The SGE-mediated enhancement of WNV is highly localized. (A) Mice were inoculated s.c. with diluent (control) or 0.5 μg SGE in the left (L) or right (R) rear footpad. Sixteen hours later, the mice were inoculated s.c. with WNV in the left rear footpad. The data shown are combined from two experiments (n = 8 to 12 mice). (B) Mice were inoculated s.c. with 0.5 μg SGE into the left rear thigh (T), calf (C), or footpad (FP). Control mice received diluent in the left rear footpad. Mice were immediately inoculated s.c. with WNV in the left rear footpad. Data are from a single study (n = 8 mice). (A and B) Each symbol represents a single mouse, and bars indicate the means. Statistically significant differences between experimental and control mice were determined by the Mann-Whitney U test and are indicated as follows: *, P < 0.05; **, P < 0.01; ***, P < 0.001. The dashed line in panel B indicates the limit of detection of 500 PFU/ml.