Table 1. Characteristics of disease phenotypes in intramuscularly injected YFV-17D-infected mice.
| Characteristic | No clinical signs | Viscerotropic | Neurotropic |
| Disease manifestation | |||
| Found dead (%)* | 0 | 9 | 0 |
| Lethargic/hunched (%) | 0 | 91 | 0 |
| Paralysis (%) | 0 | 0 | 100 |
| Tissue pathology | |||
| Liver pathology (%) | 0 | 14 | 0 |
| Splenomegaly (%) | 0 | 23 | 0 |
| Intestinal haemorrhage (%) | 0 | 54 | 0 |
| Immune infiltrate in brain‡ | −/− | +/− | +/+ |
| Viral titre† | |||
| Brain | + | + | + |
| Muscle | +/− | + | +/− |
| Blood | – | +/− | +/− |
| Liver | – | +/− | +/− |
| Spleen | – | + | +/− |
*
Mice were checked every 12 h. Therefore, mice that were found dead had appeared healthy ≤12 h prior to their death, indicating rapid disease progression.
†
Viral titres were undetectable (–), variable (+/−, undetectable to ~105 p.f.u.) or high (+, >103 p.f.u./tissue).
‡
Immune infiltrate in brain was scored as high (+/+), medium (+/−), or low (−/−) according to data shown in Figure 4.