444. Predictors of Catheter Related Gram Negative Bacteremia (CR-GNB) in Cancer Patients
Session: Poster Session: Hospital-acquired and Transplant Infections
Friday, October 30, 2009: 12:00 AM
Room: Poster Hall A
Background: Catheter related blood stream infection (CRBSI) is most commonly caused by Gram positive cocci, followed by Gram negative bacilli (GNB). Current risk factors and characteristics of the latter are not well understood. We conducted a retrospective study in patients with GNB to determine which factors may predict CR-GNB among cancers patient with GNB bacteremia and a central venous catheter (CVC.)
Methods: We reviewed records of all patients at our institution with bacteremia caused by GNB that occurred between July 2005 to December 2006. Cases were classified as CRBSI according to CDC’s criteria, using the ratio of the colony forming units (CFU) of bacteria in blood cultures from the CVC and periphery and the differential time to positivity. This study describes the clinical and microbiological features of CR-GNB vs non-CR-GNB.
Results: We analyzed 170 patients. Seventy six cases had CR-GNB and 94 cases had non-CR-GNB. There were no significant differences in age, gender, fever, mucositis and duration of catheterization between groups. Exposure to antibiotic was significantly higher in non-CR-GNB (p<0.01). In bivariate analysis, polymicrobial bacteremia, Stenotrophomonas bacteremia and having more than 1000 colony-forming units (CFU) of bacteria were more common among CRBSI cases while E coli bacteremia, hematologic malignancy and neutropenia were more likely associated with non-CR-GNB. In multivariate analysis, polymicrobial bacteremia (Odds Ratio [OR] 2.79, 95% confidence interval [CI] 1.04-7.49, p = 0.042,), Stenothrophomonas bacteremia (OR 4.17 ,95%CI 1.03 -16.81, p = 0.045), more than 1000 CFU from CVC blood sample (OR 4.59, 95% CI 1.92-10.96, p < 0.01), and non-neutropenia (OR 0.19, 95%CI 0.09-0.42, p < 0.01) remained associated with CRBSI.
Conclusions: In multivariate analysis, polymicrobial bacteremia, Stenotrephomonas bacteremia, and > 1000 CFU bacterial load were suggestive of CR-GNB, whereas neutropenia appeared to be associated with a non-catheter source (OR 0.19, p<0.01).
Javier Cairo, MD, MPH, University of Texas - MD Anderson, Houston, TX, Bruno Granwehr, MD, The University of Texas M. D. Anderson Cancer Center, Houston, TX, Ray Hachem, MD, Infectious Diseases, Infection Control & Employee Health, University of Texas MD Anderson Cancer Center, Houston, TX, Issam Raad, MD, Gopikishan Rangaraj, MD, University of Texas, M.D. Anderson Cancer Center, Houston, TX and  J. Cairo, None..
G. Rangaraj, None..
R. Hachem, None..
B. Granwehr, None. 
I. I. Raad,
Cook, Inc. Role(s): Consultant, Research Relationship, Other, Royalties related to technology on which Dr. Raad is an inventor/co-inventor, Consultant, Research Relationship, Other, Royalties related to technology on which Dr. Raad is an inventor/co-inventor, Consultant, Research Relationship, Other, Royalties related to technology on which Dr. Raad is an inventor/co-inventor, Received: Educational Grant, Licensing Agreement or Royalty, Consulting Fee.

Disclosures:

J. Cairo, None

B. Granwehr, None

R. Hachem, None

I. Raad, None

G. Rangaraj, None