Analysis of genetic similarity between Djiboutian Plasmodium falciparum populations (1998, 1999, 2002, and 2009) Plasmodium falciparum populations in Djibouti (1998 red dot, 1999 blue dot, 2002 light green dot, and 2009 khaki dot; sampling details are presented in the text and Figure 1) were compared based on the genotyping of four microsatellites. Pairwise Fst indices between the years studied are presented in the table at the top left. Statistically significant Fst values (P < 0.05) are underlined. Multiple correspondence analysis (also called factorial correspondence analysis) was performed with Genetix software , using populations’ centroid as the active point. Axes FCA I and FCA II are the first two order factors representing 51.7% and 42.4% of the total inter-centroid variance, respectively. Ellipses around the centroids enclose 95% of the projected genotypes on the FCA plan and were calculated and graphically represented using R software . Genotype frequencies in 2009 did not allow ellipse representation.