Table 1.
Factors associated with putative clonal transmission of CPE.
| Variable | Clonal-transmission pairs (N = 1451)(%) | Control pairs (N = 1451)(%) | Clonal-transmission pairsa (weighted %) | Control pairsa (weighted %) | Univariable analysisb | Multivariable analysisb | ||
|---|---|---|---|---|---|---|---|---|
| OR (95%CI) | P-value | aOR (95%CI) | P-value | |||||
| Hospital or ward contact | ||||||||
| No hospital nor ward contact | 288 (19.9) | 763 (52.6) | 18.5% | 44.9% | ref | – | ref | – |
| Direct ward contact | 134 (9.2) | 5 (0.3) | 14.5% | 0.5% | 7.55 (5.01–11.4) | <0.0001 | 6.22 (3.89–9.95) | <0.0001 |
| Indirect ward contact | 255 (17.6) | 172 (11.9) | 18.1% | 12.6% | 3.11 (2.08–4.66) | <0.0001 | 2.90 (1.89–4.45) | <0.0001 |
| Direct hospital contact (No ward contact) | 385 (26.5) | 100 (6.9) | 29.0% | 9.1% | 4.99 (3.42–7.29) | <0.0001 | 4.66 (3.20–6.79) | <0.0001 |
| Indirect hospital contact (No ward contact) | 389 (26.8) | 411 (28.3) | 19.9% | 32.9% | 1.65 (1.07–2.53) | 0.022 | 1.62 (1.07–2.47) | 0.023 |
| Discipline contact | ||||||||
| No contact | 1115 (76.8) | 1261 (86.9) | 74.9% | 84.9% | ref | – | ref | – |
| Direct contact | 127 (8.8) | 20 (1.4) | 12.4% | 2.0% | 2.72 (1.91–3.87) | <0.0001 | 1.19 (0.80–1.77) | 0.38 |
| Indirect contact | 209 (14.4) | 170 (11.7) | 12.7% | 13.2% | 1.10 (0.76–1.60) | 0.61 | 0.97 (0.64–1.45) | 0.87 |
| Procedure contact | ||||||||
| No contact | 1438 (99.1) | 1442 (99.4) | 99.6% | 99.0% | ref | – | ref | – |
| Direct contact | 0 | 0 | 0.0% | 0.0% | – | – | – | – |
| Indirect contact | 13 (0.9) | 9 (0.6) | 0.4% | 1.0% | 0.49 (0.06–3.93) | 0.50 | – | – |
| Bacterial species | ||||||||
| Escherichia coli | 283 (19.5) | 593 (40.9) | 18.1% | 39.4% | ref | – | ref | – |
| Klebsiella pneumoniae | 819 (56.4) | 395 (27.2) | 57.5% | 30.4% | 3.05 (2.04–4.55) | <0.0001 | 3.13 (2.14–4.58) | <0.0001 |
| Enterobacter spp | 308 (21.2) | 318 (21.9) | 17.9% | 19.6% | 1.75 (1.14–2.71) | 0.011 | 2.29 (1.46–3.61) | 0.0003 |
| Others | 41 (2.8) | 145 (10.0) | 6.5% | 10.5% | 1.31 (0.65–2.65) | 0.45 | 1.25 (0.59–2.64) | 0.56 |
| Genotypes | ||||||||
| blaKPC | 443 (30.5) | 591 (40.7) | 33.3% | 42.0% | ref | – | ref | – |
| blaNDM | 664 (45.8) | 599 (41.3) | 48.0% | 39.7% | 1.39 (1.01–1.90) | 0.042 | 1.52 (1.04–2.22) | 0.031 |
| blaOXA-type | 321 (22.1) | 153 (10.5) | 14.7% | 10.5% | 1.55 (1.01–2.38) | 0.043 | 1.81 (1.13–2.91) | 0.014 |
| Others | 23 (1.6) | 108 (7.4) | 4.0% | 7.8% | 0.69 (0.31–1.56) | 0.38 | 0.77 (0.34–1.78) | 0.55 |
| Community contactc | ||||||||
| No contact | 1450 (100.0) | 1451 (100.0) | – | – | – | – | – | – |
| Same household | 0 | 0 | – | – | – | – | – | – |
| Same zipcode | 1 (0.0) | 0 | – | – | – | – | – | – |
OR Odds-ratio, aOR Adjusted odds-ratio, Ref Reference, – Not applicable
aTo correct for potential bias from clustering, the prevalence of epidemiologic risk factors were inversely-weighted by a factor of one over the number of case-control pairs with identical source patient and by reducing the sample size to derive standard errors concomitantly.
bUnivariable and multivariable analyses were conducted based on the weighted percentages using conditional logistic regression on matched case-control pairs. The Wald chi-square test was performed for all the risk factors with an α level of 0.05 (two-sided). No adjustment was made for multiple comparisons.
cCommunity contact was excluded from univariable and multivariable analyses as the frequency of exposure was too low.