Viral infections trigger exacerbations of cystic fibrosis in adults and children: Figure 1–

Abstract

To the Editors: Cystic fibrosis (CF) is the most common autosomal recessive condition causing disease in western societies, and despite important advances in understanding the disease, patients with CF develop progressive lung disease with recurrent endobronchial infection, eventually becoming chronically colonised with resistant organisms such as Pseudomonas aeruginosa . The clinical course is punctuated by periods of acute worsening of CF lung disease that increase with age and declining lung function, while the frequency of exacerbations is also an independent predictor for decline in lung function and mortality [1]. How and why exacerbations of CF occur is poorly understood. Recent data suggest that exacerbations are not associated with an acquisition of new strains of bacteria, but rather clonal expansion of existing strains [2]. The factors that lead to this imbalance between chronic bacterial infection and host immune response, which then results in CF exacerbations, are unclear. Viral infection may be an important factor that triggers these events. In children with CF, viral respiratory tract infections are associated with exacerbations [3, 4]. In CF a respiratory virus infection superimposed upon chronic bacterial infection potentially could enhance inflammation and shift the balance to favour infection with chronic bacterial pathogens. The aims of this study were to assess the prevalence and aetiology of viral respiratory tract infection in an adult population with CF, compare this to a group of children with CF and assess the impact of this on acute exacerbations of lung disease. We recruited 17 adults (age greater than 17 yrs) and nine children (6–17 yrs) from the CF clinic at John Hunter Hospital, New Lambton, Australia with CF diagnosed by a positive sweat test and CF genotyping. Participants were assessed at baseline and reviewed every 3 months for …