Multistate surveillance for laboratory-confirmed, influenza-associated hospitalizations in children: 2003-2004

Pediatr Infect Dis J. 2006 May;25(5):395-400. doi: 10.1097/01.inf.0000214988.81379.71.

Abstract

Background: Increasing use of rapid influenza diagnostics facilitates laboratory confirmation of influenza infections. We describe laboratory-confirmed, influenza-associated hospitalizations in a population representing almost 6% of children in the United States.

Methods: We conducted population-based surveillance for influenza-associated hospitalizations between October 1, 2003, and March 31, 2004, in 54 counties in 9 states (4.2 million children) participating in the Emerging Infections Program Network. Clinical characteristics, predictors of intensive care unit admission and geographic and age-specific incidence were evaluated.

Results: Surveillance identified 1,308 case-patients; 80% were <5 years and 27% were <6 months of age. Half of the patients and 4 of 5 pediatric deaths did not have a medical indication for influenza vaccination and were outside the 6- to 23-month age group. Twenty-eight percent of case-patients had radiographic evidence of a pulmonary infiltrate, 11% were admitted to intensive care and 3% received mechanical ventilation. The median length of hospital stay was 2 days. Community-acquired invasive bacterial coinfections (1% of patients) were associated with intensive care admission (adjusted odds ratio, 16.9; 95% confidence interval, 5.0-56.8). Thirty-five percent of patients >or=6 months old had received at least one influenza vaccine dose that season. The overall incidence of influenza-associated hospitalizations was 36 per 100,000 children (range per state, 10 per 100,000 to 86 per 100,000).

Conclusions: Influenza was an important cause of hospitalizations in children during 2003-2004. Hospitalizations were particularly common among children <6 months of age, a group for whom influenza vaccine is not licensed. Continued surveillance for laboratory-confirmed influenza could inform prevention strategies.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adolescent
  • Age Distribution
  • Child
  • Child, Preschool
  • Clinical Laboratory Techniques
  • Female
  • Hospitalization / statistics & numerical data*
  • Humans
  • Incidence
  • Infant
  • Influenza, Human / diagnosis*
  • Influenza, Human / epidemiology*
  • Influenza, Human / virology
  • Laboratories, Hospital*
  • Male
  • Population Surveillance*
  • United States / epidemiology