Child deaths from swine flu are rising in the United States, with 19 flu-related deaths reported in the last week alone, U.S. health officials said Friday.

"Nineteen more pediatric deaths for influenza were reported to us this week. We're now up to 76 children having died from the 2009 H1N1 virus," said Anne Schuchat, of the Centers for Disease Control and Prevention.

"To put that in context: in the past three years, the total pediatric influenza deaths ranged from 46 - 88. We've already had 76 children dying from the H1N1 virus and it's only the beginning of October," said Schuchat, who is the director of CDC's National Center for Immunization and Respiratory Diseases.

She noted that 37 states now are reporting widespread swine flu cases, up from 27 a week ago. A week ago, reports suggested that cases might be leveling off and even decreasing in some areas of the country, but that did not turn out to be an enduring national trend.

"We are seeing more illness, more hospitalizations, and more deaths," she said.

The CDC doesn't keep an exact count of all swine flu deaths and hospitalizations. Existing reports suggest the virus has caused more than 600 deaths and more than 9,000 hospitalizations since first being identified in April.

The number of deaths among kids with swine flu had fallen during the summer, after peaking during the spring, said Schuchat. But they are "starting to shoot up again" with the autumn flu season, she said.

Children are deemed to be at particular risk from swine flu, and the CDC, along with Health Canada, recommends all children be vaccinated against the strain this fall.

The United States has already begun its massive vaccination campaign, though the vaccine is currently available only in a nasal spray. Children are one of five groups being given high priority for the vaccinations.

1 in 4 hospitalized sent to ICU

On Thursday, the CDC released a study that found one in four Americans who were hospitalized with swine flu last spring wound up needing intensive care. Of them, seven per cent died. That's a little higher than with ordinary seasonal flu, several experts said.

What is unusual is that children and teens accounted for nearly half of the hospitalized cases, including many who were previously healthy.

Three-quarters of these patients had other health problems, such as diabetes. Only five per cent were 65 and older, which is unusual, since ordinary seasonal flu usually hits hardest in the elderly.

Seven per cent of the hospitalized patients were pregnant, even though pregnant women make up only one per cent of the general population.

Among hospitalized patients whose weight was known, 26 per cent were very obese, confirming a risk factor suggested by other information from the outbreak.

The study was published online Thursday by the New England Journal of Medicine.

With reports from the Associated Press