Open Access Highly Accessed Research article

Time to blood culture positivity as a predictor of clinical outcome in patients with Candida albicans bloodstream infection

Cintia Zoya Nunes1, Alexandre R Marra12*, Michael B Edmond3, Elivane da Silva Victor2 and Carlos Alberto Pires Pereira1

Author Affiliations

1 Infectious Diseases Division, Universidade Federal de São Paulo (UNIFESP), São Paulo, Brazil

2 Division of Medical Practice, Hospital Israelita Albert Einstein, São Paulo, Brazil

3 Department of Internal Medicine, Virginia Commonwealth, University School of Medicine, Richmond, Virginia, USA

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BMC Infectious Diseases 2013, 13:486  doi:10.1186/1471-2334-13-486

Published: 20 October 2013

Abstract

Background

Few studies have assessed the time to blood culture positivity as a predictor of clinical outcome in fungal bloodstream infections (BSIs). The purpose of this study was to evaluate the time to positivity (TTP) of blood cultures in patients with Candida albicans BSIs and to assess its impact on clinical outcome.

Methods

A historical cohort study with 89 adults patients with C. albicans BSIs. TTP was defined as the time between the start of incubation and the time that the automated alert signal indicating growth in the culture bottle sounded.

Results

Patients with BSIs and TTPs of culture of ≤36 h (n=39) and >36 h (n=50) were compared. Septic shock occurred in 46.2% of patients with TTPs of ≤36 h and in 40.0% of patients with TTP of >36 h (p=0.56). A central venous catheter source was more common with a BSI TTP of ≤36 h (p=0.04). Univariate analyis revealed that APACHE II score≥20 at BSI onset, the development of at least one organ system failure (respiratory, cardiovascular, renal, hematologic, or hepatic), SOFA at BSI onset, SAPS II at BSI onset, and time to positivity were associated with death. By using logistic regression analysis, the only independent predictor of death was time to positivity (1.04; 95% CI, 1.0-1.1, p=0.035), with the chance of the patient with C. albicans BSI dying increasing 4.0% every hour prior to culture positivity.

Conclusion

A longer time to positivity was associated with a higher mortality for Candida albicans BSIs; therefore, initiating empiric treatment with antifungals may improve outcomes.

Keywords:
Candida; Bloodstream infection; Time to positivity; Antifungal therapy