378. Enterococcal bacteriuria is often overtreated and rarely leads to infectious complications
Session: Poster Abstract Session: Epidemiology - Bacterial Infections
Friday, October 21, 2011
Room: Poster Hall B1
  • 378- enterococcal bacteriuria poster - final.pdf (245.6 kB)
  • Background: Enterococcal bacteriuria, often with resistant organisms, is increasingly common in hospitalized patients.  While urinary tract infection (UTI) requires antibiotics to relieve symptoms, asymptomatic bacteriuria (ABU) is not a clinically significant condition and generally should not be treated.  We hypothesized that enterococcal ABU would be associated with a low rate of complications but would often be inappropriately treated with antibiotics. 

    Methods: We retrospectively reviewed all Enterococcus sp. urine cultures from 9/1/09-11/30/09 at two tertiary care medical centers.  An IDSA-based guideline was used by two reviewers to classify each episode of bacteriuria as UTI or ABU.  P values were calculated using Student’s t-test, chi-square and Fisher’s exact test.

    Results: Thirty random patients from each center were classified by both reviewers with substantial inter-rater agreement (Kappa=0.84).  Enterococcus was isolated from 339 cultures, of which 254 (75%) were vancomycin sensitive.  Of the 339 episodes, 183 were ABU (54%) of which 60 (32.7%) were inappropriately treated with antibiotics; 156 were UTI (46%) of which 23 (14.7%) were undertreated (no antibiotics received).  On univariate analysis, neutropenia, urinary catheterization, having >105 organisms/ml urine, hematuria (≥10 RBC/HPF) and pyuria (≥10 WBC/HPF) were associated with UTI (p ≤ 0.02 for all).  Patients with ABU were more likely to receive inappropriate antibiotics if they had pyuria (OR 4.43, p< 0.0001) or microscopic hematuria (OR 4.02, p= 0.0004).  Pyuria remained significant on multivariate analysis (OR 3.3 [1.49, 7.18], p = 0.003).  Distant infectious complications with Enterococcus were observed within 30 days in 7/156 (4%) UTI, including 2/23 (9%) of untreated UTI.  Only 2/183 (1%) episodes of ABU had distant infectious complications. Six of 9 complications were enterococcal bacteremia, of which 5/6 (83%) occurred after UTI.

    Conclusion: Providers have trouble distinguishing enterococcal UTI from ABU, particularly when the patient has pyuria.  Distant infectious complications were uncommon and more likely to be associated with UTI, especially untreated UTI.

    Subject Category: C. Clinical studies of bacterial infections and antibacterials including sexually transmitted diseases and mycobacterial infections (surveys, epidemiology, and clinical trials)

    Eugene Lin, BS1, Yogesh Bhusal, MD2,3, Deborah Horwitz, BS1, Samuel Shelburne, MD3 and Barbara W. Trautner, MD, PhD1,4, (1)Baylor College of Medicine, Houston, TX, (2)Section of Infectious Diseases, Baylor College of Medicine, Houston, TX, (3)The University of Texas MD Anderson Cancer Center, Houston, TX, (4)Health Services Research & Development Center of Excellence, Michael E. DeBakey Veterans Affairs Medical Center, Houston, TX


    E. Lin, None

    Y. Bhusal, None

    D. Horwitz, None

    S. Shelburne, None

    B. W. Trautner, None

    Findings in the abstracts are embargoed until 12:01 a.m. EST Thursday, Oct. 20 with the exception of research findings presented at IDSA press conferences.