Titers of SFTSV in mouse organs. Mice were inoculated with 10 FFU of SFTSV YG1. Three female mice were euthanized for virus titration at 3, 5, and 7 days p.i. The virus titers in the mouse brains, lungs, livers, spleens, kidneys, intestines, and plasma were measured by focus-forming assay. The values are shown as means ± SDs (n = 3). *, P < 0.05 for comparisons for each mouse strain.