Young children still bear burden of influenza

The 2012-2013 influenza season has not yet reached its halfway point, but already 18 pediatric deaths have been reported nationwide. A new study from the Centers for Disease Control and Prevention (CDC) finds that despite expanded vaccine recommendations, many young children are not sufficiently protected against seasonal influenza.

In 2008, the Advisory Committee on Immunization Practices of the CDC expanded its influenza vaccination recommendation to all children aged 6 months and older in the hope that widespread immunization would decrease the disease burden in children.

The CDC study evaluated data from the New Vaccine Surveillance Network for 2004 through 2009 to determine changes in the burden of laboratory-confirmed influenza, vaccine coverage, and the frequency of physician-ordered influenza tests, influenza-specific discharge diagnoses, and antiviral prescriptions for children. Researchers looked at laboratory-confirmed cases of influenza in children aged younger than 5 years who presented with fever and acute respiratory illness to hospitals, emergency departments (EDs), and outpatient clinics during the 5 influenza seasons (November through April) in 3 US counties.

Single-season hospitalization rates were 0.4 to 1 per 1,000 children and highest for babies aged younger than 6 months. Influenza testing among children with study protocol-confirmed influenza also was highest among hospitalized infants, as were discharges with influenza-specific diagnoses. The data suggest that physicians’ awareness of influenza in babies has increased.

Immunization rates among the hospitalized children were below 50%. Through the 5 study seasons, fewer than 45% of influenza-negative children aged 6 months or older were fully vaccinated against seasonal influenza.

Pediatric deaths attributed to influenza have plummeted from 282 in 2009-2010 to 18 so far in 2012-2013. However, the CDC says that seasonal influenza remains a significant cause of pediatric hospitalizations and ED and outpatient visits. Additional efforts are needed to ensure immunization of all children aged older than 6 months and of pregnant women, which also helps to protect younger infants.