title: Outcomes from pandemic influenza A H1N1 infection in recipients of solid-organ transplants: a multicentre cohort study.
abstract: BACKGROUND
  There are few data on the epidemiology and outcomes of influenza infection in recipients of solid-organ transplants. We aimed to establish the outcomes of pandemic influenza A H1N1 and factors leading to severe disease in a cohort of patients who had received transplants.
  
  
  METHODS
  We did a multicentre cohort study of adults and children who had received organ transplants with microbiological confirmation of influenza A infection from April to December, 2009. Centres were identified through the American Society of Transplantation Influenza Collaborative Study Group. Demographics, clinical presentation, treatment, and outcomes were assessed. Severity of disease was measured by admission to hospital and intensive care units (ICUs). The data were analysed with descriptive statistics. Proportions were compared by use of chi(2) tests. We used univariate analysis to identify factors leading to pneumonia, admission to hospital, and admission to an ICU. Multivariate analysis was done by use of a stepwise logistic regression model. We analysed deaths with Kaplan-Meier survival analysis.
  
  
  RESULTS
  We assessed 237 cases of medically attended influenza A H1N1 reported from 26 transplant centres during the study period. Transplant types included kidney, liver, heart, lung, and others. Both adults (154 patients; median age 47 years) and children (83; 9 years) were assessed. Median time from transplant was 3.6 years. 167 (71%) of 237 patients were admitted to hospital. Data on complications were available for 230 patients; 73 (32%) had pneumonia, 37 (16%) were admitted to ICUs, and ten (4%) died. Antiviral treatment was used in 223 (94%) patients (primarily oseltamivir monotherapy). Seven (8%) patients given antiviral drugs within 48 h of symptom onset were admitted to an ICU compared with 28 (22.4%) given antivirals later (p=0.007). Children who received transplants were less likely to present with pneumonia than adults, but rates of admission to hospital and ICU were similar.
  
  
  CONCLUSIONS
  Influenza A H1N1 caused substantial morbidity in recipients of solid-organ transplants during the 2009-10 pandemic. Starting antiviral therapy early is associated with clinical benefit as measured by need for ICU admission and mechanical ventilation.
  
  
  BACKGROUND
  None.
authors.affiliation: University of Alberta, Edmonton, AB, Canada. deepali.kumar@ualberta.ca
authors.forename: Deepali
authors.initials: D
authors.lastname: Kumar
authors.forename: Marian G
authors.initials: MG
authors.lastname: Michaels
authors.forename: Michele I
authors.initials: MI
authors.lastname: Morris
authors.forename: Michael
authors.initials: M
authors.lastname: Green
authors.forename: Robin K
authors.initials: RK
authors.lastname: Avery
authors.forename: Catherine
authors.initials: C
authors.lastname: Liu
authors.forename: Lara
authors.initials: L
authors.lastname: Danziger-Isakov
authors.forename: Valentina
authors.initials: V
authors.lastname: Stosor
authors.forename: Michele
authors.initials: M
authors.lastname: Estabrook
authors.forename: Soren
authors.initials: S
authors.lastname: Gantt
authors.forename: Kieren A
authors.initials: KA
authors.lastname: Marr
authors.forename: Stanley
authors.initials: S
authors.lastname: Martin
authors.forename: Fernanda P
authors.initials: FP
authors.lastname: Silveira
authors.forename: Raymund R
authors.initials: RR
authors.lastname: Razonable
authors.forename: Upton D
authors.initials: UD
authors.lastname: Allen
authors.forename: Marilyn E
authors.initials: ME
authors.lastname: Levi
authors.forename: G Marshall
authors.initials: GM
authors.lastname: Lyon
authors.forename: Lorraine E
authors.initials: LE
authors.lastname: Bell
authors.forename: Shirish
authors.initials: S
authors.lastname: Huprikar
authors.forename: Gopi
authors.initials: G
authors.lastname: Patel
authors.forename: Kevin S
authors.initials: KS
authors.lastname: Gregg
authors.forename: Kenneth
authors.initials: K
authors.lastname: Pursell
authors.forename: Doug
authors.initials: D
authors.lastname: Helmersen
authors.forename: Kathleen G
authors.initials: KG
authors.lastname: Julian
authors.forename: Kevin
authors.initials: K
authors.lastname: Shiley
authors.forename: Bartholomew
authors.initials: B
authors.lastname: Bono
authors.forename: Vikas R
authors.initials: VR
authors.lastname: Dharnidharka
authors.forename: Gelareh
authors.initials: G
authors.lastname: Alavi
authors.forename: Jayant S
authors.initials: JS
authors.lastname: Kalpoe
authors.forename: Shmuel
authors.initials: S
authors.lastname: Shoham
authors.forename: Gail E
authors.initials: GE
authors.lastname: Reid
authors.forename: Atul
authors.initials: A
authors.lastname: Humar
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D004196:Disease Outbreaks; D005260:Female; D006801:Humans; D007223:Infant; D053118:Influenza A Virus, H1N1 Subtype; D007251:Influenza, Human / Q000188:drug therapy / Q000453:epidemiology*; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D016377:Organ Transplantation / Q000009:adverse effects*