Diagnosis of invasive aspergillosis: Recent developments and ongoing challenges

Background: Invasive aspergillosis is an infection with high morbidity and mortality that affects mostly immunocompromised individuals. Early identification and targeted treatment of the infection is essential to improve survival of affected patients. The purpose of our review is to highlight the most recent developments in diagnosis and screening for invasive aspergillosis (IA) along with the challenges associated with the development and validation of novel diagnostic approaches. Methods: Ovid MEDLINE and The Cochrane library were searched for studies that evaluated serologic, molecular and novel methodologies for the diagnosis of IA. Results: Traditional diagnostic approaches, such as histopathology and culture, are still considered the gold standard but lack sufficient sensitivity. Newer serologic techniques, such as galactomannan (GM) and beta-glucan, have already been incorporated into clinical guidelines, but recent evidence suggests that their performance might be limited in certain clinical settings. Molecular methods, such as the Aspergillus spp. polymerase chain reaction (PCR), have not yet found their place in clinical practice mainly due to lack of standardization. Novel methodologies, such as volatile organic compound detection and lateral flow devices, have recently been developed and promise noninvasive and rapid diagnosis of aspergillosis, while diagnostic algorithms that incorporate both GM and PCR have proven to be effective in early randomized trials as screening methods and can reduce the use of antifungal agents. Conclusions: Diagnosis of IA remains challenging. Novel methodologies and the standardization of GM and PCR might provide more reliable diagnostic tools in the future.