1. Department of Otorhinolaryngology, Head and Neck Surgery and Audiology; Rigshospitalet; Denmark
2. Copenhagen CF Centre; Rigshospitalet; Denmark
3. Section of Biostatistics; University of Copenhagen; Denmark
4. Department of Clinical Microbiology; Rigshospitalet; Denmark
5. Paediatric Pulmonary Service; Rigshospitalet, University of Copenhagen; Denmark
6. Institute of Immunology and Microbiology, University of Copenhagen; Denmark