Fungal diagnostic stewardship in immunocompromised populations: a focus on molds and dimorphic fungi

SUMMARY Invasive fungal diseases cause severe illness and death in immunocompromised patients. Antifungal use is increasingly common, as is fungal diagnostic testing. However, these efforts have not been guided by traditional stewardship efforts akin to those used for bacterial infections. Fungal diagnostic stewardship can have a significant impact on the care of vulnerable patients, including decreasing unnecessary testing while increasing appropriate testing and improving testing strategies to reduce diagnostic errors. In this review, we discuss the most frequently used fungal diagnostic assays for molds and dimorphic fungal infections, their diagnostic performance for these organisms in immunocompromised hosts, and strategies to improve diagnostic stewardship and ultimately patient outcomes.