Up-date on Diagnostic Strategies of Invasive Aspergillosis

Invasive fungal infections are a major cause of morbidity and mortality in immunosuppressed patients with fatality rates ranging from 30 % to 80 % in neutropenic patients. This results at least partly in difficulties obtaining a reliable and early diagnosis, followed by the fact that clinical symptoms are unspecific and of very limited use. Conventional methods may be difficult and are often delayed. Serological tests like the galactomannan enzyme immunoassay are presently most promising for diagnosing invasive aspergillosis, however, sensitivity and specificity vary within the studies. This review reflects the current situation of diagnosing invasive fungal infections with a special focus on how to best diagnose Aspergillus-related infections (e.g., culture, microscopy, imaging techniques, CT-guided biopsies). Promising molecular techniques under development will be discussed and their potential for routine diagnostic applications (e.g. lateral flow device, polymerase chain reaction [PCR]-based assays, rolling circle amplification [RCA], loop-mediated amplification [LAMP], nucleic acid sequence-based amplification [NASBA]). A summary is given on commercial assays (e.g., Platelia Aspergillus®, Fungitell®, in situ hybridization, immunohistochemisty) and their purposes as screening tools and/or diagnostic tools. This review gives a future outlook on how to best diagnose Aspergillus infections.