Early and accurate diagnosis of invasive fungal infections (IFI) in cancer patients is a major challenge, but progress is being made in many areas. Identification of patients at risk of various IFIs is improving, and the nature of risk factors for various IFIs is being better defined (for example, aspergillosis in various organ transplant patients). Conventional tests are still the cornerstone of diagnosis, either singly (direct examination, culture, cytology, histopathology) or combined with non-conventional tests. Several non-conventional tests are being standardized and evaluated in various clinical settings. Both molecular-based tests (PCR, molecular identification of fungi upon culture), and non-molecular tests (antigens, fungal metabolites) are available -often only in a research setting, however. Fungal PCR tests, either panfungal or genus-specific (Candida, Aspergillus), followed by species-specific probes, have been applied to various clinical samples (blood, tissue, BAL), allowing in some studies diagnosis of an IFI earlier than from clinical clues or a conventional approach. Serial Aspergillus galactomannan, and, to a lesser degree, Candida mannan-antimannan, determinations in appropriate at-risk patients can help to select individuals for more complex or invasive diagnostic procedures, or to initiate preemptive antifungal therapy. The systematic use of new definition criteria to define IFIs will contribute to the clarification of the role of these tests at the bedside. Their broad application in the clinical setting will depend on the timing of results in relation to the onset of the disease, and whether they alter clinical management of IFIs. The use of non-conventional tests (mainly used as screening procedures in well-defined at-risk patients) to trigger conventional diagnostic procedures such as tissue biopsies or CT, will hopefully allow an early diagnosis of serious fungal infections. This should lead to higher therapeutic success rates and better prognoses.
Full conference title:
42nd ICAAC Abstracts, American Society for Microbiology, September 27 - 30, 2002, San Diego, CA
- ICAAC 42nd