THURSDAY, Sept. 2, 2009 (HealthDay News) -- Nearly 500 Americans have died of complications from the H1N1 swine flu since the virus first surfaced last spring, including at least 36 children younger than 18, a new government report shows.
And 67 percent of those children who died had at least one chronic high-risk "neurodevelopmental condition," such as epilepsy, cerebral palsy or developmental delay, U.S. health officials said during a news conference Thursday.
Bacterial infections -- such as bacterial pneumonia -- were another contributing factor to an increased risk of death in children, including most children older than 5 who didn't have a preexisting high-risk medical condition. This suggests that bacteria, in tandem with the H1N1 virus, can cause severe disease in children who may be otherwise healthy, the officials said.
But the officials, from the U.S. Centers for Disease Control and Prevention, stressed that the pediatric death rates and complications from swine flu are very similar to the rates of death and complications seen in children sickened by the seasonal flu each year.
"Each year, there are 50 to 100 deaths from influenza among children in this country," CDC Director Dr. Thomas R. Frieden said during the afternoon news conference. "These [swine flu] findings are not unexpected. It's what we see with seasonal flu. But only time will tell what will happen in the fall and winter."
The officials noted one difference in death rates of children stricken with seasonal flu vs. the newly identified swine flu. In past seasonal flu outbreaks, the children who died tended to be 5 or younger. But since the H1N1 virus first surfaced in mid-April, the death rates have been higher for children older than 5, according to a report in the Sept. 4 issue of the CDC's Morbidity and Mortality Weekly Report.
CDC officials continued to emphasize that for most people, adults included, infection with the H1N1 swine flu produces mild illness and the recovery is fairly quick. And the virus has shown no signs of mutating into a more virulent form during its travels from the northern hemisphere to the southern hemisphere.
Frieden said children, particularly those with underlying medical conditions, need to be treated promptly if they develop a fever, and "are at the front of the line for vaccination when it becomes available."
Federal health officials expect an initial shipment of 45 million swine flu vaccine doses to be ready by mid-October.
The CDC is recommending that all children aged 6 months and older be vaccinated against the swine flu virus. Children should also be vaccinated for seasonal flu, Frieden said.
Dr. Pascal James Imperato, dean and distinguished service professor in the School of Public Health at SUNY Downstate Medical Center in New York City, said, "Young children with serious medical conditions are always at greater risk for severe illness and death from seasonal influenza compared to their healthy counterparts."
The H1N1 deaths of children younger than 18 last spring documented by the CDC confirm that such risk also exists with the swine flu virus, Imperato said.
"There is nothing surprising in this finding," he said. "It is significant that of the children who died, 22 had neurodevelopmental conditions, which obviously placed them at special high risk. Such children should clearly be high in the priority list for immunization not only against the H1N1 swine flu, but also against the seasonal flu."
Besides children and young adults, who seem to lack immunity to the H1N1 virus, pregnant women, people with preexisting health problems, such as diabetes, and health-care workers also top the CDC's list of vaccine candidates once it becomes available.
Dr. Marc Siegel, an associate professor of medicine at New York University Langone Medical Center in New York City, said the new CDC report "emphasizes the need for antivirals in children who are sick, as well as vaccination of all children as soon as it is available."
"Since infants cannot be vaccinated before 6 months and won't be able to mount an immune response, this also emphasizes the need of pregnant women to receive the vaccine as soon as available," he added.
As H1N1 vaccine testing continues, the CDC is looking for any adverse side effects from the inoculation, Frieden said.
"We know that every year, there are cases of paralysis, Guillain-Barre syndrome, there are women who have miscarriages, there are people who have sudden death," Frieden said, referring to side effects from seasonal flu vaccines.
"In all of those situations, we need to know very clearly how many we would expect if the vaccine doesn't cause any problems whatsoever," he said, referring to the swine flu vaccine.
Frieden noted that with the start of school, cases of H1N1 infection are on the rise, particularly in the southeastern United States where schools got under way earlier than in many other parts of the country.
"With school resuming, we do expect to see more cases," Frieden said. "We are seeing it now, and we expect that will continue."
For more on H1N1 swine flu, visit Flu.gov.