Fungitell Test Interpretation and ICD-10 Coding
Understanding Fungitell Test Limitations
- The Fungitell assay has a sensitivity of 75-80% and specificity of approximately 80% for invasive candidiasis, with significant limitations in its ability to detect specific fungal pathogens or infection sites 1, 2
- The test has a high rate of false positives, particularly in ICU patients, those on hemodialysis, receiving albumin/immunoglobulin products, or on certain antibiotics like piperacillin-tazobactam 4, 5
- Positive results can occur with multiple fungal pathogens, including Candida, Aspergillus, and Pneumocystis jirovecii 1, 2
Appropriate ICD-10 Coding Strategy
- The Infectious Diseases Society of America recommends coding the specific fungal infection diagnosed, such as B37.7 for Candida sepsis or B44.0 for invasive pulmonary aspergillosis 1, 6
- The American College of Chest Physicians suggests using codes for signs/symptoms or suspected infection, such as R50.9 for fever or R65.20 for severe sepsis without septic shock 3, 4
Critical Coding Pitfalls to Avoid
- The Centers for Disease Control and Prevention advises against coding a fungal infection diagnosis based solely on a positive Fungitell test without supporting clinical, microbiological, or histopathological evidence 1, 2
- The test should be incorporated into clinical decision-making alongside blood or tissue cultures, clinical risk factors, radiographic findings, and additional biomarkers 1, 2, 4, 6