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Table 3 Characteristics of laboratory confirmed influenza cases by virus type

From: The burden of laboratory-confirmed influenza infection in Lebanon between 2008 and 2016: a single tertiary care center experience

CharacteristicsInfluenza A,N = 1529Influenza B,N = 242Co-infection A&B,N = 55p-value
 n (%)n (%)n (%) 
Season (N = 1826)   < 0.001b
Jan 2008-Jun 200812 (66.7)6 (33.3)0 (0.0) 
2008–200947 (78.3)6 (10.0)7 (11.7) 
2009–2010529 (97.6)2 (0.4)11 (2.0) 
2010–201143 (58.9)25 (34.2)5 (6.8) 
2011–201292 (84.4)2 (1.8)15 (13.8) 
2012–201393 (73.8)27 (21.4)6 (4.8) 
2013–2014183 (89.3)17 (8.3)5 (2.4) 
2014–2015153 (64.3)82 (34.5)3 (1.3) 
2015–2016377 (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 years140 (9.2)27 (11.2)8 (14.5) 
Gender (N= 1826)   0.992
Male764 (50.0)121 (50.0)27 (49.1) 
Female765 (50.0)121 (50.0)28 (50.9) 
Underlying medical conditions (N = 1300)
Any511 (47.8)89 (45.2)15 (44.1)0.74
Cardiovascular disease179 (16.7)35 (17.8)8 (23.5)0.563
Chronic pulmonary disease51 (4.8)3 (1.5)0 (0.0)0.054
Asthma135 (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 Mellitus81 (7.6)13 (6.6)2 (5.9)0.938a
Renal disease43 (4.0)8 (4.1)1 (2.9)1.000a
Neuromuscular disorders8 (0.7)4 (2.0)0 (0.0)0.204a
Neurological disorders47 (4.4)8 (4.1)3 (8.8)0.395a
Malignancy136 (12.7)27 (13.7)1 (2.9)0.213a
Hemoglobinopathy27 (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
CharacteristicsInfluenza A,N = 381Influenza B,N = 84Co-infection A&B,N = 10p-value
n (%)n (%)n (%) 
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
  1. Percentages are expressed within each influenza type, except for the season variable in which percentages are expressed within each season.
  2. Pearson’s Chi-Square test was used (no expected count less than 5).
  3. Independent Sample-t test is used to compare means.
  4. a Fisher’s exact test was used when expected count was less than 5
  5. b Monte Carlo estimate was used when the data set was too large to compute exact significance
  6. c Two patients were excluded; one stayed in 113 days and the other stayed for 262 days related to their underlying medical condition (Neuromuscular disease and cerebral palsy)