The state health department reports 748 hospitalizations as of January 4. That's up from 263 as of December 21. Hospitalizations also are higher than a year ago at this time when 506 were reported.
"It is definitely not too late to get a flu shot," said Dr. Lisa Miller, a spokeswoman for the health department. "We recommend getting a flu shot as long as flu is still circulating in the state, and the flu is definitely still circulating."
She adds that vaccines also are available.
The health department reports virtually all influenza viruses currently circulating in Colorado are the 2009 H1N1 virus. Miller said that particular virus affects young people more than most.
The flu virus has now been reported in 45 Colorado Counties up from 25 counties two weeks ago.