Frequent expansion of Plasmodium vivax Duffy Binding Protein in Ethiopia and its epidemiological significance

PLoS Negl Trop Dis. 2019 Sep 11;13(9):e0007222. doi: 10.1371/journal.pntd.0007222. eCollection 2019 Sep.


Plasmodium vivax invasion of human erythrocytes depends on the Duffy Binding Protein (PvDBP) which interacts with the Duffy antigen. PvDBP copy number has been recently shown to vary between P. vivax isolates in Sub-Saharan Africa. However, the extent of PvDBP copy number variation, the type of PvDBP multiplications, as well as its significance across broad samples are still unclear. We determined the prevalence and type of PvDBP duplications, as well as PvDBP copy number variation among 178 Ethiopian P. vivax isolates using a PCR-based diagnostic method, a novel quantitative real-time PCR assay and whole genome sequencing. For the 145 symptomatic samples, PvDBP duplications were detected in 95 isolates, of which 81 had the Cambodian and 14 Malagasy-type PvDBP duplications. PvDBP varied from 1 to >4 copies. Isolates with multiple PvDBP copies were found to be higher in symptomatic than asymptomatic infections. For the 33 asymptomatic samples, PvDBP was detected with two copies in two of the isolates, and both were the Cambodian-type PvDBP duplication. PvDBP copy number in Duffy-negative heterozygotes was not significantly different from that in Duffy-positives, providing no support for the hypothesis that increased copy number is a specific association with Duffy-negativity, although the number of Duffy-negatives was small and further sampling is required to test this association thoroughly.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antigens, Protozoan / blood
  • Antigens, Protozoan / genetics*
  • DNA Copy Number Variations*
  • Duffy Blood-Group System / genetics
  • Erythrocytes / immunology
  • Erythrocytes / parasitology
  • Ethiopia / epidemiology
  • Female
  • Genome, Protozoan
  • Humans
  • Malaria, Vivax / epidemiology*
  • Malaria, Vivax / genetics
  • Malaria, Vivax / parasitology
  • Male
  • Plasmodium vivax / genetics*
  • Protozoan Proteins / blood
  • Protozoan Proteins / genetics*
  • Receptors, Cell Surface / blood
  • Receptors, Cell Surface / genetics*


  • Antigens, Protozoan
  • Duffy Blood-Group System
  • Duffy antigen binding protein, Plasmodium
  • Protozoan Proteins
  • Receptors, Cell Surface