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Plague: past, present, and future.

Stenseth NC, Atshabar BB, Begon M, Belmain SR, Bertherat E, Carniel E, Gage KL, Leirs H, Rahalison L - PLoS Med. (2008)

View Article: PubMed Central - PubMed

Affiliation: Centre for Ecological and Evolutionary Synthesis, Department of Biology, University of Oslo, Oslo, Norway. n.c.stenseth@bio.uio.no

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Three recent international meetings on plague (Box 2) concluded that: (1) it should be re-emphasised that the plague bacillus (Yersinia pestis) still causes several thousand human cases per year (Figure 1); (2) locally perceived risks far outstrip the objective risk based purely on the number of cases ; (3) climate change might increase the risk of plague outbreaks where plague is currently endemic and new plague areas might arise ; (4) remarkably little is known about the dynamics of plague in its natural reservoirs and hence about changing risks for humans ; and, therefore, (5) plague should be taken much more seriously by the international community than appears to be the case... This divergence was characterised by the acquisition of a few genetic elements; more particularly, two plasmids that play a key role in flea-borne transmission... The exceptional pathogenicity of Y. pestis compared to the enteropathogenic species may be explained by its new mode of transmission... The first (“the Justinian plague”) spread around the Mediterranean Sea in the 6th century AD, the second (“the Black Death”) started in Europe in the 14th century and recurred intermittently for more than 300 years, and the third started in China during the middle of the 19th century and spread throughout the world... Purportedly, each pandemic was caused by a different biovar of Y. pestis, respectively, Antiqua (still found in Africa and Central Asia), Medievalis (currently limited to Central Asia), and Orientalis (almost worldwide in its distribution)... Plague is endemic in a variety of wildlife rodent species worldwide in a wide range of natural habitats, with commensal rats only sometimes playing a role as “liaison” hosts, carrying plague between the sylvatic reservoir and people... Human plague may be contracted from (1) being bitten by the fleas of wildlife rodent species in rural settings (e.g., in the south-western United States ) or of commensal rodents that move freely between villages and the forest habitats occupied by reservoir hosts (e.g., in Tanzania); rodents' movements have become more frequent as human activity has fragmented the forest ; (2) eating infected animals such as guinea pigs in Peru and Ecuador or camels that contract the disease from rodent fleas in Central Asia and the Middle East ; or (3) handling cats infected through the consumption of plague-infected rodents in Africa or the United States... There has been some recent progress, such as development of rapid diagnosis tools, some challenging of accepted dogma about the dynamics of sylvatic plague in the United States and in Central Asia, and the identification of predictive critical rodent abundance thresholds for plague in Kazakhstan... What is striking, though, is our lack of understanding of this high-profile disease in even the best-studied foci, particularly in Africa: often, we do not even know the natural reservoir of the bacilli... The capacity to undergo genomic rearrangements may thus be an efficient means for the plague bacillus to adapt to new ecological niches... Terrorist use of an aerosol released in a confined space could result in significant mortality and widespread panic, and no one would wish plague weaponisation knowledge and material to fall into terrorist hands... However, the need for scientifically sound studies on the dynamics of infection, transmission, outbreak management, and improved surveillance and monitoring systems has never been greater... But in our opinion, plague should not be relegated to the sidelines... It remains a poorly understood threat that we cannot afford to ignore. (303 KB PDF) Click here for additional data file. (356 KB PDF) Click here for additional data file.

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Possible Transmission Pathways for the Plague Agent, Y. pestisThese pathways include sylvatic rodent-flea cycles (A), the commensal rodent-flea cycles (B), and the pneumonic transmission in humans (C). The colour of the arrows indicates the mechanism (flea bites, air particles, meat consumption) through which the bacteria are transferred from one host to another. Dark blue arrows indicate ways in which plague can move to other areas.
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pmed-0050003-g002: Possible Transmission Pathways for the Plague Agent, Y. pestisThese pathways include sylvatic rodent-flea cycles (A), the commensal rodent-flea cycles (B), and the pneumonic transmission in humans (C). The colour of the arrows indicates the mechanism (flea bites, air particles, meat consumption) through which the bacteria are transferred from one host to another. Dark blue arrows indicate ways in which plague can move to other areas.

Mentions: The epidemiology of plague, however, is much more complicated than this urban-plague scenario suggests, involving several other—more likely—pathways of transmission (Box 3 and Figure 2). This complicated epidemiology necessitates a reconsideration of plague ecology.


Plague: past, present, and future.

Stenseth NC, Atshabar BB, Begon M, Belmain SR, Bertherat E, Carniel E, Gage KL, Leirs H, Rahalison L - PLoS Med. (2008)

Possible Transmission Pathways for the Plague Agent, Y. pestisThese pathways include sylvatic rodent-flea cycles (A), the commensal rodent-flea cycles (B), and the pneumonic transmission in humans (C). The colour of the arrows indicates the mechanism (flea bites, air particles, meat consumption) through which the bacteria are transferred from one host to another. Dark blue arrows indicate ways in which plague can move to other areas.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2194748&req=5

pmed-0050003-g002: Possible Transmission Pathways for the Plague Agent, Y. pestisThese pathways include sylvatic rodent-flea cycles (A), the commensal rodent-flea cycles (B), and the pneumonic transmission in humans (C). The colour of the arrows indicates the mechanism (flea bites, air particles, meat consumption) through which the bacteria are transferred from one host to another. Dark blue arrows indicate ways in which plague can move to other areas.
Mentions: The epidemiology of plague, however, is much more complicated than this urban-plague scenario suggests, involving several other—more likely—pathways of transmission (Box 3 and Figure 2). This complicated epidemiology necessitates a reconsideration of plague ecology.

View Article: PubMed Central - PubMed

Affiliation: Centre for Ecological and Evolutionary Synthesis, Department of Biology, University of Oslo, Oslo, Norway. n.c.stenseth@bio.uio.no

AUTOMATICALLY GENERATED EXCERPT
Please rate it.

Three recent international meetings on plague (Box 2) concluded that: (1) it should be re-emphasised that the plague bacillus (Yersinia pestis) still causes several thousand human cases per year (Figure 1); (2) locally perceived risks far outstrip the objective risk based purely on the number of cases ; (3) climate change might increase the risk of plague outbreaks where plague is currently endemic and new plague areas might arise ; (4) remarkably little is known about the dynamics of plague in its natural reservoirs and hence about changing risks for humans ; and, therefore, (5) plague should be taken much more seriously by the international community than appears to be the case... This divergence was characterised by the acquisition of a few genetic elements; more particularly, two plasmids that play a key role in flea-borne transmission... The exceptional pathogenicity of Y. pestis compared to the enteropathogenic species may be explained by its new mode of transmission... The first (“the Justinian plague”) spread around the Mediterranean Sea in the 6th century AD, the second (“the Black Death”) started in Europe in the 14th century and recurred intermittently for more than 300 years, and the third started in China during the middle of the 19th century and spread throughout the world... Purportedly, each pandemic was caused by a different biovar of Y. pestis, respectively, Antiqua (still found in Africa and Central Asia), Medievalis (currently limited to Central Asia), and Orientalis (almost worldwide in its distribution)... Plague is endemic in a variety of wildlife rodent species worldwide in a wide range of natural habitats, with commensal rats only sometimes playing a role as “liaison” hosts, carrying plague between the sylvatic reservoir and people... Human plague may be contracted from (1) being bitten by the fleas of wildlife rodent species in rural settings (e.g., in the south-western United States ) or of commensal rodents that move freely between villages and the forest habitats occupied by reservoir hosts (e.g., in Tanzania); rodents' movements have become more frequent as human activity has fragmented the forest ; (2) eating infected animals such as guinea pigs in Peru and Ecuador or camels that contract the disease from rodent fleas in Central Asia and the Middle East ; or (3) handling cats infected through the consumption of plague-infected rodents in Africa or the United States... There has been some recent progress, such as development of rapid diagnosis tools, some challenging of accepted dogma about the dynamics of sylvatic plague in the United States and in Central Asia, and the identification of predictive critical rodent abundance thresholds for plague in Kazakhstan... What is striking, though, is our lack of understanding of this high-profile disease in even the best-studied foci, particularly in Africa: often, we do not even know the natural reservoir of the bacilli... The capacity to undergo genomic rearrangements may thus be an efficient means for the plague bacillus to adapt to new ecological niches... Terrorist use of an aerosol released in a confined space could result in significant mortality and widespread panic, and no one would wish plague weaponisation knowledge and material to fall into terrorist hands... However, the need for scientifically sound studies on the dynamics of infection, transmission, outbreak management, and improved surveillance and monitoring systems has never been greater... But in our opinion, plague should not be relegated to the sidelines... It remains a poorly understood threat that we cannot afford to ignore. (303 KB PDF) Click here for additional data file. (356 KB PDF) Click here for additional data file.

Show MeSH
Related in: MedlinePlus