A prompt and accurate diagnosis is key to effective management of invasive mould infections such as invasive aspergillosis and mucormycosis. Yet identifying pathogens in time continues to be a challenge.^1,2

Traditional methods for diagnosing invasive mould infections rely on culture of sputum or bronchoalveolar lavage (BAL) samples, along with histopathologic detection of fungus on specimens. However, culture methods can be slow and have a low positive predictive value, particularly in non-hematological patients or those already on antifungal therapy.^8-10
 

Read about traditional methods for identifying invasive fungal infections, including molecular and imaging techniques, here.


INSTRUMENTS FOR IDENTIFICATION

Novel techniques may be able to accelerate the diagnostic process:^8-10

• Galactomannan detection in serum or BAL is a widespread tool for diagnosing invasive aspergillosis. Sensitivity and specificity is less than 85%, and can be further reduced if a patient is under antifungal prophylaxis or therapy.
• Multiple PCR techniques target Aspergillus spp. or Aspergillus fumigatus, but these methods have not yet been standardized. New approaches have recently been developed, including:

• Detection of volatile organic compounds in exhaled breath by gas chromatography/mass spectrometry is an emerging technique that is already used in the management of diseases such as asthma and COPD, and is currently a research-application for fungal infections.

Regardless of novel techniques becoming available, traditional direct microscopy of a sample with calcofluor white remains the most rapid tool. Despite offering low sensitivity and requiring a high level of clinical microbiologist expertise, this method can detect invasive mould infections in less than 15 minutes.⁸
 

Existing options do come with limitations, but they’re a step in the right direction. When paired with prompt and appropriate therapy, these techniques will help to further our fight against resistance.