FIG 3.

SGE or mosquito spot feeding enhances WNV viremia over a broad time frame. (A to C) Mice were inoculated s.c. with 0.5 μg SGE in the left rear footpad at the indicated times before (negative numbers) or after (positive numbers) inoculation with WNV (time zero). Control mice (identified by C on the x axis) received diluent and WNV at time zero. Viremia was measured at 24 (A), 48 (B), or 72 (C) hpi. (D) One to five uninfected C. tarsalis mosquitoes (average, 1.95) probed on the left rear footpad of mice at the indicated times relative to the time of inoculation with WNV (time zero). Control mice were not exposed to mosquitoes. (A to D) The data shown are combined from multiple experiments. Each symbol represents a single mouse (in panels A to C, n = 4 to 20 mice; in panel D, n = 8 to 16 mice), 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.