Clinical impact of time to positivity for Candida species on mortality in patients with candidaemia

Abstract

Objectives: The time to positivity (TIP) of blood cultures is associated with the microbial load in the blood and prognosis in patients with bloodstream infections caused by various bacterial species. However, relevant information about the TIP for Candida species in candidaemia is limited. We investigated the clinical impact of the TIP on mortality in patients with candidaemia. Methods: All consecutive patients >= 18 years of age with candidaemia between January 2006 and July 2012 were included. The demographics, clinical and microbiological characteristics, antifungal treatment and outcomes of the patients were collected retrospectively. Results:A total of 152 patients were identified. The overall mortality rate at 6 weeks was 53%. The median TIP for Candida isolates was 27 h (IQR 19-37 h). A TIP of <= 24 h was significantly related to a higher mortality rate (P=0.021). In a multivariate Cox regression analysis, the Charlson comorbidity index value [adjusted hazard ratio (HR) 1.15, 95% CI 1.02-1.29, P=0.018], sequential organ failure assessment score (adjusted HR 1.23, 95% CI 1.13-1.34, P<0.001), TIP <= 24 h (adjusted HR 2.74, 95% CI 1.51-4.97, P=0.001), timing of appropriate antifungal therapy >72 h (adjusted HR 2.38,95% CI 1.26-4.51, P=0.008) and persistent candidaemia (adjusted HR 2,50, 95% CI 1.33-4.72, P=0.005) were independently associated with the 6 week mortality rate. Conclusions: A short TIP (<= 24 h) for Candida species was independently associated with increased mortality in patients with candidaemia. Additional studies on the relevance of the TIP to clinical outcome in patients with candidaemia are needed.