3 years ago

Temporal phylogeography of <i>Yersinia pestis</i> in Madagascar: Insights into the long-term maintenance of plague

Genevieve Andersen, Minoarisoa Rajerison, Roxanne Nottingham, Jason W. Sahl, David M. Wagner, Voahangy Andrianaivoarimanana, Crystal M. Hepp, Dawn N. Birdsell, Carina M. Hall, Paul Keim, Heather Centner, Sandra Telfer, Amy J. Vogler, Lila Rahalison

by Amy J. Vogler, Voahangy Andrianaivoarimanana, Sandra Telfer, Carina M. Hall, Jason W. Sahl, Crystal M. Hepp, Heather Centner, Genevieve Andersen, Dawn N. Birdsell, Lila Rahalison, Roxanne Nottingham, Paul Keim, David M. Wagner, Minoarisoa Rajerison

Background

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.

Methodology/Principal findings

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.

Conclusions/Significance

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 likelihood of observing human plague cases in a given year in a particular location.

Publisher URL: http://journals.plos.org/plosntds/article

DOI: 10.1371/journal.pntd.0005887

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.