PLoS ONE (Jun 2010)

Heritability of the human infectious reservoir of malaria parasites.

  • Yaye Ramatoulaye Lawaly,
  • Anavaj Sakuntabhai,
  • Laurence Marrama,
  • Lassana Konate,
  • Waraphon Phimpraphi,
  • Cheikh Sokhna,
  • Adama Tall,
  • Fatoumata Diène Sarr,
  • Chayanon Peerapittayamongkol,
  • Chalisa Louicharoen,
  • Bradley S Schneider,
  • Anaïs Levescot,
  • Arthur Talman,
  • Isabelle Casademont,
  • Didier Menard,
  • Jean-François Trape,
  • Christophe Rogier,
  • Jaranit Kaewkunwal,
  • Thanyachai Sura,
  • Issarang Nuchprayoon,
  • Frederic Ariey,
  • Laurence Baril,
  • Pratap Singhasivanon,
  • Odile Mercereau-Puijalon,
  • Rick Paul

DOI
https://doi.org/10.1371/journal.pone.0011358
Journal volume & issue
Vol. 5, no. 6
p. e11358

Abstract

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BackgroundStudies on human genetic factors associated with malaria have hitherto concentrated on their role in susceptibility to and protection from disease. In contrast, virtually no attention has been paid to the role of human genetics in eliciting the production of parasite transmission stages, the gametocytes, and thus enhancing the spread of disease.Methods and findingsWe analysed four longitudinal family-based cohort studies from Senegal and Thailand followed for 2-8 years and evaluated the relative impact of the human genetic and non-genetic factors on gametocyte production in infections of Plasmodium falciparum or P. vivax. Prevalence and density of gametocyte carriage were evaluated in asymptomatic and symptomatic infections by examination of Giemsa-stained blood smears and/or RT-PCR (for falciparum in one site). A significant human genetic contribution was found to be associated with gametocyte prevalence in asymptomatic P. falciparum infections. By contrast, there was no heritability associated with the production of gametocytes for P. falciparum or P. vivax symptomatic infections. Sickle cell mutation, HbS, was associated with increased gametocyte prevalence but its contribution was small.ConclusionsThe existence of a significant human genetic contribution to gametocyte prevalence in asymptomatic infections suggests that candidate gene and genome wide association approaches may be usefully applied to explore the underlying human genetics. Prospective epidemiological studies will provide an opportunity to generate novel and perhaps more epidemiologically pertinent gametocyte data with which similar analyses can be performed and the role of human genetics in parasite transmission ascertained.