FRIDAY, Jan. 18 (HealthDay News) -- Forty-eight states are now reporting widespread flu activity, up from 47 last week, U.S. health officials reported Friday.
In addition, the number of children who have died from 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.
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.
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.
In related news, the company that makes Tamiflu, an antiviral drug that can lessen the severity of flu, has released reserve stocks to combat shortages in some parts of the country, USA Today reported.
"With the addition of these reserve supplies, we anticipate having sufficient supply of Tamiflu capsules to meet demand for this flu season," said spokeswoman Tara Iannuccillo.
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.