CDC: Swine flu more deadly to adolescents

Adolescents are at higher risk of dying of H1N1 influenza virus than younger children, a situation that is the opposite of that encountered with seasonal flu, federal health authorities said Thursday.

And those with underlying health problems, such as cerebral palsy, muscular dystrophy and neurodevelopmental disorders, are at the highest risk and should be among the first to be vaccinated against the new virus, according to the Centers for Disease Control and Prevention (CDC) report.

The government's warning takes on added urgency as schools begin to reopen and increases in infections from the virus, commonly known as swine flu, become apparent.

Swine-flu outbreaks are already occurring throughout the country, and they are highest in the Southeast.

"The most likely explanation is that schools started earlier there," said Dr. Thomas Frieden, director of the CDC.

From the time of the swine-flu outbreak in April, at least 40 children have died, accounting for about one in 13 U.S. swine-flu deaths, CDC scientists said.

Two-thirds of those already had high-risk health problems, confirming what officials have been saying about who is most vulnerable to swine flu.

It is not clear whether the new virus is more dangerous than ordinary seasonal flu for youngsters, though some health officials suspect it is. But the analysis shows some preliminary and important differences:

• Normally, half or more of the children who die of the flu are 4 or younger. But more than 80 percent of the children who died with swine flu were 5 through 17. Dr. Beth Bell, a CDC epidemiologist, said that may be because older children spend time at school and summer camp, exposed to more people than younger children kept at home.

• Almost two-thirds of the children who died had epilepsy, cerebral palsy or other neurodevelopmental conditions. In a previous flu season, only one-third of the children who died had those conditions.

• Other germs, working with swine flu in a one-two punch, were a big danger. A bacterial infection on top of the flu virus played a role in most of the deaths of otherwise healthy children.

Swine flu is now responsible for almost all flu cases in the United States.

It has caused more than 1 million illnesses, though most were mild and not reported, the CDC estimates. More than 550 lab-confirmed deaths and 8,800 hospitalizations have been reported.

Those statistics don't mean the new flu is worse than seasonal flu, which is particularly lethal to the elderly and plays a role in an estimated 36,000 deaths each year, the CDC says.

The findings emphasize the need for high-risk groups to be immunized against bacterial pneumonia, which can prevent some of the complications of flu, Frieden said.

The CDC is urging the majority of people with flu symptoms to avoid going to doctors or hospital emergency rooms to prevent the facilities from being swamped.

But children and adults with underlying medical conditions, and pregnant women, should seek treatment when a fever from the flu develops.