title: Severe influenza in children: incidence and risk factors.
abstract: The identification of factors that can predispose to the development of severe influenza is essential to enable the implementation of optimal prevention and control measures for vulnerable populations.
  
  
  
  Unfortunately, data in the pediatric age group remain difficult to interpret. However, epidemiological data seem to suggest that the most severe influenza cases, those who are hospitalized, those who are admitted to the intensive care unit, and those who died, occur in children in the first 2 years of life and in school age patients. Expert commentary: Immaturity of the immune system, and in particular of the mechanisms that usually recognize influenza viruses and activate cytokine and chemokine responses to reduce viral replication, might explain the high hospitalization rate observed in the youngest patients. Some underlying chronic conditions favour the development of the severe cases, sometime leading to death, although both admission to the intensive care unit and death can occur in otherwise healthy subjects.
authors: a Pediatric Highly Intensive Care Unit, Department of Pathophysiology and Transplantation , Università degli Studi di Milano, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico , Milan , Italy.
authors: Nicola
authors: N
authors: Principi
authors: a Pediatric Highly Intensive Care Unit, Department of Pathophysiology and Transplantation , Università degli Studi di Milano, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico , Milan , Italy.
authors: Susanna
authors: S
authors: Esposito
mesh_terms: D056704:Adaptive Immunity / Q000235:genetics; D000293:Adolescent; D000367:Age Factors; D000818:Animals; D002648:Child; D002675:Child, Preschool; D003422:Critical Care; D020022:Genetic Predisposition to Disease / Q000235:genetics; D006801:Humans; D007113:Immunity, Innate / Q000235:genetics; D015994:Incidence; D007223:Infant; D007251:Influenza, Human / Q000453:epidemiology* / Q000209:etiology* / Q000276:immunology / Q000821:virology; D029521:Alphainfluenzavirus / Q000302:isolation & purification / Q000472:pathogenicity; D029524:Betainfluenzavirus / Q000302:isolation & purification / Q000472:pathogenicity; D012307:Risk Factors; D012720:Severity of Illness Index
keywords: Children; influenza; paediatric age; prevention; severe influenza; vaccine