Participant flow diagram. The 313 individuals included in the study were classified into major groups (M- or M+) and further sub classified into three minor groups (PCR-/M-, PCR+/M- or PCR+/M+). For serology of total IgG and subclass, two patent P. falciparum mono-infection (N = 2) and P. falciparum mono-infection by PCR (N = 3) were excluded. Three hundred eight samples from the minor groups were used: PCR+/M- (N = 25), twenty five P. vivax infected individuals (three with mixed infections) had no malaria symptoms over two-month follow-up. Fifteen subjects from the PCR+/M + group had acute malaria during the study. Two hundred sixty eight were uninfected (PCR-/M-) at cross sectional. For subclass analysis, sera had sufficient amounts and that respond with total IgG anti ICB2-5 were evaluated, (N = 70) of PCR-/M-; (N = 13) of PCR+/M- and (N = 8) PCR+/M + .