Nucleic Acid Tools for Invasive Fungal Disease Diagnosis

Purpose of Review This review has incorporated the knowledge and experience of the leads of each of the laboratory working parties of the fungal PCR initiative in order to provide up-to-date information on the performance and developments of PCR methods for the detection of fungi that commonly cause invasive fungal disease (IFD). Recent Findings Molecular diagnosis of IFD enhances the current repertoire of mycological investigations. Providing superior sensitivity and turn-around-time over classical approaches, yet maintaining the benefits of classical tests (e.g. species level identification and identifying resistance). Standardization for Aspergillus PCR is almost complete; the recent release of commercial PCR assays for a wide range fungi (Aspergillus, Candida, Pneumocystis, Mucorales and Pan-fungal) and availability of external quality control schemes (e.g. Quality Control of Molecular Diagnostics for Aspergillus, Candida, Pneumocystis) means that fungal PCR testing is robust and ready for use, globally. Further work is needed to ascertain the utility of PCR in routine practice and to determine whether combining it with other biomarkers is an optimal strategy. PCR for detecting Mucorales sp. and on tissue, together with direct antifungal resistance detection in body fluids, may increase its diagnostic value across the board. This and the ability to diagnose Pneumocystis pneumonia and invasive candidiasis would go a long way towards attaining the long-held ambition of medical mycology to provide a comprehensive range of tests that can be relied upon to diagnose, at least, the common IFD. In short, PCR has a clear future and is close to achieving its full potential in our laboratories.