M044: VIRAL RESPIRATORY TRACT INFECTIONS IN PATIENTS WITH CYSTIC
FIBROSIS
J. Collinson, J. Ashman, E. Cancio, V. Hammersley*,
C. O'Callaghan, K.G. Nicholson*. (Department of Child Health &
*Department of Microbiology, University of Leicester, Leicester,
United Kingdom)
Thirty-eight children with Cystic Fibrosis were studied for 17 months to determine the nature, incidence and effect on respiratory function of symptomatic upper respiratory tract infections (URTIs). Nasal swabs were collected within 72 hours of onset of an URTI and polymerase chain reaction used to identify human picornaviruses and rhinoviruses. In children over 6 years lung function was measured routinely, by spirometry, and repeated at 4 day intervals for 3 weeks following an URTI. Qualitative changes in respiratory flora were observed before and after URTls. Symptomatic URTIs occurred on 147 occasions, giving a median annual incidence of 2.7 per child (range I to 10). Nasal swabs were obtained during 119 episodes; picornaviruses were detected in S I (43%) of these samples. Rhinoviruses, which belong to the picornavirus group, were identified in 21 picomavirus-positive samples, giving a rhinovirus detection rate of 21/119 (18%). Respiratory function data were collected following 57 of 78 (73%) URTIs in 24 children. Significant reductions (p <0.05) from baseline in forced expiatory volume in one second (FEVI) and forced vital capacity (FVC) occurred during the 3 week observation period. Median fall from baseline in FEVI was 13% at 4 days and 10% at 21 days following onset of URTI. Similar changes were observed in FVC. The degree of pulmonary dysfunction observed during picornavirus infections was similar to that observed in non-picornavirus episodes. Nine patients acquired new respiratory bacterial pathogens following URTIs (5 acquired Pseudomonas aeruginosa, 1 Burkholderia cepacia, 3 Haemophilus influenzae). We conclude that picornaviruses and other similar respiratory viruses are significant causes of respiratory morbidity in patients with CF.