Flu hitting younger and middle-age adults hardest this season

Younger and middle-age adults make up the majority of hospitalizations and deaths from influenza this season, matching rates not seen since the 2009 H1N1 flu pandemic, federal health officials said Thursday.

Data collected by the Centers for Disease Control and Prevention show people between ages 18 and 64 have accounted for 61% of flu hospitalizations since September through Feb. 8. That's almost double the average rate of 35% over the past three seasons, according to the CDC's Morbidity and Mortality Weekly Report.

“Influenza can make anyone very sick, very fast, and it can kill,” CDC Director Dr. Tom Frieden said.

Frieden urged healthcare providers not to wait to treat patients with flu symptoms. “It's important that everyone get vaccinated,” he said. “It's also important to remember that some people who get vaccinated may still get sick, and we need to use our second line of defense against flu: antiviral drugs to treat flu illness. People at high risk of complications should seek treatment if they get a flu-like illness. Their doctors may prescribe antiviral drugs if it looks like they have influenza."

The H1N1 strain of the virus, which the World Health Organization said was responsible for about 18,000 deaths worldwide in 2009, has resurfaced this year.

The CDC said deaths from influenza this season are following similar patterns from those observed during that pandemic. As in 2009-2010, about 60% of flu deaths in the past five months have been people between ages 25 and 64.

Flu vaccinations have been effective this season, reducing a person's risk of seeking medical help by about 60%, according to a second report this week in the MMWR.

Follow Steven Ross Johnson on Twitter: @MHSjohnson