Table 3.
Bacterial Culture Results by Case-Control Status
| Cases (n = 360) |
Controls (n = 360) |
χ2 test | |||
|---|---|---|---|---|---|
| n | (%) | n | (%) | ||
| Any isolate cultured | 195 | (54.2) | 124 | (34.4) | <0.001 |
| Number of organisms cultured | |||||
| 0 | 165 | (45.8) | 236 | (65.6) | — |
| 1 | 125 | (34.7) | 96 | (26.7) | <0.001 |
| 2 | 66 | (18.3) | 24 | (6.7) | <0.001 |
| 3 | 4 | (1.1) | 4 | (1.1) | 0.62 |
| Type of isolate cultured* | |||||
| None | 165 | (45.8) | 236 | (65.6) | — |
| Commensal only | 171 | (47.5) | 117 | (32.5) | <0.001 |
| Pathogenic +/− commensal | 24 | (6.7) | 7 | (1.9) | <0.001 |
| Organisms | |||||
| CNS | 110 | (30.6) | 69 | (19.2) | <0.001 |
| Corynebacterium spp. | 89 | (24.7) | 42 | (11.7) | <0.001 |
| Viridans group streptococci | 35 | (9.7) | 32 | (8.9) | 0.70 |
| Bacillus spp. | 8 | (2.2) | 8 | (2.2) | 1.0 |
| Haemophilus influenzae, B | 9 | (2.5) | 0 | (0.0) | 0.003 |
| Streptococcus pneumoniae | 7 | (1.9) | 1 | (0.3) | 0.03 |
| Escherichia coli | 3 | (0.8) | 0 | (0.0) | 0.08 |
| Neisseria spp. | 3 | (0.8) | 0 | (0.0) | 0.08 |
| Staphylococcus aureus | 2 | (0.6) | 0 | (0.0) | 0.16 |
| Aeromonas hydrophilia | 0 | (0.0) | 2 | (0.6) | 0.16 |
| Fungus, mould | 0 | (0.0) | 2 | (0.6) | 0.16 |
| Gram negative rods (other) | 1 | (0.3) | 1 | (0.3) | 1.0 |
| Actinomyces | 1 | (0.3) | 0 | (0.0) | 0.32 |
| Enterobacter cloacae | 1 | (0.3) | 0 | (0.0) | 0.32 |
| Gram-negative rods, non-Lactose fermenting | 1 | (0.3) | 0 | (0.0) | 0.32 |
| Klebsiella spp. | 0 | (0.0) | 1 | (0.3) | 0.32 |
*
Commensal organisms include CNS, Corynebacterium spp., and Viridans group streptococci.