Natural antibody responses to recombinant PvMSP1₁₉ (A and C) and PfMSP1₁₉ (B and D) antigens.

<p>Plasma samples from healthy endemic control (EC), <i>P</i>. <i>falciparum</i> patients (PF) and <i>P</i>. <i>vivax</i> patients (PV) were used in PvMSP1₁₉ or PfMSP1₁₉ ELISA, respectively. <b>A</b> and <b>B</b>: IgG levels in these samples for PvMSP1₁₉ (<b>A)</b> and PfMSP1₁₉ <b>(B)</b>. Data shown as median ± interquartile range were analyzed by one-way nonparametric Kruskal-Wallis test and Dunn's test for multiple comparisons. <b>C</b> and <b>D</b>: Prevalence of IgG positive samples for PvMSP1₁₉ <b>(C)</b> and PfMSP1₁₉ <b>(D)</b>. Data were analyzed by χ² test. OD cutoff value was defined as the average of non-endemic control samples plus two standard deviations. OD ratio was referred to the observed OD value of a test sample divided by the cutoff value. OD ratio ≥ 1.0 was considered positive (above the threshold shown as dashed line at 1). ** and *** indicate significance at <i>p</i><0.01 and <i>p</i><0.001, respectively.