title: Clinical presentations and outcomes of influenza infection among hematology/oncology patients from a single cancer center: pandemic and post-pandemic seasons.
abstract: BACKGROUND
  Influenza can cause severe infection in hematology/oncology patients. The occurrence of the 2009 pandemic represented an opportunity to study the impact of influenza on such patients in pandemic and post-pandemic seasons.
  
  
  METHODS
  We retrospectively reviewed medical records of hematology/oncology patients who had laboratory-confirmed influenza infection during the 2009 pandemic and the first post-pandemic seasons. We assessed influenza-related outcomes in both seasons with emphasis on the development of pneumonia and mortality. We also analyzed factors associated with poor outcomes.
  
  
  RESULTS
  We included 350 patients; 207 were diagnosed in the pandemic and 143 in the post-pandemic seasons. Influenza severity was similar in both seasons with no significant differences in the development of pneumonia or death. Infection with the pH1N1 virus was associated with the development of pneumonia (24.7% vs 14.9%, p = 0.029) but did not affect mortality. A multivariate analysis showed that initiation of antiviral treatment after > 48 h, healthcare acquisition of influenza, and low albumin were independent risk factors for the development of pneumonia (p values 0.022, 0.003, and < 0.0001, respectively). A log-rank test showed increased mortality in patients who received therapy > 48 h after onset of symptoms (p = 0.001).
  
  
  CONCLUSIONS
  In hematology/oncology patients, influenza was as severe in the post-pandemic as in the pandemic season. Pneumonia developed more commonly in patients infected with pH1N1 virus. Healthcare acquisition of infection and low albumin were associated with the development of pneumonia. Delayed initiation of antiviral treatment was associated with both pneumonia and mortality.
authors.affiliation: From the Department of Medicine, King Hussein Cancer Center , Amman , Jordan.
authors.forename: Mustafa
authors.initials: M
authors.lastname: Saad
authors.forename: Wail
authors.initials: W
authors.lastname: Hayajneh
authors.forename: Sawsan
authors.initials: S
authors.lastname: Mubarak
authors.forename: Ibraheem
authors.initials: I
authors.lastname: Yousef
authors.forename: Hazem
authors.initials: H
authors.lastname: Awad
authors.forename: Wafa
authors.initials: W
authors.lastname: Elbjeirami
authors.forename: Rawad
authors.initials: R
authors.lastname: Rihani
mesh_terms: D000293:Adolescent; D000328:Adult; D000998:Antiviral Agents / Q000627:therapeutic use; D002173:Cancer Care Facilities; D002648:Child; D002675:Child, Preschool; D005260:Female; D019337:Hematologic Neoplasms / Q000821:virology*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D053118:Influenza A Virus, H1N1 Subtype / Q000302:isolation & purification*; D007251:Influenza, Human / Q000188:drug therapy* / Q000453:epidemiology / Q000473:pathology* / Q000821:virology; D007597:Jordan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D000998:Antiviral Agents
keywords: 2009 pandemic; H1N1 influenza; hematology; oncology; post-pandemic