August 28, 2018

Nicholas Brazeau (University of North Carolina, Chapel Hill)

The Evolutionary Origins and Global Dispersal of Plasmodium vivax


Malaria in humans is caused by several different parasites. One in particular, Plasmodium vivax, is believed to have evolved in African non-human apes prior to the parasite making the zoonotic leap and infecting their closest cousin, us! Humans then transported the parasite to Asia and Latin America, where today the disease afflicts millions. Although originating in central Africa, vivax malaria has been considered absent in these areas due to the high prevalence of a mutation that confers the Duffy-negative phenotype, offering protection against P. vivax infection. However, recent evidence has begun to overturn this view, as P. vivax has been found in several African countries among individuals with the supposed protective mutation. Through a large, representative population study of the Democratic Republic of the Congo, our group h as identified several P. vivax cases infecting Duffy-negative (“protected”) individuals. I am studying these new cases to determine what has caused their reemergence and their evolutionary origins by comparing them to the potentially ancestral African non-human ape sequences. Determining the evolutionary origins of P. vivax will help us to better understand drug resistance and to devise better malaria control and elimination interventions.