What are the key diagnostic criteria for invasive candidiasis in immunocompromised patients?

Key diagnostic criteria for invasive candidiasis in immunocompromised patients include a combination of clinical suspicion, risk factors, microbiological evidence, and supportive imaging or biomarker findings.

Clinically, invasive candidiasis should be suspected in immunocompromised patients presenting with persistent fever despite broad-spectrum antibiotics, signs of sepsis, or organ dysfunction, especially in the presence of known risk factors such as neutropenia, central venous catheters, recent surgery, or prolonged ICU stay NICE NG51.

Microbiological confirmation is essential and involves isolation of Candida species from normally sterile sites such as blood cultures or tissue biopsies. Blood culture remains the gold standard, although sensitivity is limited, and repeated cultures may be necessary NICE NG51. Non-culture-based diagnostics, including detection of Candida mannan antigen, anti-mannan antibodies, and β-D-glucan assays, can support diagnosis but should be interpreted in the clinical context due to variable specificity Cornely et al. 2025.

Imaging studies, such as ultrasound, CT, or MRI, are important to identify deep-seated candidiasis or organ involvement, particularly in hepatosplenic candidiasis or abscess formation Alby-Laurent et al. 2022Cornely et al. 2025.

Recent guidelines emphasize a multidisciplinary approach combining clinical risk assessment, microbiological data, and imaging to improve diagnostic accuracy in immunocompromised hosts NICE NG51. Emerging literature highlights the role of molecular diagnostics and rapid antigen detection assays to enhance early diagnosis, especially in high-risk populations such as haematology patients Posteraro et al. 2025.