The role of viral infections in pulmonary exacerbations of patients with non-cystic fibrosis bronchiectasis: A systematic review

Background: Bronchiectasis is a cause of increased morbidity of the respiratory system. Exacerbations among patients with non-CF (cystic fibrosis) bronchiectasis result in reduced pulmonary function and poor quality of life. While the role of bacteria in triggering exac-erbations in patients with non-CF bronchiectasis has been well studied, little is known about viral infections in these patients. We aimed to review the evidence on the role of respiratory viruses in the exacerbations of non-CF bronchiectasis. Methods: Relevant literature was searched on the MEDLINE/PubMed database. Seven studies satisfied the criteria and were included in this review. Results: According to the included articles, respiratory viruses are often identified in exacerbations of patients with non-CF bronchiectasis with the most frequent being human rhinovirus and influenza viruses. When a virus is isolated during an exacerbation patients have more symptoms from the upper respiratory tract. One study showed that detection of Epstein-Barr virus among patients with non-CF bronchiectasis is correlated with faster reduction of pulmonary function and progression of the disease. Conclusion: Viruses seem to have a role in the exacerbation of patients with non-CF bron-chiectasis. However, the exact nature and importance of this role remain elusive. Viruses are also isolated during the stable period of the disease. Further well-designed studies are necessary to clarify this complex issue. (C) 2022 The Japanese Respiratory Society. Published by Elsevier B.V. All rights reserved.