Advances in the Diagnosis of Invasive Pulmonary Mold Infections: Focus on Diagnostic Performance and Cost-Effectiveness of Diagnostic Tests

Invasive pulmonary mold infections (IPMIs) are critical complications in immunocompromised patients, contributing significantly to morbidity and mortality. Diagnosing pathogens like Aspergillus species (spp.) and the Mucorales remains challenging due to non-specific clinical presentations and the limitations of traditional culture methods. This review provides an up-to-date synopsis of IPMI diagnostic tools, focusing on their diagnostic performance, turnaround time (TAT), and cost-effectiveness. We conducted a narrative review of the current literature regarding clinical evaluation, radiographic findings, invasive diagnostics, and non-invasive assays, including next-generation sequencing (NGS) and volatile organic compounds (VOCs). Chest computerized tomography (CT) remains a vital first step, though classic signs like the “halo” or “reverse halo” are neither sensitive nor specific. Traditional diagnostics are limited by low sensitivity and delayed results. While plasma microbial cell-free DNA (mcfDNA) NGS offers rapid TAT (24–48 h) and high specificity, its suboptimal sensitivity for Aspergillus spp. (<50%) and high cost remain significant barriers. Investigational VOC “breath tests” show promising sensitivity (77–96%) but lack standardization. Future research must prioritize the standardization of non-invasive microbiologic testing modalities, particularly those with rapid TAT such as bedside “breath tests” and high-throughput mcfDNA NGS. Development of clinical algorithms that balance cost-effectiveness with timely pathogen diagnosis based on the patient’s degree of immunosuppression is essential to improve survival in high-risk populations.