41964. Differential Time to Positivity between Coagulase-Negative Staphylococci Bacteremia and Contamination
Session: Poster Abstract Session: Medical Student Poster Session
Friday, October 4, 2013
Room: Yerba Buena Ballrooms
  • ID Week 2013 Shinichiro Morioka.pdf (155.3 kB)
  • Background: Coagulase-negative staphylococci (CoNS) are the most common contaminants of blood cultures and it is sometimes difficult for physicians to determine their clinical significance. We aimed to distinguish CoNS bacteremia from contamination by using differential time to positivity.

    Methods: We retrospectively reviewed 175 sets of blood cultures drawn from 95 patients that yielded CoNS from October 2011 to March 2013. We considered as contamination if one of the CoNS was identified in only one of more than two sets of blood cultures drawn simultaneously. Single-set samples, polymicrobials and the cases with anti-CoNS antimicrobial use were excluded from our study. We investigated the time to positivity and other clinical findings in 78 sets with CoNS bacteremia in comparison with 57 sets with CoNS contamination.

    Results: There were no statistical difference between two groups in age, sex, vital signs, white blood cell count, central venous catheter or implanted port placement, length of hospital stay and death during hospitalization. Ninety-two percent (35 out of 38) of the patients with bacteremia received vancomycin therapy. Eighty-two percent (31 out of 38) of them were diagnosed with catheter-related bloodstream infection and most of them had removal of central venous catheter or implanted port. The median time to positivity in bacteremia group was significantly shorter than that in contamination group (14 hours 45 minutes and 20 hours 31 minutes, respectively, p = 0.0157).

    Conclusion: Differential time to positivity could be helpful to distinguish CoNS bacteremia from contamination.

    Shinichiro Morioka1, Hanako Kurai, MD2, Yuko Yamauchi3, Naoyuki Tsutsumi, MD4 and Ichiro Kawamura, MD4, (1)Infectious Diseases, Shizuoka Cancer Center, Shizuoka, Japan, (2)Div. of Infectious Disease, Shizuoka Cancer Center Hospital, Shizuoka, Japan, (3)Shizuoka Cancer Center, Shizuoka, Japan, (4)Div. of infectious diseases, Shizuoka Cancer Center, Shizuoka, Japan


    S. Morioka, None

    H. Kurai, None

    Y. Yamauchi, None

    N. Tsutsumi, None

    I. Kawamura, None

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