Table 1.
Characteristics of influenza A (H3N2) cases and controls—2018/2019 season.
| Variables | Controls (n = 744) | Cases (n = 435) | Total (n = 1179) | p-Value a |
|---|---|---|---|---|
| Age group (years) | ||||
| 0.5-4 | 252 | 104 | 356 | >0.01 |
| 17-May | 136 | 183 | 319 | |
| 18-44 | 204 | 96 | 300 | |
| 45-64 | 97 | 29 | 126 | |
| ≥ 65 | 55 | 23 | 78 | |
| Sex | ||||
| Male | 368 | 218 | 586 | 0.83 |
| Female | 376 | 217 | 593 | |
| Background Disease | ||||
| No | 596 | 387 | 983 | >0.01 |
| Yes | 148 | 48 | 196 | |
| Days between Symptom onset and Swabbing | ||||
| 0-1 | 302 | 155 | 457 | 0.09 |
| 04-Feb | 379 | 250 | 629 | |
| 07-May | 63 | 30 | 93 | |
| Month of Sample Collection | ||||
| October | 107 | 1 | 108 | >0.01 |
| November | 150 | 18 | 168 | |
| December | 183 | 110 | 293 | |
| January | 230 | 135 | 365 | |
| February | 126 | 69 | 195 | |
| March | 43 | 7 | 50 | |
| Influenza Vaccine | ||||
| No | 634 | 360 | 994 | 0.26 |
| Yes | 110 | 75 | 185 | |
a Statistical significance for differences between cases and controls.