Immune recognition of different P. vivax and P. falciparum stage-specific antigens.

Antigen-specific total IgG in sera of the donors living in malaria-endemic regions of Colombia (Apartado and Turbo) were assessed by ELISA against P. vivax circumsporozite protein (PvCSP), blood stage antigens (PvMSP1, PvDBP), P. falciparum circumsporozoite protein (PfCSP) and blood stage antigen (PfMSP1). A sample is considered positive if the index of reactivity (IR) is greater or equal to 1. IR is calculated as the average OD of sample divided by the cut-off OD with the cut of OD being the sum of average OD values of US donors (with no prior exposure to malaria) + 3 standard deviations. Listed are the mean and SD of the IR, the number and percentage of positive samples (#Pos (%)), P values were caulcated by Chi-squared test.