| Variables | Symptomatic form | p | |
| Yes | No | ||
| Age |
|
|
|
| 0 to 5 | 14 | 1 | 0.259 |
| 6 to 10 | 13 | 1 | 0.422 |
| 11 to 15 | 19 | 8 | 0.028 |
| Sexe |
|
|
|
| Girl | 27 | 3 | 0.099 |
| Boy | 19 | 7 |
|
| Pathological history |
|
|
|
| Non | 1 | 49 | <0.0001 |
| Asthma | 3 | 2 | 0.002 |
| Heart disease | 2 | 0 | 0.0001 |
| Sickle cell disease | 1 | 0 | 0.103 |
| Contact case |
|
|
|
| Yes | 14 | 6 | 0.077 |
| No | 32 | 4 |
|