Utility of real-time PCR in the diagnosis of invasive aspergillosis

Invasive aspergillosis (IA) is a life-threatening fungal infection primarily affecting immunocompromised individuals, including transplant recipients and those receiving chemotherapy. Beyond these traditional high-risk groups, patients with viral pneumonia or hepatic dysfunction are also increasingly recognized as emerging risk factors. However, the diagnosis of IA remains clinically complex, as both symptomatic presentations and radiological findings are non-specific and unreliable. Conventional diagnostic methods often suffer from prolonged turnaround time and are low in sensitivity. This study was conducted to evaluate the diagnostic utility of a commercial Real-time PCR assay compared to conventional mycological methods (microscopy and culture) for the detection of Invasive Aspergillosis in clinical specimens.

A cross sectional study was conducted on 50 patients who were clinically suspected of Invasive Aspergillosis(IA) infection. Samples were processed for microscopy and culture. Real-time PCR was performed in these samples using commercially available kits.

Among the diagnostic modalities evaluated Real time PCR demonstrated highest positivity rate (56%). Relative to culture, Real-time PCR achieved 92.31% sensitivity and 83.33% specificity, with a positive predictive value (PPV) of 85.71%, a negative predictive value (NPV) of 90.91%. Diagnostic accuracy was 88%, and an area under the curve (AUC) of 0.883 (95% CI: 0.793-0.973).

These results suggest that Real-time PCR is a reliable diagnostic modality which is highly sensitive and has robust negative predictive value, offering significant utility for early detection of Invasive Aspergillosis.