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Background

The diagnostic tools currently employed to detect fungal pathogens:

The diagnostic methods employed to diagnose fungal infections at present vary in performance as each type of pathogen has a greater proclivity for being detected by some tests than others. However, microscopy has always been the mainstay as far as diagnosis of fungal infections is concerned. We look forward to improve the diagnostic capabilities of conventional microscopy by enhancing specificity and visibility through the application molecular biology.The following table was compiled from Fungal Infection Thrust.

Detection by Polymerase Chain Reaction

The table above denotes a summary of the techniques used at present to detect the leading fungal pathogens in world. Note that the column titled "DNA detection" is a term that mainly involves the use of the Polymerase Chain Reaction (PCR) to detect pathogens. Although it is touted as a very reliable test, it can only be used in a few types of infections. This is in addition to the other disadvantages it has, such as high cost and more stringent laboratory conditions required which results in this technique not being available to the less developed parts of the world. Finally, the most important disadvantage is that these organisms can be detected EVEN IF THEY ARE NON-VIABLE, as in a post infection stage. The INITIAL AMOUNT of the diagnostic marker (in this case, DNA) can give a clue regarding the stage of the infection but PCR amplifies this amount which means the test can only be used qualitatively. Yes, Real-Time PCR can measure the initial amount as well, but this requires RNA samples which are degraded easily by RNases in the body. Not to mention the need for calibration of the device with a house-keeping gene for each organism.
In addtion to PCR, DNA-hybridization is also employed for diagnosis, but it's extremely labor intensive and involves the use of radio-labelled probes.

Detection by conventional microscopy

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