Clinical and laboratory characteristics of infants with and without serious bacterial infections
| Variable | SBI (n=54) | Non SBI (n=133) | Overall (n=187) | P value |
| Age at presentation | 0.016 | |||
| 0 to 28 days, n (%) | 14 (25.9) | 65 (48.9) | 79 (42.2) | |
| 29 to 60 days, n (%) | 22 (40.7) | 38 (28.6) | 60 (32.1) | |
| 61 to 90 days, n (%) | 18 (33.3) | 30 (22.6) | 48 (25.7) | |
| Age in days, median (IQR) mean (SD) | 48 (28 to 69) 45 (24.5) | 29 (6 to 56) 33 (28.3) | 35 (9 to 61) 37 (27.7) | 0.004 <0.001* |
| Gender | ||||
| Male, n (%) | 43 (79.6) | 66 (49.6) | 109 (58.3) | <0.001 |
| Ethnicity, n (%) | 0.180 | |||
| Chinese | 35 (64.8) | 66 (49.6) | 101 (54.0) | |
| Malay | 12 (22.2) | 50 (37.6) | 62 (33.2) | |
| Indian | 3 (5.6) | 10 (7.5) | 13 (7.0) | |
| Others | 4 (7.4) | 7 (5.3) | 11 (5.9) | |
| Maternal positive GBS status, n (%) | 12 (22.2) | 24 (18.0) | 36 (19.3) | 0.511 |
| <24 hours of fever at presentation, n (%) | 38 (70.4) | 117 (88.0) | 155 (82.9) | 0.004 |
| Comorbidities, n (%) | 3 (5.6) | 2 (1.5) | 5 (2.7) | 0.120 |
| Length of hospital stay in days, median (IQR) | 4 (3 to 4) | 3 (3 to 4) | 3 (3 to 4) | 0.015 |
| Temperature °C, mean (SD) | 38.7 (0.6) | 38.5 (0.5) | 38.6 (0.6) | 0.051 |
| Heart rate per minute, mean (SD) | 168 (26) | 164 (19) | 166 (21) | 0.318 |
| Respiratory rate per minute, mean (SD) | 42 (6) | 41 (6) | 41 (6) | 0.216 |
| Pulse oximetry %, median (IQR) | 99 (98 to 100) | 99 (98 to 100) | 99 (98 to 100) | 0.495 |
| WBC, 109/L, median (IQR) mean (SD) | 13.8 (8.5 to 19.1) 14.1 (6.4) | 11.4 (8.5 to 13.6) 11.3 (4.4) | 11.8 (8.5 to 14.4) 12.1 (5.2) | 0.004 0.017* |
| ANC, 109/L, median (IQR) mean (SD) | 6.7 (3.1 to 9.5) 7.2 (4.4) | 4.1 (2.6 to 5.9) 4.6 (3.0) | 4.5 (2.9 to 6.9) 5.4 (3.6) | <0.001 <0.001* |
| NLR, median (IQR) mean (SD) | 1.3 (0.9 to 1.9) 1.6 (1.0) | 0.9 (0.6 to 1.5) 1.1 (0.8) | 1.0 (0.6 to 1.6) 1.2 (0.9) | 0.001 0.001* |
| PLR, median (IQR) mean (SD) | 86.7 (68.8 to 138.6) 105.9 (53.4) | 86.9 (69.5 to 14.4) 107.1 (73.1) | 86.9 (68.8 to 120.1) 106.7 (67.8) | 0.878 0.703* |
| MPV/PC, median (IQR) mean (SD) | 0.11 (0.07 to 0.15) 0.12 (0.05) | 0.12 (0.09 to 0.15) 0.13 (0.07) | 0.12 (0.08 to 0.15) 0.12 (0.06) | 0.768 0.634* |
| SBI (n=54) | Non SBI (n=125) | Overall (n=179) | ||
| CRP, mg/L, median (IQR) mean (SD) | 21.0 (7.2 to 48.7) 30.2 (30.1) | 2.3 (1.0 to 6.8) 7.5 (16.7) | 3.8 (1.0 to 17.1) 14.3 (23.9) | <0.001 <0.001* |
*P values performed on log-transformed data.
ANC, absolute neutrophil ratio; CRP, C-reactive protein; GBS, Group B Streptococcus; MPV/PC, mean platelet volume to platelet count ratio; NLR, neutrophil to lymphocyte ratio; PLR, platelet to lymphocyte ratio; SBI, serious bacterial infections; WBC, white blood cell count.