title: Unchanged severity of influenza A(H1N1)pdm09 infection in children during first postpandemic season.
abstract: We conducted a nationwide hospital-based prospective study in Germany of influenza A(H1N1)pdm09 cases among children <15 years of age admitted to pediatric intensive care units and related deaths during the 2009-10 pandemic and the 2010-11 postpandemic influenza seasons. We identified 156 eligible patients: 112 in 2009-10 and 44 in 2010-11. Although a shift to younger patients occurred in 2010-11 (median age 3.2 vs. 5.3 years), infants <1 year of age remained the most affected. Underlying immunosuppression was a risk factor for hospital-acquired infections (p = 0.013), which accounted for 14% of cases. Myocarditis was predictive of death (p = 0.006). Of the 156 case-patients, 17% died; the difference between seasons was not significant (p = 0.473). Our findings stress the challenge of preventing severe postpandemic influenza infection in children and the need to prevent nosocomial transmission of influenza virus, especially in immunosuppressed children.
authors.affiliation: Robert Koch Institute, Department for Infectious Disease Epidemiology, Respiratory Infections Unit, Postfach 65 02 61, 13302 Berlin, Germany. altmannm@rki.de
authors.forename: Mathias
authors.initials: M
authors.lastname: Altmann
authors.forename: Lena
authors.initials: L
authors.lastname: Fiebig
authors.forename: Silke
authors.initials: S
authors.lastname: Buda
authors.forename: Rüdiger
authors.initials: R
authors.lastname: von Kries
authors.forename: Manuel
authors.initials: M
authors.lastname: Dehnert
authors.forename: Walter
authors.initials: W
authors.lastname: Haas
mesh_terms: D000293:Adolescent; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D003428:Cross Infection / Q000453:epidemiology; D005858:Germany; D049674:History, 21st Century; D006801:Humans; D007223:Infant; D053118:Influenza A Virus, H1N1 Subtype; D007251:Influenza, Human / Q000453:epidemiology* / Q000266:history; D058873:Pandemics; D011159:Population Surveillance; D011446:Prospective Studies; D012307:Risk Factors; D012621:Seasons