title: First influenza season after the 2009 pandemic influenza: characteristics of intensive care unit admissions in adults and children in Vall d'Hebron Hospital.
abstract: To assess potential differences in epidemiology and management of patients admitted with influenza infection in the intensive care unit (ICU) during the first post-pandemic influenza period. Observational prospective study comparing September 2009-January 2010 with September 2010-January 2011. Variables captured: demographics, co-morbidities, physiological parameters, outcomes and management. Analysis was performed using SPSS v. 13.0; significance was set at p 0.5. Data from 53 patients, 38 adults (age, median 41.5 years; interquartile range (IQR) 32.8-51.3) and 15 children (age, median 2 years, IQR 0.5-9) are presented. Vaccination rates were 0% and 4.3% during the first and second periods, respectively. Differences postpandemic were: 100% of episodes developed after December compared with 16.7% in the 2009 season. Younger children were affected (median age 0.8 years (IQR 0.3-4.8) vs 7 years (IQR 1.25-11.5), p 0.05) and influenza B caused 8.7% of ICU admissions. Influenza A (H1N1) 2009 and respiratory syncytial virus epidemics occurred simultaneously (42.8% of children) and bacterial co-infections doubled (from 10% to 21.7%); the prevalence of co-infections (viral or bacterial) increased from 10% to 39.1% (OR 5.8, 95% CI 1.3-24.8). Respiratory syndromes without chest X-ray opacities reflecting exacerbation of asthma or chronic obstructive pulmonary disease, bronchitis or bronchiolitis increased (from 6.9% to 39.1%, p<0.05) and pneumonia decreased (from 83.3% to 56.5%, p <0.05). Primary viral pneumonia predominated among ICU admissions. Postpandemic ICU influenza developed later, with some cases of influenza B, more frequent bacterial and viral co-infections and more patients with severe acute respiratory infection with normal chest X-ray. Increasing vaccination rates among risk-group individuals is warranted to prevent ICU admission and death.
authors.affiliation: Department of Critical Care, Vall d'Hebron University Hospital, Barcelona, Spain.
authors.forename: G
authors.initials: G
authors.lastname: Poulakou
authors.forename: J
authors.initials: J
authors.lastname: Souto
authors.forename: J
authors.initials: J
authors.lastname: Balcells
authors.forename: M
authors.initials: M
authors.lastname: Pérez
authors.forename: C
authors.initials: C
authors.lastname: Laborda
authors.forename: O
authors.initials: O
authors.lastname: Roca
authors.forename: T
authors.initials: T
authors.lastname: Tórtola
authors.forename: M
authors.initials: M
authors.lastname: Pujol
authors.forename: M
authors.initials: M
authors.lastname: Palomar
authors.forename: J
authors.initials: J
authors.lastname: Rello
mesh_terms: D000293:Adolescent; D000328:Adult; D001419:Bacteria / Q000472:pathogenicity; D001424:Bacterial Infections / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000382:microbiology; D001991:Bronchitis / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000382:microbiology / Q000821:virology; D002648:Child; D002675:Child, Preschool; D060085:Coinfection / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000382:microbiology / Q000821:virology; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data; D006761:Hospitals / Q000706:statistics & numerical data*; D006801:Humans; D007223:Infant; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology / Q000472:pathogenicity; D009981:Influenza B virus / Q000276:immunology / Q000472:pathogenicity; D007251:Influenza, Human / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000821:virology; D007362:Intensive Care Units / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D058873:Pandemics; D011024:Pneumonia, Viral / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000821:virology; D015995:Prevalence; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000382:microbiology / Q000821:virology; D011859:Radiography; D012621:Seasons; D013030:Spain / Q000453:epidemiology; D013997:Time Factors; D014611:Vaccination; D055815:Young Adult