FIG 3.

Ex vivo drug susceptibility of P. falciparum isolates from Cambodia by year and region. Box-whisker plots of IC₅₀s (in nanomolars) are shown for each drug stratified by collection year and region: west (gray), north (pink), and south (green). Dashed lines denote median IC₅₀s against the P. falciparum W2 reference clone and interquartile ranges. Significant P values by Mann-Whitney U test indicate differences in IC₅₀s between regions within the same year. A significant progressive decline in MQ IC₅₀s and rise in PPQ IC₅₀s during 2009 to 2013 in northern isolates is denoted by an asterisk (P < 0.001 by Kruskal-Wallis test).