Longer flu season sending more to hospital

Influenza is sending more people to the hospital in the United States each year, and the flu season appears to be getting longer, a government study has found.

The increased hospital admissions are partly due to an aging population that is more susceptible to the annual malady, the report from the federal Centers for Disease Control and Prevention said.

The study, released Tuesday, looked at hospital records from 1979 to 2001.

“Currently, we estimate that more than 200,000 respiratory and circulatory hospitalizations are associated with influenza each year in the United States ... and the numbers of these hospitalizations have increased substantially over the last two decades due in part to the aging of the population,” the report stated.

William Thompson, the report’s chief author, said: “We’re also seeing that the influenza season is lasting longer ... going from a period of about eight weeks in length to 12 weeks in length.”

The study did not examine why the season is getting longer, but a spokeswoman for the agency said the CDC was currently exploring that question.