The deadly H1N1 influenza virus, also known as swine flu, may have affected more than 57 million Americans and killed as many as 17,000 of them, according to new official estimates.
Though 2,498 confirmed deaths linked to the H1N1 virus had been reported to the Centers for Disease Control and Prevention (CDC) in Atlanta as of January 30, the agency estimates that between 8,330 and 17,160 people actually have died from H1N1.
The overwhelming majority of the people who died - between 6,390 and 13,170 - were 18 to 64 years old, according to the CDC estimates released Friday. Between 880 and 1,810 children 17 years old and younger also died from this flu, it estimated.
In comparison, the CDC says that in a regular flu season, about 36,000 people in the United States die from seasonal flu, with 90 percent of the deaths usually occurring in people age 65 and older.
While the new figures show the H1N1 pandemic virus is still spreading, they also reflect a slowdown in the transmission of the illnesses since last October. The CDC had last estimated about 55 million Americans had been sickened, 246,000 were hospitalised and about 11,100 had died through mid-December.
While health officials have yet to declare the end of the influenza pandemic, a new round of widespread illness is increasingly unlikely now that a substantial portion of the American population has been either sickened by or vaccinated against the H1N1 pandemic virus. About 70 million people have been vaccinated.
In a separate weekly report of H1N1 influenza activity, the CDC said most influenza strains circulating as of Feb 6 are the H1N1 strain and not strains that cause seasonal influenza.
As of Feb 6, the majority of states reported "sporadic" transmission of the H1N1 virus, the CDC said. However, the CDC said doctor visits for influenza-like illnesses increased slightly over the previous week but "remain low overall."