1201 Respiratory Syncytial Virus Prophylaxis in Special Populations

Abstract

Background: Infants with existing medical disorders are at high risk for morbidity and mortality from respiratory syncytial virus (RSV) infection. Recent position statements from the Canadian Paediatric Society and American Academy of Pediatrics recommend palivizumab only for specific, pre-existing medical conditions. Objective: To examine the pattern of palivizumab utilization and compliance in infants who meet standard indications for prophylaxis compared to other high risk infants with existing medical disorders within the Canadian Registry Database (CARESS). Methods: A prospective, observational, registry of infants across 29 sites who received at least 1 dose of palivizumab during the 2006-2010 RSV seasons was conducted. Neonatal and demographic data were collected from the parent/caregiver at enrollment. Data on palivizumab utilization, compliance, and outcomes related to respiratory illness (RI) events were collected monthly. Premature infants <35 completed weeks gestational age without medical conditions who met standard approval criteria (Group 1) were compared to other infants at high risk of RI due to underlying medical illnesses who received palivizumab (Group 2). Results: A total of 5832 patients were analyzed (Group 1, n=4880; Group 2, n=952). The two groups were similar in terms of gender (male: 56.4% versus 55.6%; p=0.829). Group 2 infants included Down syndrome (n=192, 20.2%), upper airway anomalies (n=176, 18.5%), pulmonary disorders (n=127, 13.3%), cystic fibrosis (n=117, 12.3%), neuromuscular impairment (n=78, 8.2%), multiple system disorders (n=58, 6.1%), cardiac disorders (n=26, 2.7%), immunocompromise (n=17, 1.8%), and miscellaneous (n=161, 16.9%). From 2006-2010, the proportion of Group 2 infants receiving prophylaxis increased almost 4-fold from 5.6% (69/1224) to 19.1% (462/2413). Overall, Group 2 infants were older at enrollment (10.2+9.2 versus 3.5+3.1 months, p<0.005), had a significantly higher gestational age (35.9+6.0 versus 30.9+5.4 completed weeks, p<0.005) and had significantly higher RI (9.0% versus 4.2%, p<0.0005) and RSV hospitalization (2.35% versus 1.32%, p=0.003) rates. A lower proportion of Group 2 infants were compliant with treatment (69.4% versus 72.8%, p=0.048). There were no serious adverse events directly related to palivizumab. Conclusions: Results imply that infants with underlying medical disorders that are not specifically approved for prophylaxis by advisory bodies and current position statements are at significant risk for hospitalization with respiratory illness and RSV infections.