FIG. 2.

IgG antibody responses in leptospirosis patients and control groups to recombinant leptospiral proteins as determined by ELISA. Results are shown for three selected recombinant antigens, at concentrations of 25 ng of antigen per well (rHsp58 and rOmpL1) or 5 ng of antigen per well (rLipL32). Absorbance (OD₄₅₀) values are shown for reactions with serum samples, diluted 50-fold, from healthy individuals in an endemic region for leptospirosis in Salvador, Brazil (group A, □), or a nonendemic U.S. region (group B, Δ) compared to paired serum samples from 50 patients with confirmed leptospirosis from Salvador, Brazil (group C, acute-phase ● or group D, convalescent-phase ▪). Fifty samples were tested in each group. Median absorbance values for each group of samples are shown as solid lines. The cutoff value, defined as the absorbance value for the 96th percentile of the group of 50 serum samples from healthy control individuals from Salvador, Brazil, are represented as dashed lines.