FRIDAY, Jan. 18 (HealthDay News) -- Forty-eight states are now reporting widespread flu activity, up from 47 last week, and the virus is proving particularly dangerous for the elderly, U.S. health officials reported Friday.
In addition, the number of children who have died from the flu continues to rise. So far 29 children have died, nine more than was reported last week, according to the U.S. Centers for Disease Control and Prevention.
While there's no system to report adult deaths from flu, the CDC said Friday that 8.3 percent of all deaths in 122 cities were caused by pneumonia and flu. This is higher than the 7.2 percent the agency uses to define as the threshold for a flu epidemic.
"We are in the middle of flu season, about halfway through, and it's shaping up to be a worse-than-average season and a bad season, particularly, for the elderly," CDC director Dr. Thomas Frieden said during a Friday news conference.
He said that many parts of the country are still seeing high -- and in some cases increasing -- levels of activity from the H3N2 form of the flu virus, while in other regions rates of infection are starting to fall.
But the flu is taking a disproportionate toll on seniors, Frieden said.
"Last week hospitalization rates increased sharply in people 65 and over, and this week hospitalization rates for people 65 and over increased sharply again -- to 82 per 100,000, which is really quite a high rate," he said. "In general, we estimate that about 90 percent of flu-related deaths are in people 65 and older."
The 29 pediatric deaths so far compare to 153 deaths reported during the 2003-2004 season, which was another H3N2 season. "But we are only in the middle of the season," Frieden noted, adding that last year 122 children died from the flu.
An estimated 36,000 people die from the flu and its complications in a typical season, according to the CDC. From 1976 to 2006, estimates of flu-associated deaths in the United States ranged from a low of about 3,000 to a high of about 49,000 people.
The predominant strain of circulating flu this season continues to be influenza A H3N2, which typically poses bigger problems for young children and the elderly, followed by influenza B, according to the CDC.
However, the predominant strains can vary across states and regions of the country, the agency noted.
Frieden said there are continued reports of vaccine shortages in certain areas of the country. The companies that make vaccine for the United States projected that a total of 135 million doses would be available. They are, however, able to make additional vaccines for a total of 145 million. So far 129 million doses have been distributed, he said.
People can look on the web at Flu.gov to see where vaccine is available in their area, Frieden said.
Flu season usually peaks in late January or early February, but by November the flu was already severe and widespread in some parts of the South and Southeast.
The best defense against the flu remains the flu vaccine and it's not too late to get vaccinated, the CDC said.
This year's vaccine appears to be well matched for the circulating flu strains, the CDC said. A recent report put the vaccine's effectiveness at 62 percent. No vaccine is 100 percent effective. But if flu strikes, vaccination often results in milder illness, the agency said.
Two antiviral medications, Tamiflu and Relenza, can reduce flu symptoms and the course of the disease. To be effective, however, they must be started within 48 hours after symptoms appear. To increase the supply of Tamiflu, Dr. Margaret Hamburg, commissioner of the U.S. Food and Drug Administration, said at the news conference that the agency is allowing Tamiflu's manufacturer, Genentech, to distribute reserve doses that contain old packaging information. These doses aren't out-of-date, only the package insert is, she said.
Flu symptoms include fever, cough, fatigue, head and body aches, and runny nose. People at particular risk for flu and its complications are pregnant women, those 65 and older and anyone with a chronic illness. The CDC urges these people to get the flu vaccine, which is available as an injection or nasal spray and in a stronger dose for seniors.
The CDC recommends that everyone 6 months of age and older get vaccinated.
For more on flu, visit the U.S. Centers for Disease Control and Prevention.
SOURCES: Jan. 18, 2013, news conference with Thomas Frieden, M.D., M.P.H., director, U.S. Centers for Disease Control and Prevention, and Margaret Hamburg, M.D., commissioner, U.S. Food and Drug Administration; Jan. 18, 2013, U.S. Centers for Disease Control and Prevention, FluView