Table 3 Characteristics of laboratory confirmed influenza cases by virus type
Characteristics | Influenza A,N = 1529 | Influenza B,N = 242 | Co-infection A&B,N = 55 | p-value |
| Â | n (%) | n (%) | n (%) | Â |
Season (N = 1826) |  |  |  | < 0.001b |
Jan 2008-Jun 2008 | 12 (66.7) | 6 (33.3) | 0 (0.0) | Â |
2008–2009 | 47 (78.3) | 6 (10.0) | 7 (11.7) |  |
2009–2010 | 529 (97.6) | 2 (0.4) | 11 (2.0) |  |
2010–2011 | 43 (58.9) | 25 (34.2) | 5 (6.8) |  |
2011–2012 | 92 (84.4) | 2 (1.8) | 15 (13.8) |  |
2012–2013 | 93 (73.8) | 27 (21.4) | 6 (4.8) |  |
2013–2014 | 183 (89.3) | 17 (8.3) | 5 (2.4) |  |
2014–2015 | 153 (64.3) | 82 (34.5) | 3 (1.3) |  |
2015–2016 | 377 (82.9) | 75 (16.5) | 3 (0.7) |  |
Age group (N= 1826) | ||||
[0–2 years [ | 134 (8.8) | 28 (11.6) | 11 (20.0) | 0.039b |
[2–5 years [ | 205 (13.4) | 25 (10.3) | 9 (16.4) |  |
[5–10 years [ | 289 (18.9) | 44 (18.2) | 5 (9.1) |  |
[10–19 years [ | 283 (18.5) | 37 (15.3) | 7 (12.7) |  |
[19–50 years [ | 340 (22.2) | 56 (23.1) | 14 (25.5) |  |
[50–65 years [ | 138 (9.0) | 25 (10.3) | 1 (1.8) |  |
≥ 65 years | 140 (9.2) | 27 (11.2) | 8 (14.5) |  |
Gender (N= 1826) |  |  |  | 0.992 |
Male | 764 (50.0) | 121 (50.0) | 27 (49.1) | Â |
Female | 765 (50.0) | 121 (50.0) | 28 (50.9) | Â |
Underlying medical conditions (N = 1300) | ||||
Any | 511 (47.8) | 89 (45.2) | 15 (44.1) | 0.74 |
Cardiovascular disease | 179 (16.7) | 35 (17.8) | 8 (23.5) | 0.563 |
Chronic pulmonary disease | 51 (4.8) | 3 (1.5) | 0 (0.0) | 0.054 |
Asthma | 135 (12.6) | 20 (10.2) | 5 (14.7) | 0.543 |
Immunosuppressive state (other than malignancy) | 16 (1.5) | 3 (1.5) | 0 (0.0) | 1.000a |
Diabetes Mellitus | 81 (7.6) | 13 (6.6) | 2 (5.9) | 0.938a |
Renal disease | 43 (4.0) | 8 (4.1) | 1 (2.9) | 1.000a |
Neuromuscular disorders | 8 (0.7) | 4 (2.0) | 0 (0.0) | 0.204a |
Neurological disorders | 47 (4.4) | 8 (4.1) | 3 (8.8) | 0.395a |
Malignancy | 136 (12.7) | 27 (13.7) | 1 (2.9) | 0.213a |
Hemoglobinopathy | 27 (2.5) | 3 (1.5) | 0 (0.0) | 0.749a |
Antibiotic prescription (N = 1201) | 395 (40.0) | 87 (47.8) | 12 (37.5) | 0.134 |
Antiviral prescription (N = 1191) | 684 (69.8) | 119 (65.7) | 17 (56.7) | 0.192 |
Radiologically confirmed pneumonia (N = 739) | 189 (31.5) | 45 (39.1) | 7 (29.2) | 0.260 |
Hospitalization rate (N = 1784) | 381 (25.4) | 84 (36.2) | 10 (18.5) | 0.001 |
Characteristics | Influenza A,N = 381 | Influenza B,N = 84 | Co-infection A&B,N = 10 | p-value |
n (%) | n (%) | n (%) | Â | |
Progression of illness and in-hospital outcome | ||||
Moderate to severe disease (N = 470) | 224 (59.4) | 59 (71.1) | 7 (70.0) | 0.129a |
ICU admission (N = 475) | 51 (13.4) | 15 (17.9) | 4 (40.0) | 0.042a |
Oxygen therapy (N = 470) | 87 (23.0) | 20 (24.4) | 4 (40.0) | 0.399a |
Mortality (N = 470) | 15 (4.0) | 3 (3.7) | 0 (0.0) | 1.000a |
Hospital stay duration, mean (±SD) (N = 473)c | ||||
|  | 6.8 (±8.4) | 6.8 (±6.7) | 16.7 (±23.8) | 0.02 |