Figure 1. Comparative analysis of serologic responses of horses exposed to human tick-borne relapsing fever agent Borrelia persica, Israel, 2025. Box-and-whisker plot demonstrates optical density measurements from seropositive (blue), seronegative (red), and negative control (green) horses. The dashed line represents the established cutoff value (optical density = 0.35). Statistical significance was determined using a Kruskal–Wallis test followed by Dunn multiple comparison test. Results significantly distinguish between the seropositive horses compared with the seronegative and control groups, whereas the seronegative group did not significantly differ from the negative control. Horizontal lines within boxes represent median values; box tops and bottoms indicate the upper and lower quartiles; error bars represent ranges. p values are indicated.