FIG. 2.

Levels of IgG, IgM, and IgA antibodies to T. gondii as determined by indirect ELISA using STAg or reverse ELISA using MAbs (A3A4, A4D12, and 1B8) in four groups of human sera: (A) recent infection defined by positive IgG, IgM, and IgA to T. gondii (n = 45); (B) transient infection defined by positive IgG and IgM but negative IgA to T. gondii (n = 40); (C) chronic infection defined by positive IgG but negative IgM and IgA to T. gondii (n = 55); and (D) negative IgG, IgM, and IgA to T. gondii (n = 35). Antibody levels are expressed as EI values, the dashed lines indicate the cutoff value (EI > 1.2), and the horizontal bars represent the mean of EI values.