Developments in the epidemiolgy of invasive fungal infections - implications for the empiric and targeted antifungal therapy

Invasive fungal infections are significant causes of morbidity and mortality in hospitalized, immunocompromised patients. Whereas in hematologic patients aspergilli represent the major problem along with Candida spp., in surgery departments yeast infections are more prevalent. For the empiric as well as the targeted therapy of mould infections with high mortality rates, several antifungals can be given alone or in combination. So far, resistance among aspergilli is uncommon. In yeast infections one has to respect that a relatively large number of causative agents, especially Candida glabrata and C. krusei, can be resistant to azoles, in particular to fluconazole; cross-resistance with other triazoles, such as voriconazole, may occur as well. Coverage of most pathogens involved in life-threatening fungal infections is crucial for empiric treatment. Since caspofungin has a broad spectrum of antifungal activities and is effective even against fungi with azole resistance, this drug should be preferred for initial, empiric therapy of yeast infections, since there are practically no caspofungin resistant strains among clinical isolates. Early start with an adequate empirical antifungal therapy is associated with an improved survival of patients with invasive Candida infections. Once the diagnosis is completed and a susceptibility pattern of the causative agent is available, a targeted therapy can be given respecting pharmacology, side effects and interactions with co-administered drugs.