Analysis of genomic diversity within all P. falciparum infection samples analysed from six West African countries using genome wide sequence data. The fixation index FWS is an inverse measure of within-infection diversity compared to the overall diversity in the population, so that a value of 1.0 indicates no variation within an infection, and lower values indicate infections with more diversity. Each point plots the value of an individual infection sample, and for each country the values are plotted in ascending order so that the cumulative proportions may be read along the x-axis. The dashed line corresponds to FWS = 0.95, an arbitrary cut-off measurement above which an infection is considered to be virtually dominated by a single genotype. Mean values for each sampled site are shown in Table 1, and values for all individual infections are given in Table S1.