Outcomes for and risk factors associated with vancomycin-resistant Enterococcus faecalis and vancomycin-resistant Enterococcus faecium bacteremia in cancer patients.
OBJECTIVE
Vancomycin-resistant enterococci (VRE) are a major cause of nosocomial infection. We sought to compare vancomycin-resistant (VR) Enterococcus faecalis bacteremia and VR Enterococcus faecium bacteremia in cancer patients with respect to risk factors, clinical presentation, microbiological characteristics, antimicrobial therapy, and outcomes.


METHODS
We identified 210 cancer patients with VRE bacteremia who had been treated between January 1996 and December 2004; 16 of these 210 had VR E. faecalis bacteremia and were matched with 32 patients with VR E. faecium bacteremia and 32 control patients. A retrospective review of medical records was conducted.


RESULTS
Logistic regression analysis showed that, compared with VR E. faecalis bacteremia, VR E. faecium bacteremia was associated with a worse clinical response to therapy (odds ratio [OR], 0.3 [95% confidence interval (CI), 0.07-0.98]; P=.046) and a higher overall mortality rate (OR, 8.3 [95% CI, 1.9-35.3]; P=.004), but the VRE-related mortality rate did not show a statistically significant difference (OR, 6.8 [95% CI, 0.7-61.8]; P=.09). Compared with control patients, patients with VR E. faecalis bacteremia were more likely to have received an aminoglycoside in the 30 days before the onset of bacteremia (OR, 5.8 [95% CI, 1.2-27.6]; P=.03), whereas patients with VR E. faecium bacteremia were more likely to have received a carbapenem in the 30 days before the onset of bacteremia (OR, 11.7 [95% CI, 3.6-38.6]; P<.001). In a multivariate model that compared patients with VR E. faecium bacteremia and control patients, predictors of mortality included acute renal failure on presentation (OR, 15.1 [95% CI, 2.3-99.2]; P=.004) and VR E. faecium bacteremia (OR, 11 [95% CI, 2.7-45.1]; P<.001). No difference in outcomes was found between patients with VR E. faecalis bacteremia and control patients.


CONCLUSIONS
VR E. faecium bacteremia in cancer patients was associated with a poorer outcome than was VR E. faecalis bacteremia. Recent receipt of carbapenem therapy was an independent risk factor for VR E. faecium bacteremia, and recent receipt of aminoglycoside therapy was independent risk factor for E. faecalis bacteremia.
Ghanem
G
G
Department of Infectious Diseases, The University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030, USA.
Hachem
R
R
Jiang
Y
Y
Chemaly
R F
RF
Raad
I
I
D000328:Adult; D000368:Aged; D000617:Aminoglycosides / Q000009:adverse effects; D016470:Bacteremia / Q000150:complications / Q000453:epidemiology / Q000382:microbiology / Q000401:mortality*; D015780:Carbapenems / Q000009:adverse effects; D016022:Case-Control Studies; D003428:Cross Infection / Q000188:drug therapy / Q000401:mortality; D013293:Enterococcus faecalis / Q000187:drug effects*; D016984:Enterococcus faecium / Q000187:drug effects*; D005260:Female; D016908:Gram-Positive Bacterial Infections / Q000188:drug therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000150:complications; D012189:Retrospective Studies; D012307:Risk Factors; D013781:Texas / Q000453:epidemiology; D020713:Vancomycin Resistance
D000617:Aminoglycosides; D015780:Carbapenems