There have been at least 24 million illnesses, 310,000 hospitalizations and 13,000 deaths from flu so far this season, according to the CDC. The agency said in its weekly flu surveillance report that seasonal influenza activity continues to increase across the country.

Levels of influenza nationwide are now at the highest they have been since the peak of the 2009 swine flu pandemic, according to figures published Friday by the Centers for Disease Control and Prevention,

The flu continues to drive the most respiratory illness activity and officials warn that flu-related emergency department visits are expected to remain high in the coming weeks. Nineteen states reported high respiratory virus activity: South Dakota,