| mild | 0.77 |
| less severe than bacter… | 0.35 |
| severe | 0.34 |
| caused by influenza | 0.53 |
| treated with antiviral … | 0.40 |
| common in child | 0.38 |
| caused by adenovirus | 0.25 |
| complicated by an invas… | 0.16 |
| caused by the sars coro… | 0.16 |
| caused by hantavirus | 0.16 |
| caused by parainfluenza… | 0.16 |