The Challenge of Obtaining Qualitative Bacterial Cultures in Non-expectorating Cystic Fibrosis Patients

Accurate identification of lower respiratory tract pathogens is standard of care in the management of CF patients and it is therefore recommended to perform regular bacterial cultures, at least once a year, but some even recommend monthly cultures. This can be done through different methods, of which sputum and bronchoalveolar lavage (BAL) are the gold standard. However, BAL is an invasive method, not designated to repeat monthly. Therefore, the diagnosis of lower respiratory tract infections can be challenging in the non-expectorating CF patient. Other methods, such as induced sputum (IS), cough swabs and nasal swabs, have been developed to obtain bacterial cultures in these patients. Studies have investigated the reliability of these different sampling methods, however, with controversial conclusions.