Also, as anecdotal reports and at least one poll showed that many Americans are nervous about the vaccine, officials emphasized that the new shots were nearly identical to seasonal ones, and said they were doing what they could to debunk myths about the vaccine.
Dr. Anne Schuchat, the disease control center’s director of immunization and respiratory disease, said there was “significant flu activity in virtually all states,” which, she added, was “quite unusual for this time of year.”
Dr. Schuchat expressed particular worry about pregnant women. As of late August, 100 had been hospitalized in intensive care, and 28 had died since the beginning of the outbreak in April.
“These are really upsetting numbers,” she said, urging obstetricians and midwives to advise patients to get swine flu shots as soon as they become available.
Also on Thursday, a 23-year-old recruit in basic training in Fort Jackson, S.C., was acknowledged Thursday to be the Army’s first swine flu death. The recruit, Specialist Christopher M. Hogg of Deltona, Fla., fell ill on Sept. 1 and died of pneumonia on Sept. 10, the military said. Although Specialist Hogg initially tested negative for swine flu, it was found on autopsy.
About 50,000 troops a year train at Fort Jackson. (The camp was hit hard by the Spanish influenza in 1918, when up to 5 percent of the recruits died, according to a military historian quoted by The Associated Press.)
Flu cases are rising in many parts of the country, according to local news media reports.
Dell Children’s Medical Center in Austin, Tex., erected two tents in its parking lot to handle emergency room visits, and hospitals near Colorado Springs had a 30 percent spike in flu visits. Several North Carolina hospitals barred children from visiting.
Because pediatric cases are increasing, the Department of Health and Human Services on Tuesday released 300,000 courses of children’s liquid Tamiflu from the national pandemic stockpile, with the first batches going to Texas and Colorado.
Some was past its expiration date, Dr. Schuchat said, but the Food and Drug Administration tested the stocks and certified them as still usable.
More than 99 percent of all swine flu cases are mild to moderate, but millions of people with relatively common problems like asthma, obesity, diabetes or heart problems are at higher risk, as are pregnant women and infants too young for vaccine.
The last disease centers count of child deaths from the flu was 36 as of Aug. 8. Since then, there have been reports of children dying in several states, mostly in the South, where schools reopened earlier.
Last week, the centers reported that 936 Americans had died of flu symptoms or of flu-associated pneumonia since Aug. 30, when it began a new count of deaths including some without lab-confirmed swine flu. That is few compared with the 36,000 that die annually of seasonal flu, but the deaths are concentrated in age groups that do not normally succumb, and the regular flu season will not arrive until November.
Confirming the centers’ anxiety that many Americans are reluctant to get swine flu shots, Consumer Reports released a poll late Wednesday showing that half of all parents surveyed said they were worried about the flu, but only 35 percent would definitely have their children vaccinated. About half were undecided, and of those, many said they feared that the vaccine was new and untested.
One worrying aspect, said Dr. John Santa, the director of health ratings at Consumer Reports, was that 69 percent of parents who were undecided or opposed to shots said they “wanted their children to build up their natural immunity.”
“Your body produces exactly the same antibodies, whether it’s from a ‘natural’ infection or from a vaccine,” Dr. Santa said. “If your child is the one that dies, you’ve paid a very high price for ‘natural’ immunity.”
(The poll was a telephone survey of 1,502 adults from Sept. 2 to Sept. 7, with a margin of sampling error of plus or minus three percentage points.)
Dr. Schuchat argued that the vaccine was neither new nor untested.
It is attached to the same “genetic backbone” of weakened flu virus as the 100 million seasonal flu injections given each year, grown in the same sterile eggs and purified in the same factories. And test injections done in September found that it had the same side effects, most of which were sore arms and mild fevers.
Scientists at the disease centers also looked at lung samples from 77 fatal swine flu cases and found that in about a third of the cases, the patient had died not from flu alone, but from bacteria that infiltrate when flu inflames the lungs.
The “good news,” Dr. Schuchat said, is that most infections were streptococcus pneumoniae, a common bacteria for which there is a vaccine. That vaccine is normally given only to people over 65 or with chronic heart and lung problems, but only about one in five Americans eligible for that shot ever gets it. More people in those categories should, she said.