A new commercially available multiplex real-time PCR assay―MucorGenius® shows good sensitivity for detecting pulmonary mucormycosis in bronchoalveolar lavage fluid (BALF) samples. An Austrian study evaluating its diagnostic performance, conducted by Prattes et al., found that all four cases diagnosed with mucormycosis had a positive BALF MucorGenius® PCR and 24% of 25 possible IMI cases were positive on MucorGenius® PCR. In addition, positive Mucorales PCR results (2.5%) were observed among patients with proven/probable invasive pulmonary aspergillosis (IPA) and 19 Mucorales PCR—positive samples were observed amongst patients without any routinely diagnosed IMIs.
The findings from this study demonstrate the usefulness of MucorGenius® PCR assay in diagnosing mucormycosis among individuals with possible IMIs and patients with proven/probable IPA. Given that direct microscopy and culture are very insensitive, this is helpful. Overall, 32 positive MucorGenius® results were observed compared with four cases diagnosed with proven or probable pulmonary mucormycosis. However, more studies would be needed to validate its specificity, given that clinical data were not provided for the unconfirmed cases detected as PCR-positive – they may reflect transient colonisation, even in this population.
The added value of applying Mucorales PCR testing to BALF samples in patients suspected to have IMIs cannot be overemphasised. Given that a significant proportion of mucormycosis cases are diagnosed postmortem, a positive BALF-Mucorales PCR can enable premortem diagnosis of pulmonary mucormycosis. In addition, an early targeted treatment can be achieved, which is the major factor for predicting survival.
