There are a number of factors that independently predict exacerbation frequency in bronchiectasis, including gastro-oesophageal reflux, comorbid cardiovascular disease, co-existent asthma, age, duration of symptoms, FEV1 ≤50% predicted, ≥3 bronchiectatic lobes and airway colonization with P. aeruginosa.19–22 Research has also demonstrated that COPD, sputum neutrophil elastase activity, previous viral infection and high airway bacterial loads are associated with more exacerbations in bronchiectasis.23–26. Here, ELANE is linked to viral infectious disease.