Introduction: Isolation of Exophiala species from sputum samples has become increasingly reported in Cystic Fibrosis (CF). However, the clinical significance of Exophiala spp. with regards to the paediatric CF population is unknown.
Methods: A case control study was undertaken to compare CF children with and without chronic Exophiala spp. in their sputum samples. Demographic and clinical data were collected retrospectively for each case from the date of Exophiala isolation and for 12 months preceding isolation. Each case was compared to three age and year-matched controls. To determine the effect of Exophiala on clinical course, patients were then followed for 12 months post isolation.
Results: In total, 27 of 244 eligible paediatric CF patients (11%) isolated Exophiala spp. on more than one occasion. There were no significant differences in the key clinical parameters: spirometry, mean number of intravenous (IV) antibiotic days and body mass index (BMI), between cases and controls (p=0.91, p=0.56 and p=0.63 respectively). A higher proportion of cases isolated Candida spp. (67% vs 21%, p<0.0001) and Aspergillus fumigatus (37% vs 26%, p=0.37). There was no clinically significant difference in spirometry, mean number of IV antibiotic days and BMI in cases pre and post Exophiala spp. isolation. Posaconazole was the only drug used that successfully eradicated Exophiala.
Conclusion: Despite the frequent isolation of Exophiala spp. in this cohort, in most patients it is not associated with significant clinical deterioration. It does however seem to be associated with isolation of other fungi.