Phylogeography and Molecular Epidemiology of Yersinia pestis in Madagascar
2011

Studying the Spread of Plague in Madagascar

Sample size: 262 publication 10 minutes Evidence: high

Author Information

Author(s): Amy J. Vogler, Fabien Chan, David M. Wagner, Philippe Roumagnac, Judy Lee, Roxanne Nera, Mark Eppinger, Jacques Ravel, Lila Rahalison, Bruno W. Rasoamanana, Stephen M. Beckstrom-Sternberg, Mark Achtman, Suzanne Chanteau, Paul Keim

Primary Institution: Northern Arizona University

Hypothesis

What are the geographic-genetic patterns of Yersinia pestis in Madagascar?

Conclusion

Yersinia pestis is maintained in multiple genetically distinct subpopulations in Madagascar, influenced by both natural cycles and human activity.

Supporting Evidence

  • Plague has been a significant health problem in Madagascar since its introduction in 1898.
  • Two major genetic groups of Y. pestis were identified, further divided into 15 subclades.
  • Geographic separation among subclades suggests limited gene flow and local cycling.
  • Human activity is likely responsible for long-distance transfers of Y. pestis.
  • High levels of VNTR diversity were found among the Malagasy isolates.

Takeaway

Plague in Madagascar is caused by a germ called Yersinia pestis, which lives in different groups in separate areas, and people help it spread.

Methodology

The study analyzed 262 Malagasy isolates using 56 SNPs and a 43-locus MLVA system to identify genetic groups and their geographic distribution.

Potential Biases

Potential bias in the genetic representation of older isolates due to limited sampling.

Limitations

The study may not capture all genetic diversity due to limited sampling from earlier years.

Participant Demographics

Isolates were collected from 25 districts in Madagascar, primarily from human cases.

Statistical Information

P-Value

p<0.0001

Statistical Significance

p<0.0001

Digital Object Identifier (DOI)

10.1371/journal.pntd.0001319

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