Fungal infections in patients with cystic fibrosis

Abstract

Current US Cystic Fibrosis Foundation (CFF) Registry data indicates an approximate doubling of prevalence of fungi being detected in the sputum of patients with cystic fibrosis (CF), probably due to a better understanding of the disease and the way in which it is managed. The introduction of new antibiotics and the way in which they are used – in double or triple therapy and as well as in antibiotic cycling – has helped address the requirement to control chronic Gram-negative infections in CF. However, this has inadvertently created a niche for the colonization and proliferation of fungi in the CF lung. The ability to detect and isolate fungi in the sputum of CF patients is important due to the emerging significance of these organisms, particularly in relation to: (i) allergic bronchopulmonary aspergillosis (ABPA); (ii) post-transplant fungaemia; and (iii) chronic colonization/infection (bronchitis). Recent data has indicated that ABPA affects approximately 1–15% of CF patients and is associated with an accelerated decline in lung function. Most of the mycological aetiology of this condition is due to Aspergillus fumigatus and other Aspergillus spp, although other fungi have been reported. In addition, patients who have undergone lung transplantation are at increased risk of opportunistic fungal infection, such as invasive pulmonary aspergilloma and other invasive mycoses, due to the immunosuppression of the host. This review summarizes the important fungal pathogens in CF, namely Aspergillus spp., as well as the emerging fungi, including Scedosporium apiospermum and Exophiala dermatitidis and discusses the various conventional and molecular methods of detection and identification.