Health and Science

'Nastier' flu strain spreads, death toll rises

This flu season is already "bad" and getting worse, officials said Friday as they reported a spike in hospitalizations for the elderly and an increase in the number of children killed by the virus

"This flu season is shaping up to be a particularly severe one, particularly for older people and young children and people with underlying conditions," said Dr. Thomas Frieden, director of the federal Centers for Disease Control and Prevention.

"Flu is now widespread in almost the entire country."

Read MoreFlu boosts drug store sales, but others take a hit

Frieden blamed the severity of the season on the prevalence of the H3N2 flu strain, which "is a nastier virus than the other viruses."

A man receives a flu shot from a Walgreens employee during a free flu shot clinic at Allen Temple Baptist Church in Oakland, Calif.
Getty Images

Most of the cases this year have been from that strain. About two-thirds are from a mutated form of the H3N2 virus, reducing the efficacy of the flu vaccine designed to target an earlier form of the virus.

Read More9 measles cases linked to Disneyland in California

Frieden said there have been five more reported cases of children dying from influenza in the past week, bringing the pediatric death toll from flu to 26 this season.

Last year, 109 pediatric deaths were tied to the flu. Two years ago, when H3N2 was last prevalent, that number was 171.

CDC warns on flu epidemic
VIDEO0:5800:58
CDC warns on flu epidemic

The rate of hospitalization for people age 65 and over is now 92 per 100,000 people, compared with 52 the previous week.

Two years ago, the hospitalization rate reached a high of 183 elderly people per 100,000, "and we wouldn't be surprised to see something similar" this season, Frieden said.

Up to 50,000 people each year die from the flu.

Read MoreBreaking into the breakout sessions

Frieden noted that flu seasons, on average, last around 13 weeks. The current season has lasted seven weeks. He urged people to get vaccinated and to take anti-viral medication if they get the flu.

"If you have influenza and you get medications early you may not be admitted to the hospital," he said. "Prompt treatment with these anti-virals can even save your life."