Program Schedule

Multidrug Resistant Gram Negative Bacteria in a Cohort of Hematopoietic Stem Cell Transplant Recipients

Session: Poster Abstract Session: Transplant Infectious Diseases
Thursday, October 9, 2014
Room: The Pennsylvania Convention Center: IDExpo Hall BC
Background: Bacterial infections are major contributors of morbidity and mortality in hematopoietic stem cell transplant (HSCT) recipients.  Little is known about the risks for, or impact of multidrug resistant gram negative (MDRGN) bacterial infections in this population.

Methods: Patients receiving HSCT at Johns Hopkins Hospital between January and December 2012 were consented into a modified, prospective, cohort study to evaluate infectious complications and followed at 3 month intervals.  Data relating to underlying disease, transplantation, infections, antimicrobials and complications were collected.  Uniquely, the study used standardized definitions to code infectious outcomes.  International standard definitions for acquired antimicrobial resistance from the European Society of Clinical Microbiology and Infectious Diseases were used to classify multidrug resistant bacteria.  The incidence and type of infections were determined, and outcomes were assessed by risk factor analyses evaluating death, performed by logistic regression.

Results: 162 HSCT recipients were enrolled during the study period.  57% were men 93/162. Most had acute myelogenous leukemia (AML) 44/162 (27%) or lymphoma 41/162 (25%).  73% of grafts were bone marrow 118/162.  53% of donors were mismatched, related (haploidentical) 86/162.  65 patients developed 102 bacterial infections; majority 70/102 (69%) were detected as bacteremia.  36 of 65 patients (55%) developed infections caused by gram-negative bacteria (n=46).  MDRGN organisms were recovered in 21/102 (21%) bacterial infections.  E. coli was most common 10/21 (48%).  Overall incidence of MDRGN infections was 21/165 (13%).  Majority of MDRGN caused bacteremia 15/21(71%).  Death occurred in 34/162 (21%) of HSCT recipients.  In multivariable logistic regression, only receipt of an allogeneic transplant (OR 3.8, p=0.047, 95% CI 1.0-13.9) and disease relapse (OR 3.0, p=0.01, 95% CI 1.3-7.0) were independent predictors of death, with MDRGN infection associated with a non-significant trend (OR 2.2, p=0.17, 95% CI 0.7-6.6).

Conclusion: MDRGN infections are common after hematopoietic stem cell transplant and frequently involve the bloodstream, with associated trends to poor outcomes.  More efforts are needed to better characterize risks and outcomes of MDRGN infections in this population.

Richard Larue Jr., MD, MS1, Cristina Royo, MD2, Sehnaz Alp, MD1, Na Lu, MA3, Shmuel Shoham, MD4 and Kieren a. Marr, MD, FIDSA5, (1)Infectious Diseases, Johns Hopkins University, Baltimore, MD, (2)Infectious Diseases, Hospital Universitari de Bellvitge, Barcelona, Spain, (3)Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, (4)The Johns Hopkins Hospital, Baltimore, MD, (5)Medicine & Oncology, The Johns Hopkins Hospital, Baltimore, MD


R. Larue Jr., None

C. Royo, None

S. Alp, None

N. Lu, None

S. Shoham, Astellas: Scientific Advisor, Research support
Merck: Grant Investigator, Grant recipient and Research support
Pfizer: Investigator, Research support
Cubist: Investigator, Research support
Viropharma: Investigator, Research support

K. A. Marr, Astellas: Consultant and Scientific Advisor, Consulting fee
Merck: Consultant, Consulting fee
Pfizer: Consultant, Consulting fee
MycoMed Technologies: Chief Scientific Officer, Licensing agreement or royalty

Findings in the abstracts are embargoed until 12:01 a.m. EDT, Oct. 8th with the exception of research findings presented at the IDWeek press conferences.

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