Global Guideline on Candidiasis, Part I: Diagnostics

A new guideline for diagnosing and managing candidiasis from the European Confederation for Medical Mycology (ECMM) addresses emerging pathogens such as C auris, and considers application of recently developed diagnostics and newly licensed antifungals.¹ This first of a 2-part report describes guideline diagnostic considerations, with part 2 conveying treatment recommendations.

The guideline was developed by the ECMM in collaboration with the American Society of Miocrobiology (ASM) and the International Society for Human and Animal Mycology (ISHAM). The guideline updates information from previous international recommendations from both the Infectious Diseases Society of America (IDSA) and the European Society of Clinical Microbiology an Infectious Diseases, according to the guideline lead author, Oliver Comely, MD, Institute of Translational Research, Cologne Excellence Cluster on Cellular Stress Response in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany, and colleagues.

The three societies brought together experts from around the world and from multiple disciplines in a global guidance initiative which aims "to improve patient management and outcomes for all forms of candidiasis," Comely and colleagues indicate.They acknowledge, however, "adapting to local contexts based on economic circumstances and antifungal resistance patterns might be needed."

The guideline strongly recommends conventional culture-based methods, while acknowledging limited sensitivity. To enhance the diagnostic yield of blood cultures, drawing greater volumes and incubating higher numbers of bottles is recommended (eg, two to three blood culture sets with 20ml each).To maximize the diagnostic yield of tissue or fluid, the guideline recommends employing microscopy in addition to fungal culture.

Although molecular techniques to detect candidiasis are advancing, the guideline points out that detection is currently restricted to a limited number of Candida spp.It notes that commercial assays are more likely to have undergone extensive analytical clinical validation compared to in-house methods, and so recommends use of commercial assays.

The species of Candida should be identified, the guideline strongly recommends, "to guide empirical management, to detect outbreaks, and for surveillance."

MALDI-TOF mass spectrometry is strongly recommended to provide species-level identification, with biochemical methods moderately recommended in settings where that mass spectrometry is unavailable.PCR assays directly from blood are also recommended, but with moderate strength, given these assays only detect some Candida spp.

Chromogenic agars are strongly recommended for detection of mixed yeast infections—a particular risk for patients after solid organ transplantation and surgery. Chromogenic media are also moderately recommended for presumptive identification.

The guideline also strongly recommends sequencing from culture isolates, particularly in specialized labs, and when MALDI-TOF mass spectrometry or biochemical methods are not available.

The guideline supports the combined use of molecular techniques with biomarker measures. Serum ß-D-glucan (BDG) testing is moderately recommended, with the cautions that a diagnosis of invasive candidiasis or candidemia should not be based on the BDG alone.Additional serology that is moderately recommended as a complimentary diagnostic measure is the combination of mannan antigen and anti-mannan antibody assays.

The guideline emphasizes that these ostsensible biomarkers should only be considered in the diagnosis of candidemia or invasive candidiasis in conjunction with clinical parameters, other biomarkers, or other diagnostic tools.

"There are currently insufficient data to support the use of circulating biomarkers or molecular tests for initiating pre-emptive antifungal treatment," Comely and colleagues caution."Further studies are needed to define the optimal us of BDG testing combined with clinical prediction rules to guide antifungal treatment."

Reference

1.Comely OA, Sprute R, Bassetti M, et al. Global guideline for the diagnosis and management of candidiasis: An initiative of the ECMM in cooperation with ISHAM and ASM. Lancet Infect Dis 2025. Published online February 13, 2025. https://doi.org/10.1016/S1473jjjjjjj-3099(24)00749-7. Accessed February 22, 2025.