Table 1.

Overview of key diagnostics

Test		Advantages	Limitations
Microscopy		Fast turnaround46 High sensitivity when using fluorescent brightener staining6,51	Inability to identify species6
Blood culture		Species identification19 Susceptibility pattern	Slow turnaround21,53 Timing of blood collection, during the course of infection19 Necessary to culture a large blood volume (40 mL) in aerobic flasks53 When Candida density is low (<1 cfu/mL), blood cultures can result in false negatives Cultures may become negative after initiating antifungal therapy5
Sterile site cultures		Species identification Susceptibility pattern	May require invasive procedures19 Cultures may become negative after initiating antifungal therapy5 Long incubation required for optimal performance (3 days)6 For intra-abdominal candidiasis, lack of specificity to differentiate infection from colonisation35
Mannan antigen/anti-mannan antibodies		Early detection22,54 Useful to rule out infection22	Serial determinations required22 Lower utility in immunosuppred hosts52 May not distinguish between past and acute infections19 Sensitivity varies regarding Candida species (better for C. albicans, N. glabrata and C. tropicalis)54 Decreased specificity if Candida colonisation is present54 Low positive predictive value, potentially leading to antifungals overuse Limited by low serum concentrations and rapid bloodstream clearance19 Not species-specific, requiring further tests to identify the fungus46 No data on susceptibility pattern Not approved by FDA19 Not universally available
CAGTA		Fast turnaround and low cost5 Could be used to detect whether candidaemia originated in a catheter or deep organs55	May not distinguish between past and acute infections19 Limited by low serum concentrations and rapid bloodstream clearance19 Sensitivity varies according to Candida species (lower for C. tropicalis)5,19 Not species-specific, requiring further tests to identify the fungus46 Low positive predictive value, potentially leading to antifungals overuse No data on susceptibility pattern Not approved by FDA19 Not universally available
BDG		Early detection22 Useful to rule out infection22	Serial determinations required22 Lower utility in patients with haematological disease22 and immunosuppred hosts52 Sensitivity varies according to Candida species (lower for C. parapsilosis)19 May not distinguish between past and acute infections19 Not species-specific, requiring further tests to identify the fungus45 Low positive predictive value, potentially leading to antifungal overuse No data on susceptibility pattern Not universally available
Nucleic acid amplification-based methods	PCR	Early detection58 Monitoring of persistence or resolution of infection4	Mostly developed in-house or commercially19 Frequently performed in reference laboratories limiting the advantage of short turnaround time45 Data interpretation impaired by test heterogeneity19 Not universally available
	T2Candida	Early detection19,59 Automated molecular diagnosis49,59 May detect candidaemia missed by cultures during empirical or pre-emptive AF therapy4 Improved performance in neutropenic patients4	Costs associated with the test46 Limited to some Candida species (C. albicans/C. tropicalis, N. glabrata/P. kudriavzevii, and C. parapsilosis, groupings that are based on typical antifungal susceptibility pattern)49,59 No data on susceptibility pattern59 Not universally available

AF, antifungal; BDG, β-D-glucan; CAGTA, C. albicans germ tube antibody; cfu, colony forming units; FDA, Food and Drug Administration; PCR, polymerase chain reaction.