LAUSR

Abstract Background The benefit of aerosolized ribavirin (AR) in reducing the risk of progression of RSV infections and RSV-associated mortality in HCT recipients has been recognized, yet there is a paucity of data assessing the use of oral ribavirin (OR) in this patient population. We evaluated outcomes associated with the use of OR compared with AR in HCT recipients. Methods Retrospective review of all HCT recipients with RSV infection treated with OR or AR during three RSV seasons (September 2014 – February 2017). An established immunodeficiency Scoring Index (ISI) was applied to identify patients at high risk for progression and death based on host risk factors. Mortality, progression to lower respiratory infection (LRI), and need for ICU admission was compared among recipients of AR and OR. Results A total of 107 patients were treated with OR (n = 42, 39%) or AR (n = 65, 61%). Recipients of AR and OR were equally likely to be high-risk by ISI scoring (11% vs. 10%, P = 1.00). Fifty-three patients (50%) presented with upper respiratory infection (URI) of whom 13 (25%) progressed to LRI. There was no difference in the rate of progression to LRI between patients who received AR and OR (28% vs. 19%, 
P = 0.53). No difference was found in 30-day mortality rates based on treatment strategy (8% AR vs. 5% OR, P = 0.70). Interestingly, 90-day mortality was found to be significantly lower among patients who received OR vs. AR (20% vs. 5%, P = 0.04). No differences in rates of ICU admission and requirement for mechanical ventilation were found between the two groups. For the 99 inpatients at time of diagnosis, median (interquartile range) length of stay was 7 (5 – 19) days, and was similar for patients on either treatment modality. Eight patients were treated for RSV on an outpatient basis and all received OR. Conclusion HCT patients with RSV had similar outcomes when treated with AR and OR. OR may be a safe and effective alternative to AR for prevention and treatment of RSV in HCT patients with significantly reduced cost. Disclosures R. Chemaly, Gilead: Consultant and Investigator, Consulting fee and Research grant. Ansun: Investigator, Research grant. GSK: Investigator, Research grant.