Figure 1.

Agreement between baseline Trichomonas vaginalis (Tv) serostatus and serostatus 1–3 years later among 248 male participants in the Southern Community Cohort Study, 2005–8

Baseline and repeat Tv antibody absorbance values for each participant are plotted. Absorbance cut-off values for Tv scores and the scores themselves (0, 1+, 2+, 3+, and 4+) are indicated for the baseline values on the Y axis and for the repeat values on the X axis. Seropositivity is defined as a score greater or equal to 3+. Baseline and repeat serostatus results that agree are found in the upper right-hand (both seropositive) and lower left-hand (both seronegative) quadrants; baseline seronegative and repeat seropositive results (“seroconversion”) are found in the lower right-hand quadrant; and baseline seropositive and repeat seronegative results (“seroreversion”) are found in the upper left-hand quadrant. All data points are indicated by circles. Unfilled circles represent agreement or disagreement by no more than one score. Filled circles indicate disagreement by more than one score. Datapoint 1 represents a man who had a score of 2+ at baseline and a score of 4+ on his repeat sample. Datapoints 2 and 3 represent men who had scores of 3+ at baseline and 1+ or less on their repeat samples.