Table 1.

Characteristics of 37 infants with RSV or non-RSV bronchiolitis as assessed by nasopharyngeal secretion PCR testing.

Characteristics	RSV bronchiolitis group (n = 25)	Non-RSV bronchiolitis group (n = 12)	P-value
Demographics
Age, months, mean (SD)	2.16 (0.44)	3.83 (0.88)	0.05
Male sex	17 (68.0)	6 (50.0)	0.24
Caucasian race	23 (92.0)	12 (100)	0.45
Birth history
Cesarean delivery	11 (44.0)	7 (58.3)	0.32
Prematurity (32–37 weeks)	4 (16.0)	2 (16.7)	0.65
ED presentation signs/symptoms
Fever	8 (32.0)	7 (58.3)	0.12
Dyspnea	24 (96.0)	7 (58.3)	0.001
Rhinitis	13 (52.0)	5 (41.7)	0.41
Increased respiratory effort indices a
Retractions	20 (80.0)	7 (58.3)	0.0001
Wheezes/Crackles (rales)	22 (88.0)	7 (58.3)	0.0001
Tachypnea	10 (40.0)	3 (25.0)	0.0001
Oxygen saturation (SpO2) <90%	24 (96.0)	5 (41.7)	0.001
Impaired feeding	19 (76.0)	4 (33.3)	0.04
(Co)infection by viruses other than RSV b
Rhinovirus	4 (16.0)	6 (50.0)	0.021
Influenza virus	0 (0.0)	2 (16.7)	0.026
Systemic antibiotic use after bronchiolitis diagnosis c	13 (52.0)	7 (58.3)	0.49
ICU and intubation
No ICU	21 (84.0)	12 (100)	0.19
ICU without intubation	2 (8.0)	0 (0.0)	—
ICU with intubation	2 (8.0)	0 (0.0)	—
LOS, days, median (IQR)	7 (3–14)	5 (5–10)	0.11

Data are no. (%) of infants unless otherwise indicated. —, not computed.

ED, emergency department; ICU, intensive care unit; IQR, interquartile range; LOS, length of hospital stay; PCR, polymerase chain reaction; RSV, respiratory syncytial virus; SD, standard deviation; SpO₂, saturation of peripheral oxygen.

^aOf listed indices, SpO₂ <90% value for each infant was determined through repeated measurements by pulse oximetry.

^bAccording to PCR testing performed on the nasopharyngeal secretions used to determine the RSV or non-RSV etiology of bronchiolitis.

^cDiagnosis was concomitant with the fecal sampling that was, indeed, obtained before patients were treated with antibiotics (see text for details).