Table 2.
Clinical features of children with moderate-to-severe influenza at Kaiser Permanente Northern California, 2013–2014 influenza season.
| Symptoms | <6 months, n = 33 (%) |
≥6 to <36 months, n = 189 (%) | ≥3 to <9 years, n = 177 (%) |
≥9 to <18 years, n = 139 (%) |
|---|---|---|---|---|
| Criteria for inclusion in moderate - to - severe cohorta | ||||
| Fever >39°C | 8 (24.2) | 81 (42.9) | 77 (43.5) | 74 (53.2) |
| AOM | 2 (6.1) | 53 (28.0) | 23 (13.0) | 4 (2.9) |
| LRTI | 27 (81.8) | 121 (64.0) | 110 (62.1) | 82 (59.0) |
| Extra-pulmonary complications | 1 (3.0) | 17 (9.0) | 10 (5.6) | 6 (4.3) |
| Breakdown of criteriab | ||||
| Fever >39°C only | 4 (12.1) | 33 (17.5) | 45 (25.4) | 53 (38.1) |
| Fever >39°C + AOM only | 0 (0) | 6 (3.2) | 5 (2.8) | 0 (0) |
| Fever >39°C + LRTI only | 4 (12.1) | 28 (14.8) | 24 (13.6) | 16 (11.5) |
| Fever >39°C + extra-pulmonary complications only | 0 (0) | 6 (3.2) | 1 (0.6) | 0 (0) |
| LRTI only | 22 (66.7) | 61 (32.3) | 75 (42.4) | 60 (43.2) |
| AOM only | 2 (6.1) | 17 (9.0) | 13 (7.3) | 3 (2.2) |
| Extra-pulmonary complications only | 0 (0) | 4 (2.1) | 3 (1.7) | 1 (0.7) |
| AOM + LRTI only | 0 (0) | 22 (11.6) | 4 (2.3) | 1 (0.7) |
| AOM + extra-pulmonary complications only | 0 (0) | 0 (0) | 0 (0) | 0 (0) |
| LRTI + extra-pulmonary complications only | 1 (3.0) | 3 (1.6) | 5 (2.8) | 0 (0) |
| Fever >39°C + AOM + LRTI only | 0 (0) | 5 (2.6) | 1 (0.6) | 0 (0) |
| Fever >39°C + AOM + extra-pulmonary complications only | 0 (0) | 2 (1.1) | 0 (0) | 0 (0) |
| Fever >39°C + LRTI + extra-pulmonary complications only | 0 (0) | 1 (0.5) | 1 (0.6) | 5 (3.6) |
| AOM + LRTI + extra-pulmonary complications only | 0 (0) | 1 (0.5) | 0 (0) | 0 (0) |
aCategories are not mutually exclusive and add up to more than total per column.
bCategories are mutually exclusive.
AOM: physician-confirmed acute otitis media; LRTI: physician-confirmed lower respiratory tract illness;
Extra-pulmonary complications: physician-diagnosed serious extra-pulmonary complications (such as myositis, encephalitis, seizures, or myocarditis).