The Role of Viral Infection in Acute Exacerbations of Non-cystic Fibrosis Bronchiectasis in Adults

Bronchiectasis is a chronic airway disease characterised by a vicious cycle of persistent bacterial colonization,inflammation and progressive tissue destruction.Patients with bronchiectasis frequently developed acute exacerbations characterised by acute worsening requiring changes in concomitant use of medication,with attendant adverse effects on their morbidity and health-related quality of life. The detailed pathogenesis of exacerbations of bronchiectasis, however, remains poorly understood.

Recent data suggested that airway infection and inflammation are important drivers of exacerbations,therefore the imbalance between chronic bacterial infection and host immune response may result in bronchiectasis exacerbations. Viral infection may be an important factor that leads to this events.It has been established that respiratory viruses are mainly responsible for the exacerbations of other chronic respiratory diseases, i.e. asthma, COPD and cystic fibosis. However, the data regarding prospective studies that sought to investigate the roles of viruses in acute exacerbation of bronchiectasis are lacking. Furthermore,the associations between viruses and bacteria during exacerbation need to be assessed. This study targets at indentifying the frenquency of common viral infections in adults with non-cystic fibrosis bronchiectasis and may shed light on the effects they have on clinical parameters,i.e. the length of exacerbated symptom to recovery,lung function, pulmonary inflammation, bacterial load and quality of life.