Prevalence of allergic bronchopulmonary aspergillosis in cystic fibrosis in an area with a high frequency of atopy

Background: Lower airway colonisation with Aspergillus fumigatus and the complicating hypersensitivity reaction allergic bronchopulmonary aspergillosis (ABPA) is well recognised in patients with cystic fibrosis (CF). There is a wide range in reported prevalence of ABPA in CF. Differences in predisposing factors such as atopy and climatic humidity, but also differences in reporting may in part explain this observation. In the Australian population there is a high frequency of atopy and the climate is relatively humid. Patients and methods: Children and adolescents with CF (n=277) from the CF Clinic, Children's Hospital at Westmead, Sydney, Australia were included in a retrospectively conducted study of Aspergillus colonisation and ABPA (1998-2003). Results: The prevalence of Aspergillus colonised patients increased significantly from 7.4% in 1998 to 18.8% in 2002. No seasonal variation in initial positive Aspergillus culture or in humidity was observed. A total of 13 patients (4.7%) were diagnosed with ABPA over the study period, with a significant increase in prevalence from 0.3% in 1998 to 4.0% in 2002. In addition, the criteria used for reporting ABPA in the study population were in agreement with the recently published diagnostic criteria for ABPA in CF. Conclusions: In spite of a high frequency of atopy and a relatively humid climate in the Sydney area, Aspergillus colonisation and ABPA in CF patients was not disproportionate. Moreover, criteria for reporting of ABPA in this setting was not different from that in the Northern Hemisphere.