Protecting the Young From Pandemic Flu

April 30, 2009— -- As swine flu spreads across the country and around the globe, its youngest victims may also be among the ones who are in the most danger of losing their lives, infectious disease experts say.

Their comments follow the first reported death in the United States from the swine flu -- a 22-month-old Mexican boy who had arrived at Texas Children's Hospital in Houston for treatment, but who died on Monday -- as well as the World Health Organization's decision to raise their pandemic alert level to phase 5 from phase 4.

"Classically, in seasonal influenza it is the very young and very old that die from influenza," said Dr. George Rutherford, director of the UCSF Institute for Global Health. "The CDC has not done full analysis on pediatric deaths this season, but last season 50 percent of childhood flu deaths occurred in those under 5 years old. The majority of these were in kids under age 2."

"Young children, especially those less than one year of age are particularly susceptible to influenza," agreed Dr. Rich Whitley, professor of medicine at the University of Alabama at Birmingham. "The younger the child, the more likely the severity will be greater, and risk for death increases."

Additionally, past research has shown that, in general, infants' immature immune systems make them more vulnerable to infection and death from viral infections like influenza.

But whether these past findings will be borne out with this new virus have yet to be seen, warns Ed Hsu, associate professor at the University of Texas School of Health Information Sciences and School of Public Health.

"We may need another week until the H1N1 outbreak runs the full course of its incubation and infectivity period," he said. "By this weekend we should have enough data to make some meaningful inferences from worldwide distribution of the disease, including susceptibility or vulnerability by age over time."

But while many infectious disease experts expect very young children to be more vulnerable to the new virus, it is a spike in deaths among young adults that could be a sign of a much more troubling outbreak.