The role of respiratory viruses in adult patients with cystic fibrosis receiving intravenous antibiotics for a pulmonary exacerbation

BackgroundRespiratory viruses have become increasingly recognised as important agents in pulmonary exacerbations in infants and children with CF. The aim of this study was to determine the prevalence of respiratory viruses during acute pulmonary exacerbations in adults and compare the severity of these exacerbations with non-viral associated exacerbations.MethodsThis was a retrospective case control study. Viral throat swabs were taken from all patients presenting with an acute pulmonary exacerbation requiring intravenous antibiotic treatment over a 12 month period.ResultsThere were 432 pulmonary exacerbations in 180 adults. A positive viral PCR in 42 exacerbations indicated a prevalence of 9.7%. The commonest virus isolated was rhinovirus (n = 29, 69%) with influenza A/H1N1 in seven patients (16.7%). Exacerbations associated with a positive viral PCR had a greater fall in lung function at presentation with higher levels of inflammatory markers. They received more days of intravenous antibiotics, showed less response to treatment and had a shorter time to next pulmonary exacerbation compared to matched controls.ConclusionViral associated pulmonary exacerbations in adults with CF are associated with more severe pulmonary involvement and respond less well to standard treatment.