A clinical predictive model of candidaemia by Candida auris in previously colonized critically ill patients.

OBJECTIVES: Candida auris is an emerging multidrug-resistant fungus that has been associated with nosocomial outbreaks with high rates of mortality and transmission. The aim of this study was to perform a retrospective cohort analysis of risk factors and to build a scoring method for estimating the risk of candidaemia in colonized critically ill patients. METHODS: We performed a retrospective observational cohort study of patients aged ≥15 years colonized by C. auris in the 3-year period between March 2016 and March 2019. Epidemiological, clinical, laboratory and microbiological data were collected. We developed a predictive model for candidaemia using elastic net multivariable logistic regression techniques, assessed its discriminative capacity, and internally validated it using bootstrap resampling. RESULTS: Two-hundred and six patients were enrolled in the cohort for derivation and internal validation. Thirty-seven out of 206 patients developed candidaemia. Total parenteral nutrition was the foremost risk factor (adjusted OR 3.73); previous surgery (adjusted OR 1.03), sepsis (adjusted OR 1.75), previous exposure to antifungal agents (adjusted OR 1.17), arterial catheters (adjusted OR 1.46), central venous catheters (adjusted OR 1.21), presence of advanced chronic kidney disease (adjusted OR 1.35) and multifocal colonization (adjusted OR of unifocal colonization 0.46) were proven to be independent predictors of candidaemia in our cohort. The corresponding area under the curve (AUC) of the elastic net regularized predictive model was 0.89 (95%CI 0.826; 0.951). After performing the internal validation by generating 500 bootstrap replications, the model still showed great accuracy, with a resulting AUC of 0.84. CONCLUSION: Our study provides evidence on the independent predisposing factors for candidaemia. It may help predict its estimated risk and may identify a high-risk population that could benefit from early or prophylactic antifungal treatment after external validation in other cohorts.

Update on the diagnosis of invasive fungal infection.

The number of patients at risk of suffering invasive fungal infection (IFI) is increasing. Because of its high mortality, new rapid and accurate diagnostic tools are needed. Last advances in invasive candidiasis diagnosis comprise Peptide Nucleic Acid Fluorescent In-Situ Hybridization (PNA-FISH), direct MALDI-TOF or multiplex acid nucleic testing. While all of them rely in positive blood cultures, T2Candida uses PCR coupled with T2Magnetic resonance detection directly in whole blood, allowing detection of 1-3 UFC/mL of Candida in about four hours. Beyond galactomannan (GM), novelties in IFI caused by molds include the international standardization of PCR techniques, with several commercial kits available. A combination of GM and PCR appears to be a good diagnostic strategy for invasive aspergillosis. PCR coupled to electrospray ionization/mass spectrometry and detection of volatile organic compounds in exhaled air by gas chromatography/mass spectrometry are other promising approaches to IFI diagnostic that still need to be validated.