Pulmonary fungal infections

Abstract

This review details some of the advances that have been made in the recent decade in the diagnosis, treatment and epidemiology of pulmonary fungal infections. These advances have occurred because of increasing knowledge regarding the fungal genome, better understanding of the structures of the fungal cell wall and cell membrane and the use of molecular epidemiological techniques. The clinical implications of these advances are more rapid diagnosis and more effective and less toxic antifungal agents. For example, the diagnosis of invasive pulmonary aspergillosis, as well as histoplasmosis and blastomycosis, has improved with the use of easily performed antigen detection systems in serum and bronchoalveolar lavage fluid. Treatment of angioinvasive moulds has improved with the introduction of the new azoles, voriconazole and posaconazole that have broad antifungal activity. Amphotericin B is less frequently used, and when used is often given as lipid formulation to decrease toxicity. The newest agents, the echinocandins, are especially safe as they interfere with the metabolism of the fungal cell wall, a structure not shared with humans cells. Epidemiological advances include the description of the emergence of Cryptococcus gattii in North America and the increase in pulmonary mucormycosis and pneumonia due to Fusarium and Scedosporium species in transplant recipients and patients with haematological malignancies. The emergence of azole resistance among Aspergillus species is especially worrisome and is likely related to increased azole use for treatment of patients, but also to agricultural use of azoles as fungicides in certain countries.