Figure 2.

Global distribution and transmission of Plasmodium species in human and animal populations. Plasmodium falciparum (red), Plasmodium vivax (green), Plasmodium malariae (purple) and the two species of Plasmodium ovale (pink) can be found in all malaria-endemic areas to varying extents. Additionally, Plasmodium knowlesi (blue) is found in Southeast Asia. Arrows between the different hosts indicate established transmission of the different parasite species within the human population, and/or between or from nonhuman primates. The dotted arrows show potential transmission of parasites to look out for, based on population surveys. All arrows are similarly color-coded. Plasmodium species related to the main human species are in boxes in corresponding colors and species for which cases of human infection have been observed (experimentally or naturally) are marked with an asterisk. DARC, Duffy antigen receptor for chemokines.