a C. g. gunnisoni or “montane” population and a C. g. zuniensis or “prairie” population for vaccine efficacy and challenge studies. No differences (P = 0.63) were found in plague susceptibility in non-vaccinated animals between these two populations; however, vaccinates from the prairie population survived plague challenge at significantly higher rates (P Vaccinates that were juveniles or young adults survived plague challenge at a much higher rate than adults (P < 0.01 and P = 0.02, respectively), but no difference (P = 0.83) was detected in survival rates between control animals of different ages. These results suggest that host susceptibility is probably not related to the assumed greater risk from plague in the C. g. gunnisoni or “montane” populations of Gunnison’s prairie dogs, and that SPV could be a useful plague management tool for this species, particularly if targeted at younger cohorts.

  16. Spatial distribution patterns of plague hosts : point pattern analysis of the burrows of great gerbils in Kazakhstan

    NARCIS (Netherlands)

    Wilschut, Liesbeth I|info:eu-repo/dai/nl/344842304; Laudisoit, Anne; Hughes, Nelika K; Addink, Elisabeth A|info:eu-repo/dai/nl/224281216; de Jong, Steven M|info:eu-repo/dai/nl/120221306; Heesterbeek, Hans A P|info:eu-repo/dai/nl/073321427; Reijniers, Jonas; Eagle, Sally; Dubyanskiy, Vladimir M; Begon, Mike

    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

  17. Spatial analysis and identification of high risk plague regions in Pakistan based on associated rodent species distribution.

    Science.gov (United States)

    Shabbir, Madiha; Aleem, Maha; Javed, Sundus; Wagner, David M; Keim, Paul S; Eqani, Syed Ali Musstjab Akbar Shah; Bokhari, Habib

    2016-01-01

    Plague, caused by Yersinia pestitis, is an infectious bacterial disease that has a high fatality rate if untreated. Rodents are plague reservoirs and play an important role in disease spread. Plague cases have been reported extensively since the second pandemic from the 14th century in countries sharing borders with Pakistan, such as China and India, as well as nearby countries including Russia and central Asia. Despite being centrally located in a plague-infested geographical zone, there has been no plague incidence reported from Pakistan. This study aims to pinpoint some of the potentially important aspects of the disease, which have to be considered when assessing potential risk associated with a plague outbreak in Pakistan. In this context, the occurrence and distribution of plague-associated rodent reservoirs in different regions of Pakistan in relation to those found in the neighboring countries were mapped. In addition, the climatic factors that may also influence disease spread by affecting the growth of the bacteria are also discussed. The combined epidemiological and ecological surveillance studies suggest a prevalence of several potential rodent carriers in certain districts with the possibility of a plague outbreak in Pakistan.

  18. Age at Vaccination May Influence Response to Sylvatic Plague Vaccine (SPV) in Gunnison's Prairie Dogs (Cynomys gunnisoni).

    Science.gov (United States)

    Rocke, Tonie E; Tripp, Dan; Lorenzsonn, Faye; Falendysz, Elizabeth; Smith, Susan; Williamson, Judy; Abbott, Rachel

    2015-06-01

    Gunnison's prairie dogs (Cynomys gunnisoni) have been considered at greater risk from Yersinia pestis (plague) infection in the montane portion of their range compared to populations at lower elevations, possibly due to factors related to flea transmission of the bacteria or greater host susceptibility. To test the latter hypothesis and determine whether vaccination against plague with an oral sylvatic plague vaccine (SPV) improved survival, we captured prairie dogs from a C. g. gunnisoni or "montane" population and a C. g. zuniensis or "prairie" population for vaccine efficacy and challenge studies. No differences (P = 0.63) were found in plague susceptibility in non-vaccinated animals between these two populations; however, vaccinates from the prairie population survived plague challenge at significantly higher rates (P plague challenge at a much higher rate than adults (P plague in the C. g. gunnisoni or "montane" populations of Gunnison's prairie dogs, and that SPV could be a useful plague management tool for this species, particularly if targeted at younger cohorts.

  19. Spatial distribution patterns of plague hosts : point pattern analysis of the burrows of great gerbils in Kazakhstan

    NARCIS (Netherlands)

    Wilschut, Liesbeth I|info:eu-repo/dai/nl/344842304; Laudisoit, Anne; Hughes, Nelika K; Addink, Elisabeth A|info:eu-repo/dai/nl/224281216; de Jong, Steven M|info:eu-repo/dai/nl/120221306; Heesterbeek, Hans A P|info:eu-repo/dai/nl/073321427; Reijniers, Jonas; Eagle, Sally; Dubyanskiy, Vladimir M; Begon, Mike

    2015-01-01

    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

  20. Spatial distribution patterns of plague hosts : point pattern analysis of the burrows of great gerbils in Kazakhstan

    NARCIS (Netherlands)

    Wilschut, Liesbeth I; Laudisoit, Anne; Hughes, Nelika K; Addink, Elisabeth A; de Jong, Steven M; Heesterbeek, Hans A P; Reijniers, Jonas; Eagle, Sally; Dubyanskiy, Vladimir M; Begon, Mike

    2015-01-01

    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

  1. Use of Rhodamine B as a biomarker for oral plague vaccination of prairie dogs

    Science.gov (United States)

    Fernandez, Julia Rodriguez-Ramos; Rocke, Tonie E.

    2011-01-01

    Oral vaccination against Yersinia pestis could provide a feasible approach for controlling plague in prairie dogs (Cynomys spp.) for conservation and public health purposes. Biomarkers are useful in wildlife vaccination programs to demonstrate exposure to vaccine baits. Rhodamine B (RB) was tested as a potential biomarker for oral plague vaccination because it allows nonlethal sampling of animals through hair, blood, and feces. We found that RB is an appropriate marker for bait uptake studies of C. ludovicianus) when used at concentrations 10 mg RB per kg target animal mass. Whiskers with follicles provided the best sample for RB detection.

  2. Use of rhodamine B as a biomarker for oral plague vaccination of prairie dogs.

    Science.gov (United States)

    Fernandez, Julia Rodriguez-Ramos; Rocke, Tonie E

    2011-07-01

    Oral vaccination against Yersinia pestis could provide a feasible approach for controlling plague in prairie dogs (Cynomys spp.) for conservation and public health purposes. Biomarkers are useful in wildlife vaccination programs to demonstrate exposure to vaccine baits. Rhodamine B (RB) was tested as a potential biomarker for oral plague vaccination because it allows nonlethal sampling of animals through hair, blood, and feces. We found that RB is an appropriate marker for bait uptake studies of black-tailed prairie dogs (C. ludovicianus) when used at concentrations 10 mg RB per kg target animal mass. Whiskers with follicles provided the best sample for RB detection.

  3. Socio-epidemiological determinants of 2002 plague outbreak in Himachal Pradesh, India: a qualitative study.

    Science.gov (United States)

    Goel, Sonu; Kaur, Harvinder; Gupta, Anil Kumar; Chauhan, Umesh; Singh, Amarjeet

    2014-04-08

    This qualitative investigation was conducted to determine the socio-epidemiological factors related to the plague outbreak (2002) in Himachal Pradesh (HP), India. The data for socio-epidemiological factors related to the plague outbreak (2002) in HP was obtained from residents through 150 in-depth Interviews (IDI) and 30 Focus Group Discussions (FGD) during six visits (from May 2011 to April 2012) by the research team. Natives, health officials and the nomadic population were interviewed. According to their opinion and viewpoints data was collected and their lifestyle and hunting practices were studied in detail. Tape recorders were used during various FGDs and IDIs. The interviews and FGDs were later transcribed and coded. In-depth analysis of the recorded data was done using an inductive thematic analysis approach. The study reports that the outbreak in 2002 in a few villages of Himachal Pradesh was that of plague and it occurred by the contact of an index case with wild animals after hunting and de-skinning. The first wave of plague transmission which took 16 lives of residents was followed by a second wave of transmission in a ward of a tertiary care hospital where one visitor acquired it from relatives of the index case and succumbed. The life-style practices of residents (hunting behavior, long stay in caves and jungles, overcrowding in houses, poor hygiene and sanitation, belief in 'God' and faith healers for cure of diseases) was optimal for the occurrence and rapid spread of such a communicable disease. The man-rodent contact is intensified due to the practice of hunting in such a rodent-ridden environment. The residents harbor a strong belief that plague occurs due to the wrath of gods. Various un-reported outbreaks of plague were also observed by officials, residents and old folk. The persistence of plague in HP is favoured by its hilly terrain, inaccessible areas, inclement weather (snow) in winters, unhygienic lifestyle, hunting practices of residents

  4. Transverse--Harris--lines in a skeletal population from the 1711 Danish plague site

    DEFF Research Database (Denmark)

    Fiscella, Gabriela N; Bennike, Pia; Lynnerup, Niels

    2008-01-01

    This study examines the occurrence and distribution of transverse lines in skeletal remains from the Copenhagen site, a plague cemetery dated 1711 AD. A relatively low frequency for evidence of line formation was observed in the individuals comprising the total sample and no transverse lines were...... present in the subadult category. This paper addresses the pattern of transverse line occurrence and cohort-specific distribution in a plague sample in light of the multiple factors influencing line formation and resorption and discusses the significance of transverse lines as measures of non...

  5. An Alternative Approach to Combination Vaccines: Intradermal Administration of Isolated Components for Control of Anthrax, Botulism, Plague and Staphylococcal Toxic Shock

    Science.gov (United States)

    2008-09-03

    antigens CaF1 and LcrV, previously shown to protect mice against plague [18,19]. The bubonic form of plague results from Yersinia pestis injected into...GP, Adamovicz J, Friedlander AM: Protection against experimental bubonic and pneumonic plague by a recombinant capsular F1-V antigen fusion protein...intradermal administration of isolated components for control of anthrax, botulism, plague and staphylococcal toxic shock Garry L Morefield1, Ralph F

  6. A cluster of primary pneumonic plague transmitted in a truck cab in a new enzootic focus in China.

    Science.gov (United States)

    Luo, Huiming; Dong, Xingqi; Li, Furong; Xie, Xu; Song, Zhizhong; Shao, Zhujun; Li, Zhongjie; Tong, Zhaohui; Wang, Guangfa; Zhang, Hongtao; Yang, Tielong; He, Gao; He, Zeyuan; Fontaine, Robert E; Zeng, Guang

    2013-05-01

    We investigated a cluster of five cases of severe pneumonia from one village in Yunnan Province, China. We searched for severe pneumonia in the village and hospitals. We interviewed patients and family members about exposures. We tested acute and convalescent sera for antigen and antibody of severe acute respiratory syndrome, avian influenza, and plague. The only common exposure of the five patients was riding together in the enclosed cab of a truck for 1.5 hours while taking the first patient to the hospital. Seroconversion to plague F1 antigen confirmed plague in three survivors. Unfamiliarity of clinicians with plague and lack of sputum examination, blood culture, or postmortem examination delayed the diagnosis. No plague cases occurred among family and village contacts and health care workers. High infectivity in this cluster was limited to a crowded, poorly ventilated truck.

  7. 西方小说中的瘟疫题材%Plague Theme in Western Novels

    Institute of Scientific and Technical Information of China (English)

    范蕊; 仵从巨

    2014-01-01

    Plague has an intimate relationship with humans:it not only affects the social process but also has a pro-found impact on people's cultural and spiritual state .The plague is an important theme of literature and many world masterpieces take plague as their background .The plague in the Middle Ages accelerated the Renaissance and the Reformation.Giovanni Boccaccio's Decameron is famous for taking plague as the background .It highlights the value of the Renaissance and the inevitability of Reformation .The 18th-century Enlightenment literature described the world with objective and rational manners .British writer Daniel Defoe's novel A Journal of the Plague Year stressed this tendency .French writer Giono's novel The Horseman on the Roof and the Colombian writer Marquez's Love in the Time of Cholera put plague and love together , the love story dazzling with the plague .In the novel The Plague written by Albert Camus , the plague has a broader symbolism and different choices when people face plague is the expression of existential philosophy .%瘟疫与人类关系密切,不仅影响社会进程还影响人们的文化和精神状态。瘟疫是文学中的重要题材,不少世界名著都以瘟疫为背景,或者直接表现瘟疫。中世纪的瘟疫促进了文艺复兴和宗教改革的出现,意大利作家薄伽丘的《十日谈》就是以瘟疫为背景的名著,突出了文艺复兴时期的价值倾向和宗教改革的必然。18世纪启蒙主义文学以客观理性的态度表现世界,英国作家狄福的《大疫年纪事》则突出表达了这一倾向。法国作家吉奥诺的《屋顶上的骑兵》和哥伦比亚作家马尔克斯的《霍乱时期的爱情》则将瘟疫与爱情同置,爱情故事在瘟疫的映衬下显得光彩夺目。法国存在主义作家加缪的《鼠疫》中,瘟疫具有更广泛的象征意义,面对瘟疫的不同选择突出表达了存在主义的哲学观。

  8. [Risk assessments and control strategies of plague in five key surveillance counties, Zhejiang province].

    Science.gov (United States)

    Shi, Guoxiang; Ju, Cheng; Zhang, Rong; Zhang, Zheng; Sun, Jimin; Wang, Miaoruo; Zhang, Xiaohe; Ye, Xianming; Zhu, Zhihong; Xing, Jianguang; Liao, Xiaowei; Chen, Zhiping

    2015-10-01

    To analyze the epidemiology data on plague in five counties in Zhejiang province and to evaluate the risk of plague in theses areas. We selected five monitoring stations as a risk assessment (Qingyuan county, Longquan city, Yiwu city, Wencheng county, and Ruian city) in Zhejiang province where the plague epidemic more serious in the history. At least one constant site and 1-4 variable sites where plague occurred in history were selected for monitoring. We collected the five counties (cities) surveillance data of indoor rat density, indoor Rattus flavipectus density, the Xenopsylla cheopis index of rat, the Xenopsylla cheopis index of Rattus flavipectus in 1995-2014. Isolation of Yersinia pestis was conducted among 171,201 liver samples and F1 antibody were detected among 228,775 serum samples. Risk matrix, Borda count method, and Delphi approach were conducted to assess risk of the plague of five counties (cities) in Zhejiang province. Indoor rat density in Qingyuan county, Longquan city, Yiwu city, Wencheng county, Ruian city was 1.58%-5.50%, 1.13%-9.76%, 0.56%-3.67%, 2.83%-16.08%, 7.16%-15.96%, respectively; Indoor Rattus flavipectus density of five counties (cities) was 0.08%-2.23%, 0-2.02%, 0-0.54%, 0.71%-5.58%, 0.55%-4.92%, respectively. The Xenopsylla cheopis index of rat in Qingyuan county and Wencheng county was 0.011-0.500 and 0.015-0.227, respectively; The Xenopsylla cheopis index of Rattus flavipectus of Qingyuan county and Wencheng county was 0.119-3.412 and 0.100-1.430, respectively; Ruian City and Yiwu city cannot collected Xenopsylla cheopis, Long quan city only collected the Xenopsylla cheopis index of rat in the five years. Yersinia pestis were not isolated in five counties (cities).There were 3 Apodemus agrarius samples positive of plague F1 antibody test, in Longquan city and Yiwu city in 2005. Borda count method to assess the Longquan city, Yiwu (Borda point were both 321) plague risk was higher than three other regions; Delphi approach to

  9. Contrasted patterns of selection on MHC-linked microsatellites in natural populations of the Malagasy plague reservoir.

    Science.gov (United States)

    Tollenaere, Charlotte; Ivanova, Svilena; Duplantier, Jean-Marc; Loiseau, Anne; Rahalison, Lila; Rahelinirina, Soanandrasana; Brouat, Carine

    2012-01-01

    Plague (Yersinia pestis infection) is a highly virulent rodent disease that persists in many natural ecosystems. The black rat (Rattus rattus) is the main host involved in the plague focus of the central highlands of Madagascar. Black rat populations from this area are highly resistant to plague, whereas those from areas in which the disease is absent (low altitude zones of Madagascar) are susceptible. Various lines of evidence suggest a role for the Major Histocompatibility Complex (MHC) in plague resistance. We therefore used the MHC region as a candidate for detecting signatures of plague-mediated selection in Malagasy black rats, by comparing population genetic structures for five MHC-linked microsatellites and neutral markers in two sampling designs. We first compared four pairs of populations, each pair including one population from the plague focus and one from the disease-free zone. Plague-mediated selection was expected to result in greater genetic differentiation between the two zones than expected under neutrality and this was observed for one MHC-class I-linked locus (D20Img2). For this marker as well as for four other MHC-linked loci, a geographic pattern of genetic structure was found at local scale within the plague focus. This pattern would be expected if plague selection pressures were spatially variable. Finally, another MHC-class I-linked locus (D20Rat21) showed evidences of balancing selection, but it seems more likely that this selection would be related to unknown pathogens more widely distributed in Madagascar than plague.

  10. Contrasted patterns of selection on MHC-linked microsatellites in natural populations of the Malagasy plague reservoir.

    Directory of Open Access Journals (Sweden)

    Charlotte Tollenaere

    Full Text Available Plague (Yersinia pestis infection is a highly virulent rodent disease that persists in many natural ecosystems. The black rat (Rattus rattus is the main host involved in the plague focus of the central highlands of Madagascar. Black rat populations from this area are highly resistant to plague, whereas those from areas in which the disease is absent (low altitude zones of Madagascar are susceptible. Various lines of evidence suggest a role for the Major Histocompatibility Complex (MHC in plague resistance. We therefore used the MHC region as a candidate for detecting signatures of plague-mediated selection in Malagasy black rats, by comparing population genetic structures for five MHC-linked microsatellites and neutral markers in two sampling designs. We first compared four pairs of populations, each pair including one population from the plague focus and one from the disease-free zone. Plague-mediated selection was expected to result in greater genetic differentiation between the two zones than expected under neutrality and this was observed for one MHC-class I-linked locus (D20Img2. For this marker as well as for four other MHC-linked loci, a geographic pattern of genetic structure was found at local scale within the plague focus. This pattern would be expected if plague selection pressures were spatially variable. Finally, another MHC-class I-linked locus (D20Rat21 showed evidences of balancing selection, but it seems more likely that this selection would be related to unknown pathogens more widely distributed in Madagascar than plague.

  11. Spatial analysis of plague in California: niche modeling predictions of the current distribution and potential response to climate change

    Directory of Open Access Journals (Sweden)

    Tucker James R

    2009-06-01

    Full Text Available Abstract Background Plague, caused by the bacterium Yersinia pestis, is a public and wildlife health concern in California and the western United States. This study explores the spatial characteristics of positive plague samples in California and tests Maxent, a machine-learning method that can be used to develop niche-based models from presence-only data, for mapping the potential distribution of plague foci. Maxent models were constructed using geocoded seroprevalence data from surveillance of California ground squirrels (Spermophilus beecheyi as case points and Worldclim bioclimatic data as predictor variables, and compared and validated using area under the receiver operating curve (AUC statistics. Additionally, model results were compared to locations of positive and negative coyote (Canis latrans samples, in order to determine the correlation between Maxent model predictions and areas of plague risk as determined via wild carnivore surveillance. Results Models of plague activity in California ground squirrels, based on recent climate conditions, accurately identified case locations (AUC of 0.913 to 0.948 and were significantly correlated with coyote samples. The final models were used to identify potential plague risk areas based on an ensemble of six future climate scenarios. These models suggest that by 2050, climate conditions may reduce plague risk in the southern parts of California and increase risk along the northern coast and Sierras. Conclusion Because different modeling approaches can yield substantially different results, care should be taken when interpreting future model predictions. Nonetheless, niche modeling can be a useful tool for exploring and mapping the potential response of plague activity to climate change. The final models in this study were used to identify potential plague risk areas based on an ensemble of six future climate scenarios, which can help public managers decide where to allocate surveillance resources

  12. Spatial analysis of plague in California: niche modeling predictions of the current distribution and potential response to climate change.

    Science.gov (United States)

    Holt, Ashley C; Salkeld, Daniel J; Fritz, Curtis L; Tucker, James R; Gong, Peng

    2009-06-28

    Plague, caused by the bacterium Yersinia pestis, is a public and wildlife health concern in California and the western United States. This study explores the spatial characteristics of positive plague samples in California and tests Maxent, a machine-learning method that can be used to develop niche-based models from presence-only data, for mapping the potential distribution of plague foci. Maxent models were constructed using geocoded seroprevalence data from surveillance of California ground squirrels (Spermophilus beecheyi) as case points and Worldclim bioclimatic data as predictor variables, and compared and validated using area under the receiver operating curve (AUC) statistics. Additionally, model results were compared to locations of positive and negative coyote (Canis latrans) samples, in order to determine the correlation between Maxent model predictions and areas of plague risk as determined via wild carnivore surveillance. Models of plague activity in California ground squirrels, based on recent climate conditions, accurately identified case locations (AUC of 0.913 to 0.948) and were significantly correlated with coyote samples. The final models were used to identify potential plague risk areas based on an ensemble of six future climate scenarios. These models suggest that by 2050, climate conditions may reduce plague risk in the southern parts of California and increase risk along the northern coast and Sierras. Because different modeling approaches can yield substantially different results, care should be taken when interpreting future model predictions. Nonetheless, niche modeling can be a useful tool for exploring and mapping the potential response of plague activity to climate change. The final models in this study were used to identify potential plague risk areas based on an ensemble of six future climate scenarios, which can help public managers decide where to allocate surveillance resources. In addition, Maxent model results were significantly

  13. [Analysis on the results of etiology and serology of plague in Qinghai province from 2001 to 2010].

    Science.gov (United States)

    Yang, Yonghai; Wang, Mei; Zhao, Xiaolong; Zhao, Zhongzhi; Zhang, Aiping; Wei, Rongjie; Wei, Baiqing; Wang, Zuyun

    2014-02-01

    To analyze the results of etiology and serology of plague among human and infected animals in Qinghai province from 2001 to 2010. Thirty-seven cases of human infected with plague, 53 541 different animal samples, 5 685 sets of vector insects flea and 49 039 different animal serum samples were obtained between 2001 and 2010. A total of 7 811 samples of serum from healthy farmers and herdsmen in 14 counties in Qinghai from 2005 to 2007 were collected. Yersinia pestis (Y. pestis) were detected in visceral and secretions from human, infected animals and vector insects, respectively. Plague antigen was detected by reverse indirect hemagglutination assay (RIHA) in those samples. Indirect hemagglutination assay (IHA) was used to test plague FI antibody in serum of human and infected animals. 37 human plague cases were confirmed, 21 strains of plague Y. pestis were isolated from human cases and 14 positive were detected out. 133 of 7 811 samples of human serum were IHA positive, with the positive rate at 1.7%. A total of 146 strains of plague were isolated from infected animals and vector insects, 99 out of which were from infected animals, with a ratio of Marmota himalayan at 72.7% (72/99) and the other 47 were from vector insects, with a ratio of callopsylla solaris at 68.1% (32/47). The number of IHA and PIHA positive were 300 and 10, respectively. A total of 3 animals and 3 insects species were identified as new epidemic hosts for plague. The natural plague focus of Microtus fuscus was discovered and confirmed and coexisted with natural focus of Marmota himalayan in Chengduo county, Yushu prefecture. The epidemic situation of plague is distributed mainly in Haixi, Yushu and Hainan prefectures. From 2001 to 2010, animal infected with plague was detected in successive years and human plague was very common in Qinghai. New infected animals and vector insects species and new epidemic areas were confirmed, hence the trend of plague prevalence for humans and animals is very

  14. New Insights into How Yersinia pestis Adapts to Its Mammalian Host during Bubonic Plague

    Science.gov (United States)

    Pradel, Elizabeth; Lemaître, Nadine; Merchez, Maud; Ricard, Isabelle; Reboul, Angéline; Dewitte, Amélie; Sebbane, Florent

    2014-01-01

    Bubonic plague (a fatal, flea-transmitted disease) remains an international public health concern. Although our understanding of the pathogenesis of bubonic plague has improved significantly over the last few decades, researchers have still not been able to define the complete set of Y. pestis genes needed for disease or to characterize the mechanisms that enable infection. Here, we generated a library of Y. pestis mutants, each lacking one or more of the genes previously identified as being up-regulated in vivo. We then screened the library for attenuated virulence in rodent models of bubonic plague. Importantly, we tested mutants both individually and using a novel, “per-pool” screening method that we have developed. Our data showed that in addition to genes involved in physiological adaption and resistance to the stress generated by the host, several previously uncharacterized genes are required for virulence. One of these genes (ympt1.66c, which encodes a putative helicase) has been acquired by horizontal gene transfer. Deletion of ympt1.66c reduced Y. pestis' ability to spread to the lymph nodes draining the dermal inoculation site – probably because loss of this gene decreased the bacteria's ability to survive inside macrophages. Our results suggest that (i) intracellular survival during the early stage of infection is important for plague and (ii) horizontal gene transfer was crucial in the acquisition of this ability. PMID:24675805

  15. The yersiniabactin transport system is critical for the pathogenesis of bubonic and pneumonic plague.

    Science.gov (United States)

    Fetherston, Jacqueline D; Kirillina, Olga; Bobrov, Alexander G; Paulley, James T; Perry, Robert D

    2010-05-01

    Iron acquisition from the host is an important step in the pathogenic process. While Yersinia pestis has multiple iron transporters, the yersiniabactin (Ybt) siderophore-dependent system plays a major role in iron acquisition in vitro and in vivo. In this study, we determined that the Ybt system is required for the use of iron bound by transferrin and lactoferrin and examined the importance of the Ybt system for virulence in mouse models of bubonic and pneumonic plague. Y. pestis mutants unable to either transport Ybt or synthesize the siderophore were both essentially avirulent via subcutaneous injection (bubonic plague model). Surprisingly, via intranasal instillation (pneumonic plague model), we saw a difference in the virulence of Ybt biosynthetic and transport mutants. Ybt biosynthetic mutants displayed an approximately 24-fold-higher 50% lethal dose (LD(50)) than transport mutants. In contrast, under iron-restricted conditions in vitro, a Ybt transport mutant had a more severe growth defect than the Ybt biosynthetic mutant. Finally, a Delta pgm mutant had a greater loss of virulence than the Ybt biosynthetic mutant, indicating that the 102-kb pgm locus encodes a virulence factor, in addition to Ybt, that plays a role in the pathogenesis of pneumonic plague.

  16. New insights into how Yersinia pestis adapts to its mammalian host during bubonic plague.

    Science.gov (United States)

    Pradel, Elizabeth; Lemaître, Nadine; Merchez, Maud; Ricard, Isabelle; Reboul, Angéline; Dewitte, Amélie; Sebbane, Florent

    2014-03-01

    Bubonic plague (a fatal, flea-transmitted disease) remains an international public health concern. Although our understanding of the pathogenesis of bubonic plague has improved significantly over the last few decades, researchers have still not been able to define the complete set of Y. pestis genes needed for disease or to characterize the mechanisms that enable infection. Here, we generated a library of Y. pestis mutants, each lacking one or more of the genes previously identified as being up-regulated in vivo. We then screened the library for attenuated virulence in rodent models of bubonic plague. Importantly, we tested mutants both individually and using a novel, "per-pool" screening method that we have developed. Our data showed that in addition to genes involved in physiological adaptation and resistance to the stress generated by the host, several previously uncharacterized genes are required for virulence. One of these genes (ympt1.66c, which encodes a putative helicase) has been acquired by horizontal gene transfer. Deletion of ympt1.66c reduced Y. pestis' ability to spread to the lymph nodes draining the dermal inoculation site--probably because loss of this gene decreased the bacteria's ability to survive inside macrophages. Our results suggest that (i) intracellular survival during the early stage of infection is important for plague and (ii) horizontal gene transfer was crucial in the acquisition of this ability.

  17. Gr1(+) Cells Control Growth of YopM-Negative Yersinia pestis during Systemic Plague

    NARCIS (Netherlands)

    Ye, Z.; Kerschen, E.J.; Cohen, D.; Kaplan, A.M.; Rooijen, van N.; Straley, S.C.

    2009-01-01

    YopM, a protein toxin of Yersinia pestis, is necessary for virulence in a mouse model of systemic plague. We previously reported YopM-dependent natural killer (NK) cell depletion from blood and spleen samples of infected mice. However, in this study we found that infection with Y. pestis KIM5

  18. Efficacy of ciprofloxacin-gentamicin combination therapy in murine bubonic plague

    National Research Council Canada - National Science Library

    Lemaître, Nadine; Ricard, Isabelle; Pradel, Elizabeth; Foligné, Benoît; Courcol, René; Simonet, Michel; Sebbane, Florent

    2012-01-01

    ... (i) against Yersinia pestis in vitro and (ii) in a mouse model of bubonic plague in which animals were intravenously injected with antibiotics for five days, starting at two different times after infection (44 h and 56 h). In vitro, the CIN...

  19. The Thermoprecipitin Method in the Diagnosis of Bubonic Plague in Cadavers

    OpenAIRE

    Warner, Charlotte E.

    2017-01-01

    The diagnosis of bubonic plague in rat cadavers, the examination of which is a recognised method of prophylaxis for ships or other communities, which may have been in contact with endemic centres, is attended by especial difficulties, and, on the other hand, calls for especial speed and finality in technique

  20. Lessons from the History of Quarantine, from Plague to Influenza A

    Centers for Disease Control (CDC) Podcasts

    2013-05-08

    Reginald Tucker reads an abridged version of the Emerging Infectious Diseases’ Historical Review, Lessons from the History of Quarantine, from Plague to Influenza A.  Created: 5/8/2013 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 5/15/2013.

  1. Quinto Tiberio Angelerio and New Measures for Controlling Plague in 16th-Centruy Alghero, Sardinia

    Centers for Disease Control (CDC) Podcasts

    2013-10-28

    Reginald Tucker reads an abridged version of the Emerging Infectious Diseases’ historical Review, Quinto Tiberio Angelerio and New Measures for Controlling Plague in 16th -Centruy Alghero, Sardinia.  Created: 10/28/2013 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 10/30/2013.

  2. Protecting Black-Footed Ferrets and Prairie Dogs Against Sylvatic Plague

    Science.gov (United States)

    Rocke, Tonie E.

    2008-01-01

    Scientists at the USGS National Wildlife Health Center (NWHC), in collaboration with colleagues at other federal agencies and the University of Wisconsin, are developing and testing vaccines that can be used to protect black-footed ferrets and prairie dogs against plague. The black-footed ferret is commonly regarded as the most endangered mammal in North America, and sylvatic plague is a major impediment to its recovery. The three prairie dog species (Gunnison's, black-tailed, and white-tailed prairie dogs), upon which the ferret depends for food and whose burrows they use for shelter, have been drastically reduced from historical levels, resulting in the near extinction of the ferret. All three species are considered 'at risk' and have been petitioned for listing as 'threatened' or 'endangered' by the U.S. Fish and Wildlife Service (FWS). Additionally, the Utah prairie dog is listed as threatened and the Mexican prairie dog is considered endangered in Mexico. Like the black-footed ferret, all five prairie dog species are highly susceptible to plague and regularly experience outbreaks with devastating losses. Controlling plague outbreaks in prairie dogs and ferrets is a vital concern for ongoing recovery programs and conservation efforts for both species.

  3. [Antoine Deidier, his experimental approach to the contagious nature of plague in Marseille in 1720].

    Science.gov (United States)

    Dutour, Olivier

    2011-01-01

    Born in 1670 Deidier became a medical doctor at the age of 21. The son-in-law, of Vieussens, he took care of the inhabitants of Marseilles during the plague of 1720. A contagionist and an experimenter, he was considered as a strange scientist by his colleagues. It is time now to rehabilitate his memory.

  4. Monitoring the plague of oriental migratory locust using multi-temporal Landsat TM imagery

    Science.gov (United States)

    Liu, Zhenbo; Ni, Shaoxiang; Zha, Yong; Shi, Xuezheng

    2006-03-01

    Locust plague is a kind of the world-wide biological calamity to agriculture. In China's history, more than 90% of locust plagues were caused by the oriental migratory locust, Locusta migratoria manilensis (Meyen). At the present time, it is difficult for monitoring and forecasting systems in this country to provide real time information of locust plague outbreak in large area. In order to adopt timely measures for prevention and control of locust outbreak, it is necessary to apply advanced remote sensing technology for monitoring and forecasting locust outbreak This paper introduces a case study on monitoring oriental migratory locust plague with remote sensing technology in 3 pilot sites, namely, Huangzao, Yangguangzhuang, and Tengnan, which were the 3 major locust damaged areas in Huanghua City, Hebei Province, China during the period of large scale oriental migratory locust breakout in 2002. In this study, locust damage intensity, areas with various damage intensities and their distribution in pilot sites are determined by means of comparison between Landsat ETM+ image of locust damaged vegetation on 31st May, 2002 and TM image of healthy vegetation before damage on 23rd May, 2002. Then, information of various locust distribution density in pilot sites is extracted by establishing the Locust Density Index (LDI).

  5. The Vague Plague -The continual innovation and spread of BPR and IT in Enterprise Networks

    DEFF Research Database (Denmark)

    Koch, Christian

    1998-01-01

    The empirical point of departure of this article is the erosion of enterprise boundaries, which create new conditions for enterprise actors, i.e. they are to an increasing extent forced to operate in networks. They are confronted with a number of unstable and developing change drivers. The focus ...... as a "plague" like SAP R/3, are actually reshaped by the enterprises....

  6. Protecting Black-Footed Ferrets and Prairie Dogs Against Sylvatic Plague

    Science.gov (United States)

    Rocke, Tonie E.

    2008-01-01

    Scientists at the USGS National Wildlife Health Center (NWHC), in collaboration with colleagues at other federal agencies and the University of Wisconsin, are developing and testing vaccines that can be used to protect black-footed ferrets and prairie dogs against plague. The black-footed ferret is commonly regarded as the most endangered mammal in North America, and sylvatic plague is a major impediment to its recovery. The three prairie dog species (Gunnison's, black-tailed, and white-tailed prairie dogs), upon which the ferret depends for food and whose burrows they use for shelter, have been drastically reduced from historical levels, resulting in the near extinction of the ferret. All three species are considered 'at risk' and have been petitioned for listing as 'threatened' or 'endangered' by the U.S. Fish and Wildlife Service (FWS). Additionally, the Utah prairie dog is listed as threatened and the Mexican prairie dog is considered endangered in Mexico. Like the black-footed ferret, all five prairie dog species are highly susceptible to plague and regularly experience outbreaks with devastating losses. Controlling plague outbreaks in prairie dogs and ferrets is a vital concern for ongoing recovery programs and conservation efforts for both species.

  7. Ovid’s Aeginetan plague and the metamorphosis of the Georgics

    NARCIS (Netherlands)

    Heerink, M.A.J.

    2011-01-01

    The influence of the ancient literary tradition upon the Georgics is as broad as it is profound , but in Virgil’s highly allusive didactic poem, the description of the Noric cattle plague at the end of Georgics 3 holds a unique position. As R.F. THOMAS comments, "nowhere else does Virgil draw so

  8. Enhanced Macrophage M1 Polarization and Resistance to Apoptosis Enable Resistance to Plague.

    Science.gov (United States)

    Pachulec, Emilia; Abdelwahed Bagga, Rym Ben; Chevallier, Lucie; O'Donnell, Hope; Guillas, Chloé; Jaubert, Jean; Montagutelli, Xavier; Carniel, Elisabeth; Demeure, Christian E

    2017-09-15

    Susceptibility to infection is in part genetically driven, and C57BL/6 mice resist various pathogens through the proinflammatory response of their M1 macrophages (MPs). However, they are susceptible to plague. It has been reported elsewhere that Mus spretus SEG mice resist plague and develop an immune response characterized by a strong recruitment of MPs. The responses of C57BL/6 and SEG MPs exposed to Yersinia pestis in vitro were examined. SEG MPs exhibit a stronger bactericidal activity with higher nitric oxide production, a more proinflammatory polarized cytokine response, and a higher resistance to Y. pestis-induced apoptosis. This response was not specific to Y. pestis and involved a reduced sensitivity to M2 polarization/signal transducer and activator of transcription 6 activation and inhibition of caspase 8. The enhanced M1 profile was inducible in C57BL/6 MPs in vitro, and when transferred to susceptible C57BL/6 mice, these MPs significantly increased survival of bubonic plague. MPs can develop an enhanced functional profile beyond the prototypic M1, characterized by an even more potent proinflammatory response coordinated with resistance to killing. This programming plays a key role in the plague-resistance phenotype and may be similarly significant in other highly lethal infections, suggesting that orienting the MP response may represent a new therapeutic approach.

  9. Remote sensing for landscape epidemiology : spatial analysis of plague hosts in Kazakhstan

    NARCIS (Netherlands)

    Wilschut, L.I.

    2015-01-01

    The spatial distribution of hosts is a crucial aspect for the understanding of infectious disease dynamics. In Kazakhstan, the great gerbil (Rhombomys opimus) is the main host for plague (Yersinia pestis infection) and poses a public health threat, yet their spatial distribution is unknown. Great

  10. Gr1(+) Cells Control Growth of YopM-Negative Yersinia pestis during Systemic Plague

    NARCIS (Netherlands)

    Ye, Z.; Kerschen, E.J.; Cohen, D.; Kaplan, A.M.; Rooijen, van N.; Straley, S.C.

    2009-01-01

    YopM, a protein toxin of Yersinia pestis, is necessary for virulence in a mouse model of systemic plague. We previously reported YopM-dependent natural killer (NK) cell depletion from blood and spleen samples of infected mice. However, in this study we found that infection with Y. pestis KIM5 (YopM(

  11. Pandemic Fear and Literature: Observations from Jack London’s The Scarlet Plague

    Centers for Disease Control (CDC) Podcasts

    2014-11-18

    Sarah Gregory reads an abridged version of the essay, Pandemic Fear and Literature: Observations from Jack London’s The Scarlet Plague.  Created: 11/18/2014 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 11/20/2014.

  12. Ovid’s Aeginetan plague and the metamorphosis of the Georgics

    NARCIS (Netherlands)

    Heerink, M.A.J.

    2011-01-01

    The influence of the ancient literary tradition upon the Georgics is as broad as it is profound , but in Virgil’s highly allusive didactic poem, the description of the Noric cattle plague at the end of Georgics 3 holds a unique position. As R.F. THOMAS comments, "nowhere else does Virgil draw so dee

  13. REINTRODUCTION OF NOBLE CRAYFISH ASTACUS ASTACUS AFTER CRAYFISH PLAGUE IN NORWAY

    Directory of Open Access Journals (Sweden)

    TAUGBØL T.

    2004-01-01

    Full Text Available The Glomma and Halden watercourses in Norway were hit by crayfish plague in 1987 and 1989. Reintroduction of the noble crayfish started in 1989 in the Glomma and in 1995 in the Halden watercourse. Norway has especially good conditions for reintroduction of the native crayfish after crayfish plague, as there is no alien plague-carrying crayfish species in the country. In the Glomma watercourse, approx. 15 000 adult crayfish and 10 000 juveniles have been stocked while in the Halden watercourse the figures are 19 000 adults and 26 500 juveniles. All stocking sites were previously regarded as very good crayfish localities. Four years after stocking, natural recruitment was recorded at all adult crayfish stocking sites in the Glomma watercourse and at most sites in the Halden watercourse. Current crayfish density is, however, much lower than pre-plague densities even at the sites where population development has been in progress for more than 10 years. Extensive post-stocking movements were recorded among adult crayfish. Some sites seemed more suitable for settling, resulting in a great variation in CPUE between the different test-fishing sites. Juveniles seem more appropriate as stocking material if the goal is to re-establish a population in a particular area, due to their stationary behaviour, which seems to remain as they grow larger.

  14. The Vague Plague -The continual innovation and spread of BPR and IT in Enterprise Networks

    DEFF Research Database (Denmark)

    Koch, Christian

    1998-01-01

    The empirical point of departure of this article is the erosion of enterprise boundaries, which create new conditions for enterprise actors, i.e. they are to an increasing extent forced to operate in networks. They are confronted with a number of unstable and developing change drivers. The focus ...... as a "plague" like SAP R/3, are actually reshaped by the enterprises....

  15. Remote sensing for landscape epidemiology : spatial analysis of plague hosts in Kazakhstan

    NARCIS (Netherlands)

    Wilschut, L.I.

    2015-01-01

    The spatial distribution of hosts is a crucial aspect for the understanding of infectious disease dynamics. In Kazakhstan, the great gerbil (Rhombomys opimus) is the main host for plague (Yersinia pestis infection) and poses a public health threat, yet their spatial distribution is unknown. Great ge

  16. Evaluation of systemic insecticides mixed in rodenticide baits for plague vector control

    DEFF Research Database (Denmark)

    Larsen, Kim Søholt; Lodal, Jens

    1997-01-01

    Rodenticide baits containing systemic insecticides were evaluated in the laboratory for their palatability to the house rat Rattus rattus and for their toxicity against the oriental rat flea Xenopsylla cheopis - both animals are important Vectors of plague in Africa. The test bait and a non...

  17. New insights into how Yersinia pestis adapts to its mammalian host during bubonic plague.

    Directory of Open Access Journals (Sweden)

    Elizabeth Pradel

    2014-03-01

    Full Text Available Bubonic plague (a fatal, flea-transmitted disease remains an international public health concern. Although our understanding of the pathogenesis of bubonic plague has improved significantly over the last few decades, researchers have still not been able to define the complete set of Y. pestis genes needed for disease or to characterize the mechanisms that enable infection. Here, we generated a library of Y. pestis mutants, each lacking one or more of the genes previously identified as being up-regulated in vivo. We then screened the library for attenuated virulence in rodent models of bubonic plague. Importantly, we tested mutants both individually and using a novel, "per-pool" screening method that we have developed. Our data showed that in addition to genes involved in physiological adaptation and resistance to the stress generated by the host, several previously uncharacterized genes are required for virulence. One of these genes (ympt1.66c, which encodes a putative helicase has been acquired by horizontal gene transfer. Deletion of ympt1.66c reduced Y. pestis' ability to spread to the lymph nodes draining the dermal inoculation site--probably because loss of this gene decreased the bacteria's ability to survive inside macrophages. Our results suggest that (i intracellular survival during the early stage of infection is important for plague and (ii horizontal gene transfer was crucial in the acquisition of this ability.

  18. Gr1(+) Cells Control Growth of YopM-Negative Yersinia pestis during Systemic Plague

    NARCIS (Netherlands)

    Ye, Z.; Kerschen, E.J.; Cohen, D.; Kaplan, A.M.; Rooijen, van N.; Straley, S.C.

    2009-01-01

    YopM, a protein toxin of Yersinia pestis, is necessary for virulence in a mouse model of systemic plague. We previously reported YopM-dependent natural killer (NK) cell depletion from blood and spleen samples of infected mice. However, in this study we found that infection with Y. pestis KIM5 (YopM(

  19. The Second Plague Pandemic in the Golden Horde and Its Consequences

    Directory of Open Access Journals (Sweden)

    T.F. Khaydarov

    2014-12-01

    Full Text Available The article reviews the reasons for origin and consequences of spreading for the second plague pandemic in the Golden Horde. By applying scientific data from biology, climatology, medicine, and history, authors come to a conclusion that a large number of natural plague pestholes existed initially in the Ulus of Jochi. Numerous historical sources mentioned plague outbreaks but all of them were of purely local character. The bubonic type of plague characterized by a longer period of illness and an insignificant number of lethal episodes was spread more widely. In the mid-40s of the 14th century a new form of disease, the lung plague, came into existence. It was corpse blackening of the deceased from this type of plague that gave name to the whole pandemic – the “Black Death”. The speed of its progress and spreading significantly exceeded those of the bubonic type and 100% of mortality was recorded among the diseased. However, as historical data show, the outbreak of the lung plague continued in the territory of the Golden Horde from 1346 to 1349. In their article authors prove that one of the most important reasons for the emergence of the lung type was the change in migration flows of Eurasian rodents caused by depletion of nutritional resources in the steppe and serious climatic changes. All other outbreaks of the Black Death are viewed as continuation of the first wave of the disease and their emergence is explained through activity of two natural pestholes (the Relict North-Western and the Lower Volga ones. Consequences of the the first wave were much less substantial for the Ulus of Jochi than those of the following outbreaks (in 1364, 1374, and 1395. The main consequences of the next waves of the disease were: final establishment of 4 political centers (Grand Duchy of Moscow, the Bulgar and the Crimean uluses, and the Blue Horde striving for political leadership in the territory of the former Golden Horde; establishment of a new ethnic

  20. Immune responses to plague infection in wild Rattus rattus, in Madagascar: a role in foci persistence?

    Directory of Open Access Journals (Sweden)

    Voahangy Andrianaivoarimanana

    Full Text Available BACKGROUND: Plague is endemic within the central highlands of Madagascar, where its main reservoir is the black rat, Rattus rattus. Typically this species is considered susceptible to plague, rapidly dying after infection inducing the spread of infected fleas and, therefore, dissemination of the disease to humans. However, persistence of transmission foci in the same area from year to year, supposes mechanisms of maintenance among which rat immune responses could play a major role. Immunity against plague and subsequent rat survival could play an important role in the stabilization of the foci. In this study, we aimed to investigate serological responses to plague in wild black rats from endemic areas of Madagascar. In addition, we evaluate the use of a recently developed rapid serological diagnostic test to investigate the immune response of potential reservoir hosts in plague foci. METHODOLOGY/PRINCIPAL FINDINGS: We experimentally infected wild rats with Yersinia pestis to investigate short and long-term antibody responses. Anti-F1 IgM and IgG were detected to evaluate this antibody response. High levels of anti-F1 IgM and IgG were found in rats one and three weeks respectively after challenge, with responses greatly differing between villages. Plateau in anti-F1 IgM and IgG responses were reached for as few as 500 and 1500 colony forming units (cfu inoculated respectively. More than 10% of rats were able to maintain anti-F1 responses for more than one year. This anti-F1 response was conveniently followed using dipsticks. CONCLUSION/SIGNIFICANCE: Inoculation of very few bacteria is sufficient to induce high immune response in wild rats, allowing their survival after infection. A great heterogeneity of rat immune responses was found within and between villages which could heavily impact on plague epidemiology. In addition, results indicate that, in the field, anti-F1 dipsticks are efficient to investigate plague outbreaks several months after

  1. Spatiotemporal dynamics of black-tailed prairie dog colonies affected by plague

    Science.gov (United States)

    Augustine, D.J.; Matchett, M.R.; Toombs, T.P.; Cully, J.F.; Johnson, T.L.; Sidle, John G.

    2008-01-01

    Black-tailed prairie dogs (Cynomys ludovicianus) are a key component of the disturbance regime in semi-arid grasslands of central North America. Many studies have compared community and ecosystem characteristics on prairie dog colonies to grasslands without prairie dogs, but little is known about landscape-scale patterns of disturbance that prairie dog colony complexes may impose on grasslands over long time periods. We examined spatiotemporal dynamics in two prairie dog colony complexes in southeastern Colorado (Comanche) and northcentral Montana (Phillips County) that have been strongly influenced by plague, and compared them to a complex unaffected by plague in northwestern Nebraska (Oglala). Both plague-affected complexes exhibited substantial spatiotemporal variability in the area occupied during a decade, in contrast to the stability of colonies in the Oglala complex. However, the plague-affected complexes differed in spatial patterns of colony movement. Colonies in the Comanche complex in shortgrass steppe shifted locations over a decade. Only 10% of the area occupied in 1995 was still occupied by prairie dogs in 2006. In 2005 and 2006 respectively, 74 and 83% of the total area of the Comanche complex occurred in locations that were not occupied in 1995, and only 1% of the complex was occupied continuously over a decade. In contrast, prairie dogs in the Phillips County complex in mixed-grass prairie and sagebrush steppe primarily recolonized previously occupied areas after plague-induced colony declines. In Phillips County, 62% of the area occupied in 1993 was also occupied by prairie dogs in 2004, and 12% of the complex was occupied continuously over a decade. Our results indicate that plague accelerates spatiotemporal movement of prairie dog colonies, and have significant implications for landscape-scale effects of prairie dog disturbance on grassland composition and productivity. These findings highlight the need to combine landscape-scale measures of

  2. Enzootic plague reduces black-footed ferret (Mustela nigripes) survival in Montana

    Science.gov (United States)

    Matchett, Marc R.; Biggins, Dean E.; Carlson, Valerie; Powell, Bradford; Rocke, Tonie E.

    2010-01-01

    Black-footed ferrets (Mustela nigripes) require extensive prairie dog colonies (Cynomys spp.) to provide habitat and prey. Epizootic plague kills both prairie dogs and ferrets and is a major factor limiting recovery of the highly endangered ferret. In addition to epizootics, we hypothesized that enzootic plague, that is, presence of disease-causing Yersinia pestis without any noticeable prairie dog die off, may also affect ferret survival. We reduced risk of plague on portions of two ferret reintroduction areas by conducting flea control for 3 years. Beginning in 2004, about half of the ferrets residing on dusted and nondusted colonies were vaccinated against plague with an experimental vaccine (F1-V fusion protein). We evaluated 6-month reencounter rates (percentage of animals observed at the end of an interval that were known alive at the beginning of the interval), an index to survival, for ferrets in four treatment groups involving all combinations of vaccination and flea control. For captive-reared ferrets (115 individuals observed across 156 time intervals), reencounter rates were higher for vaccinates (0.44) than for nonvaccinates (0.23, p = 0.044) on colonies without flea control, but vaccination had no detectable effect on colonies with flea control (vaccinates = 0.41, nonvaccinates = 0.42, p = 0.754). Flea control resulted in higher reencounter rates for nonvaccinates (p = 0.026), but not for vaccinates (p = 0.508). The enhancement of survival due to vaccination or flea control supports the hypothesis that enzootic plague reduces ferret survival, even when there was no noticeable decline in prairie dog abundance. The collective effects of vaccination and flea control compel a conclusion that fleas are required for maintenance, and probably transmission, of plague at enzootic levels. Other studies have demonstrated similar effects of flea control on several species of prairie dogs and, when combined with this study, suggest

  3. Characterization of systemic and pneumonic murine models of plague infection using a conditionally virulent strain.

    Science.gov (United States)

    Mellado-Sanchez, Gabriela; Ramirez, Karina; Drachenberg, Cinthia B; Diaz-McNair, Jovita; Rodriguez, Ana L; Galen, James E; Nataro, James P; Pasetti, Marcela F

    2013-03-01

    Yersinia pestis causes bubonic and pneumonic plague in humans. The pneumonic infection is the most severe and invariably fatal if untreated. Because of its high virulence, ease of delivery and precedent of use in warfare, Y. pestis is considered as a potential bioterror agent. No licensed plague vaccine is currently available in the US. Laboratory research with virulent strains requires appropriate biocontainment (i.e., Biosafety Level 3 (BSL-3) for procedures that generate aerosol/droplets) and secure facilities that comply with federal select agent regulations. To assist in the identification of promising vaccine candidates during the early phases of development, we characterized mouse models of systemic and pneumonic plague infection using the Y. pestis strain EV76, an attenuated human vaccine strain that can be rendered virulent in mice under in vivo iron supplementation. Mice inoculated intranasally or intravenously with Y. pestis EV76 in the presence of iron developed a systemic and pneumonic plague infection that resulted in disease and lethality. Bacteria replicated and severely compromised the spleen, liver and lungs. Susceptibility was age dependent, with younger mice being more vulnerable to pneumonic infection. We used these models of infection to assess the protective capacity of newly developed Salmonella-based plague vaccines. The protective outcome varied depending on the route and dose of infection. Protection was associated with the induction of specific immunological effectors in systemic/mucosal compartments. The models of infection described could serve as safe and practical tools for identifying promising vaccine candidates that warrant further potency evaluation using fully virulent strains in BSL-3 settings. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. [The Justinian plague (part two). Influence of the epidemic on the rise of the Islamic Empire].

    Science.gov (United States)

    Sabbatani, Sergio; Manfredi, Roberto; Fiorino, Sirio

    2012-09-01

    The Islamic Empire started its tumultuous and rapid expansion from the year 622 A.D. (the year of Mohammed's Egira). This rapid growth coincided with the epidemic spread of the bubonic plague in the Middle East. Although a first epidemic event had been documented in the year 570 A.D. (pre-Islamic phase), in the Arabic peninsula, classically according to M.W. Dols five severe episodes of plague sub-epidemics are considered in the middle-eastern geographic area: the first occurred in 627 and 628 A.D., the fifth in 716 A.D.. Anyway, we may state that at the onset of Islam the geographic region including Egypt, Palestine, Syria, Iraq, and Iran was involved by endemic plague. In their work, on the ground of a literature review, the Authors describe the characteristics of the epidemic phenomenon, and analyze the how the plague affected the interpretation of Prophet's Koran and Hadits. The passive attitude demonstrated by many Muslims during early Islam was not shared by all believers, since others moved towards a more soft approach, which included the behaviour of the so called moving aside , when the contagion was of concern. The epidemic plague significantly contributed to the weakening of the Eastern Roman Empire, and the rapid decline of the Persian Empire, while during the early expansion phases of Islam, it indirectly favoured the nomadic Arab tribes which, moving on desert or semi-desert territories, succeeded in escaping the contagion more easily. Subsequently, when the Arab population became sedentary, after occupying the conquered cities, this initial advantage was significantly reduced.

  5. Exposure of small rodents to plague during epizootics in black-tailed prairie dogs.

    Science.gov (United States)

    Stapp, Paul; Salkeld, Daniel J; Eisen, Rebecca J; Pappert, Ryan; Young, John; Carter, Leon G; Gage, Kenneth L; Tripp, Daniel W; Antolin, Michael F

    2008-07-01

    Plague, caused by the bacterium Yersinia pestis, causes die-offs of colonies of prairie dogs (Cynomys ludovicianus). It has been argued that other small rodents are reservoirs for plague, spreading disease during epizootics and maintaining the pathogen in the absence of prairie dogs; yet there is little empirical support for distinct enzootic and epizootic cycles. Between 2004 and 2006, we collected blood from small rodents captured in colonies in northern Colorado before, during, and for up to 2 yr after prairie dog epizootics. We screened 1,603 blood samples for antibodies to Y. pestis, using passive hemagglutination and inhibition tests, and for a subset of samples we cultured blood for the bacterium itself. Of the four species of rodents that were common in colonies, the northern grasshopper mouse (Onychomys leucogaster) was the only species with consistent evidence of plague infection during epizootics, with 11.1-23.1% of mice seropositive for antibody to Y. pestis during these events. Seropositive grasshopper mice, thirteen-lined ground squirrels (Spermophilus tridecemlineatus), and deer mice (Peromyscus maniculatus) were captured the year following epizootics. The appearance of antibodies to Y. pestis in grasshopper mice coincided with periods of high prairie dog mortality; subsequently, antibody prevalence rates declined, with no seropositive individuals captured 2 yr after epizootics. We did not detect plague in any rodents off of colonies, or on colonies prior to epizootics, and found no evidence of persistent Y. pestis infection in blood cultures. Our results suggest that grasshopper mice could be involved in epizootic spread of Y. pestis, and possibly, serve as a short-term reservoir for plague, but provide no evidence that the grasshopper mouse or any small rodent acts as a long-term, enzootic host for Y. pestis in prairie dog colonies.

  6. Histopathological observation of immunized rhesus macaques with plague vaccines after subcutaneous infection of Yersinia pestis.

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    Guang Tian

    Full Text Available In our previous study, complete protection was observed in Chinese-origin rhesus macaques immunized with SV1 (20 µg F1 and 10 µg rV270 and SV2 (200 µg F1 and 100 µg rV270 subunit vaccines and with EV76 live attenuated vaccine against subcutaneous challenge with 6×10(6 CFU of Y. pestis. In the present study, we investigated whether the vaccines can effectively protect immunized animals from any pathologic changes using histological and immunohistochemical techniques. In addition, the glomerular basement membranes (GBMs of the immunized animals and control animals were checked by electron microscopy. The results show no signs of histopathological lesions in the lungs, livers, kidneys, lymph nodes, spleens and hearts of the immunized animals at Day 14 after the challenge, whereas pathological alterations were seen in the corresponding tissues of the control animals. Giemsa staining, ultrastructural examination, and immunohistochemical staining revealed bacteria in some of the organs of the control animals, whereas no bacterium was observed among the immunized animals. Ultrastructural observation revealed that no glomerular immune deposits on the GBM. These observations suggest that the vaccines can effectively protect animals from any pathologic changes and eliminate Y. pestis from the immunized animals. The control animals died from multi-organ lesions specifically caused by the Y. pestis infection. We also found that subcutaneous infection of animals with Y. pestis results in bubonic plague, followed by pneumonic and septicemic plagues. The histopathologic features of plague in rhesus macaques closely resemble those of rodent and human plagues. Thus, Chinese-origin rhesus macaques serve as useful models in studying Y. pestis pathogenesis, host response and the efficacy of new medical countermeasures against plague.

  7. Yersinia pestis DNA from skeletal remains from the 6(th) century AD reveals insights into Justinianic Plague.

    Science.gov (United States)

    Harbeck, Michaela; Seifert, Lisa; Hänsch, Stephanie; Wagner, David M; Birdsell, Dawn; Parise, Katy L; Wiechmann, Ingrid; Grupe, Gisela; Thomas, Astrid; Keim, Paul; Zöller, Lothar; Bramanti, Barbara; Riehm, Julia M; Scholz, Holger C

    2013-01-01

    Yersinia pestis, the etiologic agent of the disease plague, has been implicated in three historical pandemics. These include the third pandemic of the 19(th) and 20(th) centuries, during which plague was spread around the world, and the second pandemic of the 14(th)-17(th) centuries, which included the infamous epidemic known as the Black Death. Previous studies have confirmed that Y. pestis caused these two more recent pandemics. However, a highly spirited debate still continues as to whether Y. pestis caused the so-called Justinianic Plague of the 6(th)-8(th) centuries AD. By analyzing ancient DNA in two independent ancient DNA laboratories, we confirmed unambiguously the presence of Y. pestis DNA in human skeletal remains from an Early Medieval cemetery. In addition, we narrowed the phylogenetic position of the responsible strain down to major branch 0 on the Y. pestis phylogeny, specifically between nodes N03 and N05. Our findings confirm that Y. pestis was responsible for the Justinianic Plague, which should end the controversy regarding the etiology of this pandemic. The first genotype of a Y. pestis strain that caused the Late Antique plague provides important information about the history of the plague bacillus and suggests that the first pandemic also originated in Asia, similar to the other two plague pandemics.

  8. Yersinia pestis DNA from skeletal remains from the 6(th century AD reveals insights into Justinianic Plague.

    Directory of Open Access Journals (Sweden)

    Michaela Harbeck

    Full Text Available Yersinia pestis, the etiologic agent of the disease plague, has been implicated in three historical pandemics. These include the third pandemic of the 19(th and 20(th centuries, during which plague was spread around the world, and the second pandemic of the 14(th-17(th centuries, which included the infamous epidemic known as the Black Death. Previous studies have confirmed that Y. pestis caused these two more recent pandemics. However, a highly spirited debate still continues as to whether Y. pestis caused the so-called Justinianic Plague of the 6(th-8(th centuries AD. By analyzing ancient DNA in two independent ancient DNA laboratories, we confirmed unambiguously the presence of Y. pestis DNA in human skeletal remains from an Early Medieval cemetery. In addition, we narrowed the phylogenetic position of the responsible strain down to major branch 0 on the Y. pestis phylogeny, specifically between nodes N03 and N05. Our findings confirm that Y. pestis was responsible for the Justinianic Plague, which should end the controversy regarding the etiology of this pandemic. The first genotype of a Y. pestis strain that caused the Late Antique plague provides important information about the history of the plague bacillus and suggests that the first pandemic also originated in Asia, similar to the other two plague pandemics.

  9. Yersinia pestis DNA from Skeletal Remains from the 6th Century AD Reveals Insights into Justinianic Plague

    Science.gov (United States)

    Harbeck, Michaela; Seifert, Lisa; Hänsch, Stephanie; Wagner, David M.; Birdsell, Dawn; Parise, Katy L.; Wiechmann, Ingrid; Grupe, Gisela; Thomas, Astrid; Keim, Paul; Zöller, Lothar; Bramanti, Barbara; Riehm, Julia M.; Scholz, Holger C.

    2013-01-01

    Yersinia pestis, the etiologic agent of the disease plague, has been implicated in three historical pandemics. These include the third pandemic of the 19th and 20th centuries, during which plague was spread around the world, and the second pandemic of the 14th–17th centuries, which included the infamous epidemic known as the Black Death. Previous studies have confirmed that Y. pestis caused these two more recent pandemics. However, a highly spirited debate still continues as to whether Y. pestis caused the so-called Justinianic Plague of the 6th–8th centuries AD. By analyzing ancient DNA in two independent ancient DNA laboratories, we confirmed unambiguously the presence of Y. pestis DNA in human skeletal remains from an Early Medieval cemetery. In addition, we narrowed the phylogenetic position of the responsible strain down to major branch 0 on the Y. pestis phylogeny, specifically between nodes N03 and N05. Our findings confirm that Y. pestis was responsible for the Justinianic Plague, which should end the controversy regarding the etiology of this pandemic. The first genotype of a Y. pestis strain that caused the Late Antique plague provides important information about the history of the plague bacillus and suggests that the first pandemic also originated in Asia, similar to the other two plague pandemics. PMID:23658525

  10. Evaluation of Yersinia pestis transmission pathways for sylvatic plague in prairie dog populations in the western U.S.

    Science.gov (United States)

    Richgels, Katherine L. D.; Russell, Robin E.; Bron, Gebbiena; Rocke, Tonie E.

    2016-01-01

    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.

  11. Evaluation of Yersinia pestis Transmission Pathways for Sylvatic Plague in Prairie Dog Populations in the Western U.S.

    Science.gov (United States)

    Richgels, Katherine L D; Russell, Robin E; Bron, Gebbiena M; Rocke, Tonie E

    2016-06-01

    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.

  12. Landscape and Residential Variables Associated with Plague-Endemic Villages in the West Nile Region of Uganda

    Science.gov (United States)

    MacMillan, Katherine; Enscore, Russell E.; Ogen-Odoi, Asaph; Borchert, Jeff N.; Babi, Nackson; Amatre, Gerald; Atiku, Linda A.; Mead, Paul S.; Gage, Kenneth L.; Eisen, Rebecca J.

    2011-01-01

    Plague, caused by the bacteria Yersinia pestis, is a severe, often fatal disease. This study focuses on the plague-endemic West Nile region of Uganda, where limited information is available regarding environmental and behavioral risk factors associated with plague infection. We conducted observational surveys of 10 randomly selected huts within historically classified case and control villages (four each) two times during the dry season of 2006 (N = 78 case huts and N = 80 control huts), which immediately preceded a large plague outbreak. By coupling a previously published landscape-level statistical model of plague risk with this observational survey, we were able to identify potential residence-based risk factors for plague associated with huts within historic case or control villages (e.g., distance to neighboring homestead and presence of pigs near the home) and huts within areas previously predicted as elevated risk or low risk (e.g., corn and other annual crops grown near the home, water storage in the home, and processed commercial foods stored in the home). The identified variables are consistent with current ecologic theories on plague transmission dynamics. This preliminary study serves as a foundation for future case control studies in the area. PMID:21363983

  13. [IMPACT OF CASPIAN SEA LEVEL FLUCTUATIONS ON THE EPIZOOTIC ACTIVITY OF THE CASPIAN SANDY NATURAL PLAGUE FOCUS].

    Science.gov (United States)

    Popov, N V; Udovikov, A I; Eroshenko, G A; Karavaeva, T B; Yakovlev, S A; Porshakov, A M; Zenkevich, E S; Kutyrev, V V

    2016-01-01

    There is evidence that in 1923-2014 the sharp aggravations of the epizootic situation of plague in the area of its Caspian sandy natural focus after long interepizootic periods are in time with the ups of the Caspian Sea in the extrema of 11-year solar cycles. There were cases of multiple manifestations of plague in the same areas in the epizootic cycles of 1946-1954, 1979-1996, 2001, and 2013-2014. The paper considers the possible role of amebae of the genus Acanthamoeba and nematodes, the representatives of the orders Rhabditida and Tylenchida in the microfocal pattern of plague manifestations.

  14. Recent results on the spatiotemporal modelling and comparative analysis of Black Death and bubonic plague epidemics.

    Science.gov (United States)

    Christakos, G; Olea, R A; Yu, H-L

    2007-09-01

    This work demonstrates the importance of spatiotemporal stochastic modelling in constructing maps of major epidemics from fragmentary information, assessing population impacts, searching for possible etiologies, and performing comparative analysis of epidemics. Based on the theory previously published by the authors and incorporating new knowledge bases, informative maps of the composite space-time distributions were generated for important characteristics of two major epidemics: Black Death (14th century Western Europe) and bubonic plague (19th-20th century Indian subcontinent). The comparative spatiotemporal analysis of the epidemics led to a number of interesting findings: (1) the two epidemics exhibited certain differences in their spatiotemporal characteristics (correlation structures, trends, occurrence patterns and propagation speeds) that need to be explained by means of an interdisciplinary effort; (2) geographical epidemic indicators confirmed in a rigorous quantitative manner the partial findings of isolated reports and time series that Black Death mortality was two orders of magnitude higher than that of bubonic plague; (3) modern bubonic plague is a rural disease hitting harder the small villages in the countryside whereas Black Death was a devastating epidemic that indiscriminately attacked large urban centres and the countryside, and while the epidemic in India lasted uninterruptedly for five decades, in Western Europe it lasted three and a half years; (4) the epidemics had reverse areal extension features in response to annual seasonal variations. Temperature increase at the end of winter led to an expansion of infected geographical area for Black Death and a reduction for bubonic plague, reaching a climax at the end of spring when the infected area in Western Europe was always larger than in India. Conversely, without exception, the infected area during winter was larger for the Indian bubonic plague; (5) during the Indian epidemic, the disease

  15. Recent results on the spatiotemporal modelling and comparative analysis of Black Death and bubonic plague epidemics

    Science.gov (United States)

    Christakos, G.; Olea, R.A.; Yu, H.-L.

    2007-01-01

    Background: This work demonstrates the importance of spatiotemporal stochastic modelling in constructing maps of major epidemics from fragmentary information, assessing population impacts, searching for possible etiologies, and performing comparative analysis of epidemics. Methods: Based on the theory previously published by the authors and incorporating new knowledge bases, informative maps of the composite space-time distributions were generated for important characteristics of two major epidemics: Black Death (14th century Western Europe) and bubonic plague (19th-20th century Indian subcontinent). Results: The comparative spatiotemporal analysis of the epidemics led to a number of interesting findings: (1) the two epidemics exhibited certain differences in their spatiotemporal characteristics (correlation structures, trends, occurrence patterns and propagation speeds) that need to be explained by means of an interdisciplinary effort; (2) geographical epidemic indicators confirmed in a rigorous quantitative manner the partial findings of isolated reports and time series that Black Death mortality was two orders of magnitude higher than that of bubonic plague; (3) modern bubonic plague is a rural disease hitting harder the small villages in the countryside whereas Black Death was a devastating epidemic that indiscriminately attacked large urban centres and the countryside, and while the epidemic in India lasted uninterruptedly for five decades, in Western Europe it lasted three and a half years; (4) the epidemics had reverse areal extension features in response to annual seasonal variations. Temperature increase at the end of winter led to an expansion of infected geographical area for Black Death and a reduction for bubonic plague, reaching a climax at the end of spring when the infected area in Western Europe was always larger than in India. Conversely, without exception, the infected area during winter was larger for the Indian bubonic plague; (5) during the

  16. The analysis of monitoring results of plague and plague in Honghe County%红河县鼠疫概况及鼠疫监测结果分析

    Institute of Scientific and Technical Information of China (English)

    王兵

    2013-01-01

    目的:介绍红河县鼠疫概况,并分析1998年建立鼠疫监测机构后所做的鼠疫监测数据。方法对1998---2012年红河县鼠疫监测资料进行整理、统计、分析。结果红河县属于滇闽家鼠鼠疫疫源地,到目前发现动物疫点23个,人间疫点6个,腺鼠疫病人15例,分布于13个乡(镇)中的4个乡(镇)。检出鼠疫菌27株,IHA阳性血清15份,RIHA阳性42份。结论红河县鼠疫流行期己过,鼠疫可能转入静息期。%Objective Brief introduction of Honghe County plague,plague monitoring data and analysis of the monitoring mechanism established in 1998 after the plague.Method To collate,statistics,analysis of the Honghe County plague monitoring data of 1998---2012.Result Honghe County of Yunnan and Fujian plague fo-cus,to animal epidemic currently found in 23,the world was 6,15 cases of bubonic plague patients,distributed in 13 townships(town)in 4 townships(town).Detection of 27 strains of Yersinia pestis,IHA 15 positive sera,42 samples were positive for RIHA.Conclusion Honghe County plague epidemic period has elapsed,the plague may lead to the resting period.

  17. Effects of weather and plague-induced die-offs of prairie dogs on the fleas of northern grasshopper mice.

    Science.gov (United States)

    Salkeld, Daniel J; Stapp, Paul

    2009-05-01

    Plague, the disease caused by the bacterium Yersinia pestis, can have devastating impacts on black-tailed prairie dogs (Cynomys ludovicianus Ord). Other mammal hosts living on prairie dog colonies may be important in the transmission and maintenance of plague. We examined the flea populations of northern grasshopper mice (Onychomys leucogaster Wied) before, during, and after plague epizootics in northern Colorado and studied the influence of host and environmental factors on flea abundance patterns. Grasshopper mice were frequently infested with high numbers of fleas, most commonly Pleochaetis exilis Jordan and Thrassis fotus Jordan. Flea loads changed in response to both environmental temperature and rainfall. After plague-induced prairie dog die-offs, flea loads and likelihood of infestation were unchanged for P. exilis, but T. fotus loads declined.

  18. Historical Y. pestis Genomes Reveal the European Black Death as the Source of Ancient and Modern Plague Pandemics.

    Science.gov (United States)

    Spyrou, Maria A; Tukhbatova, Rezeda I; Feldman, Michal; Drath, Joanna; Kacki, Sacha; Beltrán de Heredia, Julia; Arnold, Susanne; Sitdikov, Airat G; Castex, Dominique; Wahl, Joachim; Gazimzyanov, Ilgizar R; Nurgaliev, Danis K; Herbig, Alexander; Bos, Kirsten I; Krause, Johannes

    2016-06-08

    Ancient DNA analysis has revealed an involvement of the bacterial pathogen Yersinia pestis in several historical pandemics, including the second plague pandemic (Europe, mid-14(th) century Black Death until the mid-18(th) century AD). Here we present reconstructed Y. pestis genomes from plague victims of the Black Death and two subsequent historical outbreaks spanning Europe and its vicinity, namely Barcelona, Spain (1300-1420 cal AD), Bolgar City, Russia (1362-1400 AD), and Ellwangen, Germany (1485-1627 cal AD). Our results provide support for (1) a single entry of Y. pestis in Europe during the Black Death, (2) a wave of plague that traveled toward Asia to later become the source population for contemporary worldwide epidemics, and (3) the presence of an historical European plague focus involved in post-Black Death outbreaks that is now likely extinct. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Plague studies in California: a review of long-term disease activity, flea-host relationships and plague ecology in the coniferous forests of the Southern Cascades and northern Sierra Nevada mountains.

    Science.gov (United States)

    Smith, Charles R; Tucker, James R; Wilson, Barbara A; Clover, James R

    2010-06-01

    We review 28 years of long-term surveillance (1970-1997) for plague activity among wild rodents from ten locations within three coniferous forest habitat types in the northern Sierra Nevada and the Southern Cascade mountains of northeastern California. We identify rodent hosts and their fleas and document long-term plague activity in each habitat type. The highest seroprevalence for Yersinia pestis occurred in the chipmunks, Tamias senex and T. quadrimaculatus, and the pine squirrel, Tamiasciurus douglasii. The most commonly infected fleas were Ceratophyllus ciliatus and Eumolpianus eumolpi from chipmunks and Oropsylla montana and O. idahoensis from ground squirrels. Serological surveillance demonstrated that populations of T. senex, T. quadrimaculatus and T. douglasii are moderately resistant to plague, survive infection, and are, therefore, good sentinels for plague activity. Recaptured T. senex and T. quadrimaculatus showed persistence of plague antibodies and evidence of re-infection over a two year period. These rodent species, their fleas, and the ecological factors common to the coniferous forest habitats likely promote the maintenance of plague foci in northeastern California.

  20. Advances on study of plague indicator animals in the plague nature foci in China%鼠疫自然疫源地鼠疫指示动物研究进展

    Institute of Scientific and Technical Information of China (English)

    王治宇; 张志霞; 刘海翔; 杨建明; 王海峰; 杨顺林; 史献明; 杜国义

    2016-01-01

    鼠疫是一种以啮齿类动物为主要宿主的自然疫源性疾病。目前发现可自然感染鼠疫耶尔森菌(鼠疫菌)的动物有223种。鼠疫指示动物是指在自然界中可自然感染鼠疫菌,对其具有低敏感性、高抗性的动物,该类动物在鼠疫菌的保存和传播中有重要作用。通过对高抗动物的调查和研究,为早期发现和追踪疫情提供科学依据。%Plague is an enzootic infectious disease. The rodent animals are primary reservoir hosts of plague. There are 223 kinds of animal which have been found to be infected with plague in nature. Plague⁃tolerant animals which can be naturally infected with plague without symptoms serve as plague⁃indicators. These animals also play a very important role in the spread of the plague. The research of plague⁃indicating animals was reviewed in this paper which provides scientific basis for plague prevention and control in China.

  1. Primary case of human pneumonic plague occurring in a Himalayan marmot natural focus area Gansu Province, China

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    Pengfei Ge

    2015-04-01

    Full Text Available A case of primary pneumonic plague (PPP caused by Yersinia pestis is reported. This case occurred in the largest plague area in China. The patient died after contact with a dog that had captured an infected marmot. Three of 151 contacts were shown to be positive for antibody against F1 antigen by indirect hemagglutination assay, but none had clinical symptoms. There was no secondary case.

  2. Primary case of human pneumonic plague occurring in a Himalayan marmot natural focus area Gansu Province, China.

    Science.gov (United States)

    Ge, Pengfei; Xi, Jinxiao; Ding, Jun; Jin, Fachang; Zhang, Hong; Guo, Limin; Zhang, Jie; Li, Junlin; Gan, Zhiqiang; Wu, Bin; Liang, Junrong; Wang, Xin; Wang, Xinhua

    2015-04-01

    A case of primary pneumonic plague (PPP) caused by Yersinia pestis is reported. This case occurred in the largest plague area in China. The patient died after contact with a dog that had captured an infected marmot. Three of 151 contacts were shown to be positive for antibody against F1 antigen by indirect hemagglutination assay, but none had clinical symptoms. There was no secondary case.

  3. yadBC of Yersinia pestis, a new virulence determinant for bubonic plague.

    Science.gov (United States)

    Forman, Stanislav; Wulff, Christine R; Myers-Morales, Tanya; Cowan, Clarissa; Perry, Robert D; Straley, Susan C

    2008-02-01

    In all Yersinia pestis strains examined, the adhesin/invasin yadA gene is a pseudogene, yet Y. pestis is invasive for epithelial cells. To identify potential surface proteins that are structurally and functionally similar to YadA, we searched the Y. pestis genome for open reading frames with homology to yadA and found three: the bicistronic operon yadBC (YPO1387 and YPO1388 of Y. pestis CO92; y2786 and y2785 of Y. pestis KIM5), which encodes two putative surface proteins, and YPO0902, which lacks a signal sequence and likely is nonfunctional. In this study we characterized yadBC regulation and tested the importance of this operon for Y. pestis adherence, invasion, and virulence. We found that loss of yadBC caused a modest loss of invasiveness for epithelioid cells and a large decrease in virulence for bubonic plague but not for pneumonic plague in mice.

  4. A survey of North American migratory waterfowl for duck plague (duck virus enteritis) virus

    Science.gov (United States)

    Brand, Christopher J.; Docherty, Douglas E.

    1984-01-01

    A survey of migratory waterfowl for duck plague (DP) virus was conducted in the Mississippi and Central flyways during 1982 and in the Atlantic and Pacific flyways during 1983. Cloacal and pharyngeal swabs were collected from 3,169 migratory waterfowl in these four flyways, principally mallards (Anas platyrhynchos L.), black ducks (Anas rubripes Brewster), and pintails (Anas acuta L). In addition 1,033 birds were sampled from areas of recurrent DP outbreaks among nonmigratory and captive waterfowl, and 590 from Lake Andes National Wildlife Refuge, the site of the only known major DP outbreak in migratory waterfowl. Duck plague virus was not found in any of the samples. Results support the hypothesis that DP is not established in North American migratory waterfowl as an enzootic disease.

  5. The effects of plague on the distribution of property: Ivrea, Northern Italy 1630.

    Science.gov (United States)

    Alfani, Guido

    2010-03-01

    The demographic effects of the epidemics of plague in Early Modern Europe and their economic consequences illuminate the evolution of property structures and of wealth distribution during and after a mortality crisis. An analysis of the high-quality data available for the Italian city of Ivrea at the time of the 1630 plague shows the exceptional resilience of property structures. Like the social structures of the period, property structures were able to recover quickly, informed as they were by the lessons learnt by trial and error by the patrician families of the late Middle Ages, whose patrimonies had been badly damaged by the Black Death. In a period of recurrent catastrophes that struck European populations during the Old Demographic Regime, apparently 'inegalitarian' institutions seem to have had long-term 'egalitarian' effects.

  6. High throughput, multiplexed pathogen detection authenticates plague waves in medieval Venice, Italy.

    Science.gov (United States)

    Tran, Thi-Nguyen-Ny; Signoli, Michel; Fozzati, Luigi; Aboudharam, Gérard; Raoult, Didier; Drancourt, Michel

    2011-03-10

    Historical records suggest that multiple burial sites from the 14th-16th centuries in Venice, Italy, were used during the Black Death and subsequent plague epidemics. High throughput, multiplexed real-time PCR detected DNA of seven highly transmissible pathogens in 173 dental pulp specimens collected from 46 graves. Bartonella quintana DNA was identified in five (2.9%) samples, including three from the 16th century and two from the 15th century, and Yersinia pestis DNA was detected in three (1.7%) samples, including two from the 14th century and one from the 16th century. Partial glpD gene sequencing indicated that the detected Y. pestis was the Orientalis biotype. These data document for the first time successive plague epidemics in the medieval European city where quarantine was first instituted in the 14th century.

  7. High throughput, multiplexed pathogen detection authenticates plague waves in medieval Venice, Italy.

    Directory of Open Access Journals (Sweden)

    Thi-Nguyen-Ny Tran

    Full Text Available BACKGROUND: Historical records suggest that multiple burial sites from the 14th-16th centuries in Venice, Italy, were used during the Black Death and subsequent plague epidemics. METHODOLOGY/PRINCIPAL FINDINGS: High throughput, multiplexed real-time PCR detected DNA of seven highly transmissible pathogens in 173 dental pulp specimens collected from 46 graves. Bartonella quintana DNA was identified in five (2.9% samples, including three from the 16th century and two from the 15th century, and Yersinia pestis DNA was detected in three (1.7% samples, including two from the 14th century and one from the 16th century. Partial glpD gene sequencing indicated that the detected Y. pestis was the Orientalis biotype. CONCLUSIONS: These data document for the first time successive plague epidemics in the medieval European city where quarantine was first instituted in the 14th century.

  8. Exploring the Outside and the Inside: Double Vision in Joan Slonczewski’s Brain Plague

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    Mateusz Marecki

    2012-08-01

    Full Text Available With its vision of how the possibility of enhancing the human brain by means of intelligent microbes would change the nature of humanity, Slonczewski’s Brain Plague (2000 provides a fertile ground for multiple interpretations. Deploying the theme of intelligence and the brain, it belongs to the literature linked to the life sciences. In terms of its generic aspect, the novel should be classified as hard science fiction, because it is predicated on scientific underpinnings. In this paper, however, Brain Plague is, in the first place, viewed as a double parabolic projection serving as a social critique of the actual world and as an educational tool. Employing the notions of parabolic projection and conceptual metaphor, both formulated under the cognitive poetics paradigm, the paper seeks to demonstrate how Slonczewski, a scientist holding a PhD in biology and a popular writer, elicits in the reader the aesthetic effect called cognitive engagement.

  9. Early host cell targets of Yersinia pestis during primary pneumonic plague.

    Directory of Open Access Journals (Sweden)

    Roger D Pechous

    Full Text Available Inhalation of Yersinia pestis causes primary pneumonic plague, a highly lethal syndrome with mortality rates approaching 100%. Pneumonic plague progression is biphasic, with an initial pre-inflammatory phase facilitating bacterial growth in the absence of host inflammation, followed by a pro-inflammatory phase marked by extensive neutrophil influx, an inflammatory cytokine storm, and severe tissue destruction. Using a FRET-based probe to quantitate injection of effector proteins by the Y. pestis type III secretion system, we show that these bacteria target alveolar macrophages early during infection of mice, followed by a switch in host cell preference to neutrophils. We also demonstrate that neutrophil influx is unable to limit bacterial growth in the lung and is ultimately responsible for the severe inflammation during the lethal pro-inflammatory phase.

  10. Host resistance, population structure and the long-term persistence of bubonic plague: contributions of a modelling approach in the Malagasy focus.

    Science.gov (United States)

    Gascuel, Fanny; Choisy, Marc; Duplantier, Jean-Marc; Débarre, Florence; Brouat, Carine

    2013-01-01

    Although bubonic plague is an endemic zoonosis in many countries around the world, the factors responsible for the persistence of this highly virulent disease remain poorly known. Classically, the endemic persistence of plague is suspected to be due to the coexistence of plague resistant and plague susceptible rodents in natural foci, and/or to a metapopulation structure of reservoirs. Here, we test separately the effect of each of these factors on the long-term persistence of plague. We analyse the dynamics and equilibria of a model of plague propagation, consistent with plague ecology in Madagascar, a major focus where this disease is endemic since the 1920s in central highlands. By combining deterministic and stochastic analyses of this model, and including sensitivity analyses, we show that (i) endemicity is favoured by intermediate host population sizes, (ii) in large host populations, the presence of resistant rats is sufficient to explain long-term persistence of plague, and (iii) the metapopulation structure of susceptible host populations alone can also account for plague endemicity, thanks to both subdivision and the subsequent reduction in the size of subpopulations, and extinction-recolonization dynamics of the disease. In the light of these results, we suggest scenarios to explain the localized presence of plague in Madagascar.

  11. Plague circulation and population genetics of the reservoir Rattus rattus: the influence of topographic relief on the distribution of the disease within the Madagascan focus.

    Directory of Open Access Journals (Sweden)

    Carine Brouat

    Full Text Available BACKGROUND: Landscape may affect the distribution of infectious diseases by influencing the population density and dispersal of hosts and vectors. Plague (Yersinia pestis infection is a highly virulent, re-emerging disease, the ecology of which has been scarcely studied in Africa. Human seroprevalence data for the major plague focus of Madagascar suggest that plague spreads heterogeneously across the landscape as a function of the relief. Plague is primarily a disease of rodents. We therefore investigated the relationship between disease distribution and the population genetic structure of the black rat, Rattus rattus, the main reservoir of plague in Madagascar. METHODOLOGY/PRINCIPAL FINDINGS: We conducted a comparative study of plague seroprevalence and genetic structure (15 microsatellite markers in rat populations from four geographic areas differing in topology, each covering about 150-200 km(2 within the Madagascan plague focus. The seroprevalence levels in the rat populations mimicked those previously reported for humans. As expected, rat populations clearly displayed a more marked genetic structure with increasing relief. However, the relationship between seroprevalence data and genetic structure differs between areas, suggesting that plague distribution is not related everywhere to the effective dispersal of rats. CONCLUSIONS/SIGNIFICANCE: Genetic diversity estimates suggested that plague epizootics had only a weak impact on rat population sizes. In the highlands of Madagascar, plague dissemination cannot be accounted for solely by the effective dispersal of the reservoir. Human social activities may also be involved in spreading the disease in rat and human populations.

  12. Plague circulation and population genetics of the reservoir Rattus rattus: the influence of topographic relief on the distribution of the disease within the Madagascan focus.

    Science.gov (United States)

    Brouat, Carine; Rahelinirina, Soanandrasana; Loiseau, Anne; Rahalison, Lila; Rajerison, Minoariso; Laffly, Dominique; Handschumacher, Pascal; Duplantier, Jean-Marc

    2013-01-01

    Landscape may affect the distribution of infectious diseases by influencing the population density and dispersal of hosts and vectors. Plague (Yersinia pestis infection) is a highly virulent, re-emerging disease, the ecology of which has been scarcely studied in Africa. Human seroprevalence data for the major plague focus of Madagascar suggest that plague spreads heterogeneously across the landscape as a function of the relief. Plague is primarily a disease of rodents. We therefore investigated the relationship between disease distribution and the population genetic structure of the black rat, Rattus rattus, the main reservoir of plague in Madagascar. We conducted a comparative study of plague seroprevalence and genetic structure (15 microsatellite markers) in rat populations from four geographic areas differing in topology, each covering about 150-200 km(2) within the Madagascan plague focus. The seroprevalence levels in the rat populations mimicked those previously reported for humans. As expected, rat populations clearly displayed a more marked genetic structure with increasing relief. However, the relationship between seroprevalence data and genetic structure differs between areas, suggesting that plague distribution is not related everywhere to the effective dispersal of rats. Genetic diversity estimates suggested that plague epizootics had only a weak impact on rat population sizes. In the highlands of Madagascar, plague dissemination cannot be accounted for solely by the effective dispersal of the reservoir. Human social activities may also be involved in spreading the disease in rat and human populations.

  13. Host resistance, population structure and the long-term persistence of bubonic plague: contributions of a modelling approach in the Malagasy focus.

    Directory of Open Access Journals (Sweden)

    Fanny Gascuel

    Full Text Available Although bubonic plague is an endemic zoonosis in many countries around the world, the factors responsible for the persistence of this highly virulent disease remain poorly known. Classically, the endemic persistence of plague is suspected to be due to the coexistence of plague resistant and plague susceptible rodents in natural foci, and/or to a metapopulation structure of reservoirs. Here, we test separately the effect of each of these factors on the long-term persistence of plague. We analyse the dynamics and equilibria of a model of plague propagation, consistent with plague ecology in Madagascar, a major focus where this disease is endemic since the 1920s in central highlands. By combining deterministic and stochastic analyses of this model, and including sensitivity analyses, we show that (i endemicity is favoured by intermediate host population sizes, (ii in large host populations, the presence of resistant rats is sufficient to explain long-term persistence of plague, and (iii the metapopulation structure of susceptible host populations alone can also account for plague endemicity, thanks to both subdivision and the subsequent reduction in the size of subpopulations, and extinction-recolonization dynamics of the disease. In the light of these results, we suggest scenarios to explain the localized presence of plague in Madagascar.

  14. Host Resistance, Population Structure and the Long-Term Persistence of Bubonic Plague: Contributions of a Modelling Approach in the Malagasy Focus

    Science.gov (United States)

    Gascuel, Fanny; Choisy, Marc; Duplantier, Jean-Marc; Débarre, Florence; Brouat, Carine

    2013-01-01

    Although bubonic plague is an endemic zoonosis in many countries around the world, the factors responsible for the persistence of this highly virulent disease remain poorly known. Classically, the endemic persistence of plague is suspected to be due to the coexistence of plague resistant and plague susceptible rodents in natural foci, and/or to a metapopulation structure of reservoirs. Here, we test separately the effect of each of these factors on the long-term persistence of plague. We analyse the dynamics and equilibria of a model of plague propagation, consistent with plague ecology in Madagascar, a major focus where this disease is endemic since the 1920s in central highlands. By combining deterministic and stochastic analyses of this model, and including sensitivity analyses, we show that (i) endemicity is favoured by intermediate host population sizes, (ii) in large host populations, the presence of resistant rats is sufficient to explain long-term persistence of plague, and (iii) the metapopulation structure of susceptible host populations alone can also account for plague endemicity, thanks to both subdivision and the subsequent reduction in the size of subpopulations, and extinction-recolonization dynamics of the disease. In the light of these results, we suggest scenarios to explain the localized presence of plague in Madagascar. PMID:23675291

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

    Science.gov (United States)

    Wang, Xin; Wei, Xiaoyu; Song, Zhizhong; Wang, Mingliu; Xi, Jinxiao; Liang, Junrong; Liang, Yun; Duan, Ran; Tian, Kecheng; Zhao, Yong; Tang, Guangpeng; You, Lv; Yang, Guirong; Liu, Xuebin; Chen, Yuhuang; Zeng, Jun; Wu, Shengrong; Luo, Shoujun; Qin, Gang; Hao, Huijing; Jing, Huaiqi

    2017-03-01

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

  16. Host resistance, population structure and the long-term persistence of bubonic plague: contributions of a modelling approach in the Malagasy focus.

    Directory of Open Access Journals (Sweden)

    Fanny Gascuel

    Full Text Available Although bubonic plague is an endemic zoonosis in many countries around the world, the factors responsible for the persistence of this highly virulent disease remain poorly known. Classically, the endemic persistence of plague is suspected to be due to the coexistence of plague resistant and plague susceptible rodents in natural foci, and/or to a metapopulation structure of reservoirs. Here, we test separately the effect of each of these factors on the long-term persistence of plague. We analyse the dynamics and equilibria of a model of plague propagation, consistent with plague ecology in Madagascar, a major focus where this disease is endemic since the 1920s in central highlands. By combining deterministic and stochastic analyses of this model, and including sensitivity analyses, we show that (i endemicity is favoured by intermediate host population sizes, (ii in large host populations, the presence of resistant rats is sufficient to explain long-term persistence of plague, and (iii the metapopulation structure of susceptible host populations alone can also account for plague endemicity, thanks to both subdivision and the subsequent reduction in the size of subpopulations, and extinction-recolonization dynamics of the disease. In the light of these results, we suggest scenarios to explain the localized presence of plague in Madagascar.

  17. Colorado animal-based plague surveillance systems: relationships between targeted animal species and prediction efficacy of areas at risk for humans.

    Science.gov (United States)

    Lowell, Jennifer L; Eisen, Rebecca J; Schotthoefer, Anna M; Xiaocheng, Liang; Montenieri, John A; Tanda, Dale; Pape, John; Schriefer, Martin E; Antolin, Michael F; Gage, Kenneth L

    2009-06-01

    Human plague risks (Yersinia pestis infection) are greatest when epizootics cause high mortality among this bacterium's natural rodent hosts. Therefore, health departments in plague-endemic areas commonly establish animal-based surveillance programs to monitor Y. pestis infection among plague hosts and vectors. The primary objectives of our study were to determine whether passive animal-based plague surveillance samples collected in Colorado from 1991 to 2005 were sampled from high human plague risk areas and whether these samples provided information useful for predicting human plague case locations. By comparing locations of plague-positive animal samples with a previously constructed GIS-based plague risk model, we determined that the majority of plague-positive Gunnison's prairie dogs (100%) and non-prairie dog sciurids (85.82%), and moderately high percentages of sigmodontine rodents (71.4%), domestic cats (69.3%), coyotes (62.9%), and domestic dogs (62.5%) were recovered within 1 km of the nearest area posing high peridomestic risk to humans. In contrast, the majority of white-tailed prairie dog (66.7%), leporid (cottontailed and jack rabbits) (71.4%), and black-tailed prairie dog (93.0%) samples originated more than 1 km from the nearest human risk habitat. Plague-positive animals or their fleas were rarely (one of 19 cases) collected within 2 km of a case exposure site during the 24 months preceding the dates of illness onset for these cases. Low spatial accuracy for identifying epizootic activity prior to human plague cases suggested that other mammalian species or their fleas are likely more important sources of human infection in high plague risk areas. To address this issue, epidemiological observations and multi-locus variable number tandem repeat analyses (MLVA) were used to preliminarily identify chipmunks as an under-sampled, but potentially important, species for human plague risk in Colorado.

  18. Integrating land cover and terrain characteristics to explain plague risks in Western Usambara Mountains, Tanzania: a geospatial approach.

    Science.gov (United States)

    Hieronimo, Proches; Meliyo, Joel; Gulinck, Hubert; Kimaro, Didas N; Mulungu, Loth S; Kihupi, Nganga I; Msanya, Balthazar M; Leirs, Herwig; Deckers, Jozef A

    2014-07-01

    Literature suggests that higher resolution remote sensing data integrated in Geographic Information System (GIS) can provide greater possibility to refine the analysis of land cover and terrain characteristics for explanation of abundance and distribution of plague hosts and vectors and hence of health risk hazards to humans. These technologies are not widely used in East Africa for studies on diseases including plague. The objective of this study was to refine the analysis of single and combined land cover and terrain characteristics in order to gain an insight into localized plague infection risks in the West Usambara Mountains in north-eastern Tanzania. The study used a geospatial approach to assess the influence of land cover and terrain factors on the abundance and spatial distribution of plague hosts (small mammals) and plague vectors (fleas). It considered different levels of scale and resolution. Boosted Regression Tree (BRT) statistical method was used to clarify the relationships between land cover and terrain variables with small mammals and fleas. Results indicate that elevation positively influenced the presence of small mammals. The presence of fleas was clearly influenced by land management features such as miraba. Medium to high resolution remotely sensed data integrated in a GIS have been found to be quite useful in this type of analysis. These findings contribute to efforts on plague surveillance and awareness creation among communities on the probable risks associated with various landscape factors during epidemics.

  19. Spatial prediction and analysis of Himalayan marmot plague natural epidemic foci in China based on HJ-1 satellite data

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Plague,caused by the gram-negative bacterium Yersinia pestis,is a serious and rapidly progressing illness in humans that can be fatal if not treated effectively.The Qinghai-Tibet Plateau is the largest area of natural Himalayan marmot(Marmota himalayana) plague foci in China and covers more than 630000 km2.Akesai County in Gansu Province is a part of this natural focus of plague and was chosen as a study area.Our study used an ecological niche modeling(ENM) approach to predict the potential distribution of the Himalayan marmot.Environment and Disaster Monitor Satellite(HJ-1) data was used to investigate environment factors that affect plague host animal activity.Host animal point data from active surveillance was combined with environmental variables from the HJ-1 satellite and other databases,and the models of the potential distribution of Himalayan marmot were produced with the Genetic Algorithm for Rule-Set Production(GARP).The probability of marmot presence was divided into 0-5%,5%-20%,20%-40%,40%-80%,and 80%-100% subgroups.Areas with 80%-100% probability exhibited the greatest potential for the presence of Himalayan marmot.According to the predicted potential distribution of Himalayan marmot in the study area,active surveillance of plague hosts and plague control and prevention could be more efficient.

  20. [The black rat (Rattus rattus) and the plague in ancient and medieval western Europe].

    Science.gov (United States)

    Audoin-Rouzeau, F

    1999-12-01

    The first time plague affected Western Europe was in the early Middle Ages: rom 541 to 767, there were no fewer than 15 outbreaks in southern parts of the continent. Plague then disappeared from Europe for some seven centuries but came back with a vengeance in 1347, this time by way of the Mediterranean, and ravaged the entire continent for five years, resulting in a serious demographic depression. From then on until 1722 (and 1771 in Moscow), the disease remained endemic to Europe, periodically undermining its economy. These epidemics were major determinants of medieval history, but their study has not been completed to this day. It was not until the 1970s that archeo-zoologists finally discovered that the black rat had indeed been present in Europe since Roman times. Further extensive research revealed that the rat population had gradually grown from a fairly restricted one in the early Middle Ages to a significant one in the 11th and 13th centuries. The rodents spread along the major highways explaining the very different geographical impact of the various plague epidemics of the early and late medieval periods. However, the mystery of the exact mechanisms by which plague spread has still not been entirely elucidated, since the Asian rat flea, Xenopsylla cheopis, whose role as vector was demonstrated by P. L. Simond, could not have survived in the temperate European climate. Thus, the question of the European vector is still left hanging: was it a human or a rat flea? Was the rat a propagator or simply an initiator? This article considers these unresolved questions by re-examining P. L. Simond's very precise observations.

  1. Prediction of Frost Risks and Plagues using WRF model: a Port Wine region case study

    Science.gov (United States)

    Rodrigues, M. A.; Rocha, A.; Monteiro, A.; Quénol, H.; de Freitas, J. R.

    2012-04-01

    In viticulture where the quality of the wine, the selection of the grapevines or even the characteristics of the farming soil, also depending from local soil features like topography, proximity of a river or water body, will act locally on the weather. Frosts are of significant concern to growers of many cultures crops such as winegrapes. Because of their high latitude and some altitude, the vineyards of the Demarcated Douro Region (DDR) are subjected to the frost, which cause serious damages. But the hazards of vineyard don't confine to the incidents of the fortuitous and meteorological character. The illnesses and plagues affect frequently the vineyards of Demarcated Douro Region due, namely to the weather, to the high power of the regional stocks, to the dense vegetation badly drained and favourable to the setting of numberless fungi, viruses and/or poisonous insects. In the case of DDR it is worth noticing the meteorological conditions due to the weather characteristics. Although there are several illnesses and plagues the most important enemies for the vine in the DDR are the mildew, oidium, grey rottenness, grape moth,. . . , if the climatic conditions favour their appearance and development. For this study, we selected some months for different periods, at the 16 weather stations of the Region of Douro. We use the Weather Research and Forecast Model (WRF) to study and possibly predict the occurrence of risk and plagues (mildew) episodes. The model is first validated with the meteorological data obtained at the weather stations. The knowledge of frost and plagues occurrence allows one to decrease its risks not only by selecting the cultural species and varieties but also the places of growth and the planting and sowing dates.

  2. SAP R/3 An IT-plague or the answer to the Tailors dream?

    DEFF Research Database (Denmark)

    Koch, Christian

    1999-01-01

    The IT-market of ERP-systems have significantly changed over the last 10 years. At least in Denmark manufacturing enterprises used to close "partner like" collaboration with their IT-supplier, now face mass produced packaged software. This challenges the skills of technology managers, can they co...... with the IT-plague, do they suffer from the "power of default",i.e. the use of standard settings of parameters?- or can they tailor anything to anybody?...

  3. Transcriptomic and innate immune responses to Yersinia pestis in the lymph node during bubonic plague.

    Science.gov (United States)

    Comer, Jason E; Sturdevant, Daniel E; Carmody, Aaron B; Virtaneva, Kimmo; Gardner, Donald; Long, Dan; Rosenke, Rebecca; Porcella, Stephen F; Hinnebusch, B Joseph

    2010-12-01

    A delayed inflammatory response is a prominent feature of infection with Yersinia pestis, the agent of bubonic and pneumonic plague. Using a rat model of bubonic plague, we examined lymph node histopathology, transcriptome, and extracellular cytokine levels to broadly characterize the kinetics and extent of the host response to Y. pestis and how it is influenced by the Yersinia virulence plasmid (pYV). Remarkably, dissemination and multiplication of wild-type Y. pestis during the bubonic stage of disease did not induce any detectable gene expression or cytokine response by host lymph node cells in the developing bubo. Only after systemic spread had led to terminal septicemic plague was a transcriptomic response detected, which included upregulation of several cytokine, chemokine, and other immune response genes. Although an initial intracellular phase of Y. pestis infection has been postulated, a Th1-type cytokine response associated with classical activation of macrophages was not observed during the bubonic stage of disease. However, elevated levels of interleukin-17 (IL-17) were present in infected lymph nodes. In the absence of pYV, sustained recruitment to the lymph node of polymorphonuclear leukocytes (PMN, or neutrophils), the major IL-17 effector cells, correlated with clearance of infection. Thus, the ability to counteract a PMN response in the lymph node appears to be a major in vivo function of the Y. pestis virulence plasmid.

  4. Flea-borne transmission model to evaluate vaccine efficacy against naturally acquired bubonic plague.

    Science.gov (United States)

    Jarrett, Clayton O; Sebbane, Florent; Adamovicz, Jeffrey J; Andrews, Gerard P; Hinnebusch, B Joseph

    2004-04-01

    A flea-to-mouse transmission model was developed for use in testing new candidate vaccines for the ability to protect against flea-borne plague. The model was used to evaluate a recombinant fusion protein vaccine consisting of the Yersinia pestis F1 and V antigens. After one to three challenges with Y. pestis-infected fleas, 14 of 15 unvaccinated control mice developed plague, with an average septicemia level of 9.2 x 10(8) Y. pestis CFU/ml. None of 15 vaccinated mice developed the disease after similar challenges, and serological testing indicated that transmitted bacteria were eliminated by the immune system before extensive replication and systemic infection could occur. The transmission and development of disease in control mice correlated with the number of bites by blocked fleas but not with the total number of fleabites. The model provides a means to directly assess the efficacy of new vaccines to prevent naturally acquired bubonic plague and to study events at the vector-host interface that lead to dissemination and disease.

  5. The plague fighter: Wu Lien-teh and the beginning of the Chinese public health system.

    Science.gov (United States)

    Flohr, C

    1996-07-01

    At the end of 1910, when the Qing dynasty was on the verge of collapse and the whole Chinese empire in a process of transformation, North Manchuria was devastated by a large pneumonic plague epidemic. The Russian and Japanese governments wanted to use the outbreak of the disease as a pretext to invade north-east China, making plague an issue of international politics. At this dramatic moment the empire relied on the skills of the young Chinese doctor Wu Lien-teh, the first Chinese medical graduate from Cambridge. Wu investigated the disease on the spot, chaired an international plague conference in Shenyang (Manchuria) in April 1911, and, later on, became the figurehead of fundamental public health reforms in Republican China. Highly ambitious, striving for personal fame and international renown for China, supported by an excellent network of personal connections, and equipped with a medical training considered the best in the world at the time, he launched on a startling career as one of China's key medical reformers and international representatives. His history is an example of the inseparable links between personal fate and historical events, and between the interests of scientists, medical men, politicians, and businessmen on the national and international stages.

  6. Multiple mechanisms of transmission of the Caribbean coral disease white plague

    Science.gov (United States)

    Clemens, E.; Brandt, M. E.

    2015-12-01

    White plague is one of the most devastating coral diseases in the Caribbean, and yet important aspects of its epidemiology, including how the disease transmits, remain unknown. This study tested potential mechanisms and rates of transmission of white plague in a laboratory setting. Transmission mechanisms including the transport of water, contact with macroalgae, and predation via corallivorous worms and snails were tested on the host species Orbicella annularis. Two of the tested mechanisms were shown to transmit disease: water transport and the corallivorous snail Coralliophila abbreviata. Between these transmission mechanisms, transport of water between a diseased coral and a healthy coral resulted in disease incidence significantly more frequently in exposed healthy corals. Transmission via water transport also occurred more quickly and was associated with higher rates of tissue loss (up to 3.5 cm d-1) than with the corallivorous snail treatment. In addition, water that was in contact with diseased corals but was filtered with a 0.22-μm filter prior to being introduced to apparently healthy corals also resulted in the transmission of disease signs, but at a much lower rate than when water was not filtered. This study has provided important information on the transmission potential of Caribbean white plague disease and highlights the need for a greater understanding of how these processes operate in the natural environment.

  7. Inhaled Liposomal Ciprofloxacin Protects against a Lethal Infection in a Murine Model of Pneumonic Plague

    Science.gov (United States)

    Hamblin, Karleigh A.; Armstrong, Stuart J.; Barnes, Kay B.; Davies, Carwyn; Laws, Thomas; Blanchard, James D.; Harding, Sarah V.; Atkins, Helen S.

    2017-01-01

    Inhalation of Yersinia pestis can lead to pneumonic plague, which without treatment is inevitably fatal. Two novel formulations of liposome-encapsulated ciprofloxacin, ‘ciprofloxacin for inhalation’ (CFI, Lipoquin®) and ‘dual release ciprofloxacin for inhalation’ (DRCFI, Pulmaquin®) containing CFI and ciprofloxacin solution, are in development. These were evaluated as potential therapies for infection with Y. pestis. In a murine model of pneumonic plague, human-like doses of aerosolized CFI, aerosolized DRCFI or intraperitoneal (i.p.) ciprofloxacin were administered at 24 h (representing prophylaxis) or 42 h (representing treatment) post-challenge. All three therapies provided a high level of protection when administered 24 h post-challenge. A single dose of CFI, but not DRCFI, significantly improved survival compared to a single dose of ciprofloxacin. Furthermore, single doses of CFI and DRCFI reduced bacterial burden in lungs and spleens to below the detectable limit at 60 h post-challenge. When therapy was delayed until 42 h post-challenge, a single dose of CFI or DRCFI offered minimal protection. However, single doses of CFI or DRCFI were able to significantly reduce the bacterial burden in the spleen compared to empty liposomes. A three-day treatment regimen of ciprofloxacin, CFI, or DRCFI resulted in high levels of protection (90–100% survival). This study suggests that CFI and DRCFI may be useful therapies for Y. pestis infection, both as prophylaxis and for the treatment of plague. PMID:28220110

  8. Investigation of vesicle-capsular plague antigen complex formation by elastic laser radiation scattering

    Science.gov (United States)

    Guseva, N. P.; Maximova, Irina S.; Romanov, Sergey V.; Shubochkin, L. P.; Tatarintsev, Sergey N.

    1991-05-01

    Recently a great deal of attention has been given to the investigation artificial lipid liposomes, due to their application as "containers" for directed transport of biologically active compounds into particular cells, organs and tissues for prophylaxis and therapy of infectious diseases. The use of traditional methods of liposome investigation, such as sedimentation, electrophoresis and chromatography is impeded by low liposome resistivity to different deformations. In conjunction with this, optical methods of laser light scattering are promising as they allow nondisturbing, precise and quick investigations. This paper describes the investigation of vesicle systems prepared from egg lecithin of Serva Corporation and their complexes with the capsular antigen of the plague microbe. The capsular antigen Fl was obtained from EV plague microbe grown at 37° C on Huttinger agar. Fl was isolated by gel-filtration on ASA-22 followed by freeze drying of the preparation. Angular dependences of polarized radiation scattering were measured for several liposome suspension samples in a saline solution before and after the interaction with the plague microbe capsular antigen. The aim of the investigation was to analyze the nature of mutual antigen arrangement in a liposome and to develop methods for measuring its inclusion percentage.

  9. A rapid field test for sylvatic plague exposure in wild animals.

    Science.gov (United States)

    Abbott, Rachel C; Hudak, Robert; Mondesire, Roy; Baeten, Laurie A; Russell, Robin E; Rocke, Tonie E

    2014-04-01

    Plague surveillance is routinely conducted to predict future epizootics in wildlife and exposure risk for humans. The most common surveillance method for sylvatic plague is detection of antibodies to Yersinia pestis F1 capsular antigen in sentinel animals, such as coyotes (Canis latrans). Current serologic tests for Y. pestis, hemagglutination (HA) test and enzyme-linked immunosorbent assay (ELISA), are expensive and labor intensive. To address this need, we developed a complete lateral flow device for the detection of specific antibodies to Y. pestis F1 and V antigens. Our test detected anti-F1 and anti-V antibodies in serum and Nobuto filter paper samples from coyotes, and in serum samples from prairie dogs (Cynomys ludovicianus), lynx (Lynx canadensis), and black-footed ferrets (Mustela nigripes). Comparison of cassette results for anti-F1 and anti-V antibodies with results of ELISA or HA tests showed correlations ranging from 0.68 to 0.98. This device provides an affordable, user-friendly tool that may be useful in plague surveillance programs and as a research tool.

  10. Unreliability and the Animal Narrator in Richard Adams’s The Plague Dogs

    Directory of Open Access Journals (Sweden)

    Anja Höing

    2017-03-01

    Full Text Available Richard Adams’s talking animal story The Plague Dogs (1978, with its deeply genre-atypical mode of narration, offers a multiplicity of avenues to explore the literary animal as animal. The story draws much of its power from the psychological complexity and related unreliability of both canine narrators, two research lab escapees gone feral. Both the terrier Snitter and the black mongrel Rowf are mentally ill and experience a highly subjective, part-fantastic world. In episodes of zero focalization, a sarcastic voice comments on the plot from the off, aggressively attacking a thoroughly anthropocentric superstructure the protagonists themselves are oblivious of, and presenting all that is normally constructed as “rational” in the implied reader’s world as a carnivalesque farce. Combining these equally unreliable narratives, The Plague Dogs creates a unique mixture of what Phelan (2007 calls “estranging” and “bonding” unreliability and brings to light the devastating consequences of anthropocentrism. The Plague Dogs not only defamiliarizes a genre usually committed to conventional means of storytelling, but the dominant Western conception of the status of animals in the world, showing that once we start to read the animal as animal, this sets into motion an avalanche of other concepts in need of re-reading, among them the very ones making up the fundamental pillars of Western societies’ anthropocentric self-conception.

  11. Immunization of black-tailed prairie dog against plague through consumption of vaccine-laden baits.

    Science.gov (United States)

    Rocke, Tonie E; Smith, Susan R; Stinchcomb, Dan T; Osorio, Jorge E

    2008-10-01

    Prairie dogs (Cynomys spp.) are highly susceptible to Yersinia pestis and, along with other wild rodents, are significant reservoirs of plague for other wildlife and humans in the western United States. A recombinant raccoon poxvirus, expressing the F1 antigen of Y. pestis, was incorporated into a palatable bait and offered to three groups (n = 18, 19, and 20) of black-tailed prairie dogs (Cynomys ludovicianus) for voluntary consumption, either one, two, or three times, at roughly 3-wk intervals. A control group (n = 19) received baits containing raccoon poxvirus without the inserted antigen. Mean antibody titers to Y. pestis F1 antigen increased significantly in all groups ingesting the vaccine-laden baits, whereas the control group remained negative. Upon challenge with virulent Y. pestis, immunized groups had higher survival rates (38%) than the unimmunized control group (11%). The mean survival time of groups ingesting vaccine-laden baits either two or three times was significantly higher than that of animals ingesting vaccine-laden baits just one time and of animals in the control group. These results show that oral immunization of prairie dogs against plague provides some protection against challenge at dosages that simulate simultaneous delivery of the plague bacterium by numerous (3-10) flea bites.

  12. Impact of the Pla protease substrate α2-antiplasmin on the progression of primary pneumonic plague.

    Science.gov (United States)

    Eddy, Justin L; Schroeder, Jay A; Zimbler, Daniel L; Bellows, Lauren E; Lathem, Wyndham W

    2015-12-01

    Many pathogens usurp the host hemostatic system during infection to promote pathogenesis. Yersinia pestis, the causative agent of plague, expresses the plasminogen activator protease Pla, which has been shown in vitro to target and cleave multiple proteins within the fibrinolytic pathway, including the plasmin inhibitor α2-antiplasmin (A2AP). It is not known, however, if Pla inactivates A2AP in vivo; the role of A2AP during respiratory Y. pestis infection is not known either. Here, we show that Y. pestis does not appreciably cleave A2AP in a Pla-dependent manner in the lungs during experimental pneumonic plague. Furthermore, following intranasal infection with Y. pestis, A2AP-deficient mice exhibit no difference in survival time, bacterial burden in the lungs, or dissemination from wild-type mice. Instead, we found that in the absence of Pla, A2AP contributes to the control of the pulmonary inflammatory response during infection by reducing neutrophil recruitment and cytokine production, resulting in altered immunopathology of the lungs compared to A2AP-deficient mice. Thus, our data demonstrate that A2AP is not significantly affected by the Pla protease during pneumonic plague, and although A2AP participates in immune modulation in the lungs, it has limited impact on the course or ultimate outcome of the infection.

  13. Immuno-PCR--a new tool for paleomicrobiology: the plague paradigm.

    Directory of Open Access Journals (Sweden)

    Nada Malou

    Full Text Available BACKGROUND: The cause of past plague pandemics was controversial but several research teams used PCR techniques and dental pulp as the primary material to reveal that they were caused by Yersinia pestis. However, the degradation of DNA limits the ability to detect ancient infections. METHODS: We used for the first time immuno-PCR to detect Yersinia pestis antigens; it can detect protein concentrations 70 times lower than the standard ELISA. After determining the cut-off value, we tested 34 teeth that were obtained from mass graves of plague, and compared previous PCR results with ELISA and immuno-PCR results. RESULTS: The immuno-PCR technique was the most sensitive (14 out of 34 followed by the PCR technique (10 out of 34 and ELISA (3 out of 34. The combination of these three methods identified 18 out of 34 (53% teeth as presumably being from people with the plague. CONCLUSION: Immuno-PCR is specific (no false-positive samples were found and more sensitive than the currently used method to detect antigens of ancient infections in dental pulp. The combination of three methods, ELISA, PCR and immuno-PCR, increased the capacity to identify ancient pathogens in dental pulp.

  14. Immuno-PCR - A New Tool for Paleomicrobiology: The Plague Paradigm

    Science.gov (United States)

    Nappez, Claude; Signoli, Michel; Le Forestier, Cyrille; Castex, Dominique; Drancourt, Michel; Raoult, Didier

    2012-01-01

    Background The cause of past plague pandemics was controversial but several research teams used PCR techniques and dental pulp as the primary material to reveal that they were caused by Yersinia pestis. However, the degradation of DNA limits the ability to detect ancient infections. Methods We used for the first time immuno-PCR to detect Yersinia pestis antigens; it can detect protein concentrations 70 times lower than the standard ELISA. After determining the cut-off value, we tested 34 teeth that were obtained from mass graves of plague, and compared previous PCR results with ELISA and immuno-PCR results. Results The immuno-PCR technique was the most sensitive (14 out of 34) followed by the PCR technique (10 out of 34) and ELISA (3 out of 34). The combination of these three methods identified 18 out of 34 (53%) teeth as presumably being from people with the plague. Conclusion Immuno-PCR is specific (no false-positive samples were found) and more sensitive than the currently used method to detect antigens of ancient infections in dental pulp. The combination of three methods, ELISA, PCR and immuno-PCR, increased the capacity to identify ancient pathogens in dental pulp. PMID:22347507

  15. Controlling Ebola: what we can learn from China's 1911 battle against the pneumonic plague in Manchuria.

    Science.gov (United States)

    Liu, He; Jiao, Mingli; Zhao, Siqi; Xing, Kai; Li, Ye; Ning, Ning; Liang, Libo; Wu, Qunhong; Hao, Yanhua

    2015-04-01

    The pneumonic plague, which spread across Northeast China during the winter of 1910 and spring of 1911, caused numerous deaths and brought about severe social turmoil. After compulsory quarantine and other epidemic prevention measures were enforced by Dr Wu Lien-teh, the epidemic was brought to an end within 4 months. This article reviews the ways in which the plague was dealt with from a historical perspective, based on factors such as clinical manifestations, duration of illness, case fatality rate, degree of transmissibility, poverty, inadequate healthcare infrastructure, and the region's recent strife-filled history. Similarities were sought between the pneumonic plague in Northeast China in the twentieth century and the Ebola virus outbreak that is currently ravaging Africa, and an effort made to summarize the ways in which specific measures were applied successfully to fight the earlier epidemic. Our efforts highlight valuable experiences that are of potential benefit in helping to fight the current rampant Ebola epidemic in West Africa. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  16. A rapid field test for sylvatic plague exposure in wild animals

    Science.gov (United States)

    Abbott, Rachel C.; Hudak, Robert; Mondesire, Roy; Baeten, Laurie A.; Russell, Robin E.; Rocke, Tonie E.

    2014-01-01

    Plague surveillance is routinely conducted to predict future epizootics in wildlife and exposure risk for humans. The most common surveillance method for sylvatic plague is detection of antibodies to Yersinia pestis F1 capsular antigen in sentinel animals, such as coyotes (Canis latrans). Current serologic tests for Y. pestis, hemagglutination (HA) test and enzyme-linked immunosorbent assay (ELISA), are expensive and labor intensive. To address this need, we developed a complete lateral flow device for the detection of specific antibodies to Y. pestis F1 and V antigens. Our test detected anti-F1 and anti-V antibodies in serum and Nobuto filter paper samples from coyotes, and in serum samples from prairie dogs (Cynomys ludovicianus), lynx (Lynx canadensis), and black-footed ferrets (Mustela nigripes). Comparison of cassette results for anti-F1 and anti-V antibodies with results of ELISA or HA tests showed correlations ranging from 0.68 to 0.98. This device provides an affordable, user-friendly tool that may be useful in plague surveillance programs and as a research tool.

  17. Immunization of black-tailed prairie dog against plague through consumption of vaccine-laden baits

    Science.gov (United States)

    Rocke, T.E.; Smith, S.R.; Stinchcomb, D.T.; Osorio, J.E.

    2008-01-01

    Prairie dogs (Cynomys spp.) are highly susceptible to Yersinia pestis and, along with other wild rodents, are significant reservoirs of plague for other wildlife and humans in the western United States. A recombinant raccoon poxvirus, expressing the F1 antigen of Y. pestis, was incorporated into a palatable bait and offered to three groups (n = 18, 19, and 20) of black-tailed prairie dogs (Cynomys ludovicianus) for voluntary consumption, either one, two, or three times, at roughly 3-wk intervals. A control group (n = 19) received baits containing raccoon poxvirus without the inserted antigen. Mean antibody titers to Y. pestis F1 antigen increased significantly in all groups ingesting the vaccine-laden baits, whereas the control group remained negative. Upon challenge with virulent Y. pestis, immunized groups had higher survival rates (38%) than the unimmunized control group (11%). The mean survival time of groups ingesting vaccine-laden baits either two or three times was significantly higher than that of animals ingesting vaccine-laden baits just one time and of animals in the control group. These results show that oral immunization of prairie dogs against plague provides some protection against challenge at dosages that simulate simultaneous delivery of the plague bacterium by numerous (3-10) flea bites. ?? Wildlife Disease Association 2008.

  18. First evidence of crayfish plague agent in populations of the marbled crayfish (Procambarus fallax forma virginalis

    Directory of Open Access Journals (Sweden)

    Keller N.S.

    2014-01-01

    Full Text Available The introduction of non-indigenous species and associated diseases can cause declines in indigenous flora and fauna and threaten local biodiversity. The crayfish plague pathogen (Aphanomyces astaci, carried and transmitted by latent infected North American crayfish, can lead to high mortalities in indigenous European crayfish populations. Although the parthenogenetic marbled crayfish (Procambarus fallax (Hagen, 1870  forma virginalis is common in the aquarium trade and has established wild populations in Europe, its carrier status is still unknown. This study investigated one captive and three established wild-living marbled crayfish populations for an infection with the crayfish plague pathogen applying real-time PCR. We demonstrate that captive, as well as two wild marbled crayfish populations were infected by A. astaci. Although infection status in laboratory kept specimens reached high levels, marbled crayfish showed no obviously plague-related mortality. Furthermore, sequence analysis revealed that captive crayfish carried the A. astaci genotype Pc, which has earlier been isolated from the North American red swamp crayfish (Procambarus clarkii. The results indicate that due to its positive carrier status marbled crayfish poses a greater threat to local biodiversity in Europe than considered until now.

  19. Controlling Ebola: what we can learn from China's 1911 battle against the pneumonic plague in Manchuria

    Directory of Open Access Journals (Sweden)

    He Liu

    2015-04-01

    Full Text Available The pneumonic plague, which spread across Northeast China during the winter of 1910 and spring of 1911, caused numerous deaths and brought about severe social turmoil. After compulsory quarantine and other epidemic prevention measures were enforced by Dr Wu Lien-teh, the epidemic was brought to an end within 4 months. This article reviews the ways in which the plague was dealt with from a historical perspective, based on factors such as clinical manifestations, duration of illness, case fatality rate, degree of transmissibility, poverty, inadequate healthcare infrastructure, and the region's recent strife-filled history. Similarities were sought between the pneumonic plague in Northeast China in the twentieth century and the Ebola virus outbreak that is currently ravaging Africa, and an effort made to summarize the ways in which specific measures were applied successfully to fight the earlier epidemic. Our efforts highlight valuable experiences that are of potential benefit in helping to fight the current rampant Ebola epidemic in West Africa.

  20. The plagues of Egypt: what killed the animals and the firstborn?

    Science.gov (United States)

    Hoyte, H M

    1993-05-17

    The Book of Exodus, various translations, chapters 7 to 12--The plagues: 1. The river Nile turned the colour of blood, the water stank and the fish died 2. Hordes of frogs left the river, then they died and their bodies stank 3. Swarms of gnats attacked the people and their animals 4. Swarms of flies then did the same 5. An epidemic disease killed many farm animals 6. Boils and skin sores broke out on the people and their animals 7. A violent hail storm ruined the crops 8. A swarm of locusts ate what was left of them 9. Darkness blanketed the country for three days 10. The eldest child in each family died suddenly, and so did the first born animals. THE PERIOD: Uncertain, but deduced to be about 1470 BC. THE PEOPLE: The Egyptians, a population of about 2.5 million, about one million living in the Nile delta at an average density of about 90 people per km2 of cultivated land, and the Israelites, working as slave-labourers and quartered in the land of Goshen, a relatively small area probably near the margin of the north-east part of the Nile delta. THE PROTAGONISTS: Thutmosis III, Pharoah of Egypt, and Moses, leader of the Israelites. THE PLACE: The encounters between Thutmosis and Moses occurred just before each of the plagues, in or close to the Pharoah's palace. Given Moses' location, this must have been the palace at Memphis, the old capital, near the southern apex or beginning of the delta, not the one at Thebes, 600 km further to the south along the river. The Israelites' perception of the geographical extent of the plagues was therefore limited to what happened in the delta. The statements that plagues 1, 2, 3 and 8 affected "all the land of Egypt" should be interpreted as: all of the Nile delta including the land of Goshen. The other plagues affected parts neighbouring on, but not including, the land of Goshen.

  1. Glutathionylation of Yersinia pestis LcrV and Its Effects on Plague Pathogenesis.

    Science.gov (United States)

    Mitchell, Anthony; Tam, Christina; Elli, Derek; Charlton, Thomas; Osei-Owusu, Patrick; Fazlollahi, Farbod; Faull, Kym F; Schneewind, Olaf

    2017-05-16

    Glutathionylation, the formation of reversible mixed disulfides between glutathione and protein cysteine residues, is a posttranslational modification previously observed for intracellular proteins of bacteria. Here we show that Yersinia pestis LcrV, a secreted protein capping the type III secretion machine, is glutathionylated at Cys(273) and that this modification promotes association with host ribosomal protein S3 (RPS3), moderates Y. pestis type III effector transport and killing of macrophages, and enhances bubonic plague pathogenesis in mice and rats. Secreted LcrV was purified and analyzed by mass spectrometry to reveal glutathionylation, a modification that is abolished by the codon substitution Cys(273)Ala in lcrV Moreover, the lcrVC273A mutation enhanced the survival of animals in models of bubonic plague. Investigating the molecular mechanism responsible for these virulence attributes, we identified macrophage RPS3 as a ligand of LcrV, an association that is perturbed by the Cys(273)Ala substitution. Furthermore, macrophages infected by the lcrVC273A variant displayed accelerated apoptotic death and diminished proinflammatory cytokine release. Deletion of gshB, which encodes glutathione synthetase of Y. pestis, resulted in undetectable levels of intracellular glutathione, and we used a Y. pestis ΔgshB mutant to characterize the biochemical pathway of LcrV glutathionylation, establishing that LcrV is modified after its transport to the type III needle via disulfide bond formation with extracellular oxidized glutathione.IMPORTANCEYersinia pestis, the causative agent of plague, has killed large segments of the human population; however, the molecular bases for the extraordinary virulence attributes of this pathogen are not well understood. We show here that LcrV, the cap protein of bacterial type III secretion needles, is modified by host glutathione and that this modification contributes to the high virulence of Y. pestis in mouse and rat models for

  2. Persistence of black-tailed prairie-dog populations affected by plague in northern Colorado, USA.

    Science.gov (United States)

    George, Dylan B; Webb, Colleen T; Pepin, Kim M; Savage, Lisa T; Antolini, Michael F

    2013-07-01

    The spatial distribution of prairie dog (Cynomys ludovicianus) colonies in North America has changed from large, contiguous populations to small, isolated colonies in metapopulations. One factor responsible for this drastic change in prairie-dog population structure is plague (caused by the bacterium Yersinia pestis). We fit stochastic patch occupancy models to 20 years of prairie-dog colony occupancy data from two discrete metapopulations (west and east) in the Pawnee National Grassland in Colorado, USA, that differ in connectivity among suitable habitat patches. We conducted model selection between two hypothesized modes of plague movement: independent of prairie-dog dispersal (colony-area) vs. plague movement consistent with prairie-dog dispersal (connectivity to extinct colonies). The best model, which fit the data well (area under the curve [AUC]: 0.94 west area; 0.79 east area), revealed that over time the proportion of extant colonies was better explained by colony size than by connectivity to extinct (plagued) colonies. The idea that prairie dogs are not likely to be the main vector that spreads Y. pestis across the landscape is supported by the observation that colony extinctions are primarily caused by plague, prairie-dog dispersal is short range, and connectivity to extinct colonies was not selected as a factor in the models. We also conducted simulations with the best model to examine long-term patterns of colony occupancy and persistence of prairie-dog metapopulations. In the case where the metapopulations persist, our model predicted that the western metapopulation would have a colony occupancy rate approximately 2.5 times higher than that of the eastern metapopulation (-50% occupied colonies vs. 20%) in 50 years, but that the western metapopulation has -80% chance of extinction in 100 years while the eastern metapopulation has a less than 25% chance. Extinction probability of individual colonies depended on the frequency with which colonies of the

  3. Use of a public telephone hotline to detect urban plague cases.

    Science.gov (United States)

    Malberg, J A; Pape, W J; Lezotte, D; Hill, A E

    2012-11-01

    Current methods for vector-borne disease surveillance are limited by time and cost. To avoid human infections from emerging zoonotic diseases, it is important that the United States develop cost-effective surveillance systems for these diseases. This study examines the methodology used in the surveillance of a plague epizootic involving tree squirrels (Sciurus niger) in Denver Colorado, during the summer of 2007. A call-in centre for the public to report dead squirrels was used to direct animal carcass sampling. Staff used these reports to collect squirrel carcasses for the analysis of Yersinia pestis infection. This sampling protocol was analysed at the census tract level using Poisson regression to determine the relationship between higher call volumes in a census tract and the risk of a carcass in that tract testing positive for plague. Over-sampling owing to call volume-directed collection was accounted for by including the number of animals collected as the denominator in the model. The risk of finding an additional plague-positive animal increased as the call volume per census tract increased. The risk in the census tracts with >3 calls a month was significantly higher than that with three or less calls in a month. For tracts with 4-5 calls, the relative risk (RR) of an additional plague-positive carcass was 10.08 (95% CI 5.46-18.61); for tracts with 6-8 calls, the RR = 5.20 (2.93-9.20); for tracts with 9-11 calls, the RR = 12.80 (5.85-28.03) and tracts with >11 calls had RR = 35.41 (18.60-67.40). Overall, the call-in centre directed sampling increased the probability of locating plague-infected carcasses in the known Denver epizootic. Further studies are needed to determine the effectiveness of this methodology at monitoring large-scale zoonotic disease occurrence in the absence of a recognized epizootic.

  4. Current status and prospects of research on new plague vaccines%新型鼠疫疫苗研究现状及展望

    Institute of Scientific and Technical Information of China (English)

    焦磊

    2011-01-01

    As current available attenuated plague vaccine for human has some disadvantages in terms of product consistency, inoculating convenience, adverse reactions and protection against pneumonic plague,new plague vaccine research is promoted. In this review, potential candidate antigens for plague vaccines and immiunity against plague, as well as current status, obstacles and prospects of new plague vaccine research are discussed.%现行人用鼠疫活疫苗在产品的一致性、易操作性、不良反应以及对肺鼠疫的预防等方面均存在不足,这就促进了新型鼠疫疫苗的研究.此文从鼠疫疫苗潜在候选抗原、抗鼠疫免疫及新型鼠疫疫苗研究现状、障碍和展望等方面进行综述.

  5. Plague cycles in two rodent species from China: Dry years might provide context for epizootics in wet years

    Science.gov (United States)

    Eads, David; Biggins, Dean E.; Xu, Lei; Liu, Qiyong

    2016-01-01

    Plague, a rodent-associated, flea-borne zoonosis, is one of the most notorious diseases in history. Rates of plague transmission can increase when fleas are abundant. Fleas commonly desiccate and die when reared under dry conditions in laboratories, suggesting fleas will be suppressed during droughts in the wild, thus reducing the rate at which plague spreads among hosts. In contrast, fleas might increase in abundance when precipitation is plentiful, producing epizootic outbreaks during wet years. We tested these hypotheses using a 27-yr data set from two rodents in Inner Mongolia, China: Mongolian gerbils (Meriones unguiculatus) and Daurian ground squirrels (Spermophilus dauricus). For both species of rodents, fleas were most abundant during years preceded by dry growing seasons. For gerbils, the prevalence of plague increased during wet years preceded by dry growing seasons. If precipitation is scarce during the primary growing season, succulent plants decline in abundance and, consequently, herbivorous rodents can suffer declines in body condition. Fleas produce more offspring and better survive when parasitizing food-limited hosts, because starving animals tend to exhibit inefficient behavioral and immunological defenses against fleas. Further, rodent burrows might buffer fleas from xeric conditions aboveground during dry years. After a dry year, fleas might be abundant due to the preceding drought, and if precipitation and succulent plants become more plentiful, rodents could increase in density, thereby creating connectivity that facilitates the spread of plague. Moreover, in wet years, mild temperatures might increase the efficiency at which fleas transmit the plague bacterium, while also helping fleas to survive as they quest among hosts. In this way, dry years could provide context for epizootics of plague in wet years.

  6. The sex-selective impact of the Black Death and recurring plagues in the Southern Netherlands, 1349-1450.

    Science.gov (United States)

    Curtis, Daniel R; Roosen, Joris

    2017-06-15

    Although recent work has begun to establish that early modern plagues had selective mortality effects, it was generally accepted that the initial outbreak of Black Death in 1347-52 was a "universal killer." Recent bioarchaeological work, however, has argued that the Black Death was also selective with regard to age and pre-plague health status. The issue of the Black Death's potential sex selectivity is less clear. Bioarchaeological research hypothesizes that sex-selection in mortality was possible during the initial Black Death outbreak, and we present evidence from historical sources to test this notion. To determine whether the Black Death and recurring plagues in the period 1349-1450 had a sex-selective mortality effect. We present a newly compiled database of mortality information taken from mortmain records in Hainaut, Belgium, in the period 1349-1450, which not only is an important new source of information on medieval mortality, but also allows for sex-disaggregation. We find that the Black Death period of 1349-51, as well as recurring plagues in the 100 years up to 1450, often had a sex-selective effect-killing more women than in "non-plague years." Although much research tends to suggest that men are more susceptible to a variety of diseases caused by bacteria, viruses and parasites, we cannot assume that the same direction of sex-selection in mortality applied to diseases in the distant past such as Second Pandemic plagues. While the exact reasons for the sex-selective effect of late-medieval plague are unclear in the absence of further data, we suggest that simple inequities between the sexes in exposure to the disease may not have been a key driver. © 2017 Wiley Periodicals, Inc.

  7. Vector control improves survival of three species of prairie dogs (Cynomys) in areas considered enzootic for plague

    Science.gov (United States)

    Biggins, Dean E.; Godbey, Jerry L.; Gage, Kenneth L.; Carter, Leon G.; Montenieri, John A.

    2010-01-01

    Plague causes periodic epizootics that decimate populations of prairie dogs (PDs) (Cynomys), but the means by which the causative bacterium (Yersinia pestis) persists between epizootics are poorly understood. Plague epizootics in PDs might arise as the result of introductions of Y. pestis from sources outside PD colonies. However, it remains possible that plague persists in PDs during interepizootic periods and is transmitted at low rates among highly susceptible individuals within and between their colonies. If this is true, application of vector control to reduce flea numbers might reduce mortality among PDs. To test whether vector control enhances PD survival in the absence of obvious plague epizootics, we reduced the numbers of fleas (vectors for Y. pestis) 96–98% (1 month posttreatment) on 15 areas involving three species of PDs (Cynomys leucurus, Cynomys parvidens in Utah, and Cynomys ludovicianus in Montana) during 2000–2004 using deltamethrin dust delivered into burrows as a pulicide. Even during years without epizootic plague, PD survival rates at dusted sites were 31–45% higher for adults and 2–34% higher for juveniles compared to survival rates at nondusted sites. Y. pestis was cultured from 49 of the 851 flea pools tested (6882 total fleas) and antibodies against Y. pestis were identified in serum samples from 40 of 2631 PDs. Although other explanations are possible, including transmission of other potentially fatal pathogens by fleas, ticks, or other ectoparasites, our results suggest that plague might be maintained indefinitely in PD populations in the absence of free epizootics and widespread mortality among these animals. If PDs and their fleas support enzootic cycles of plague transmission, there would be important implications for the conservation of these animals and other species.

  8. Early-phase transmission of Yersinia pestis by unblocked fleas as a mechanism explaining rapidly spreading plague epizootics

    Science.gov (United States)

    Eisen, Rebecca J.; Bearden, Scott W.; Wilder, Aryn P.; Montenieri, John A.; Antolin, Michael F.; Gage, Kenneth L.

    2006-01-01

    Plague is a highly virulent disease believed to have killed millions during three historic human pandemics. Worldwide, it remains a threat to humans and is a potential agent of bioterrorism. Dissemination of Yersinia pestis, the etiological agent of plague, by blocked fleas has been the accepted paradigm for flea-borne transmission. However, this mechanism, which requires a lengthy extrinsic incubation period before a short infectious window often followed by death of the flea, cannot sufficiently explain the rapid rate of spread that typifies plague epidemics and epizootics. Inconsistencies between the expected rate of spread by blocked rat fleas and that observed during the Black Death has even caused speculation that plague was not the cause of this medieval pandemic. We used the primary vector to humans in North America, Oropsylla montana, which rarely becomes blocked, as a model for studying alternative flea-borne transmission mechanisms. Our data revealed that, in contrast to the classical blocked flea model, O. montana is immediately infectious, transmits efficiently for at least 4 d postinfection (early phase) and may remain infectious for a long time because the fleas do not suffer block-induced mortality. These factors match the criteria required to drive plague epizootics as defined by recently published mathematical models. The scenario of efficient early-phase transmission by unblocked fleas described in our study calls for a paradigm shift in concepts of how Y. pestis is transmitted during rapidly spreading epizootics and epidemics, including, perhaps, the Black Death. PMID:17032761

  9. Early-phase transmission of Yersinia pestis by unblocked fleas as a mechanism explaining rapidly spreading plague epizootics.

    Science.gov (United States)

    Eisen, Rebecca J; Bearden, Scott W; Wilder, Aryn P; Montenieri, John A; Antolin, Michael F; Gage, Kenneth L

    2006-10-17

    Plague is a highly virulent disease believed to have killed millions during three historic human pandemics. Worldwide, it remains a threat to humans and is a potential agent of bioterrorism. Dissemination of Yersinia pestis, the etiological agent of plague, by blocked fleas has been the accepted paradigm for flea-borne transmission. However, this mechanism, which requires a lengthy extrinsic incubation period before a short infectious window often followed by death of the flea, cannot sufficiently explain the rapid rate of spread that typifies plague epidemics and epizootics. Inconsistencies between the expected rate of spread by blocked rat fleas and that observed during the Black Death has even caused speculation that plague was not the cause of this medieval pandemic. We used the primary vector to humans in North America, Oropsylla montana, which rarely becomes blocked, as a model for studying alternative flea-borne transmission mechanisms. Our data revealed that, in contrast to the classical blocked flea model, O. montana is immediately infectious, transmits efficiently for at least 4 d postinfection (early phase) and may remain infectious for a long time because the fleas do not suffer block-induced mortality. These factors match the criteria required to drive plague epizootics as defined by recently published mathematical models. The scenario of efficient early-phase transmission by unblocked fleas described in our study calls for a paradigm shift in concepts of how Y. pestis is transmitted during rapidly spreading epizootics and epidemics, including, perhaps, the Black Death.

  10. Yersinia pestis biovar Microtus strain 201, an avirulent strain to humans, provides protection against bubonic plague in rhesus macaques.

    Science.gov (United States)

    Zhang, Qingwen; Wang, Qiong; Tian, Guang; Qi, Zhizhen; Zhang, Xuecan; Wu, Xiaohong; Qiu, Yefeng; Bi, Yujing; Yang, Xiaoyan; Xin, Youquan; He, Jian; Zhou, Jiyuan; Zeng, Lin; Yang, Ruifu; Wang, Xiaoyi

    2014-01-01

    Yersinia pestis biovar Microtus is considered to be a virulent to larger mammals, including guinea pigs, rabbits and humans. It may be used as live attenuated plague vaccine candidates in terms of its low virulence. However, the Microtus strain's protection against plague has yet to be demonstrated in larger mammals. In this study, we evaluated the protective efficacy of the Microtus strain 201 as a live attenuated plague vaccine candidate. Our results show that this strain is highly attenuated by subcutaneous route, elicits an F1-specific antibody titer similar to the EV and provides a protective efficacy similar to the EV against bubonic plague in Chinese-origin rhesus macaques. The Microtus strain 201 could induce elevated secretion of both Th1-associated cytokines (IFN-γ, IL-2 and TNF-α) and Th2-associated cytokines (IL-4, IL-5, and IL-6), as well as chemokines MCP-1 and IL-8. However, the protected animals developed skin ulcer at challenge site with different severity in most of the immunized and some of the EV-immunized monkeys. Generally, the Microtus strain 201 represented a good plague vaccine candidate based on its ability to generate strong humoral and cell-mediated immune responses as well as its good protection against high dose of subcutaneous virulent Y. pestis challenge.

  11. Diagnosis of Bubonic Plague by PCR in Madagascar under Field Conditions

    Science.gov (United States)

    Rahalison, L.; Vololonirina, E.; Ratsitorahina, M.; Chanteau, S.

    2000-01-01

    The diagnostic value of a PCR assay that amplifies a 501-bp fragment of the Yersinia pestis caf1 gene has been determined in a reference laboratory with 218 bubo aspirates collected from patients with clinically suspected plague managed in a regional hospital in Madagascar. The culture of Y. pestis and the detection of the F1 antigen (Ag) by enzyme-linked immunosorbent assay (ELISA) were used as reference diagnostic methods. The sensitivity of PCR was 89% (57 of 64) for the Y. pestis-positive patients, and 80.7% (63 of 78) for the F1 Ag-positive patients. The specificity of PCR for the culture-, F1 Ag-, and antibody-negative patients (n = 105) was 100%. Because in Madagascar most patients with plague are managed and their clinical samples are collected in remote villages, the usefulness of PCR was evaluated for routine diagnostic use in the operational conditions of the control program. The sensitivity of PCR was 50% (25 of 50) relative to the results of culture and 35.2% (19 of 54) relative to the results of the F1 Ag immunocapture ELISA. The specificity of PCR under these conditions was 96%. In conclusion, the PCR method was found to be very specific but not as sensitive as culture or the F1 Ag detection method. The limitation in sensitivity may have been due to suboptimal field conditions and the small volumes of samples used for DNA extraction. This technique is not recommended as a routine diagnostic test for plague in Madagascar. PMID:10618097

  12. PRECIPITATION, CLIMATE CHANGE, AND PARASITISM OF PRAIRIE DOGS BY FLEAS THAT TRANSMIT PLAGUE.

    Science.gov (United States)

    Eads, David; Hoogland, John

    2017-03-30

    Fleas (Insecta: Siphonaptera) are hematophagous ectoparasites that can reduce the fitness of vertebrate hosts. Laboratory populations of fleas decline under dry conditions, implying that populations of fleas will also decline when precipitation is scarce under natural conditions. If precipitation and hence vegetative production are reduced, however, then herbivorous hosts might suffer declines in body condition and have weakened defenses against fleas, so that fleas will increase in abundance. We tested these competing hypotheses using information from 23 yr of research on 3 species of colonial prairie dogs in western USA: Gunnison's prairie dogs (Cynomys gunnisoni, 1989-1994), Utah prairie dogs (C. parvidens, 1996-2005), and white-tailed prairie dogs (C. leucurus, 2006-2012). For all 3 species, flea-counts per individual varied inversely with the number of days in the prior growing season with >10 mm of precipitation, an index of the number of precipitation events that might have caused a substantial, prolonged increase in soil moisture and vegetative production. Flea-counts per Utah prairie dog also varied inversely with cumulative precipitation of the prior growing season. Further, flea-counts per Gunnison's and white-tailed prairie dog varied inversely with cumulative precipitation of the just-completed January and February. These results complement research on black-tailed prairie dogs (C. ludovicianus) and might have important ramifications for plague, a bacterial disease, transmitted by fleas, that devastates populations of prairie dogs. In particular, our results might help to explain why, at some colonies, epizootics of plague, which can kill >95% of prairie dogs, are more likely to occur during or shortly after periods of reduced precipitation. Climate change is projected to increase the frequency of droughts in the grasslands of western North America. If so, then climate change might affect the occurrence of plague epizootics among prairie dogs and other

  13. Temporal phylogeography of Yersinia pestis in Madagascar: Insights into the long-term maintenance of plague.

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    Amy J Vogler

    2017-09-01

    Full Text Available Yersinia pestis appears to be maintained in multiple, geographically separate, and phylogenetically distinct subpopulations within the highlands of Madagascar. However, the dynamics of these locally differentiated subpopulations through time are mostly unknown. To address that gap and further inform our understanding of plague epidemiology, we investigated the phylogeography of Y. pestis in Madagascar over an 18 year period.We generated whole genome sequences for 31 strains and discovered new SNPs that we used in conjunction with previously identified SNPs and variable-number tandem repeats (VNTRs to genotype 773 Malagasy Y. pestis samples from 1995 to 2012. We mapped the locations where samples were obtained on a fine geographic scale to examine phylogeographic patterns through time. We identified 18 geographically separate and phylogenetically distinct subpopulations that display spatial and temporal stability, persisting in the same locations over a period of almost two decades. We found that geographic areas with higher levels of topographical relief are associated with greater levels of phylogenetic diversity and that sampling frequency can vary considerably among subpopulations and from year to year. We also found evidence of various Y. pestis dispersal events, including over long distances, but no evidence that any dispersal events resulted in successful establishment of a transferred genotype in a new location during the examined time period.Our analysis suggests that persistent endemic cycles of Y. pestis transmission within local areas are responsible for the long term maintenance of plague in Madagascar, rather than repeated episodes of wide scale epidemic spread. Landscape likely plays a role in maintaining Y. pestis subpopulations in Madagascar, with increased topographical relief associated with increased levels of localized differentiation. Local ecological factors likely affect the dynamics of individual subpopulations and the

  14. Temporal phylogeography of Yersinia pestis in Madagascar: Insights into the long-term maintenance of plague.

    Science.gov (United States)

    Vogler, Amy J; Andrianaivoarimanana, Voahangy; Telfer, Sandra; Hall, Carina M; Sahl, Jason W; Hepp, Crystal M; Centner, Heather; Andersen, Genevieve; Birdsell, Dawn N; Rahalison, Lila; Nottingham, Roxanne; Keim, Paul; Wagner, David M; Rajerison, Minoarisoa

    2017-09-01

    Yersinia pestis appears to be maintained in multiple, geographically separate, and phylogenetically distinct subpopulations within the highlands of Madagascar. However, the dynamics of these locally differentiated subpopulations through time are mostly unknown. To address that gap and further inform our understanding of plague epidemiology, we investigated the phylogeography of Y. pestis in Madagascar over an 18 year period. We generated whole genome sequences for 31 strains and discovered new SNPs that we used in conjunction with previously identified SNPs and variable-number tandem repeats (VNTRs) to genotype 773 Malagasy Y. pestis samples from 1995 to 2012. We mapped the locations where samples were obtained on a fine geographic scale to examine phylogeographic patterns through time. We identified 18 geographically separate and phylogenetically distinct subpopulations that display spatial and temporal stability, persisting in the same locations over a period of almost two decades. We found that geographic areas with higher levels of topographical relief are associated with greater levels of phylogenetic diversity and that sampling frequency can vary considerably among subpopulations and from year to year. We also found evidence of various Y. pestis dispersal events, including over long distances, but no evidence that any dispersal events resulted in successful establishment of a transferred genotype in a new location during the examined time period. Our analysis suggests that persistent endemic cycles of Y. pestis transmission within local areas are responsible for the long term maintenance of plague in Madagascar, rather than repeated episodes of wide scale epidemic spread. Landscape likely plays a role in maintaining Y. pestis subpopulations in Madagascar, with increased topographical relief associated with increased levels of localized differentiation. Local ecological factors likely affect the dynamics of individual subpopulations and the associated

  15. Fast and Simple Detection of Yersinia pestis Applicable to Field Investigation of Plague Foci

    Science.gov (United States)

    Simon, Stéphanie; Demeure, Christian; Lamourette, Patricia; Filali, Sofia; Plaisance, Marc; Créminon, Christophe; Volland, Hervé; Carniel, Elisabeth

    2013-01-01

    Yersinia pestis, the plague bacillus, has a rodent-flea-rodent life cycle but can also persist in the environment for various periods of time. There is now a convenient and effective test (F1-dipstick) for the rapid identification of Y. pestis from human patient or rodent samples, but this test cannot be applied to environmental or flea materials because the F1 capsule is mostly produced at 37°C. The plasminogen activator (PLA), a key virulence factor encoded by a Y. pestis-specific plasmid, is synthesized both at 20°C and 37°C, making it a good candidate antigen for environmental detection of Y. pestis by immunological methods. A recombinant PLA protein from Y. pestis synthesized by an Escherichia coli strain was used to produce monoclonal antibodies (mAbs). PLA-specific mAbs devoid of cross-reactions with other homologous proteins were further cloned. A pair of mAbs was selected based on its specificity, sensitivity, comprehensiveness, and ability to react with Y. pestis strains grown at different temperatures. These antibodies were used to develop a highly sensitive one-step PLA-enzyme immunoassay (PLA-EIA) and an immunostrip (PLA-dipstick), usable as a rapid test under field conditions. These two PLA-immunometric tests could be valuable, in addition to the F1-disptick, to confirm human plague diagnosis in non-endemic areas (WHO standard case definition). They have the supplementary advantage of allowing a rapid and easy detection of Y. pestis in environmental and flea samples, and would therefore be of great value for surveillance and epidemiological investigations of plague foci. Finally, they will be able to detect natural or genetically engineered F1-negative Y. pestis strains in human patients and environmental samples. PMID:23383008

  16. Fast and simple detection of Yersinia pestis applicable to field investigation of plague foci.

    Directory of Open Access Journals (Sweden)

    Stéphanie Simon

    Full Text Available Yersinia pestis, the plague bacillus, has a rodent-flea-rodent life cycle but can also persist in the environment for various periods of time. There is now a convenient and effective test (F1-dipstick for the rapid identification of Y. pestis from human patient or rodent samples, but this test cannot be applied to environmental or flea materials because the F1 capsule is mostly produced at 37°C. The plasminogen activator (PLA, a key virulence factor encoded by a Y. pestis-specific plasmid, is synthesized both at 20°C and 37°C, making it a good candidate antigen for environmental detection of Y. pestis by immunological methods. A recombinant PLA protein from Y. pestis synthesized by an Escherichia coli strain was used to produce monoclonal antibodies (mAbs. PLA-specific mAbs devoid of cross-reactions with other homologous proteins were further cloned. A pair of mAbs was selected based on its specificity, sensitivity, comprehensiveness, and ability to react with Y. pestis strains grown at different temperatures. These antibodies were used to develop a highly sensitive one-step PLA-enzyme immunoassay (PLA-EIA and an immunostrip (PLA-dipstick, usable as a rapid test under field conditions. These two PLA-immunometric tests could be valuable, in addition to the F1-disptick, to confirm human plague diagnosis in non-endemic areas (WHO standard case definition. They have the supplementary advantage of allowing a rapid and easy detection of Y. pestis in environmental and flea samples, and would therefore be of great value for surveillance and epidemiological investigations of plague foci. Finally, they will be able to detect natural or genetically engineered F1-negative Y. pestis strains in human patients and environmental samples.

  17. Early modern "citation index"? Medical authorities in academic treatises on plague (1480-1725).

    Science.gov (United States)

    Cerný, K

    2012-01-01

    The paper deals with the problem of early modern scientific citations. It attempts to establish a measure of scientific popularity in a specific area of the academic medicine in a way which resembles a modern evaluation of scientific activity (citation index). For this purpose an analysis of a series of plague treatises written between 1480 and 1725 in Europe was conducted. Citations for various historical medical authorities (Hippocrates, Galen, etc.) are given in Tables which reflect a long time development of popularity. The authorities from various groups (Ancient, Medieval, Arabic, Early Modern) are linked together, and "generic authorities" are explained and discussed.

  18. [Plague in Algeria: about five strains of Yersinia pestis isolated during the outbreak of June 2003].

    Science.gov (United States)

    Lounici, M; Lazri, M; Rahal, K

    2005-02-01

    In this study, we isolated and identified five strains of Yersinia pestis during an epidemic occurred in west of Algeria in June 2003. The bacteriological identification was confirmed by bacteriophage susceptibility. All these strains belonged to the biovar Orientalis (they did not ferment glycerol but did reduce nitrate to nitrite) which caused the current pandemic. The in vitro activities of antimicrobial agents used to treat plague and recommended for prophylaxis, showed that they are active against all strains. The comparison of these strains by plasmid profile analyse demonstrated that all isolates had three plasmids: 110, 70 and 9.5 kb, which are present in Y. pestis strains.

  19. THE BUBONIC PLAGUE OF 1349, THE WAGE-TO-RENT RATIO, AND THE ENGLISH PEASANT FAMILY

    Directory of Open Access Journals (Sweden)

    Stephanie O. Crofton

    2005-01-01

    Full Text Available The bubonic plague that swept England in 1349 provides an example of how changes in economic conditions can change norms of social behavior. The death of almost 50 percent of the population altered the returns to labor and land. As the demand for land and the supply of labor declined, rents fell and wages rose. This increased wage-to-rent ratio shifted the structure of the economy from household production to market production. In turn, these changes affected migration, family and community ties, women s labor force participation, family size, inheritance customs, the status of landowning widows, and care for the elderly.

  20. Use of Insecticide Delivery Tubes for Controlling Rodent-Associated Fleas in a Plague Endemic Region of West Nile, Uganda.

    Science.gov (United States)

    Boegler, Karen A; Atiku, Linda A; Mpanga, Joseph Tendo; Clark, Rebecca J; Delorey, Mark J; Gage, Kenneth L; Eisen, Rebecca J

    2014-11-01

    Plague is a primarily flea-borne rodent-associated zoonosis that is often fatal in humans. Our study focused on the plague-endemic West Nile region of Uganda where affordable means for the prevention of human plague are currently lacking. Traditional hut construction and food storage practices hinder rodent exclusion efforts, and emphasize the need for an inexpensive but effective host-targeted approach for controlling fleas within the domestic environment. Here we demonstrate the ability of an insecticide delivery tube that is made from inexpensive locally available materials to reduce fleas on domestic rodents. Unbaited tubes were treated with either an insecticide alone (fipronil) or in conjunction with an insect growth regulator [(S)-methoprene], and placed along natural rodent runways within participant huts. Performance was similar for both treatments throughout the course of the study, and showed significant reductions in the proportion of infested rodents relative to controls for at least 100 d posttreatment.

  1. Prevalence and abundance of fleas in black-tailed prairie dog burrows: implications for the transmission of plague (Yersinia pestis).

    Science.gov (United States)

    Salkeld, Dan J; Stapp, Paul

    2008-06-01

    Plague, the disease caused by the bacterium Yersinia pestis, can have devastating impacts on North American wildlife. Epizootics, or die-offs, in prairie dogs (Cynomys ludovicianus) occur sporadically and fleas (Siphonaptera) are probably important in the disease's transmission and possibly as maintenance hosts of Y. pestis between epizootics. We monitored changes in flea abundance in prairie dog burrows in response to precipitation, temperature, and plague activity in shortgrass steppe in northern Colorado. Oropsylla hirsuta was the most commonly found flea, and it increased in abundance with temperature. In contrast, Oropsylla tuberculata cynomuris declined with rising temperature. During plague epizootics, flea abundance in burrows increased and then subsequently declined after the extirpation of their prairie dog hosts.

  2. Role of the Yersinia pestis plasminogen activator in the incidence of distinct septicemic and bubonic forms of flea-borne plague.

    Science.gov (United States)

    Sebbane, Florent; Jarrett, Clayton O; Gardner, Donald; Long, Daniel; Hinnebusch, B Joseph

    2006-04-04

    Yersinia pestis is transmitted by fleas and causes bubonic plague, characterized by severe local lymphadenitis that progresses rapidly to systemic infection and life-threatening septicemia. Here, we show that although flea-borne transmission usually leads to bubonic plague in mice, it can also lead to primary septicemic plague. However, intradermal injection of Y. pestis, commonly used to mimic transmission by fleabite, leads only to bubonic plague. A Y. pestis strain lacking the plasmid-encoded cell-surface plasminogen activator, which is avirulent by intradermal or s.c. injection, was able to cause fatal primary septicemic plague at low incidence, but not bubonic plague, when transmitted by fleas. The results clarify a long-standing uncertainty about the etiology of primary septicemic plague and support an evolutionary scenario in which plague first emerged as a flea-borne septicemic disease of limited transmissibility. Subsequent acquisition of the plasminogen activator gene by horizontal transfer enabled the bubonic form of disease and increased the potential for epidemic spread.

  3. CpG oligodeoxynucleotides augment the murine immune response to the Yersinia pestis F1-V vaccine in bubonic and pneumonic models of plague.

    Science.gov (United States)

    Amemiya, Kei; Meyers, Jennifer L; Rogers, Taralyn E; Fast, Randy L; Bassett, Anthony D; Worsham, Patricia L; Powell, Bradford S; Norris, Sarah L; Krieg, Arthur M; Adamovicz, Jeffrey J

    2009-04-06

    The current U.S. Department of Defense candidate plague vaccine is a fusion between two Yersinia pestis proteins: the F1 capsular protein, and the low calcium response (Lcr) V-protein. We hypothesized that an immunomodulator, such as CpG oligodeoxynucleotide (ODN)s, could augment the immune response to the plague F1-V vaccine in a mouse model for plague. CpG ODNs significantly augmented the antibody response and efficacy of a single dose of the plague vaccine in murine bubonic and pneumonic models of plague. In the latter study, we also found an overall significant augmentation the immune response to the individual subunits of the plague vaccine by CpG ODN 2006. In a long-term, prime-boost study, CpG ODN induced a significant early augmentation of the IgG response to the vaccine. The presence of CpG ODN induced a significant increase in the IgG2a subclass response to the vaccine up to 5 months after the boost. Our studies showed that CpG ODNs significantly augmented the IgG antibody response to the plague vaccine, which increased the probability of survival in murine models of plague (P<0.0001).

  4. Treatment of black-tailed prairie dog burrows with deltamethrin to control fleas (Insecta: Siphonaptera) and plague.

    Science.gov (United States)

    Seery, David B; Biggins, Dean E; Montenieri, John A; Enscore, Russell E; Tanda, Dale T; Gage, Kenneth L

    2003-09-01

    Burrows within black-tailed prairie dog (Cynomys ludovicianus) colonies on the Rocky Mountain Arsenal National Wildlife Refuge, Colorado, were dusted with deltamethrin insecticide to reduce flea (Insecta: Siphonaptera) abundance. Flea populations were monitored pre- and posttreatment by combing prairie dogs and collecting fleas from burrows. A single application of deltamethrin significantly reduced populations of the plague vector Oropsylla hirsuta, and other flea species on prairie dogs and in prairie dog burrows for at least 84 d. A plague epizootic on the Rocky Mountain Arsenal National Wildlife Refuge caused high mortality of prairie dogs on some untreated colonies, but did not appear to affect nearby colonies dusted with deltamethrin.

  5. Emergence, spread, persistence and fade-out of sylvatic plague in Kazakhstan.

    Science.gov (United States)

    Heier, Lise; Storvik, Geir O; Davis, Stephen A; Viljugrein, Hildegunn; Ageyev, Vladimir S; Klassovskaya, Evgeniya; Stenseth, Nils Chr

    2011-10-01

    Predicting the dynamics of zoonoses in wildlife is important not only for prevention of transmission to humans, but also for improving the general understanding of epidemiological processes. A large dataset on sylvatic plague in the Pre-Balkhash area of Kazakhstan (collected for surveillance purposes) provides a rare opportunity for detailed statistical modelling of an infectious disease. Previous work using these data has revealed a host abundance threshold for epizootics, and climatic influences on plague prevalence. Here, we present a model describing the local space-time dynamics of the disease at a spatial scale of 20 × 20 km(2) and a biannual temporal scale, distinguishing between invasion and persistence events. We used a Bayesian imputation method to account for uncertainties resulting from poor data in explanatory variables and response variables. Spatial autocorrelation in the data was accounted for in imputations and analyses through random effects. The results show (i) a clear effect of spatial transmission, (ii) a high probability of persistence compared with invasion, and (iii) a stronger influence of rodent abundance on invasion than on persistence. In particular, there was a substantial probability of persistence also at low host abundance.

  6. Practical disinfection chemicals for fishing and crayfishing gear against crayfish plague transfer

    Directory of Open Access Journals (Sweden)

    Jussila J.

    2014-01-01

    Full Text Available We tested four commercial disinfectants against crayfish plague (Aphanomyces astaci spores in both aquatic solutions and with material mimicking fishing and crayfishing gear, e.g. traps, ropes, mesh, etc. The tested disinfectants were Proxitane®5:14, Proxitane®12:20, Wofasteril®E400, Virkon®S and hydrogen peroxide. The effects of the chemicals were initially tested in liquid zoospore cultures and the effective concentrations were then further tested using clean and dirty model materials (PP sheet, nylon rope, cotton fabric contaminated with A. astaci spore solutions. The disinfectants effective against infective crayfish plague spores with both clean and dirty model materials were Proxinate®5:14 (effective concentration was 30 mg·L-1 of PAA and Virkon®S (3 g·L-1, while Proxinate®12:20 (10 mg·L-1 of PAA and Wofasteril®E400 (30 mg·L-1 of PAA worked only with clean model materials. Hydrogen peroxide was not effective in the tested concentrations and conditions. Based on the results, the disinfectants most suitable for the fishing and crayfishing gear disinfection would be Proxitane®5:14 and Virkon®S, with the condition that all the gear should be thoroughly cleaned of organic matter to ensure inactivation of A. astaci spores.

  7. Oral vaccination against bubonic plague using a live avirulent Yersinia pseudotuberculosis strain.

    Science.gov (United States)

    Blisnick, Thierry; Ave, Patrick; Huerre, Michel; Carniel, Elisabeth; Demeure, Christian E

    2008-08-01

    We evaluated the possibility of using Yersinia pseudotuberculosis as a live vaccine against plague because it shares high genetic identity with Y. pestis while being much less virulent, genetically much more stable, and deliverable orally. A total of 41 Y. pseudotuberculosis strains were screened by PCR for the absence of the high pathogenicity island, the superantigens YPM, and the type IV pilus and the presence of the pYV virulence plasmid. One strain (IP32680) fulfilled these criteria. This strain was avirulent in mice upon intragastric or subcutaneous inoculation and persisted for 2 months in the mouse intestine without clinical signs of disease. IP32680 reached the mesenteric lymph nodes, spleen, and liver without causing major histological lesions and was cleared after 13 days. The antibodies produced in vaccinated animals recognized both Y. pseudotuberculosis and Y. pestis antigens efficiently. After a subcutaneous challenge with Y. pestis CO92, bacteria were found in low amounts in the organs and rarely in the blood of vaccinated animals. One oral IP32680 inoculation protected 75% of the mice, and two inoculations induced much higher antibody titers and protected 88% of the mice. Our results thus validate the concept that an attenuated Y. pseudotuberculosis strain can be an efficient, inexpensive, safe, and easy-to-produce live vaccine for oral immunization against bubonic plague.

  8. Comparison of Models for Bubonic Plague Reveals Unique Pathogen Adaptations to the Dermis.

    Science.gov (United States)

    Gonzalez, Rodrigo J; Weening, Eric H; Lane, M Chelsea; Miller, Virginia L

    2015-07-01

    Vector-borne pathogens are inoculated in the skin of mammals, most likely in the dermis. Despite this, subcutaneous (s.c.) models of infection are broadly used in many fields, including Yersinia pestis pathogenesis. We expand on a previous report where we implemented intradermal (i.d.) inoculations to study bacterial dissemination during bubonic plague and compare this model with an s.c. We found that i.d. inoculations result in faster kinetics of infection and that bacterial dose influenced mouse survival after i.d. but not s.c. inoculation. Moreover, a deletion mutant of rovA, previously shown to be moderately attenuated in the s.c. model, was severely attenuated in the i.d. Lastly, based on previous observations where a population bottleneck from the skin to lymph nodes was observed after i.d., but not after s.c., inoculations, we used the latter model as a strategy to identify an additional bottleneck in bacterial dissemination from lymph nodes to the bloodstream. Our data indicate that the more biologically relevant i.d. model of bubonic plague differs significantly from the s.c. model in multiple aspects of infection. These findings reveal adaptations of Y. pestis to the dermis and how these adaptations can define the progression of disease. They also emphasize the importance of using a relevant route of infection when addressing host-pathogen interactions. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  9. Modelling the black death. A historical case study and implications for the epidemiology of bubonic plague.

    Science.gov (United States)

    Monecke, Stefan; Monecke, Hannelore; Monecke, Jochen

    2009-12-01

    We analysed a plague outbreak in the mining town of Freiberg in Saxony which started in May 1613 and ended in February 1614. This epidemic was selected for study because of the high quality of contemporary sources. It was possible to identify 1400 individual victims meaning that more than 10% of the population of the city perished. The outbreak was modelled by 9 differential equations describing flea, rat, and human populations. This resulted in a close fit to the historical records of this outbreak. An interesting implication of the model is that the introduction of even a small number of immune rats into an otherwise unchanged setting results in an abortive outbreak with very few human victims. Hence, the percentage of immune rats directly influences the magnitude of a human epidemic by diverting search activities of the fleas. Thus, we conclude that the spread of Rattus norvegicus, which might acquire partial herd immunity by exposure to soil- or water-borne Yersinia species due to its preference for wet habitats, contributed to the disappearance of Black Death epidemics from Europe in the 18th century. In order to prove whether or not the parameter values obtained by fitting a given outbreak are also applicable to other cases, we modelled the plague outbreak in Bombay 1905/06 using the same parameter values except for the number of humans as well as of immune and susceptible rats.

  10. Glutathionylation of Yersinia pestis LcrV and Its Effects on Plague Pathogenesis

    Directory of Open Access Journals (Sweden)

    Anthony Mitchell

    2017-05-01

    Full Text Available Glutathionylation, the formation of reversible mixed disulfides between glutathione and protein cysteine residues, is a posttranslational modification previously observed for intracellular proteins of bacteria. Here we show that Yersinia pestis LcrV, a secreted protein capping the type III secretion machine, is glutathionylated at Cys273 and that this modification promotes association with host ribosomal protein S3 (RPS3, moderates Y. pestis type III effector transport and killing of macrophages, and enhances bubonic plague pathogenesis in mice and rats. Secreted LcrV was purified and analyzed by mass spectrometry to reveal glutathionylation, a modification that is abolished by the codon substitution Cys273Ala in lcrV. Moreover, the lcrVC273A mutation enhanced the survival of animals in models of bubonic plague. Investigating the molecular mechanism responsible for these virulence attributes, we identified macrophage RPS3 as a ligand of LcrV, an association that is perturbed by the Cys273Ala substitution. Furthermore, macrophages infected by the lcrVC273A variant displayed accelerated apoptotic death and diminished proinflammatory cytokine release. Deletion of gshB, which encodes glutathione synthetase of Y. pestis, resulted in undetectable levels of intracellular glutathione, and we used a Y. pestis ΔgshB mutant to characterize the biochemical pathway of LcrV glutathionylation, establishing that LcrV is modified after its transport to the type III needle via disulfide bond formation with extracellular oxidized glutathione.

  11. Adaptive response of Yersinia pestis to extracellular effectors of innate immunity during bubonic plague.

    Science.gov (United States)

    Sebbane, Florent; Lemaître, Nadine; Sturdevant, Daniel E; Rebeil, Roberto; Virtaneva, Kimmo; Porcella, Stephen F; Hinnebusch, B Joseph

    2006-08-01

    Yersinia pestis causes bubonic plague, characterized by an enlarged, painful lymph node, termed a bubo, that develops after bacterial dissemination from a fleabite site. In susceptible animals, the bacteria rapidly escape containment in the lymph node, spread systemically through the blood, and produce fatal sepsis. The fulminant progression of disease has been largely ascribed to the ability of Y. pestis to avoid phagocytosis and exposure to antimicrobial effectors of innate immunity. In vivo microarray analysis of Y. pestis gene expression, however, revealed an adaptive response to nitric oxide (NO)-derived reactive nitrogen species and to iron limitation in the extracellular environment of the bubo. Polymorphonuclear neutrophils recruited to the infected lymph node expressed abundant inducible NO synthase, and several Y. pestis homologs of genes involved in the protective response to reactive nitrogen species were up-regulated in the bubo. Mutation of one of these genes, which encodes the Hmp flavohemoglobin that detoxifies NO, attenuated virulence. Thus, the ability of Y. pestis to destroy immune cells and remain extracellular in the bubo appears to limit exposure to some but not all innate immune effectors. High NO levels induced during plague may also influence the developing adaptive immune response and contribute to septic shock.

  12. Yersinia pestis Yop secretion protein F: purification, characterization, and protective efficacy against bubonic plague.

    Science.gov (United States)

    Swietnicki, Wieslaw; Powell, Bradford S; Goodin, Jeremy

    2005-07-01

    Yersinia pestis is a gram-negative human pathogen that uses a type III secretion system to deliver virulence factors into human hosts. The delivery is contact-dependent and it has been proposed that polymerization of Yop secretion protein F (YscF) is used to puncture mammalian cell membranes to facilitate delivery of Yersinia outer protein effectors into host cells. To evaluate the potential immunogenicity and protective efficacy of YscF against Y. pestis, we used a purified recombinant YscF protein as a potential vaccine candidate in a mouse subcutaneous infection model. YscF was expressed and purified from Escherichia coli by immobilized metal-ion affinity chromatography and protein identity was confirmed by ion trap mass spectrometry. The recombinant protein was highly alpha-helical and formed relatively stable aggregates under physiological conditions. The properties were consistent with behavior expected for the native YscF, suggesting that the antigen was properly folded. Ten mice were inoculated subcutaneously, administered booster injections after one month, and challenged with 130 LD(50) of wild type Y. pestis CO92. Six animals in the vaccinated group but none in the control group survived the challenge. The vaccinated animals produced high levels of specific antibodies against YscF as determined by Western blot. The data were statistically significant (P = 0.053 by two-tailed Fisher's test), suggesting that the YscF protein can provide a protective immune response against lethal plague challenge during subcutaneous plague infection.

  13. O Carnaval, a peste e a 'espanhola' Carnival, the plague, and the Spanish flu

    Directory of Open Access Journals (Sweden)

    Ricardo Augusto dos Santos

    2006-03-01

    Full Text Available Este texto apresenta algumas imagens (fotografias, pinturas relativas às epidemias de Peste e Gripe Espanhola. Procuramos demonstrar como fenômenos históricos analisados comparativamente revelam semelhanças em distintas formações sociais. Apesar das diferenças de tempo e espaço, existem manifestações simbólicas coletivas invariáveis nas epidemias. Por exemplo, em várias ocorrências de peste, gripe ou cólera, a associação entre doença e castigo divino está presente. De forma análoga, indivíduos de comportamento "suspeito" foram e são apontados como propagadores das enfermidades, sejam pobres, judeus, irlandeses ou negros.The article presents photographic and painted images related to epidemics of the plague and Spanish flu. Comparative analyses of this type of historical phenomena reveal similarities between diverse social formations. Despite differences in time and space, epidemics display certain invariable symbolic collective expressions. For example, disease and divine punishment have been linked during a number of plague, flu, or cholera epidemics. Similarly, individuals whose behavior is 'suspicious' have been accused of spreading illness - for instance, the poor, Jews, Irish, or blacks.

  14. The Venetian lazarettos of Candia and the Great Plague (1592 - 1595).

    Science.gov (United States)

    Tsiamis, Costas; Thalassinou, Eleni; Poulakou-Rebelakou, Effie; Tsakris, Athanasios; Hatzakis, Angelos

    2014-03-01

    The present study highlights the history of lazarettos in Candia (modern Heraklion, Crete, Greece), which was the most important Venetian possession in the Mediterranean at the time, while at the same time it recounts the terrible plague which went down in history as the Great Plague of Candia (1592-1595). The study will also attempt to give a satisfactory answer to the epidemiological questions raised by the worst epidemic that Crete had experienced since the era of the Black Death in the 14th century. The city was about to lose more than a half of its population (51.3%), although it was saved from complete annihilation by the composure, courage and inventiveness of its Venetian commander, Filippo Pasqualigo, whose report to the Venetian Senate makes an invaluable source of information regarding the events of this dramatic period. Candia would also witness the emergence of typical human reactions in cases of epidemics and mass deaths, such as running away along with the feeling of self-preservation, dissolute life and ephemeral pleasures, as well as lawlessness and criminality. The lazaretto proved inefficient in the face of a disaster of such scale, whereas the epidemic functioned as a "crash-test" for the Venetian health system. Eventually, in an era when the microbial nature of the disease was unknown, it seems that it was practically impossible to handle emergency situations of large-scale epidemics successfully, despite strict laws and well-organized precautionary health systems.

  15. Phylogenetic Analysis of Entomoparasitic Nematodes, Potential Control Agents of Flea Populations in Natural Foci of Plague

    Science.gov (United States)

    Koshel, E. I.; Aleshin, V. V.; Eroshenko, G. A.; Kutyrev, V. V.

    2014-01-01

    Entomoparasitic nematodes are natural control agents for many insect pests, including fleas that transmit Yersinia pestis, a causative agent of plague, in the natural foci of this extremely dangerous zoonosis. We examined the flea samples from the Volga-Ural natural focus of plague for their infestation with nematodes. Among the six flea species feeding on different rodent hosts (Citellus pygmaeus, Microtus socialis, and Allactaga major), the rate of infestation varied from 0 to 21%. The propagation rate of parasitic nematodes in the haemocoel of infected fleas was very high; in some cases, we observed up to 1,000 juveniles per flea specimen. Our study of morphology, life cycle, and rDNA sequences of these parasites revealed that they belong to three distinct species differing in the host specificity. On SSU and LSU rRNA phylogenies, these species representing three genera (Rubzovinema, Psyllotylenchus, and Spilotylenchus), constitute a monophyletic group close to Allantonema and Parasitylenchus, the type genera of the families Allantonematidae and Parasitylenchidae (Nematoda: Tylenchida). We discuss the SSU-ITS1-5.8S-LSU rDNA phylogeny of the Tylenchida with a special emphasis on the suborder Hexatylina. PMID:24804197

  16. Emergence, spread, persistence and fade-out of sylvatic plague in Kazakhstan

    Science.gov (United States)

    Heier, Lise; Storvik, Geir O.; Davis, Stephen A.; Viljugrein, Hildegunn; Ageyev, Vladimir S.; Klassovskaya, Evgeniya; Stenseth, Nils Chr.

    2011-01-01

    Predicting the dynamics of zoonoses in wildlife is important not only for prevention of transmission to humans, but also for improving the general understanding of epidemiological processes. A large dataset on sylvatic plague in the Pre-Balkhash area of Kazakhstan (collected for surveillance purposes) provides a rare opportunity for detailed statistical modelling of an infectious disease. Previous work using these data has revealed a host abundance threshold for epizootics, and climatic influences on plague prevalence. Here, we present a model describing the local space–time dynamics of the disease at a spatial scale of 20 × 20 km2 and a biannual temporal scale, distinguishing between invasion and persistence events. We used a Bayesian imputation method to account for uncertainties resulting from poor data in explanatory variables and response variables. Spatial autocorrelation in the data was accounted for in imputations and analyses through random effects. The results show (i) a clear effect of spatial transmission, (ii) a high probability of persistence compared with invasion, and (iii) a stronger influence of rodent abundance on invasion than on persistence. In particular, there was a substantial probability of persistence also at low host abundance. PMID:21345866

  17. Molecular, serological and epidemiological observations after a suspected outbreak of plague in Nyimba, eastern Zambia.

    Science.gov (United States)

    Nyirenda, Stanley S; Hang'ombe, Bernard M; Kilonzo, Bukheti S; Kabeta, Mathews N; Cornellius, Mundia; Sinkala, Yona

    2017-01-01

    Plague is a re-emerging zoonotic disease caused by the bacterium Yersinia pestis. The disease has caused periodic global devastation since the first outbreak in the 6th century. Two months after a suspected plague outbreak in Nyimba district, samples were collected from 94 livestock (goats and pigs), 25 rodents, 6 shrews and 33 fleas. Enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR) techniques were used to investigate the presence of Y. pestis, which showed that 16.0% (4/25) of rodents, 16.7% (1/6) of shrews (Crocidura spp) and 6.0% (5/83) of goats were positive for IgG antibodies against Fraction 1 antigen of Y. pestis. Plasminogen activator (Pla) gene (DNA) of Y. pestis was detected in five pools containing 36.4% (12/33) fleas collected from pigs (n = 4), goats (n = 5) and rodents (n = 3). The detection of Pla gene in fleas and IgG antibodies against Fraction1 antigen in rodents, shrews and goats suggest that Y. pestis had been present in the study area in the recent past. © The Author(s) 2016.

  18. [ON THE ORIGIN OF HYPERVIRULENCE OF THE CAUSATIVE AGENT OF PLAGUE].

    Science.gov (United States)

    Anisimov, N V; Kislichkina, A A; Platonov, M E; Evseeva, V V; Kadnikova, L A; Lipatnikova, N A; Bogun, A G; Dentovskaya, S V; Anisimov, A P

    2016-01-01

    The attempt to combine Yersinia pseudotuberculosis and Yersinia pestis into one species has been unsupported by microbiologists due to the specific features of the epidemiology and clinical presentations of their induced diseases and to basic differences in their virulence. Pseudotuberculosis is predominantly a relatively mild human intestinal infection transmitted through contaminated food and plague is an acute generalized disease with high mortality, which is most frequently transmitted by the bites of infected fleas. Y. pestis hypervirulence, the ability of single bacteria to ensure the development of predagonal bacteriemia in rodents, which is sufficient to contaminate the fleas, is one of the main events during pathogen adaptation to a new ecological niche. By analyzing the data of molecular typing of the representative kits of naturally occurring Y. pestis isolates, the authois consider the issues of formation of intraspecies groups with universal hypervirulence, as well as biovars that are highly virulent only to their major host. A strategy for searching for selective virulence factors, the potential molecular targets for vaccination and etiotropic treatment of plague, is discussed.

  19. [Effect of immune modulation on immunogenic and protective activity of a live plague vaccine].

    Science.gov (United States)

    Karal'nik, B V; Ponomareva, T S; Deriabin, P N; Denisova, T G; Mel'nikova, N N; Tugambaev, T I; Atshabar, B B; Zakarian, S B

    2014-01-01

    Comparative evaluation of the effect of polyoxidonium and betaleukin on immunogenic and protective activity of a live plague vaccine in model animal experiments. Plague vaccine EV, polyoxidonium, betaleukin, erythrocytic antigenic diagnosticum for determination of F1 antibodies and immune reagents for detection of lymphocytes with F1 receptors (LFR) in adhesive test developed by the authors were used. The experiments were carried out in 12 rabbits and 169 guinea pigs. Immune modulation accelerated the appearance and disappearance of LFR (early phase) and ensured a more rapid and intensive antibody formation (effector phase). Activation by betaleukin is more pronounced than by polyoxidonium. The more rapid and intensive was the development of early phase, the more effective was antibody response to the vaccine. Immune modulation in the experiment with guinea pigs significantly increased protective activity of the vaccine. The use of immune modulators increased immunogenic (in both early and effector phases of antigen-specific response) and protective activity of the EV vaccine. A connection between the acceleration of the first phase of antigen-specific response and general intensity of effector phase of immune response to the EV vaccine was detected. ,

  20. Black plague.

    Science.gov (United States)

    Whitfield, L

    1997-01-01

    Many African-Americans are reluctant to participate in clinical trials of any type, citing the Federal government's unethical syphilis experiments in the Tuskegee Study. African-Americans are also more predisposed to choose alternative treatments over mainstream therapies. These attitudes contribute to the rise in infection rates in this population that now accounts for 41 percent of all reported cases. It is essential that African-Americans participate in HIV research at every level.

  1. Plague control in Kangbao county in 2001 -2010%2001-2010年康保县鼠疫防治情况

    Institute of Scientific and Technical Information of China (English)

    宁智波; 刘凤春; 吕少军; 闫东; 王治宇; 高文林; 王晓泓; 宋明; 杨建民; 是艾

    2012-01-01

    分析2001 -2010年康保县鼠疫监测资料及鼠疫防治情况,提出了预防控制对策.动物间鼠疫疫情活跃,坚持以鼠疫常规监测,宣传教育,灭鼠灭蚤,区域联防为主的综合防治是预防控制鼠疫的主要措施.%To analyze the plague controlling data and epidemiological characteristics in Kangbao county from 2001 to 2010,and provide the strategy for plague prevention and control. The plague among the animal is active, in order to control and prevent the plague ,the main continuous general measures such as plague monitoring, rat and flea eradication, educational difusion and provincial joint defense must be insisted on.

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

    Directory of Open Access Journals (Sweden)

    Xin Wang

    2017-03-01

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

  3. THE MYTHE NOVEL PLAGUE OF ALBERT CAMUS, ITS INSPIRATION SOURCES AND ITS EVOCATIVE SYMBOLS

    Directory of Open Access Journals (Sweden)

    Fuat BOYACIOĞLU

    2012-06-01

    Full Text Available In different periods, some writers made new comments on the antique classics mhytes by readapting them in accordance with the their period. In the XVIIth the french classic playwriters such as Pierre Corneille and Jean Racine took up again the antique myths treated by the antique writers. These playwriters readapted the antique myths in their works according to the conception of their period. In the XXth the french writers such as Jean Giraudoux, André Gide, Jean-Paul Sartre and Albert Camus interpreted again the antique mythes in their works by making evocations to the events occured in their epoch. Treating and displaying the antique mythes in the theater works is a well known fact, but it is an uncommon fact in the novels. The russian novelist Dostoïevsky, the czeche Franz Kafka, the american novelists Herman Melville and William Faulkner interpreted again some mythes under different aspects in their novels. This style of myth roman caused that the american critic Stock asked the following question: Is it possible to reconcile the symbolism and the naturalism, what is the principal and formal problem? The myth roman gives answer to the question : Do the realism and naturalism giving importance the exterior appearance of the matter and things and the symbolism giving importance to the the invisible aspect of the matter and things come together in the same plane? The novel of Albert Camus, The Plague (La Peste containing both realist –naturalist and symbolist elements constitutes an typical exemple of this myth roman. In this novel, Camus relates how the epidemic disease pestilence not occured in reality according to the historical documents, but fabricated fictively by the writer, besieges the algerian city Oran and causes a chaotic situation to the inhabitants as the enemy army did, in a given date, this is to say, in1940’s and a given space. This pestilence event as epidemic disease evokes symbolically the occupation of France by the

  4. Role of the Yersinia pestis Ail protein in preventing a protective polymorphonuclear leukocyte response during bubonic plague.

    Science.gov (United States)

    Hinnebusch, B Joseph; Jarrett, Clayton O; Callison, Julie A; Gardner, Donald; Buchanan, Susan K; Plano, Gregory V

    2011-12-01

    The ability of Yersinia pestis to forestall the mammalian innate immune response is a fundamental aspect of plague pathogenesis. In this study, we examined the effect of Ail, a 17-kDa outer membrane protein that protects Y. pestis against complement-mediated lysis, on bubonic plague pathogenesis in mice and rats. The Y. pestis ail mutant was attenuated for virulence in both rodent models. The attenuation was greater in rats than in mice, which correlates with the ability of normal rat serum, but not mouse serum, to kill ail-negative Y. pestis in vitro. Intradermal infection with the ail mutant resulted in an atypical, subacute form of bubonic plague associated with extensive recruitment of polymorphonuclear leukocytes (PMN or neutrophils) to the site of infection in the draining lymph node and the formation of large purulent abscesses that contained the bacteria. Systemic spread and mortality were greatly attenuated, however, and a productive adaptive immune response was generated after high-dose challenge, as evidenced by high serum antibody levels against Y. pestis F1 antigen. The Y. pestis Ail protein is an important bubonic plague virulence factor that inhibits the innate immune response, in particular the recruitment of a protective PMN response to the infected lymph node.

  5. A Yersinia pestis YscN ATPase mutant functions as a live attenuated vaccine against bubonic plague in mice.

    Science.gov (United States)

    Bozue, Joel; Cote, Christopher K; Webster, Wendy; Bassett, Anthony; Tobery, Steven; Little, Stephen; Swietnicki, Wieslaw

    2012-07-01

    Yersinia pestis is the causative agent responsible for bubonic and pneumonic plague. The bacterium uses the pLcr plasmid-encoded type III secretion system to deliver virulence factors into host cells. Delivery requires ATP hydrolysis by the YscN ATPase encoded by the yscN gene also on pLcr. A yscN mutant was constructed in the fully virulent CO92 strain containing a nonpolar, in-frame internal deletion within the gene. We demonstrate that CO92 with a yscN mutation was not able to secrete the LcrV protein (V-Antigen) and attenuated in a subcutaneous model of plague demonstrating that the YscN ATPase was essential for virulence. However, if the yscN mutant was complemented with a functional yscN gene in trans, virulence was restored. To evaluate the mutant as a live vaccine, Swiss-Webster mice were vaccinated twice with the ΔyscN mutant at varying doses and were protected against bubonic plague in a dose-dependent manner. Antibodies to F1 capsule but not to LcrV were detected in sera from the vaccinated mice. These preliminary results suggest a proof-of-concept for an attenuated, genetically engineered, live vaccine effective against bubonic plague. Published 2012. This article is a US Government work and is in the public domain in the USA.

  6. A recombinant raccoon poxvirus vaccine expressing both Yersinia pestis F1 and truncated V antigens protects animals against lethal plague.

    Science.gov (United States)

    Rocke, Tonie E.; Kingstad-Bakke, B; Berlier, W; Osorio, J.E.

    2014-01-01

    In previous studies, we demonstrated in mice and prairie dogs that simultaneous administration of two recombinant raccoon poxviruses (rRCN) expressing Yersinia pestis antigens (F1 and V307-a truncated version of the V protein) provided superior protection against plague challenge compared to individual single antigen constructs. To reduce costs of vaccine production and facilitate implementation of a sylvatic plague vaccine (SPV) control program for prairie dogs, a dual antigen construct is more desirable. Here we report the construction and characterization of a novel RCN-vectored vaccine that simultaneously expresses both F1 and V307 antigens. This dual antigen vaccine provided similar levels of protection against plague in both mice and prairie dogs as compared to simultaneous administration of the two single antigen constructs and was also shown to protect mice against an F1 negative strain of Y. pestis.. The equivalent safety, immunogenicity and efficacy profile of the dual RCN-F1/V307 construct warrants further evaluation in field efficacy studies in sylvatic plague endemic areas.

  7. Interannual variability of human plague occurrence in the Western United States explained by tropical and North Pacific Ocean climate variability.

    Science.gov (United States)

    Ari, Tamara Ben; Gershunov, Alexander; Tristan, Rouyer; Cazelles, Bernard; Gage, Kenneth; Stenseth, Nils C

    2010-09-01

    Plague is a vector-borne, highly virulent zoonotic disease caused by the bacterium Yersinia pestis. It persists in nature through transmission between its hosts (wild rodents) and vectors (fleas). During epizootics, the disease expands and spills over to other host species such as humans living in or close to affected areas. Here, we investigate the effect of large-scale climate variability on the dynamics of human plague in the western United States using a 56-year time series of plague reports (1950-2005). We found that El Niño Southern Oscillation and Pacific Decadal Oscillation in combination affect the dynamics of human plague over the western United States. The underlying mechanism could involve changes in precipitation and temperatures that impact both hosts and vectors. It is suggested that snow also may play a key role, possibly through its effects on summer soil moisture, which is known to be instrumental for flea survival and development and sustained growth of vegetation for rodents.

  8. Angels with Nanotech Wings: Magic, Medicine and Technology in Aronofksky's The Fountain, Gibson's The Neuromancer and Slonczewski's Brain Plague

    NARCIS (Netherlands)

    Lord, C.M.

    2009-01-01

    Darren Aronofsky's feature film The Fountain (2006), William Gibson's celebrated novel The Neuromancer (1984)and Joan Slonczewski'ls best-seller Brain Plague (2000), all have in common a preoccupation with the neuroscientific secrets of the brain. But more than this, all these works that explore the

  9. Consumption of baits containing raccoon pox-based plague vaccines protects black-tailed prairie dogs (Cynomys ludovicianus).

    Science.gov (United States)

    Rocke, Tonie E; Pussini, Nicola; Smith, Susan R; Williamson, Judy; Powell, Bradford; Osorio, Jorge E

    2010-01-01

    Baits containing recombinant raccoon poxvirus (RCN) expressing plague antigens (fraction 1 [F1] and a truncated form of the V protein-V307) were offered for voluntary consumption several times over the course of several months to a group of 16 black-tailed prairie dogs (Cynomys ludovicianus). For comparison, another group of prairie dogs (n = 12) was injected subcutaneously (SC) (prime and boost) with 40 microg of F1-V fusion protein absorbed to alum, a vaccine-adjuvant combination demonstrated to elicit immunity to plague in mice and other mammals. Control animals received baits containing RCN without the inserted antigen (n = 8) or injected diluent (n = 7), and as there was no difference in their survival rates by Kaplan-Meier analysis, all of them were combined into one group in the final analysis. Mean antibody titers to Yersinia pestis F1 and V antigen increased (p plague vaccines provides significant protection against challenge at dosages that simulate simultaneous delivery of the plague bacterium by numerous flea bites.

  10. Vaccination as a potential means to prevent plague in black-footed ferrets:progress and continuing challenges

    Science.gov (United States)

    Rocke, T.E.; Nol, P.; Marinari, P.E.; Kreeger, J.S.; Smith, S.R.; Andrews, G.P.; Friedlander, A.W.

    2006-01-01

    This study was conducted to further assess the feasibility of vaccinating black-footed ferrets (Mustela nigripes) against plague (caused by the bacterium Yersinia pestis). On days 0 and 28, 17 postreproductive ferrets were immunized by subcutaneous injection with a recombinant fusion protein containing F1 and V antigens from Y. pestis. Another 17 animals

  11. Possible vector dissemination by swift foxes following a plague epizootic in black-tailed prairie dogs in northwestern Texas.

    Science.gov (United States)

    McGee, Brady K; Butler, Matthew J; Pence, Danny B; Alexander, James L; Nissen, Janet B; Ballard, Warren B; Nicholson, Kerry L

    2006-04-01

    To determine whether swift foxes (Vulpes velox) could facilitate transmission of Yersinia pestis to uninfected black-tailed prairie dog (Cynomys ludovicianus) colonies by acquiring infected fleas, ectoparasite and serologic samples were collected from swift foxes living adjacent to prairie dog towns during a 2004 plague epizootic in northwestern Texas, USA. A previous study (1999-2001) indicated that these swift foxes were infested almost exclusively with the flea Pulex irritans. Black-tailed prairie dogs examined from the study area harbored only Pulex simulans and Oropsylla hirsuta. Although P. irritans was most common, P. simulans and O. hirsuta were collected from six swift foxes and a single coyote (Canis latrans) following the plague epizootic. Thus, both of these canids could act as transport hosts (at least temporarily) of prairie dog fleas following the loss of their normal hosts during a plague die-off. All six adult swift foxes tested positive for antibodies to Y. pestis. All 107 fleas from swift foxes tested negative for Y. pestis by mouse inoculation. Although swift foxes could potentially carry Y. pestis to un-infected prairie dog colonies, we believe they play only a minor role in plague epidemiology, considering that they harbored just a few uninfected prairie dog fleas (P. simulans and O. hirsuta).

  12. FLEAS OF BLACK-FOOTED FERRETS (MUSTELA NIGRIPES) AND THEIR POTENTIAL ROLE IN THE MOVEMENT OF PLAGUE.

    Science.gov (United States)

    Mize, Erica L; Grassel, Shaun M; Britten, Hugh B

    2017-07-01

    Sylvatic plague is one of the major impediments to the recovery of the black-footed ferret ( Mustela nigripes ) because it decimates their primary prey species, prairie dogs ( Cynomys spp.), and directly causes mortality in ferrets. Fleas are the primary vector of Yersinia pestis , the causative agent of sylvatic plague. The goal of this research was to better understand the flea fauna of ferrets and the factors that might influence flea abundance on ferrets. Fleas from ferrets were tested for Y. pestis in a post hoc assessment to investigate the plausibility that some ferrets could act as incidental transporter hosts of fleas infected with Y. pestis . Fleas were collected from ferrets captured on the Lower Brule Indian Reservation in central South Dakota, US from 2009 to 2012. A total of 528 fleas collected from 67 individual ferrets were identified and tested for the presence of Y. pestis with a nested PCR assay. The predominant flea recovered from ferrets was Oropsylla hirsuta , a species that comprises 70-100% of the fleas recovered from prairie dogs and their burrows in the study area. Yersinia pestis was detected at low levels in fleas collected from ferrets with prevalence ranging from 0% to 2.9%; male ferrets harbored significantly more fleas than female ferrets. Six of 67 ferrets vaccinated against plague carried fleas that tested positive for Y. pestis , which suggests ferrets vaccinated against plague could inadvertently act as incidental transporter hosts of Y. pestis -positive fleas.

  13. Convergent evolution in European and Rroma populations reveals pressure exerted by plague on Toll-like receptors

    NARCIS (Netherlands)

    Laayouni, Hafid; Oosting, Marije; Luisi, Pierre; Ioana, Mihai; Alonso, Santos; Ricaño Ponce, Isis; Trynka, Gosia; Zhernakova, Alexandra; Plantinga, Theo S.; Cheng, Shih-Chin; van der Meer, Jos W. M.; Popp, Radu; Sood, Ajit; Thelma, B. K.; Wijmenga, Cisca; Joosten, Leo A. B.; Bertranpetit, Jaume; Netea, Mihai G.

    2014-01-01

    Recent historical periods in Europe have been characterized by severe epidemic events such as plague, smallpox, or influenza that shaped the immune system of modern populations. This study aims to identify signals of convergent evolution of the immune system, based on the peculiar demographic

  14. Deltamethrin flea-control preserves genetic variability of black-tailed prairie dogs during a plague outbreak

    Science.gov (United States)

    Jones, P.H.; Biggins, D.E.; Eads, D.A.; Eads, S.L.; Britten, H.B.

    2012-01-01

    Genetic variability and structure of nine black-tailed prairie dog (BTPD, Cynomys ludovicianus) colonies were estimated with 15 unlinked microsatellite markers. A plague epizootic occurred between the first and second years of sampling and our study colonies were nearly extirpated with the exception of three colonies in which prairie dog burrows were previously dusted with an insecticide, deltamethrin, used to control fleas (vectors of the causative agent of plague, Yersinia pestis). This situation provided context to compare genetic variability and structure among dusted and non-dusted colonies pre-epizootic, and among the three dusted colonies pre- and post-epizootic. We found no statistical difference in population genetic structures between dusted and non-dusted colonies pre-epizootic. On dusted colonies, gene flow and recent migration rates increased from the first (pre-epizootic) year to the second (post-epizootic) year which suggested dusted colonies were acting as refugia for prairie dogs from surrounding colonies impacted by plague. Indeed, in the dusted colonies, estimated densities of adult prairie dogs (including dispersers), but not juveniles (non-dispersers), increased from the first year to the second year. In addition to preserving BTPDs and many species that depend on them, protecting colonies with deltamethrin or a plague vaccine could be an effective method to preserve genetic variability of prairie dogs. ?? 2011 Springer Science+Business Media B.V.

  15. A comprehensive study on the role of the Yersinia pestis virulence markers in an animal model of pneumonic plague

    NARCIS (Netherlands)

    W.E. Kaman (Wendy); S. Hawkey; D. van der Kleij (Desiree); M.P. Broekhuijsen; N.J. Silman; F.J. Bikker (Floris)

    2011-01-01

    textabstractWe determined the role of Yersinia pestis virulence markers in an animal model of pneumonic plague. Eleven strains of Y. pestis were characterized using PCR assays to detect the presence of known virulence genes both encoded by the three plasmids as well as chromosomal markers. The

  16. Interannual Variability of Human Plague Occurrence in the Western United States Explained by Tropical and North Pacific Ocean Climate Variability

    Science.gov (United States)

    Ari, Tamara Ben; Gershunov, Alexander; Tristan, Rouyer; Cazelles, Bernard; Gage, Kenneth; Stenseth, Nils C.

    2010-01-01

    Plague is a vector-borne, highly virulent zoonotic disease caused by the bacterium Yersinia pestis. It persists in nature through transmission between its hosts (wild rodents) and vectors (fleas). During epizootics, the disease expands and spills over to other host species such as humans living in or close to affected areas. Here, we investigate the effect of large-scale climate variability on the dynamics of human plague in the western United States using a 56-year time series of plague reports (1950–2005). We found that El Niño Southern Oscillation and Pacific Decadal Oscillation in combination affect the dynamics of human plague over the western United States. The underlying mechanism could involve changes in precipitation and temperatures that impact both hosts and vectors. It is suggested that snow also may play a key role, possibly through its effects on summer soil moisture, which is known to be instrumental for flea survival and development and sustained growth of vegetation for rodents. PMID:20810830

  17. A comprehensive study on the role of the Yersinia pestis virulence markers in an animal model of pneumonic plague

    NARCIS (Netherlands)

    Kaman, W.E.; Hawkey, S.; Kleij, D. van der; Broekhuijsen, M.P.; Silman, N.J.; Bikker, F.J.

    2011-01-01

    We determined the role of Yersinia pestis virulence markers in an animal model of pneumonic plague. Eleven strains of Y. pestis were characterized using PCR assays to detect the presence of known virulence genes both encoded by the three plasmids as well as chromosomal markers. The virulence of all

  18. [Morphofunctional evaluation of the state of cells of APUD-system biomodel during anti-plague vaccine process].

    Science.gov (United States)

    Bugorkova, S A; Kutyreva, V V

    2013-01-01

    Study reaction of cells of APUD-system of lymphoid organs and intestine of guinea pigs at the stages of morpho- and immunogenesis in response to administration of Yersinia pestis EV Research Institute of Epidemiology and Hygiene (RIEH) line vaccine strain. Vaccine process was modeled in guinea pigs during subcutaneous infection of animals with culture of Yersinia pestis EV RIEH line vaccine strain. Pieces of thymus, spleen, lymphatic nodes and an area of duodenum were taken for histological study. The preparations were stained by solution of hematoxylin and eosin, impregnated with silver by Grimelius and Masson in Hamperl modification. Dose-dependent character of effect of anti-plague vaccination on reaction of apudocytes in immunocompetent organs and duodenum biomodels was established, that indirectly reflects the direction of processes of immunogenesis in central and peripheral organs of immune system. Changes in quantity and morphofunctional state of apudocytes in the intestine of immunized guinea pigs gives evidence of the interest of this segment of APUD-system in the processes of immunogenesis during plague. Range of changes of quantity and functional state of apudocytes in lymphoid organs and intestine of animals during anti-plague vaccination was established. Quantitative parameters of morphofunctional state of intestine adipocytes that may be used for characterization of the intensity of adaptation-compensatory process in the organism of biomodels during modeling of any experimental vaccine process as well as an additional indirect indicator during evaluation of reactogenicity of live anti-plague vaccines were determined.

  19. [Flow-cytofluorometric study of bactericidal granules in blood phagocytes of animals with various species sensitivity to experimental plague infection].

    Science.gov (United States)

    Kravtsov, A L

    2015-01-01

    Compare the content of bactericidal granules (BG) in blood phagocytes of animals, that differ by species sensitivity to plague infection, under the conditions of measuring, that ensure automatic differentiating by this parameter of monocytes and granulocytes of human blood. Human whole blood leukocytes were studied, as well as from 7 animal species: mice, guinea pigs, golden hamsters, white rats, rabbits, dogs and horses. Acridine orange (AO) was used for supra-vital staining in primary (bactericidal) granule cells. Relative BG content was measured in separate cells in conventional units of red fluorescence intensity by flow cytofluorometry. Deficiency of AO molecules in BG, that correlates with deficiency of leukocyte elastase in cells, that is most pronounced in mice and lest pronounced in rabbits, was established to be characteristic for all the blood phagocytes of all the laboratory animal species sensitive to plague. Blood phagocytes of dogs and horses, that were non-sensitive to plague, differed by high heterogeneity by the studied parameter, and in horse blood innate immunity cells were detected, that contained 2.5 times higher amount of BG, than blood granulocytes of humans. Leukocyte BG, that have enzyme cationic proteins: elastase, cathepsin G, protease 3 and myeloperoxidase, play and important role in protection of organism from plague infection.

  20. Angels with Nanotech Wings: Magic, Medicine and Technology in Aronofksky's The Fountain, Gibson's The Neuromancer and Slonczewski's Brain Plague

    NARCIS (Netherlands)

    Lord, C.M.

    2009-01-01

    Darren Aronofsky's feature film The Fountain (2006), William Gibson's celebrated novel The Neuromancer (1984)and Joan Slonczewski'ls best-seller Brain Plague (2000), all have in common a preoccupation with the neuroscientific secrets of the brain. But more than this, all these works that explore the

  1. A comprehensive study on the role of the Yersinia pestis virulence markers in an animal model of pneumonic plague

    NARCIS (Netherlands)

    W.E. Kaman (Wendy); S. Hawkey; D. van der Kleij (Desiree); M.P. Broekhuijsen; N.J. Silman; F.J. Bikker (Floris)

    2011-01-01

    textabstractWe determined the role of Yersinia pestis virulence markers in an animal model of pneumonic plague. Eleven strains of Y. pestis were characterized using PCR assays to detect the presence of known virulence genes both encoded by the three plasmids as well as chromosomal markers. The virul

  2. A comprehensive study on the role of the Yersinia pestis virulence markers in an animal model of pneumonic plague

    NARCIS (Netherlands)

    Kaman, W.E.; Hawkey, S.; Kleij, D. van der; Broekhuijsen, M.P.; Silman, N.J.; Bikker, F.J.

    2011-01-01

    We determined the role of Yersinia pestis virulence markers in an animal model of pneumonic plague. Eleven strains of Y. pestis were characterized using PCR assays to detect the presence of known virulence genes both encoded by the three plasmids as well as chromosomal markers. The virulence of all

  3. A comprehensive study on the role of the Yersinia pestis virulence markers in an animal model of pneumonic plague

    NARCIS (Netherlands)

    Kaman, W.E.; Hawkey, S.; van der Kleij, D.; Broekhuijsen, M.P.; Silman, N.J.; Bikker, F.J.

    2011-01-01

    Yersinia pestis, the Gram-negative bacterial agent of plague, is a zoonotic pathogen that primarily infects wild rodents and is transmitted by fleas. Y. pestis is one of the most invasive and virulent bacterial pathogens and has caused devastating pandemics, including the Black Death of 14th century

  4. History of the Ming Dynasty Plague Disaster%明代瘟疫灾害史论

    Institute of Scientific and Technical Information of China (English)

    邱云飞

    2011-01-01

    在中国古代历史上,明代是我国瘟疫危害比较严重的一个时期,其间发生的瘟疫次数及危害在古代时期仅次于清朝,这一时期的瘟疫灾害在时间和地理分布上呈现一定的规律性,当时的人们在同瘟疫斗争的过程中也摸索很多有益的经验,尽其所能地减轻瘟疫造成的危害.%In ancient history, the Ming Dynasty was against a more serious epidemic in our country for a period, during which the frequency and hazards plague occurred in ancient times after the Qing Dynasty, the plague of disasters during this period of time and geographical distribution showed some regularity. People at that time in the course of the struggle with the plague also explored a lot of useful experience,did everything possible to reduce the harm caused by the plague.

  5. Comprehensive evaluation method and plague control and prevention%综合评价方法与鼠疫防治

    Institute of Scientific and Technical Information of China (English)

    魏荣杰; 王祖郧

    2014-01-01

    现代综合评价方法在医学实践中得到了广泛应用并取得了理想的效果,但在鼠疫防治领域,综合评价方法的使用尚不多见。挖掘鼠疫防治资源信息、选用适宜的综合评价方法对鼠疫防治工作进行综合评价,将有助于提高鼠疫防治工作效率,能够为进一步改进鼠疫防治工作模式、选用科学的防治策略和措施提供可靠依据。%Methods of modern comprehensive evaluation are seldom used in the field of plague control and prevention, which are used in the medicine widely and the ideal results was obtained. It will be useful to improve the plague con-trol and prevention then to provide the reliable reference for the modification of plague control and prevention by com-prehensive evaluating with the suitable method and plague information.

  6. A comprehensive study on the role of the Yersinia pestis virulence markers in an animal model of pneumonic plague

    NARCIS (Netherlands)

    W.E. Kaman (Wendy); S. Hawkey; D. van der Kleij (Desiree); M.P. Broekhuijsen; N.J. Silman; F.J. Bikker (Floris)

    2011-01-01

    textabstractWe determined the role of Yersinia pestis virulence markers in an animal model of pneumonic plague. Eleven strains of Y. pestis were characterized using PCR assays to detect the presence of known virulence genes both encoded by the three plasmids as well as chromosomal markers. The virul

  7. Yersinia pestis subverts the dermal neutrophil response in a mouse model of bubonic plague.

    Science.gov (United States)

    Shannon, Jeffrey G; Hasenkrug, Aaron M; Dorward, David W; Nair, Vinod; Carmody, Aaron B; Hinnebusch, B Joseph

    2013-08-27

    The majority of human Yersinia pestis infections result from introduction of bacteria into the skin by the bite of an infected flea. Once in the dermis, Y. pestis can evade the host's innate immune response and subsequently disseminate to the draining lymph node (dLN). There, the pathogen replicates to large numbers, causing the pathognomonic bubo of bubonic plague. In this study, several cytometric and microscopic techniques were used to characterize the early host response to intradermal (i.d.) Y. pestis infection. Mice were infected i.d. with fully virulent or attenuated strains of dsRed-expressing Y. pestis, and tissues were analyzed by flow cytometry. By 4 h postinfection, there were large numbers of neutrophils in the infected dermis and the majority of cell-associated bacteria were associated with neutrophils. We observed a significant effect of the virulence plasmid (pCD1) on bacterial survival and neutrophil activation in the dermis. Intravital microscopy of i.d. Y. pestis infection revealed dynamic interactions between recruited neutrophils and bacteria. In contrast, very few bacteria interacted with dendritic cells (DCs), indicating that this cell type may not play a major role early in Y. pestis infection. Experiments using neutrophil depletion and a CCR7 knockout mouse suggest that dissemination of Y. pestis from the dermis to the dLN is not dependent on neutrophils or DCs. Taken together, the results of this study show a very rapid, robust neutrophil response to Y. pestis in the dermis and that the virulence plasmid pCD1 is important for the evasion of this response. Yersinia pestis remains a public health concern today because of sporadic plague outbreaks that occur throughout the world and the potential for its illegitimate use as a bioterrorism weapon. Since bubonic plague pathogenesis is initiated by the introduction of Y. pestis into the skin, we sought to characterize the response of the host's innate immune cells to bacteria early after

  8. Yersinia pestis and the plague of Justinian 541-543 AD: a genomic analysis.

    Science.gov (United States)

    Wagner, David M; Klunk, Jennifer; Harbeck, Michaela; Devault, Alison; Waglechner, Nicholas; Sahl, Jason W; Enk, Jacob; Birdsell, Dawn N; Kuch, Melanie; Lumibao, Candice; Poinar, Debi; Pearson, Talima; Fourment, Mathieu; Golding, Brian; Riehm, Julia M; Earn, David J D; Dewitte, Sharon; Rouillard, Jean-Marie; Grupe, Gisela; Wiechmann, Ingrid; Bliska, James B; Keim, Paul S; Scholz, Holger C; Holmes, Edward C; Poinar, Hendrik

    2014-04-01

    Yersinia pestis has caused at least three human plague pandemics. The second (Black Death, 14-17th centuries) and third (19-20th centuries) have been genetically characterised, but there is only a limited understanding of the first pandemic, the Plague of Justinian (6-8th centuries). To address this gap, we sequenced and analysed draft genomes of Y pestis obtained from two individuals who died in the first pandemic. Teeth were removed from two individuals (known as A120 and A76) from the early medieval Aschheim-Bajuwarenring cemetery (Aschheim, Bavaria, Germany). We isolated DNA from the teeth using a modified phenol-chloroform method. We screened DNA extracts for the presence of the Y pestis-specific pla gene on the pPCP1 plasmid using primers and standards from an established assay, enriched the DNA, and then sequenced it. We reconstructed draft genomes of the infectious Y pestis strains, compared them with a database of genomes from 131 Y pestis strains from the second and third pandemics, and constructed a maximum likelihood phylogenetic tree. Radiocarbon dating of both individuals (A120 to 533 AD [plus or minus 98 years]; A76 to 504 AD [plus or minus 61 years]) places them in the timeframe of the first pandemic. Our phylogeny contains a novel branch (100% bootstrap at all relevant nodes) leading to the two Justinian samples. This branch has no known contemporary representatives, and thus is either extinct or unsampled in wild rodent reservoirs. The Justinian branch is interleaved between two extant groups, 0.ANT1 and 0.ANT2, and is distant from strains associated with the second and third pandemics. We conclude that the Y pestis lineages that caused the Plague of Justinian and the Black Death 800 years later were independent emergences from rodents into human beings. These results show that rodent species worldwide represent important reservoirs for the repeated emergence of diverse lineages of Y pestis into human populations. McMaster University, Northern

  9. Transmission efficiency of the plague pathogen (Y. pestis) by the flea, Xenopsylla skrjabini, to mice and great gerbils.

    Science.gov (United States)

    Zhang, Yujiang; Dai, Xiang; Wang, Qiguo; Chen, Hongjian; Meng, Weiwei; Wu, Kemei; Luo, Tao; Wang, Xinhui; Rehemu, Azhati; Guo, Rong; Yu, Xiaotao; Yang, Ruifu; Cao, Hanli; Song, Yajun

    2015-05-01

    Plague, a zoonotic disease caused by Yersinia pestis, is characterized by its ability to persist in the plague natural foci. Junggar Basin plague focus was recently identified in China, with Rhombomys opimus (great gerbils) and Xenopsylla skrjabini as the main reservoir and vector for plague. No transmission efficiency data of X. skrjabini for Y. pestis is available till now. In this study, we estimated the median infectious dose (ID50) and the blockage rates of X. skrjabini with Y. pestis, by using artificial feeders. We then evaluated the flea transmission ability of Y. pestis to the mice and great gerbils via artificial bloodmeal feeding. Finally, we investigated the transmission of Y. pestis to mice with fleas fed by infected great gerbils. ID50 of Y. pestis to X. skrjabini was estimated as 2.04 × 10(5) CFU (95% CI, 1.45 × 10(5) - 3.18 × 10(5) CFU), around 40 times higher than that of X. cheopis. Although fleas fed by higher bacteremia bloodmeal had higher infection rates for Y. pestis, they lived significantly shorter than their counterparts. X. skrjabini could get fully blocked as early as day 3 post of infection (7.1%, 3/42 fleas), and the overall blockage rate of X. cheopis was estimated as 14.9% (82/550 fleas) during the 14 days of investigation. For the fleas infected by artificial feeders, they seemed to transmit plague more efficiently to great gerbils than mice. Our single flea transmission experiments also revealed that, the transmission capacity of naturally infected fleas (fed by infected great gerbils) was significantly higher than that of artificially infected ones (fed by artificial feeders). Our results indicated that ID50 of Y. pestis to X. skrjabini was higher than other fleas like X. cheopis, and its transmission efficiency to mice might be lower than other flea vectors in the artificial feeding modes. We also found different transmission potentials in the artificially infected fleas and the naturally infected ones. Further studies are

  10. Contribution of land use to rodent flea load distribution in the plague endemic area of Lushoto District, Tanzania.

    Science.gov (United States)

    Hieronimo, Proches; Kihupi, Nganga I; Kimaro, Didas N; Gulinck, Hubert; Mulungu, Loth S; Msanya, Balthazar M; Leirs, Herwig; Deckers, Jozef A

    2014-07-01

    Fleas associated with different rodent species are considered as the major vectors of bubonic plague, which is still rampant in different parts of the world. The objective of this study was to investigate the contribution of land use to rodent flea load distribution at fine scale in the plague endemic area of north-eastern Tanzania. Data was collected in three case areas namely, Shume, Lukozi and Mwangoi, differing in plague incidence levels. Data collection was carried out during both wet and dry seasons of 2012. Analysis of Variance and Boosted Regression Tree (BRT) statistical methods were used to clarify the relationships between fleas and specific land use characteristics. There was a significant variation (P ≤ 0.05) of flea indices in different land use types. Fallow and natural forest had higher flea indices whereas plantation forest mono-crop and mixed annual crops had the lowest flea indices among the aggregated land use types. The influence of individual land use types on flea indices was variable with fallow having a positive effect and land tillage showing a negative effect. The results also demonstrated a seasonal effect, part of which can be attributed to different land use practices such as application of pesticides, or the presence of grass strips around fields. These findings suggest that land use factors have a major influence on rodent flea abundance which can be taken as a proxy for plague infection risk. The results further point to the need for a comprehensive package that includes land tillage and crop type considerations on one hand and the associated human activities on the other, in planning and implementation of plague control interventions.

  11. Beyond an AFLP genome scan towards the identification of immune genes involved in plague resistance in Rattus rattus from Madagascar.

    Science.gov (United States)

    Tollenaere, C; Jacquet, S; Ivanova, S; Loiseau, A; Duplantier, J-M; Streiff, R; Brouat, C

    2013-01-01

    Genome scans using amplified fragment length polymorphism (AFLP) markers became popular in nonmodel species within the last 10 years, but few studies have tried to characterize the anonymous outliers identified. This study follows on from an AFLP genome scan in the black rat (Rattus rattus), the reservoir of plague (Yersinia pestis infection) in Madagascar. We successfully sequenced 17 of the 22 markers previously shown to be potentially affected by plague-mediated selection and associated with a plague resistance phenotype. Searching these sequences in the genome of the closely related species Rattus norvegicus assigned them to 14 genomic regions, revealing a random distribution of outliers in the genome (no clustering). We compared these results with those of an in silico AFLP study of the R. norvegicus genome, which showed that outlier sequences could not have been inferred by this method in R. rattus (only four of the 15 sequences were predicted). However, in silico analysis allowed the prediction of AFLP markers distribution and the estimation of homoplasy rates, confirming its potential utility for designing AFLP studies in nonmodel species. The 14 genomic regions surrounding AFLP outliers (less than 300 kb from the marker) contained 75 genes encoding proteins of known function, including nine involved in immune function and pathogen defence. We identified the two interleukin 1 genes (Il1a and Il1b) that share homology with an antigen of Y. pestis, as the best candidates for genes subject to plague-mediated natural selection. At least six other genes known to be involved in proinflammatory pathways may also be affected by plague-mediated selection. © 2012 Blackwell Publishing Ltd.

  12. [The duration of preservation of plague pathogen strains with a different plasmid kit from a Central Caucasian high-altitude natural focus in the organism of citellophilus tesquorum fleas and the possibility of their transmission to laboratory animals].

    Science.gov (United States)

    Zharinova, N V; Zhilchenko, E B; Koniaeva, O A; Serdiuk, N S; Zaĭtseva, O A

    2013-01-01

    Two plasmid variants of the main subspecies of the plague microbe circulate in a Central Caucasian high-altitude natural focus of plague. The strains of one plasmid variant fully correspond to the main subspecies of the plague pathogen in their characteristics. Those of the other are auxotrophic for proline, weakly virulent to one or both species of laboratory animals. The mountain subspecies of Citellophilus tesquorum fleas excretes the greatest quantity of plague microbe strains so the investigation of whether unblocked fleas can transmit the plague microbe is of interest.

  13. Analysis of the sensitivity properties of a model of vector-borne bubonic plague.

    Science.gov (United States)

    Buzby, Megan; Neckels, David; Antolin, Michael F; Estep, Donald

    2008-09-06

    Model sensitivity is a key to evaluation of mathematical models in ecology and evolution, especially in complex models with numerous parameters. In this paper, we use some recently developed methods for sensitivity analysis to study the parameter sensitivity of a model of vector-borne bubonic plague in a rodent population proposed by Keeling & Gilligan. The new sensitivity tools are based on a variational analysis involving the adjoint equation. The new approach provides a relatively inexpensive way to obtain derivative information about model output with respect to parameters. We use this approach to determine the sensitivity of a quantity of interest (the force of infection from rats and their fleas to humans) to various model parameters, determine a region over which linearization at a specific parameter reference point is valid, develop a global picture of the output surface, and search for maxima and minima in a given region in the parameter space.

  14. Ecological Opportunity, Evolution, and the Emergence of Flea-Borne Plague.

    Science.gov (United States)

    Hinnebusch, B Joseph; Chouikha, Iman; Sun, Yi-Cheng

    2016-07-01

    The plague bacillus Yersinia pestis is unique among the pathogenic Enterobacteriaceae in utilizing an arthropod-borne transmission route. Transmission by fleabite is a recent evolutionary adaptation that followed the divergence of Y. pestis from the closely related food- and waterborne enteric pathogen Yersinia pseudotuberculosis A combination of population genetics, comparative genomics, and investigations of Yersinia-flea interactions have disclosed the important steps in the evolution and emergence of Y. pestis as a flea-borne pathogen. Only a few genetic changes, representing both gene gain by lateral transfer and gene loss by loss-of-function mutation (pseudogenization), were fundamental to this process. The emergence of Y. pestis fits evolutionary theories that emphasize ecological opportunity in adaptive diversification and rapid emergence of new species. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  15. Plague bacterium as a transformer species in prairie dogs and the grasslands of western North America.

    Science.gov (United States)

    Eads, David A; Biggins, Dean E

    2015-08-01

    Invasive transformer species change the character, condition, form, or nature of ecosystems and deserve considerable attention from conservation scientists. We applied the transformer species concept to the plague bacterium Yersinia pestis in western North America, where the pathogen was introduced around 1900. Y. pestis transforms grassland ecosystems by severely depleting the abundance of prairie dogs (Cynomys spp.) and thereby causing declines in native species abundance and diversity, including threatened and endangered species; altering food web connections; altering the import and export of nutrients; causing a loss of ecosystem resilience to encroaching invasive plants; and modifying prairie dog burrows. Y. pestis poses an important challenge to conservation biologists because it causes trophic-level perturbations that affect the stability of ecosystems. Unfortunately, understanding of the effects of Y. pestis on ecosystems is rudimentary, highlighting an acute need for continued research. © 2015 Society for Conservation Biology.

  16. The use of polyvinyl alcohol glutaraldehyde as solid-phase in ELISA for plague

    Directory of Open Access Journals (Sweden)

    Aureci Maria Araujo

    1996-04-01

    Full Text Available Discs of polyvinyl alcohol cross-linked with glutaraldehyde were synthesized under acid catalysis (H2SO4. Then, the antigen F1 purified from Yersinia pestis was covalently linked to this modified polymer. Afterwards, an enzyme-linked immunosorbent assay (ELISA was established for the diagnosis of plague in rabbit and human. The best conditions for the method were achieved by using 1.3 ¼g of F1 prepared in 0.067 M phosphate buffer, pH 7.2, containing 1 M NaCl (PBS; anti-IgG peroxidase conjugate diluted 6,000 times and as a blocking agent 3% w/v skim milk in PBS. The titration of positive rabbit serum according to this procedure detected antibody concentrations up to 1:12,800 times. The present method, the conventional ELISA and passive haemagglutination assay are compared.

  17. Evaluation of systemic insecticides mixed in rodenticide baits for plague vector control

    DEFF Research Database (Denmark)

    Larsen, Kim Søholt; Lodal, Jens

    1997-01-01

    Rodenticide baits containing systemic insecticides were evaluated in the laboratory for their palatability to the house rat Rattus rattus and for their toxicity against the oriental rat flea Xenopsylla cheopis - both animals are important Vectors of plague in Africa. The test bait and a non......-poisonous alternative were given to the rats for four days. The evaluation of the effectiveness was based on mortality and poison bait intake in percent of the total consumption. Different concentrations of technical material and different types of encapsulation of the three insecticides phoxim, fenthion and dimethoate...... were used in the tests. The rodenticide used was 0.005 % bromadiolone. For all three insecticides, a reduced intake of the poisonous bait was observed compared with the test of bromadiolone without insecticide. Based on the acceptance of the baits, the dimethoate encapsulated with beef tallow only...

  18. Temperature-sensitive mutants of fowl plague virus: isolation and genetic characterization. [UV radiation

    Energy Technology Data Exchange (ETDEWEB)

    Almond, J.W.; McGeoch, D.; Barry, R.D.

    1979-01-30

    Forty-nine temperature-sensitive mutants of fowl plague virus (FPV) strain Rostock and four ts mutants of FPV-strain Dobson were isolated by utilizing two methods of plaque screening, after either spontaneous or chemically induced mutagenesis. Twenty-nine of the FPV-Rostock mutants were further characterized by genetic recombination studies and were found to fall into six high frequency recombination groups. The genome segment carrying the ts mutation in each group was identified by analyzing the gene composition of ts/sup +/ recombinants generated from crosses between representatives of each group and ts mutants of FPV-Dobson. It was concluded that the six groups correspond to mutations in six different genome segments, namely, those coding for the P/sub 1/, P/sub 2/, P/sub 3/, HA, NP, and NS proteins.

  19. Phage therapy of the white plague-like disease of Favia favus in the Red Sea

    Science.gov (United States)

    Atad, I.; Zvuloni, A.; Loya, Y.; Rosenberg, E.

    2012-09-01

    Coral disease is a major factor in the global decline of coral reefs. At present, there are no known procedures for preventing or treating infectious diseases of corals. Immunization is not possible because corals have a restricted adaptive immune system and antibiotics are neither ecologically safe nor practical in an open system. Thus, we tested phage therapy as an alternative therapeutic method for treating diseased corals. Phage BA3, specific to the coral pathogen Thalassomonas loyana, inhibited the progression of the white plague-like disease and transmission to healthy corals in the Gulf of Aqaba, Red Sea. Only one out of 19 (5 %) of the healthy corals became infected when placed near phage-treated diseased corals, whereas 11 out of 18 (61 %) healthy corals were infected in the no-phage control. This is the first successful treatment for a coral disease in the sea. We posit that phage therapy of certain coral diseases is achievable in situ.

  20. INVESTIGATING A MURDER THE CASE OF THE JUSTINIANIC PLAGUE IN SCYTHIA MINOR

    Directory of Open Access Journals (Sweden)

    Dragos Mitrofan

    2015-03-01

    Full Text Available The study beforehand applies a logical scheme of analysis over a possible presence of the Justinianic plague in the province of Scythia Minor. Following a logic borrowed from the criminalistics, we tried to apply this scheme in order to see if the theory of presence of the epidemic is viable in the given region. Although we have not come with decisive pieces of evidence, a great deal of research is still necessary in order to confirm or infirm this theory. We therefore aim to open a discussion, considering the problem plausible, for the disease had the means and opportunity to affect the province. As previously stated this study is merely a plan of study that shall be developed in a forthcoming work.

  1. Validation of inverse seasonal peak mortality in medieval plagues, including the Black Death, in comparison to modern Yersinia pestis-variant diseases.

    Directory of Open Access Journals (Sweden)

    Mark R Welford

    Full Text Available BACKGROUND: Recent studies have noted myriad qualitative and quantitative inconsistencies between the medieval Black Death (and subsequent "plagues" and modern empirical Y. pestis plague data, most of which is derived from the Indian and Chinese plague outbreaks of A.D. 1900+/-15 years. Previous works have noted apparent differences in seasonal mortality peaks during Black Death outbreaks versus peaks of bubonic and pneumonic plagues attributed to Y. pestis infection, but have not provided spatiotemporal statistical support. Our objective here was to validate individual observations of this seasonal discrepancy in peak mortality between historical epidemics and modern empirical data. METHODOLOGY/PRINCIPAL FINDINGS: We compiled and aggregated multiple daily, weekly and monthly datasets of both Y. pestis plague epidemics and suspected Black Death epidemics to compare seasonal differences in mortality peaks at a monthly resolution. Statistical and time series analyses of the epidemic data indicate that a seasonal inversion in peak mortality does exist between known Y. pestis plague and suspected Black Death epidemics. We provide possible explanations for this seasonal inversion. CONCLUSIONS/SIGNIFICANCE: These results add further evidence of inconsistency between historical plagues, including the Black Death, and our current understanding of Y. pestis-variant disease. We expect that the line of inquiry into the disputed cause of the greatest recorded epidemic will continue to intensify. Given the rapid pace of environmental change in the modern world, it is crucial that we understand past lethal outbreaks as fully as possible in order to prepare for future deadly pandemics.

  2. Validation of inverse seasonal peak mortality in medieval plagues, including the Black Death, in comparison to modern Yersinia pestis-variant diseases.

    Science.gov (United States)

    Welford, Mark R; Bossak, Brian H

    2009-12-22

    Recent studies have noted myriad qualitative and quantitative inconsistencies between the medieval Black Death (and subsequent "plagues") and modern empirical Y. pestis plague data, most of which is derived from the Indian and Chinese plague outbreaks of A.D. 1900+/-15 years. Previous works have noted apparent differences in seasonal mortality peaks during Black Death outbreaks versus peaks of bubonic and pneumonic plagues attributed to Y. pestis infection, but have not provided spatiotemporal statistical support. Our objective here was to validate individual observations of this seasonal discrepancy in peak mortality between historical epidemics and modern empirical data. We compiled and aggregated multiple daily, weekly and monthly datasets of both Y. pestis plague epidemics and suspected Black Death epidemics to compare seasonal differences in mortality peaks at a monthly resolution. Statistical and time series analyses of the epidemic data indicate that a seasonal inversion in peak mortality does exist between known Y. pestis plague and suspected Black Death epidemics. We provide possible explanations for this seasonal inversion. These results add further evidence of inconsistency between historical plagues, including the Black Death, and our current understanding of Y. pestis-variant disease. We expect that the line of inquiry into the disputed cause of the greatest recorded epidemic will continue to intensify. Given the rapid pace of environmental change in the modern world, it is crucial that we understand past lethal outbreaks as fully as possible in order to prepare for future deadly pandemics.

  3. Epidemiologic analysis of a previous outbreak of bubonic plague:The first identified outbreak with bacteriological confirmation in Kobe and Osaka,Japan

    Institute of Scientific and Technical Information of China (English)

    Hiroshi Nishiura

    2009-01-01

    Objective:To characterize the case fatality and estimate the symptomatic period of bubonic plague.Methods:Epidemiologic analyses of a previous outbreak of plague in Osaka and Kobe,two major port cities in Japan, from 1899-1900 were performed.In addition to date of onset of symptoms,gender,age and the date of death were extracted from the historical data.The time from onset to death (symptomatic period)was fitted to gamma distribution using the maximum likelihood method.Results:Temporal distribution revealed suspected chains of transmission of the primary pneumonic plague at the late stage of the outbreak.The case fatality of bubonic plague without specific treatment was 83.4 %,and the mean time from onset to death was estimated as 4.7 days (95 % confidence interval:4.0,5.5).Conclusion:Case fatality of bubonic plague without specific treatment was extremely high.The symptomatic period of bubonic plague appeared to be longer than that of pneumonic plague.

  4. Efficacy of ciprofloxacin-gentamicin combination therapy in murine bubonic plague.

    Directory of Open Access Journals (Sweden)

    Nadine Lemaître

    Full Text Available Potential benefits of combination antibiotic therapy for the treatment of plague have never been evaluated. We compared the efficacy of a ciprofloxacin (CIN and gentamicin (GEN combination therapy with that of each antibiotic administered alone (i against Yersinia pestis in vitro and (ii in a mouse model of bubonic plague in which animals were intravenously injected with antibiotics for five days, starting at two different times after infection (44 h and 56 h. In vitro, the CIN+GEN combination was synergistic at 0.5x the individual drugs' MICs and indifferent at 1x- or 2x MIC. In vivo, the survival rate for mice treated with CIN+GEN was similar to that observed with CIN alone and slightly higher than that observed for GEN alone 100, 100 and 85%, respectively when treatment was started 44 h post challenge. 100% of survivors were recorded in the CIN+GEN group vs 86 and 83% in the CIN and GEN groups, respectively when treatment was delayed to 56 h post-challenge. However, these differences were not statistically significant. Five days after the end of treatment, Y. pestis were observed in lymph nodes draining the inoculation site (but not in the spleen in surviving mice in each of the three groups. The median lymph node log(10 CFU recovered from persistently infected lymph nodes was significantly higher with GEN than with CIN (5.8 vs. 3.2, p = 0.04 or CIN+GEN (5.8 vs. 2.8, p = 0.01. Taken as the whole, our data show that CIN+GEN combination is as effective as CIN alone but, regimens containing CIN are more effective to eradicate Y. pestis from the draining lymph node than the recommended GEN monotherapy. Moreover, draining lymph nodes may serve as a reservoir for the continued release of Y. pestis into the blood - even after five days of intravenous antibiotic treatment.

  5. RovA, a global regulator of Yersinia pestis, specifically required for bubonic plague.

    Science.gov (United States)

    Cathelyn, Jason S; Crosby, Seth D; Lathem, Wyndham W; Goldman, William E; Miller, Virginia L

    2006-09-05

    The pathogenic species of Yersinia contain the transcriptional regulator RovA. In Yersinia pseudotuberculosis and Yersinia enterocolitica, RovA regulates expression of the invasion factor invasin (inv), which mediates translocation across the intestinal epithelium. A Y. enterocolitica rovA mutant has a significant decrease in virulence by LD(50) analysis and an altered rate of dissemination compared with either wild type or an inv mutant, suggesting that RovA regulates multiple virulence factors. Here, we show the involvement of RovA in the virulence of Yersinia pestis, which naturally lacks a functional inv gene. A Y. pestis DeltarovA mutant is attenuated approximately 80-fold by LD(50) and is defective in dissemination/colonization of spleens and lungs after s.c. inoculation. However, the DeltarovA mutant is only slightly attenuated when given via an intranasal or i.p. route, indicating a more important role for RovA in bubonic plague than pneumonic plague or systemic infection. Microarray analysis was used to define the RovA regulon. The psa locus was among the most highly down-regulated loci in the DeltarovA mutant. A DeltapsaA mutant had a significant dissemination defect after s.c. infection but only slight attenuation by the pneumonic-disease model, closely mimicking the virulence defect seen with the DeltarovA mutant. DNA-binding studies revealed that RovA specifically interacts with the psaE and psaA promoter regions, indicating a direct role for RovA in regulating this locus. Thus, RovA appears to be a global transcription factor in Y. pestis and, through its regulatory influence on genes such as psaEFABC, contributes to the virulence of Y. pestis.

  6. Efficacy of ciprofloxacin-gentamicin combination therapy in murine bubonic plague.

    Science.gov (United States)

    Lemaître, Nadine; Ricard, Isabelle; Pradel, Elizabeth; Foligné, Benoît; Courcol, René; Simonet, Michel; Sebbane, Florent

    2012-01-01

    Potential benefits of combination antibiotic therapy for the treatment of plague have never been evaluated. We compared the efficacy of a ciprofloxacin (CIN) and gentamicin (GEN) combination therapy with that of each antibiotic administered alone (i) against Yersinia pestis in vitro and (ii) in a mouse model of bubonic plague in which animals were intravenously injected with antibiotics for five days, starting at two different times after infection (44 h and 56 h). In vitro, the CIN+GEN combination was synergistic at 0.5x the individual drugs' MICs and indifferent at 1x- or 2x MIC. In vivo, the survival rate for mice treated with CIN+GEN was similar to that observed with CIN alone and slightly higher than that observed for GEN alone 100, 100 and 85%, respectively when treatment was started 44 h post challenge. 100% of survivors were recorded in the CIN+GEN group vs 86 and 83% in the CIN and GEN groups, respectively when treatment was delayed to 56 h post-challenge. However, these differences were not statistically significant. Five days after the end of treatment, Y. pestis were observed in lymph nodes draining the inoculation site (but not in the spleen) in surviving mice in each of the three groups. The median lymph node log(10) CFU recovered from persistently infected lymph nodes was significantly higher with GEN than with CIN (5.8 vs. 3.2, p = 0.04) or CIN+GEN (5.8 vs. 2.8, p = 0.01). Taken as the whole, our data show that CIN+GEN combination is as effective as CIN alone but, regimens containing CIN are more effective to eradicate Y. pestis from the draining lymph node than the recommended GEN monotherapy. Moreover, draining lymph nodes may serve as a reservoir for the continued release of Y. pestis into the blood - even after five days of intravenous antibiotic treatment.

  7. La peste, enfermedad infectocontagiosa reemergente Re-emergence of the plague: an infectious and contagious disease

    Directory of Open Access Journals (Sweden)

    Plácido Pedroso Flaquet

    2010-06-01

    Full Text Available La peste es una enfermedad infectocontagiosa reemergente. Su reservorio natural en los vertebrados son los roedores silvestres. Los conejos y las liebres, los carnívoros silvestres y los gatos domésticos también pueden ser fuente de infección para los seres humanos. Es causada por la bacteria Yersinia pestis y transmitida por la pulga Xenopsylla cheopis que afecta tanto a animales como a humanos. Causó una devastadora pandemia que asoló Europa en el siglo XIV. Es una zoonosis muy virulenta y potencialmente letal enfermedad bacteriana. Sigue persistiendo en focos naturales que producen brotes recurrentes en muchos lugares del mundo La peste se contrae de manera natural por la intromisión de las personas en el ciclo zoonótico, o por la introducción de roedores silvestres o sus pulgas infectadas en el habitad de los seres humanos. La prevención y las medidas de control van encaminadas a la disminución y el control de roedores y pulgas.Plague is a re-emergent infectious and contagious disease. Its natural reservoirs in vertebrates are the wild rodents. Rabbits and hares, the wild carnivores and the domestic cats also may be an infection source for human beings. It is caused by Yersinia pestis and transmitted by the flea Xenopsylla cheopis affecting both animals and humans. In Europe during XIX century it caused a devastating pandemic. It is a zoonosis very virulent and a potentially lethal bacterial disease. It persists in natural foci producing recurrent outbreak in many world places. Plague is acquired in a natural way due to interference of people in the zoonosis cycle or due to introduction of wild rodents or their infected fleas in human beings habitat. Prevention and control measures must to be aimed to decrease and the control of rodents and fleas.

  8. [Control and eradication strategies for classic fowl plague in Germany and the European Union].

    Science.gov (United States)

    Werner, Ortrud; Harder, Timm C

    2006-01-01

    The huge potential economic impact of highly pathogenic avian influenza (HPAI) substantiates specific and rigorous legal regulations worldwide. According to the O.I.E. Terrestrial Animal Health Code fowl plague is a notifiable disease. International trading activities concerning poultry and poultry products originating from countries with active HPAI are rigorously restricted. In EU member states directive 92/40/EEC subsumes measures against fowl plague and has been transferred into German legislation by the "Geflügelpest-Verordnung". These acts specify that vaccination against HPAI is principally prohibited. The aim of all sanctions is the extinction of disease and the eradication of the causative agent. However, HPAI viruses, exclusively belonging to subtypes H5 and H7, can re-emerge de novo from progenitor viruses of low pathogenicity which are perpetuated in the wild bird population. An outbreak of HPAI requires prompt action by a stamping out strategy. Fast and accurate diagnosis, a strict stand-still and the culling of affected flocks are at the basis of success. In areas with a high density of poultry holdings preemptive culling and creation of buffer zones, devoid of susceptible poultry, may be neccessary. In these cases emergency vaccinations can be considered as a supportive measure in order to limit mass culling. Vaccinations on merely prophylactic grounds, not being connected to acute outbreaks, should be avoided beware of selective pressures on the virus leading to antigenic drift and escape of vaccine-induced immunity. Instead, high standard biosecurity measures, particularly limiting direct and indirect contacts with wild birds, should be maintained.

  9. Improvement of disease prediction and modeling through the use of meteorological ensembles: human plague in Uganda.

    Directory of Open Access Journals (Sweden)

    Sean M Moore

    Full Text Available Climate and weather influence the occurrence, distribution, and incidence of infectious diseases, particularly those caused by vector-borne or zoonotic pathogens. Thus, models based on meteorological data have helped predict when and where human cases are most likely to occur. Such knowledge aids in targeting limited prevention and control resources and may ultimately reduce the burden of diseases. Paradoxically, localities where such models could yield the greatest benefits, such as tropical regions where morbidity and mortality caused by vector-borne diseases is greatest, often lack high-quality in situ local meteorological data. Satellite- and model-based gridded climate datasets can be used to approximate local meteorological conditions in data-sparse regions, however their accuracy varies. Here we investigate how the selection of a particular dataset can influence the outcomes of disease forecasting models. Our model system focuses on plague (Yersinia pestis infection in the West Nile region of Uganda. The majority of recent human cases have been reported from East Africa and Madagascar, where meteorological observations are sparse and topography yields complex weather patterns. Using an ensemble of meteorological datasets and model-averaging techniques we find that the number of suspected cases in the West Nile region was negatively associated with dry season rainfall (December-February and positively with rainfall prior to the plague season. We demonstrate that ensembles of available meteorological datasets can be used to quantify climatic uncertainty and minimize its impacts on infectious disease models. These methods are particularly valuable in regions with sparse observational networks and high morbidity and mortality from vector-borne diseases.

  10. Improvement of disease prediction and modeling through the use of meteorological ensembles: human plague in Uganda.

    Science.gov (United States)

    Moore, Sean M; Monaghan, Andrew; Griffith, Kevin S; Apangu, Titus; Mead, Paul S; Eisen, Rebecca J

    2012-01-01

    Climate and weather influence the occurrence, distribution, and incidence of infectious diseases, particularly those caused by vector-borne or zoonotic pathogens. Thus, models based on meteorological data have helped predict when and where human cases are most likely to occur. Such knowledge aids in targeting limited prevention and control resources and may ultimately reduce the burden of diseases. Paradoxically, localities where such models could yield the greatest benefits, such as tropical regions where morbidity and mortality caused by vector-borne diseases is greatest, often lack high-quality in situ local meteorological data. Satellite- and model-based gridded climate datasets can be used to approximate local meteorological conditions in data-sparse regions, however their accuracy varies. Here we investigate how the selection of a particular dataset can influence the outcomes of disease forecasting models. Our model system focuses on plague (Yersinia pestis infection) in the West Nile region of Uganda. The majority of recent human cases have been reported from East Africa and Madagascar, where meteorological observations are sparse and topography yields complex weather patterns. Using an ensemble of meteorological datasets and model-averaging techniques we find that the number of suspected cases in the West Nile region was negatively associated with dry season rainfall (December-February) and positively with rainfall prior to the plague season. We demonstrate that ensembles of available meteorological datasets can be used to quantify climatic uncertainty and minimize its impacts on infectious disease models. These methods are particularly valuable in regions with sparse observational networks and high morbidity and mortality from vector-borne diseases.

  11. Improvement of Disease Prediction and Modeling through the Use of Meteorological Ensembles: Human Plague in Uganda

    Science.gov (United States)

    Moore, Sean M.; Monaghan, Andrew; Griffith, Kevin S.; Apangu, Titus; Mead, Paul S.; Eisen, Rebecca J.

    2012-01-01

    Climate and weather influence the occurrence, distribution, and incidence of infectious diseases, particularly those caused by vector-borne or zoonotic pathogens. Thus, models based on meteorological data have helped predict when and where human cases are most likely to occur. Such knowledge aids in targeting limited prevention and control resources and may ultimately reduce the burden of diseases. Paradoxically, localities where such models could yield the greatest benefits, such as tropical regions where morbidity and mortality caused by vector-borne diseases is greatest, often lack high-quality in situ local meteorological data. Satellite- and model-based gridded climate datasets can be used to approximate local meteorological conditions in data-sparse regions, however their accuracy varies. Here we investigate how the selection of a particular dataset can influence the outcomes of disease forecasting models. Our model system focuses on plague (Yersinia pestis infection) in the West Nile region of Uganda. The majority of recent human cases have been reported from East Africa and Madagascar, where meteorological observations are sparse and topography yields complex weather patterns. Using an ensemble of meteorological datasets and model-averaging techniques we find that the number of suspected cases in the West Nile region was negatively associated with dry season rainfall (December-February) and positively with rainfall prior to the plague season. We demonstrate that ensembles of available meteorological datasets can be used to quantify climatic uncertainty and minimize its impacts on infectious disease models. These methods are particularly valuable in regions with sparse observational networks and high morbidity and mortality from vector-borne diseases. PMID:23024750

  12. Characterization of a Cynomolgus Macaque Model of Pneumonic Plague for Evaluation of Vaccine Efficacy.

    Science.gov (United States)

    Fellows, Patricia; Price, Jessica; Martin, Shannon; Metcalfe, Karen; Krile, Robert; Barnewall, Roy; Hart, Mary Kate; Lockman, Hank

    2015-09-01

    The efficacy of a recombinant plague vaccine (rF1V) was evaluated in cynomolgus macaques (CMs) to establish the relationship among vaccine doses, antibody titers, and survival following an aerosol challenge with a lethal dose of Yersinia pestis strain Colorado 92. CMs were vaccinated with a range of rF1V doses on a three-dose schedule (days 0, 56, and 121) to provide a range of survival outcomes. The humoral immune response following vaccination was evaluated with anti-rF1, anti-rV, and anti-rF1V bridge enzyme-linked immunosorbent assays (ELISAs). Animals were challenged via aerosol exposure on day 149. Vaccine doses and antibody responses were each significantly associated with the probability of CM survival (P plague in a dose-dependent manner. There were statistically significant correlations between the vaccine dose and the time to onset of fever (P < 0.0001), the time from onset of fever to death (P < 0.0001), the time to onset of elevated respiratory rate (P = 0.0003), and the time to onset of decreased activity (P = 0.0251) postinfection in animals exhibiting these clinical signs. Delays in the onset of these clinical signs of disease were associated with larger doses of rF1V. Immunization with ≥ 12 μg of rF1V resulted in 100% CM survival. Since both the vaccine dose and anti-rF1V antibody titers correlate with survival, rF1V bridge ELISA titers can be used as a correlate of protection. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  13. Oral administration of a recombinant attenuated Yersinia pseudotuberculosis strain elicits protective immunity against plague.

    Science.gov (United States)

    Sun, Wei; Sanapala, Shilpa; Rahav, Hannah; Curtiss, Roy

    2015-11-27

    A Yersinia pseudotuberculosis PB1+ (Yptb PB1+) mutant strain combined with chromosome insertion of the caf1R-caf1A-caf1M-caf1 operon and deletions of yopJ and yopK, χ10068 [pYV-ω2 (ΔyopJ315 ΔyopK108) ΔlacZ044::caf1R-caf1M-caf1A-caf1] was constructed. Results indicated that gene insertion and deletion did not affect the growth rate of χ10068 compared to wild-type Yptb cultured at 26 °C. In addition, the F1 antigen in χ10068 was synthesized and secreted on the surface of bacteria at 37 °C (mammalian body temperature), not at ambient culture temperature (26 °C). Immunization with χ10068 primed antibody responses and specific T-cell responses to F1 and YpL (Y. pestis whole cell lysate). Oral immunization with a single dose of χ10068 provided 70% protection against a subcutaneous (s.c.) challenge with ∼ 2.6 × 10(5) LD50 of Y. pestis KIM6+ (pCD1Ap) (KIM6+Ap) and 90% protection against an intranasal (i.n.) challenge with ∼ 500 LD50 of KIM6+Ap in mice. Our results suggest that χ10068 can be used as an effective precursor to make a safe vaccine to prevent plague in humans and to eliminate plague circulation among humans and animals. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Circumventing Y. pestis Virulence by Early Recruitment of Neutrophils to the Lungs during Pneumonic Plague.

    Directory of Open Access Journals (Sweden)

    Yaron Vagima

    2015-05-01

    Full Text Available Pneumonic plague is a fatal disease caused by Yersinia pestis that is associated with a delayed immune response in the lungs. Because neutrophils are the first immune cells recruited to sites of infection, we investigated the mechanisms responsible for their delayed homing to the lung. During the first 24 hr after pulmonary infection with a fully virulent Y. pestis strain, no significant changes were observed in the lungs in the levels of neutrophils infiltrate, expression of adhesion molecules, or the expression of the major neutrophil chemoattractants keratinocyte cell-derived chemokine (KC, macrophage inflammatory protein 2 (MIP-2 and granulocyte colony stimulating factor (G-CSF. In contrast, early induction of chemokines, rapid neutrophil infiltration and a reduced bacterial burden were observed in the lungs of mice infected with an avirulent Y. pestis strain. In vitro infection of lung-derived cell-lines with a YopJ mutant revealed the involvement of YopJ in the inhibition of chemoattractants expression. However, the recruitment of neutrophils to the lungs of mice infected with the mutant was still delayed and associated with rapid bacterial propagation and mortality. Interestingly, whereas KC, MIP-2 and G-CSF mRNA levels in the lungs were up-regulated early after infection with the mutant, their protein levels remained constant, suggesting that Y. pestis may employ additional mechanisms to suppress early chemoattractants induction in the lung. It therefore seems that prevention of the early influx of neutrophils to the lungs is of major importance for Y. pestis virulence. Indeed, pulmonary instillation of KC and MIP-2 to G-CSF-treated mice infected with Y. pestis led to rapid homing of neutrophils to the lung followed by a reduction in bacterial counts at 24 hr post-infection and improved survival rates. These observations shed new light on the virulence mechanisms of Y. pestis during pneumonic plague, and have implications for the

  15. 阿拉善黄鼠疫源地鼠疫疫情动态分析%The epidemic process and dynamic analysis of plague in the natural plague focus of Alashan Citellus mongolicus umbratus

    Institute of Scientific and Technical Information of China (English)

    李兵; 王升文

    2011-01-01

    Objective To analyze the epidemic status of the natural plague focus of Alashan Citellus mongolicus umbratus, and to provide the basis for formulating the strategies of plague prevention and control. Methods According to the surveillance data of rodent, flea, Y. Pestis from 1999 to 2008, relationship between the constituent elements and the epidemic status quo in the plague foci of Alashan Citellus mongolicus umbratus was analyzed. Results There was no outbreaks of human plague epidemic in the Alashan Citellus mongolicus umbratus natural plague focus from 1999 to 2008. The number of host positive serums was 34, the maximum titer attain to 1: 2 560, the Alashan Citellus mongolicus umbratus density was 1. 50, the infected flea rate of body flea was 62.99% , the body flea index was 1. 96, the holes flea index was 0. 33 , the nest flea index was 5.1. Conclusions Animals plague had occurred in the part of plague focus of Alashan Citellus mongolicus umbratus from 1999 to 2004. From 2004 until now, the epidemic tendency of animals plague was inactively state, but Citellus mongolicus umbratus density and its flea index is much higher than the standards of plague control, it should be still attached great importance.%目的 探讨分析阿拉善黄鼠疫源地鼠疫流行现状,为今后制定防控对策提供依据.方法 通过归纳1999~ 2008年宿主、媒介、病原等监测数据,分析疫源地构成因素之间的相互关系与现状.结果 1999~2008年阿拉善黄鼠疫源地未发生人间鼠疫疫情;检出动物阳性血清34份,最高滴度1∶2560;阿拉善黄鼠密度1.50只/hm2,体蚤染蚤率为62.99%,体蚤指数为1.96,洞干蚤指数为0.33,巢蚤指数5.1.结论 1999~ 2004年阿拉善黄鼠鼠疫疫源地局部有动物鼠疫流行.从2004年截止目前,鼠疫动物流行病处于静息状态,但黄鼠密度和其蚤指数远高于鼠疫控制标准,仍然要高度重视鼠疫防控工作.

  16. Mutated and Bacteriophage T4 Nanoparticle Arrayed F1-V Immunogens from Yersinia pestis as Next Generation Plague Vaccines

    Science.gov (United States)

    Tao, Pan; Mahalingam, Marthandan; Kirtley, Michelle L.; van Lier, Christina J.; Sha, Jian; Yeager, Linsey A.; Chopra, Ashok K.; Rao, Venigalla B.

    2013-01-01

    Pneumonic plague is a highly virulent infectious disease with 100% mortality rate, and its causative organism Yersinia pestis poses a serious threat for deliberate use as a bioterror agent. Currently, there is no FDA approved vaccine against plague. The polymeric bacterial capsular protein F1, a key component of the currently tested bivalent subunit vaccine consisting, in addition, of low calcium response V antigen, has high propensity to aggregate, thus affecting its purification and vaccine efficacy. We used two basic approaches, structure-based immunogen design and phage T4 nanoparticle delivery, to construct new plague vaccines that provided complete protection against pneumonic plague. The NH2-terminal β-strand of F1 was transplanted to the COOH-terminus and the sequence flanking the β-strand was duplicated to eliminate polymerization but to retain the T cell epitopes. The mutated F1 was fused to the V antigen, a key virulence factor that forms the tip of the type three secretion system (T3SS). The F1mut-V protein showed a dramatic switch in solubility, producing a completely soluble monomer. The F1mut-V was then arrayed on phage T4 nanoparticle via the small outer capsid protein, Soc. The F1mut-V monomer was robustly immunogenic and the T4-decorated F1mut-V without any adjuvant induced balanced TH1 and TH2 responses in mice. Inclusion of an oligomerization-deficient YscF, another component of the T3SS, showed a slight enhancement in the potency of F1-V vaccine, while deletion of the putative immunomodulatory sequence of the V antigen did not improve the vaccine efficacy. Both the soluble (purified F1mut-V mixed with alhydrogel) and T4 decorated F1mut-V (no adjuvant) provided 100% protection to mice and rats against pneumonic plague evoked by high doses of Y. pestis CO92. These novel platforms might lead to efficacious and easily manufacturable next generation plague vaccines. PMID:23853602

  17. The search for early markers of plague: evidence for accumulation of soluble Yersinia pestis LcrV in bubonic and pneumonic mouse models of disease.

    Science.gov (United States)

    Flashner, Yehuda; Fisher, Morly; Tidhar, Avital; Mechaly, Adva; Gur, David; Halperin, Gideon; Zahavy, Eran; Mamroud, Emanuelle; Cohen, Sara

    2010-07-01

    Markers of the early stages of plague, a rapidly progressing deadly disease, are crucial for enabling the onset of an effective treatment. Here, we show that V-antigen protein (LcrV) is accumulated in the serum of Yersinia pestis-infected mice before bacterial colonization of the spleen and dissemination to blood, in a model of bubonic plague. LcrV accumulation is detected earlier than that of F1 capsular antigen, an established marker of disease. In a mouse model of pneumonic plague, LcrV can be determined in the bronchoalveolar lavage fluid somewhat later than F1, but before dissemination of Y. pestis to the blood. Thus, determination of soluble LcrV is suggested as a potential useful tool for monitoring disease progression in both bubonic and pneumonic plague. Moreover, it may be of particular advantage in cases of infections with F1 nonproducing strains.

  18. Misidentification of Yersinia pestis by automated systems, resulting in delayed diagnoses of human plague infections--Oregon and New Mexico, 2010-2011.

    Science.gov (United States)

    Tourdjman, Mathieu; Ibraheem, Mam; Brett, Meghan; Debess, Emilio; Progulske, Barbara; Ettestad, Paul; McGivern, Teresa; Petersen, Jeannine; Mead, Paul

    2012-10-01

    One human plague case was reported in Oregon in September 2010 and another in New Mexico in May 2011. Misidentification of Yersinia pestis by automated identification systems contributed to delayed diagnoses for both cases.

  19. Globalism of Outbreak and Prevalence of Cattle Plague(Rinderpest) around Byengjahoran (1636-1638).

    Science.gov (United States)

    Kim, Dong Jin; Yoo, Han Sang

    2013-04-01

    This study reviewed the outbreak and prevalence of cattle plague around Byeongjahoran from the perspective of international war in East Asia. First of all, the epidemiological characteristics of cattle plague in Manchuria where the outbreak of cattle plague was first reported around Byeongjahoran were analyzed. From the study, it was found the military activities that Sarhu (Qing) had made during the growth into Empire promoted the exchanges of various germs which became naturalized in the regions in Northeast Asia, and that such extreme situation as war made various diseases taken place and dispersed. In particular, because of military activities of Sarhu (Qing), various contagious diseases including smallpox which was prevalent in Inner-Mongolia and Shanxi became prevalent in Manchuria. During the contacts with Chosun after Jeongmyohoran, pathogen occurring Rinderpest was introduced into Manchuria. Favorable conditions for the interactions with various pathogens were provided by frequent contacts with wild animals through hunting and various cultivation groups composed of Manchurians, Mongolians, Han-Chinese and Chosun people. Rinderpest breaking in Chosun around Byeongjahoran was originated in Shenyang in 1636. It was transmitted to cattle in the Korean Peninsula and expanded to Kansai Region. At that time Rinderpest occurred and rapidly expanded in a specific area due to the interactions of pathogens, hosts and environments, and suddenly disappeared because of the extinction and the separation of hosts. It is consistent with the symptoms of modern times 'Rinderpest.' In Chosun it occurred in Pyeongan-do 4 months before the outbreak of Byeongjahoran and gave great damage on the capital area and northern Gyeonggi region. Because of the large scale migration of militaries after Byeongjahoran, Rindpest was expanded to Hasamdo and was terminated in February to April leaving big damages. The damages of Byeongjahoran were very severe. From the statistical records, it

  20. Evaluation of protective potential of Yersinia pestis outer membrane protein antigens as possible candidates for a new-generation recombinant plague vaccine.

    Science.gov (United States)

    Erova, Tatiana E; Rosenzweig, Jason A; Sha, Jian; Suarez, Giovanni; Sierra, Johanna C; Kirtley, Michelle L; van Lier, Christina J; Telepnev, Maxim V; Motin, Vladimir L; Chopra, Ashok K

    2013-02-01

    Plague caused by Yersinia pestis manifests itself in bubonic, septicemic, and pneumonic forms. Although the U.S. Food and Drug Administration recently approved levofloxacin, there is no approved human vaccine against plague. The capsular antigen F1 and the low-calcium-response V antigen (LcrV) of Y. pestis represent excellent vaccine candidates; however, the inability of the immune responses to F1 and LcrV to provide protection against Y. pestis F1(-) strains or those which harbor variants of LcrV is a significant concern. Here, we show that the passive transfer of hyperimmune sera from rats infected with the plague bacterium and rescued by levofloxacin protected naive animals against pneumonic plague. Furthermore, 10 to 12 protein bands from wild-type (WT) Y. pestis CO92 reacted with the aforementioned hyperimmune sera upon Western blot analysis. Based on mass spectrometric analysis, four of these proteins were identified as attachment invasion locus (Ail/OmpX), plasminogen-activating protease (Pla), outer membrane protein A (OmpA), and F1. The genes encoding these proteins were cloned, and the recombinant proteins purified from Escherichia coli for immunization purposes before challenging mice and rats with either the F1(-) mutant or WT CO92 in bubonic and pneumonic plague models. Although antibodies to Ail and OmpA protected mice against bubonic plague when challenged with the F1(-) CO92 strain, Pla antibodies were protective against pneumonic plague. In the rat model, antibodies to Ail provided protection only against pneumonic plague after WT CO92 challenge. Together, the addition of Y. pestis outer membrane proteins to a new-generation recombinant vaccine could provide protection against a wide variety of Y. pestis strains.

  1. Evaluation of Protective Potential of Yersinia pestis Outer Membrane Protein Antigens as Possible Candidates for a New-Generation Recombinant Plague Vaccine

    Science.gov (United States)

    Erova, Tatiana E.; Rosenzweig, Jason A.; Sha, Jian; Suarez, Giovanni; Sierra, Johanna C.; Kirtley, Michelle L.; van Lier, Christina J.; Telepnev, Maxim V.; Motin, Vladimir L.

    2013-01-01

    Plague caused by Yersinia pestis manifests itself in bubonic, septicemic, and pneumonic forms. Although the U.S. Food and Drug Administration recently approved levofloxacin, there is no approved human vaccine against plague. The capsular antigen F1 and the low-calcium-response V antigen (LcrV) of Y. pestis represent excellent vaccine candidates; however, the inability of the immune responses to F1 and LcrV to provide protection against Y. pestis F1− strains or those which harbor variants of LcrV is a significant concern. Here, we show that the passive transfer of hyperimmune sera from rats infected with the plague bacterium and rescued by levofloxacin protected naive animals against pneumonic plague. Furthermore, 10 to 12 protein bands from wild-type (WT) Y. pestis CO92 reacted with the aforementioned hyperimmune sera upon Western blot analysis. Based on mass spectrometric analysis, four of these proteins were identified as attachment invasion locus (Ail/OmpX), plasminogen-activating protease (Pla), outer membrane protein A (OmpA), and F1. The genes encoding these proteins were cloned, and the recombinant proteins purified from Escherichia coli for immunization purposes before challenging mice and rats with either the F1− mutant or WT CO92 in bubonic and pneumonic plague models. Although antibodies to Ail and OmpA protected mice against bubonic plague when challenged with the F1− CO92 strain, Pla antibodies were protective against pneumonic plague. In the rat model, antibodies to Ail provided protection only against pneumonic plague after WT CO92 challenge. Together, the addition of Y. pestis outer membrane proteins to a new-generation recombinant vaccine could provide protection against a wide variety of Y. pestis strains. PMID:23239803

  2. Predictors for Abundance of Host Flea and Floor Flea in Households of Villages with Endemic Commensal Rodent Plague, Yunnan Province, China

    OpenAIRE

    Jia-Xiang Yin; Alan Geater; Virasakdi Chongsuvivatwong; Xing-Qi Dong; Chun-Hong Du; You-Hong Zhong

    2011-01-01

    BACKGROUND: From 1990 to 2006, fifty-five natural villages experienced at least one plague epidemic in Lianghe County, Yunnan Province, China. This study is aimed to document flea abundance and identify predictors in households of villages with endemic commensal rodent plague in Lianghe County. METHODS: Trappings were used to collect fleas and interviews were conducted to gather demography, environmental factors, and other relevant information. Multivariate hurdle negative binomial model was ...

  3. Blood meal identification in off-host cat fleas (Ctenocephalides felis) from a plague-endemic region of Uganda.

    Science.gov (United States)

    Graham, Christine B; Borchert, Jeff N; Black, William C; Atiku, Linda A; Mpanga, Joseph T; Boegler, Karen A; Moore, Sean M; Gage, Kenneth L; Eisen, Rebecca J

    2013-02-01

    The cat flea, Ctenocephalides felis, is an inefficient vector of the plague bacterium (Yersinia pestis) and is the predominant off-host flea species in human habitations in the West Nile region, an established plague focus in northwest Uganda. To determine if C. felis might serve as a Y. pestis bridging vector in the West Nile region, we collected on- and off-host fleas from human habitations and used a real-time polymerase chain reaction-based assay to estimate the proportion of off-host C. felis that had fed on humans and the proportion that had fed on potentially infectious rodents or shrews. Our findings indicate that cat fleas in human habitations in the West Nile region feed primarily on domesticated species. We conclude that C. felis is unlikely to serve as a Y. pestis bridging vector in this region.

  4. A seasonal SIR metapopulation model with an Allee effect with application to controlling plague in prairie dog colonies.

    Science.gov (United States)

    Ekanayake, A J; Ekanayake, D B

    2015-01-01

    For wildlife species living among patchy habitats, disease and the Allee effect (reduced per capita birth rates at low population densities) may together drive a patch's population to extinction, particularly if births are seasonal. Yet local extinction may not be indicative of global extinction, and a patch may become recolonized by migrating individuals. We introduce deterministic and stochastic susceptible, infectious, and immune epidemic models with vector species to study disease in a metapopulation with an Allee effect and seasonal birth and dispersal. We obtain conditions for the existence of a strong Allee effect and existence and stability of a disease-free positive periodic solution. These general models have application to many wildlife diseases. As a case study, we apply them to evaluate dynamics of the sylvatic plague in prairie dog colonies interconnected through dispersal. We further evaluate the effects of control of the vector population and control by immunization on plague eradication.

  5. Nursing Care Given to the Plague Infected Patients in the Hospital General of Madrid (Spain in the 17th Century.

    Directory of Open Access Journals (Sweden)

    Manuel Jesús García Martínez

    2016-12-01

    Full Text Available This study reveals the work developed by the nurses of the Hospital general of Madrid (Spain in the treatment of the plague, and the training they received for their welfare tasks in the 17th century. Since the end of the 16th century, nurses knew and implemented a set of techniques and medicines to alleviate the terrible disease of the plague and, despite the scarce knowledge about the disease existing at the time, they sought to prevent the contagion with hygienic and dietary measures, and physical isolation. This study shows through which actions and in which conditions nurses worked to deal with such a terrible disease. All this helps to get a full knowledge of the development of the work done by nurses in the last five centuries and, therefore, to determine the evolution and shaping of the nursing profession in our country.

  6. [Macro- and microevolution as related to the problem of origin and global expansion of the plague pathogen Yersinia pestis].

    Science.gov (United States)

    Suntsov, V V; Suntsova, N I

    2008-01-01

    The ratio of macro- and microevolutionary processes is considered with reference to the ecological scenario of the origin of the plague pathogen and its subsequent natural and anthropogenic global expansion. The macroevolutionary transformation of the ancestral pseudotuberculosis microbe clone into the initial plague microbe Yersinia pestis tarbagani occurred in Central Asia at the end of the Late Pleistocene by a "vertical" Darwinian way in an inadaptive heterothermal continual intermediate environment--the Mongolian marmot Marmota sibirica-flea Oropsylla silantiewi system--via a sequence of unstable and currently extinct intermediate forms. Its natural geographic expansion on the "oil spot" principle in the postglacial time led to the microevolutionary formation of 20-30 hostal subspecies circulating in populations of the background species of burrowing rodents and pikas in arid areas of Eurasia. The intercontinental spread of the "marmot" and "rat" pathogen subspecies in the past few centuries has been exclusively anthropogenic, with the involvement of synanthropic (ship) rats.

  7. White plague-like coral disease in remote reefs of the Western Caribbean

    Directory of Open Access Journals (Sweden)

    Juan A Sánchez

    2010-05-01

    Full Text Available The health of coral reef communities has been decreasing over the last 50 years, due the negative effects of human activities combined with other natural processes. We present documentation of a White Plague Disease (WPD outbreak in the Serrana Bank, an isolated Western Caribbean atoll with presumably inexistent pollutant inputs from local human settlements. In addition, this study summarizes seven years of observations on diseased corals in the nearby island of San Andrés, which in contrast is one of the most populated islands of the Caribbean. There was a massive coral mortality in the atoll lagoon (14°27’53.24", 80°14’22.27" W, and 12m depth due to WPD on May 4 of 2003. Seventeen species were found dead or largely affected by the disease. The information resulting from GPS and manta-tow transects revealed that approximately 5.8ha of reticulate Montastraea spp. patch reefs were lethally affected by the disease in the atoll. On May 8 of the same year we observed and calculated a mean coral cover of 7.03% (SD± 2.44, a mean diseased coral tissue cover of 5.5% (SD± 1.1 and a 13.4% (SD± 8.05 of recently dead coral covered with a thin filamentous algae layer; approximately 73% of mortalities caused by the disease occurred before the end of the outbreak. A rough estimate of 18.9% in recent coral cover reduction can be attributed to WPD. This represents about 82% of the total coral cover decline since 1995. Semi-enclosed environments such as atoll lagoons and the reticulate patch-reefs of Montastraea spp. seem to be particularly vulnerable to this kind of coral disease, which constitute an alert to increase the monitoring of the same kind of atoll environments. The WPD has been present in the area of the nearby island of San Andrés at a low prevalence level, with sporadic increasing peaks of disease proliferation. The peaks observed during 1999 and 2004 comprised increases of 266% and 355% respectively, suggesting an alarming progression of

  8. Validation of Inverse Seasonal Peak Mortality in Medieval Plagues, Including the Black Death, in Comparison to Modern Yersinia pestis-Variant Diseases

    Science.gov (United States)

    Welford, Mark R.; Bossak, Brian H.

    2009-01-01

    Background Recent studies have noted myriad qualitative and quantitative inconsistencies between the medieval Black Death (and subsequent “plagues”) and modern empirical Y. pestis plague data, most of which is derived from the Indian and Chinese plague outbreaks of A.D. 1900±15 years. Previous works have noted apparent differences in seasonal mortality peaks during Black Death outbreaks versus peaks of bubonic and pneumonic plagues attributed to Y. pestis infection, but have not provided spatiotemporal statistical support. Our objective here was to validate individual observations of this seasonal discrepancy in peak mortality between historical epidemics and modern empirical data. Methodology/Principal Findings We compiled and aggregated multiple daily, weekly and monthly datasets of both Y. pestis plague epidemics and suspected Black Death epidemics to compare seasonal differences in mortality peaks at a monthly resolution. Statistical and time series analyses of the epidemic data indicate that a seasonal inversion in peak mortality does exist between known Y. pestis plague and suspected Black Death epidemics. We provide possible explanations for this seasonal inversion. Conclusions/Significance These results add further evidence of inconsistency between historical plagues, including the Black Death, and our current understanding of Y. pestis-variant disease. We expect that the line of inquiry into the disputed cause of the greatest recorded epidemic will continue to intensify. Given the rapid pace of environmental change in the modern world, it is crucial that we understand past lethal outbreaks as fully as possible in order to prepare for future deadly pandemics. PMID:20027294

  9. 宋代两浙路蝗灾及政府应对措施%Locust Plagues and Countermeasures in the Song Dynasty

    Institute of Scientific and Technical Information of China (English)

    金城

    2016-01-01

    蝗灾是我国农业历史上的三大自然灾害之一,因其危害巨大而受到历代统治者的关注。宋代蝗灾频发,宋廷对蝗灾十分重视。文章考察了宋代两浙路蝗灾概况,从蝗灾灾情、特点及政府应对措施等方面对宋代蝗灾进行阐述,并对宋廷治蝗措施的利弊进行评价。%The plagues of locusts are one of the three natural disasters in the agricultural history of our country, whose huge harm was observed by the past rulers. As there were frequent plagues of locusts in the Song dynasty, the royal court attached great importance to them. This paper studies the general situation of the Liangzhe area locust plagues, elaborates on the plagues from their character-istics and the imperial court’ s measures to deal with the plagues in the Song dynasty, and finally evaluates the pros and cons of the measures against the plagues taken by the royal court.

  10. Current status and prospects of research on new plague vaccines%新型鼠疫疫苗研究现状及展望(续)

    Institute of Scientific and Technical Information of China (English)

    焦磊

    2011-01-01

    As current available attenuated plague vaccine for human has some disadvantages in terms of product consistency,inoculating convenience,adverse reactions and protection against pneumonic plague,new plague vaccine research is promoted.In this review,potential candidate antigens for plague vaccines and immiunity against plague,as well as current status,obstacles and prospocts of new plague vaccine research are discussed.%现行人用鼠疫活疫苗在产品的一致性、易操作性、不良反应以及对肺鼠疫的预防等方面均存在不足,这就促进了新型鼠疫疫苗的研究.此文从鼠疫疫苗潜在候选抗原、抗鼠疫免疫及新型鼠疫疫苗研究现状、障碍和展望等方面进行综述.

  11. T cells play an essential role in anti-F1 mediated rapid protection against bubonic plague.

    Science.gov (United States)

    Levy, Yinon; Flashner, Yehuda; Tidhar, Avital; Zauberman, Ayelet; Aftalion, Moshe; Lazar, Shirley; Gur, David; Shafferman, Avigdor; Mamroud, Emanuelle

    2011-09-16

    Plague, which is initiated by Yersinia pestis infection, is a fatal disease that progresses rapidly and leads to high mortality rates if not treated. Antibiotics are an effective plague therapy, but antibiotic-resistant Y. pestis strains have been reported and therefore alternative countermeasures are needed. In the present study, we assessed the potential of an F1 plus LcrV-based vaccine to provide protection shortly pre- or post-exposure to a lethal Y. pestis infection. Mice vaccinated up to one day before or even several hours after subcutaneous challenge were effectively protected. Mice immunized one or three days pre-challenge were protected even though their anti-F1 and anti-LcrV titers were below detection levels at the day of challenge. Moreover, using B-cell deficient μMT mice, we found that rapidly induced protective immunity requires the integrity of the humoral immune system. Analysis of the individual contributions of vaccine components to protection revealed that rF1 is responsible for the observed rapid antibody-mediated immunity. Applying anti-F1 passive therapy in the mouse model of bubonic plague demonstrated that anti-F1 F(ab')(2) can delay mortality, but it cannot provide long-lasting protection, as do intact anti-F1 molecules. Fc-dependent immune components, such as the complement system and (to a lesser extent) neutrophils, were found to contribute to mouse survival. Interestingly, T cells but not B cells were found to be essential for the recovery of infected animals following passive anti-F1 mediated therapy. These data extend our understanding of the immune mechanisms required for the development of a rapid and effective post-exposure therapy against plague. Copyright © 2011 Elsevier Ltd. All rights reserved.

  12. Roles of chaperone/usher pathways of Yersinia pestis in a murine model of plague and adhesion to host cells.

    Science.gov (United States)

    Hatkoff, Matthew; Runco, Lisa M; Pujol, Celine; Jayatilaka, Indralatha; Furie, Martha B; Bliska, James B; Thanassi, David G

    2012-10-01

    Yersinia pestis and many other Gram-negative pathogenic bacteria use the chaperone/usher (CU) pathway to assemble virulence-associated surface fibers termed pili or fimbriae. Y. pestis has two well-characterized CU pathways: the caf genes coding for the F1 capsule and the psa genes coding for the pH 6 antigen. The Y. pestis genome contains additional CU pathways that are capable of assembling pilus fibers, but the roles of these pathways in the pathogenesis of plague are not understood. We constructed deletion mutations in the usher genes for six of the additional Y. pestis CU pathways. The wild-type (WT) and usher deletion strains were compared in the murine bubonic (subcutaneous) and pneumonic (intranasal) plague infection models. Y. pestis strains containing deletions in CU pathways y0348-0352, y1858-1862, and y1869-1873 were attenuated for virulence compared to the WT strain by the intranasal, but not subcutaneous, routes of infection, suggesting specific roles for these pathways during pneumonic plague. We examined binding of the Y. pestis WT and usher deletion strains to A549 human lung epithelial cells, HEp-2 human cervical epithelial cells, and primary human and murine macrophages. Y. pestis CU pathways y0348-0352 and y1858-1862 were found to contribute to adhesion to all host cells tested, whereas pathway y1869-1873 was specific for binding to macrophages. The correlation between the virulence attenuation and host cell binding phenotypes of the usher deletion mutants identifies three of the additional CU pathways of Y. pestis as mediating interactions with host cells that are important for the pathogenesis of plague.

  13. The Yfe and Feo transporters are involved in microaerobic growth and virulence of Yersinia pestis in bubonic plague.

    Science.gov (United States)

    Fetherston, Jacqueline D; Mier, Ildefonso; Truszczynska, Helena; Perry, Robert D

    2012-11-01

    The Yfe/Sit and Feo transport systems are important for the growth of a variety of bacteria. In Yersinia pestis, single mutations in either yfe or feo result in reduced growth under static (limited aeration), iron-chelated conditions, while a yfe feo double mutant has a more severe growth defect. These growth defects were not observed when bacteria were grown under aerobic conditions or in strains capable of producing the siderophore yersiniabactin (Ybt) and the putative ferrous transporter FetMP. Both fetP and a downstream locus (flp for fet linked phenotype) were required for growth of a yfe feo ybt mutant under static, iron-limiting conditions. An feoB mutation alone had no effect on the virulence of Y. pestis in either bubonic or pneumonic plague models. An feo yfe double mutant was still fully virulent in a pneumonic plague model but had an ∼90-fold increase in the 50% lethal dose (LD(50)) relative to the Yfe(+) Feo(+) parent strain in a bubonic plague model. Thus, Yfe and Feo, in addition to Ybt, play an important role in the progression of bubonic plague. Finally, we examined the factors affecting the expression of the feo operon in Y. pestis. Under static growth conditions, the Y. pestis feo::lacZ fusion was repressed by iron in a Fur-dependent manner but not in cells grown aerobically. Mutations in feoC, fnr, arcA, oxyR, or rstAB had no significant effect on transcription of the Y. pestis feo promoter. Thus, the factor(s) that prevents repression by Fur under aerobic growth conditions remains to be identified.

  14. Absence of Yersinia pestis-specific DNA in human teeth from five European excavations of putative plague victims.

    Science.gov (United States)

    Gilbert, M Thomas P; Cuccui, Jon; White, William; Lynnerup, Niels; Titball, Richard W; Cooper, Alan; Prentice, Michael B

    2004-02-01

    This study reports the results of a collaborative study undertaken by two independent research groups to (a) confirm recent PCR-based detection of Yersinia pestis DNA in human teeth from medieval plague victims in France, and (b) to extend these observations over five different European burial sites believed to contain plague victims dating from the late 13th to 17th centuries. Several different sets of primers were used, including those previously documented to yield positive results on ancient DNA extracts. No Y. pestis DNA could be amplified from DNA extracted from 108 teeth belonging to 61 individuals, despite the amplification of numerous other bacterial DNA sequences. Several methods of extracting dentine prior to the DNA extraction were also compared. PCR for bacterial 16S rDNA indicated the presence of multiple bacterial species in 23 out of 27 teeth DNA extracts where dentine was extracted using previously described methods. In comparison, positive results were obtained from only five out of 44 teeth DNA extracts for which a novel contamination-minimizing embedding technique was used. Therefore, high levels of environmental bacterial DNA are present in DNA extracts where previously described methods of tooth manipulation are used. To conclude, the absence of Y. pestis-specific DNA in an exhaustive search using specimens from multiple putative European plague burial sites does not allow us to confirm the identification of Y. pestis as the aetiological agent of the Black Death and subsequent plagues. In addition, the utility of the published tooth-based ancient DNA technique used to diagnose fatal bacteraemias in historical epidemics still awaits independent corroboration.

  15. A chaotic model for the plague epidemic that has occurred in Bombay at the end of the 19th century

    Science.gov (United States)

    Mangiarotti, Sylvain

    2015-04-01

    The plague epidemic that has occurred in Bombay at the end of the 19th century was detected in 1896. One year before, an Advisory Committee had been appointed by the Secretary of State for India, the Royal Society, and the Lister Institute. This Committee made numerous investigations and gathered a large panel of data including the number of people attacked and died from the plague, records of rat and flea populations, as well as meteorological records of temperature and humidity [1]. The global modeling technique [2] aims to obtain low dimensional models able to simulate the observed cycles from time series. As far as we know, this technique has been tried only to one case of epidemiological analysis (the whooping cough infection) based on a discrete formulation [3]. In the present work, the continuous time formulation of this technique is used to analyze the time evolution of the plague epidemic from this data set. One low dimensional model (three variables) is obtained exhibiting a limit cycle of period-5. A chaotic behavior could be derived from this model by tuning the model parameters. It provides a strong argument for a dynamical behavior that can be approximated by low dimensional deterministic equations. This model also provides an empirical argument for chaos in epidemics. [1] Verjbitski D. T., Bannerman W. B. & Kápadiâ R. T., 1908. Reports on Plague Investigations in India (May,1908), The Journal of Hygiene, 8(2), 161 -308. [2] Mangiarotti S., Coudret R., Drapeau L. & Jarlan L., 2012. Polynomial search and Global modelling: two algorithms for modeling chaos. Physical Review E, 86(4), 046205. [3] Boudjema G. & Cazelles B., 2003. Extraction of nonlinear dynamics from short and noisy time series. Chaos, Solitons and Fractals, 12, 2051-2069.

  16. Cethromycin-mediated protection against the plague pathogen Yersinia pestis in a rat model of infection and comparison with levofloxacin.

    Science.gov (United States)

    Rosenzweig, Jason A; Brackman, Sheri M; Kirtley, Michelle L; Sha, Jian; Erova, Tatiana E; Yeager, Linsey A; Peterson, Johnny W; Xu, Ze-Qi; Chopra, Ashok K

    2011-11-01

    The Gram-negative plague bacterium, Yersinia pestis, has historically been regarded as one of the deadliest pathogens known to mankind, having caused three major pandemics. After being transmitted by the bite of an infected flea arthropod vector, Y. pestis can cause three forms of human plague: bubonic, septicemic, and pneumonic, with the latter two having very high mortality rates. With increased threats of bioterrorism, it is likely that a multidrug-resistant Y. pestis strain would be employed, and, as such, conventional antibiotics typically used to treat Y. pestis (e.g., streptomycin, tetracycline, and gentamicin) would be ineffective. In this study, cethromycin (a ketolide antibiotic which inhibits bacterial protein synthesis and is currently in clinical trials for respiratory tract infections) was evaluated for antiplague activity in a rat model of pneumonic infection and compared with levofloxacin, which operates via inhibition of bacterial topoisomerase and DNA gyrase. Following a respiratory challenge of 24 to 30 times the 50% lethal dose of the highly virulent Y. pestis CO92 strain, 70 mg of cethromycin per kg of body weight (orally administered twice daily 24 h postinfection for a period of 7 days) provided complete protection to animals against mortality without any toxic effects. Further, no detectable plague bacilli were cultured from infected animals' blood and spleens following cethromycin treatment. The antibiotic was most effective when administered to rats 24 h postinfection, as the animals succumbed to infection if treatment was further delayed. All cethromycin-treated survivors tolerated 2 subsequent exposures to even higher lethal Y. pestis doses without further antibiotic treatment, which was related, in part, to the development of specific antibodies to the capsular and low-calcium-response V antigens of Y. pestis. These data demonstrate that cethromycin is a potent antiplague drug that can be used to treat pneumonic plague.

  17. A Bivalent Anthrax–Plague Vaccine That Can Protect against Two Tier-1 Bioterror Pathogens, Bacillus anthracis and Yersinia pestis

    OpenAIRE

    Pan Tao; Marthandan Mahalingam; Jingen Zhu; Mahtab Moayeri; Kirtley, Michelle L.; Fitts, Eric C.; Andersson, Jourdan A.; Lawrence, William S.; Leppla, Stephen H.; Chopra, Ashok K.; Rao, Venigalla B.

    2017-01-01

    Bioterrorism remains as one of the biggest challenges to global security and public health. Since the deadly anthrax attacks of 2001 in the United States, Bacillus anthracis and Yersinia pestis, the causative agents of anthrax and plague, respectively, gained notoriety and were listed by the CDC as Tier-1 biothreat agents. Currently, there is no Food and Drug Administration-approved vaccine against either of these threats for mass vaccination to protect general public, let alone a bivalent va...

  18. Roles of Chaperone/Usher Pathways of Yersinia pestis in a Murine Model of Plague and Adhesion to Host Cells

    Science.gov (United States)

    Hatkoff, Matthew; Runco, Lisa M.; Pujol, Celine; Jayatilaka, Indralatha; Furie, Martha B.; Bliska, James B.

    2012-01-01

    Yersinia pestis and many other Gram-negative pathogenic bacteria use the chaperone/usher (CU) pathway to assemble virulence-associated surface fibers termed pili or fimbriae. Y. pestis has two well-characterized CU pathways: the caf genes coding for the F1 capsule and the psa genes coding for the pH 6 antigen. The Y. pestis genome contains additional CU pathways that are capable of assembling pilus fibers, but the roles of these pathways in the pathogenesis of plague are not understood. We constructed deletion mutations in the usher genes for six of the additional Y. pestis CU pathways. The wild-type (WT) and usher deletion strains were compared in the murine bubonic (subcutaneous) and pneumonic (intranasal) plague infection models. Y. pestis strains containing deletions in CU pathways y0348-0352, y1858-1862, and y1869-1873 were attenuated for virulence compared to the WT strain by the intranasal, but not subcutaneous, routes of infection, suggesting specific roles for these pathways during pneumonic plague. We examined binding of the Y. pestis WT and usher deletion strains to A549 human lung epithelial cells, HEp-2 human cervical epithelial cells, and primary human and murine macrophages. Y. pestis CU pathways y0348-0352 and y1858-1862 were found to contribute to adhesion to all host cells tested, whereas pathway y1869-1873 was specific for binding to macrophages. The correlation between the virulence attenuation and host cell binding phenotypes of the usher deletion mutants identifies three of the additional CU pathways of Y. pestis as mediating interactions with host cells that are important for the pathogenesis of plague. PMID:22851745

  19. Predicting small mammal and flea abundance using landform and soil properties in a plague endemic area in Lushoto District, Tanzania.

    Science.gov (United States)

    Meliyo, Joel L; Kimaro, Didas N; Msanya, Balthazar M; Mulungu, Loth S; Hieronimo, Proches; Kihupi, Nganga I; Gulinck, Hubert; Deckers, Jozef A

    2014-07-01

    Small mammals particularly rodents, are considered the primary natural hosts of plague. Literature suggests that plague persistence in natural foci has a root cause in soils. The objective of this study was to investigate the relationship between on the one hand landforms and associated soil properties, and on the other hand small mammals and fleas in West Usambara Mountains in Tanzania, a plague endemic area. Standard field survey methods coupled with Geographical Information System (GIS) technique were used to examine landform and soils characteristics. Soil samples were analysed in the laboratory for physico-chemical properties. Small mammals were trapped on pre-established landform positions and identified to genus/species level. Fleas were removed from the trapped small mammals and counted. Exploration of landform and soil data was done using ArcGIS Toolbox functions and descriptive statistical analysis. The relationships between landforms, soils, small mammals and fleas were established by generalised linear regression model (GLM) operated in R statistics software. Results show that landforms and soils influence the abundance of small mammals and fleas and their spatial distribution. The abundance of small mammals and fleas increased with increase in elevation. Small mammal species richness also increases with elevation. A landform-soil model shows that available phosphorus, slope aspect and elevation were statistically significant predictors explaining richness and abundance of small mammals. Fleas' abundance and spatial distribution were influenced by hill-shade, available phosphorus and base saturation. The study suggests that landforms and soils have a strong influence on the richness and evenness of small mammals and their fleas' abundance hence could be used to explain plague dynamics in the area.

  20. The NlpD lipoprotein is a novel Yersinia pestis virulence factor essential for the development of plague.

    Directory of Open Access Journals (Sweden)

    Avital Tidhar

    Full Text Available Yersinia pestis is the causative agent of plague. Previously we have isolated an attenuated Y. pestis transposon insertion mutant in which the pcm gene was disrupted. In the present study, we investigated the expression and the role of pcm locus genes in Y. pestis pathogenesis using a set of isogenic surE, pcm, nlpD and rpoS mutants of the fully virulent Kimberley53 strain. We show that in Y. pestis, nlpD expression is controlled from elements residing within the upstream genes surE and pcm. The NlpD lipoprotein is the only factor encoded from the pcm locus that is essential for Y. pestis virulence. A chromosomal deletion of the nlpD gene sequence resulted in a drastic reduction in virulence to an LD(50 of at least 10(7 cfu for subcutaneous and airway routes of infection. The mutant was unable to colonize mouse organs following infection. The filamented morphology of the nlpD mutant indicates that NlpD is involved in cell separation; however, deletion of nlpD did not affect in vitro growth rate. Trans-complementation experiments with the Y. pestis nlpD gene restored virulence and all other phenotypic defects. Finally, we demonstrated that subcutaneous administration of the nlpD mutant could protect animals against bubonic and primary pneumonic plague. Taken together, these results demonstrate that Y. pestis NlpD is a novel virulence factor essential for the development of bubonic and pneumonic plague. Further, the nlpD mutant is superior to the EV76 prototype live vaccine strain in immunogenicity and in conferring effective protective immunity. Thus it could serve as a basis for a very potent live vaccine against bubonic and pneumonic plague.