Poct in clinical mycology

Abstract

Point-of-care testing (POCT) in diagnostic mycology is less well-defined than for pathogens of wide public health impact. Fungal infections are relatively uncommon and largely affect specific host groups: the immunocompromised and critically ill. Early diagnosis and therapy has been shown to improve patient outcomes in invasive candidiasis including candidaemia. Commercial PCR-based platforms are available to directly detect <i>Candida</i> in blood cultures but also in whole blood up to 4 days prior to the ‘flagging' of positive cultures. However systematic evaluation of impact of this technology on outcomes has not been undertaken. Detection of <i>Aspergillus</i> DNA and galactomannan in blood and other body fluids has good potential for early diagnosis of invasive aspergillosis. In resource-limited countries and settings where cryptococcosis is prevalent, detection of serum cryptococcal antigen (CRAG) is sensitive for early diagnosis, including in asymptomatic patients; early treatment reduces mortality. The CRAG lateral flow assay is one such tool to detect CRAG in serum, urine and saliva with high sensitivity and specificity. Therapeutic drug monitoring of drug levels is increasingly important. Not only do voriconazole and posaconazole blood levels have relevance, but blood fluconazole levels should also be measured, especially in severely ill patients to ensure meaningful dosing.