Too few in U.S. seek flu treatment, CDC says

* 26.6 million vaccines now produced

* Hospitals busy but not always with right patients

* Obama frustrated with vaccine delays

By Maggie Fox, Health and Science Editor

WASHINGTON, Oct 30 (Reuters) - Only half of the people in the United States who most need immediate treatment for H1N1 swine flu are actually seeking it, even as the virus spreads at unprecedented speed, U.S. health officials said on Friday.

The latest count shows 114 children have been killed by the virus in the United States since April, during a time when there is usually virtually no influenza, said U.S. Centers for Disease Control and Prevention Director Dr. Thomas Frieden.

H1N1 is widespread, he said, and case counts continue to rise in most states.

"One of the things that we have been surprised to see is even among people who have underlying conditions such as asthma, heart disease or lung disease, only half sought care," Frieden told reporters in a briefing.

At the same time, emergency departments were crowded but often with people who did not need medical care, he said.

CDC researchers estimated this week that as many as 5.7 million people in the United States have been infected so far, with at least 1,300 deaths.

The pandemic influenza is mild to moderate in most people but it can cause sudden, severe and overwhelming disease in certain groups, such as those with chronic disease.

Unlike seasonal influenza, which is dangerous mostly to the elderly, this new strain is hitting younger adults and children -- including at least a third with no previous health condition.

"People with underlying conditions who have fever or cough should see their provider promptly," Frieden said.

Frieden said the CDC had a cumulative 26.6 million doses of vaccine available -- far short of the 40 million that had been forecast for October. Lines have formed outside clinics as people seek the vaccine.

VACCINE FRUSTRATION

The CDC has designated about 160 million people as having priority, including pregnant women, children, healthcare workers and people under age 65 with underlying diseases.