Prevalence, Risk Factors, and Outcomes of Bacteremia Caused by Carbapenem-resistant Enterobacteriaceae in Neutropenic Patients with Hematologic Malignancies
Methods: In order to assess the prevalence, risk factors, and outcomes of CRE bacteremia in neutropenic patients with hematologic malignancies, we reviewed all bloodstream infections (BSIs) from 2008-2012 in this population at New York-Presbyterian Hospital/Weill Cornell and Memorial Sloan Kettering Cancer Center and conducted a case-control study. For each case of CRE BSI, three controls matched by study site and year were randomly selected among BSIs caused by other pathogens.
Results: CRE caused 4.8% of Gram-negative bacteremias and 2.1% of all BSIs. Of the 42 episodes of CRE bacteremia, 31 (74%) were in patients with acute leukemia, 15 (36%) were in allogeneic stem cell transplant recipients, and 26 (62%) were in patients without prior carbapenem exposure. Independent risk factors for CRE bacteremia were exposure to β-lactam/β-lactamase inhibitors (BL-BLI; odds ratio [OR] = 3.7; P = 0.01) and trimethoprim-sulfamethoxazole (TMP-SMX; OR 6.0; P = 0.007), glucocorticoid use (OR 5.3; P = 0.001), and having a prior culture that grew CRE (OR 19.2; P = 0.01). Patients with CRE bacteremia were less likely than controls to receive active empirical therapy (14% vs. 56%, P < 0.001) and had longer delays until receipt of active therapy (median hours: 52 vs. 5, P < 0.001). They also had higher 30-day (51% vs. 25%, P = 0.001) and BSI-related (49% vs. 16%, P < 0.001) mortality rates, with a median of 3 days from bacteremia onset until death. The six cases of CRE bacteremia that received active empirical therapy had a lower 30-day mortality rate than that of the 36 others that did not (17% vs. 58%; P = 0.09).
Conclusion: CRE are emerging as lethal causes of bacteremia in neutropenic patients with hematologic malignancies. Exposures to BL-BLI, TMP-SMX, and glucocorticoids and having a prior culture that grew CRE are risk factors for CRE bacteremia in this population. New strategies are needed to shorten the delay until administration of CRE-active agents and mitigate this emerging threat.
M. J. Satlin,
K. C. Ma, None
Z. Gedrimaite, None
T. J. Walsh, None
S. K. Seo, None