1535. Does fecal colonization with Pseudomonas aeruginosa (Ps. aeru) predict infection in recipients of allogeneic hematopoietic stem cell transplantation (allo-HSCT)?
Session: Poster Abstract Session: Infections and Transplantation
Saturday, October 5, 2013
Room: The Moscone Center: Poster Hall C
  • pseudomonas poster idweek.pdf (685.4 kB)
  • Background: Many centers obtain routine surveillance stool cultures (SSC) from allo-HSCT recipients to check for vancomycin resistant enterococcal (VRE) colonization. Our center also performs SSC for Ps. aeru colonization. The aim of this study was to determine the utility of this practice.

    Methods: We conducted a two-year (2010-2012) retrospective review of all patients who underwent allo-HSCT at MD Anderson Cancer Center to determine frequency of colonization and incidence of infection with Ps. aeru. All patients underwent weekly SSC whenever they were hospitalized.

    Results: Of the 794 allo-HSCT, 95 (12%) were identified to have either Ps. aeru infection or positive SSC. Only 58 (7.3%) patients had at least 1 positive SSC with 19 (33%) patients developing Ps. aeru infection subsequently. The overall incidence of Ps. aeru infection in the cohort was 7% (56/794), thus, 37 patients (66%) with infection had a negative SSC. Positive predictive value of SSC was 33% and negative predictive value was 95%. Of the 56 patients with infection, 26 (46%) had pneumonia, 20 (36%) blood stream infection, 8 (14%) urinary tract infection, and 2 (4%) at other sites. The incidence of multi drug resistant (MDR) Ps. aeru in the entire cohort (SSC or infection) was 2.2% (18/794), 12 in the SSC group (7 of which developed a MDR Ps. aeru infection later), and 6 in the infection group that were SSC negative for MDR Ps. aeru. Among the19 patients with positive SSC who went on to develop Ps. aeru infection, 8 (42%) had mismatched resistance patterns. This mismatch suggests a potentially different source for some of the infections. No infection related mortality was observed in the first 30 days after infection.

    Conclusion: The frequency of Ps. aeru colonization on SSC and the development of subsequent infection was low as was the positive predictive value of SSC. Although patients who were not colonized had a low chance of developing Ps. aeru infection, most of the patients who developed Ps. Aeru infection did not have fecal colonization. The value of this SSC for Ps. aeru needs to be revisited at our institution.

    Lior Nesher, M.D., Dimpy Shah, MD, MSPH, Kenneth V. I. Rolston, M.D., Victor E. Mulanovich, MD, Ella Ariza-Heredia, MD and Roy Chemaly, MD, MPH, Infectious Diseases, Infection Control and Employee Health, The University of Texas MD Anderson Cancer Center, Houston, TX


    L. Nesher, None

    D. Shah, None

    K. V. I. Rolston, None

    V. E. Mulanovich, None

    E. Ariza-Heredia, None

    R. Chemaly, None

    Findings in the abstracts are embargoed until 12:01 a.m. PST, Oct. 2nd with the exception of research findings presented at the IDWeek press conferences.