Less than 45 percent of American children under age five are vaccinated against the flu, even though health officials recommend that all children aged six months and older get the shot, according to a new study by researchers at the Wake Forest University in North Carolina.
"Our research showed that one in six children under age five who went to an emergency department or clinic with fever and respiratory symptoms during the peak flu seasons had the flu," said Katherine Poehling, associate professor of pediatrics and epidemiology at Wake Forest and lead author of the study, published in the online edition of the February issue of Pediatrics. "Many of those illnesses could have been prevented by vaccination, the best known protection against the flu."
The researchers found that children less than six months of age had the highest hospitalization rates with the flu. "Parents should include a yearly flu shot to protect themselves and their children," Poehling said. "The best way to protect infants too young to receive the influenza vaccine is for pregnant women, the infant's family members and contacts to get the shot, too."
The study, funded by the Centers for Disease Control and Prevention, reported population-based data on confirmed flu cases in children younger than five years old in three counties in Ohio, New York and Tennessee. More than 8,000 children seen in inpatient, emergency department and clinic settings were included during flu seasons from 2004 through 2009.
During the study period, the researchers found that the overall flu vaccination coverage changed little, whereas the rates of influenza hospitalization and prevalence of influenza among outpatients varied annually. The proportion of infants less than six months old diagnosed with flu increased to 48 percent as compared to 28 percent in a previous study (2000--2004) conducted by the research team.
However, for children between ages of six months and five years, the proportion diagnosed with the flu remained similar in both studies. These data suggest that doctors' awareness of the flu among young infants has increased, but hasn't among older children.
The study also showed that seasonal flu remains an important cause of hospitalization, emergency department and outpatient visits among children and that the use of tools known to reduce flu rates -- vaccination and antiviral medications -- were underused, Poehling said.