A Large Plasmodium vivax Reservoir and Little Population Structure in the South Pacific

PLoS One. 2013 Jun 18;8(6):e66041. doi: 10.1371/journal.pone.0066041. Print 2013.

Abstract

Introduction: The importance of Plasmodium vivax in malaria elimination is increasingly being recognized, yet little is known about its population size and population genetic structure in the South Pacific, an area that is the focus of intensified malaria control.

Methods: We have genotyped 13 microsatellite markers in 295 P. vivax isolates from four geographically distinct sites in Papua New Guinea (PNG) and one site from Solomon Islands, representing different transmission intensities.

Results: Diversity was very high with expected heterozygosity values ranging from 0.62 to 0.98 for the different markers. Effective population size was high (12'872 to 19'533 per site). In PNG population structuring was limited with moderate levels of genetic differentiation. F ST values (adjusted for high diversity of markers) were 0.14-0.15. Slightly higher levels were observed between PNG populations and Solomon Islands (F ST = 0.16).

Conclusions: Low levels of population structure despite geographical barriers to transmission are in sharp contrast to results from regions of low P. vivax endemicity. Prior to intensification of malaria control programs in the study area, parasite diversity and effective population size remained high.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Disease Reservoirs*
  • Genes, Protozoan
  • Genetic Markers
  • Genotype
  • Humans
  • Malaria, Vivax / parasitology*
  • Melanesia / epidemiology
  • Microsatellite Repeats / genetics
  • Papua New Guinea / epidemiology
  • Plasmodium vivax / genetics
  • Plasmodium vivax / isolation & purification*
  • Polymerase Chain Reaction

Substances

  • Genetic Markers

Grant support

This work was supported by the Swiss National Science Foundation (www.snf.ch, grant numbers: 320030-125316/1, 310030-134889/1). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.