Malaria Genomics and the Developing World

Malaria is a disease caused by parasites from genus Plasmodium , a member of the Apicomplexan family. Apicomplexans are unique in that they are the only fully parasitic large clade on the tree of life. It is thought that every type of mammal, bird, and reptile is parasitized by at least one species of Plasmodium (Morrison 2009 ) . Five Plasmodium species infect humans: Plasmodium falciparum , Plasmodium vivax , Plasmodium malariae , Plasmodium ovale , and Plasmodium knowlesi , which until recently was thought to infect only nonhuman primates (Cox-Singh et al. 2008 ) . P. falciparum and P. vivax are the most prevalent species, and P. falciparum is responsible for most cases of severe malaria and death. A key feature of Apicomplexans is that these eukaryotic organisms exist mainly in a haploid state with most having only a brief obligatory diploid phase. Another difference is the apicoplast, a plastid believed to have originated from the phagocytosis of a chloroplast-containing microorganism (Waller and McFadden 2005 ) . Current estimates place over one-third of the world’s population at risk of Plasmodium spp . infection. Malaria is transmitted throughout most of the tropics and subtropics, including sub-Saharan Africa, much of Asia, parts of Central and South America, and parts of the Middle East. However, most of the at-risk population lives in tropical Africa, where transmission is the highest, with an estimated 300–500 million cases of clinical malaria illness each year, of which slightly less than one million end in death, putting malaria in the top three major global killers along with HIV/AIDS and tuberculosis. Malaria genomic research to date has focused largely on P. falciparum as the leading cause of malaria-associated disease