Laboratory diagnosis and therapy of invasive fungal infections

Abstract

Diagnosing fungal infections remains a problem, particularly in the immunocompromised patient. Symptoms are mostly non-specific and colonization is difficult to distinguish from invasive disease. Existing diagnostic tools often lack sensitivity. Thus, the combination of various diagnostic tools is mandatory to allow earlier diagnosis of systemic fungal infections. Microscopy, culture based methods, antigen detection, and PCR may help to facilitate and accelerate the diagnosis. Galactomannan and glucan are two promising antigens that may be useful for early detection of the infection, but also for therapeutic monitoring. Sensitive and specific PCR assays to detect fungal DNA are an important part of the diagnostic approach. But extensive validation and standardization is strongly needed, before PCR assays can be used in a routine laboratory. The tremendous increase in invasive fungal infections has led to an increased interest in new antifungal agents and the field of antifungal chemotherapy evolved even more rapidly than diagnostic assays. The development of less toxic formulations of amphotericin B, the introduction of improved azoles and the availability of the echinocandins are opening new opportunities for the treatment of fungal infections. However, continuing efforts in the laboratory and well-designed clinical trials are still needed.