title: Respiratory syncytial virus infection-associated hospitalization in adults: a retrospective cohort study.
abstract: BACKGROUND
  Once considered primarily a pediatric concern, respiratory syncytial virus (RSV) infection is gaining recognition as a cause of significant morbidity and mortality in adults. A better understanding of RSV epidemiology and disease in adults is needed to guide patient management and to assess the need for prophylaxis, vaccines, and treatments.
  
  
  METHODS
  We conducted a retrospective cohort study of adults admitted to four hospitals in Toronto, Canada, between September 2012 and June 2013 with RSV identified by a qualitative real-time reverse-transcriptase polymerase chain reaction assay in nasopharyngeal swab or bronchoscopy specimens. Main outcomes were hospital length of stay, need for intensive care unit (ICU) or mechanical ventilation, and all-cause mortality.
  
  
  RESULTS
  Eighty-six patients were identified as requiring hospitalization for RSV infection (56% female). Median age was 74 (range 19-102) years; 29 (34%) were < 65 years. Eighty-three (97%) had underlying chronic medical conditions; 27 (31%) were immunosuppressed, and 10 (12%) known smokers. The most common symptoms and signs were cough in 73 (85%), shortness of breath in 68 (79%), sputum production in 54 (63%), weakness in 43 (50%), fever in 41 (48%), and wheezing in 33 (38%). Lower respiratory tract complications occurred in 45 (52%), cardiovascular complications occurred in 19 (22%), and possible co-pathogens were identified in 11 (13%). Sixty-seven (78%) were treated with antibiotics and 31 (36%) with anti-influenza therapy. Thirteen (15%) required ICU care and 8 (9%) required mechanical ventilation. Five (6%) died during hospitalization. Need for ICU and mechanical ventilation were associated with mortality (P ≤ 0.02). Median hospital length of stay was 6 days (mean 10.8 days).
  
  
  CONCLUSIONS
  RSV infection is associated with the need for extended hospital stay, ICU care and mortality in adults of all ages with chronic underlying conditions. Presenting signs and symptoms are nonspecific, co-infections occur, and patients often receive antibiotics and anti-influenza therapy. There is need for ongoing research and development of RSV prophylaxis, vaccines and treatments for adults.
authors.forename: Cheryl
authors.initials: C
authors.lastname: Volling
authors.forename: Kazi
authors.initials: K
authors.lastname: Hassan
authors.forename: Tony
authors.initials: T
authors.lastname: Mazzulli
authors.forename: Karen
authors.initials: K
authors.lastname: Green
authors.forename: Ahmed
authors.initials: A
authors.lastname: Al-Den
authors.forename: Paul
authors.initials: P
authors.lastname: Hunter
authors.forename: Rupi
authors.initials: R
authors.lastname: Mangat
authors.forename: John
authors.initials: J
authors.lastname: Ng
authors.affiliation: Department of Microbiology, Mount Sinai Hospital, Room 210, 600 University Avenue, Toronto, M5G 1X5, ON, Canada. amcgeer@mtsinai.on.ca.
authors.forename: Allison
authors.initials: A
authors.lastname: McGeer
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002170:Canada; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D007362:Intensive Care Units; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D012121:Respiration, Artificial; D018357:Respiratory Syncytial Virus Infections / Q000453:epidemiology* / Q000628:therapy; D012189:Retrospective Studies; D055815:Young Adult