BACKGROUND: RSV causes considerable morbidity and mortality in children. In 
cystic fibrosis (CF) viral infections are associated with worsening respiratory 
symptoms and bacterial colonization. Palivizumab is effective in reducing RSV 
hospitalization in high risk patient groups. Evidence regarding its 
effectiveness and safety in CF is inconclusive. CF screening in N. Ireland 
enabled timely palivizumab prophylaxis, becoming routine in 2002.
OBJECTIVES: To determine the effect of palivizumab on RSV-related 
hospitalization and compare lung function and bacterial colonization at age 6 
years for those born pre- and post-introduction of palivizumab prophylaxis.
METHODS: A retrospective audit was conducted for all patients diagnosed with CF 
during the period from 1997 to 2007 inclusive. RSV-related hospitalization, time 
to Pseudomonas aeruginosa (PA) 1st isolate, lung function and growth parameters 
were recorded. Comparisons were made for outcomes pre- and post-introduction of 
routine palivizumab administration in 2002. A cost evaluation was also 
performed.
RESULTS: Ninety-two children were included; 47 pre- and 45 post-palivizumab 
introduction. The overall RSV-positive hospitalization rate was 13%. The 
relative risk of RSV infection in palivizumab non-recipients versus recipients 
was 4.78 (95%CI: 1.1-20.7), P = 0.027. Notably, PA 1st isolate was significantly 
earlier in the palivizumab recipient cohort versus non-recipient cohort (median 
57 vs. 96 months, P < 0.025) with a relative risk of 2.5. Chronic PA infection 
at 6 years remained low in both groups, with similar lung function and growth 
parameters. Total costs were calculated at £96,127 ($151,880) for the 
non-recipient cohort versus £137,954 ($217,967) for the recipient cohort.
CONCLUSION: Palivizumab was effective in reducing RSV-related hospitalization 
infection in CF patients. Surprisingly, we found a significantly earlier time to 
1st isolate of PA in palivizumab recipients which we could not explain by 
altered or improved diagnostic tests.