Severe influenza in children: incidence and risk factors

ABSTRACT

Introduction: 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.

Areas covered: 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.

KEYWORDS:

• Children
• influenza
• paediatric age
• prevention
• severe influenza
• vaccine

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Additional information

Funding

This review was supported by a grant obtained from the Italian Ministry of Health (Bando Giovani Ricercatori 2009 GR-2009-1596786).