Changing epidemiology of systemic fungal infections.

Species of Candida and Aspergillus remain the most common causes of invasive fungal infections, but other yeasts and filamentous fungi are emerging as significant pathogens. Opportunistic yeast-like fungi and moulds such as Zygomycetes, Fusarium spp. and Scedosporium spp. are increasingly being recognised in patient groups such as those with leukaemia and in bone marrow transplant recipients. Recognition of these epidemiological changes is critical to patient care. The key elements in selecting an appropriate antifungal agent are the type of patient (solid-organ or stem-cell transplant), severity of immunosuppression, history of prolonged exposure to antifungal drugs, and knowledge of the genera and species of the infecting pathogen and its typical susceptibility pattern.