Naturally Acquired Antibody Responses to Plasmodium vivax and Plasmodium falciparum Merozoite Surface Protein 1 (MSP1) C-Terminal 19 kDa Domains in an Area of Unstable Malaria Transmission in Southeast Asia
Fig 1
Natural antibody responses to recombinant PvMSP119 (A and C) and PfMSP119 (B and D) antigens.
Plasma samples from healthy endemic control (EC), P. falciparum patients (PF) and P. vivax patients (PV) were used in PvMSP119 or PfMSP119 ELISA, respectively. A and B: IgG levels in these samples for PvMSP119 (A) and PfMSP119 (B). Data shown as median ± interquartile range were analyzed by one-way nonparametric Kruskal-Wallis test and Dunn's test for multiple comparisons. C and D: Prevalence of IgG positive samples for PvMSP119 (C) and PfMSP119 (D). 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 p<0.01 and p<0.001, respectively.