1555. Blood Cultures Obtained in Pediatric Neutropenic Patients for Persistent Fever after the Initiation of Broad Spectrum Antibiotics are of Low Diagnostic Yield
Session: Poster Abstract Session: Infections in the Immunocompromised Hosts
Saturday, October 5, 2013
Room: The Moscone Center: Poster Hall C
Posters
  • IDSA Poster Neemann 2013.pdf (618.2 kB)
  • Background: Bacteremia occurs in approximately 10-30% of pediatric oncology patients (POP) with fever and neutropenia (FN), with most positive blood cultures (BC) identified on presentation and prior to the initiation of empiric antibiotics.  Repeat BC are typically drawn daily for persistent or recurrent fevers occurring during empiric antibiotic treatment.  We hypothesize that repeated BC are of low diagnostic yield.

    Methods: We performed a retrospective cohort study of POP admitted with FN in our two institutions from 1/2009 -5/2012.  Patient demographics, primary disease, and treatment-related factors were reviewed and all BC results recorded for every FN episode, through 14 days of empiric antibiotics. BC contaminants including skin flora occurring in a single BC, were excluded from analysis.

    Results: During the study period 117 patients, ages 2 months to 18 years, had 193 FN episodes.  Most were being treated for ALL/lymphoma (67.6%) or sarcomas (32.5%).  In 19 episodes (9.84% [95% CI 6.03-14.95%]) initial BC were positive (eliminated from further evaluation). In 95 episodes, initial BC were negative and subsequent BC were obtained for fever persisting 2-14 days after starting empiric antibiotics.  Among subsequent BC, only 4/421 sets (0.95% [95% CI 0.26-2.41%]) were positive; representing 4/95 FN episodes (4.21% [95% CI 1.16- 10.43%]).  Subsequent positive BC occurred between 3-7 days after initiating antibiotics.  Two of the subsequent bacteremias (1 each VRE, ESBL E.coli) required antibiotic changes; the 2 others were ‘breakthroughs’ from apparently adequate coverage.  All 4 patients survived but overall mortality in all FN episodes was 1.6%.  There were too few bacteremias to analyze for risk factors.

    Conclusion: 9.84% of POP with FN had bacteremia at presentation.  Among those with initial negative blood cultures less than 1% had subsequent positives during persistent FN on days 2-14 of empiric antibiotics.  In 2/4 identified episodes of subsequent bacteremia, a change to antibiotic therapy was warranted, indicating the potential benefit of repeating cultures in these patients. Future directions including multi-center data sets could examine potential patient-level risk factors for bacteremia, and rapid molecular diagnostics could have the potential to reduce blood volume loss while enhancing diagnostic yield.

    Kari Neemann, MD, Univeristy of Nebraska Medical Center, Omaha, NE, Alexandra Brugler Yonts, MD, University of Nebraska Medical Center, Omaha, NE, Kari Simonsen, MD, Pediatrics, Infectious Diseases, University of Nebraska Medical Center, Omaha, NE, Stefanie Lowas, MD, Pediatric Hematology-Oncology, University of Nebraska Medical Center, Omaha, NE; Children's Hospital and Medical Center, Omaha, NE, Fang Qiu, PhD, Biostatistics Department, Nebraska Medical Center, Omaha, NE and Alison Freifeld, MD, Univ of Nebraska, Omaha, NE

    Disclosures:

    K. Neemann, None

    A. Brugler Yonts, None

    K. Simonsen, None

    S. Lowas, None

    F. Qiu, None

    A. Freifeld, None

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