Fig 3. Principal Component Analysis (PCA) plot illustrating genetic relatedness among P. vivax infections in Mauritania compared with previous data from other endemic countries [18–20].

The first two principal components are shown, illustrating that the parasite population in Mauritania is distinct from the Southeast Asian and Central and South American populations, and has only a minor degree of overlap with samples from Ethiopia. In agreement with Neighbour-Joining analysis of genetic distance (shown in Fig 2), the single isolate NKT136 from Nouakchott clustered with parasites from Southeast Asia. Further Principal Component Analysis of the Mauritanian data with each of the other populations separately confirm the population distinctness (with the exception of isolate NKT136), and also show that isolates from different sampled areas of Mauritania are not genetically separated (S2 Fig).