“…Participants were advised to contact investigators as soon as they developed symptoms of a cold or a worsening of their chest disease and reviewed in 48 h. Acute exacerbations were defined when any four of the 12 items of the Fuchs' criteria were present [5]. At each visit, spontaneous sputum was sent for quantitative microbiology [6] and two throat swabs were performed using a semi-nested PCR for influenza A and B, respiratory syncytial virus (RSV), rhinovirus (RV), coronavirus, human metapneumovirus, parainfluenza 1, 2 and 3, and adenovirus [7] and RV were sequenced [8]. When data were normally distributed, differences were analysed using a non-paired t-test and, when not normally distributed, a non-parametric equivalent.…”