Seasonal influenza infection in vaccinated CF-patients

Background : Annual influenza vaccination is recommended for risk-groups, including CF patients. However influenza vaccine efficacy in CF is not well documented. Aims : To evaluate the impact of influenza infection in well-vaccinated CF patients. Methods : During 4 winter seasons, we prospectively collected nasal secretions by nasal wash for PCR and culture and/or blood for serology, for detection of respiratory viruses in correctly* against influenza vaccinated CF-patients with an acute pulmonary exacerbation. Results : Influenza viruses were detected in a total of 21/170 (12,4%) acute pulmonary exacerbations in 75 CF-patients (median age = 17y7m; gender ratio : F/M = 38/37). Influenza A was found in 19 and influenza B in 2 episodes. In 13/19 influenza A and 1/2 influenza B infections the patients had fever (>38,5°C) and in 8/19 influenza A infections the patient needed oxygen suppletion. For 17/21 influenza infections hospitalisation was necessary with a mean stay of 11,7 days. Conclusions : Influenza infection is frequent in CF-patients, especially in adolescents and adults, despite correct vaccination. Influenza in CF-patients is associated with a high rate of oxygen need and prolonged hospitalisation. *according to ACIP recommendations. A. Malfroot, E. De Wachter, D. Pierard, S. Lauwers. J of Cystic Fibrosis 2005;4(suppl).