Abstract

Influenza infection is a cause of exacerbations in patients with chronic pulmonary diseases. The aim of this study was to investigate the clinical outcomes and identify risk factors associated with hospitalization and mortality following influenza infection in adult patients with bronchiectasis. Using the Chang Gung Research Database, we identified patients with bronchiectasis and influenza-related infection between 2008 and 2017. The main outcomes were influenza-related hospitalization and in-hospital mortality rate. 865 patients with bronchiectasis and influenza infection were identified. 536 (62%) patients with bronchiectasis were hospitalized for influenza-related infection and 118 (22%) patients had respiratory failure. As compared to the group only seen in clinic, the hospitalization group were older, with more male patients, a lower FEV1, higher BACI and more acute exacerbations in the previous year. Co-infections were evident in 55.6% of hospitalized patients, mainly caused by Pseudomonas aeruginosa (15%), fungus (7%), and Klebsiella pneumoniae (6%). The overall mortality rate was 10.8% and respiratory failure group exhibited significantly higher in-hospital mortality rates (27.1% vs. 6.2%; p < 0.001). Age, BACI and previous exacerbations were independently associated with influenza-related hospitalization. Age, presence of shock and low platelet counts were associated with increased hospital mortality.Influenza virus caused severe exacerbation in bronchiectasis, especially in those older and with high BACI score and with previous exacerbations.A high risk of respiratory failure and mortality were observed in influenza-related hospitalization in bronchiectasis.