SAN DIEGO – Influenza can be deadly even in children with no underlying high-risk conditions, results from a national 8-year study demonstrated.
"Because kids with and without high-risk medical conditions can die quickly from influenza, prevention is the best defense, and all children 6 months of age or older should receive influenza vaccination annually," lead study investigator Dr. Karen K. Wong said in an interview prior to IDWeek 2012, where the research was presented.
Dr. Karen K. Wong
Dr. Wong, an epidemic intelligence service officer with the influenza division at the Centers for Disease Control and Prevention, and her associates evaluated data from 829 influenza-associated deaths among children under age 18 that occurred in the United States between Oct. 1, 2004, and Sept. 30, 2012. Their median age was 7 years, and 35% of children died in the emergency department or outside the hospital.
Of the 793 children with a known medical history, 341 (43%) had no high-risk medical conditions, 33% reported neurologic disorders, 26% reported pulmonary disorders including asthma, and 12% reported genetic or chromosomal disorders. These exceeded 100% because more than one medical condition could be reported for a child.
The median duration of illness from symptom onset to death was shorter among children with no underlying high-risk medical conditions than in children with at least one high-risk medical condition (4 vs. 7 days, respectively; P less than .01).
Of 386 children with a specimen collected for bacterial culture from a normally sterile site whose results were available, 153 (40%) had at least one bacterial coinfection. Of those 153 children, the most common bacterial coinfection was Staphylococcus aureus, which was identified in 76 cases (50%).
"Influenza-associated deaths in children are rare," Dr. Wong said. "By including all reported influenza-associated pediatric deaths over an 8-year period in the United States, this study builds on prior smaller studies to describe the children at risk."
She said that she and her associates were surprised to find that 43% of the children who died of influenza-related illness "did not have any medical conditions that placed them at higher risk for influenza complications. Compared with children with high-risk conditions, these otherwise healthy children tended to be younger, and they were more likely to progress to death rapidly before being admitted to the hospital."
Dr. Wong acknowledged certain limitations of the study, including the fact that it was not designed to evaluate the impact of any interventions, such as vaccination or antiviral treatment. "Also, the national influenza-associated pediatric mortality surveillance system likely underestimates the true burden of influenza-associated death in children," she said.
IDWeek 2012 is the combined annual meetings of the Infectious Diseases Society of America, the Society for Healthcare Epidemiology of America, the HIV Medicine Association, and the Pediatric Infectious Diseases Society.
Dr. Wong said that she had no relevant financial disclosures.