Polymerase Chain Reaction (PCR)–Based Diagnostic Assays for Invasive Candidiasis

Abstract

Candidemia and other types of invasive candidiasis are associated with mortality rates as high as 40% despite antifungal therapy. In part, the poor outcomes stem from the inadequacies of diagnostic tests for invasive candidiasis. The current gold standard is blood culture, which is negative in 50% of autopsy-proven cases. As such, development of novel diagnostics is a top priority. Assays for invasive candidiasis based on polymerase chain reaction (PCR) are potentially attractive because of their high sensitivity, rapid turnaround time, capacity for speciation, and ability to quantitate the candidal burden. Research has refined PCR methods and performance parameters to the point that diagnostic assays for invasive candidiasis are approaching the clinic. Overall, optimized PCR assays have sensitivities and specificities for candidemia and proven or probable invasive candidiasis that exceed 90%. Studies are now needed to determine the precise clinical roles of PCR diagnostic assays and their impact on patient outcomes.