FIG. 6.

39ns1 but not TR339 infection causes morbidity as defined by weight loss in 18-day-old mice. Eighteen-day-old mixed groups of male and female CD-1 mice were infected i.c. with 10³ PFU of either TR339 or 39ns1. Mice were weighed daily as an indicator of virus-induced morbidity. Mouse weight is plotted as a percentage of starting body weight over time. The data represent the mean percentage from five (TR339 and 39ns1) or four (mock) animals per group. ○, TR339-infected mice; ▴, 39ns1-infected mice; +, mock-infected mice. Error bars represent the standard error. The data shown represent one of four comparable experiments with 18- to 21-day-old mice.