Genetic relationship between Djiboutian Plasmodium falciparum genotypes observed at four time points (1998, 1999, 2002, and 2009). Analysis stratified by sampling year. The numbers of observed genotypes were 27, 34, 17, and 5 in 1998, 1999, 2002, and 2009, respectively. The same colour code as in Figure 3 is used. Here, the colour of the text and circle corresponds to the year in which the genotypes were observed. For example, the diagram for 2002 shows new genotypes first detected in 2002 (green circle with numbers in white), genotypes previously observed in 1999 (blue circle with numbers in white), and genotypes previously observed in both 1998 and 1999 (blue circle with numbers in red). Three Ethiopian genotypes sampled in 2008 (genotypes 32, 39, and 46) were grouped with 2009 samples.