Influenza A(H1N1)pdm09 and Cystic Fibrosis Lung Disease: A Systematic Meta-Analysis

Background: To systematically assess the literature published on the clinical impact of Influenza A(H1N1)pdm09 on cystic fibrosis (CF) patients. Methods: An online search in PUBMED database was conducted. Original articles on CF patients with Influenza A(H1N1)pdm09 infection were included. We analyzed incidence, symptoms, clinical course and treatment. Results: Four surveys with a total of 202 CF patients infected by Influenza A(H1N1)pdm09 were included. The meta-analysis showed that hospitalisation rates were higher in CF patients compared to the general population. While general disease symptoms were comparable, the clinical course was more severe and case fatality rate (CFR) was higher in CF patients compared to asthmatics and the general population. Conclusions: Evidence so far suggests that CF patients infected with Influenza A(H1N1)pdm09 show increased morbidity and a higher CFR compared to patients with other chronic respiratory diseases and healthy controls. Particularly, CF patients with advanced stage disease seem to be more susceptible to severe lung disease. Accordingly, early antiviral and antibiotic treatment strategies are essential in CF patients. Preventive measures, including vaccination as well as hygiene measures during the influenza season, should be reinforced and improved in CF patients.