Influenza frequently causes fever and respiratory illness. Studies have found that children with underlying chronic conditions have a higher incidence of influenza than healthy children. This study examines the effects of asthma on influenza incidence in children. The researchers enrolled 1,468 children ages 6 to 59 months, across three U.S. counties, who were hospitalized with an acute respiratory illness or a fever. Also, a similar group of children were enrolled who presented to outpatient clinics and emergency departments during two influenza seasons.

Key Findings:

  • Of 81 hospitalized children with influenza, 19 of them had asthma.
  • Hospitalization rates were significantly higher among children with asthma than among healthy children (2.8 cases compared with 0.6 cases per 1000).
  • Of 249 children presenting at clinics with influenza, 38 had asthma. Visit rates for influenza were higher for children with asthma than for healthy children—316 cases compared to 152 cases per 1000 for children ages 6 to 23 months, and 188 cases compared to 102 cases per 1000 for children ages 24 to 59 months.

The study concludes that policy-makers must develop targeted strategies to increase the number of influenza vaccines for children with or without asthma.