Time to Positivity as a Diagnostic Tool for Catheter-Related Candidemia: A Species-Specific Analysis

ABSTRACT Background Early identification of the source of candidemia is critical for catheter management. Time to positivity (TTP) is an accessible marker of catheter-related bloodstream infection in bacteremia, but its role in candidemia remains unclear. We evaluated the ability of TTP to predict catheter-related candidemia across major species and compared its performance with differential time to positivity (DTP). Methods Single-center retrospective study assessing the diagnostic utility and optimal TTP cut-offs for catheter-related candidemia. Predictors of catheter-related source were analyzed using multivariable logistic regression. Results Among 544 episodes, 407 were analyzed. In C. albicans (n=133) and C. parapsilosis (n=100), TTP differed significantly by source. In C. albicans, TTP ≤27h predicted catheter-related candidemia (sensitivity 71.8%, specificity 70.2%, Positive Predictive Value (PPV) 50.0%, Negative Predictive Value (NPV) 85.7%) and was the only independent predictor (OR 5.1 [2.1–12.1], p<0.001). In C. parapsilosis, TTP ≤35h showed sensitivity 77.5%, specificity 51.7%, PPV 51.7%, NPV 77.5%, and remained independently associated (OR 3.1 [1.2–8.0], p=0.017). Although DTP ≥2h was more frequent in catheter-related candidemia by C. parapsilosis, the TTP ≤35h was the strongest predictor. Conclusions TTP outperformed DTP in identifying catheter-related sources in C. albicans and C. parapsilosis candidemia and may support timely catheter management.