To determine the differences in number of respiratory syncytial virus (RSV) hospitalizations and outcomes in infants 290/7-346/7 weeks' gestational age (wGA) the season before (season 1 [S1]; 2013-2014) and after (season 2 [S2]; 2014-2015) implementation of the 2014 American Academy of Pediatrics revised guidance for palivizumab prophylaxis.Study design
Children <12 months of age hospitalized with RSV infection were identified by the International Classification of Diseases, Ninth Revision codes and virology reports. Clinical, outcome data, palivizumab eligibility, and hospital charges were compared among infants 29-34 wGA in S1 vs S2.Results
Of 1063 RSV hospitalizations in infants <12 months old, 7.1% (34/482) in S1 and 9.8% (57/581) in S2 occurred in 290/7-346/7 wGA infants. On the other hand, 29-34 wGA infants who were <6 months old constituted 3.5% (17/482) of RSV hospitalizations in S1 vs 7.1% (41/581) in S2 (P = .01). Among 290/7-346/7 wGA healthy infants who were <3 months old, oxygen administration (40.0% vs 78.9%; P = .05), pediatric intensive care unit admission (30.0% vs 68.4%; P = .04), mechanical ventilation (10.0% vs 52.6%; P = .04), duration of hospitalization (1.8 vs 8.8 days; P = .04), and hospital charges ($19 686 vs $30 662; P = .03) significantly increased in S2 vs S1. No differences in morbidity were observed in premature infants who were 3 to <6 and 6 to <12 months between seasons. Palivizumab eligibility decreased from 32.3% in S1 to 1.8% in S2 (P < .001). One infant died in each season.Conclusions
In the year following implementation of the 2014 palivizumab prophylaxis guidance, there was an increase in RSV hospitalizations and associated morbidity among 29-34 wGA infants of younger chronological age.