Table 1 Characteristics of patients by age group and overall
Characteristic | < 1 y N = 39 | 1–2 y N = 111 | 3–4 y N = 77 | 5–13 y N = 103 | 14–17 y N = 7 | 18–64 y N = 135 | ≥65 y N = 30 | Overall N = 502 |
|---|---|---|---|---|---|---|---|---|
Age (y), median [IQR] | 0.7 [0.4–0.9] | 1 [1–2] | 4 [3–4] | 7 [6–9] | 15 [15–16.5] | 45 [35–55] | 76 [68.3–80.8] | 5.5 [2–36] |
Sex, n (%) | ||||||||
Male | 20 (51.3) | 60 (54.1) | 41 (53.2) | 57 (55.3) | 5 (71.4) | 46 (33.8) | 15 (50.0) | 244 (48.6) |
Female | 19 (48.7) | 51 (45.9) | 36 (46.8) | 46 (44.7) | 2 (28.6) | 89 (65.9) | 15 (50.0) | 258 (51.4) |
Smoking status, n (%)a | ||||||||
Never smoked | 25 (64.1) | 27 (24.3) | 44 (57.1) | 63 (61.2) | 7 (100.0) | 61 (45.2) | 10 (33.3) | 282 (56.2) |
Past smoker | 4 (10.3) | 12 (10.8) | 9 (11.7) | 8 (7.8) | 0 (0.0) | 32 (23.7) | 15 (50.0) | 80 (15.9) |
Current smoker | 10 (25.6) | 72 (64.9) | 24 (31.2) | 32 (31.1) | 0 (0.0) | 42 (31.1) | 5 (16.7) | 140 (27.9) |
Comorbidities, n (%) | ||||||||
Any | 1 (2.6) | 6 (5.4) | 2 (2.6) | 8 (7.8) | 2 (28.6) | 64 (47.4) | 25 (83.3) | 108 (21.5) |
Cardiovascular disease | 0 (0.0) | 1 (0.9) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 30 (22.2) | 23 (76.7) | 54 (10.8) |
COPD | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 6 (4.4) | 4 (13.3) | 10 (2.0) |
Asthma | 0 (0.0) | 1 (0.9) | 1 (1.3) | 4 (3.9) | 0 (0.0) | 3 (2.2) | 1 (3.3) | 10 (2.0) |
Diabetes | 0 (0.0) | 0 (0.0) | 0 (0.0) | 1 (1.0) | 1 (14.3) | 11 (8.1) | 6 (20.0) | 19 (3.8) |
Immunodeficiency | 1 (2.6) | 3 (2.7) | 1 (1.3) | 1 (1.0) | 1 (14.3) | 11 (8.1) | 0 (0.0) | 18 (3.6) |
Renal impairment | 1 (2.6) | 0 (0.0) | 0 (0.0) | 1 (1.0) | 0 (0.0) | 5 (3.7) | 2 (6.7) | 9 (1.8) |
Autoimmune disease | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 10 (7.4) | 2 (6.7) | 12 (2.4) |
Neuromuscular disease | 0 (0.0) | 1 (0.9) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 6 (4.4) | 7 (23.3) | 14 (2.8) |
Cirrhosis/liver disease | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 21 (15.6) | 1 (3.3) | 22 (4.4) |
Neoplasm | 0 (0.0) | 0 (0.0) | 0 (0.0) | 1 (1.0) | 0 (0.0) | 3 (2.2) | 2 (6.7) | 6 (1.2) |
Pregnant, n (%) | – | – | – | – | 0 (0.0) | 7 (5.2) | – | 7 (1.4) |
ILI symptoms, n (%) | ||||||||
Fever | – | – | – | 101 (98.1) | 7 (100.0) | 109 (80.7) | 25 (83.3) | 242 (88.4)b |
Malaise | – | – | – | 90 (87.4) | 7 (100.0) | 128 (94.8) | 27 (90.0) | 252 (91.6)b |
Headache | – | – | – | 70 (68.0) | 6 (85.7) | 109 (80.7) | 17 (56.7) | 202 (73.5)b |
Myalgia | – | – | – | 39 (37.9) | 5 (71.4) | 99 (73.3) | 19 (63.3) | 162 (58.9)b |
Cough | – | – | – | 92 (89.3) | 6 (85.7) | 111 (82.2) | 27 (90.0) | 236 (85.8)b |
Sore throat | – | – | – | 77 (74.8) | 7 (100.0) | 77 (57.0) | 11 (36.7) | 172 (62.5)b |
Shortness of breath | – | – | – | 15 (14.6) | 4 (57.1) | 65 (48.1) | 21 (70.0) | 105 (38.2)b |
Tachypneac | 2 (5.1) | 11 (9.9) | 15 (19.5) | – | – | – | – | 28 (12.3)d |
Hospitalizations in previous 12 mo, n (%) | ||||||||
1 | 8 (20.5) | 30 (27.0) | 22 (28.6) | 19 (18.4) | 1 (14.3) | 14 (10.4)e | 10 (33.3) | 104 (20.8)f |
≥ 2 | 8 (20.5) | 19 (17.1) | 14 (18.2) | 11 (10.7) | 1 (14.3) | 10 (7.5)e | 5 (16.7) | 68 (13.6)f |
Outpatient consultations in previous 3 mo, n (%) | ||||||||
1 | 11 (29.0)g | 26 (23.4) | 15 (19.7)h | 17 (16.5) | 2 (28.6) | 22 (16.4)e | 8 (26.7) | 101 (20.2)i |
≥ 2 | 11 (29.0)g | 50 (45.0) | 34 (44.7)h | 41 (39.8) | 1 (14.3) | 14 (10.4)e | 5 (16.7) | 156 (31.3)i |
Vaccinated against influenza in 2017–2018, n (%) | 0 (0.0)j | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 17 (12.6) | 0 (0.0) | 17 (3.4) |
≥ 14 days before ILI onsetk | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 10 (7.4) | 0 (0.0) | 10 (2.0) |
Patients with comorbiditiesl | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 8 (12.5) | 0 (0.0) | 8 (7.4) |
Vaccinated in previous seasons, n (%) | ||||||||
2016–2017 | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 14 (10.4) | 1 (3.3) | 15 (3.0) |
2015–2016 | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 17 (12.6) | 2 (6.7) | 19 (3.8) |
Duration of hospitalization (days), median [IQR] | 5 [4–6.75]g | 5 [3–6.5] | 5 [4–6] | 5 [4–7]m | 5 [4.5–8.5] | 5 [3–7] | 7 [6–9.5] | 5 [3–7]i |
Antiviral treatment prescribed, n (%) | 38 (97.4) | 108 (97.3) | 76 (98.7) | 99 (96.1) | 5 (71.4) | 106 (78.5) | 22 (73.3) | 454 (90.4) |
Intensive care received, n (%) | ||||||||
ICU admission | 0 (0.0) | 4 (3.6) | 1 (1.3) | 2 (1.9) | 0 (0.0) | 4 (3.0) | 0 (0.0) | 11 (2.2) |
Mechanical ventilation | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 1 (0.7) | 0 (0.0) | 1 (0.2) |
Death while hospitalized, n (%) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 1 (0.7) | 0 (0.0) | 1 (0.2) |