title: Severe pandemic H1N1 and seasonal influenza in children and young adults with sickle cell disease.
abstract: Influenza causes excess morbidity in sickle cell disease (SCD). H1N1 pandemic influenza has been severe in children. To compare H1N1 with seasonal influenza in SCD (patients younger than 22), we reviewed medical records (1993-2009). We identified 123 cases of laboratory-confirmed influenza (94 seasonal, 29 H1N1). Those with seasonal influenza were younger (median 4.4 vs 8.7 years old, P = .006) and had less asthma (24% vs 56%, P = .002). Those with H1N1 influenza more often had acute chest syndrome (ACS; 34% vs 13%, P = .01) and required intensive care (17% vs 3%, P = .02), including mechanical ventilation (10% vs 0%, P = .02). In multivariate analysis, older age (odds ratio [OR] 1.1 per year, P = .04) and H1N1 influenza (OR 3.0, P = .04) were associated with ACS, and older age (OR 1.1 per year, P = .02) and prior ACS (OR 3.3 per episode in last year, P < .006) with intensive care. Influenza, especially H1N1, causes critical illness in SCD and should be prevented.
authors.affiliation: Division of Pediatric Hematology, Department of Pediatrics, Johns Hopkins University, Baltimore, MD, USA. jstrous1@jhmi.edu
authors.forename: John J
authors.initials: JJ
authors.lastname: Strouse
authors.forename: Megan E
authors.initials: ME
authors.lastname: Reller
authors.forename: David G
authors.initials: DG
authors.lastname: Bundy
authors.forename: Martha
authors.initials: M
authors.lastname: Amoako
authors.forename: Maria
authors.initials: M
authors.lastname: Cancio
authors.forename: Rachel N
authors.initials: RN
authors.lastname: Han
authors.forename: Alexandra
authors.initials: A
authors.lastname: Valsamakis
authors.forename: James F
authors.initials: JF
authors.lastname: Casella
mesh_terms: D000293:Adolescent; D000755:Anemia, Sickle Cell / Q000150:complications*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000302:isolation & purification*; D007251:Influenza, Human / Q000150:complications* / Q000175:diagnosis / Q000453:epidemiology* / Q000628:therapy; D008297:Male; D058873:Pandemics; D016896:Treatment Outcome; D055815:Young Adult