Table 1.
Characteristics of the Study Cohort Stratified by Site of Infection
| Variable | Number (%) of Patients | ||||
|---|---|---|---|---|---|
| Infection Type | |||||
| Bacteremiaa (N = 140) | HABP (N = 21) | VABP (N = 20) | cUTI/AP (N = 75) | All (N = 256) | |
| Demographic Variables | |||||
| Male sex | 87 (62.1%) | 15 (71.4%) | 13 (65.0%) | 35 (46.7%) | 150 (58.6%) |
| Age, years, mean (SD) | 62.3 (15.6) | 60.3 (16.9) | 55.5 (17.2) | 62.7 (16.8) | 61.7 (16.2) |
| Country of Residence | |||||
| Greece | 11 (7.9%) | 0 | 4 (20.0%) | 0 | 15 (5.9%) |
| Italy | 67 (47.9%) | 9 (42.9%) | 6 (30.0%) | 12 (16.0%) | 94 (36.7%) |
| United Kingdom | 12 (8.6%) | 1 (4.8%) | 0 | 2 (2.7%) | 15 (5.9%) |
| United States | 50 (35.7%) | 11 (52.4%) | 10 (50.0%) | 61 (81.3%) | 132 (51.6%) |
| Patient-Specific Risk Factors | |||||
| Prior culture positive for CRE | 74 (52.9%) | 3 (14.3%) | 7 (35.0%) | 15 (20.0%) | 99 (38.7%) |
| Duration of hospitalization, mean (SD)b,j | 27.5 (40.1) | 22.7 (24.6) | 17.5 (22.6) | 13.2 (20.2) | 22.2 (33.5) |
| Immunocompromised conditionc | 36 (25.7%) | 7 (33.3%) | 6 (30.0%) | 18 (24.6%) | 67 (26.2%) |
| Presence of neutropeniad | 14 (10.0%) | 0 | 1 (5.0%) | 2 (2.7%) | 17 (6.6%) |
| Prior transplantatione | 24 (17.1%) | 3 (14.3%) | 4 (20.0%) | 10 (13.3%) | 41 (16.0%) |
| Renal | 5 (3.6%) | 1 (4.8%) | 0 | 2 (2.7%) | 8 (3.1%) |
| Hepatic | 6 (4.3%) | 2 (9.5%) | 2 (10.0%) | 5 (6.7%) | 15 (5.9%) |
| Heart/lung | 2 (1.4%) | 0 | 0 | 0 | 2 (0.8%) |
| Other | 13 (9.3%) | 0 | 2 (10.0%) | 4 (5.3%) | 19 (7.4%) |
| Comorbidities | |||||
| Diabetes mellitus | 41 (29.3%) | 4 (19.0%) | 5 (25.0%) | 22 (29.3%) | 72 (28.1%) |
| Heart failurej | 26 (18.6%) | 6 (28.6%) | 6 (30.0%) | 16 (21.3%) | 54 (21.1%) |
| Chronic renal insufficiencyf | 47 (33.6%) | 5 (23.8%) | 5 (25.0%) | 27 (36.0%) | 84 (32.8%) |
| Requirement for dialysis | 32 (22.9%) | 2 (9.5%) | 9 (45.0%) | 8 (10.7%) | 51 (19.9%) |
| Solid tumor | 34 (24.3%) | 7 (33.3%) | 3 (15.0%) | 12 (16.0%) | 56 (21.9%) |
| Hematologic malignancy | 22 (15.7%) | 3 (14.3%) | 1 (5.0%) | 8 (10.7%) | 34 (13.3%) |
| Concurrent bacteremia | NA* | 5 (23.8%) | 5 (25%) | 16 (23.5%) | NA |
| Charlson Comorbidity Index, median (IQR) | 3.0 (2.0–5.0) | 4.0 (2.0–7.0) | 3.0 (3.0–4.5) | 3.0 (2.0–6.0) | 3.0 (2.0–5.0) |
| Empiric therapy without in vitro activityg | 80 (57.1%) | 17 (81%) | 16 (80%) | 60 (80.0%) | 173 (67.6%) |
| Presentation with severe sepsish,j | 52 (37.1%) | 6 (28.6%) | 11 (55.0%) | 15 (20.0%) | 84 (32.8%) |
| Presentation with septic shocki | 47 (33.6%) | 6 (28.6%) | 8 (40.0%) | 14 (18.7%) | 75 (29.3%) |
| APACHE II score, mean (SD) | 22.1 (10.5) | 18.6 (9.5) | 21.4 (6.3) | 23.5 (9.0) | 21.9 (9.7) |
Abbreviations: AP, acute pyelonephritis; APACHE, Acute Physiologic Assessment and Chronic Health Evaluation; CI, confidence interval; CRE, carbapenem-resistant Enterobacteriaceae; cUTI, complicated urinary tract infection; DIC, disseminated intravascular coagulation; HABP, hospital-acquired bacterial pneumonia; IQR, interquartile range; IV, intervenous; NA, not applicable; OR, odds ratio; SBP, systolic blood pressure; SD, standard deviation; VABP, ventilator-associated bacterial pneumonia.
aSource of bacteremia was IV catheter in 47 of 140 (33.6%) patients, unknown in 23 of 140 (16.4%) patients, cUTI/AP in 12 of 140 (8.6%) patients, HABP in 5 of 140 (3.6%) patients, VABP in 5 of 140 (3.6%) patients, and “other” in 48 of 140 (34.3%) patients.
bDuration of hospitalization before index CRE infection.
cImmunocompromised condition included hematologic malignancy, prior bone marrow transplant, or received immunosuppressive therapy, such as cancer chemotherapy, antirejection medications for transplantation, or long-term (≥2 weeks) use of systemic steroids.
dNeutropenia was defined as <500 neutrophils/mm3.
eAlthough a patient may have had 2 or more different types of transplantations, the same patient was only counted once in the prior transplantations category.
fChronic renal insufficiency was defined as moderate-to-severe renal disease.
gEmpiric therapy without in vitro activity was defined as empiric antimicrobial therapy that did not contain at least 1 agent with in vitro activity against the index CRE pathogen according to microbiologic data entered.
hSevere sepsis was defined as infection associated with any of the following: hypotension (SBP ≤90 mmHg or a decrease in SBP of ≥40 mmHg from baseline [if known] unresponsive to fluid challenge), hypothermia (core temperature <35.6°C or <96.1°F), or DIC as evidenced by prothrombin time or partial thromboplastin time 2× the upper limit of normal or platelets less than 50% of the lower limit of normal [13].
iSeptic shock (a subset of severe sepsis) was defined as infection associated with hypotension (SBP ≤90 mmHg or a decrease in SBP of ≥40 mmHg from baseline [if known] unresponsive to fluid challenge) [13].
jPrior duration of hospitalization greater than or equal to 14 days (OR, 1.89; 95% CI, 1.04–3.46), history of heart failure (OR, 2.41; 95% CI, 1.20–4.82), and presentation with severe sepsis (OR, 2.72; 95% CI, 1.50–4.96) were associated with increased likelihood of 28-day mortality on multivariate analysis. See Supplemental Table E.