OBJECTIVES: Paediatric advisory committee guidelines recommend palivizumab prophylaxis for specific sub-populations of infants at high risk for respiratory syncytial virus (RSV) infection. However, effectiveness of palivizumab may vary across indications and countries. The objective of our study was to determine hospitalization rates for respiratory illness (RIH) and RSV-positive infections (RSVH) following prophylaxis and compare rates found in this study with other world-wide data from published registries. METHODS: Neonatal and demographic data were collected prospectively across 29 national sites as part of an established CAnadian REgistry for SynagiS (CARESS) database from infants who received >1 dose of palivizumab during the 2005-2010 RSV seasons. Respiratory illness (RI) events were documented monthly. RESULTS: The 7699 infants enrolled were premature (<35 completed weeks gestational age, without any underlying medical illnesses; n=5237), had chronic lung disease/bronchopulmonary dysplasia (n=646), hemodynamically significant congenital heart disease (n=766), or had other pre-existing conditions such as neuromuscular impairments, Down syndrome, pulmonary or airway malformations, immunocompromise or cystic fibrosis (n=1050). The overall RIH rate was 6.0%. Premature infants had a significantly lower rate (4.1%) than the other groups (range 8.7% -11.5%; B=-0.912, df=1, p=0.005). The overall RSVH rate was 1.47% with significant differences between groups (range 1.22% - 2.46%; chi2=22.606, df=3, p < 0.0005). Apart from hospital length of stay, morbidities differed significantly across the sub-groups during RSVH including number of ICU admissions and length of stay, number ventilated and duration of intubation, number requiring respiratory support and duration (all p<0.05). CONCLUSIONS: Hospitalization rates for RI events and RSV illness were different across the groups. Comparisons with other registries indicate that RSVH rates are in the lower range overall (range 1.3 -8.1%); however, comparisons are difficult to establish as most studies do not account for the varying lengths of observation that arise because infants are enrolled at different times during the RSV season.
Paes, B. A., Mitchell, I., Li, A., Harimoto, T., & Lanctot, K. L. (2013). Respiratory Syncytial Virus Hospitalizations in the Canadian Registry for Synagis (CARESS). Value in Health, 16(7), A366. https://doi.org/10.1016/j.jval.2013.08.254