Plasmodium vivax Infections of Duffy-Negative Erythrocytes: Historically Undetected or a Recent Adaptation?

Abstract

Plasmodium vivax is the main cause of malarial disease in Asia and South America. Plasmodium vivax infection was thought to be absent in African populations who are Duffy blood group antigen negative (Duffy-negative). However, many cases of P. vivax infection have recently been observed in Duffy-negative Africans. This raises the question: were P. vivax infections in Duffy-negative populations previously missed or has P. vivax adapted to infect Duffy-negative populations? This review focuses on recent P. vivax findings in Africa and reports views on the parasite ligands that may play a role in Duffy-negative P. vivax infections. In addition, clues gained from studying P. vivax infection of reticulocytes are presented, which may provide possible avenues for establishing P. vivax culture in vitro.

Keywords: Duffy blood group antigen; Duffy-negative; Plasmodium vivax; ligands.

Figure 1. Plasmodium vivax infection in Duffy-negative populations in Africa

Map showing the regions on the African continent in which P. vivax infection in Duffy-negative people occurs. Red circles represent P. vivax infection in countries where both Duffy-positive and Duffy-negative people live side-by-side. Yellow circles represent molecular evidence of P. vivax infection in Duffy-negative individuals living in predominantly Duffy-negative populations in Sub-Saharan Africa. Green circles represent populations with P. vivax infection, but in which the Duffy status has not been checked. The map has been adapted from Wikimedia.