#53 Morbidity and Mortality Associated with Respiratory Syncytial Virus (RSV) Among Pediatric Hematopoietic Cell (HCT) Recipients: Preliminary Results from a Multi-Site U.S. Study.

Abstract

Abstract Background RSV is the most common lower respiratory tract infection (LRTI) among children. Serious adverse outcomes are more likely among immunocompromised patients, including progression to pneumonia, respiratory failure, and increased mortality rates. We present interim analysis results from a multi-site study to characterize morbidity and mortality associated with RSV infection among pediatric HCT patients. Method Pediatric (< 18 years old at transplant) HCT recipients from 10 U.S. transplant centers part of the Pediatric Infectious Diseases Transplant Network (PIDTRAN) who underwent HCT between 2010 and 2019 and were RSV positive during pre-transplant conditioning or within 365 days of HCT were identified from medical records. Demographics, underlying condition, and clinical characteristics were abstracted and entered in an electronic REDCap survey. Descriptive statistics were used to characterize the clinical course and outcomes of RSV infection. Results In total, 108 HCT patients were eligible with 108 (96%) reporting 1 case of RSV within 365 days of transplant and 5 (4%) reported 2 episodes resulting in 113 RSV episodes included in the analysis. Approximately half (53.7%) were male, 53 (49.1%) were white/Caucasian, with a median age of 7 years at the time of RSV diagnosis. The majority only received 1 HCT (84%) prior to RSV diagnosis. The most common HCT was allogeneic type (77.8%), 63 (59%) received myeloablative conditioning, and 23 (22.3%) were t-cell depleted. Just over one third (38%) had received systemic steroids in the 2 weeks prior to RSV diagnosis. Among the 113 episodes, 3 (2.7%) received palivizumab and 34 (30%) received IVIG in the 4 weeks prior to RSV diagnosis. One fourth (25.6%) were hospitalized due to RSV and 13 (11.5%) were diagnosed with LRTI at presentation and 3 (2.7%) progressed to LRTI after initial diagnosis of a URTI. Fifteen (13.3%) received at least 4 hours of oxygen support each day (at least one day), including 2 (13.3%) requiring mechanical ventilation. A quarter (24.8%) were treated with ribavirin, 10 (9%) received IVIG, and 15 (13.4%) received palivizumab for treatment of RSV. Seven (6.3%) deaths related to RSV were reported. Conclusion Preliminary results from this continuing multi-site study demonstrate RSV is an ongoing concern among HCT recipients with 1 in 10 developing LRTI and a quarter requiring hospitalization. These data help our understanding of RSV infections in this population and inform future prospective study designs to better define RSV risk as well as help address optimal prophylaxis and treatment strategies for HCT recipients at risk for severe illness.