title: Comparison of hospitalized solid organ transplant recipients and nonimmunocompromised patients with pandemic H1N1 infection: a retrospective cohort study.
abstract: BACKGROUND
  Pandemic H1N1 influenza has been associated with a worldwide outbreak of febrile respiratory illness. Although impaired cell mediated immunity, such as that caused by transplant immunosuppression, has been identified as a risk factor for severe infection with this virus, the course of this infection has not been adequately characterized in solid organ transplant (SOT) recipients in comparison with nontransplanted controls. We report our experience with severe pH1N1 infection in transplant recipients and compare this group with nonimmunosuppressed patients.
  
  
  METHODS
  Data were retrospectively collected on all patients admitted to our institution with proven pH1N1 infection. Clinical characteristics, treatments, and outcomes were compared between SOT recipients and nonimmunocompromised controls.
  
  
  RESULTS
  Seventeen SOT recipients and 49 controls were identified. The control group had higher baseline rates of asthma (P = 0.02) and smoking (P = 0.05) at baseline. No difference in clinical features of H1N1 infection was detected except for a greater prevalence of wheeze in the non-SOT group (P = 0.02). No statistical differences in outcomes could be detected between the groups. Several markers of severity, including use of high frequency oscillatory ventilation, extracorporeal membrane oxygenation, and death were slightly more frequent in the control group.
  
  
  CONCLUSIONS
  SOT recipients admitted to hospital with pH1N1 infection did not have significantly more severe outcomes of their infection compared with their nonimmunocompromised counterparts, despite their immune suppressed status.
authors.affiliation: Division of Infectious Diseases, Department of Medicine, University of Toronto, Toronto, ON, Canada.
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Minnema
authors.forename: Mehul
authors.initials: M
authors.lastname: Patel
authors.forename: Coleman
authors.initials: C
authors.lastname: Rotstein
authors.forename: Tony
authors.initials: T
authors.lastname: Mazzulli
authors.forename: Susy
authors.initials: S
authors.lastname: Hota
authors.forename: Edward H
authors.initials: EH
authors.lastname: Cole
authors.forename: Eberhard L
authors.initials: EL
authors.lastname: Renner
authors.forename: Heather J
authors.initials: HJ
authors.lastname: Ross
authors.forename: Lianne G
authors.initials: LG
authors.lastname: Singer
authors.forename: Shahid
authors.initials: S
authors.lastname: Husain
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002170:Canada; D015331:Cohort Studies; D015199:Extracorporeal Membrane Oxygenation; D005260:Female; D006612:High-Frequency Ventilation; D006801:Humans; D016867:Immunocompromised Host; D053118:Influenza A Virus, H1N1 Subtype; D007251:Influenza, Human / Q000453:epidemiology* / Q000503:physiopathology / Q000628:therapy; D007297:Inpatients; D008297:Male; D008875:Middle Aged; D016377:Organ Transplantation; D058873:Pandemics; D015995:Prevalence; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D014180:Transplantation; D016896:Treatment Outcome