For the severe COVID-19 patients who have more opportunities to be treat with broad-spectrum antibacterial drugs, parenteral nutrition and invasive examinations, or the patients accompanied with prolonged neutropenia and other immune impairment factors, the risk of infection with Candida species may significantly increase [31]. Diagnosis of IC depends on culture methods including culture of blood or other samples collected under sterile conditions which are usually considered as gold standards for IC, and nonculture diagnostic tests including mannan and antimannan IgG tests, C. albicans germ tube antibody (CAGTA), BDG and PCR-based assays, which are now entering clinical practice as adjuncts to cultures [32]. There are mainly two disadvantages about blood culture, on the one hand, the blood culture time is long, because the average positive alarm time is 2–3 days (range 1 to ≥ 7 days), plus identification and susceptibility test duration 4 to 6 days, on the other hand, it is not sensitive than PCR with much lower detection limit when Candida concentration is ≤ 1 CFU/mL and easy to have failure to detect in extremely low concentrations of candidiasis, intermittent candidiasis or deep Candida infection has not entered the blood. Hence, several nonculture diagnostic tests are recommended, but also there is widespread uncertainty about their utility in clinical practice [31]. BDG is a major cell wall constituent of Candida and most pathogenic fungi, excluding Cryptococcus species, Blastomyces species, and Mucorales, which is widely used in clinical and well recommended by detecting serum, but cannot distinguish between Candida and other fungi [25]. Besides, mannan and antimannan IgG tests, CAGTA are employed at many European centers, and higher sensitivity and specificity by a combination with mannan/antimannan assay are observed [33]. There are promising PCR tests, including multiplex-PCR platforms, at the same time, it exists some limitations for a lack of multicenter validation of assay performance, so there are no FDA-cleared PCR assays for Candida, but commercial and in-house tests are widely available. Further, T2 magnetic resonance is also can be used by amplifying and detecting Candida DNA, but its feasibility in early diagnosis of candidemia remains unclear. MALDI-TOF technology is available in more hospitals with the biggest advantage of its promptness taking no more than 5 min to identify a microorganism from isolated colonies, even researchers have developed protocols to identify yeasts directly from positive blood culture bottles within half an hour without performing a subculture [32]. Overall, not only it is necessary to fully realize the benefits of combining culture and nonculture methods, but also, clinicians must take the types of IC, the strengths and limitations of each assay and the context of the clinical setting into account to have a judicious interpretation. Besides, susceptibility test is recommended for all blood-stream and other clinically relevant Candida isolates, especially for C. glabrata or C. parapsilosis.