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Table 3 Characteristics and clinical presentation of infants hospitalized for bronchiolitis by nasal swab microbiota profile

From: The association between anterior nares and nasopharyngeal microbiota in infants hospitalized for bronchiolitis

Variables Corynebacterium-dominant profile, n = 109 (13.4%) Haemophilus-dominant profile, n = 59 (7.2%) Moraxella-dominant profile, n = 106 (13.0%) Enterobacter-dominant profile, n = 61 (7.5%) Staphylococcus-dominant profile, n = 363 (44.5%) Mixed profile, n = 117 (14.4%) P value
Characteristics
 Age (months), median (IQR) 3 (1–6) 5 (3–8) 4 (2–7) 4 (2–6) 3 (2–4) 4 (2–7) < 0.001
  < 2 36 (33.0) 7 (11.9) 24 (22.6) 14 (23.0) 132 (36.4) 23 (19.7) < 0.001
  2–5.9 44 (40.4) 25 (42.4) 48 (45.3) 34 (55.7) 178 (49.0) 58 (49.6)  
  6–11.9 29 (26.6) 27 (45.8) 34 (32.1) 13 (21.3) 53 (14.6) 36 (30.8)  
 Male sex 59 (54.1) 36 (61.0) 58 (54.7) 37 (60.7) 230 (63.4) 68 (58.1) 0.45
 Race/ethnicity        0.07
  Non-Hispanic white 53 (48.6) 23 (39.0) 49 (46.2) 20 (32.8) 177 (48.8) 38 (32.5)  
  Non-Hispanic black 18 (16.5) 11 (18.6) 22 (20.8) 22 (36.1) 80 (22.0) 30 (25.6)  
  Hispanic 34 (31.2) 24 (40.7) 31 (29.2) 17 (27.9) 93 (25.6) 44 (37.6)  
  Other 4 (3.7) 1 (1.7) 4 (3.8) 2 (3.3) 13 (3.6) 5 (4.3)  
 Parental history of asthma 30 (27.5) 15 (25.4) 42 (39.6) 26 (42.6) 124 (34.2) 37 (31.6) 0.18
 Maternal smoking during pregnancy 16 (14.7) 4 (6.8) 14 (13.2) 14 (23.0) 50 (13.8) 13 (11.1) 0.19
 Mode of birth        0.84
  Vaginal birth 71 (65.1) 37 (62.7) 65 (61.3) 41 (67.2) 248 (68.3) 75 (64.1)  
  C-section 38 (34.9) 21 (35.6) 38 (35.8) 20 (32.8) 111 (30.6) 41 (35.0)  
 Prematurity (32–37 weeks) 17 (15.6) 12 (20.3) 15 (14.2) 12 (19.7) 60 (16.5) 22 (18.8) 0.87
 Previous breathing problems before the index hospitalization* 23 (21.1) 12 (20.3) 27 (25.5) 17 (27.9) 62 (17.1) 26 (22.2) 0.26
 History of eczema 17 (15.6) 12 (20.3) 20 (18.9) 13 (21.3) 61 (16.8) 21 (17.9) 0.92
 Ever attended daycare 23 (21.1) 17 (28.8) 33 (31.1) 15 (24.6) 75 (20.7) 27 (23.1) 0.27
 Aeroallergen sensitization† 0 (0.0) 1 (1.7) 2 (1.9) 0 (0.0) 7 (1.9) 2 (1.7) 0.68
 Food sensitization† 21 (19.3) 9 (15.3) 22 (20.8) 13 (21.3) 64 (17.6) 23 (19.7) 0.92
 Children at home 84 (77.1) 48 (81.4) 88 (83.0) 49 (80.3) 285 (78.5) 92 (78.6) 0.90
 Mostly breastfed for the first 3 months of age 59 (54.1) 31 (52.5) 51 (48.1) 23 (37.7) 152 (41.9) 45 (38.5) 0.21
 Smoke exposure at home 17 (15.6) 5 (8.5) 18 (17.0) 14 (23.0) 55 (15.2) 18 (15.4) 0.42
 Antibiotic use before index hospitalization 29 (26.6) 30 (50.8) 44 (41.5) 27 (44.3) 96 (26.4) 28 (23.9) < 0.001
 Corticosteroid use before index hospitalization 13 (11.9) 13 (22.0) 19 (17.9) 11 (18.0) 46 (12.7) 19 (16.2) 0.31
Clinical presentation
 Month of hospitalization        0.06
  November 10 (9.2) 3 (5.1) 10 (9.4) 10 (16.4) 32 (8.8) 5 (4.3)  
  December 21 (19.3) 7 (11.9) 16 (15.1) 6 (9.8) 74 (20.4) 22 (18.8)  
  January 31 (28.4) 24 (40.7) 32 (30.2) 15 (24.6) 97 (26.7) 36 (30.8)  
  February 31 (28.4) 14 (23.7) 24 (22.6) 12 (19.7) 85 (23.4) 32 (27.4)  
  March 12 (11.0) 8 (13.6) 21 (19.8) 14 (23.0) 40 (11.0) 15 (12.8)  
  April 4 (3.7) 3 (5.1) 3 (2.8) 4 (6.6) 35 (9.6) 7 (6.0)  
 Breathing problem began < 1 day before the index hospitalization 5 (4.6) 2 (3.4) 8 (7.5) 3 (4.9) 20 (5.5) 10 (8.5) 0.67
 Weight at presentation (kg), median (IQR) 6 (5–8) 7 (6–8) 6 (5–8) 6 (5–8) 6 (5–7) 7 (5–8) < 0.001
 Respiratory rate at presentation (per minute), median (IQR) 48 (40–59) 50 (40–60) 49 (42–60) 50 (42–64) 50 (40–60) 50 (42–60) 0.26
 Oxygen saturation at presentation       0.006
  < 90% 7 (6.4) 13 (22.0) 4 (3.8) 7 (11.5) 31 (8.5) 11 (9.4)  
  90–93% 23 (21.1) 9 (15.3) 14 (13.2) 5 (8.2) 50 (13.8) 16 (13.7)  
  ≥ 94% 74 (67.9) 35 (59.3) 88 (83.0) 46 (75.4) 274 (75.5) 90 (76.9)  
 Retractions on examination        0.32
  None 18 (16.5) 6 (10.2) 24 (22.6) 13 (21.3) 58 (16.0) 17 (14.5)  
  Mild 42 (38.5) 21 (35.6) 45 (42.5) 23 (37.7) 160 (44.1) 55 (47.0)  
  Moderate/severe 43 (39.4) 30 (50.8) 33 (31.1) 23 (37.7) 127 (35.0) 45 (38.5)  
 Wheezing on examination 63 (57.8) 30 (50.8) 65 (61.3) 37 (60.7) 214 (59.0) 77 (65.8) 0.31
 Received antibiotics during pre-hospitalization visit 28 (25.7) 34 (57.6) 35 (33.0) 25 (41.0) 104 (28.7) 41 (35.0) < 0.001
 Received corticosteroids during pre-hospitalization visit 6 (5.5) 5 (8.5) 5 (4.7) 6 (9.8) 34 (9.4) 17 (14.5) 0.15
 Virology        0.11
  Sole RSV infection 56 (51.4) 30 (50.8) 69 (65.1) 34 (55.7) 225 (62.0) 60 (51.3)  
  Sole rhinovirus infection 7 (6.4) 4 (6.8) 4 (3.8) 8 (13.1) 17 (4.7) 7 (6.0)  
  RSV + rhinovirus coinfection 14 (12.8) 3 (5.1) 14 (13.2) 7 (11.5) 44 (12.1) 15 (12.8)  
  RSV + non-rhinovirus pathogens 14 (12.8) 15 (25.4) 9 (8.5) 6 (9.8) 34 (9.4) 15 (12.8)  
  Rhinovirus + non-RSV pathogens 2 (1.8) 2 (3.4) 3 (2.8) 2 (3.3) 9 (2.5) 5 (4.3)  
  Neither RSV nor rhinovirus‡ 11 (10.1) 5 (8.5) 6 (5.7) 4 (6.6) 26 (7.2) 9 (7.7)  
  No viral pathogens 5 (4.6) 0 (0.0) 1 (0.9) 0 (0.0) 8 (2.2) 6 (5.1)  
 Viral genomic load (CT-value), median IQR
  RSV 22 (20–25) 22 (21–26) 22 (21–25) 23 (21–25) 23 (21–25) 22 (21–27) 0.63
  RV 28 (26–31) 29 (24–34) 28 (27–36) 27 (25–34) 31 (27–36) 30 (27–36) 0.60
Outcomes
 Intensive care use‡ 20 (18%) 16 (27%) 6 (6%) 13 (21%) 47 (13%) 21 (18%)  
 Hospital length of stay ≥ 5 days 10 (9%) 19 (32%) 16 (15%) 8 (13%) 47 (13%) 18 (15%)  
 Hospital length of stay (day), median (IQR) 2 (1–4) 2 (2–5) 2 (1–3) 2 (1–3) 2 (1–3) 2 (1–3)  
  1. Data are number (%) of infants unless otherwise indicated. Percentages may not be equal to 100, because of missingness
  2. Patient characteristics and hospital course were compared using chi-square test or Kruskal-Wallis test across the identified nasopharyngeal microbiota profiles
  3. CT cycle threshold, IQR interquartile range, RSV respiratory syncytial virus
  4. *Defined as an infant having cough that wakes him/her at night and/or causes emesis, or when the child has wheezing or shortness of breath without cough
  5. †Defined by having one or more positive values for allergen-specific IgE
  6. ‡Defined as admission to intensive care unit and/or use of mechanical ventilation (continuous positive airway pressure and/or intubation during inpatient stay, regardless of location) at any time during the index hospitalization