Table 1.
Epidemiological, microbiological, and clinical characteristics of the study groups.
| Not exposed (n=27) | Exposed (n=54) | P-value a | |
|---|---|---|---|
| Epidemiological characteristics | |||
| Age, months, median (IQR) | 33 (19.0-49.5) | 28.5 (18.5-48.5) | 0.72 |
| Gender, male (%) | 12/27 (44.4) | 35/54 (64.8) | 0.13 |
| Birth weight, grams, mean (sd) b | 3260 (507) | 3358 (444) | 0.41 |
| Gestational age, weeks, median (IQR) c | 40 (38.2-40.4) | 40.0 (39.0-40.0) | 0.81 |
| House surface per inhabitant, m2, median (IQR) d | 20 (18.1-28.3) | 22 (16.7-28.8) | 0.87 |
| Seasonality, samples collected during viral season (%)* | 17/27 (63.0) | 31/54 (57.4) | 0.81 |
| Ethnicity, Caucasian (%) | 16/24 (66.7) | 34/48 (70.8) | 0.92 |
| Delivery mode, C-section (%) | 6/23 (26.1) | 7/42 (16.7) | 0.55 |
| Breastfeeding (%) | 23/26 (88.5) | 41/52 (78.8) | 0.36 k |
| Breastfeeding duration, months, median (IQR) e | 6.5 (1.6-12.0) | 6.0 (1.0-9.0) | 0.41 |
| Schooled (%) | 21/26 (80.8) | 44/51 (86.3) | 0.52 k |
| Family members under 5 years (%) | 9/25 (36.0) | 12/46 (26.1) | 0.55 |
| Parental smoking (%) | 8/26 (30.8) | 18/49 (36.7) | 0.79 |
| Basic educational level (%) | 3/19 (15.8) | 9/43 (20.9) | 0.74 k |
| ≥1 dose of Pneumococcal Conjugate Vaccine (%) | 15/27 (55.5) | 36/52 (69.2) | 0.34 |
| Microbiological characteristics | |||
| Viral study | |||
| DNA/RNA viral detection by multiplex PCR (%) | 22/27 (81.5) | 39/54 (72.2) | 0.42 k |
| DNA/RNA viral detection >2 viruses by multiplex PCR (%) | 9/27 (33.3) | 15/54 (27.8) | 0.79 |
| Human rhinovirus/enterovirus (%) | 16/27 (59.2) | 31/53 (58.5) | 1.00 |
| Human respiratory syncitial virus (A and B) (%) | 4/26 (15.4) | 4/53 (7.5) | 0.42 k |
| Human metapneumovirus (%) | 1/27 (3.7) | 2/53 (3.8) | 1.00 k |
| Human coronaviruses (OC43/229E/NL63) (%) | 2/27 (7.4) | 2/54 (3.7) | 0.60 k |
| Human parainfluenza viruses (1,2,3,4) (%) | 1/27 (3.7) | 6/53 (11.3) | 0.41 k |
| Human influenza viruses (A and B) (%) | 3/26 (11.5) | 4/53 (7.5) | 0.67 k |
| Human adenovirus (%) | 3/27 (11.1) | 8/53 (15.1) | 0.74 k |
| Human bocavirus (%) | 4/25 (16.0) | 6/53 (11.3) | 0.71 k |
| Pneumococcal study in invasive samples # | |||
| Pneumococcal serotype with high invasive disease potential (%) | 14/27 (51.8) | 18/36 (50.0) | 1.00 |
| Pneumococcal serotype covered by PCV13 vaccination (%) | 14/27 (51.8) | 18/36 (50.0) | 1.00 |
| Clinical characteristics | |||
| Time of fever before NPA collection, hours, median (IQR) f | 120 (78-144) | 128 (33-192) | 0.82 |
| Blood analytical parameters at admission | |||
| C -Reactive Protein, mg/L, median (IQR) g | 300 (205-324) | 268 (146-335) | 0.83 |
| Procalcitonin, ng/ml, median (IQR) h | 11.3 (6.7-17.2) | 4.3 (1.2 -15.1) | 0.37 |
| Hemoglobin, g/dl, median (IQR) i | 10.7 (10.1-11.7) | 10.8 (9.9-11.6) | 0.97 |
| Leukocytes, thousand/mm3, mean (SD) j | 16.8 (8.3) | 18.0 (8.9) | 0.57 |
| Clinical syndromes | |||
| Complicated pneumonia (%) | 16/27 (59.2) | 29/54 (53.7) | 0.81 |
| Non-complicated pneumonia (%) | 7/27 (25.9) | 8/54 (14.8) | 0.36 |
| Meningitis (%) | 3/27 (11.1) | 5/54 (9.2) | 1.00 k |
| Sepsis (%) | 0/27 (0.0) | 4/54 (7.4) | 0.29 k |
| Bacteremia (%) | 1/27 (3.7) | 4/54 (7.4) | 0.66 k |
| Arthritis (%) | 0/27 (0.0) | 4/54 (7.4) | 0.29 k |
| Hospital stay and complications | |||
| Length of Hospitalization stay, days, median (IQR) | 11.0 (8.0-15.0) | 10.0 (6.0-15.0) | 0.69 |
| ICU admission (%) | 4/27 (14.8) | 13/54 (24.1) | 0.40 k |
| Respiratory support (noninvasive ventilation and/or mechanical ventilation) (%) | 2/27 (7.4) | 11/54 (20.4) | 0.20 k |
| Thoracocentesis (%) | 10/27 (37.0) | 22/54 (40.7) | 0.94 |
T-test and Wilcoxon test were used for parametric and nonparametric continuous variables, respectively. Chi-square test was used for categorical variables.
Comparisons performed on 25 not exposed cases and 53 exposed cases.
Comparisons performed on 26 not exposed cases and 53 exposed cases.
Comparisons performed on 23 not exposed and 47 exposed cases.
Comparisons performed on 26 not exposed cases and 50 exposed cases.
Comparisons performed on 26 not exposed cases and 52 exposed cases.
Comparisons performed on 26 not exposed cases and 53 exposed cases.
Comparisons performed on 12 not exposed cases and 25 exposed cases.
Comparisons performed on 25 not exposed cases and 51 exposed cases.
Comparisons performed on 25 not exposed cases and 52 exposed cases.
Fisher exact tests were performed for categorical variables instead of chi-square tests in case of ≥25% of cells presented expected frequencies <5.
*Viral season was defined as the period of time corresponding to Influenza A and VRS circulation over the basal levels according to the Surveillance Plan of ARIs in Catalonia (PIDIRAC) (https://canalsalut.gencat.cat/ca/professionals/vigilancia-epidemiologica/pla-dinformacio-de-les-infeccions-respiratories-agudes-a-catalunya-pidirac/) and reports from the Hospital Surveillance Network for VRS in Catalonia (Vall d’Hebrón Hospital) (https://hospital.vallhebron.com/ca/actualitat/publicacions/informe-xarxa-de-vigilancia-hospitalaria-de-vrs).
#A total of three pneumococci could not be serotyped due to low bacterial load.
SD, Standard Deviation; IQR, Interquartile Range; NPA, Nasopharyngeal aspirate.