Laboratory Diagnostics of Aspergillosis: Present State and Future Directions

Aspergillosis encompasses a heterogeneous spectrum of diseases caused by filamentous fungi of the genus Aspergillus, ranging from allergic airway disorders and chronic pulmonary infection to rapidly progressive invasive disease. Aspergillus fumigatus is the predominant pathogen worldwide, although other species, including Aspergillus flavus, Aspergillus terreus and cryptic species, contribute to morbidity and may exhibit intrinsic or acquired antifungal resistance. Early and accurate laboratory diagnosis is essential for timely treatment, appropriate antifungal selection, and stewardship. Traditional culture remains foundational, enabling confirmation of viable organisms, species-level identification, and antifungal susceptibility testing, but sensitivity is limited and turnaround times are prolonged. Non-culture approaches—including galactomannan, β-D-glucan, lateral flow assays, PCR, and next-generation sequencing—enhance diagnostic sensitivity, facilitate early detection, and allow identification of resistance-associated mutations. Optimal diagnostic performance is achieved through integrated, multimodal strategies combining laboratory tests with clinical and radiological findings. In invasive disease, concurrent use of biomarkers and molecular assays improves specificity and positive predictive value, while in allergic bronchopulmonary aspergillosis, immunological markers remain central. Future directions include standardised molecular protocols, novel antigenic and host-based biomarkers, and cost-effective, risk-adapted diagnostic algorithms to refine detection, guide therapy, and improve patient outcomes.