| in europe | 4 | location |
| in 2009 | 2 | temporal |
| virus → cause → outbreak | 5 |
| virus → cause → epidemic | 4 |
| virus → cause → the outbreak | 3 |
| negative | neutral | positive |
| 0.747 | 0.238 | 0.015 |
| Raw frequency | 12 |
| Normalized frequency | 0.335 |
| Modifier score | 0.500 |
| Perplexity | 233.027 |