Table 2. Risk factors for invasive Group B Streptococcal (GBS) disease in early-onset and late-onset disease cases and matched controls.
| Cases | Controls | Univariate-OR (95%CI) 1 | p-value | Multivariate-OR (95%CI) 2 | p-value | |
|---|---|---|---|---|---|---|
| Early-onset disease | n = 56 | n = 323 | ||||
| Maternal GBS colonization | 35/47 (74.5) | 81/323 (25.1) | 8.71 (4.15–19.23) | <0.001 | 3.38 (0.77–14.83) | 0.107 |
| Prolonged ROM (>18hours) 3 | 14/49 (28.6) | 32/313 (10.2) | 3.51 (1.57–7.54) | <0.001 | 2.08 (0.61–7.08) | 0.239 |
| Maternal fever (≥38.0°C) 4 | 1/50 (2.0) | 0/319 (0) | 0.136 | |||
| Offensive liquor | 10/52 (19.2) | 1/317 (0.3) | 75.24 (10.05–3274.04) | <0.001 | 27.37 (1.94–386.50) | 0.014 |
| Maternal GBS Bacteriuria | 27/47 (57.5) | 22/220 (10.0) | 12.15 (5.51–26.79) | <0.001 | 8.41 (1.44–49.15) | 0.018 |
| Any IAP 5 | 7/31 (22.6) | 40/104 (38.5) | 0.47 (0.16–1.26) | 0.103 | ||
| IAP ≥4 hours prior to delivery | 5/31 (16.1) | 36/104 (34.6) | 0.36 (0.10–1.08) | 0.074 | ||
| No IAP | 24/31 (77.4) | 64/104 (61.5) | 2.14 (0.80–6.41) | 0.103 | ||
| Late-onset disease | n = 46 | n = 212 | ||||
| Maternal GBS colonization | 28/42 (66.7) | 64/212 (30.2) | 4.63 (2.17–10.11) | <0.001 | 2.44 (0.88–6.79) | 0.088 |
| Prolonged ROM(>18hours) 3 | 2/35 (5.7) | 18/204 (8.8) | 0.63 (0.07–2.83) | 0.746 | ||
| Offensive liquor | 2/38 (5.3) | 3/203 (1.5) | 3.70 (0.30–33.27) | 0.178 | ||
| Maternal GBS Bacteriuria | 18/42 (42.9) | 25/212 (11.8) | 5.61 (2.48–12.46) | <0.001 | 3.49 (1.17–10.40) | 0.025 |
| Any IAP | 1/12 (8.3) | 16/56 (28.6) | 0.23 (0.01–1.84) | 0.269 | ||
| IAP ≥4 hours prior to delivery | 1/12 (8.3) | 10/56 (17.9) | 0.42 (0.01–3.59) | 0.674 | ||
| No IAP | 11/12 (91.7) | 40/56 (71.4) | 4.40 (0.54–201.01) | 0.269 |
1Univariate-OR(95%CI)-calculated odds ratio with 95% confidence using Fischer exact test comparing cases and controls.
2 Multivariate-OR(95%CI)-calculated odds ratio with 95% confidence of disease using conditional logistic regression (For early-onset disease: adjusted for HIV-status, maternal age at delivery, gestational age, maternal GBS colonization, prolonged ROM, offensive liquor, maternal temperature>38, GBS bacteriuria and any intra-partum antibiotics. For late-onset disease: adjusted for HIV-status, maternal age at delivery, gestational age, maternal GBS colonization and GBS bacteriuria).
3 Prolonged ROM (>18 hours)-prolonged rupture of membranes.
4Maternal fever during labor.
5IAP-Intrapartum antibiotic prophylaxis to pregnant women that met risk-based criteria (gestation <37 weeks, PROM and maternal intra-partum fever).